Pelvic Autonomic Nerve Preservation Research Articles

Pelvic autonomic nerve preservation in rectal cancer: anatomical concept and clinical significance

Colorectal cancer is one of the most common cancers in the world, and surgery is the mainstage treatment. Urogenital and sexual dysfunction after radical resection of rectal cancer has become an important problem for patients, which seriously affects the quality of life. Some patients give up radical surgery for rectal cancer because of the concerns about sexual and urinary dysfunction. The cause of this problem is intraoperative of injury pelvic autonomic nerve. The preservation of the hypogastric nerve during the surgery is important for the male ejaculation. Pelvic splanchnic nerves are mainly responsible for the male erection. The anatomical origin, distribution, and urogenital function of these two nerves are detailed described in this article. At the same time, this article introduces the classification, key points of the operation and the evaluation of autonomic nerve preservation surgery. With the rapid development of minimally invasive surgery, performing radical surgery for rectal cancer is important, we also need to fully understand the anatomical concept of pelvic autonomic nerves, and apply modern minimally invasive surgical techniques to preserve the patient's pelvic autonomic nerves as well. It is an compulsory course and an important manifestation for the standardization of rectal cancer surgery.

Protective effect of laparoscopic functional total mesorectal excision on urinary and sexual functions in male patients with mid-low rectal cancer

Urinary and sexual dysfunctions are among the most common complications in rectal cancer surgery. This study aimed to investigate the protective effect of laparoscopic functional total mesorectum excision (TME) on urinary and sexual functions in male patients. A total of 248 male patients with mid-low rectal cancer were recruited in this study between February 2017 and July 2020. To overcome selection bias, we performed a 1:1 match using six variables, including age, BMI, ASA score, tumor distance, clinical T stage, and tumor size. The urinary function was assessed by the International Prostate Symptom Score (IPSS), sexual function was assessed by a 5-item version of the International Index of Erectile Function (IIEF-5) and ejaculation grading at postoperative 3 and 12 months. 79 patients received functional TME surgery (FTME group), and 169 patients received routine TME surgery (RTME group). After the propensity score, 79 pairs were balanced and analyzed. Patients in the FTME group showed a lower IPSS score and higher IIEF-5 score than patients in the RTME group at postoperative 3 and 12 months. The incidence of ejaculation dysfunction for patients in the FTME group was lower than patients in the RTME group at postoperative 3 and 12 months. Laparoscopic functional total mesorectal excision was beneficial to faster recovery of urinary and sexual function for patients with rectal cancer, and it could be used as a superior surgical technique for pelvic autonomic nerve preservation in mid-low rectal cancer.

Essential Steps for Optimal Mobilization of Rectum With Pelvic Autonomic Nerve Preservation.

Essential Steps for Optimal Mobilization of Rectum With Pelvic Autonomic Nerve Preservation.

Comparison of postoperative laparoscopic and open total mesorectal excision on lower urinary tract function in men with rectal cancer.

This study investigated male voiding dysfunction (VD) or lower urinary tract function in rectal cancer (RC) patients after laparoscopic or open total mesorectal excision with pelvic autonomic nerve preservation (PANP). One hundred and eighty-seven male RC patients admitted between January 2016 and May 2019 were enrolled in this study, 112 of whom underwent laparoscopic total mesorectal excision (LTME) and 75 underwent open total mesorectal excision (OTME). The International Prostatic Symptom Score (IPSS) was compared between the two groups. The postoperative IPSS in patients with RC was elevated on day 7 and gradually decreased during the first month after surgery. Compared with the OTME group, the IPSS scores decreased less in the LTME group at week 1, and months 1 and 3 postoperatively (6.82 ± 2.13 vs 10.15 ± 3.86, 5.70 ± 2.45 vs 7.21 ± 2.0, and 5.01 ± 2.09 vs 5.75 ± 2.55, respectively; P < 0.05). The VD rate was significantly lower in the LTME group than the OTME group at 1, 2, and 3 weeks postoperatively (21.4% vs 26.8%,13.4% vs 25.3%, and 9.8% vs18.6%, respectively; P < 0.05); however, there was no major difference in the incidence of VD 6months postoperatively between the two groups (P > 0.05). VD was more frequent in the OTME group than the LTME group 6months postoperatively, but the difference was not statistically significant (odds ratio=1.857, 95% CI, 0.964-3.645, P=0.064). LTME may be superior to OTME with respect to PANP of lower urinary tract function in males with RC.

