The pull-through: back to the future

Historically, colo-anal pull-through (P-T) has been the first surgical procedure adopted to facilitate a handmade lower anastomosis. Very popular around mid twentieth century, P-T has had poor diffusion, mainly as a consequence of the technical simplifications brought by staplers. Recent literature seems poor on this specific topic, despite description of P-T appears in published series during the reconstructive phase of total laparoscopic protectomies. A comeback of P-T has also been observed as an option with deferred anastomosis, to allow and protect a colo-anal anastomosis in situations at greater risk of dehiscence, avoiding a temporary faecal diversion. After reviewing the most significant aspects of classic techniques of P-T, we report our experience with transanal laparoscopic P-T for distal rectal cancer, presenting a new, modified P-T with deferred anastomosis aimed at improving defecatory compliance.

Between January 2008 and June 2011 we operated in 258 rectal cancers (0-14 cm from the anal verge), 62.79% of which by laparoscopic access (VL), with 218 restorative procedures (84.49%). The colo-anal anastomoses (CAA) were globally 68 (26.35%), of which 48 in VL procedures (70.58%). In 27 of these CAAs we utilised the P-T procedure, with immediate CAA (I-CAA) in 11 cases (all VL) and delayed CAA (D-CAA) in 16 (2 VL), by selective indications. All CAAs were manually fashioned; 6 D-CAA had the addition of a transverse coloplasty. Site of tumor was the lower rectum in 24 patients, with 21 patients receiving preoperative chemoradiation.

There was no operative mortality. Early morbidity: DCAA: 3 pelvic abscesses with stoma formation.

1 intraoperative re-resection and colo-anal anastomosis with stoma formation for defective distal vascular supply. Late morbidity: anastomotic stenosis in 5/12 I-CAA and 4/14 D-CAA controlled by mechanical dilation. Function: 4/7 D-CAA and 4/6 I-CAA nearly complete functional recovery (Kirwan's 1 or 2).

There are selective indications to P-T, when resection and anastomosis is not feasible in one step, or also as a primary restorative option in elective cases when a covering stoma is refused or dangerous.