Background/aims: Recently, pelvic anatomy has been taken into consideration and related to surgical outcome indicators after low anterior resection (LAR). Several pelvimetric parameters have been matched with conversion rate, postoperative complications and duration of surgery in laparoscopic series, and with the quality of specimen and pathologic outcomes in further open surgical series.

Methodology: In 97 consecutive patients submitted to sphincter-saving LAR with total mesorectal excision (TME) five pelvic dimensions were measured by abdominal computed tomography scan: anteroposterior and transverse diameters in the pelvic inlet (IAP and ITRA), anteroposterior and transverse diameters in the pelvic outlet (OAP and OTRA), and the pelvic depth. The endpoint evaluated was anastomotic leakage (AL) rate.

Results: There were 51 open, 12 laparoscopic and 34 robotic LARs. The sum of IAP OAP and OTRA (Pelvic Index) significantly predicted AL showing that starting from the cut-point of 290 mm down to a PI of 278 mm the odds-ratio of having an AL increased from 2.63 (95% CI: 1.10,5.47) to 5.07 (95% CI: 1.35,8.02).

Conclusions: The sum of the 3 pelvic dimensions which we termed “Pelvic Index” was associated to AL following sphinctersaving LAR. This may be considered in planning the surgical strategy for rectal cancer patients.