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.

Magnetic resonance neuroimaging promotes the preservation of pelvic autonomic nerves in laparoscopic total mesorectal excision: a comparative study.

BackgroundHow to preserve pelvic autonomic nerves system (PANS) in total mesorectal excision (TME) is still a technical challenge for gastrointestinal surgeons, and nerve preservation according to preoperative magnetic resonance imaging (MRI) is a hot topic in pelvic surgery. The purpose of this study was to assess the postoperative urogenital function of patients with rectal cancer (RC) who underwent preoperative and postoperative neuroimaging of PANS vs. patients who did not.MethodsPatients meeting the inclusion criteria were prospectively enrolled in a magnetic resonance neuroimaging (MRN) group from June 2018, while primary RC patients from January 2016 to May 2018 who met the inclusion criteria were enrolled in a non-MRN group. Patients in the MRN group underwent MRN examination before operation and 6 months after operation, while those in the non-MRN group were collected and analyzed retrospectively.ResultsBased on International Prostate Symptom Score (IPSS) and International Index of Erectile Function 5 (IIEF5) scores at 6 months, the postoperative urinary and sexual function of male patients in the MRN group were significantly better than that in the non-MRN group (P<0.05). In addition, based on International Consultation on Incontinence modular Questionnaire on Female Lower Urinary Tract Symptoms (ICIQ-FLUTS) and Female Sexual Function Index (FSFI) scores at 6 months, the postoperative sexual function of female patients in the MRN group was significantly better than that in the non-MRN group (P<0.05).ConclusionsIn the present study, we constructed a three-dimensional (3D) presentation of PANS based on preoperative MRN which showed in vivo pelvic autonomous innervation. This may promote the preservation of PANS during TME and reduce the postoperative urogenital dysfunction rate.

Surgical Outcomes of Robotic Resection for Sigmoid and Rectal Cancer: Analysis of 109 Patients From a Single Center in China.

Background: Robotic colorectal surgery has been increasingly performed in recent years. The safety and feasibility of its application has also been demonstrated worldwide.However, limited studies have presented clinical data for patients with colorectal cancer (CRC) receiving robotic surgery in China. The aim of this study is to present short-term clinical outcomes of robotic surgery and further confirm its safety and feasibility in Chinese CRC patients.Methods: The clinical data of 109 consecutive CRC patients who received robotic surgery at Sun Yat-sen University Cancer Center between June 2016 and May 2019 were retrospectively reviewed. Patient characteristics,tumor traits, treatment details, complications, pathological details, and survival status were evaluated.Results: Among the 109 patients, 35 (32.1%) had sigmoid cancer, and 74 (67.9%) had rectal cancer. Thirty-seven (33.9%) patients underwent neoadjuvant chemoradiotherapy. Ten (9.2%) patients underwent sigmoidectomy, 38 (34.9%) underwent high anterior resection (HAR), 45 (41.3%) underwent low anterior resection (LAR), and 16 (14.7%) underwent abdominoperineal resection (APR). The median surgical procedure time was 270 min (range 120–465 min). Pathologically complete resection was achieved in all patients. There was no postoperative mortality. Complications occurred in 11 (10.1%) patients, including 3 (2.8%) anastomotic leakage, 1 (0.9%) anastomotic bleeding, 1 (0.9%) pelvic hemorrhage, 4 (3.7%) intestinal obstruction, 2 (1.8%) chylous leakage, and 1 (0.9%) delayed wound union. At a median follow-up of 17 months (range 1–37 months), 1 (0.9%) patient developed local recurrence and 5 (4.6%) developed distant metastasis, with one death due to disease progression.Conclusions: Our results suggest that robotic surgery is technically feasible and safe for Chinese CRC patients, especially for rectal cancer patients who received neoadjuvant treatment. A robotic laparoscope with large magnification showed a clear surgical space for pelvic autonomic nerve preservation in cases of mesorectal edema.

