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.

[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.

Evaluation of effect of robotic versus laparoscopic surgical technology on genitourinary function after total mesorectal excision for rectal cancer.

OBJECTIVE: Because the recovery of genitourinary function after total mesorectal excision (TME) is affected by multiple factors, the role of robot-assisted TME technology in postoperative function in previous studies is still controversial. Our study aimed to evaluate the impact of robotic technology on the recovery of genitourinary function after TME for rectal cancer by analysing the correlations between influencing factors of genitourinary function and robotic surgery. METHODS: Between January 2017 and January 2020, patients with rectal cancer (cT1-3NxM0) were registered. Genitourinary function was assessed by the International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) test, Female Sexual Function Index (FSFI) and urodynamic examination before surgery and 1, 3, 6, and 12 months postoperatively. Genitourinary function was compared between the laparoscopic total mesorectal excision (L-TME) and robotic total mesorectal excision (R-TME) groups, and the correlative factors associated with postoperative genitourinary function were analysed using the generalized estimated equation (GEE). RESULTS: Compared with L-TME, R-TME showed a superior IPSS, voiding volume, residual urine volume and IIEF score during the early postoperative period. According to the GEE analysis, postoperative genitourinary function was positively correlated with laparoscopic anterior resection/abdomen perineal resection (LAR/APR) but negatively correlated with tumour size, tumour distance to anus, TNM, adjuvant chemotherapy, adjuvant radiotherapy, complete TME, circumferential resection margin (CRM), blood loss, diverting stoma, conversion, and anastomotic leakage. CONCLUSION: Due to the important role of robotic surgical technology on the influential factors of postoperative genitourinary function and the superiority of identifying and preserving autonomic nerves, robotic technology is conducive to the early recovery of postoperative urogenital function while adhering to oncological dissection principles. No significant difference was found between the da Vinci R-TME and MicroHand R-TME groups.

[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.

Identification of the surgical indication line for the Denonvilliers' fascia and its anatomy in patients with rectal cancer.

BACKGROUND: The high rate of urogenital dysfunction after traditional total mesorectal excision (TME) has caused doubts among scholars on the standard fashion of dissection. We have proposed the necessity to preserve the Denonvilliers' fascia in patients with rectal cancer. However, how to accurately locate the Denonvilliers' fascia is unclear. This study aimed to explore anatomical features of the Denonvilliers' fascia by comparing autopsy findings and observations of surgical videos so as to propose a dissection method for the preservation of pelvic autonomic nerves during rectal cancer surgery. METHODS: Five adult male cadaver specimens were dissected, and surgical videos of 135 patients who underwent TME for mid-low rectal cancer between January 2009 and February 2019 were reviewed to identify and compare the structure of the Denonvilliers' fascia. RESULTS: The monolayer structure of the Denonvilliers' fascia was observed in 5 male cadaver specimens, and it was located between the rectum, the bottom of the bladder, the seminal vesicles, the vas deferens, and the prostate. The Denonvilliers' fascia was originated from the rectovesical pouch (or rectum-uterus pouch), down to fuse caudally with the rectourethral muscle at the apex of the prostate, and fused to the lateral ligaments on both sides. The fascia was thinner on the midline with a thickness of 1.06 ± 0.10 mm. The crown shape of the Denonvilliers' fascia was slightly triangular, with a height of approximately 5.42 ± 0.16 cm at midline. Nerves were more densely distributed in front of the Denonvilliers' fascia than behind, especially on both sides of it. Under laparoscopic view, the Denonvilliers' fascia was originated at the lowest point of the rectovesical pouch (or rectum-uterus pouch), with a thickened white line which was a good mark for identifying the Denonvilliers' fascia. CONCLUSION: Identification of the surgical indication line for the Denonvilliers' fascia could help us identify the Denonvilliers' fascia, and it would improve our ability to protect the pelvic autonomic function of patients undergoing TME for rectal cancer.

Pelvic autonomic nerve preservation in radical rectal cancer surgery: changes in the past 3 decades.

The advent of total mesorectal excision (TME) together with minimally invasive techniques such as laparoscopic colorectal surgery and robotic surgery has improved surgical results. However, the incidence of bladder and sexual dysfunction remains high. This may be particularly distressing for the patient and troublesome to manage for the surgeon when it does occur. The increased use of neoadjuvant and adjuvant radiotherapy is also associated with poorer functional outcomes. In this review, we evaluate current understanding of the anatomy of pelvic nerves which are divided into the areas of the inferior mesenteric artery pedicle, the lateral pelvic wall and dissection around the urogenital organs. Surgical techniques in these areas are discussed. We also discuss the results in functional outcomes of the various techniques including open, laparoscopic and robotic over the last 30 years.