Abdominal Wall Hernia Notes

Abdominal Wall Introduction

• The abdominal wall consists of skin, muscles, aponeurosis, linea alba, sheaths, ligaments, openings, rings, blood vessels and nerves.
• Thus it is a complex structure. Anatomical weak areas are rings, junctions, empty spaces, and blood vessel piercing, weakness of these structures results in hernias.
• Weakness of muscles can also be due to damage to nerves, e.g. as in surgeries such as appendicectomy wherein the ilioinguinal nerve may get damaged resulting in inguinal hernia
• Empty spaces next to arteries are for the expansion of veins but that may cause hernia.

Read And Learn More: Gastrointestinal Surgery Notes

Example: Femoral hernia through medial empty space in the femoral sheath.

Boundaries: The roof is formed by the diaphragm. The pelvis forms the inferior boundary with the perineum which is the central muscular portion.

Laterally, 3 abdominal muscles each having a separate sheath run across towards the midline and form a rectus sheath (details later). The rectus sheath covers strong rectus abdominis muscles that extend from the ribs to the pelvis.

Femoral Hernia

Anatomical Significance

• Rectus sheath: The posterior rectus sheath is absent below the semilunar line. More chances of hernia.
• Linea alba: White, relatively avascular, broad above and narrow below—surgical incision in the midline can be made without any blood loss. Hernia of the linea alba occurs through the opening pierced by a blood vessel.
• Umbilicus: A strong fibrous ring can also be the site of infections and weakness causing umbilical hernias.
• Tendinous intersections in the rectus sheath and branches of superior and inferior epigastric arteries run within the rectus sheath, posteriorly—rectus sheath haematomas are always confined within.
• The nerve supply comes from the lateral side. Hence, traction or retraction of the rectus should be done laterally so as to avoid traction injuries to nerve fibres.
• Blood vessels like superior and inferior epigastric arteries run within the rectus sheath, posteriorly. Haematoma can occur due to rupture but it is confined within the rectus sheath.
• Weak muscles—interstitial hernias—Prune-Belly syndrome—a partial or complete lack of abdominal muscles. There may be wrinkly folds of skin covering the abdomen and undescended testicles in males.
• Some Interesting Diseases Of Umbilicus Ramirez component separation or slide operation is based on making relaxing incisions over the lateral muscles and sliding them medially so as to cover large abdominal wall defects.

Pyogenic Abscess

The abdominal wall is one of the sites of pyogenic abscesses especially in diabetic patients. It is a part of pyaemiLocalised tenderness suggests an abscess. Diagnosis can be confirmed by ultrasound and it is treated by incision and drainage.

Abdominal Wall Veins

• Veins are seen in portal hypertension. In relation to the umbilicus, they are called caput medusae. The direction of the veins is important which can be demonstrated by emptying the vein and filling it.
• In cases of inferior vena cava obstruction, veins are seen on the flank. These veins are called inguinoaxillary veins.

Femoral hernia

Burst Abdomen Abdominal Dehiscence

• A soundly healed abdominal scar can withstand any amount of intra-abdominal pressure. However, 1–2% of the abdominal wounds (incisions) give way resulting in prolapse of intra-abdominal contents outside.
• This causes great concern or anxiety to the patient, and more so for relatives.
• It is said that the anxiety and worry caused by the intestines prolapsing out is much more than that is caused by emergency re-explorations for open cardiac surgery.
• It is not possible to prevent wound dehiscence totally because causative agents are multifactorial.

Factors Responsible for Wound Dehiscence

1. Surgery: It depends upon the type of surgery done. Surgery done for grossly contaminated cases such as peritonitis, biliary fistula or faecal fistula has a high incidence of wound dehiscence.
2. Sepsis: Uncontrolled infection (sepsis) can digest the suture material used and will result in a burst abdomen.
3. Suture material used: Absorbable sutures, such as catgut, give rise to an increased incidence of wound dehiscence than nonabsorbable sutures.
4. Surgeon-related factors: Meticulous dissection, haemostasis, gentle handling of tissues, a good tensionless tight closure, and carefully judged incisions will have reduced the incidence of burst abdomen. Midline vertical incisions have a decreased chance of wound dehiscence than the paramedian incisions.
5. Sick patient: Patients with malignancy, jaundice, obesity, anaemia, hypoproteinaemia, and uraemia have poor wound healing.
6. Straining: In the postoperative period, violent cough, persistent vomiting, and abdominal distension due to paralytic ileus predispose to burst abdomen.