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.

An Optimal Surgical Plane for Laparoscopic Functional Total Mesorectal Excision in Rectal Cancer

BackgroundIntraoperative damage of pelvic autonomic nerves is the primary reason for postoperative sexual and urinary dysfunction after rectal cancer surgery,1,2 especially in patients with low rectal cancer. In the present study, we developed the nerve plane as a novel concept in rectal cancer surgery, which served as a landmark for better preservation of pelvic autonomic nerves in standardized total mesorectal excision (TME) surgery. The nerves never exist alone, and are always surrounded by tiny capillaries and adipose tissue, which are covered by a thin layer of membranous tissue, leading to a continuous plane, which we defined as the nerve plane. The nerve plane could be preserved from thermal damage, ischemic injury, nerve stretching, and chemical factors produced by local inflammatory effects. We also found loose connective tissue (the first gap) between the proper fascial of the rectum and the nerve plane, which was also a natural avascular holy’s plane. Using the concept of nerve plane, the proposed functional TME procedure could help surgeons to better protect pelvic autonomic nerves from injury. Herein, we present a brief video to describe the technical aspects of a laparoscopic functional TME in rectal cancer surgery. MethodsFifty-eight consecutive male patients without preoperative sexual and urinary dysfunction underwent laparoscopic functional TME surgery for histologically confirmed adenocarcinoma at our hospital since 2018. The present study was approved by the institutional review board of the Renmin Hospital of Wuhan University (2018-X-08), and written informed consent was obtained from all patients. Urinary and sexual function was evaluated using the international prostatic symptom score (IPSS)3 and the 5-item version of International Index of Erectile Function (IIEF-5)4 questionnaires, respectively, which are internationally recognized as well-structured and reliable questionnaires to evaluate urinary and sexual function. Moderate-to-severe urinary dysfunction was defined as IPSS score >8 points,2 while erectile dysfunction was defined as IIEF-5 score ≤ 11points.5 The laparoscopic functional TME procedure shown in the video is described as follows. First, the incision line was marked on the peritoneum from the lower edge of the duodenum to the pelvic entrance with an electric hook using a medium approach. The holy’s plane was divided into five structures by enforcing traction and anti-traction, which included fascia propria of the rectum, the loose areolar connective tissue over the nerve plane (the first gap), the nerve plane, the loose areolar connective tissue below the nerve plane (the second gap), and the Gerota’s fascia or the presacral fascia. Second, dissection over the nerve plane was performed from the lower edge of the duodenum to the pelvic entrance. Superior hypogastric plexus nerve plane, abdominal aortic plexus nerve plane, and inferior mesenteric plexus nerve plane were clearly displayed. Dissection was continued in this way, and the left and right hypogastric nerve planes were also preserved. Finally, the pelvic cavity was entered, and posterior dissection was continued downward to the Waldeyer fascia. We selected to go over the Waldeyer fascia along the nerve plane instead of transecting it to enter the superior levator space, thereby some small nerves such as efferent branches of hypogastric nerves in this area were protected from injury. The lateral pelvic dissection was continued over the pelvic plexus nerve plane, anterior pelvic dissection was continued, and the Denonvillier’s interfascial space was entered between the anterior layer and the posterior layer of Denonvilliers’ fascia. The left and right neurovascular bundles (NVB) were avoided and not intentionally exposed during the operation, thereby protecting them from injury. Although some steps of the procedure are displayed very close to the anatomical landmarks, patience and higher-resolution laparoscopic equipment are needed for surgeons to find the nerve plane. For less experienced surgeons, we suggest that the harmonic with the “hot” blade should be as far away from the nerves as possible during the radical resection of tumor. After the rectum was dissected, superior hypogastric plexus nerve plane, abdominal aortic plexus nerve plane, inferior mesenteric plexus nerve plane, hypogastric nerve plane, pelvic plexus nerve plane, left ureter, and genital vessels were displayed and completely preserved. The intraoperative nerve plane and mesorectum of the postoperative specimen were intact and smooth. ResultsThe median age of patients was 53 years, with a body mass index (BMI) of 24.0 kg/m2. The median total operation time was 198 min (range 128–248 min). The median volume of blood loss was 30 ml (range 10–50 ml). The median number of retrieved lymph nodes was 31 (range 13–65). No patient showed postoperative moderate-to-severe urinary dysfunction at 6 months. The incidence of postoperative erectile dysfunction was 5.17% (3/58) at 12 months. No patient was lost during 1-year of follow-up. ConclusionNerve plane is an optimal surgical landmark for laparoscopic functional total mesorectal excision in rectal cancer. It provides a superior surgical technique for pelvic autonomic nerve protection.

