Peritoneal Cavity Notes

Peritoneum Peritoneal Cavity Mesentery And Retroperitoneum

Peritoneum Introduction

The peritoneal cavity is the largest cavity in the body accommodating various viscera. It is divided into greater and lesser sac (omental bursa) which communicate through the foramen of Winslow or epiploic foramen. The peritoneum lining inner side of the parietes is called parietal peritoneum. It is very sensitive and is innervated by both somatic and visceral afferent nerves. This explains the sharp, localised, cutting pain of peritonitis. Diaphragm and central part of the peritoneum is supplied by phrenic nerve (C4) and partly by intercostal nerves. Rest of the peritoneum is supplied by intercostal nerves and lumbar nerves.

Lesser omentum: It is also called hepatoduodenal ligament. It extends from the duodenum to the liver. This has two layers and within these layers are the common bile duct, hepatic artery and hepatic portal vein.

Read And Learn More: Gastrointestinal Surgery Notes

The Peritoneum

Lining of Peritoneum:

• The peritoneum is lined by simple squamous epithelium of mesodermal origin called mesothelium with surface area 1.0 to 1.7 m² and a thin layer of fibroelastic tissue.
• It is parietal peritoneum. A large peritoneal defect heals within a few hours because of these mesenchymal cells (flattened polyhedral cells—mesothelium).
• Applying this principle, some surgeons do not close the peritoneal layer after laparotomy.
• When parietal peritoneum is reflected into viscera, it is called visceral peritoneum.
• It covers viscera and is supplied by autonomic nervous system. Hence, it is not sensitive.
• Thus, gastrojejunostomy can be done under local anaesthesia but distension and traction to the bowel causes pain.
• During herniorrhaphy under spinal anaesthesia, handling of bowel or traction on the bowel can produce uncomfortable upper abdominal pain.
  • In men, peritoneal cavity is completely sealed, hence cannot get infected.
  • In women, it is communicated to exterior through fallopian tubes, hence infection can occur.

Peritoneal Cavity

Fluid

The peritoneal surface is a semipermeable membrane with an area comparable to that of a cutaneous body surface.

Nearly 1 m² of the total 1.7 m² area participates in fluid exchange with extracellular fluid space at the rate of 500 ml or more per hour.

It normally contains less than 50 ml of fluid. When it is insulted by infection, a large amount of fluid can collect in this space giving rise to severe fluid and electrolyte imbalance. This is described as III space loss, e.g. peritonitis, pancreatitis. Peritoneal fluid helps in the smooth gliding of intestines. Absorption of fluid and secretion of fluid are some important functions of the peritoneum.

Absorption And Exudation

This takes place through capillaries and lymphatics present in between the two layers of peritoneum. This principle is applied in dialysis. The direction of circulation is towards subdiaphragmatic lymphatics.

Protective Function

It secretes prostaglandins, interferons and free radicals which help in some protection against peritonitis.

Circulation of peritoneal fluid and its surgical importance:

• Stomata are nothing but intercellular pores over the peritoneum covering inferior surface of the diaphragm. They communicate with lymphatic pools in the diaphragm.
• During expiration, diaphragm relaxes, pores open and peritioneal fluid is drawn into stomata.
• During inspiration, diaphragm contracts, the fluid particle enter into lymphatic pools in the diaphragm and through mediastinal lymphatics propelled into thoracic duct.
• Movement of the fluid is in the cephaloid direction.
• Thus in cases of severe intraperitoneal sepsis, it is no wonder that sepsis can spread so rapidly.

Fitz-Hugh-Curtis Syndrome:

• It is exclusively seen in women/adolescent girls secondary to pelvic inflammatory disease.
• Caused by gonococci and chlamydial infections.
• Severe perihepatitis, irritation of the diaphragm, and peritonitis are features.
• Tetracycline, doxycyclines, and metronidazole are a few drugs.

Intra-Abdominal Sepsis

Intra-Abdominal Sepsis Introduction:

Intra-abdominal sepsis is one of the most challenging situations in surgery occurs due to peritonitis. The mortality ranges from 4 to 40% in Britain. It depends upon several factors which include severity of infection, experience of the surgeon, patient’s condition, comorbidity and bacterial load. They require intensive care unit with strict monitoring. An attempt has been made here to discuss common causes of sepsis and peritonitis and its management.

Peritoneal Cavity

Types of Intra-Abdominal Sepsis

• Complicated: Infection process proceeds beyond the organ into peritoneum causing localised or generalised peritonitis, e.g. perforated duodenal ulcer.
• Uncomplicated: Infection involves only one organ and does not spread into peritoneum, e.g. appendicitis in early cases.
• Infectious: Primary, secondary and tertiary peritonitis.
• Sterile.

Acute Peritonitis

Acute Peritonitis Definition:

Inflammation of the peritoneum is called peritonitis.

Acute Peritonitis Primary Peritonitis:

• Spontaneous peritonitis of childhood
• Spontaneous peritonitis of adults
• Tuberculous peritonitis
• Peritonitis associated with dialysis

Acute Peritonitis Secondary Peritonitis:

This term refers to peritonitis from an intra-abdominal source and is the most common form of peritonitis.

The following are the causes of secondary peritonitis:

1. Perforation of a hollow viscus
   • Perforated duodenal ulcer, gastric ulcer
   • Perforated enteric ulcer, tubercular ulcer
   • Perforated Meckel’s diverticulum
   • Perforated colonic ulcer
   • Ruptured appendicitis
2. Direct spread: Post-inflammatory
   • Acute cholecystitis—gangrenous

• • Acute appendicitis
  • Gangrene of the intestine
  • Acute necrotising pancreatitis

3. Penetrating injuries to the abdomen, where the organisms gain entry from outside.

4. Postoperative peritonitis is due to the introduction of infection during surgery which might be due to:

• Postoperative leaks
• Foreign body (mop) in the abdomen

5. Parturition peritonitis: It refers to peritonitis after pregnancy and delivery.

6. Blunt injuries to the abdomen: Fluid that is spilled into the peritoneal cavity (for example: Blood and bile) can travel along the paracolic gutter and manifest as pain in the right iliac fossa, causing guarding and rigidity. This has been called Valentino syndrome.

Peritoneal Cavity

Classification of Peritonitis

Primary peritonitis: Diffuse bacterial infection caused by single organism without loss of integrity of the GI tract.

Secondary peritonitis: Loss of integrity of the GI tract, multiple organism.

Tertiary peritonitis: It occurs due to recurrent infection after 48 hours—after adequate control of secondary peritonitis. A prolonged systemic inflammation is responsible leading to a higher chance of systemic inflammatory response syndrome, sepsis, severe sepsis, or septic shock. Mortality ranges between 30 and 60%.

Peritonitis Pathophysiology

• Sepsis and septic shock: Life-threatening organ dysfunction caused by dysregulated host response to infection requiring vasopressor to maintain mean arterial pressure of 65 mmHg or greater and serum lactate greater than 2 mmol/L in the absence of hypovlaemia is described as septic shock.
• Once sepsis or SIRS sets in, it results in loss of large quantity of fluids resulting in hypoperfusion. At the same time, aerobes and anaerobes act synergistically and release inflammatory mediators including toxins. Also translocation of bacteria can occur even after control of sepsis due to more oxygen delivery after control of disease. Plasma lactate or negative base excess occur resulting in acidosis. Net result is development of shock and multiorgan failure.

Peritonitis Scoring Systems

Many scoring systems are available. A few important ones are given below. They can predict survival or outcome. They are as follows.

1. The Manheim Peritonitis Index (MPI) score: It is a reliable scoring system depending upon several factors as given below. Presence of organ failure, time more than 24 hours, presence of malignancy, origin of sepsis, faecal peritonitis, generalised peritonitis.
2. SOFA score: Sequential Organ Failure Asssessment Score. The score is based on six different scores, one each for respiratory, cardiovascular, hepatic, coagulation, renal and neurological systems.
   • Factors taken into consideration are:
     • PaO2/FiO³ (mmHg), Glasgow Coma Scale, mean arterial pressure or administration of vasopressors required, bilirubin (mg/dl) [μmol/L], platelets × 10³/μl, creatinine (mg/dl) [μmol/L] (or urine output).
3. APACHE II score (Acute Physiology Age Chronic Health Evaluation–Knaus et al., 1985):
   1. AaDO² (alveolar-arterial oxygen partial pressure difference) or PaO2 (depending on FiO²)
   2. Temperature (rectal)
   3. Mean arterial pressure
   4. pH arterial
   5. These were
   6. Heart rate measured during
   7. Respiratory rate the first 24 hours
   8. Sodium (serum) after admission.
   9. Potassium (serum)
   10. The score is not
   11. Creatinine recalculated
   12. Hematocrit during the stay; it
   13. White blood cell count is by definition an
4. Glasgow Coma Scale admission score.