Burst Abdomen: Factors

• Surgery → Peritonitis
• Sepsis → Uncontrolled infection
• Sutures → Absorbable—catgut
• Surgeon → Poor quality
• Sick patient → Malignancy, diabetes, uraemia, jaundice
• Straining → Coughing, vomiting

Remember the causes of burst abdomen as 6 Ss

Burst Abdomen Abdominal Dehiscence Clinical Features

• Patients who are recovering reasonably well in the postoperative period suddenly complain of pink- or brownish-coloured serosanguinous discharge. It is the pathognomonic sign of a burst abdomen.
• It usually occurs on the 6th to 8th postoperative day.
• If skin sutures are removed, omentum or small bowel coils will be seen outside. Interestingly, it is a painless, shockless disruption (with) full of apprehension.

Burst Abdomen Abdominal Dehiscence Treatment

• Reassurance
• The bowel or the contents are covered with pads and bandages.
• Emergency surgery and closure is done.

Burst Abdomen Abdominal Dehiscence Principles of Surgery

1. Adequate exposure
2. The bowel is washed with saline and gently replaced into the peritoneal cavity.
3. Edges of the wound/incision are trimmed.
4. A single-layer closure of the abdominal layer, by taking suture bites through the whole thickness of the abdominal wall is done.
   • A few tension sutures tied over a rubber or a plastic tube are placed and removed after 2 weeks.
   • It should be remembered that secondary wound healing is better than primary wound healing and infection rarely occurs.
   • Closer of midline incision: In all cases of midline incision, it is the linea alba with or without anterior fascial layer that is approximated to the corresponding fascia on the other side.
   • ‘Fascia’ usually refers to the anterior rectus fascia, the fascia above the rectus muscles. This fascia holds the abdomen together and is the most important layer of closure.
   • The fascia can extend beyond the muscles and bind to other fascia.
   • An extension of the fascia is called an aponeurosis.

Complications of Wound Closure

1. Early complications:
   • Infection
   • Dehiscence
2. Late complications:
   1. Incisional hernia
   2. Suture sinus
   3. Wound pain

Prevention of Incisional Hernia

Suturing techniques:

• There should be a 1 cm interval between 2 suture bites.
• The length of suture material and length of the wound should be 4:1 or more, definitely not less.

Interrupted vs. continuous technique:

• Continuous is faster, accommodates wound lengthening due to distension, bursting strength of the wound is significantly higher. It minimizes the number of knots and thus lowers the incidence of incisional hernia. A continuous suture also provides more type 1 collagen and thus has higher wound strength. Thus continuous sutures are better than interrupted.
• Disadvantages: Wound security depends on a single strand of suture and a limited number of knots.

Mass closure:

• Incorporate all layers of the abdominal wall (except skin) as 1 structure and suturing is called a mass suture. However, increased chances of hernia and dehiscence can occur following mass closure.
• Layered: Peritoneum, musculo-aponeurotic layer, skin. Adhesions, and longer surgery time, compromise the adequacy of subsequent layer closure.

Aponeurosis only:

• A good approximation of the edges of the aponeurosis. No separation of wound edges. No soft tissue necrosis.
• Not necessary to suture the peritoneum in midline incisions. A good closure of linea alba is all that is required. The peritoneum heals on its own by epithelialisation of mesothelium.

Absorbable vs non-absorbable:

• Non-absorbable sutures are associated with more pain and suture sinuses but less chances of incisional hernias. Example: Polypropylene.
• Equally good results are found with slowly absorbable sutures—slowly absorbing like polydioxanone (PDS) sutures.
• Fast-absorbing sutures are related to a higher rate of incisional hernias. Examples: Catgut or polygalactin (Vicryl).

Antibacterial (PLUS) sutures to prevent SSI:

• The presence of suture material may increase the risk of infection.
• Bacterial growth on suture material appeared to have the characteristics of biofilm formation. Suture with antiseptic may help in reducing complications related to infection of the suture material such as inflammation, pus discharge, etc.
• Technical details about sutures and measures to prevent incisional hernia

Surgeon’s Role in Preventing Incisional Hernia

• Continuous vs. interrupted sutures
• Knotting technique—secure knots
• Suture length/wound length ratio
• Bite-size
• Mass closure vs. aponeurosis only
• Tensionless sutures
• Suture material—nonabsorbable
• Anti-SSI (surgical site infection) measures—prophylactic antibiotics

Continuous Sutures

• Continuous suturing is faster
• Accommodates wound lengthening due to distension
• The bursting strength of the wound is significantly higher
• Minimises number of knots—equivalent or lower incidence of incisional hernia
• Disadvantages (theoretical): Wound security depends on a single strand of suture and a limited number of knots.