Anatomy research on Denonvilliers fascia and its significance in nerve-preservation rectal cancer surgery

Urinary and sexual dysfunctions due to intraoperative pelvic autonomic nerve injury have become the most common complications of rectal cancer surgery, seriously affecting postoperative quality of life. How to protect the nerve and urogenital function while ensuring radical resection for rectal cancer has become the focus of research. We previously carried out a series of systematic studies on Denonvilliers fascia, an important anatomical structure closely related to protection of pelvic autonomic nerve, and demonstrated the importance of Denonvilliers fascia in preservation of intraoperative pelvic autonomic nerve and protection of postoperative urogenital function from aspects of anatomy, physiology, tissue, operation practice and so on. Meanwhile, based on the interim results of our multicenter randomized controlled study, we confirmed that total mesorectal excision with preservation of Denonvilliers fascia (innovative TME, iTME) could effectively reduce the incidence of postoperative urinary and sexual dysfunctions in male patients with mid-low rectal cancer, without sacrificing oncologic outcome. In this article, combined with our research results, we review the literature on anatomy research progress of Denonvilliers fascia to demonstrate the significance and research prospect of Denonvilliers fascia in the pelvic autonomic nerve preservation surgery for rectal cancer.

Risk factors for sexual dysfunction after rectal cancer surgery in 948 consecutive patients: A prospective cohort study

BackgroundSexual dysfunctions seriously affect the quality of life of patients. The aim of this study was to identify the risk factors for sexual dysfunction after rectal cancer surgery. MethodsA total of 948 consecutive patients undergoing rectal cancer radical resection were included between January 2012 and August 2019. The sexual functions were evaluated by the 5-item version of the International Index of Erectile Function (IIEF-5) in men and Index of Female Sexual Function (IFSF) in women at 12 months postoperatively. ResultsPostoperative sexual dysfunction was observed in 228 patients with rectal cancer (24.05%), which included 150 cases in male patients (25.0%) and 78 cases in female patients (22.5%). A multivariate logistic regression analysis results showed that age ≥45 years old (OR = 1.72, p = 0.001), tumor below the peritoneal reflection (OR = 1.64, p = 0.005), receiving preoperative radiotherapy (OR = 4.12, p < 0.001) and undergoing abdominoperineal resection (APR), intersphincteric resection (ISR) and Hartmann surgery (OR = 2.43, p < 0.001) were the independent risk factors of sexual dysfunction for patients with rectal cancer. ConclusionAge ≥45 years old, tumors below the peritoneal reflection, receiving preoperative radiotherapy, and undergoing APR, ISR and Hartmann surgery were the independent risk factors of sexual dysfunction. Patients should be informed about the sexual dysfunctions in the pre-operative consultations. More attention should be paid to intraoperative pelvic autonomic nerve preservation on rectal cancer patients with these risk factors for clinic surgeons.