Acute Peritonitis Pathogenesis

Due to any one of the reasons mentioned above, infection sets in and the causative organisms multiply in the peritoneal cavity.

Gram-negative organisms: Escherichia coli (E. coli), Proteus, Klebsiella. They are present in the small and large bowel. They are the most common organisms producing peritonitis.

Enterococci: Streptococcus faecalis needs bile to grow. It is present in the urinary tract, genital tract and also in the intestines. However, both aerobic and anaerobic streptococci are the second most common organisms producing peritonitis. They are the chief organisms in puerperal sepsis.

• Bacteroides: They are anaerobic organisms, present mainly in the lower intestine.
• Bacteria from outside the alimentary canal: Gonococci, pneumococci, tubercular organisms, etc.
• These organisms proliferate in the peritoneal cavity resulting in peritonitis. A large amount of fluid gets secreted into the peritoneal cavity resulting in 3rd space loss which leads to severe hypovolaemic shock. This fluid is rich in proteins, bacteria and toxins. Due to powerful endotoxins released by gram-negative bacteria, endotoxic shock or septic shock (refer to shock), ensues.
• The fluid is rich in fibrinogen which forms fibrin and helps in the localisation of infection.
• The peritoneum loses its shiny surface, becomes reddish and oedematous and is covered with thick fibrinous exudate.
• Omentum: It is a fatty apron with rich blood supply. A mobile double-layered peritoneal fold acts like a policeman to seal the area of infection or perforation.

Examples: Perforated duodenal ulcer, acute appendicitis, acute diverticulitis, etc. Probably it also serves to supply collateral blood supply to the ischaemic viscera. In addition, it has immunological functions such as supply of phagocytes which destroy unopsonised bacteria.

Peritoneal Cavity

Types of Peritonitis

1. Local peritonitis: If a perforation is small and if it is sealed off immediately by omentum, it will give rise to local peritonitis. Examples: Small gastric ulcer perforation, diverticular perforation, gallbladder perforation. Anatomical factors also play a role in local peritonitis. Examples: Retrocaecal appendicitis with perforation. It is behind the caecum and in retroperitoneum. Signs are confined to right iliac fossa only. In posterior gastric perforations or acute pancreatitis, signs are limited to upper abdomen.

Pelvic peritonitis is another example—occur following septic abortions or salpingo-oophoritis.

2. Generalised peritonitis: If the contents of the viscus leak into the peritoneal cavity with force, as it occurs in intestinal perforation or due to perforation of a free lying organ—example: Meckel’s diverticular perforation. Virulence of bacteria is more as in colonic perforations with generalised peritonitis. Duodenal ulcer perforation can manifest as severe pain in the right iliac fossa mimicking appendicitis. Many have been mistakenly operated for appendicitis because the right paracolic gutter is board and contents travel down into right iliac fossa. This has been referred to as Valentino syndrome. Before the days of ultrasound, it used to be not uncommon to do an appendectomy in a patient who had acute pancreatitis. Inflammatory exudate gravitating along right paracolic gutter resulted in pain in right iliac fossa.

Factors Deciding the Severity of Peritonitis

• Clean perforation: Upper GI gastric juice remains sterile for 6–8 hours. Hence, in early stages, there will be mild chemical peritonitis and early treatment gives good results.
• Distal gut perforation and infected bile peritonitis: Very dangerous and severe, causing sepsis and septic shock early.
• Postoperative peritonitis that usually occurs due to anastomotic leak is also dangerous.
• A perforation sealed off early by omentum causes mild peritonitis. Retrocaecal appendicitis produces minimal local peritonitis.
• On the other hand, perforated Meckel’s diverticulitis produces diffuse peritonitis soon
• A few causes of peritonitis

Causes Of Peritonitis

Peritonitis Clinical Features

It depends upon whether it is localised peritonitis or generalised. In cases of retrocaecal appendicitis, the abdominal signs may be minimal but guarding and rigidity of the back muscles is characteristic.

Features of generalised peritonitis are as follows:

• Severe abdominal pain which is cutting in nature, becomes worse on movement of the abdominal wall. Hence, the patient lies still on the bed.
• Persistent vomiting is due to irritation of parietal peritoneum.
• The pulse rate is increased. An increase in the pulse rate may be an early indication of peritonitis, in cases of gangrene of the bowel or peritonitis following perforation of bowel.
• High-grade fever with chills and rigors indicates a septicaemic process.
• Cough tenderness indicates parietal peritoneal inflammation.
• Abdominal tenderness is elicited in all quadrants of the abdomen (Dunphy’s sign).
• Rebound tenderness (Blumberg’s sign): The abdomen is pressed for a few seconds. The patient experiences pain. Sudden release of pressure causes severe pain. It is due to sudden movement of the sensitive parietal peritoneum.

Peritoneal Cavity

• Guarding and rigidity of the abdominal wall.
• Bowel sounds are absent. Distension of the abdomen occurs within a few hours due to accumulation of fluid and paralytic ileus.
• End-stage disease: Hippocratic facies

Peritonitis Investigations

1. Complete blood picture shows high total count with predominant neutrophil count.

2. Blood examination for sugar is done to rule out diabetes mellitus. Empyema gallbladder with or without perforation can present as septic shock. Often, they are diabetic.

3. Plain X-ray of abdomen, chest and upright

• Gas under the diaphragm—perforation
• Ground glass appearance—a smooth homogeneous appearance due to the accumulation of fluid
• Air in the bowel wall—gangrene.
• Obliteration of psoas shadow and preperitoneal fat planes

4. Abdominal USG to detect fluid in the abdomen.

Following are different fluids which may give clue to the diagnosis:

• Frank pus—peritonitis of more than 48 hours old
• Bile—green coloured—duodenum, stomach, gallbladder perforation
• Faeculent—dark green coloured thick aspirate with faecal odour—ileal perforations, postoperative anastomotic leaks
• Serous—exudative—early acute pancreatitis, tuberculous peritonitis
• Haemorrhagic—haemorrhagic pancreatitis
• Food particles—hollow viscus perforation

Thus ultrasound has so many advantages even though it may not point at the specific site. However, probe tenderness with fluid in the right iliac fossa may suggest acute appendicular perforation. It may not be possible to aspirate very thick contents such as anchovy sauce pus from ruptured amoebic liver abscess but ultrasound will provide clue about the liver abscess.

5. Contrast-enhanced CT scan:

• When the signs and symptoms are equivocal, CT is the ideal investigation.
• CT can diagnose hollow viscus perforation, especially when there is no gas under the diaphragm.
• CT can detect ischaemic changes due to gangrene of the bowel-gas in the bowel wall-pneumatosis.
• CECT has higher sensitivity and specificity but it has radiation exposer of almost 200 chest X-rays.
• CT can diagnose unsuspected and unexpected lesions in the abdomen including diverticular perforations, internal herniation and gangrene, acute pancreatitis, etc.
• Adequate hydration and normal renal function (as indicated by normal creatinine values) are important before a contrast-enhanced CT scan.

6. Abdominal tap:

• Aspiration of blood indicates haemoperitoneum or gangrene of the bowel.
• Aspiration of bile indicates biliary peritonitis due to perforation of duodenal ulcer, gallbladder or intestine.
• Aspiration of frank pus indicates peritonitis due to gram-negative bacteria. Foul-smelling pus is due to anaerobic bacteria producing free fatty acids and their esters. Always send the fluid for culture sensitivity.
• Amylase estimation should be done to rule out pancreatitis.

Peritoneal Cavity

7. MRI: It is costly, may not be available all the time.

Indicated in pregnant patients with abdominal pain and ultrasound is inconclusive.

8. Diagnostic laparoscopy can be used in suspected cases of peritonitis (Key Box 45.6). When in doubt, do laparoscopy: It can reveal ‘hidden’ pathology.

