[Current research status on pelvic autonomic nerve monitoring in rectal cancer surgery]

Rectal cancer is a common malignant tumor of the digestive tract, and surgery is the main treatment strategy. Disorders of bowel, anorectal and urogenital function remain common problems after total mesorectal resection (TME), which seriously decreases the quality of life of patients. Surgical nerve damage is one of the main causes of the complications, while TME with pelvic autonomic nerve preservation is an effective way to reduce the occurrence of adverse outcomes. Intraoperative nerve monitoring (IONM) is a promising method to assist the surgeon to identify and protect the pelvic autonomic nerves. Nevertheless, the monitoring methods and technical standards vary, and the clinical use of IONM is still limited. This review aims to summarize the researches on IONM in rectal and pelvic surgery. The electrical nerve stimulation technique and different methods of IONM in rectal cancer surgery are introduced. Also, the authors discuss the limitations of current researches, including methodological disunity and lack of equipment, then prospect the future direction in this field.

[Perirectal fascial anatomy and pelvic autonomic nerve preservation during the transanal total mesorectal excision]

The difficulty of transanal total mesorectal excision (TME) is to find the correct dissection plane of perirectal space. As a complex new surgical procedure, the fascial anatomic landmarks of transanal approach operation are more likely to be ignored. It is often found that dissection plane is false after the secondary injury occurs during the operation, which results in the damage of pelvic autonomic nerves. Meanwhile, the mesorectum is easily damaged if the dissection plane is too close to the rectum. Thus, the safety of oncologic outcomes could be limited by difficulty achieving adequate TME quality. The promotion and development of the theory of perirectal fascial anatomy provides a new thought for researchers to design a precise approach for transanal endoscopic surgery. Transanal total mesorectal excision based on fascial anatomy offers a solution to identify the transanal anatomic landmarks precisely and achieves pelvic autonomic nerve preservation. In this paper, the authors focus on the surgical experience of transanal total mesorectal excision based on the theory of perirectal fascial anatomy, and discuss the feature of perirectal fascial anatomy dissection and technique of pelvic autonomic nerve preservation during transanal approach operation.

Intraoperative radiotherapy for resectable advanced lower rectal cancer-final results of a randomized controlled trial (UMIN000021353)

AIM

Pelvic autonomic nerve preservation (PANP) is useful to preserve voiding and sexual function after rectal cancer surgery. The aim of this study was to investigate the benefit of intraoperative radiotherapy (IORT) to have complete PANP without affecting oncological outcomes.

METHODS

Patients undergoing potentially curative resection of the rectum were included. They were randomized to intraoperative radiotherapy of the completely preserved bilateral pelvic nerve plexuses (IORT group) or the control group without IORT, but with limited nerve preservation. The primary endpoint was pelvic sidewall recurrence. Moreover, patients' clinicopathologic parameters, postoperative complications, voiding function, and other oncologic outcomes were compared.

RESULTS

From 79 patients, three were excluded from analysis, resulting in 38 patients in each group. Patients' demographic and pathological parameters were well balanced between the two groups. The trial was terminated prematurely in July 2017, because distant metastasis-free survivals were found to be significantly worse in the IORT group compared to the control group (odds ratio 2.554; 95% CI, 1.041 ~ 6.269; p = 0.041). Neither overall survival nor pelvic sidewall recurrence did differ between the two groups (overall survival: odds ratio 1.264; 95% CI, 0.523~3.051; p = 0.603/pelvic sidewall recurrence; odds ratio 1.350; 95% CI, 0.302~6.034; p = 0.694). Postoperative complications did not differ between the groups; however, the urinary function was significantly better in the IORT group in the short and long term.

CONCLUSION

With the aid of IORT, complete PANP can be done without increase of pelvic sidewall recurrence; however, IORT may increase the incidence of distant metastases. Therefore, IORT cannot be recommended as a standard therapy to compensate less radical resection for advanced lower rectal cancer.

Prognosis and postoperative genital function of function-preservative surgery of pelvic autonomic nerve preservation for male rectal cancer patients

Background

To retrospectively evaluate postoperative genital function, local recurrence rate and survival rate after total mesorectal excision (TME) combined with or without pelvic autonomic nerve preservation (PANP) in male patients with rectal cancer.

Methods

A total of 953 male patients with rectal cancer after TME (518 patients received TME combined with PANP [PANP group] and 434patients received TME alone [TME group]) were included. Assessments of postoperative genital function, local recurrence rate, and 5 year survival rate were collected.

Results

Rate of erection dysfunction in PANP group (41.9 %) was significantly lower than that in TME group (76.7 %, P < 0.05). Rate of ejaculation dysfunction in PANP group (42.5 %) was also significantly lower than that in TME group (67.3 %, P < 0.05). Local recurrence rate (P = 0.66) and survival rate (P = 0.26) did not differ between the two groups. For patients with preoperative obstruction, local recurrence rate was significantly higher (P = 0.01) and survival rate significantly lower (P = 0.03) in PANP group.

Conclusions

PANP surgery has significant advantage with respect to preservation of genital function and should be recommended as surgical treatment for rectal cancer patients. However, PANP surgery should be considered with caution in patients with preoperative obstruction in view of the poorer long-term outcomes in these patients.

Evaluation of laparoscopic D3 radical correction with pelvic autonomic nerve preservation for rectal cancer

AIM: To evaluate the security and feasibility of laparoscopic D3 radical correction for rectal cancer.

METHODS: Sixty two cases diagnosed as rectal cancer in Duke's stage B or C from January 2007 to June 2008 at our hospital were arranged into two groups, of which, one group underwent open D3 radical correction and the other received laparoscopic D3 radical correction. At the same time, they all received pelvic autonomic nerve preservation.

RESULTS: The average operation time of laparoscopic group was 271 min, somewhat longer than that of open group, but the average hemorrhage volume was less. The detected lymph nodes for laparoscopic group and open group were 23.2 and 22.8, respectively, and no statistically significant difference was noted between them. In addition, no significant difference in short-term post-operative complications was observed between the two groups.

CONCLUSION: Laparoscopic radical correction with pelvic autonomic nerve preservation for rectal cancer has the same security and feasibility effects as open operation. So it is recommended for wide use in clinics.