Anatomical approach for surgery of the male posterior urethra

Dissection of the Male Urethra Demonstrating Its Topographical Specificity

The urethra is a long muscular tubular organ that changes its internal configuration as it traverses different regions. Therefore, the pathology of each region is distinctive, and regional characteristics may influence exploration and treatment. We set out to perform detailed dissections of the male urethra and illustrate the regional specificity for each urethral segment. Therefore, we dissected the vesical cervix, showing both the normal appearance and the appearance of prostatic middle lobe adenoma. We dissected the prostatic urethra, showing the seminal colliculus, ejaculatory ducts, and prostatic utricle. We revealed the membranous urethra surrounded by the striated sphincter. We have shown the appearance of the spongy urethral bulb with its cul-de-sac appearance, the aspect of the urethral lacunae, the navicular fossa, and the external urethral meatus. We performed cross-sections through the prostatic urethra as well as dissection of the bulbourethral glands at the level of the urogenital diaphragm. All the information obtained through dissection is illustrated in high-quality graphic form and correlated with clinical applications, making this work valuable teaching material.

Anatomy of muscle connections in the male urethra and anorectal canal

OBJECTIVES

To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence.

METHODS

Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D.

RESULTS

The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter.

CONCLUSION

This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.

Multi-Institutional Study of Dorsal Onlay Urethroplasty of the Membranous Urethra after Endoscopic Prostate Procedures: Operative Results, Continence, Erectile Function and Patient Reported Outcomes

(1) Background: To critically evaluate dorsal onlay buccal mucosal graft urethroplasty (DOBMGU) for posterior urethral stenosis repair following transurethral resection and other endoscopic prostate procedures. (2) Methods: A retrospective multi-institutional review of patients with membranous or bulbomembranous urethral stenosis for whom treatment with DOBMGU was conducted after receipt of prostate endoscopic procedures. Baseline data, peri-operative care, post-operative care and patient-reported outcomes were analyzed. The primary outcomes were procedural failure and development of de novo stress urinary incontinence (SUI). The secondary outcomes were changes in voiding, sexual function and patient satisfaction. (3) Results: A total of 107 men with a mean age of 69 ± 9.5 years and stenosis length of 3.5 ± 1.8 cm were included. Prior endoscopic procedures among participants were 47 patients (44%) with monopolar TURP, 33 (30.8%) with bipolar TURP, 16 (15%) with Greenlight laser, 9 (8.4%) with Holmium laser enucleation and 2 (1.9%) with bladder neck incision. At a mean follow-up time of 59.3 ± 45.1 months, stenosis recurred in 10 patients (9.35%). Multivariate analysis confirmed that postoperative complications (OR 12.5; p = 0.009), history of radiation (OR 8.3; p = 0.016) and ≥2 dilatations before urethroplasty (OR 8.3; p = 0.032) were independent predictors of recurrence. Only one patient (0.9%) developed de novo SUI. Patients experienced significant improvement in PVR (128 to 60 cc; p = 0.001), Uroflow (6.2 to 16.8 cc/s; p = 0.001), SHIM (11.5 to 11.7; p = 0.028), IPSS (20 to 7.7; p < 0.001) and QoL (4.4 to 1.7; p < 0.001), and 87 cases (81.3%) reported a GRA of + 2 or better. (4) Conclusions: DOBMGU is an effective and safe option for patients with posterior urethral stenosis following TURP and other prostate endoscopic procedures. This non-transecting approach minimizes external urinary sphincter manipulation, thus limiting postoperative risk of SUI or erectile dysfunction.

Preoperative exercise interventions to optimize continence outcomes following radical prostatectomy

Urinary incontinence is a common and predictable consequence among men with localized prostate cancer who have undergone radical prostatectomy. Despite advances in the surgical technique, urinary continence recovery time remains variable. A range of surgical and patient-related risk factors contributing to urinary incontinence after radical prostatectomy have been described, including age, BMI, membranous urethral length and urethral sphincter insufficiency. Physical activity interventions incorporating aerobic exercise, resistance training and pelvic floor muscle training programmes can positively influence the return to continence in men after radical prostatectomy. Traditional approaches to improving urinary continence after radical prostatectomy have typically focused on interventions delivered during the postoperative period (rehabilitation). However, the limited efficacy of these postoperative approaches has led to a shift from the traditional reactive model of care to more comprehensive interventions incorporating exercise-based programmes that begin in the preoperative period (prehabilitation) and continue after surgery. Comprehensive prehabilitation interventions include appropriately prescribed aerobic exercise, resistance training and specific pelvic floor muscle instruction and exercise training programmes. Transperineal ultrasonography is a non-invasive and validated method for the visualization of the action of the pelvic floor musculature, providing real-time visual biofeedback to the patient during specific pelvic floor muscle instruction and training. Importantly, the waiting time before surgery can be used for the delivery of comprehensive prehabilitation exercise-based interventions to increase patient preparedness in the lead-up to surgery and optimize continence and health-related quality-of-life outcomes following radical prostatectomy.

