A Case of Extended Mediastinal and Retroperitoneal Emphysema after Transanal Local Excision of an Early Lower Rectal Adenocarcinoma

: We observed a case of a large collection of mediastinal and retroperitoneal emphysema, which developed after a transanal local excision for an early lower rectal carcinoma and was treated conservatively. An 80's female patient presented with a chief complaint of bowel difficulty, which was diagnosed as mucosal prolapse syndrome with anal sphincter dysfunction. Endoscopic colonoscopy showed full circumferential proliferation of the mucosal membrane including a semicircular protruding lesion, on the upper side of the dentate line. Biopsy revealed findings indicative of an adenocarcinoma(tub1/pap), Group 4. After a sufficient informed consent was taken, a transanal local excision under spinal anesthesia was conducted discontinuously over half of the circumference. The patient underwent partial-thickness excision, partially full-thickness, and the defects are closed as much as possible. A fever of 38 degrees Celsius was recognized on the 1st postoperative day, and a CT scan, on the 2nd postoperative day, showed a large collection of retroperitoneal and mediastinal emphysema tracking upwards to the nasopharynx. Since fever was the only subjective symptom present, antibiotic therapy under fasting was chosen. The mediastinal emphysema had mostly resolved by the 10th postoperative day. Even though standard transanal excision is not a treatment under air supply there is a risk leading mediastinal and retroperitoneal emphysema.