Site-specific risk factors for local recurrence after rectal cancer surgery

BackgroundQuite few studies examined risk factors for local recurrence after rectal cancer surgery with respect to local recurrence sites. MethodsLocal recurrence sites were categorized into axial, anterior, posterior, and lateral (pelvic sidewall), and axial, anterior, and posterior type were combined as the “other” type of local recurrence. Among 76 patients enrolled into our prospective randomized controlled trial to determine the indication for pelvic autonomic nerve preservation (PANP) in patients with advanced lower rectal cancer (UMIN000021353), multivariate analyses were conducted to elucidate risk factors for either lateral or the “other” type of local recurrence. ResultsUnivariate analyses showed that tumor distance from the anal verge was significantly (p = 0.017), and type of operation (sphincter preserving operation (SPO) vs. abdominoperineal resection (APR)) was marginally (p = 0.065) associated with pelvic sidewall recurrence. Multivariate analysis using these two parameters showed that tumor distance from the anal verge was significantly and independently correlated with pelvic sidewall recurrence (p = 0.017). As for the “other” type of local recurrence, univariate analyses showed that depth of tumor invasion (p = 0.011), radial margin status (p < 0.001), and adjuvant chemotherapy (p = 0.037) were significantly associated, and multivariate analysis using these three parameters revealed that depth of tumor invasion (p = 0.004) and radial margin status (p < 0.001) were significantly and independently correlated with the “other” type of local recurrence. ConclusionRisk factors for local recurrence after rectal cancer surgery were totally different with respect to the intra-pelvic recurrent sites. Site-specific probability of local recurrence can be inferred using these risk factors. Trial registration numberUMIN000021353.

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

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. 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. 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. 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.

Long-term Voiding and Sexual Function in Male Patients After Robotic Total Mesorectal Excision With Autonomic Nerve Preservation for Rectal Cancer: A Cross-Sectional Study.

Robotic surgery can help to identify and preserve the autonomic nerves during total mesorectal excision (TME) compared with open surgery or laparoscopy due to the 3-dimensional image and high dexterity of the robotic system. Therefore, this study aimed to assess voiding and sexual function after robotic TME with autonomic nerve preservation. In particular, we focused on the long-term results in male patients operated by a single experienced surgeon. We surveyed male patients aged 50 years and below at the time of robotic rectal cancer surgery between November 2011 and July 2018. Patients who died and those who had a recurrence and underwent abdominoperineal resection were excluded. The questionnaire covered the International Prostate Symptom Score (IPSS) and the 5-item version of the International Index of Erectile Function (IIEF-5) for voiding and sexual function, respectively. Thirty-nine patients (median age, 44 y) were surveyed. IPSS and IIEF-5 scores were 5.7±5.3 and 14.7±8.4, respectively. Only 6 patients (15.4%) complained of poor quality of life due to their urinary symptoms. In sexual function, 10 patients (25.6%) complained severe reduction compared with their preoperative status. The average of postoperative days defined from surgery to the questionnaire was 37.8 months. A significant change in the IIEF-5 score was observed between 1 and 2 years postoperatively (5.8±6.9 vs. 16.5±8.8; P=0.027). As we only included male patients who were operated by a single experienced surgeon, the results of robotic TME with pelvic autonomic nerve preservation showed acceptable data in preserving both voiding and sexual functions. Although related clinical factors for poor functional outcomes was not statistically significant due to the small sample size, we could observe an improvement in sexual function between 1 and 2 years after surgery with long-term functional results.

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

BackgroundThe 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.MethodsFive 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.ResultsThe 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.ConclusionIdentification 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.

Efficiency analysis on functional protection of nerve plane-oriented laparoscopic total mesorectal excision

