Duplication cyst of the pylorus--a rare cause of gastric outlet obstruction in the newborn.MP Patel, IV Meisheri, VS Waingankar, S Ramesh, AM Naregal, PB Muthaal
Bai Jerbal Wadia Hospital for Children, A.D. Marg, Parel, Mumbai, India., India
Duplication cysts of the pylorus are the rarest of alimentary tract duplications with very few reported cases. We present such a cyst in a neonate presenting with gastric outlet obstruction. We have also reviewed the literature and outlined the theories of origin, modes of presentation, diagnosis and the surgical procedures. Even though several modes of surgery have been described, it is best to individualize the surgical option in each case. The results depend on the nature and site of duplication, complications and the associated anomalies.
Keywords: Case Report, Cysts, congenital,radiography,surgery,Diagnosis, Differential, Gastric Outlet Obstruction, congenital,radiography,surgery,Human, Infant, Newborn, Male, Pylorus, abnormalities,
Gastroduodenal duplications are the rarest of alimentary tract duplications, pyloric duplications are still rarer. We came across a rare case of pyloric duplication presenting as gastric outlet obstruction in a newborn child. We have also discussed the pathology, clinical presentation and the surgical options for these anomalies.
A 3 day old full term male infant was brought with a history of non-bilious vomiting following each feed. The parents also noticed an upper abdominal lump. The child was active, pink and crying well. There was mild dehydration and an incteric tinge with an epigastric lump, which was firm, non-tender freely mobile and separate from the liver. There was no other positive finding on systemic examination. The plain X-ray showed a distended stomach [Figure - 1]. The sonography revealed a cystic mass in the upper abdomen below the liver suggestive of ? choledochal cyst, ? duplication cyst.
After correcting the dehydration, the child was taken for surgery. On exploration, there was a cystic mass measuring 8x5 cm at the pyloric region almost encircling the pylorus and compressing the pylorus and the proximal duodenum [Figure - 2]. The cyst was excised along with the adjacent pylorus in what amounted to a limited pyloroantrectomy. The duodenum was anastomosed to the stomach in a Billroth I fashion.
The child had a good post-operative period and tolerated oral feeds after the peristalsis had resumed. The child was alright till the tenth post-operative day. Unfortunately, he developed pseudomonas meningitis in the next few days and succumbed after 5 more days despite vigorous antibiotic therapy.
On histopathological examination, the cyst wall was found to have smooth muscle coat, sub-mucosa and intact gastric epithelium without any evidence of peptic ulceration.
Alimentary tract duplications are rare anomalies. Gastric duplication are even rarer with only a handful of cases being reported. All the case reports and reviews have collected cases over several years and even decades,,,,,,,,.
There have been several theories of embryologic origin like incomplete twinning, phylogenetic reversal, persistent embryonic diverticula, dysvacuolation and tracheo-bronchial foregut duplication theory and have been well reviewed by Lister. The `Split notochord theory’, is widely accepted and it explains the frequently associated vertebral anomalies.
The recommended criteria for diagnosis of duplication cyst include:
1. Proximity to the alimentary tract.
2. Common blood supply
3. Outer smooth muscle coat which is usually common with the gastric muscle coat.
4. Alimentary epithelial lining (not necessarily of the adjacent gut).
The usual location of gastric duplication is along the greater curvature. More often than not, there is no communication with the stomach. The incidence is twice as common in females as in males,. Associated anomalies can occur in upto 50% of cases and can include other alimentary tract duplications and vertebral defects.
Symptoms vary according to the location of the cyst. The usual presentation is with abdominal mass, vomiting, weight loss and failure to thrive,. Cysts near the pylorus, as in our case, is known to present in the neonatal period with persistent non-bilious vomiting simulating hypertrophic pyloric stenosis,,. In older children, it may present with abdominal pain, gastrointestinal bleeding and fever. These complications are attributed to inadequate drainage of the pent up acid pepsin secretions leading to ulceration, haemorrhage and perforation. The fever is said to be because of infection.
Although the usual age of presentation is early infancy, most are manifest by one year of age. Rare cases have been reported in a 41 year old male and a 64 year old woman who had a malignancy in the duplicated portion.
Gastric duplication may in some way force a malunion of the pancreatic anlage, as is evident from the case reports of association with aberrant pancreas, communication with a pancreatic duct, erosion into a pseudocyst and as a cause of relapsing acute pancreatitis.
Kremer suggests that a gastric duplication cyst should strongly be suspected in a female child (especially less than one year of age) presenting with an abdominal mass pain, vomiting and anaemia and if associated with X-ray evidence of indentation along the greater curvature and depression of transverse colon.
Surgery is the undisputed line of management but the surgical option vary. It is important that the surgery be individualised to each case. The surgeries performed have varied from simple excision with or without a margin of the adjacent stomach to even gastrectomy.
The stomach has blood supply on both sides unlike the mesenteric blood supply of the intestines. Hence instead of resection of the involved segment of the bowel, it is sufficient to excise the cyst alone with the stripping of the resiaul mucosal lining; the raw surface being patched with transverse colon (for large defects) or omentum, or even leaving a sero-muscular gap, like following a Rammstedt’s pyloromyotomy. There are reports of excision procedures like a limited pyloroantrectomy, like in our case, to even gastrectomies.
In all surgical procedures, it is essential to remove all of the cyst lining. Drainage procedures are only rarely advisable like when extensive resection would otherwise be necessary because of huge size or close proximity to the common duct etc. Procedures like cystgastrostomy, cystenterostomy Roux en Y and a `window’ procedure, have all been done in various situations. Marsupialization has to be avoided.
Asymptomatic cysts should possibly be removed because of possible late complication.
The results depend on the type of duplication, the presence of complications and especially on the associated malformations.
However, in this modern era, with the sophisticated specialised care available, it should be possible to salvage most of these children.
[Figure - 1], [Figure - 2]