Effect of preservation of Denonvilliers' fascia during laparoscopic resection for mid-low rectal cancer on protection of male urinary and sexual functions

Preservation versus resection of Denonvilliers' fascia in total mesorectal excision for male rectal cancer: follow-up analysis of the randomized PUF-01 trial

Traditional total mesorectal excision (TME) for rectal cancer requires partial resection of Denonvilliers' fascia (DVF), which leads to injury of pelvic autonomic nerve and postoperative urogenital dysfunction. It is still unclear whether entire preservation of DVF has better urogenital function and comparable oncological outcomes. We conducted a randomized clinical trial to investigate the superiority of DVF preservation over resection (NCT02435758). A total of 262 eligible male patients were randomized to Laparoscopic TME with DVF preservation (L-DVF-P group) or resection procedures (L-DVF-R group), 242 of which completed the study, including 122 cases of L-DVF-P and 120 cases of L-DVF-R. The initial analysis of the primary outcomes of urogenital function has previously been reported. Here, the updated analysis and secondary outcomes including 3-year survival (OS), 3-year disease-free survival (DFS), and recurrence rate between the two groups are reported for the modified intention-to-treat analysis, revealing no significant difference. In conclusion, L-DVF-P reveals better postoperative urogenital function and comparable oncological outcomes for male rectal cancer patients.

The status of low anterior resection syndrome: data from a single-center in China

AIM

The incidence and risk factors of low anterior resection syndrome (LARS) largely variate in different studies. In addition, there is lack of study on how patients evaluate the therapeutic effect of LARS. This single-center retrospective study aims to investigate the status of LARS in Chinese patients undergoing laparoscopic low anterior resection (LAR).

METHODS

Consequent patients undergoing laparoscopic LAR and free from disease recurrence from January 2015 to May 2021 were issued with both LARS questionnaire and satisfaction survey. Related data were collected and analyzed.

RESULTS

Both LARS questionnaires and self-made satisfaction survey were received from 261 eligible patients. The overall incidence of LARS was 47.1% (minor in 19.5%, major in 27.6%), decreased with the passage of postoperative time (64.7% within 12 months, and 41.7% within 12-36 months), and became stable 36 months later (39.7%). The most common symptoms were defecation clustering (n = 107/261, 41.0%) and defecation urgency (n = 101/261, 38.7%). According to the multivariable regression analysis, risk factors of major LARS were: 1 year increase in age (OR 1.035, 95% CI 1.004-1.068), protective stoma (OR 2.656, 95% CI 1.233-5.724) and T_3 - 4 stage (OR 2.449, 95% CI 1.137-5.273). Most patients complained defecation disorder (87.3%) to doctors and 84.5% got suggestions or treatments for it. However, only 36.8% patients thought the treatments worked for them.

CONCLUSIONS

LARS frequently occurs after laparoscopic LAR, while the therapeutic effect is not satisfying. Elder, advanced T-stage and protective stoma were risk factors for postoperative major LARS.

An Open-Book Approach to Pelvic Dissection for the Male Genitourinary System

Cadaveric dissections of the male pelvis are predominately conducted using either an anterior approach with the pelvis intact, or via pelvic hemi-section. The anterior approach leaves more tissue in-situ, but has limited visualization of retropubic structures, such as the prostate, seminal vesicles, vas deferens, and urethra. Hemi-section of the pelvis provides increased visualization at the expense of transecting midline structures. This article describes a novel cadaveric dissection, which offers enhanced visualization of pelvic structures in-situ. Using a posterior approach, the pelvis was dissected in an "open-book" manner, which fully exposed the posterior aspects of the prostate, seminal vesicles, ureters, and vas deferens. The delicate neurovascular bundle supplying these structures remained undisturbed. The visualization provided by this dissection correlated well with a coronal MRI of the pelvic region. This open-book dissection provides a novel posterior vantage point of the male genitourinary system, which can help medical students and residents solidify their understanding of anatomical relationships within the pelvis.

The "Y"-shaped Denonvilliers' fascia and its adjacent relationship with the urogenital fascia based on a male cadaveric anatomical study

BACKGROUND

Controversies regarding the anatomical structure of Denonvilliers' fascia and its relationship with surrounding fasciae have sparked a heated discussion, especially concerning whether Denonvilliers' fascia is multilayered. This study aimed to expound on the anatomical structure of Denonvilliers' fascia and its correlation with the peritoneum from the sagittal view and clarify the complex fascial relationship.

METHODS

Our study was performed on 20 adult male pelvic specimens fixed in formalin, including 2 entire pelvic specimens and 18 semipelvic specimens. The local adjacent organs and fasciae were dissected, and Denonvilliers' fascia was observed and removed for histological examination.