Objective: Using previous total mesorectal excision with pelvic autonomic nerve preservation (PANP+TME) and simple total mesorectal excision (TME) without emphasis on retained nerves as control, we explore the advantages of nerve plane-oriented laparoscopic total mesorectal excision (NPO+LTME) on urinary and sexual function. Methods: A retrospective cohort study was carried out. Case inclusion criteria: (1) male patients with pathologically confirmed middle and low rectal adenocarcinoma (4 to 11 cm from the anus); (2) stage T1-2tumor; (3) normal sexual life before operation. Exclusion criteria: (1) no pathological diagnosis before surgery; (2) local recurrence or distant metastasis; (3) preoperative neoadjuvant chemoradiotherapy; (4) opensurgery and laparoscopic surgery conversionto open; (5) no follow-up data. According to the above criteria, clinical data of 173 male patients with low and middle rectal adenocarcinoma who underwent radical operation for laparoscopic rectal cancer from July 2003 to July 2018 at the Department of Gastrointestinal Surgery, Wuhan University People's Hospital were collected. According to different surgical methods, patients were divided into TME group (58 cases), PANP+TME group (63 cases) and NPO+LTME group (52 cases). There were no significant differences in the baseline data including age, body mass index and pathological examination between the 3 groups (all P>0.05). The nerve plane referred to the nerve, the adipose tissue, the extremely finecapillaries around the nerve with overlying fine membranous tissue. NPO+LTME referred to the process of laparoscopic TME guided by the nerve plane, performing in the loose connective tissue between the nerve plane and the rectal properfascia, in order to ensure the integrity of the nerve plane, and maximally protect the patient's urinary and reproductive functions. The operation time, intraoperative blood loss, urinary catheter removal time, urinary function grading, postoperative first erection time, and erectile function and ejaculation function were observed and compared among the 3 groups at 3- and 6-month after operation. Results: In the NPO+LTME group, the PANP+TME group and the TME group, the operation time was (181.9±24.5) minutes, (176.7±29.2) minutes and (137.7±16.2) minutes, respectively (F=54.868, P<0.001); the intraoperative blood lost was (6.0±1.4) ml, (6.5±1.8) ml and (12.8±4.6) ml, respectively (F=95.016, P<0.001); the time to postoperative removal of the catheter was (2.4±1.1) days, (3.7 ±1.7) days and (6.5±2.4) days, respectively (F=79.409, P<0.001); the first postoperative erection time was (1.6±0.6) days, (8.9±2.7) days and (15.9±6.8) days (F=177.677, P<0.001), respectively, whose differences were all statistically significant (all P<0.01). In comparison of urinary function grading, the proportion of grade I (normal function, no urinary dysfunction) in the NPO+LTME, the ANP+TME group and the TME group was 84.1% (53/63), 39.7% (23/58) and 19.2% (10/52), respectively, and the difference was statistically significant (H=52.915, P<0.001). At postoperative 3- and 6-month, proportion of patients with grade I erectile function (normal erectile function) was 77.8% (49/63) and 85.7% (54/63), 44.8% (26/58) and 53.4% (31/58), 28.8% (15/52) and 48.1% (25/52) in the NPO+LTME group, the PANP+TME group, and the TME group, respectively. The differences were statistically significant (H=91.709, P<0.001; H=79.692, P<0.001). The proportion of patients with grade I ejaculation function (with ejaculation, no abnormalities in routine semen examination before and after surgery) at 3- and 6-month after surgery in the NPO+LTME group, the PANP+TME group and the TME group was 82.5% (52/63) and 87.3% (55/63), 53.4% (31/58) and 60.3% (35/58), 28.8% (15/52) and 46.1% (24/52), respectively. The differences were statistically significant as well (H=86.543, P<0.001; H=78.667, P<0.001). Patients in the NPO+LTME group had no grade III erections and ejaculation disorders. Conclusion: The surgical procedure of NPO+LTME can promote the recovery of postoperative neurological function and preserve urination and sexual function better.

Application value of fascia orientation in lateral lymph node dissection of low rectal cancer

Lateral lymph node metastasis is an important pathway for metastasis of low rectal cancer, which is also one of the most important risk factors for bad prognosis. Numerous evidences from evidence-based medicine demonstrate that both preoperative and postoperative chemoradiotherapy cannot eradicate lateral lymph node metastasis. Since selective resection of lateral lymph nodes with tumor residue after chemoradiotherapy can significantly decrease local recurrence rate and improve cancer prognosis, it is the only treatment modality for these patients to achieve disease-free survival. However, because of the narrow space, complicated anatomy and dense vessels and nerves of lateral area around rectum, lateral lymph node dissection (LLND) has many problems, such as long operation time, excessive intraoperative bleeding, piecemeal resection of lymphoid issue and high morbidity of postoperative complications, which restrict the clinical promotion of LLND. With the development in the study of fascia anatomy, surgeons are gradually familiarized with the perirectal fascia. Partitioning rectal lateral space and performing LLND based on fascia orientation can provide clear surgical plane and dissection boundary. Furthermore, it can avoid insufficient and excessive resection. Moreover, resecting tissue along fascia structure can avoid entering lymph tissue and prevent dissemination of malignant cells. Meanwhile, it can reduce exudation and bleeding, and present better pelvic autonomic nerve preservation. LLND based on fascia orientation is more in line with the concept of modern anatomy, more efficient both in tumor radical resection and function protection, and contributes to the promotion and quality control of LLND.