Divarication Of Recti

• In this condition, the two rectus abdominis muscles are widely separated (not in the midline).
• Repeated pregnancy in quick succession is the most important cause. Chronic constipation or overstraining may be another factor. Obviously, women are commonly affected.
• Exercises and an abdominal corset are helpful.
• Symptomatic cases are operated on—divaricated recti are brought towards mild
• Mesh repair may be required.

Rectus Sheath Haematoma

The collection of blood in relation to the rectus sheath and muscles occurs due to the tearing of one of the branches of the inferior epigastric artery.

A parietal haematoma occurs usually at the level of the arcuate line. It is an uncommon condition.

Epigastric Hernia

However, the causes can be as follows:

• Trauma: A sudden blow to the abdominal wall.
• Straining: Sudden straining such as a violent cough or vigorous exercise in a muscular man can cause haematoma.
• Pregnancy: Rarely, the cause of haematoma can be pregnancy, in the late trimester. The exact cause is not known.

Rectus Sheath Haematoma Clinical Features

• History of sudden straining or coughing, etc.
• A tender lump develops just below and to the side of the umbilicus at the level of the arcuate line where the posterior rectus sheath is absent.
• Nausea, vomiting, and pyrexia are the other features.

Rectus Sheath Haematoma Differential Diagnosis

Spigelian hernia (it is rare).

Rectus Sheath Haematoma Treatment

• The condition is self-limiting. With antibiotics and analgesics, a haematoma subsides within 5–7 days.
• If it persists or progresses or if there is doubt about the diagnosis, exploration and evacuation of haematoma should be done and the bleeding vessels are ligateThe results and recovery are excellent.

Epigastric Hernia

Meleney’s Progressive Postoperative Synergistic Gangrene

This dangerous complication is rare nowadays, thanks to good pre- and postoperative antibiotics.

Meleney’s Progressive Postoperative Synergistic Gangrene Aetiopathogenesis

• It is caused by the synergistic action of microaerophilic non-haemolytic Streptococcus and Staphylococcus aureus.
• Surgical operations which have increased the risk of Meleney’s gangrene include a perforated appendix, biliary tract surgery, colectomy, etc.
• Atherosclerosis and diabetes are the other precipitating factors. Starts as cellulitis with reddish skin and postoperative fever.
• The spread may occur within 3–5 days, with extensive gangrene and sloughing of the skin of the abdominal wall with purulent discharge.

Meleney’s Progressive Postoperative Synergistic Gangrene Clinical Features

• Postoperative patient with cellulitis of the abdominal wall.
• Fever of moderate degree, an extremely tender abdominal wall and purulent discharge.
• Toxicity and deterioration of general health may follow soon.

Meleney’s Progressive Postoperative Synergistic Gangrene Treatment

1. At the stage of cellulitis: Broad-spectrum antibiotics cover not only the organisms mentioned above but also anaerobic organisms. Thus, a combination of benzylpenicillin, gentamicin and metronidazole is used.
2. At the stage of gangrene: Emergency aggressive debridement is the treatment. Dead skin and subcutaneous tissue are excised, pus drained and the slough is removed.
3. Hyperbaric oxygen may be very useful.
4. Skin grafting is done, once the wound is healed with granulation tissue.

Epigastric Hernia

Fibromatoses Desmoid Tumour

Fibromatoses Desmoid Tumour Classification 

• Superficial or deep. Deep fibromatoses, also called aggressive fibromatoses and desmoid tumours, are encapsulated fibromas which occur in the abdominal wall.
• They arise from the muscles and an aponeurotic layer of the abdominal wall.

Fibromatosis Treatment

Fibromatoses Desmoid Tumour Incidence

• In children, most desmoid tumours are extra abdominal with a female predominance. In young adults, desmoid tumours almost always occur in the abdominal wall (of women).
• Hormonal effects and pregnancy are believed to influence the growth of this tumour.
• Some tumours express hormone receptors (oestrogen and progesterone), and therefore tamoxifen and other hormonal modulators are among the adjuvant therapies for this tumour.

Fibromatoses Desmoid Tumour Aetiopathogenesis

• Childbirth, trauma or operative scars are the possible aetiological factors.
• Desmoid tumour is one of the components of Gardner’s syndrome.
• It is benign but has a tendency to infiltrate the muscles.
• Some fibromas exhibit dysplastic changes. The cut surface is compared to an onion—whorled fibroma with spindle-shaped cells.
• Sarcomatous changes and metastasis do not occur.

