Ureteral reimplantation, bladder diverticulectomy, prostatic utricular resection, bladder augmentation, continent catheterizable channel

Introduction

Ureteral reimplantation remains the gold standard for correction of vesicoureteral reflux (VUR) refractory to nonoperative or endoscopic management. In the United States, traditional open reimplantation has progressively been supplanted by minimally invasive approaches. ^, Since the description of robot-assisted laparoscopic ureteral reimplantation (RALUR) in 2004, “minimally invasive” has increasingly become synonymous with robot-assisted laparoscopy, as the articulating wrists of the robotic surgical system facilitate easier suturing and atraumatic manipulation of the ureter. Compared to the open approach, RALUR offers similar outcomes and complication rates ^{, ,} while offering decreased length of hospital stay, less pain, and lower narcotic requirements. Higher capital and operating room costs may be offset by savings from shorter postoperative stays and faster operative times as surgeons continue to gain aptitude and comfort with RALUR. While the vast majority of pediatric RALUR is performed for VUR, it is increasingly being applied with good outcomes for anomalies of the ureterovesical junction (UVJ) such as primary obstructive megaureter.

Indications and contraindications

Treatment paradigms for VUR have evolved in light of the finding that, in the absence of intervention, the majority of cases will spontaneously resolve ^, with higher-grade and bilateral cases and those discovered at an older age less likely to do so. The underlying goal of treatment is to prevent irreversible renal scarring from ascending urinary tract infections (UTI). Open or minimally invasive ureteral reimplantation creates a one-way antirefluxing intravesical tunnel and is usually reserved for patients who have failed conservative management with continuous antibiotic prophylaxis (CAP) or endoscopic injection of bulking agents. ^, Failure can be defined as the presence of breakthrough UTIs despite CAP, noncompliance with CAP, nonresolving unilateral grade IV/V reflux, bilateral grade III reflux, high-grade reflux into a solitary or transplanted kidney, or progressively worsening renal function/scarring. Parent preference for surgery over CAP also constitutes an indication for intervention.

Society guidelines do not define absolute contraindications for RALUR in children over 1 year of age; however, relative contraindications include young age (1 to 5 years), limited life expectancy, significant cardiopulmonary comorbidities, highly complex anatomy, or congenital anomalies, such as concurrent ureterocele, prior abdominal surgeries with a high likelihood of intraabdominal adhesions and reflux in the setting of an atrophic, or minimally functioning kidney.

Preoperative assessment

The preoperative history should note age and reflux grade at initial diagnosis of VUR and initiation of CAP, number and severity of prior culture-confirmed UTI, growth and development parameters, and past medical/surgical history. Concurrent bowel/bladder dysfunction should be diagnosed and treated prior to surgery. Laboratory evaluation should establish a baseline estimated glomerular filtration rate (eGFR) as well as any temporal trends in renal function.

Recent voiding cystourethrography (VCUG) or contrast-enhanced voiding urosonography (CE-VUS) studies should be reviewed to define grade and laterality of VUR, the course and caliber of the ureters, and any findings suggestive of concurrent UPJ obstruction such as kinking or abrupt cutoff of a dilated ureter at the level of the UPJ. Renal/bladder ultrasound (RBUS), CT, or MRI imaging can be used to assess renal length, the appearance of the renal parenchyma, the degree of hydroureteronephrosis, and the presence of any anatomic abnormalities. A DMSA (technetium-99 m-labeled dimercaptosuccinic acid) scan can quantify renal function and define areas of renal cortical scarring, the presence and progression of which may support more aggressive management of VUR.

Operating room and port setup

See the box that follows for a list of equipment and Fig. 62.1 for suggested operating room setup.

Patient preparation and positioning

We do not routinely administer a bowel prep before surgery. The day of surgery, perioperative IV antibiotics are given and general endotracheal plus regional anesthesia with a caudal block is administered. The patient is positioned either in the lithotomy position if cystoscopy is to be performed at the outset of the case or supine if the procedure is performed without placement of a ureteral stent. After cystoscopy, the patient is repositioned supine on a bean bag positioner covered by a gel pad. Alternatively, older patients may be put in the low lithotomy position to allow docking of the robot between the legs; however, we have not found this necessary and routinely use the supine position for children of all ages. All pressure points are padded, the bean bag is placed to suction, and the patient is secured to the table with surgical tape to prevent movement with Trendelenburg positioning. The stability of this setup can be tested with table movement prior to sterile preparation and draping of the patient’s abdomen and genitalia. Once the patient is prepped and sterilely draped, an indwelling urinary catheter is placed on the sterile field to facilitate bladder filling and emptying during dissection. Urine for culture is collected from the catheter after placement.

