P2.219: Getting Stuck in the Canal: A Case Report of Abdominal Dystocia

Introduction: Abdominal dystocia is a rare phenomenon where an enlarged fetal abdomen fails to pass through the vaginal canal. Meconium peritonitis is a known cause of abdominal dystocia. We present a case of an infant whose delivery was complicated by abdominal dystocia secondary to a large meconium pseudocyst.

Case Description: A female infant at 38 weeks and 2 days had arrest of descent at the fetal abdomen during vaginal delivery. Through the uterus, the obstetrician made an incision into the fetal abdomen after which there was a gush of serous fluid and subsequent decompression allowing the infant to delivery vaginally.
She initially required positive pressure ventilation (PPV) and was transitioned to continuous positive airway pressure (CPAP) when she was noted to have spontaneous respirations. The APGARS were 2, 4, and 7 at 1, 5, and 10 minutes respectively. She was noted to have a large right upper quadrant abdominal laceration. The obstetrician flushed the wound with warm sterile saline and grossly closed the abdomen with interrupted sutures. She was then transferred to the neonatal intensive care unit (NICU).
The infant was started on therapeutic hypothermia due to concern for hypoxic ischemic encephalopathy (HIE) given low tone, poor APGARS, and acidosis. Initial abdominal x-ray showed a linear peritoneal calcification without free air suggestive of meconium peritonitis. She had increasing respiratory distress and was intubated prior to transfer to the tertiary care center for immediate surgical evaluation.
In the operating room, a massive meconium pseudocyst with inspissated meconium in the terminal ileum without any other organ injury was found. The ileum was irrigated with 2% N-acetyl cysteine and an ileostomy with distal mucous fistula was created. She has since undergone re-anastomosis with multiple surgical complications requiring readmission and surgical revisions. Genetic tests (CFvantage panel, CFTR gene sequencing) were negative for cystic fibrosis (CF).

Discussion: Meconium peritonitis is usually caused by a meconium ileus that results in a bowel perforation with extrusion of meconium into the peritoneal space. Meconium pseudocyst formation is a complication of meconium peritonitis where the meconium becomes walled off by adhesions in the peritoneum secondary to inflammation.
The inciting meconium ileus is generally associated with CF. However, our patient has no family history and all genetics have been negative for CF.
Currently there are no recommendations on in utero decompression of the bowel for enlarged fetal abdomens but other case reports note similar success of intrapartum abdominal decompression to facilitate delivery. This method to expedite delivery may improve neurologic outcomes.

Conclusion: Meconium peritonitis with pseudocyst formation may present as abdominal dystocia. These infants can be successfully delivered with abdominal decompression and postnatally treated with surgical intervention including ostomy formation, bowel irrigation, and subsequent re-anastomosis. All infants with a similar presentation should undergo CF testing.