Umbilical Fistula Abdominal Wall Introduction Surgical Anatomy And Embryology Notes

Umbilicus Surgical Anatomy And Embryology

Umbilicus Surgical Anatomy And Embryology Definition: The umbilicus is the normal scar in the anterior abdominal wall formed by the remnants of the root of the umbilical cord.

The position of the umbilicus is variable. In healthy adults, it lies in the anterior median line, at the level of the disc between the third and fourth lumbar vertebrae.

It is lower in infants and in persons with a pendulous abdomen. It can be displaced upwards as in ovarian tumours.

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Apart from its embryological importance, there are several facts of interest about the umbilicus.

Anatomical Importance

1. With reference to the lymphatic and venous drainage, the level of the umbilicus is a watersheLymph and venous blood flow upwards above the plane of the umbilicus; and downwards below this plane. These do not normally cross the umbilical plane.
2. The skin around the umbilicus is supplied by segment T10 of the spinal cord.
3. The umbilicus is one of the important sites at which tributaries of the portal vein anastomose with systemic veins (portocaval anastomoses). In portal hypertension, these anastomoses open up to form dilated veins radiating from the umbilicus called the caput medusae.
4. However, the blood flow in the dilated veins is normal and does not break the barrier of the watershed line.

Embryological Importance

1. The umbilicus is the meeting point of the four (two lateral, head and tail) folds of the embryonic plate.
2. This is also the meeting point of three systems, namely the digestive (vitellointestinal duct), the excretory (urachus), and vascular (umbilical vessels).

Classification Of Umbilical Diseases

1. Inflammation
   1. Omphalitis
   2. Granuloma
   3. Dermatitis
   4. Pilonidal sinus
2. Fistulae
   1. Faecal
      1. Patent vitellointestinal duct
      2. Carcinoma transverse colon
      3. Tuberculous peritonitis
   2. Urinary: Patent urachus
   3. Biliary
3. Neoplasms
   1. Benign
      1. Adenoma: Raspberry tumour
      2. Endometrioma
   2. Malignant
      1. Primary carcinoma
      2. Secondary carcinoma from the stomach, colon, ovary, and breast
4. Umbilical hernia
5. Umbilical calculus (umbolith)

Umbilical Cord Structures

• In foetal life
• Umbilical vein
• Right and left umbilical arteries
• Urachus
• In embryonic life
• Vitellointestinal duct and structures

Umbilical Inflammation

1. Omphalitis
   1. Inflammation of the umbilical cord due to Staphylococcus aureus and streptococci occurs in the neonatal period 3–4 days after birth. The incidence is increased in hospital births.
   2. Rarely, gram-negative organisms and Clostridium tetani can cause omphalitis,1 if strict aseptic precautions are not taken. If infection is not controlled, it can result in further complications.
      1. Abscess of the abdominal wall: Pus can be seen coming out of the umbilicus. It may need drainage with antibiotic cover. Gentle squeezing will help, followed by antiseptic dressings and systemic antibiotics.
      2. Extensive ulceration of the abdominal wall: similar to Meleney’s ulcer, is a rare complication (subcutaneous synergistic gangrene) of omphalitis.
      3. Septicaemia can occur due to organisms entering the umbilical vein and then into the portal vein. This results in pylephlebitis with jaundice, fever, chills and rigours.
      4. Neonatal jaundice: due to intrahepatic cholangitis.
      5. Portal vein thrombosis resulting in extrahepatic portal hypertension (prehepatic).
      6. An umbilical hernia can occur due to a weak scar produced by sepsis.
2. Granuloma
   1. Granuloma indicates persisting inflammation underneath. It is a cause of great concern and worry to the patients. This can be destroyed by application of copper sulphate or silver nitrate solution.
3. Dermatitis
   1. Dermatitis more often occurs in adults wherein chronic infection of the umbilicus sets in with foul-smelling discharge.
4. Pilonidal Sinus
   1. The umbilicus is a low area compared to the surface of the abdominal wall. Hence, hairy men may shed their hair which accumulates in the umbilicus and may result in pilonidal sinus. It may need the removal of the sinus along with a tuft of hair or rarely the umbilicus itself.

Umbilical Fistulae

Faecal

1. Persistent vitellointestinal duct is an uncommon congenital anomaly.
   • Many a time the intestinal 1Application of cow dung to the umbilical cord is still prevalent in a few places in our country.
   • In addition to causing omphalitis, it can also cause neonatal tetanus. opening is so small that only mucoid contents come out of the umbilicus. Rarely, if the opening is big, omphaloenteric faecal fistula results.
2. Internal hollow viscus malignancies, especially carcinoma of the transverse colon can erode through the umbilicus resulting in a faecal fistula.
3. Tuberculous peritonitis induces dense adhesions, strictures and perforations.
   • A perforation which is sealed off by coils of matted bowel and omentum results in a local abscess which may perforate through a weak point, i.e. umbilicus resulting in a faecobiliary fistula.
   • If a diagnosis can be proved by a wall biopsy of the sinus/fistula, antituberculous treatment can cure the disease.
   • Laparotomy is extremely difficult in such cases. One may end up creating more holes in the bowel which is better avoided.

Patent Urachus

• The ventral urogenital sinus which forms the urinary bladder is continued cranially as urachus which extends into the umbilical cord— allantoic stalk. If this portion persists, patent urachus forms which connects the umbilicus with the urinary bladder. If it is fibrosed, as it occurs normally, it is called the median umbilical ligament. A patent urachus may manifest as urinary discharge from the umbilicus. It manifests usually in childhood and early adult life. In most cases, there will be some kind of obstruction to the normal passage of urine. The entire urachus is excised after correcting distal obstruction.

Biliary Fistula

Rarely, perforation of the gallbladder due to a severe form of cholecystitis may result in a local abscess which may rupture through the umbilicus resulting in biliary fistulInstances are recorded wherein stones have come out of the umbilicus.

Umbilical Neoplasms

An umbilical adenoma is a pedunculated swelling having a raspberry colour. Hence, the name Raspberry Tumour.

• It is due to an unobliterated vitellointestinal duct.
• The Mucosa of the persistent duct prolapses through the umbilicus and produces this adenoma.
• It is moist with mucus and tends to bleed (columnar epithelium rich in goblet cells).

Umbilical Neoplasms Treatment

• If the tumour is pedunculated, a ligature is tied around it and by a few days, the adenoma drops off.
• If the tumour reappears, excision of the umbilicus is advised.

Endometrioma of the umbilicus is rare but patients have a typical history to tell, i.e. it bleeds during menstruation.

Malignant: Secondary carcinomatous nodule in and around the umbilicus reflects advanced malignancy commonly from the stomach and colon.

The ovary, uterus, and breast are other causes. The nodule is tender, fixed and reddish in colour. some interesting diseases of the umbilicus.

Umbilical Hernia

The umbilicus is one of the weak points in the body. Hence, it is one of the sites of hernia All the details of umbilical hernia.

Umbolith

• It is composed of desquamated epithelium which becomes inspissated and gets collected in the umbilicus. With secondary infection, there will be blood-stained discharge. It is treated by controlling infection, debridement and, if necessary, removal of the umbilicus.
• This umbolith or umbilical calculus is black in colour.

Abnormalities of Urachus

• Patent urachus
• Urachal sinus
• Urachal cyst
• Urachal diverticulum