Peritonitis Treatment

1. Aspiration: Nasogastric aspiration with Ryle’s tube helps in decreasing gastrointestinal secretion. Thus it reduces abdominal distension. It also prevents vomiting and gives rest to the gut. Indirectly, it reduces ‘bacterial load’ contaminating peritoneum.

2. Bowel care and blood: Purgatives should not be given as it may result in perforation. Blood is arranged for surgery.

3. Charts: Temperature, pulse rate, respiratory rate, intake-output charts are maintained.

4. Drugs are given against gram-positive, gramnegative and anaerobic organisms.

5. Exploratory laparotomy and appropriate surgery is done followed by thorough peritoneal toilet/wash with normal saline.

6. Fluids: IV fluids are given before, during and after surgery. Central venous cannulation and measurement of central venous pressure (CVP) is indicated in unstable patients to guide fluid therapy. If not possible, an emergency cut down (venesection)— cephalic or basilic vein, is done followed by fluid infusion. Preoperatively, the aim is to maintain at least 30 ml/hr of urine output.

• Ringer lactate solution is an ideal replacement.

Principles of Surgery for Peritonitis

1. Adequate incision is used—upper/mid/lower midline.

2. As soon as the peritoneal cavity is opened, purulent fluid comes out. The fluid is collected and sent for culture and sensitivity. Greenish fluid indicates a hollow viscus perforation. All the fluid is drained the source of peritonitis is identified and appropriate surgical procedure is done.

Examples are:

• Appendicectomy for appendicitis.
• Closure of perforation for perforated peptic ulcer.
• Closure or resection for ileal perforation.
• Resection of the bowel for gangrene.

Control of sepsis: This is the most important step of treatment of peritonitis. Removal of septic focus is a primary aim—examples: Appendicectomy, perforation closures (duodenal ulcer) or resection (intestinal or colonic perforation) or cholecystostomy in difficult perforated gallbladder diseases. However, all the septic foci in the abdomen have to be removed— necrotic material, pus pockets and food particles.

Thorough irrigation with warm saline cleans up subhepatic spaces, pelvic spaces and interloop collections. Primary anastomosis in presence of sepsis may result in leak and postoperative peritonitis. It is better to do colostomy or ileostomy in such cases. Incision can be partially closed leaving the skin open—sutures can be tied after 2 days in the ward.

3. It is better to use nonabsorbable suture material such as silk for intestinal anastomosis or for closure of perforation. In the presence of infection, absorbable sutures, such as catgut, get absorbed very fast.

4. A thorough peritoneal wash/lavage is given by using warm saline (up to 3–5 litres) to avoid intraperitoneal abscesses. Antiseptic agent such as betadine solution should be avoided because they can cause adhesions.

5. The peritoneal cavity is drained to the exterior by using tube drains. These are kept in the subhepatic space and in the pelvic cavity.

6. The wound is irrigated with antiseptic agents.

7. Tension sutures are put in depending on the severity of the peritonitis to prevent burst abdomen.

8. Laparostomy (vide infra): This method of exposing the peritoneal cavity can be done in selected cases if abdominal compartment syndrome is suspected.

Nutrition in sepsis:

• Sepsis is a catabolic event.
• Cytokines and TNF, insulin resistance play a role.
• Glucose is an essential part of nutrition and should amount to at least 500 kcal per day.
• Glucose gets converted to carbon dioxide and when in excess, can increase respiratory load.
• To reduce this, 50% daily energy requirements can be provided using lipids.
• Proteins should also be provided, bearing in mind, the increased protein catabolism in sepsis.

Nutrition in sepsis Laparostomy

This refers to leaving peritoneal cavity exposed to outside without approximation of the anterior abdominal wall. Some situations arise, especially in emergency cases, where this is required. Hence, it is important to know how to deal with this situation.

Nutrition In Sepsis Types

1. Open laparostomy: Abdominal fascia and peritoneum are not sutured.

• Open laparotomy Advantages: Abdominal compartment syndrome can be prevented. Details are given later.
• Open laparotomy Disadvantages: Significant fluid loss and secondary infection

2. Closed laparostomy or mesh laparostomy: Here the fascial layer is closed by using marlex mesh or prolene mesh or even a zip to protect exposed viscera.

• Closed laparotomy Advantages: One can minimise infection.
• Closed laparotomy Disadvantages: Abdominal compartment syndrome and perforation of bowel can occur.

Indications of Laparostomy:

When a second look procedure is contemplated, e.g. acute pancreatitis, mesenteric ischaemia.

Nonoperative Treatment of Peritonitis

1. Too sick a patient to tolerate the surgical procedure.
2. Sealed perforation
3. Localised peritonitis—may resolve with treatment.

Abdominal Compartment Syndrome

Abdominal Syndrome Introduction

The phrase “abdominal compartment syndrome” was coined in 1984 when Irving Kron, described the measurement of intra-abdominal pressure as a means of developing criteria for abdominal decompression to improve organ function.

Abdominal Syndrome Definition

• Abdominal compartment syndrome (ACS) is defined as a sustained increase in IAP more than 20 mmHg with or without an abdominal perfusion pressure (APP) < 60 mmHg)] that is associated with new organ dysfunction/failure.
• Intra-abdominal pressure (IAP) is the pressure concealed within the abdominal cavity. Normal IAP is 0–5 mmHg showing phasic variation with respiration.
• Intra-abdominal pressure is measured to detect abdominal compartment syndrome and to decide on the requirement of a decompression so as to improve organ function.

Abdominal Syndrome Final Effects

The adverse physiological effects of intra-abdominal hypertension (IAH) affect almost every organ system resulting in ACS.

The major systems affected, in decreasing frequency of incidence and morbidity are:

Pulmonary, cardiovascular, renal, splanchnic, central nervous system.

Thus, the end result can be:

• Intractable hypoxia, hypercarbia, ARDS
• Cardiac insufficiency and cardiac arrest
• Oliguria, anuria, acute renal failure
• Cerebral oedema and anoxia

Grading of IAP (Burch)

• Grade 1 : IAP 12–15 mmHg
• Grade 2 : IAP 16–20 mmHg
• Grade 3 : IAP 21–25 mmHg
• Grade 4 : IAP >25 mmHg

Abdominal Compartment Syndrome Risk Factors

1. Diminished abdominal wall compliance:

• Acute respiratory failure with elevated intrathoracic pressure.
• Abdominal surgery with primary fascial or tight closure. Example: Reduction of massive hernia
• Major trauma/burns
• Prone positioning, head of bed >30°
• High BMI, central obesity

2. Increased intraluminal contents:

• Gastroparesis
• Acute gastric dilatation
• Ileus
• Colonic pseudo-obstruction

3. Increased abdominal contents:

• Haemoperitoneum/pneumoperitoneum
• Ascites/liver dysfunction
• Laparoscopy

IAP Measurement—Principles

• Expressed in mmHg (1 mmHg = 1.36 cm H₂O).
• Measured at end expiration
• Performed in supine position
• Zeroed at mid-axillary line at the level of iliac crest.
• Performed with an instillation volume of no greater than 25 ml of saline (for bladder technique).
• Measured 30–60 sec after to allow bladder detrusor muscle relaxation (for bladder technique).

Abdominal Syndrome Medical Treatment

• Close monitoring of patient’s vitals
• Blood transfusion when required
• Nutritional supplements—intravenous/TPN

Abdominal Syndrome Surgery

1. Temporary Abdominal Closure:

• Towel clip closure, only skin closure.
• Mesh—commercially available meshes with absorbable surface facing intraperitoneum and nonabsorbable surface facing outer aspect of the wound are used. Example: Mesh with polyglactin (vicryl) inside and polopropylene (prolene) outside can be used.
• PTFE mesh repair: Expanded polytetrafluoroethylene (ePTFE) is another mesh which is used. It is a surgical biomaterial with two antimicrobial preservative agents—chlorhexidine diacetate and silver carbonate. It also enhances tissue ingrowth.
• Bogota bag: A Bogota bag is a sterile plastic bag used for closure of abdominal wounds.1 It is generally a sterilised, 3-litre genitourinary irrigation bag that is sutured to the skin or fascia of the anterior abdominal wall. The Bogota bag acts as a hermetic barrier that avoids evisceration and loss of fluids. Another advantage to the Bogota bag is that the abdominal contents can be visually inspected which is particularly useful in cases of ischaemic bowel. Thus, it is useful in resections following mesenteric ischaemia. In our country, we can use urosac bag (which can be split open) or even a thin plastic sheet can be used like a Bogota bag.

