Congenital transmesenteric strangulated hernia in a neonate: a case report

Introduction

Congenital transmesenteric hernia (CTMH) is a type of internal hernia where bowel loops pass through a congenital defect in the mesentery. Patients present with clinical features suggestive of intestinal obstruction and it is a condition very difficult to diagnose preoperatively. ¹ Delay in identification of the condition may prove fatal. ²

Case report

A full-term 2900 g male infant was delivered vaginally at a peripheral hospital. The perinatal period was uneventful; he had passed urine and meconium within 24 h of life. At home, he was breast-feeding and thriving well until the third week, when recurrent episodes of vomiting began. On the 26th day, his appetite waned, he failed to pass meconium, had bilious vomiting accompanied by abdominal distension. On admission on the 28th day, the baby was lethargic, severely dehydrated and had absent bowel sounds. Abdominal radiography showed dilated gut loops and multiple fluids levels with no evidence of bowel perforation. Abdominal ultrasonography also showed dilated bowel loops with minimal free peritoneal fluid. With a presumptive diagnosis of intestinal obstruction, intravenous fluid resuscitation was given and surgery was planned.

Exploratory laparotomy revealed herniation of the ileal segment through a large (7 × 6 cm) ileal mesenteric defect (Figure 1). The herniated bowel was gangrenous, so a resection of the affected segment was done and an ilio-ileal anastomosis was performed. The mesenteric defect was repaired and no associated bowel anomalies were found. The postoperative recovery was uneventful and the baby was discharged after eight days in a satisfactory condition. OPEN IN VIEWER

Discussion

CTMH was described first by Rokitansky on an autopsy where the caecum had herniated near the ileo-caecal valve. ³ The exact mechanisms of formation of a mesenteric defect are still obscure, but prenatal vascular catastrophe is thought to be the underlying pathological event. ⁴ The severity of vascular compromise determines the size of the mesenteric defect and associated bowel atresia. Other theories proposed to explain the aetiology are: (1) rapid segmental enlargement of mesentery; (2) dorsal mesentery regression; or (3) pressure changes exerted by the colon during physiological mid-gut herniation. ⁴ Association with other diseases such as Hirschsprung disease and cystic fibrosis had been described. ⁵

CTMH is rare, constituting only 5–10% of all diagnosed cases of internal hernia. ⁴ From 1950 to 2016, only 17 cases have been reported in the PubMed database. It may remain asymptomatic in 33% of patients, or may present acutely with strangulation, intestinal perforation, shock and even sudden death. ⁶ Recurrent episodes of abdominal pain and vomiting may occur, which may resolve spontaneously. Radiographic signs are non-specific, ⁷ though computed tomography (CT) images may reveal narrowing of bowel at site of herniation beside ruling out other diseases. CTMH is seldom diagnosed preoperatively owing to its rarity and lack of specific diagnostic criteria. Surgical intervention is mandatory. Occasionally, the bowel is still viable and the only procedure necessary is closure of the mesenteric defect. A high index of suspicion is advised as in all cases of neonatal bowel obstruction, owing to the rapid deterioration of these small patients, whose reserves are limited.