Factors affecting operating time in laparoscopic anterior resection of rectal cancer

Background: The objective of this study is to clarify the relationship between demographic and surgical factors and operating time, and thus operative difficulty, in patients undergoing laparoscopic anterior resection for mid-low rectal cancer, since different studies have derived different results.Methods: The records of patients with mid-low rectal cancer who underwent laparoscopic anterior resection were retrospectively studied. Demographic data, tumor characteristics, and pelvimetry measurements were collected and analyzed with respect to operating time, using correlation coefficient analysis, principle component analysis, and linear regression.Results: A total of 14 patients (10 males, 4 females; 65.50 ± 7.12 years of age) were included. Demographic and tumor characteristics not correlated with operating time. Body mass index (BMI) (P = 0.001); interacetabular distance (IA) (P = 0.001); anatomical transverse distance (IP) (P = 0.008); interischial distance (IS) (P = 0.002); intertuberous distance (IT) (P = 0.005); distance between the coccyx and symphysis (CoSy) (P = 0.013); and the angle of the lower border of the symphysis pubis, upper border of symphysis pubis, and sacral promontory (angle 5) (P = 0.004) were significantly associated with operating time. The equation was: operating time = 0.653 × BMI + 0.818 × angle 5 - 0.404 × IA - 0.380 × IP - 0.512 × IS - 0.405 × IT - 0.570 × CoSy + 330.8. Conclusions: Transverse diameters of the pelvis, BMI, angle 5, and CoSy played the most important role in affecting operating time. The equation can be a very useful tool for preoperative assessment.