A young boy of 18 years, who suddenly had breathlessness was found to have a diaphragmatic hernia. After reduction and closure, patient developed ACS. Reopening of abdomen was done and peritoneum was not closed but a ‘cover’ was given by using ‘urosac’ bag which was split open. Wound was allowed to heal by granulation tissue.

• Vacuum-assisted closure (VAC): It has been extensively used in the management of leg ulcers especially diabetic ulcers. It has been used in a few cases of severe pancreatitis. Here it is called open abdomen negative pressure therapy system. It removes debris, and inflammatory exudates.

2. Definitive Abdominal Closure:

• Primary closure. It is done layer by layer. The nonabsorbable suture is usually selected.
• Synthetic mesh
• Biologic mesh
• Component separation
• Plastic surgery

Complications Of Peritonitis

1. Severe hypovolaemic shock gives rise to renal failure. It can be prevented by adequate hydration of the patients and careful usage of antibiotics such as gentamicin.
2. Septic shock, multiorgan failure and death occur in late cases of peritonitis.
3. Subacute intestinal obstruction due to postoperative adhesions. They are easily separable adhesions.
4. Pelvic abscess
5. Subphrenic abscess

Pelvic Abscess

This refers to accumulation of pus in the rectovesical pouch or pouch of Douglas (rectouterine pouch).

Pelvic Abscess Causes

• Any peritonitis, commonly following perforation due to acute appendicitis or following salpingooophoritis can result in pelvic abscess. The rectovesical pouch is the most dependent part in the body. Hence, the septic emboli accumulated in peritoneal space give rise to pelvic abscess.
• Anastomotic leakage is also an important cause.
• Perforated duodenal ulcer, perforated ileal ulcers are the other common causes.

Pelvic Abscess Clinical Features

• History of surgery/peritonitis
• Postoperative high-grade fever
• History of discharge of mucus per rectum for the first time in a patient who is recovering from peritonitis suggests pelvic abscess. It occurs due to irritation of the rectum. Increased frequency of micturition occurs due to irritation of bladder.
• Deep tenderness in the suprapubic region.
• Continuing infection even after surgery—leak from an anastomotic line.
• Inadequate peritoneal toilet at the time of first surgery
• Inappropriate antibiotics.

Pelvic Abscess Diagnosis

• Confirmed by per-rectal examination. A tender boggy swelling is felt in the anterior wall of the rectum.
• Ultrasound can define an abscess and can detect the size of the abscess.
• CT scan is very useful in defining pelvic abscess, its extent and detecting the presence of a foreign body.

Pelvic Abscess Treatment:

• Under general anaesthesia, a proctoscope is introduced and a nick is made in the anterior wall of the rectum to open into the abscess cavity. The pus is drained with sinus forceps through the rectum. There is no peritoneal contamination. The cavity collapses after a few days. Postoperatively, the patient is given broad-spectrum antibiotics.

• In females, pus can be drained through posterior fornix.

A 36-year-old lady underwent vaginal hysterectomy for dysfunctional uterine bleeding. To control the bleeders, several gauze pieces were used without a proper count.

After 2 weeks, purulent discharge per vagina, fever, ill health were reported. Ultrasound showed a pelvic abscess. CT scan done in our hospital showed foreign body with air trap suggesting gauze pieces. Her abdomen was explored, abscess drained and the gauze pieces were removed.

Subphrenic Abscess

Subphrenic Abscess Introduction

• As a result of peritonitis, residual abscess can collect in the intraperitoneal cavity. Pus that collects under the diaphragm is described as subphrenic abscess.
• Subphrenic abscess is the commonest intra-abdominal abscess.
• Gastrointestinal perforations, postoperative leaks, penetrations, trauma and puerperal sepsis are the common causes of subphrenic abscess.
• Blood clots, bacteria laden fibrin and neutrophils contribute to an abscess.

Surgical Anatomy

There are five subphrenic spaces between the diaphragm and the liver bounded by various peritoneal folds. Four are intraperitoneal and one is extraperitoneal. The spaces, boundaries and the common causes of pus in these spaces are described.

Aetiopathogenesis

• The causative organisms of peritonitis are Escherichia coli, enterococci, Klebsiella, Enterobacter, Proteus, Bacteroides, etc.
• The high incidence of subdiaphragmatic abscess is due to constant circulation of fluid from below upwards because of the following reasons:
  • Upward movement of diaphragm during expiration.
  • Decreased intra-abdominal pressure
  • Capillary action

Subphrenic spaces, boundaries and common causes of involvement:

A subphrenic abscess is common on the right side because of the following reasons:

1. The right paracolic gutter is wide and deep and colophrenic ligament is absent.
2. The left paracolic gutter is narrow and colophrenic ligament is present on the left side.
3. The majority of diseases affect right side (perforation, liver abscess, appendicitis, gallbladder disorders, etc.).

Subphrenic Abscess Clinical Features

• A patient who is recovering from peritonitis complains of fever with sweating. Initially, the fever is low grade, continuous. Later, there is a high-grade fever with chills and rigors.
• Deterioration of health occurs very fast with wasting and anorexia.
• Shoulder pain is due to irritation of undersurface of the diaphragm by the pus (sensory fibres of the phrenic nerve are irritated—C3, C4).
• The postoperative patient is not doing well—prolonged ileus.
• Anorexia, wasting, hiccup, dry cough.

A postoperative patient who has pyrexia, prolonged ileus, poor appetite and progressive deterioration of health has subphrenic abscess.

• Tenderness is present in the epigastrium on deep palpation.
• Common causes of postoperative fever are absent, e.g. thrombophlebitis, urinary tract infection.

Pus nowhere, pus somewhere, pus under the diaphragm— Harold Barnard.

Subphrenic Abscess Investigations

1. Total count with neutrophil count.

2. A plain X-ray of abdomen (erect)—may show gas and fluid level under the diaphragm.

3. Fluorescent radiography may reveal absence of movement of right side of diaphragm on inspiration.

4. Ultrasonography confirms the site of abscess, number of abscesses, loculations, etc.

• Abscess is characterised by hypoechogenic cavity surrounded by sharp distinct echogenic wall. It can be therapeutic to insert catheter for drainage.

5. CT scan demonstrates well defined, low density mass, the rim of which is enhanced after intravenous injection of contrast medium. The mass tends to be round because of centripetal expansion—high sensitivity >95%.

6. Isotope imaging using Gallium 67 citrate or Iridium Gallium binds to proteins—lactoferrin and transferrin which are present in high concentration in an abscess.

Subphrenic Abscess Treatment

Today with the availability of sophisticated imaging facilities, percutaneous drainage has become the choice of therapy rather than surgery. Both have been described in the next column.

1. Percutaneous Drainage:

It can be done with the help of ultrasound or CT scan, provided the abscess cavity is unilocular, and the track is safe.

Percutaneous Drainage Types:

• Pigtail catheter (using Seldinger’s technique): It is a small tube used to drain bile, urine, pancreatic fluid or abscess.
• Trocar catheter: 12–16 F trocar is used.
• Sump catheter: It has a double lumen which permits irrigation as well as drainage and allows a good suction.

More than 90% of subphrenic abscesses are managed by percutaneous drainage successfully.

2. Laparoscopic Drainage:

With imaging, the majority of subphrenic abscesses are treated by the laparoscopic method. It is not only minimally invasive but can drain all cavities, open loculi and a thorough lavage can be given. If any foreign body is present, it can be removed. However, if adhesions are present, damage to the intestine can occur.

3. Open Drainage:

• The anterior subcostal or posterior (bed of 12th rib) approach is used. Both are extraserous approaches.
• However, lesser sac abscess and abscesses connected with the bowel, discharging pus or bile, are drained by intraperitoneal route.
• Open drainage is ideal in cases of multiloculated abscesses.
• Surgery is always done under the cover of broadspectrum antibiotics.

Special Types Of Peritonitis

Postoperative Peritonitis Introduction

This is not an uncommon problem encountered in the surgical wards. Often this is a patient who has undergone intestinal or biliary surgery and a few days later, develops vague symptoms and signs. It is difficult to diagnose, if one takes a casual approach. It has high mortality. Hence, it requires early detection, and demands early and effective solution.

It should be suspected following surgery on intestines or biliary tract, when a patient who is recovering from paralytic ileus starts deteriorating or when paralytic ileus does not return back to normal.

