Modified serial techniques "ASTRO" facilitated laparoscopic total mesorectal excision for ultralow-lying rectal cancer in obese male patients: how we do it (with video).

Background: Laparoscopic total mesorectal excision (LaTME) is a technically challenging for ultralow-lying rectal cancer in obese male patients. Herein, we introduced modified serial techniques "ASTRO" to facilitate LaTME, and the short-term outcomes were presented.

Methods: A prospective study (NCT05067413) was conducted between December 2020 and January 2022. The modified serial surgical techniques "ASTRO" included 5 key steps: (1) Anterior peritoneal reflection (APR) dissection at the highest line along with a "n"-shaped membrane bridge; (2) suspending the APR with a purse-string suture through the bladder peritoneum to enlarge the operating space of the anterior rectal wall; (3) traction and counter-traction continuously of the rectum applied with a cotton tape around the rectum; (4) resection of the pelvic rectum on tripartition, followed by the sequence of "posterior > anterior > lateral" principle; and (5) the trans-anterior Obturator nerve gateway was adapted to transect the distal rectum. The operative data and postoperative short-term outcomes were collected.

Results: Twenty-four consecutive patients underwent this procedure successfully. The average body mass index (BMI) was 29.9±1.3. The average of tumor height from anal verge was 4.0 cm (range, 3.0-4.5 cm). The median operating time and blood loss was 217 min (range, 165-420 min) and 50 ml (range, 20-100 ml) respectively. The anterior operation space at the midsagittal plane of the pelvis inlet was increased by 2.0 ± 0.3 cm. The calculated dominant angle was 20 ± 3°. The length of stapling line was 6.8 ± 1.0 cm with 11 cases by one cartridge and 13 cases by 2 cartridges. Eight patients developed postoperative complications including 4 with anastomosis leakage (16.7%), 2 with urinary retention (8.3%), one with anastomotic stenosis (4.2%) and one with ileus (4.2%). All the complications were relatively mild and the patients recovered well.

Conclusion: Modified serial techniques "ASTRO" could expand the operating space and facilitate LaTME in obese male patients, thereby reducing the risk of conversion to open and transanal dissection.