Intrasphincteric anastomotic urethroplasty allows preservation of continence in men with bulbomembranous urethral strictures following benign prostatic hyperplasia surgery

PURPOSE

Injury to the external sphincter during urethroplasty at or near the membranous urethra can result in incontinence in men whose internal sphincter mechanism has been compromised by previous benign prostatic hyperplasia (BPH) surgery. We present outcomes of a novel reconstructive procedure, incorporating a recent anatomic discovery revealing a connective tissue sheath between the external sphincter and membranous urethra, which provides a surgical plane allowing for intrasphincteric bulbo-prostatic urethroplasty (ISBPA) with continence preservation.

METHODS

Stricture at or near the membranous urethra after transurethral resection (TURP) or open simple prostatectomy (OSP) was reconstructed with ISBPA. The bulbomembranous junction is approached dorsally with a bulbar artery sparing approach and the external sphincter muscle is carefully reflected, exposing the wall of the membranous urethra. Gentle blunt dissection along this connective tissue plane allows separating the muscle away up to the prostatic apex, where healthy urethra is found for anastomosis.

RESULTS

From January 2010 to August 2019, 40 men (18 after TURP and 22 after OSP) underwent ISBPA at a single institution. Mean age was 67 years (54-82). Mean stricture length was 2.6 cm (1-6) with obliterative stricture identified in 10 (25%). At a mean follow-up of 53 months (10-122), 36 men (90%) are free of stricture recurrence and 34 (85%) were completely dry or using one security pad.

CONCLUSION

This novel intrasphincteric urethroplasty technique for stricture following BPH surgery is feasible and safe, allowing successful reconstruction with continence preservation in most patients. A larger series and reproduction in other centers is needed.

Appropriate preoperative membranous urethral length predicts recovery of urinary continence after robot-assisted laparoscopic prostatectomy

PURPOSE

We investigated that preoperative membranous urethral length (MUL) would be associated with the recovery of urinary continence after robot-assisted laparoscopic prostatectomy (RALP).

PATIENTS AND METHODS

We studied 204 patients who underwent RALP between May 2013 and March 2016. All patients underwent pelvic magnetic resonance imaging (MRI) preoperatively to measure MUL. Urinary continence was defined as the use of one pad or less (safety pad). The 204 patients were divided into two groups: continence group, those who achieved recovery of continence at 3, 6, and 12 months after RALP, and incontinence group, those who did not. We retrospectively analyzed the patients in terms of preoperative clinical factors including age, body mass index (BMI), estimated prostate volume, neurovascular bundle salvage, history of preoperative hormonal therapy, and MUL.

RESULTS

The safety pad use rate was 69.6%, 86.9%, and 91.1% at 3, 6, and 12 months, respectively. On univariate and multivariate analyses, MUL were significant factors in every term of recovery of urinary continence in both groups. According to the receiver operating characteristic (ROC) curve analysis, the preoperative MUL that could best predict early recovery of urinary continence at 3 months after RALP was 12 mm.

CONCLUSIONS

We suggest that preoperative MUL > 12 mm would be a predictor of early recovery of urinary continence after RALP.

Anatomy and techniques in posterior urethroplasty

Given its complex anatomy, injury to the posterior urethra may result in a number of reconstructive challenges. With the appropriate operative planning and experience, surgical repair can be very successful. This review discusses the applicable techniques for the perineal approach to posterior urethral stenosis, including bulbomembranous anastomosis for pelvic fracture urethral injury and repair of vesicourethral anastomotic stenosis (VUAS) following prostate surgery. The advanced techniques reviewed include an adaptation allowing a bulbar artery sparing approach to posterior urethroplasty and an intrasphincteric urethroplasty procedure which may allow continence preservation in patients with membranous urethral stenosis.

Reconstruction of Membranous Urethral Strictures

PURPOSE OF REVIEW

Due to the proximity of the rhabdosphincter and cavernous nerves to the membranous urethra, reconstruction of membranous urethral stricture implies a risk of urinary incontinence and erectile dysfunction. To avoid these complications, endoscopic management of membranous urethral strictures is traditionally favored, and bulboprostatic anastomosis is reserved as the main classical approach for open reconstruction of recalcitrant membranous urethral stricture. The preference for the anastomotic urethroplasty among reconstructive urologists is likely influenced by the familiarity and experience with trauma-related injuries. We review the literature focusing on the anatomy of membranous urethra and on the evolution of treatments for membranous urethral strictures.

RECENT FINDINGS

Non-traumatic strictures affecting bulbomembranous urethra are typically sequelae of instrumentation, transurethral resection of the prostate, prostate cancer treatment, and pelvic irradiation. Being a different entity from trauma-related injuries where urethra is not in continuity, a new understanding of membranous urethral anatomy is necessary for the development of novel reconstruction techniques. Although efficacious and durable to achieve urethral patency, classical bulboprostatic anastomosis carries a risk of de-novo incontinence and impotence. Newer and relatively less invasive reconstructive alternatives include bulbar vessel-sparing intra-sphincteric bulboprostatic anastomosis and buccal mucosa graft augmented membranous urethroplasty techniques. The accumulated experience with these techniques is relatively scarce, but several published series present promising results. These approaches are especially indicated in patients with previous transurethral resection of the prostate in which sparing of rhabdosphincter and the cavernous nerves is important in attempt to preserve continence and potency. Additionally, introduction of buccal mucosa onlay grafts could be especially beneficial in radiation-induced strictures to avoid transection of the sphincter in continent patients, and to preserve the blood supply to the urethra for incontinent patients who will require artificial urinary sphincter placement. The evidence regarding erectile functional outcomes is less solid and this item should be furtherly investigated.