Postoperative Peritonitis Aetiology:

• Leakage from anastomotic line—most common
• Iatrogenic visceral trauma
• Foreign bodies
• Others

Causes of Delay In The Diagnosis:

• The presence of fever is attributed to other sources of infection such as urinary tract infection, thrombophlebitis, etc.
• The presence of pain and tenderness is attributed to recent laparotomy scar.
• Tachypnoea and hypotension are attributed to preexisting medical conditions, such as COPD, cardiac failure.
• Steroid therapy masks the local signs and symptoms.
• Administration of antibiotics would have reduced the severity of peritonitis (masking effect) only to manifest as septicaemia some time later.

Postoperative Peritonitis Bacteriology:

How to Suspect Postoperative Peritonitis:

• A patient who is recovering from initial laparotomy complains of abdominal pain and distension. He is not well. Has fever.

• Tenderness is a feature.
• Deterioration after 3–5 days of operation (the time when anastomotic dehiscence takes place).
• Delay in recovery from paralytic ileus—abdominal distension.
• Evidence of toxaemia—tachycardia, tachypnoea.
• Free drainage of bile and faecal matter or pus from the drain site or the main wound.
• Oliguria may be an early indicator of postoperative sepsis.
• Guarding, rigidity may be present but minimal.

Treatment of Postoperative Peritonitis

1. Anastomotic leak: The majority of the cases are due to anastomotic leak.

• Wait and watch policy is done, if contents are coming out freely and patient is haemodynamically stable, no tachycardia, no tachypnoea, no hypotension.
• CECT of abdomen is done to rule out fistula tract/ communication/foreign bodies, etc.
• However, if patient deteriorates, he is subjected to exploratory laparotomy and treated depending upon the findings at laparotomy.
• Examples: If a leak is detected from duodenal ulcer perforation closure site, re-suture it. Then add feeding jejunostomy and drain peritoneal cavity.
• If right hemicolectomy has leaked, explore, trim the edges, suture healthy tissue and do a protective proximal ileostomy.
• If a colocolic anastomosis has leaked, redo the anastomosis, with or without proximal stoma.

2. Prevention of gossypiboma (MOP):

• Double counting
• Sponges with radio-opaque markers
• No hurried counting
• Additional counting—when change of OT personnel
• Avoid using packs—fascial closure
• Intraoperative radiology
• High degree of suspicion (see clinical notes)

3. Specific treatment:

In 1973, when ultrasound facilities were not available, a 35-year-old male who had undergone appendicectomy for a gangrenous appendix, was found to have high spiking fever on the 3rd postoperative day. All possible causes of postoperative fever including malaria were ruled out. On the 10th postoperative day, the patient developed a purulent discharge of 100 ml through the lower part of the main wound following which he had a spontaneous and dramatic recovery.

Poor Prognostic Factors in Postoperative Peritonitis

• Increasing age
• Organ(s) failure
• Colonic perforation
• Multiple abscess
• Lesser sac abscess
• Malnutrition
• Postoperative pneumonia
• Anergy: It (immunologic tolerance) refers to the failure to mount a full immune response against a target.

Biliary Peritonitis

Leakage of bile into the peritoneal cavity results in biliary peritonitis.

It will be more obvious and can be detected early, if a drainage tube has been kept.

Biliary Peritonitis Causes

1. Surgery on the gallbladder:

• Leakage from the cystic duct
• Injury to the right hepatic duct
• Leak from accessory cholecystohepatic duct

2. Surgery on the CBD:

• Retained stones in the lower CBD (postoperative)
• Loose sutures over CBD
• T-tube not anchored properly

3. Surgery on the duodenum:

• Sphincteroplasty
• Partial gastrectomy
• Perforation of sutured duodenal ulcer

4. Injury to the duodenum:

• During nephrectomy, hemicolectomy
• Blunt injury

5. Instrumentation: ERCP, stenting or following duodenal polypectomy.

6. Diseases of the gallbladder: Perforation or gangrene of the gallbladder.

Biliary Peritonitis Clinical Features

• In the majority of the cases, the local signs are confined to one quadrant of the abdomen in the form of guarding and rigidity.
• There may be excoriation of the skin due to drainage of bile to the exterior.
• However, when the anastomosis gives way, generalised peritonitis can occur.
• In untreated cases, septicaemic shock can develop.
• Final stage will be multiorgan failure and death.
• It has a very high mortality rate.

Biliary Peritonitis Treatment

1. Most of the biliary fistulae heal within 2–3 weeks with conservative line of treatment.
2. If it does not heal, re-exploration and resuturing or resection has to be done.
3. Feeding jejunostomy is a very useful procedure in all cases of reperforation of sutured duodenal ulcers or difficult duodenal ulcer closures.

It should be remembered that feeding jejunostomy is temporary and is kept till it is assured that there is no leak from the operated site. If there is no peritonitis, the patient has passed flatus and stools, the jejunostomy tube is removed.

Feeding jejunostomy should be done carefully with proper placement of catheter within the small bowel, fixing it firmly both inside and outside the abdominal wall and fixing to the bowel wall.

Complications of feeding jejunostomy:

• Bile leaks from the entry point.
• Tube blockage, if it is not flushed properly after feeding.
• Bleeding, displacement and intussusception.

Pneumococcal Peritonitis

• Primary variety is more common. Girls of 3–6 years of age are usually affected. The infection spreads from the female genital tract through the vagina.
• Malnourishment precipitates pneumococcal peritonitis.
• In boys, blood spread can occur following an upper respiratory tract infection.

Biliary Peritonitis Clinical Features

• High-grade fever with features of toxaemia.
• Bloody diarrhoea and frequency of micturition are indicative of pelvic peritoneal inflammation.
• Other features of peritonitis are present.

Biliary Peritonitis Diagnosis

Aspiration of peritoneal fluid demonstrates a high WBC count—30,000/mm3. More than 90% are polymorphs.

Biliary Peritonitis Treatment

Laparotomy and drainage of pus (odourless and sticky initially and creamy or purulent in the later stages), to be followed by appropriate antibiotics.

Primary Streptococcal Peritonitis

• Infants and children less than 4 years are commonly affected.
• Peritoneal exudate is cloudy and contains flakes of fibrin.
• Symptoms of gastroenteritis—greenish watery stools are present.
• Source of infection is tonsillitis, pharyngitis, etc.
• Treated with injection crystalline penicillin.

Parturition Peritonitis

• This occurs after delivery, if proper aseptic precautions are not taken. The incidence has come down in the recent years. Attempted abortions by using instruments which are not sterile results in peritonitis. Most of the time, peritonitis is confined to pelvis with paralytic ileus, mucous diarrhoea and offensive lochia Late cases develop generalised peritonitis, intraabdominal abscess, intestinal obstruction and infertility. Table 45.2 gives summary of various types of peritonitis.
• Other name for this type of peritonitis is abortion peritonitis.

Spontaneous Bacterial Peritonitis (SBP)

As the name suggests, in this condition, there is no demonstrable intra-abdominal disease responsible for peritonitis, such as perforation, abscess, gangrene, etc.

Spontaneous Bacterial Peritonitis  Types

1. In infants: It is more common in female children. Spread is by haematogenous route. The causative organisms are Streptococcus pneumoniae. It may follow respiratory tract or urinary tract infection.

2. In adults: Male alcoholic patients are commonly affected followed by patients with chronic liver disease. Causative organisms are E. coli, S. faecalis, etc.

• Portal hypertension increases permeability of gut wall, thus increasing bacterial migration. These bacteria which colonise in the small bowel reach systemic circulation because of shunting of blood around liver sinusoids. Portal lymph also gets contaminated giving rise to increased ascitic fluid. So, this is translocation of bacteria.

Summary of various types of peritonitis:

• It is interesting to note that it is rare for anaerobic microorganism to produce SBP. Due to high volume of oxygen in the intestinal wall, they cannot translocate.

Spontaneous Bacterial Peritonitis  Clinical Features

• Dull aching pain in the abdomen with low-grade fever.
• Rebound tenderness is present, bowel sounds are absent or sluggish—abdominal distension.
• Cirrhotic patients may develop coma with onset of primary bacterial peritonitis.
• Septic shock is a late feature with a high mortality rate.