Fibromatoses Desmoid Tumour Clinical Features

• Abdominal fibromatosis is far less prone to recurrences than desmoid tumours in other sites.
• It usually occurs in the abdominal wall of women of childbearing age during or after pregnancy.
• Clinically, the lesions present as deep-seated, firm, nonencapsulated, slow-growing, locally invasive and painless masses.
• It typically manifests as a slow-growing, progressive mass that becomes more prominent during abdominal muscle contraction. Mass is in the abdominal wall and is firm to hard in consistency.
• Mesenteric fibromatosis, probably the commonest among the group, usually presents as a slow-growing mass that involves small bowel mesentery or retroperitoneum.
• The recurrence rate of mesenteric fibromatosis seems to be substantially higher in patients who have Gardner’s syndrome than in patients who do not have this syndrome.

Fibromatoses Desmoid Tumour Treatment or Fibromatosis Treatment

• Simple excision results in recurrence. Hence, wide excision with 2–3 cm of normal healthy margins is necessary with reconstruction of the abdominal wall.
• In spite of adequate surgery, 10–20% chances of recurrence occur.

Endometriosis Of The Abdominal Wall

Drugs like sulindac and tamoxifen have also been used here, with some success.

Umbilical Anatomy

• It occurs due to mechanical implantation of endometrial cells during surgery.
• Painful, palpable swelling, and more symptomatic at the time of menstruation are characteristic features. – Perimenstrual cyclical bleeding can occur.
• Oral contraceptive pills may control the symptoms.
• Otherwise, excision of the nodule has to be done.

Peculiarities of Desmoid Tumour

• Uncapsulated fibroma
• Infiltrates muscles, even though benign
• Does not change into sarcoma
• It may be a part of Gardner’s syndrome
• Simple excision results in recurrence
• Wide excision is recommended

Sites of Endometriosis

• Laparoscopic port – Umbilicus
• Gynaecological surgery – Abdominal incision
• Episiotomy – Perineum

Umbilicus Surgical Anatomy And Embryology Multiple Choice Question And Answers

Question 1. The following is not a cause of umbilical faecal fistula:

1. Persistent vitellointestinal duct
2. Tuberculosis
3. Carcinoma
4. Raspberry adenoma

Answer: 4. Raspberry adenoma

Question 2. The following statement is true about burst abdomen:

1. It is very painful
2. It is associated with shock
3. Straining can produce it
4. Conservative management is the choice

Answer: 3. Straining can produce it

Umbilical Anatomy

Question 3. About desmoid tumour:

1. Is a capsulated fibroma
2. Infiltrates muscles
3. Often changes to sarcoma
4. Simple excision is recommended

Answer: 3. Often changes to sarcoma

Question 4. The following is true of Meleney’s postoperative synergistic gangrene except:

1. Is progressive
2. Can occur after appendicectomy
3. Starts as cellulitis
4. Is painless

Answer: 4. Is painless

Question 5. The following is true about rectus sheath haematoma except:

• It can occur with pregnancy
• Sudden straining can precipitate it
• Presents as a painless lump above the umbilicus
• Nausea, vomiting and fever are other features

Answer: 3. Nausea, vomiting and fever are other features

Question 6. The principles of surgery for a burst abdomen include all of the following:

• Layer by layer carefully suture
• Adequate exposure
• Tension sutures
• Trimming of edges

Answer: 1. Layer by layer carefully suture

Question 7. The pathognomonic sign of a burst abdomen is:

• Shock
• Pink or brown serosanguinous discharge
• Pain
• Occurs on the second postoperative day

Answer: 2. Pink or brown serosanguinous discharge

Question 8. Umbilical adenoma:

• Sessile swelling
• Is a premalignant condition
• Can be treated with ligature
• Occurs due to persistent umbilical vessels

Answer: 3. Can be treated with ligature

Umbilical Anatomy

Question 9. Pilonidal sinus is known to occur in the following places:

1. International cleft
2. Umbilicus
3. Interdigital cleft
4. Axilla

Answer: 4. Axilla

Question 10. Meleney’s gangrene is a synergistic gangrene caused by:

1. Streptococcus and Staphylococcus
2. E. coli and Klebsiella
3. Clostridium and Pseudomonas
4. Salmonella typhi and paratyphi

Answer: 1. Streptococcus and Staphylococcus