Background:Perforation of the digestive wall may occur during endoscopic submucosal dissection (ESD) and unless recognized and timely treated it can lead to severe adverse events.  Microperforations may be harder to detect in extensive lesions and prolonged exposure to insufflation can lead to postprocedural emphysema. Recognition and limitation of this uncommon event and appropriate conservative management are essential.

Case presentation:A 71-year-old patient without significant comorbidities underwent screening colonoscopy which revealed an 8 cm, granular mixed-laterally spreading tumor (LST-GM) involving over 80% of the middle rectum. We performed “butterfly-tunneling” ESD under general anesthesia with endotracheal intubation with the patient in left lateral decubitus. The ESD lasted 4 hours and a small perforation was closed via through-the-scope clips halfway through the procedure. Pathology confirmed R0 resection of a traditionally serrated adenoma.

The immediate postoperative course was uneventful. Awaiting discharge at 24 hours the patient developed anterior cervical discomfort and mild dysphonia. Clinical examination identified a peculiar one-sided distribution of subcutaneous emphysema in the latero-cervical region, and palpable crepitus extending along the lateral aspect of the right lower limb. There were no signs of respiratory or haemodynamic compromise or abdominal guarding.

Contrast-enhanced CT confirmed extensive subcutaneous emphysema involving the cervical region, abdominal wall, and right lower limb, without pneumoperitoneum, contrast extravasation, abscess, or active bleeding. On reviewing the procedure, it was apparent that prolonged carbon dioxide insufflation through the 2 mm perforation was likely to have occurred before closing and the left lateral position accounted for the peculiar unilateral distribution of the gas. Delayed resumption of orthostatism finally allowed migration of the free gas along the fascial planes and led to the presenting symptoms.

Careful clinical monitoring and conservative management including short-term fasting, intravenous fluids, and prophylactic antibiotics were initiated. The emphysema regressed spontaneously, and the patient was discharged after 48 hours. Follow-up colonoscopy showed an asymptomatic 12 mm stenosis that was dilated by CRE balloon.

Conclusion:This case illustrates a rare occurrence of post procedural emphysema following rectal ESD due to prolonged insufflation before closure. Conservative treatment led to complete resolution. In protracted procedures using insufflation, rapid closure of potential microperforations is advised as soon as compromise of resection is avoided.