Procedure steps

Access, pneumoperitoneum, and port placement

After repositioning, sterile prep and draping as above, the initial incision is made at the base of the umbilicus at the midline down to the fascia. Stay sutures are placed at either side of the fascia before opening it with scissors or cautery. The peritoneum is identified and opened sharply. The first 8-mm Xi robotic port is placed under direct vision into the peritoneum and is used to insufflate the abdomen at a pressure of 8 mmHg. The camera is placed through this 8-mm umbilical port, and the intraabdominal viscera are inspected for evidence of injury from trocar placement. Two additional 8-mm robotic ports are then placed under laparoscopic vision, at the latitude of or slightly inferior to the umbilicus, on either side at the midclavicular line ( Fig. 62.2 ). An assistant port is not usually necessary. The patient is placed in Trendelenburg position to retract the bowel out of the pelvis, and the robot is docked. The position of the robot relative to the patient may vary based on OR configuration; it can be positioned either left or right of the table near the patient’s hip. The bipolar Maryland forceps and monopolar dissecting scissors are inserted for dissection.

Mobilization of the ureter

The peritoneum is initially incised on the posterior aspect of the bladder to reveal the vas deferens (in male patients) and distal ureter ( Fig. 62.3 A). The vas deferens lies draped over the ureter and must, therefore, be gently swept off the ureter and posterior wall of the bladder. The ureter is manipulated either via lifting gently from below or by grasping the periureteral connective tissue. Great care is taken to avoid grasping the wall of the ureter itself as this can potentially result in ischemia and stricture formation or urine leak. The plane around the ureter is defined and the ureter is mobilized proximally toward the iliac vessels and distally toward the UVJ until sufficient length is achieved for a tension-free reimplantation. The bladder is partially filled with sterile saline via the urethral catheter and its posterior surface is examined in relation to the ureter to plot a trajectory for the future detrusor tunnel that will enable reimplantation without kinking or undue angulation. This can be marked by superficially scoring the bladder using monopolar electrocautery (see Fig. 62.3 B). Classically, the length of the tunnel should be five times the diameter of the ureter.

Ureteroplasty/tapering

If reimplantation is being performed for a primary obstructed megaureter ( Fig. 62.4 A) or for high-grade reflux with a dilated, tortuous ureter, ureteral tapering may be required to achieve a nonrefluxing repair. Taking care not to damage the ureteral stent if one was placed, the ureter is transected with the monopolar scissors just proximal to the UVJ or obstructed segment. Transection should be performed “cold” without the use of electrocautery. The chosen point of transection should maximize ureteral length while allowing for excision of any visibly stenotic or atretic segments. The distal ureteral remnant can be ligated with a 4-0 Vicryl suture or circumferentially excised. The remaining proximal ureter is examined to find an area of redundant tissue without large periureteral vessels. The redundant tissue is excised longitudinally, removing length roughly equal to the length of the detrusor tunnel (see Fig. 62.4 B). A running 5-0 Monocryl suture is used to approximate the ureteral wall around the stent, leaving enough circumference to avoid excessive narrowing (see Fig. 62.4 C). Care should also be taken to direct the ureteral suture line away from the bladder mucosa to prevent erosion of the sutures or ureteral fistula to the bladder.

Ureteral advancement and detrusorrhaphy

If the ureter was not transected, a 4-0 Vicryl horizontal mattress suture was used to advance the ureter distally along the detrusor tunnel toward the trigone. This most distal stitch incorporates detrusor, then ureteral adventitia ( Fig. 62.5 A), and detrusor again (see Fig. 62.5 B). Reapproximation of the tunnel can then proceed from distal to proximal. Alternately, after the distal advancement stitch is placed, the most proximal stitch can be placed next, slinging the ureter into the tunnel. Detrusor flaps are then closed over the ureter with interrupted sutures (see Fig. 62.5 C–E). Small bites of ureteral adventitia can be incorporated periodically to prevent migration of the ureter out of the tunnel. After inspecting the hiatus to ensure the ureter is not constricted by the closure, the hitch stitch is taken down, the bladder partially filled, and the course of the ureter examined to ensure there is no kinking or J-hooking (see Fig. 62.5 E).

If the tapered ureter was transected, reanastomosis to the bladder can be performed either at the site of the excised segment of the distal ureter or through a new bladder mucosectomy. An initial horizontal mattress stitch advancing the ureter distally and incorporating full-thickness bladder into the ureter is placed and tied down. The distal curl of the ureteral stent is placed in the bladder through the mucosectomy, and interrupted 5-0 Vicryl sutures are placed to approximate the ureter to the bladder mucosa (see Fig. 62.4 D). The detrusorrhaphy is then performed, closing detrusor flaps over the tailored ureter as above with interrupted 4-0 Vicryl sutures.

Postoperative care

Any remaining fluid deficit not replaced intraoperatively is returned via IV fluid boluses in the postanesthesia care unit (PACU) and on the inpatient floor. Ketorolac and acetaminophen are given on a scheduled basis unless contraindicated. Additional analgesia requirements are uncommon. On postoperative day 1 (POD 1), the patient’s urinary catheter is removed, and he or she is advanced to a general diet and discharged if voiding and ambulating without issue. Antimicrobial prophylaxis is usually continued for 3 months. If a ureteral stent is placed, it is removed in 4 to 6 weeks. A RBUS is performed prior to stent removal and repeated 4 to 6 weeks later. Reassessment for reflux with a repeat VCUG or CE-VUS is discussed with the family, and if performed, is done 3 months postoperatively. If imaging is normal after surgical correction, monitoring consists of annual blood pressure, height/weight, and urinalysis, with further imaging not indicated in the absence of concurrent bladder dysfunction or recurrent febrile UTI.