RESULTS

Denonvilliers' fascia was typically single-layered and tough. On the sagittal plane, the peritoneum constituting the peritoneal reflection and Denonvilliers' fascia formed a "Y" shape. Denonvilliers' fascia originated from the peritoneal reflection, extended along the ventral side of the seminal vesicles and prostate, continuing caudally; its bilateral sides closely connected to the urogenital fascia (UGF) of the pelvic wall. In addition, histology preliminarily indicated that the basal cell layers of the peritoneum and Denonvilliers' fascia were continuous and formed a "Y" shape. Furthermore, the basal cells of the two peritonea extended to Denonvilliers' fascia, creating a fused double-layered structure. Some tiny blood vessels or a network of such vessels extended from the peritoneum to Denonvilliers' fascia.

CONCLUSION

Denonvilliers' fascia, the extension of the peritoneum in the pelvic floor, appears as a single-layered "Y"-shape on the sagittal plane. Our study provides new support for the peritoneal fusion theory. Understanding the anatomical characteristics of Denonvilliers' fascia and its relationship with the UGF is of guiding significance for inexperienced colorectal surgeons to conduct rectal cancer surgery.

Robot-assisted anorectal pull-through for anorectal malformations with rectourethral and rectovesical fistula: feasibility and short-term outcome

BACKGROUND

Multiple structures in the anorectal area are closely related to defecation, voiding and sexual function. Although laparoscopic-assisted anorectal pull-through is widely accepted as a minimally invasive surgical technique, controversy still exists for ARMs with rectourethral fistulas. Intraoperative injuries more or less involve the perirectal sphincters and neurovascular tissue.

METHODS

Seventeen selected infants with ARMs underwent robot-assisted anorectal pull-through (RAARP) between October 2016 and January 2018. The application of nerve- and sphincter-sparing technique in RAARP was detailed. The feasibility and early outcomes were evaluated.

RESULTS

All procedures were completed without conversion. The robotic system facilitated clear dissections between different anatomical layers. Under direct vision, the fistula was easier to repair, and the rectal pouch was precisely placed in the center of the striated muscle complex. During the follow-up of 11.6 months, 13 patients resumed normal defecation. The other four children experienced mild constipation or fecal incontinence. Their continence and defecation functions showed favorable evolution.

CONCLUSION

RAARP is a safe and effective alternative for the treatment of ARMs, which provides an advantage in further minimizing the injury to perirectal nerves and sphincters.

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.

The 'multilayer' theory of Denonvilliers' fascia: anatomical dissection of cadavers with the aim to improve neurovascular bundle preservation during rectal mobilization

AIM

Denonvilliers' fascia is thought to be a multilayered fascial structure, based on its embryological development with the neurovascular bundle embedded within it. Recently, this theory had been proven histologically and by confocal microscopy in many published articles. However, the literature does not report on how surgeons can identify these structures. We aimed to determine the optimal surgical approach for preserving these critical structures.

METHOD

Eighteen cadavers (13 male/five female) were included and treated according to the ethical considerations stated in the donation consent of our institution. Dissection was performed with the assistance of binocular loupes for better anatomical detail. The compositions of the prerectal fascia and the neurovascular bundle were observed and recorded at different levels of dissection using a high-definition camera.

RESULTS

The theoretical multilayered fascia was found in male specimens as three fascial layers originating from the perineal body, seminal vesicles and posterior bladder neck. The first layer merged posterolaterally and fused with the rectosacral fascia (Waldeyer's fascia). The neurovascular bundle in male specimens was observed piercing the second and third layers, while the first layer acted as a protective cover. Dissection of female specimens demonstrated only one layer in the prerectal space.

CONCLUSION

Intiating anterior rectal mobilization by incising the peritoneum posterior to its reflection seems to be anatomically correct to preserve DVF. However, its applicability may be difficult in a narrow chanllenging pelvis. The lateral rectal ligaments and Waldeyer's fascia should be dissected from their attachments to the proper fascia of the rectum.

Prediction of urinary retention after surgery for rectal cancer using voiding efficiency in the 24 h following Foley catheter removal

PURPOSE

Postoperative urinary retention is a common adverse effect after rectal surgery. Current methods for assessing postoperative urinary retention (residual urine volume) are inaccurate and unable to predict long-term retention. Voiding efficiency is an effective indicator of postoperative urinary retention in urological and gynaecological fields, but not in colorectal surgery. We aimed to determine whether voiding efficiency in the initial 24 h after urinary catheter removal was more effective in predicting the incidence of postoperative urinary retention than residual urine volume.

