Clinical features of congenital hypertrophic pyloric stenosis. What is its operative treatment? What are the postoperative complications? [TU 2059]
What is Meconium ileus?
- Meconium ileus is a unique form of neonatal obstruction that occurs in infants with cystic fibrosis (CF), an autosomal recessive disorder resulting from a mutation in the CF transmembrane regulator gene (CFTR).
- The abnormal chloride transport in patients with CF results in tenacious viscous secretions with a protein concentration of almost 80% to 90%.
Clinical features of Meconium ileus?
- Infants present with three cardinal signs in the first 24 to 48 hours of life:
- (1) generalized abdominal distention;
- (2) bilious emesis; and
- (3) failure to pass meconium
- Maternal polyhydramnios
- It can be simple or complicated.
- Simple - no perforation
- Complicated - with perforation of intestine
X-ray finding in Meconium ileus?
- Dilated and gas-filled loops of small bowel
- Absence of air-fluid levels
- Mass of meconium in the right side of the abdomen mixed with gas to give a ground-glass or soap bubble appearance
Gastrografffin contrast enema finding in meconium ileus?
- A small narrow caliber colon
- Inspissated meconium pellets in the terminal ileum.
Diagnostic test for Cystic fibrosis?
- The pilocarpine iontophoresis sweat test revealing a chloride concentration higher than 60 mEq/L is the most reliable and definitive method to confirm the diagnosis of CF.
- Detection of the mutated CFTR gene.
Management of meconium ileus?
5 mL of 10% N-acetylcysteine (Mucomyst) solution administered every 6 hours through a nasogastric tube. N-Acetylcysteine serves to break the disulfide bonds.
If fail to relieve obstruction, surgical management.
Surgical management - enterotomy, irrigation with warmed saline solution or 4% N-acetylcysteine, and simple evacuation of the luminal meconium without a stoma. After the obstruction is relieved, the enterotomy is closed in standard fashion. If meconium evacuation is incomplete, a T tube may be left in place in the ileum to facilitate continued postoperative irrigation.
For complicated meconium ileus, manage non-operatively with enema and polyethylene glycol purging solution.
What is meconium plug syndrome?
Meconium plug syndrome is unrelated to meconium ileus and in most cases is not a sequela of CF. However, it is a frequent cause of neonatal intestinal obstruction and is associated with a number of conditions, including Hirschsprung’s disease, maternal diabetes, and hypothyroidism.
Describe the pathophysiology of Hirscshprung's disease. Discuss the recent concept in its management [TU 2062,68]
Short note on Hirshsprung's disease. [TU 2066, 2073]
What is Hirshsprung's disease?
- Hirschsprung’s disease is a developmental disorder characterized by an absence of ganglion cells in the myenteric (Auerbach) and submucosal (Meissner) plexus.
- This neurogenic parasympathetic abnormality is associated with muscular spasm of the distal colon and internal anal sphincter, resulting in a functional obstruction. Hence, the abnormal bowel is the contracted distal segment, whereas the normal bowel is the proximal dilated portion.
- Aganglionosis begins at the anorectal line, and the rectosigmoid is affected in approximately 80% of cases, the splenic or transverse colon in 17%, and the entire colon in 8%.
- The area between the dilated and contracted segments is referred to as the transition zone.
tClinical features of Hirshsprung's disease?
- Most infants (>90%) present with abdominal distention and bilious emesis with failure to pass meconium within the first 24 hours of life.
- Infants whose Hirschsprung’s disease is not recognized early may present with a chronic history of poor feeding, abdominal distention, and significant constipation.
- Enterocolitis is the most common cause of death in patients with uncorrected Hirschsprung’s disease.
Diagnosis of Hirshsprung's disease?
- In patients with Hirschsprung’s disease, spasm of
- the distal rectum usually results in a narrow caliber with a transition zone and dilated proximal sigmoid colon. In a study with normal findings, the rectum is wider than the sigmoid colon.
- A rectal biopsy is the gold standard for the diagnosis of Hirschsprung’s disease. It is important to obtain biopsy specimens at least 2 cm above the dentate line to avoid sampling the normal aganglionated region of the internal sphincter. Absent ganglia, hypertrophied nerve trunks, and robust immunostaining for acetylcholinesterase are the histopathologic criteria.
Management of Hirshsprung's disease?
A diverting colostomy (end or loop) is performed in the region of normal ganglionated bowel, and a definitive procedure is performed at a later age.
- Definitive surgical options
- 1. Swenson procedure - the aganglionic bowel is removed down to the level of the internal sphincters and a coloanal anastomosis is performed.
- 2. Duhamel procedure - the aganglionic rectal stump is left in place and the ganglionated normal colon is pulled behind the stump. A stapler is then inserted through the anus, with one arm within the normal ganglionated bowel posteriorly and the other in the aganglionic rectum anteriorly. Stapling results in the formation of a neorectum that empties normally because of the posterior patch of ganglionated bowel.
- 3. The Soave technique involves an endorectal mucosal dissection within the aganglionic distal rectum. The ganglionated normal colon is then pulled through the remnant muscular cuff, and a coloanal anastomosis is performed. The Soave procedure is also performed entirely through a transanal approach
What is Biliary atresia?
Biliary atresia (BA) is a rare disease of neonates characterized by the inflammatory obliteration of intrahepatic and extrahepatic bile ducts.
Pathophysiology of Biliary atresia?
- Ductal injury is immune mediated—inflammatory cells infiltrate and obliterate the bile ducts.
- Another theory is that a viral insult, group C rotavirus infection, triggers the immune-mediated fibrosclerosis and obstruction of the extrahepatic bile ducts.
- Another hypothesis is that there are genetic components that contribute to the development of BA. There may be an association with human leukocyte antigen (HLA) type.
Types of Biliary atresia?
- Type 1 - patency to the level of the common bile duct;
- Type 2 - patency to the level of the common hepatic duct
- Type 3 - 90% of cases, occurs when the left and right hepatic ducts at the level of the porta hepatis are involved
Clinical features of Biliary atresia?
- Infants present shortly after birth with jaundice, pale stools, and dark urine. Older infants may have failure to thrive and present with hepatomegaly and ascites suggestive of cirrhosis. If, in the postnatal period, the jaundice persists after 14 days in a term infant, an evaluation for liver disease should be initiated.
- Other exclusion studies include serologic testing for TORCH (toxoplasmosis, rubella, cytomegalovirus, and herpes) and hepatitis B and C infections, α1-antitrypsin, and CF.
Evaluation of Biliary atresia?
- Ultrasound - gallbladder may be atrophic or absent, and intrahepatic ducts may also be notably absent. The liver may appear echogenic.
- HIDA scan would reveal uptake of the technetium isotope but an absence of emptying into the duodenum.
- MRCP or ERCP can better define the biliary anatomy, but because of the relatively small size of the ducts, it is difficult from a technical and resolution standpoint.
Treatment of Biliary atresia?
Kasai hepatoportoenterostomy is the surgical procedure of choice. Here, the extrahepatic biliary tree is dissected proximally to the level of the liver capsule, where the porta hepatis (portal plate) is transected. The reconstruction is performed by a Roux-en-Y hepaticojejunostomy.