Spontaneous Bacterial Peritonitis  Investigations

• Leucocytosis, ↓albumin, ↑prothrombin time suggests sepsis.
• Peritoneal tap and Gram staining of the fluid.
• The diagnosis of SBP is made when ascitic fluid contains more than 250 neutrophils/mm3. Ascitic fluid also has low protein.
• Ascitic fluid culture is usually monomicrobial.
• Laparoscopy may help to rule out intra-abdominal emergencies, such as perforations, etc.
• Ultrasound can detect nature of the liver and amount of fluid in the abdomen.
• CT scan when in doubt about the diagnosis.

Spontaneous Bacterial Peritonitis  Treatment

• Conservative treatment is followed, provided secondary bacterial peritonitis is ruled out.
• Broad-spectrum antibiotics, such as aminoglycosides with 3rd generation cephalosporins are the ideal choice. Metronidazole can also be added.
• Installation of antibiotic solution into ascitic fluid to achieve a quick and high concentration.
• If laparotomy is done, peritoneal wash or toilet is given.

Periodic Peritonitis

• Also called familial Mediterranean fever.
• It is of unknown aetiology.
• It affects children, young adults and females.
• Presents as abdominal pain, tenderness, pyrexia and increased total WBC count.
• When in doubt, laparotomy should be done.

Tumours Of The Peritoneum

• Primary: Mesothelioma is the tumour to be remembered. It is more common from the pleura. In the abdomen, pelvic peritoneum is the common site.
• Secondary tumours are—pseudomyxoma peritonei and carcinoma peritonei.

Pseudomyxoma Peritonei

• In this condition, peritoneal cavity is filled with mucoid substance (jelly-like) brownish or yellowish.
• Mucinous adenocarcinoma of the ovary is the cause.
• The primary tumour is very slow growing and metastasis is exceptional.
• Ruptured mucinous adenocarcinoma appendix and/ or ovarian adenocarcinoma are the causes.
• Once rupture takes place, peritoneal cavity is studded with jelly-like mucous-secreting tumours which appear as large loculated cystic masses.
• From the appendix, it can be benignmucinoma of appendix to mucinous adenocarcinomas.

Tumours Of The Peritoneum Clinical Features

•  Age group: 40–50 years. Equal incidence in both sexes.
• The patients can present with slow, painless and progressive abdominal distension. No shifting dullness.
• A few patients present with features of intestinal obstruction.
• Recurrence can occur because the tumour is locally malignant.

Tumours Of The Peritoneum Investigations

CECT of abdomen/pelvis is done to get details about any previous pathology in the appendix or ovary.

Tumours Of The Peritoneum Treatment

• Remove as much as possible (debulking). This is described as cytoreduction.
• Appendicectomy, omentectomy, peritonectomy.
• Reject the involved organs (adjacent to tumours) may be colon, small bowel, etc.
• Hyperthermic intraperitoneal chemotherapy(HIPEC)

Carcinoma Peritonei

This name is applied to an advanced stage of intraabdominal malignancy involving the entire peritoneal cavity.

Carcinomas of the stomach, colon, pancreas, breast and ovary are the common causes.

Features at Laparotomy:

• Multiple firm to hard nodules on the visceral and parietal peritoneum.
• Dense adhesions between the intestinal loops and other viscera.
• Plaques on the intestinal surface
• Widespread secondaries in the liver
• The entire omentum will be studded with hard nodules.
• It is called omentum cake.
• Ascites: Straw-coloured or haemorrhagic
• Greater omentum being the policeman and a great drain pipe of the abdomen with rich lymphatics, is studded with nodules.
• Low protein ascites is more vulnerable for risk of developing peritonitis. Incidence of peritonitis in malignant ascites cases is low because of increased immunoglobulin levels in malignant ascites and increased opsonic activity.

Tumours Of The Peritoneum Differential Diagnosis:

• The most common differential diagnosis is tuberculosis (peritoneal). These nodules are firm and greyish.
• Acute pancreatitis with fat necrosis: This is due to calcium soap. They are yellow and soft.
• Ruptured hydatid cyst
• Lymphomatous nodules
• Ruptured GIST

Tumours Of The Peritoneum Treatment:

1. Radioactive gold (198Au) instillation into peritoneal cavity.
2. Tamoxifen is useful for ascites due to carcinoma of the breast.

Granulomatous Peritonitis

• Talc, gauze, starch, etc. are causative factors.
• It occurs many weeks after surgery.

• Low-grade fever, weight loss, distension, crampy abdominal pain are the features.
• Laparoscopy is the key investigation. One can visualise granuloma and biopsy can be taken. Also, fluid can be aspirated and sent for histopathology. High concentrations of lymphocytes are present in both.
• Symptomatic treatment—sinus, fistula needs to be treated.
• Intravenous prednisolone followed by oral prednisolone for 2–3 weeks is given.

Granulomatous Peritonitis Prevention

• Cleaning the gloves by wiping before handling bowel, prevents many cases of granulomatous peritonitis.
• In the initial surgery, all the foreign bodies including ova, cysts of parasites, ascariasis and ingested food particles have to be removed.

The Omentum

Surgically important diseases in the omentum are:

1. Tuberculous peritonitis: Here omentum is involved.

It becomes nodular because it is studded with tubercles. Classically seen in children who are brought with abdominal distension. On palpation, omentum is felt as granular mass in the upper abdomen which moves with respiration. Laparoscopy, biopsy and antitubercular treatment.

2. Metastasis: Carcinoma stomach, colon, pancreas commonly result in metastasis and they give rise to omental cake.

3. Tumour (cyst): Omentum is the site of omental cyst which is a lymphatic cyst. It is a slow growing, painless swelling in the upper abdomen.

On examination, the patient is a child or an adult, with a smooth, firm mass in epigastrium which moves with respiration. Excision of the lymphatic cyst is the treatment. Massive cyst can be confused for ascites.

4. Torsion: It is a rare surgical emergency wherein torsion of omentum occurs due to old adhesions or it is primary due to lengthy mobile omentum. It produces symptoms/signs similar to that of appendicitis. Laparotomy and excision of gangrenous omentum have to be done.

5. Non-Hodgkin’s lymphoma can affect ometum and can give rise to granularity.

Complications: Haemorrhage into the cyst.

Mesentery

Anatomy:

• Mesenteric tear has been discussed.
• Mesenteric lymphadenitis has been discussed.

Misty Mesentery

• It means increase in the mesenteric fat and it is a finding in the multi-detector CT scan.
• A few pathological conditions which may give rise to this entity are: Acute pancreatitis, retroperitoneal haemorrhage, malignancies.
• Once the source is treated, the findings may reduce or may disappear.
• Hence, follow-up CT scans are required.
• Weber-Christian disease: Lipodystrophy and mesenteric lipogranuloma are the features. In this condition, it should be called mesenteric panniculitis. Findings include inflammation of the mesentery, fibrosis, shortening and ischaemia. It is difficult to treat.
• Pathology, clinical features, differential diagnosis, investigations and management of mesenteric cyst.

These are congenital cysts, enterogenous or chylolymphatic. It manifests in young children or during adolescence. Typically, the cyst is located in the umbilical region which moves at right angles to the direction of mesentery.

Types of Mesenteric Cysts:

1. A chylolymphatic cyst is a lymphatic cyst arising from mesentery of ileum. It is a thin-walled cyst with clear fluid or chyle. It has a separate blood supply. Hence, enucleation is the treatment without sacrificing the bowel.

2. Enterogenous cyst is a duplication cyst from the intestine or due to diverticulum of the mesenteric border of the intestine. It is thick walled and contains mucus. This cyst is treated by excision of cyst with bowel segment because both share the same blood supply.

Mesentery Complications:

• Torsion of the cyst results in acute abdominal pain.
• Rupture of the cyst due to trauma
• Haemorrhage into the cyst

Retroperitoneum Anatomy:

Retroperitoneal space: The retroperitoneal space lies between the peritoneum and the posterior parietal wall of the abdominal cavity and extends from the diaphragm to the pelvic floor.

• Superiorly—12th thoracic vertebra and lateral lumbocostal arch.
• Inferiorly—base of the sacrum, iliac crest, and iliolumbar ligament.
• Anteriorly—posterior parietal peritoneum.
• Posteriorly—fascia overlying the quadratus lumborum and psoas major muscles.

Important Anatomical Organs:

1. Urinary: Adrenal glands, kidneys, ureter, bladder

2. Circulatory: Aorta, inferior vena cava

3. Digestive: Oesophagus (thoracic part), rectum (part of the middle third and lower third is extraperitoneal).

4. The head, neck, and body of the pancreas, the duodenum, except for the proximal first segment, ascending and descending portions of the colon.