Complications

Reported overall complication rates following RALUR vary widely between centers and range from 0% to 40%. A contemporary multicenter study of 199 reimplantations in 143 patients between 2015 and 2017 noted an overall 5.6% rate of Clavien grade III complications, with no grade 4 or 5 complications and no reoperations.

The most common complication of RALUR is urinary retention (0% to 40% of cases), which is usually transient and self-resolving. As in open extravesical ureteral reimplantation, the theorized mechanism is disruption of nerves of the pelvic plexus, which run dorsal and medial to the UVJ. ^, However, the classical view is this risk precludes bilateral extravesical reimplantation. Casale et al. described a series of 41 bilateral extravesical robotic repairs with no episodes of postoperative urinary retention, indicating that RALUR can safely be performed bilaterally. With appropriate attention to bowel and bladder dysfunction preoperatively combined with judicious use of extravesical cautery, successful bilateral extravesical ureteral reimplantation is commonly performed by some at our institution via both open and RAL approaches.

Ureteral obstruction and urine leak are less common complications (<7% of cases). ^, Urinary leakage can often be managed with the placement of an indwelling ureteral stent or percutaneous nephrostomy tube. Transient ureteral obstruction is usually caused by ureteral edema immediately following a stentless repair. If this is the case, it can often be managed conservatively in the absence of overt signs of infection. Persistent obstruction due to suture placement or stricture formation is uncommon.

Summary

Robotic ureteral reimplantation offers comparable outcomes and complication rates as compared to the gold standard of open repair for VUR. Decreased pain requirements, shorter inpatient length of stay and more cosmetic incisions have led to progressively more widespread adoption. The technique described here is applicable to both straightforward ureteral reimplantation and more challenging dilated ureters requiring tapering. As treatment paradigms for VUR continue to evolve and robotic surgery becomes increasingly commonplace, RALUR will likely be a key element of the pediatric urologist’s skillset.

Introduction

Pediatric bladder diverticula are a relatively rare entity, with an incidence estimated at 0.7% to 1.7%. ^, There is an approximately 90% male predominance. Although some pediatric diverticula are associated with chronic bladder outlet or neurogenic dysfunction as is seen classically in adults, the majority are theorized to be caused by congenital weakness or hypoplasia of the detrusor. This allows for outpouching of the bladder mucosa through the muscular wall of the bladder, usually in the vicinity of the UVJ. ^, As such, congenital bladder diverticula (CBD) can involve both mucosal and muscular layers and are frequently associated with VUR. ^, A further distinction is made between “paraurethral” congenital diverticula, in which the UO opens within the diverticulum, and “periureteral” diverticula in which the ureteral and diverticular orifices are distinct with separate investing fascial layers. Although the majority of cases are sporadic, associations have been noted with congenital syndromes affecting connective tissues such as Occipital Horn (formerly Ehlers–Danlos type IX), Williams-Beuren, and Menkes syndromes.

Traditionally, open excision via an intravesical or extravesical approach has been the gold standard for treatment of symptomatic CBD. The advent of minimally invasive pure laparoscopic approaches offered a less morbid alternative, although a more technically challenging one given the need for intracorporeal suturing of the diverticulectomy defect. In 2007, Myer and Wagner presented the first series of robot-assisted laparoscopic (RAL) bladder diverticulectomies in five adults, followed by our group’s initial description of pediatric robot-assisted laparoscopic bladder diverticulectomy (RALBD) in 2009. As in RAL ureteral reimplantation, robotic systems offer a minimally invasive approach with stable, magnified 3-D visibility and articular motion, facilitating gentle dissection, suturing, and knot tying. While no large studies have compared RAL, laparoscopic, and open approaches in children, small series have demonstrated good results with pediatric RALBD.

Indications and contraindications

Although there are no strict indications for surgery, repair is typically performed for very large or symptomatic bladder diverticula. Most pediatric patients with CBD are asymptomatic; however, those who present most frequently exhibit symptoms related to urinary stasis within the acontractile diverticulum. The most common presentation is UTI, although gross hematuria, stones and bladder outlet obstruction/acute urinary retention are also seen. In the setting of concurrent VUR, patients may present with pyelonephritis. Rarer presentations associated with large diverticula include ureteral obstruction, vascular compression, prolapse, and rupture.

There are similarly no strict operative contraindications related to the diverticulum itself. Rather the decision to operate must account for patient age, symptom severity, the size of the diverticulum, its proximity to surrounding pelvic structures, the presence and grade of concurrent VUR, medical comorbidities, congenital syndromes predisposing to recurrence, and prior abdominal surgeries.