The incidence of rectal cancer is increasing worldwide, and surgery remains the primary treatment modality. With the advent of total mesorectal excision (TME) technique, the probability of tumor recurrence post-surgery has significantly decreased. Surgeons' focus has gradually shifted towards minimizing the impact of surgery on urinary and sexual functions. Among these concerns, the optimal dissection of the rectal lateral ligaments and preservation of the pelvic floor neurovascular bundle have become critical. To explore the optimal surgical technique for TME and establish a standardized surgical protocol to minimize the impact on urinary and sexual functions, we propose the eight-zone dissection strategy for pelvic floor anatomy.

To compare the differences in surgical specimen integrity and postoperative quality of life satisfaction between the traditional pelvic floor dissection strategy and the innovative eight-zone dissection strategy.

We analyzed the perioperative data of patients who underwent laparoscopic radical resection of rectal cancer at Qilu Hospital of Shandong University between January 1, 2021 and December 1, 2023. This study included a total of 218 patients undergoing laparoscopic radical surgery for rectal cancer, among whom 109 patients underwent traditional pelvic floor dissection strategy, and 109 patients received the eight-zone dissection strategy.

There were no significant differences in general characteristics between the two groups. Patients in the eight-zone dissection group had higher postoperative specimen integrity (88.1% vs 78.0%, P = 0.047). At the 3-month follow-up, patients in the eight-zone surgery group had better scores in urinary issues (6.8 ± 3.3 vs 5.3 ± 2.5, P = 0.045) and male sexual desire (2.2 ± 0.6 vs 2.5 ± 0.5, P = 0.047) compared to the traditional surgery strategy group.

This study demonstrates that the eight-zone dissection strategy for laparoscopic lateral ligament dissection of rectal cancer is safe and effective. Compared with the traditional pelvic floor dissection strategy, this approach can reduce the risk of nerve injury and minimize the impact on urinary and sexual functions. Therefore, we recommend the clinical application of this strategy to better serve patients with rectal cancer.

The primary goal of surgical intervention for rectal cancer is to achieve an oncologic cure while preserving function. Since the introduction of total mesorectal excision (TME), the oncologic outcome has improved greatly in terms of local recurrence and cancer-specific survival. However, there are still concerns regarding functional outcomes such as sexual and urinary dysfunction, even among experienced colorectal surgeons. Intraoperative nerve damage is the primary reason for sexual and urinary dysfunction and occurs due to lack of anatomical knowledge and poor visualization of the pelvic autonomic nerves. The rectum is located concavely along the curved sacrum and both the ischial tuberosity and iliac wing limit the pelvic cavity boundary. Thus, pelvic autonomic nerve preservation during dissection in a narrow or deep pelvis, with adherence to the TME principles, is very challenging for colorectal surgeons. Recent developments in robotic technology enable overcoming these difficulties caused by complex pelvic anatomy. This system can facilitate better preservation of the pelvic autonomic nerve and thereby achieve favorable postoperative sexual and voiding functions after rectal cancer surgery. The nerve-preserving TME technique includes identification and preservation of the superior hypogastric plexus nerve, bilateral hypogastric nerves, pelvic plexus, and neurovascular bundles. Standardized procedures should be performed sequentially as follows: posterior dissection, deep posterior dissection, anterior dissection, posterolateral dissection, and final circumferential pelvic dissection toward the pelvic floor. In future perspective, a structured education program on nerve-preserving robotic TME should be incorporated in the training for minimally invasive surgery.

To inspect Denonvilliers' fascia and its relationship with neighboring oncologically and functionally important anatomic structures by laparoscopic approach.

A total of 112 patients with middle or low rectal cancer were successfully treated by laparoscopic total mesorectal excision (TME). Digital versatile disk (DVD) recordings were retrieved for scrutiny of the whole dissection process of Denonvilliers' fascia and its contiguous anatomic structures.

