Complexities of abdominoperineal surgery: synchronous resection of an ano-rectal adenocarcinoma and pelvic schwannoma
A 71-year-old asymptomatic gentleman with known history of colonic polyps underwent a follow-up surveillance colonoscopy through the BCSP. He had a background of type 2 diabetes mellitus, ischaemic heart disease and diverticular disease. Colonoscopy revealed a 1-cm firm polypoid mass at the ano-rectal junction (Fig. ). Subsequent endoscopic mucosal resection was performed and the tissue was sent for histological analysis. This confirmed a tubulo-villous adenocarcinoma. As per national guidelines the patient underwent a staging computed tomography (CT) scan. This revealed a 10 × 15 cm homogenous mass arising from within the pelvis (Fig. ). The mass appeared to be continuous with a neural foramen arising from the sacrum. Further imaging confirmed the mass extending into sacral segment S1 inferiorly, lumbar segments L4 superiorly and the bladder anteriorly. A regional multidisciplinary team discussion concluded that abdominoperineal resection (APR) was the most appropriate surgical approach for removal of both pathologies in their entirety.\nWithin weeks the standard approach to an open APR was commenced.\nThe upper and mid-rectum were successfully mobilized from anterior to posterior behind the seminal vesicles using circumferential dissection techniques. Full rectal mobilization was made complex by the large 10 × 15 cm pre-sacral mass obstructing dissection planes down to the pelvic floor posteriorly. The sigmoid colon was subsequently divided ∼15 cm above the peritoneal reflection and retracted anteriorly to allow access to the tumour (Fig. ).\nOn approaching the mass the pre-sacral fascia was opened to the left side of the midline to gain entry to the tumour pseudocapsule. Upon dissection copious bleeding arose from the common iliac vein to which the tumour was adherent. Intra-operative cell salvage was then commenced and haemostasis was achieved with direct pressure and vascular repair with a 4.0-polypropylene suture. The schwannoma was then fully mobilized from its anterior and lateral fascial attachments leaving it attached to the sacrum posteriorly. Lastly, the tumour was separated from the sacrum. Pre-sacral venous bleeding was packed before complex suture ligation and diathermy of disrupted veins achieved haemostasis. The estimated blood loss was ∼1600 ml and this was replaced with 1000-ml cell salvage product together with one unit of cross-matched red cells.\nThe perineal dissection was then completed and an end colostomy fashioned in the left iliac fossa. The abdominal wound was closed en-mass with clips to the skin. The patients' post-operative haemoglobin was 114 g/l. The patient was discharged home 9 days post-operation and remained very well at his 3-month outpatient follow-up. Pathology reports confirmed removal of a pT1N0M0 adenocarcinoma with clear margins in addition to a benign schwannoma.