Preoperative Membranous Urethral Length Measurement and Continence Recovery Following Radical Prostatectomy: A Systematic Review and Meta-analysis

CONTEXT

Membranous urethral length (MUL) measured prior to radical prostatectomy (RP) has been identified as a factor that is associated with the recovery of continence following surgery.

OBJECTIVE

To undertake a systematic review and meta-analysis of all studies reporting the effect of MUL on the recovery of continence following RP.

EVIDENCE ACQUISITION

A comprehensive search of PubMed, EMBASE, and Scopus databases up to September 2015 was performed. Thirteen studies comprising one randomized controlled trial and 12 cohort studies were selected for inclusion.

EVIDENCE SYNTHESIS

Four studies (1738 patients) that reported hazard ratio results. Every extra millimeter (mm) of MUL was associated with a faster return to continence (hazard ratio: 1.05; 95% confidence interval [CI]: 1.02-1.08, p<0.001). Eleven studies (6993 patients) reported the OR (OR) for the return to continence at one or more postoperative time points. MUL had a significant positive effect on continence recovery at 3 mo (OR: 1.08, 95% CI: 1.03-1.14, p=0.004), 6 mo (OR: 1.12, 95% CI: 1.09-1.15, p<0.0001). and 12 mo (OR: 1.12, 95% CI: 1.03-1.22, p=0.006) following surgery. After adjusting for repeated measurements over time and studies with overlapping data, all OR data combined indicated that every extra millimeter of MUL was associated with significantly greater odds for return to continence (OR: 1.09, 95% CI: 1.05-1.15, p<0.001).

CONCLUSIONS

A greater preoperative MUL is significantly and positively associated with a return to continence in men following RP. Magnetic resonance imaging measurement of MUL is recommended prior to RP.

PATIENT SUMMARY

We examined the effect that the length of a section of the urethra (called the membranous urethra) had on the recovery of continence after radical prostatectomy surgery. Our results indicate that measuring the length of the membranous urethra via magnetic resonance imaging before surgery may be useful to predict a longer period of urinary incontinence after surgery, or to explain a delay in achieving continence after surgery.

The mechanism of continence after posterior urethroplasty

The standard of care after a pelvic fracture urethral injury is a repair via a one-stage anastomotic posterior urethroplasty using a step-wise perineal approach. The initial injury, immediate postoperative management, and surgical repair can all affect urinary continence in these patients. Proximal continence mechanisms, particularly the bladder neck, are particularly important in maintaining urinary continence in these patients. Patients with bladder neck dysfunction should be counselled about the greater risk of urinary incontinence.

[Anatomy and anatomical foundations of urethral surgery]

To achieve an optimal outcome after urethral reconstructive surgery knowledge of urethral and urogenital anatomy is mandatory. It is necessary to know the anatomical characteristics of grafts and flaps to achieve successful surgical results. An ideal graft is not yet available and an optimal surgical outcome depends on the technique of harvesting, graft handling and histological transplant characteristics. Surgical technique and experience are building a successful urethral surgery out of the challenge.

Current concepts in the management of pelvic fracture urethral distraction defects

OBJECTIVES

Pelvic fracture urethral distraction defect (PFUDD) may be associated with disabling complications, such as recurrent stricture, urinary incontinence, and erectile dysfunction. In this article we review the current concepts in the evaluation and surgical management of PFUDD, including redo urethroplasty.

MATERIALS AND METHODS

A PubMed™ search was performed using the keywords "pelvic fracture urethral distraction defect, anastomotic urethroplasty, pelvic fracture urethral stricture, pelvic fracture urethral injuries, and redo-urethroplasty." The search was limited to papers published from 1980 to March 2010 with special focus on those published in the last 15 years. The relevant articles were reviewed with regard to etiology, role of imaging, and the techniques of urethroplasty.

RESULTS

Pelvic fracture due to accidents was the most common etiology of PFUDD that usually involved the membranous urethra. Modern cross-sectional imaging, such as sonourethrography and magnetic resonance imaging help assess stricture pathology better, but their precise role in PFUDD management remains undefined. Surgical treatment with perineal anastomotic urethroplasty yields a success rate of more than 90% in most studies. The most important complication of surgical reconstruction is restenosis, occurring in less than 10% cases, most of which can be corrected by a redo anastomotic urethroplasty. The most common complication associated with this condition is erectile dysfunction. Urinary incontinence is a much rarer complication of this surgery in the present day.

CONCLUSIONS

Anastomotic urethroplasty remains the cornerstone in the management of PFUDD, even in previously failed repairs. Newer innovations are needed to address the problem of erectile dysfunction associated with this condition.