As highlighted in the attached video footage, for nearly all male patients (91%, n = 58), the boundaries of Denonvilliers' fascia could be clearly recognized by laparoscopy. Denonvilliers' fascia, varying in nature from a fragile translucent fibrous layer to a tough leathery membrane, manifests itself as a trapezoidal "apron" covering the glistening fatty tissues of the anterior mesorectum. Anterior dissection in TME can be efficiently continued downwards "in front of" Denonvilliers' fascia. When the prostate is reached, the natural surgical plane halts, and the dissection plane should be shifted to behind this fascia. In contrast, in female patients, Denonvilliers' fascia was much less obvious as a distinct fibrous layer than in male patients. The most appropriate term for the structure in between the rectum and vagina may be rectovaginal septum, in which there is no natural surgical plane, rather than Denonvilliers' fascia.

By laparoscopic approach, the nature of Denonvilliers' fasciae in male and female patients can be better defined and facilitates more precise laparoscopic total mesorectal excision for rectal cancer.

This is a phase II study, the aim of which is to determine if a laparoscopic approach can be used in pelvic autonomic nerve-preserving surgery for patients with lower rectal cancer following chemoradiation therapy.

Patients with T3 lower rectal cancer treated by preoperative chemoradiation were recruited and subjected to laparoscopic pelvic autonomic nerve-preserving surgery with total mesorectal excision and a sphincter-saving procedure. This study was performed with the approval of the ethics committee of National Taiwan University Hospital. Because the quality of a surgical trial is highly dependent on the skill of the surgeon with respect to the technique under study, it is imperative that a surgical trial only be implemented after the surgical technique has been judged to be mature. Before the start of this clinical trial, we gained a sound knowledge of surgical anatomy through conventional open surgery for rectal cancer and mastered the related laparoscopic skills from other sound and proven laparoscopic approaches, including right hemicolectomy, left hemicolectomy, among others. We determined that the learning curve for this surgical technique necessitated that colorectal surgeons carry out at least 20 such procedures. At this point we conducted this clinical trial. The details of the surgical procedures have been shown in the attached video. Briefly, the dissection commences at the pelvic promontory with exposure and preservation of the superior hypogastric plexus. The pre-aortic plexus and inferior mesenteric plexus are preserved by sparing the pre-aortic connective tissue and leaving a 1- to 2-cm-long stump of the inferior mesenteric artery in situ. Subsequently, the "holy plane" at the transition of the mesosigmoid to the mesorectum is meticulously dissected to progressively displace the hypogastric nerves dorsally and laterally and, therefore, preserving them. Following adequate dorsal and lateral dissection down to the floor of the pelvis, the so-called lateral ligament is reached at which the mesorectum appears to be adherent, anteriorly and laterally, to the inferior hypogastric plexus (at roughly 10:00-2:00 O'clock or within an angle of 60 degrees about symphysis on both sides). The ligaments are divided immediately at the endopelvic fascia of the mesorectum to avoid damage to the inferior hypogastric plexus (pelvic plexus). Finally, great care was taken to dissect the lateral border of Denonvilliers' fascia where the inferior hypogastric plexus joins the neurovascular bundle described by Walsh. Postoperatively, only patients successfully operated on by total pelvic autonomic nerve-preserving surgery were included in the statistical analysis of surgical outcomes. Preoperatively, all patients were screened for their genitourinary function by a questionnaire-based interview. Patients with abnormal preoperative baseline functional data were excluded from further postoperative assessment of sexual or urinary function. The male sexual function was evaluated by potency and ejaculation. In female patients, the sexual function was assessed by vaginal lubrication, dyspareunia, sexual arousal, and orgasm. The reason for these four parameters is because the influence of pelvic autonomic nerve damage on female sexual function has been ambiguous but would most likely result in impairment of vaginal lubrication and congestion of the genitals. We evaluated sexual function at 6 months postoperatively, when the temporary colostomy had been closed and the patients were completely recovered from surgical disability. In evaluating urinary function, the duration between initial voiding trial and spontaneous voiding was recorded. The questionnaire used for the assessment of urinary dysfunction was based on the International Prostate Symptom Score and the following parameters from this Score were used: incomplete emptying, frequency, intermittency, urgency, week stream, straining, and nocturia. Any voiding problems recovered within 3 months after the operation were considered to be transient bladder voiding dysfunction; all other voiding problems were deemed persistent. The interview and scoring of the questionnaire were done by the research assistant blinded to operation procedures. The genitourinary function was ranked as good, fair (decreased), and poor (impaired).

