Surgical Techniques for Identification of the Prostate Gland Using the Autonomic Nerve as a Landmark During Transanal Total Mesorectal Excision: Secure Dissection of the Male Rectourethral Muscle

Transperineal minimally invasive abdominoperineal resection for low rectal cancer: standardized technique and clinical outcomes

BACKGROUND

Despite the increasing utilization of transanal total mesorectal excision as a promising approach for low rectal cancer, the feasibility and safety of transperineal minimally invasive abdominoperineal resection (tp-APR) remain unclear.

METHODS

In total, 25 patients who underwent tp-APR between April 2017 and May 2020 (tp-APR group) and 27 patients who underwent conventional laparoscopic APR between May 2009 and September 2016 (lap-APR group) for low rectal cancer were enrolled in this retrospective study. Clinical outcomes were compared between the groups before and after propensity score matching. The primary outcome was the incidence of the overall postoperative complications with Clavien-Dindo grade II or above. Standardized technique of tp-APR was also demonstrated.

RESULTS

On comparison, operative time, intraoperative blood loss, and overall postoperative complications with Clavien-Dindo grade II or above were significantly less in the tp-APR group both before and after propensity score matching. The rates of urinary disturbance and perineal wound infection were significantly less in the tp-APR group after matching. Further, postoperative hospital stay was significantly shorter in the tp-APR group both before and after matching. However, pathological outcomes did not differ between the groups before and after matching. There has been no local recurrence in the tp-APR group with a median follow-up period of 18 months.

CONCLUSION

Standardized tp-APR for low rectal cancer is feasible and seems superior to conventional laparoscopic APR in terms of short-term outcomes. Further larger-scale studies with a longer follow-up period are required to evaluate oncological outcomes.

Gastrointestinal stromal tumor of the rectum resected by transanal total mesorectal excision after neoadjuvant imatinib treatment: A case report

This report describes the combination of a transanal total mesorectal excision (TaTME) and neoadjuvant therapy with Imatinib mesylate (IM) for a gastrointestinal stromal tumor (GIST) of the lower rectum. A 49-year-old man presented with a submucosal tumor with ulcer located 3 cm above the anal verge. Histopathologically, a biopsy showed spindle-shape cells, positive for C-kit and CD34, negative for smooth muscle actin, desmin and S-100 protein. Genetically, this GIST had the mutation in KIT exon 11. IM (400 mg/d) was administered as neoadjuvant therapy for 80 days. The GIST shrank from 4.7 to 3.3 cm in diameter. Abdominal and transanal approach were started at the same time. The tumor was resected by TaTME successfully. The manometric pressure data and anal function were preserved before and after surgery. TaTME and neoadjuvant therapy with IM provide a treatment option which can preserve anal function for the lower rectal GIST.

Transanal TME: new standard or fad?

Transanal total mesorectal excision (taTME) has been developed to overcome the difficulty of laparoscopic dissection and transection in the deep pelvis. TaTME has several clinical benefits over laparoscopic surgery, such as better exposure of the distal rectum and direct determination of distal resection margin. Although evidence demonstrating the true benefits of taTME over laparoscopic TME (LapTME) is still insufficient, accumulating data have revealed that, as compared with LapTME, taTME is associated with shorter operative time and a lower conversion rate without jeopardizing other short-term outcomes. However, taTME is a technically demanding procedure with specific complications such as urethral injury, and so sufficient experience of LapTME and step-by-step acquisition of the skills needed for this procedure are requisite. The role of transanal endoscopic surgery is expected to change, along with the recent progress in the treatment of rectal cancer, such as robotic surgery and the watch-and-wait strategy. Optimization of treatment will be needed in the future in terms not only of oncological but also of functional outcomes.