MRI navigation surgery for T4b rectal cancer using multiple minimally invasive surgical approaches

These days, various surgical techniques such as trans-anal, trans-perineal total mesorectal excision, and transvaginal natural orifice transluminal endoscopic surgery have been utilized with flexibility, which was not possible before the laparoscopic era.

From January 2014 to January 2023, 40 cases of c(yc)T4b rectal cancer underwent local curative surgery laparoscopically at Kansai Medical University Hospital. In 25 consecutive cases, we adopted multiple approaches (trans-anal total mesorectal excision, transvaginal natural orifice transluminal endoscopic surgery, trans-perineal total mesorectal excision, or prone position first abdominoperineal excision) to remove the deepest part of the tumor indicated by MRI last as the specimen-oriented surgery. The remaining 15 patients underwent top-to-bottom surgery based on standard surgery. The primary endpoint was the local recurrence rate of the specimen-oriented surgery group compared to that of the standard surgery group.

The specimen-oriented surgery group had a median follow-up of 3.9 (0.4-7.4) years with no local recurrence, while the standard surgery group had a median follow-up of 1.5 (0.7-3.7) years with 5 of 15 patients (33%) experiencing more local recurrence than specimen-oriented surgery group (p = 0.005). Comparison of the local recurrence ( +) and ( -) groups showed significant differences in pCRM positive rate, neoadjuvant therapy, tumor size, and approach (specimen-oriented surgery vs. standard surgery) in univariate analysis (p < 0.05). Still, no significant differences were found in the multivariate analysis.

In the laparoscopic setting, local cure of c(yc)T4b rectal cancer requires a different strategy than open surgery, and specimen-oriented surgery may be a promising procedure.