Intraoperative monitoring of pelvic autonomic nerves during laparoscopic low anterior resection of rectal cancer.

BackgroundSome patients with low rectal cancer experience anorectal and urogenital dysfunctions after surgery, which can influence the long-term quality of life. In this study, we aimed to protect nerve function in such scenarios by performing intraoperative monitoring of pelvic autonomic nerves (IMPAN).Patients and methodsWe retrospectively investigated a series of 87 patients undergoing laparoscopic low anterior resection of rectal cancer. Nerve-sparing was evaluated both visually and electrophysiologically. IMPAN was performed by stimulating the pelvic autonomic nerves under processed electromyography of the internal anal sphincter. Urination, defecation, sexual function, and the quality of life were evaluated using validated and standardized questionnaires preoperatively and at follow-up, 12 months after surgery.ResultsAmong a total of 87 patients (53 male and 34 female patients), IMPAN with simultaneous electromyography of the internal anal sphincter was performed in 58 (66.7%) patients. Bilateral positive IMPAN results for both measurements, indicating successfully confirmed pelvic autonomic nerve preservation, were obtained in 45 (51.7%) patients. No significant difference was found in terms of urogenital and anorectal functions between preoperative and postoperative patients with bilateral positive IMPAN (P>0.05). Compared to preoperative patients with IMPAN (unilateral) or without IMPAN, these patients exhibited higher International Prostate Symptom Score, a lower International Index of Erectile Function-5, and a lower Female Sexual Function Index score at 12 months postoperatively (P<0.05).ConclusionIMPAN is an appropriate method with which to laparoscopically protect nerve function.

Recognition of the gist of laparoscopic sphincter-preserving surgery in ultra-low rectal cancer

The laparoscopic technique has been applied for over 20 years and its superiority of minimally invasive surgery has been enlarged after combining with 3D technology. Application of this minimally invasive technology is widely acknowledged in rectal cancer surgery, especially in ultra-low rectal cancer. The surgeons can have a good view of the structure such as nerves, fascia in pelvic cavity sufficiently with the help of high definition vision, and recognize that not only the configuration of anus should be preserved but also its function. Therefore, a higher requirement on operative skill is made to the surgeons. In this article, based on our experience and realization, we reconsider and review the key technology of laparoscopic anus-preserving surgery in ultra-low rectal cancer from the aspects of vessel handling, retrorectal space mobilization, pelvic autonomic nerve preservation and intersphincteric groove management, aiming to promote standard treatment, and at the same time, to result in benefits for more patients with ultra-low rectal cancer.

Robot-guided neuromapping during nerve-sparing taTME for low rectal cancer.

Intraoperative pelvic neuromapping with electrophysiological evaluation of autonomic nerve preservation during robotic total mesorectal excision (TME) for rectal cancer is conventionally performed by the bedside assistant with a hand-guided probe. Our goal was to return autonomy over the neuromonitoring process to the colorectal surgeon operating the robotic console. A recently described prototype microfork electrostimulation probe was evaluated intraoperatively during abdominal robotic-assisted transanal TME (taTME) surgery for low rectal cancer in three consecutive male patients. An intraoperative video demonstrates the good control and maneuverability of the prototype probe with electrophysiological confirmation of bilateral pelvic autonomic nerve preservation. This study presents the first in situ application of a new microfork probe for fully robot-guided neuromapping in three patients undergoing TME surgery for low rectal cancer.