Posterior urethral reconstruction poses a challenge due to the need for visualization and repair in deep and narrow spaces, with close proximity to the external urethral sphincter. Posterior urethral stenoses commonly result from iatrogenic injury such as previous bladder outlet procedures or due to treatment effect of prostate cancer. Furthermore, patients often have significant compromise of their quality of life requiring regular dilations, intermittent catheterization, or suprapubic cystostomy.

Traditional treatment methods, including transabdominal and perineal approaches, are challenging and can lead to urinary incontinence, and frequently require pubic osteotomy. With the surgical robot, many of these difficulties can be circumvented due to dexterity and visualization in confined spaces. The advantages the robot offers are multifold: 3 double-jointed arms via minimally invasive trocars, enhanced 3D visualization, and adjuvant technology to assist with dissection and assessment of tissue viability. With the single-port robot, surgeons decrease the working space required for robot utilization, reduce operative times, as well as minimize the disruption of blood supply to the already scarred and diseased tissue. If perineal dissection is needed due to inability to reach the distal extent of the disease, the single-port robot can also be floating docked for deep perineal dissection (Figure 1). Multiple studies have shown improved and durable rates of success with lower rates of incontinence compared to open reconstruction.^1,2 Furthermore, surgeons have access to adjuvant technology to assist with tissue identification and assessment.

Figure 1. A, Perineal view. Float-docking with the single-port robot can be utilized to suture transperineally. B, Robotic view. The buccal graft (green arrow) is secured to the graft distally from the perineum using float-docking.

Key Adjuvant Technology With the Surgical Robot

Near-infrared fluorescent imaging helps to identify urinary tract structures through transillumination of the cystoscope. This can be particularly useful with urethral identification in patients with significant scar from previous surgery or urinoma. In case of a long-segment stricture, both antegrade and retrograde cystourethroscopy can be used to guide dissection of healthy proximal and distal urethra, respectively. Figure 2 shows near-infrared fluorescent imaging use for identification of the distal extent of the stenosis.³

Figure 2. Near-infrared fluorescent imaging combined with cystoscopy can help surgeons safely identify the urethral lumen.

Indocyanine green is another useful tool. This is commonly used for ureteral identification via injection into the ureter (off label). For lower urinary tract reconstruction, indocyanine green may be given intravenously for assessment for tissue vascularity. This technique is useful to assess the health of the urothelium prior to anastomosis or health of the graft bed if a mucosal graft will be used for urethroplasty.

Hydrodissection during dissection can also be used to help separate tissue planes and avoid injury to adjacent structures, such as the rectum. Laparoscopic delivery of a small-gauge needle with bedside assistance for saline injection can greatly assist safe dissection of scarred planes, as seen in Figure 3.³

Figure 3. Hydrodissection can assist in safe dissection in scarred planes. Here, the vesicourethral anastomotic stenosis is hydrodissected to safely bring the urethra away from the rectum posteriorly.

Preoperative Considerations

Characterization of the stenosis is critical in identifying the best procedure. Is the urethra obliterated or narrowed? What is the gap that must be traversed for reconstruction? Does the prostate remain in situ? Is there necrosis or dystrophic calcification? What was the patient’s continence prior to development of stenosis? Is there concomitant disease in the anterior urethra?

Some of these questions may be answered preoperatively with fluoroscopic studies or exam under anesthesia. Though preoperative diagnostics can provide insights, surgeons must be prepared for complexities encountered during reconstruction. We outline a simplified algorithm for management of posterior urethral stenosis in Figure 4.

Figure 4. Simplified algorithm for management of posterior urethral stenosis.

Techniques of Posterior Urethroplasty With the Surgical Robot

The techniques used to treat anterior urethral strictures can be applied to the posterior urethra based on the principles of robust blood flow for anastomosis or graft bed and a tension-free watertight closure. Transabdominal posterior urethral reconstruction lends more flexibility as the bladder is well perfused and its mucosa can be used for augmentation. Additionally, other bladder pathologies can be treated simultaneously. If the patient has a concomitant bladder diverticulum, this can be addressed through the same incision. Additionally, the mucosa of the bladder diverticulum can be utilized for urethroplasty if required.

An anastomotic urethroplasty can be performed if safe circumferential dissection can be achieved. This technique is required in instances of urethral obliteration and urethral or prostatic necrosis. In cases of necrosis or dystrophic calcification, we resect the diseased urethral segment, close the bladder neck, and perform a new anastomosis via a new, anterior cystotomy, as shown in Figure 5.^4,5

Figure 5. Bladder flap for new vesicourethral anastomosis (VUA) in cases of prostatic or urethral necrosis with a large remaining defect. A, The bladder neck is closed in 2 layers. B, A new cystotomy is made for the new anastomosis. C and D, The new anastomosis is secured to the urethral stump.

In cases with a patent lumen without necrosis, the anterior bladder can be used as an advancement flap. An inverted Y-shape is incised across the stenosis with the wings of the Y forming the 2 sides of the bladder flap. This V-shaped bladder flap is then advanced tension-free to the distal extent of the urethrotomy, as seen in Figure 6.

Figure 6. YV plasty for posterior urethral reconstruction can be useful for short stenoses without an obliterated lumen. A, After an anterior urethrotomy is made (Y), a V-shaped bladder flap is created. B, Advancement of the apex of the bladder flap into the distal extent of the urethrotomy.

In cases where YV plasty is not feasible, or if there is concomitant anterior stricture, buccal mucosa graft may be required for augmentation. This will often require concomitant perineal dissection, and securing the graft may be challenging. The robot can also be used for perineal dissection and urethroplasty, as seen in Figure 1.

The integration of robotic surgery in the management of posterior urethral stenosis marks a paradigm shift in urologic surgery by expanding the range of viable surgical techniques. Furthermore, the use of adjunctive technology can help with safe dissection in challenging and tightly confined spaces.