Abstract
Low anterior resection, performing total mesorectal excision with appropriate pelvic dissection to prevent local recurrence, is probably the most challenging type of surgery in colorectal surgery, especially in a narrow pelvis. In this study, we aimed to predict the operation difficulty of rectal cancer by comparing the operation time with 2D and 3D pelvimetry. Sixty-six patients who underwent total mesorectal excision after neoadjuvant chemoradiotherapy due to primary rectal cancer located in the middle and lower rectum (10 cm from the anus) were included in the study. Surgery notes were reviewed and data on demographic factors, tumor stage, duration of surgery, and types of surgery were collected, as well as pelvimetric parameters. All protocols had 2D T2-weighted sequences in 3 planes (axial, sagittal, and coronal). Pelvimetric measurements were made by measuring 8 pelvic lengths and 2 angles. Pelvis and tumor volume were measured by manual margin monitoring. In each slice, both pelvis and tumor boundaries were manually drawn individually in the sagittal plane. Pelvis and tumor volumes were calculated from the set of adjacent images by summing slice thickness and products of area measurements within the pelvis and tumor boundaries. In our results, no correlation was observed with operation time, including pelvic volume. Exception for this were interacetabular distance and tumor volume. In the regression test, the only parameter that correlated with the operation time was tumor volume. In conclusion, we believe that tumor volumetric calculations may be useful in predicting difficult distal rectal carcinoma surgeries.