Idiopathic  Retroperitoneal Fibrosis-Ormonds Disease

• This is one of a group of fibromatosis (the other being Dupuytren’s contracture and Peyronie’s disease).
• Other types of fibrosis such as mediastinal fibrosis, and sclerosing cholangitis may also be associated features.
• Riedel’s thyroiditis may be associated with this condition.
• As collagen encases ureters, they present with ureteric obstructions, requiring ureteric stenting.
• Steroid therapy is the treatment of choice.
• Tamoxifen may help.
• It can present with lower back pain, renal failure, hypertension, deep vein thrombosis and other obstructive features.

Retroperitoneal Cyst

• Very often, it is a painless, smooth, firm enlargement.
• May have a minor degree of mobility.
• These cysts are either lymphatic cysts or derived from the remnant of the Wolffian duct. A few of them are teratomatous dermoids.
• Benign retroperitoneal cysts are usually mesothelial or mesonephric in origin; rarely, rupture of the biliary tree can result in bile-filled cysts.
• Gross: These cysts are not connected to the kidney or adrenal; usually filled with clear or straw-coloured fluid.
• Histology: These cystic structures may be lined by mesothelial, enteric (glandular), or columnar epithelium.
• They can be unilocular or multilocular.
• CT scan is required to differentiate it from hydronephrosis.
• Excision is the treatment.

Retroperitoneal Abscess

Retroperitoneal Abscess Causes:

1. Renal source: Pyonephric abscess
2. Spine: Tuberculosis (details below)
3. Haematoma: Fracture of spine/pelvis
4. Acute pancreatitis (on the right side)
5. Retrocaecal appendicitis (on right side)
6. Sigmoid diverticulitis

Retroperitoneal Abscess Diagnosis:

• Ultrasound or CT scan-guided aspiration
• Culture of the pus and antibiotic sensitivity.

Retroperitoneal Abscess Treatment:

Aspiration, appropriate antibiotics and open drainage.

Psoas Abscess

Three types have been recognised:

1. Primary psoas abscess: It is caused by haematogenous spread of Staphylococcus aureus. Source may be occult—tonsils, middle ear, etc. More common in children and young adults. Poor nutrition, may be a contributing factor—it is monomicrobial.

2. Secondary psoas abscess: Secondary to intestinal perforation, e.g. Crohn’s disease. It is polymicrobial. Other causes are diverticular perforation, acute pancreatitis, etc.

Psoas Abscess Clinical features:

Fever, flank pain, and flexion of the hip joint are triad of psoas abscess. Pain on extension confirms the diagnosis.

Psoas Abscess Management:

• CT scan is the diagnostic test. Gas bubbles are diagnostic of an abscess.
• Treatment include percutaneous catheter drainage, treatment of the source of infection with antibiotics.
• If necrotic tissue does not drain well or if patient is not improving, open drainage should be done.

3. Tuberculous spine: Lower thoracic (T10) and upper lumbar spine are commonly affected.

Psoas Abscess Clinical Features:

• Pain in the back (localised to lesion) or referred pain, if there is a collapse.

• Evening pyrexia
• Protective muscular spasm, especially of sacrospinalis.
• Collapse of the anterior portion of vertebral body results in angular deformity—gibbus.

Route of Psoas Abscess:

• Pus enters psoas sheath and tracks downwards and causes mass in the iliac fossa.
• From here, it traverses beneath inguinal ligament.
• If untreated, it collects in the subcutaneous plane.

Psoas Abscess Investigations:

• Chest X-ray, ESR, sputum AFB
• Spine X-ray—AP and lateral view. The earliest sign is a decrease in the intervertebral space.
• MRI can detect spine lesion, cold abscess
• CT/MR-guided aspiration of pus/biopsy to prove histological diagnosis.

Psoas Abscess Treatment:

• Cold abscess—aspiration followed by antituberculous treatment.
• Unstable/collapse spine—costotransversectomy— lateral thoracotomy.

Retroperitoneal Tumour

Retroperitoneal Tumour Definition:

The term retroperitoneal tumour (RPT) is usually confined to primary tumours arising in other tissues in this region, e.g. muscle, fat, lymph nodes, nerves. (Jean Lobstein, French pathologist and surgeon in 1829—coined the term retroperitoneal tumour.)

Other tissues refer to—tumours of retroperitoneal organs such as kidneys, ureters, pancreas and adrenals are conventionally not included in retroperitoneal tumours.

Tumours of mesodermal origin (75%):

Tumours of notochordal or embryonic rest origin:

Tumours of neurogenic origin (25%):

Retroperitoneal Tumour Introduction:

• Uncommon (0.2–0.6% of all tumours)
• Malignant in 80–85% of cases (of these, 35% are sarcomas).
• Sex: No differences
• Age: Most occur between the sixth and seventh decade of life.
• Because of their location, these lesions usually demonstrate indolent growth and present as relatively large lesions.
• Their proximity to vital structures (especially vascular) makes resection difficult.

Retroperitoneal Tumour Aetiology:

1. Idiopathic: The actual cause is not known.
2. History of radiation: Accidental or given for lymphoma.
3. Exposure to vinyl chloride/thorium dioxide
4. Familial disorders: Gardner’s syndrome, familial neuroblastoma, neurofibromatosis, Li-Fraumeni syndrome.

Retroperitoneal Tumour Symptoms of RPT:

• Abdominal mass (80%): Slow growing painless mass is the most common presentation. Typically confined to one side rather than centre.
• Nausea, vomiting and weight loss in about 20 to 30% of patients.
• Compressive symptoms: Abdominal pain, constipation, recent haemorrhoids, haematochezia can occur. Back pain and sciatica (30%) are common and are confused for spine pathology.
  Unilateral lower extremity oedema and pressure symptoms including secondary varicosities are common.
  Acute urine retention, dysuria and increased frequency can occur due to compression on urinary bladder.

Retroperitoneal Tumour Signs of RPT:

• Usually large abdominal mass, firm to hard, irregular.
• Nonmobile, restricted mobility
• Not moving with respiration
• Does not fall forward (knee elbow position)
• Resonant tone on percussion—due to bowel anteriorly.
• Transmitted pulsations may be felt.

Retroperitoneal Tumour Differential Diagnosis:

• Lymphoma
• Germ cell tumours
• GIST
• Metastatic testicular cancers

Retroperitoneal Tumour Investigations:

Preoperative planning to assess the extent of the disease is essential because successful surgery is defined by complete excision of the mass with adequate margins of normal tissue.

1. CBP
2. LFT: Increased alkaline phosphatase may indicate secondaries.
3. RFT: Compressive uropathy with high urea and creatinine.
4. Tumour markers: AFP, beta-HCG—germ cell tumour.
5. LDH in lymphoma/GCT: LDH levels indicate tumour burden and growth rate.
6. CT scan:
   • Delineate the anatomic limits of the lesion.
   • Vascular involvement—vena cava, aorta, renal vessels.

• Assess the integrity and function of adjacent organs—renal function is one of the important advantages of CT scan.
• Visceral metastases +/–. If present, it is inoperable but still worth trying a resection after giving neoadjuvant therapy.
• Para-aortic, iliac, mesenteric lymphadenopathy.
• Axial skeleton and renal involvement (Key Box 45.22).

7. CT-guided core biopsy: Reserved for cases in which a diagnosis will change therapy, such as the need for neoadjuvant chemotherapy for:

• GIST—imatinib mesylate
• Germ cell tumours
• Lymphomas

8. Laparoscopic biopsy/retroperitoneoscopy:

• Equivocal history and diagnostic dilemma
• Unusual appearance of the mass
• Unresectable tumour
• Distant metastasis

Retroperitoneal Tumour Treatment:

Surgery is the main modality and the most effective modality of the treatment. It can be curative, if R-0 resection is achieved. Chemotherapy, radiotherapy are complementary to surgery. A few cases are also managed by neoadjuvant therapy.

1. Surgery:

Principles: Extirpative surgery is the principal and most effective form of therapy for primary retroperitoneal tumours. Tumour histology, tumour size, or patient age are not significant factors in survival in multiplevariable analysis. Therefore, carefully planned and skillfully executed surgical therapy is critical for any chance at long-term success.