Between June 2003 and December 2005, a total of 98 patients (stage II: n = 44; stage III: n = 54; male: n = 50; female: n = 48) were enrolled in this study. Technically, although the dissection plane is a little blurred by preoperative chemoradiation therapy, the laparoscopic pelvic nerve-preserving procedure with total mesorectal excision was successfully performed in 89 (90.8%) patients with an acceptable operation time (284.4 +/- 44.8 minutes; mean +/- standard deviation) and little blood loss (114.5 +/- 24 ml). The number of dissected lymph nodes was 16.4 +/- 4.0. With respect to scrutiny of surgical specimens, the distal safety margin was adequate (mean: 2.4 cm; range: 1.2-5.6 cm), and the circumferential resection margins were free of tumor invasion (mean: 8.6 mm; range: 2-18 mm). A total of 74 patients completed the evaluation of urinary function. For these 74 patients, the median duration of training for the Foley catheter was 7 days (range: 4-64 days). The voiding function after removal of the Foley catheter were good in 53 (71.6%) patients, fair in 17 (23.0%), and poor in four (5.4%). Of the 17 patients with fair bladder function, eight were transient dysfunction and recovered thereafter. Thirty-two male and 28 female patients who were sexually active before the operation responded to the assessment of sexual function. In male patients, the ejaculation was good in 18 (56.3%) patients, fair (decrease in ejaculatory amounts) in six (18.7%), and poor (retrograde ejaculation, failure to ejaculate) in eight (25%). The potency was good in 20 (62.5%) patients, fair in five (15.6%), and poor in seven (21.9%). In female patients, the sexual function was good in 15 (53.6%) patients, fair in four (14.3%), and poor in nine (32.1%). Specific sexual problems in women included lubrication (46.6%, n = 13), dyspareunia (39.2%, n = 11), sexual arousal (28.6%, n = 8), and orgasm in (32.1%, n = 9).

By the laparoscopic approach, total preservation of pelvic autonomic nerves without compromise of the radical extirpation of tumor is technically feasible in the vast majority of patients with lower rectal cancer who have undergone concurrent chemoradiation therapy, thus facilitating the retention of genitourinary function in a significant proportion of such patients.

Rectal excision is associated with a risk of autonomic nerve damage and associated sexual dysfunction (SD). The evolution of our understanding of the anatomy and physiology of sexual function together with continual refinement of surgery for both benign and malignant disease has led to a decrease in the incidence of SD after rectal surgery. A knowledge of the degree of risk of postoperative SD is important both for the patient and as a benchmark for audit of individual colorectal practice.

The available literature on the anatomy, physiology and surgical aspects of this topic has been researched through the Medline database. The more recently available data are reviewed in the context of the historical evolution of surgery for benign and malignant rectal disease.

In the best hands, permanent impotence occurs in less than 2% of patients following restorative proctocolectomy and at a similarly low rate after proctocolectomy and ileostomy. Isolated ejaculatory dysfunction is also numerically a minor problem post operation for benign disease. Patient age is the most important predictor of SD after surgery for rectal cancer. The incidence of permanent impotence remains high (>40%) after abdomino-perineal excision of the rectum (APE) but the continued decline in the use of this operation in favour of low anterior resection (LAR), which carries about half the risk of impotence compared to sphincter ablating surgery, is likely to have resulted in a fall in the absolute number of patients rendered impotent as a result of rectal cancer surgery. Anatomical dissection of the pelvis with preservation of the named autonomic fibres results in a low and predictable rate of sexual morbidity. Surgeons could profitably spend more time with their patients discussing the possible effects of surgery on sexual function. Further research is required to determine the effects of adjuvant therapy for rectal cancer on sexual function.