'Natural orifice' transcolostomy full-thickness excision of colonic tumour.

This technical note describes a novel technique, not previously found in the surgical or endoscopic literature: A combined endoscopic and surgical approach to perform a full-thickness excision of a colonic tumour. At the time of colonoscopy via stoma, a large sessile polyp in the descending colon was detected but could not be safely resected endoscopically. The lesion was exteriorised by prolapsing the distal colon through the colostomy, then excised surgically with adequate margins in a full-thickness fashion. This approach was more complete than an endoscopic approach and less invasive than a segmental colectomy and redo colostomy. It may prove useful to surgical endoscopists facing a similar clinical situation in their practice.

INTRODUCTION

Removal of adenomatous polyps is unquestionably the most important step in colorectal cancer prevention. Although most polyps can be safely removed by various endoscopic techniques with forceps or snares, some may pose special challenges as a result of size, shape or location. Several endoscopic techniques have been reported to provide technical tips in such circumstances.[12] In cases not suitable for safe endoscopic removal, a surgical resection may still be necessary, preferably by laparoscopic technique, and assisted by appropriate tattooing techniques.[3] In rare cases, where the polyp is located proximal to a colostomy, a surgical resection and redo of the colostomy may be required.[4] On the other hand, in such a clinical situation, given the growing applications of natural orifice surgical and interventional techniques (natural orifice transluminal endoscopic surgery), one may also consider an even less invasive approach similar to a transanal excision of a rectal tumour.[5] This report describes a new technique, not reported before in the literature, that required no sedation or local anaesthesia, was carried out at the time of colonoscopy and provided equally safe and effective definitive treatment of the tumour.

CASE REPORT

A 74-year-old man, who had undergone a descending colostomy for a sigmoid stenosis secondary to radiation therapy 10 years earlier, underwent a colonoscopy via stoma on March 5, 2015. He was found to have a 4 cm × 2 cm sessile polyp in the descending colon, about 8 cm proximal to his stoma. Given the size of the polyp and its location, an adequate colonoscopic polypectomy could not be carried out, mostly because the lumen of the colon could not be properly insufflated during the procedure and the visualisation was very unsatisfactory. The patient was referred for segmental resection and redo colostomy. On digital and endoscopic examination, the colon appears redundant, and the descending colon proximal to the stoma could be successfully prolapsed by and maintained in an everted position with the assistance of 4 Babcock clamps [Figure 1]. Adequate exposure was achieved and the patient did not require sedation or local anaesthetics. The healthy mucosa, 1 cm from the tumour, was circumferentially marked with a cautery. After traction sutures had been placed, the cautery was also used for the transmural dissection. The tumour was completely excised in a full-thickness fashion and submitted for pathologic examination [Figures 2 and 3]. The bowel wall was closed primarily with a single layer of running polyglactin suture, in a transverse fashion, to maintain an adequate lumen [Figure 4]. The bowel was reduced back deep to the stoma level. The patient left the outpatient facility the same day and had an uneventful recovery. The pathology report revealed a villous adenoma, with severe dysplasia, completely excised with negative resection margins. At 1-year follow-up, there was no evidence of residual or recurrent tumour.

Figure 1

The colonic polyp is maintained in an exteriorised position using Babcock clamps

Figure 2

The polyp is being excised in a full-thickness fashion. Note traction sutures and mesenteric fat

Figure 3

The polyp is completely excised with a 1 cm margin

Figure 4

The colonic defect is closed in a transverse fashion, to prevent a luminal stricture, with full-thickness running absorbable suture material

DISCUSSION

This technical note, after literature review, appears to be the first report of a ‘natural orifice’ transcolostomy excision of a tumour, with a technique similar but not comparable to a full-thickness transanal excision of a rectal tumour. In fact, the ability to prolapse the distal pre-colostomy colon facilitated the procedure, which was done in a completely awake patient, without local anaesthesia, in an ambulatory setting. This technique may prove useful, as a less invasive alternative to segmental resection and redo colostomy. It would be applicable to benign adenomas or carcinoma in situ lesions. It is more definitive and safer than an attempt at colonoscopic polypectomy, where the inability to maintain adequate insufflation of the lumen may lead to inadequate excision or procedure-related complications such as perforation or bleeding.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.