Adjuvant therapy: High local recurrence rate and eventual mortality from this disease has prompted the exploration of adjuvant therapeutic modalities. Postoperative radiation increases toxicity to surrounding structures.

2. Radiotherapy:

• Radiotherapy:
  • Two types:
    • EBRT—external beam radiotherapy
    • Brachytherapy for retroperitoneal leiomyosarcoma.

Radiotherapy Advantages:

• The viscera are often displaced by the tumour volume and a lack of surgical adhesions further reduces dose to the bowel.
• Effective radiation dose is lower in the preoperative setting.

3. Chemotherapy:

• Doxorubicin is the foundation for chemotherapy in advanced sarcoma.
• MAID regimen: Mesna, adriamycin (doxorubicin), ifosfamide, and dacarbazine have been successful in neoadjuvant programmes for sarcomas of the extremities compared with historical controls.

Differential Diagnosis Of Retroperitoneal Sarcoma

These are pathological variants. It is difficult to consider them as a diagnosis on clinical grounds. However, more common ones have to be considered first such as liposarcoma. Patients with von Recklinghausen’s disease may have neural tumours. A few differential diagnoses are given below.

Liposarcoma:

Most common of primary RPT, 20% from retroperitoneum.

• Liposarcoma Histological types:
  • Well-differentiated liposarcoma (low grade)
  • Myxoid/round cell liposarcoma (50%—most common)
  • Pleomorphic liposarcoma (10–15%—high grade)
  • Dedifferentiated liposarcoma—the rate of metastasis depends on the degree of tumour differentiation, with nearly 90% of poorly differentiated tumours metastasizing.
• Liposarcoma Pathology: The key feature of a liposarcoma is the lipoblast, which is essentially an immature fat cell. LIPOBLASTS have multiple fat vacuoles which compress the nucleus, creating a scalloped appearance.

Leiomyosarcoma:

• 50% from retroperitoneum—Female: Male—2:1
• Site of origin (soft tissue, vascular or superficial), although many of the soft tissue lesions are believed to originate from smaller blood vessels.
• Immunohistochemistry stain for smooth muscle myosin, vimentin, and actin and less often for desmin. (Leiomyomas stain positive for desmin, which separates them from their malignant counterpart.)
• They stain negative for S-100.

MFH (Malignant Fibrous Histiocytoma):

• Less common in the retroperitoneum.
• Derived from fibroblast differentiation (previously defined as a sarcoma of primary histiocytic origin)
• Storiform-pleomorphic (40–60%) and myxoid type (25%) are subtypes. Other types are giant cell type and inflammatory.

Retroperitoneal Teratoma:

• These are the tumours arising from totipotential cells.
• Thus, they can have ectoderm, mesoderm or endoderm elements.
• 10% of all primary RPT.
• Rare in adults because of its congenital nature.
• Solid teratoma is malignant (likely).
• Malignant mature cystic teratomas (0.2 to 2% of cases) have the potential to metastasise to sites such as the retroperitoneal lymph nodes and lung parenchyma.

Rhabdomyosarcoma:

• 6% in retroperitoneum
• More common in children
• Sporadic—most common
  • Genetic risk factor—10–33%: Li-Fraumeni syndrome, neurofibromatosis.

Schwannoma:

• Majority has mutations in NF2 gene.
• Majority are sporadic tumours.
• A minority (10%) are associated with syndromes, such as neurofibromatosis type 2, schwannomatosis and multiple meningiomas.
• Hallmark of schwannoma is alternating areas of cellular (Antoni A) and hypocellular (Antoni B) areas.
• Retroperitoneal tumours are larger and often show degenerative changes, such as cystic change, haemorrhage and calcifications.
• Immunohistochemistry: Diffuse S-100+ is characteristic.

Peritoneum Peritoneal Cavity Mesentery And Retroperitoneum Multiple Choice Questions

Question 1. One need not close peritoneal layer after laparotomy because:

1. The peritoneum can get stuck to the bowel
2. Flattened mesothelial cells heal within a few hours
3. The peritoneum tears when closure is attempted
4. It is very painful postoperatively

Answer: 2. The peritoneum tears when closure is attempted

Question 2. Peritoneum can be used for dialysis because:

1. It is close to kidney
2. It is faster than haemodialysis
3. Capillaries and lymphatics between two layers of peritoneum help in absorption and exudation
4. It covers entire abdomen

Answer: 3. Capillaries and lymphatics between two layers of peritoneum help in absorption and exudation

Question 3. Which of the following is an example of primary peritonitis?

1. Tuberculous peritonitis
2. Perforation peritonitis
3. Postoperative peritonitis
4. Parturition peritonitis

Answer: 1. Tuberculous peritonitis

Question 4. Which of the following organisms are most commonly involved in secondary peritonitis?

1. Enterococci
2. Streptococci
3. Staphylococci
4. Pneumococci

Answer: 1. Enterococci

Question 5. The following are the typical features of acute generalised peritonitis except:

1. Abdominal pain
2. Persistent vomiting
3. Bradycardia
4. High-grade fever with chills

Answer: 3. Bradycardia

Question 6. Abdominal tap is done in peritonitis for all of the following roles except:

1. Aspiration of blood to indicate haemoperitoneum
2. Aspiration of pus indicating infection with gramnegative bacteria
3. Aspiration of bile indicating biliary peritonitis
4. Aspiration of urine indicating ureterocele

Answer: 4. Aspiration of urine indicating ureterocele

Question 7. The following suture material is best suited for closure of bowel perforation:

1. Silk
2. Catgut
3. Nylon
4. Thread

Answer: 1. Silk

Question 8. History of discharge per rectum for the first time in a patient who is recovering from peritonitis suggests:

1. Anal prolapse
2. Pelvic abscess
3. Proctitis
4. Colitis

Answer: 2. Pelvic abscess

Question 9. What forms the anterior relationship of Rutherford Morrison’s space?

1. Liver
2. Kidney
3. Diaphragm
4. Duodenum

Answer: 4. Duodenum

Question 10. Subphrenic abscess is common on the right side because of the following reasons except:

1. Majority of the diseases affect right side
2. Right lung is larger
3. Left paracolic gutter is narrow and colophrenic ligament is present on the left side
4. Right paracolic gutter is large and colophrenic ligament is absent on the right side

Answer: 2. Right lung is larger

Question 11. Indications for open drainage of subphrenic abscess include the following except:

1. Persistent fistula discharging pus
2. Thick viscid pus
3. Abscess very close to IVC/diaphragm
4. Single loculus

Answer: 4. Single loculus

Question 12. Intra-abdominal pressure exceeds ________ cm H2O in abdominal compartment syndrome.

1. 15
2. 25
3. 35
4. 45

Answer: 3. 35

Question 13. Following are features of tuberculous peritonitis except:

1. Tubercles over peritoneal surface
2. Encysted form
3. Can be a miliary form
4. Transudate

Answer: 4. Transudate

Question 14. Nonoperative treatment for peritonitis may be followed in the following except:

1. Moribund patients
2. Sealed perforation
3. Localised peritonitis
4. Generalised peritonitis

Answer: 4. Generalised peritonitis

Question 15. The following catheters are commonly used for percutaneous drainage of subphrenic abscess:

1. Pigtail catheter
2. Trocar catheter
3. Sump catheter
4. Foley’s catheter

Answer: 1. Pigtail catheter

Question 16. More reliable sign of peritonitis is:

1. Cough tenderness
2. Tenderness on pressure
3. Rebound tenderness
4. Guarding

Answer: 3. Rebound tenderness

Question 17. Presence of sunken eyes, pale and pinched face, dry cracked tongue, cold perspiration and cyanosis are all typical features of:

1. Hippocratic facies
2. Gargoyle facies
3. Marshall hall facies
4. Mask like facies

Answer: 1. Hippocratic facies

Question 18. Following are risk factors for spontaneous bacterial peritonitis except:

1. Cirrhosis
2. Nephrotic syndrome
3. Chronic renal failure
4. Carcinoma stomach

Answer: 4. Carcinoma stomach

Question 19. Which of the following is true for pneumococcal peritonitis?

1. Common in young boys
2. Age is around 15 years
3. Peritoneal fluid is transudate
4. It is typically odourless

Answer: 4. It is typically odourless

Question 20. Following are about pseudomyxoma peritonei except:

1. Common in women
2. Ovary is the main source
3. Surgery cannot cure the disease
4. Chemotherapy is also used

Answer: 2. Ovary is the main source