METHODS

In this retrospective, observational study using prospectively collected data from patients who visited the colorectal department of a single institution, 549 patients who underwent rectal cancer surgery between April 2012 and May 2016 were initially enrolled, of which 46 were excluded and 503 finally included.

RESULTS

The incidence of postoperative urinary retention was 18.5% (93/503). Multivariable logistic regression analyses revealed that the association of postoperative urinary retention with voiding efficiency < 50% was stronger than that with residual urine volume > 100 mL (odds ratio, 38.30 (residual urine volume) and 138.0 (voiding efficiency)). Voiding efficiency was significantly lower in patients with long-term than in those with short-term postoperative urinary retention (adjusted p value = 0.02), whereas residual urine volume was not different between the two groups. Multivariable logistic regression analysis for long-term postoperative urinary retention showed the strongest association with voiding efficiency < 20% (odds ratio, 25.70).

CONCLUSIONS

Voiding efficiency is a more effective predictor of postoperative urinary retention than residual urine volume in rectal cancer patients.

Reconsideration of the Anterior Surgical Plane of Total Mesorectal Excision for Rectal Cancer

INTRODUCTION

Previous studies on total mesorectal excision suggested dissection anterior to Denonvilliers' fascia, which might lead to intraoperative pelvic autonomic nerves injury and a high incidence of urogenital dysfunction.

TECHNIQUE

We dissected 4 cases of cadavers, mainly focusing on anatomy of Denonvilliers' fascia, to study the relationship between Denonvilliers' fascia and rectum. In practice, instead of dissection 1 cm above peritoneal reflection, dissection of the peritoneum was performed at the lowest level of peritoneal reflection during laparoscopic resection for mid-low rectal cancer.

RESULTS

The cadaveric study revealed that there were loose tissues between Denonvilliers' fascia and rectal specimen, thus a surgical plane posterior to Denonvilliers' fascia did exist. During laparoscopic resection for mid-low rectal cancer, some loose reticulate structures between Denonvilliers' fascia and proper fascia of rectum would present after dissection of peritoneum at the lowest level of peritoneal reflection. Then dissection within the surgical plane posterior to Denonvilliers' fascia became easy and feasible. In this plane, both the pelvic nerves and postoperative urogenital function could be well protected by Denonvilliers' fascia.

CONCLUSIONS

The anterior surgical plane for total mesorectal excision should be reconsidered, and dissection posterior to Denonvilliers' fascia is feasible and practicable for patients without risk of positive anterior circumferential resection margin.

Preservation of Denonvilliers' fascia for nerve-sparing laparoscopic total mesorectal excision: A neuro-histological study

Urogenital complications due to pelvic autonomic nerve damage frequently occur following rectal surgery. We investigated whether total mesorectal excision (TME) with preservation of the Denonvilliers' fascia (DVF) can effectively prevent the removal of pelvic autonomic nerves through microscopy. Twenty consecutive male patients with mid-low rectal cancer who received TME with preservation or resection of the Denonvilliers' fascia (P and R groups, respectively) were included. Serial transverse sections from surgical specimens were studied histologically. Nerve fibers at the surfaces of the mesorectum were counted. Clinical correlation between the amount of nerve fibers removed and post-operative sexual function was analyzed. Nerve fibers closely localized to the DVF in the R group displaying rich erectile activity (positive anti-nNOS immunostaining). At the anterior surface of the mesorectum, the mean numbers of nNOS-positive nerve fibers per specimen in the P group were significantly lower than the R group (3.0 ± 1.8 vs. 5.0 ± 2.3, P < 0.05). Compared to the R group, patients in the P group had higher IIEF scores and better erectile function at 3 and 6 months post-operatively. The DVF is a key risk zone for pelvic denervation during laparoscopic TME. Preservation of the DVF can prevent the removal of autonomic nerves and protect post-operative erectile function. Clin. Anat. 32:439-445, 2019. © 2019 Wiley Periodicals, Inc.

Ponderings on low rectal surgery

Colorectal cancer is one of the most common malignant tumors. As the development of modern medicine and the wide application of early cancer screening, rectal cancer has been found and treated timely nowadays. At present, sphincter-preserving surgery for low rectal cancer is getting more and more popular. Low rectal anastomotic fistula and pelvic autonomic nerve injuries are common complications. Improving the oncological clearance and reducing the complications have been the goals of surgeons. This article discusses several problems in low rectal surgery: (1) the selection of the cut-off location of the inferior mesenteric artery; (2) the protection of pelvic autonomic nerve plexus; (3) the anatomy of Denonvilliers' fascia; (4) the surgical strategy for preventive stoma; and (5) the improvement of drainage in pelvic floor.

Erratum: Medicine, Volume 95, Issue 24: Erratum

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