Robotic Versus Open Distal Ureteral Reconstruction and Reimplantation for Benign Stricture Disease

Abstract

Background and Purpose:

Minimally invasive techniques are currently used for numerous urologic procedures, given decreased morbidity and equivalent outcomes to open surgery. There is, however, a relative paucity of data related to robot-assisted ureteral reimplantation (RAUR) in adult patients for benign stricture disease. We sought to determine the periprocedure outcomes of open distal ureteral reimplantation vs RAUR at our institution.

Patients and Methods:

We retrospectively identified 10 consecutive mid/distal RAUR procedures performed by one surgeon since 2005. Twenty-four patients undergoing open mid/distal ureter reconstruction over the same period were identified, and 10 controls matched for age and body mass index (BMI) were used for comparison. Demographic, operative, and clinical/radiographic outcomes were compared.

Results:

Etiology of the strictures included stone disease (n=8, 40%), iatrogenic injury during previous abdominopelvic surgery (n=10, 50%), or other causes (n=2, 10%). None of the robotic procedures necessitated conversion to open surgery. No intraoperative complications occurred. Six neocystostomies, three psoas hitches, and one Boari flap were completed in an open fashion. Four neocystostomies, four psoas hitches, and two Boari flaps were performed in the RAUR group. Estimated blood loss (30.6 vs 327.5 mL, P=0.001) and length of hospital stay (2.4 vs 5.1 d, P=0.01) were significantly reduced in the robotic group. Median BMI (29.4±5.3 vs 26.5±5.2, P=0.130) and operative time in minutes (306.6 vs 270.0 min, P=0.316) were higher in the robotic group, although these were not statistically significant. None of the patients in either group had clinical or radiologic evidence of recurrent stricture disease at a median follow-up of 30 and 24 months in the open and RAUR groups, respectively. The retrospective comparative nature of this study may introduce selection bias.

Conclusions:

In experienced hands, RAUR for mid/distal benign ureteral strictures appears to be a reasonable alternative to open surgery.

Introduction

B enign distal ureteral strictures are commonly caused by iatrogenic injuries during pelvic surgery. Crush, burn, and complete transection can all occur at the time of pelvic surgery. Nonsurgical causes of strictures include urolithiasis, radiation, penetrating trauma, infection, and retroperitoneal fibrosis. Repair of these lesions may pose significant challenges based on the length and location of the stricture, as well as the quality of adjacent periureteral tissue.

Multiple approaches have been described for surgical repair of ureteral stricture, including primary anastomosis, psoas hitch, and Boari flap.^1

–5 With the continued refinement of laparoscopic instruments and surgical technique, several authors have described the laparoscopic approach for surgical repair.^2,6,7 The technical expertise needed for suture repair and dissection may have prevented widespread use of the laparoscopic approach. Robotic surgical systems have been used increasingly in urologic pelvic procedures, given purported increased dexterity of intracorporeal suturing and improved visualization.

The minimally invasive benefits and ease of operation experienced with robotic prostatectomy and upper tract surgery led us to hypothesize that such a technique could be used in repairing distal ureteral strictures. We report our experience with robot-assisted ureteral reimplantation (RAUR) for benign stricture disease of the mid to distal ureter. We compare our consecutive series of robotic ureteral reconstructions to age-matched controls undergoing open surgical repair. Our aim was to validate the safety and efficacy of the robotic approach against the current standard represented by the open approach.

Patients and Methods

We retrospectively identified 10 consecutive RAUR (nine patients) procedures and 24 open ureteral reimplant procedures performed at our institution since January 2005. Decision for an open vs minimally invasive approach to surgical treatment was based on t he surgical referral pattern to our urology department (ultimately surgeon preference) rather than specific inclusion or exclusion criteria. Indication for surgery was benign mid to distal ureteral stricture disease.

All minimally invasive procedures were performed by one experienced minimally invasive surgeon (AM) using the da Vinci Surgical System HD (Intuitive Surgical, Sunnyvale, CA). The surgeon performed ∼200 robotic procedures and 200 laparoscopic procedures before performing the first robotic ureteral procedure. Of the 24 patients undergoing open distal ureteral reconstruction over the same time period, 10 age-matched controls were selected for comparison. Perioperative outcomes were compared between the two groups. Open surgery was performed by three experienced surgeons at our institution.

All patients had cross-sectional imaging in the form of CT or MRI as part of their initial diagnostic studies. Patients were further evaluated preoperatively with retrograde pyelography to define stricture location. Antegrade nephrostography was performed concurrently when nephrostomy tubes were placed. In cases where symptomatic or complete obstruction was not noted or if the function of the kidney was in question, a mercaptoacetyl triglycine (MAG)3 renal scan with Lasix was performed. Urine cytology was obtained to rule out malignancy. Cystography was performed to determine bladder capacity and to plan the surgical approach.

Surgical technique

The technique for open ureteral reimplantation, with or without psoas hitch or Boari flap, is well described.⁸ We describe our approach for RAUR.

Patient position and access

The patient is positioned supine with legs abducted on a split leg table. Pneumoperitoneum is achieved via a Veress⁹ needle or Hasson technique and a six-trocar robotic arrangement is used. Trocar placement is similar to that of robot-assisted laparoscopic prostatectomy; however, all trocars are placed slightly more cephalad. Camera trocar is placed approximately 2 cm above the umbilicus. Two robotic trocars are placed on either side of the camera trocar approximately 8 cm from the midline. We place two assistant trocars on the left side, one most lateral 1 cm cephalad to the anterior superior iliac spine and the other between the camera trocar and the left robotic trocar. The robotic fourth arm (third functional noncamera arm) is placed most lateral on the right side, 1 cm cephalad to the anterior superior iliac spine.

Dissection of the ureter

The ureter is identified and dissected, maintaining periureteral blood supply. A vessel loop placed around the ureter aids in atraumatic ureter handling. The ureter is dissected distally to the point where it is encased in scar tissue. The ureter is transected at this point, and a portion is sent to the pathology laboratory to rule out underlying malignancy. The proximal end of the stricture is spatulated. The bladder is dropped, and the space of Retzius is entered. The contralateral obliterated ligament is divided if necessary. In cases where additional bladder mobility is necessary, the contralateral superior vesical artery is divided. Care is taken not to traumatize the contralateral ureter.

Ureteral reconstruction

An assessment is made based on ureter length and bladder capacity as to what type of distal ureter reconstruction will be necessary. In the case of an ureteroneocystostomy, an approximately 2 cm extravesical lateral incision is made on the bladder down to the mucosa. In cases where the ureteral length is insufficient to perform primary reimplantation, a psoas hitch is first performed.

The posterior wall of the bladder is sutured (seromuscular layer) onto the psoas muscle using 2-0 polypropylene sutures. Care is taken to place the tacking sutures lateral to the genitofemoral nerve. If needed, a Boari flap is created beginning about 3 cm cephalad to the bladder neck and extending up to the dome. The flap is fixated to the psoas muscle. The distal spatulated end of the ureter is anastomosed to the bladder using interrupted 3-0 and 4-0 polyglactin sutures in refluxing fashion. The flap is closed over itself in standard fashion with running polyglactin suture.¹⁰ The ureter is spatulated posteriorly for both ureteroneocystosomy and psoas hitch, and anteriorly for the Boari flap.

In all cases, a 4.8F multicoil Double-J stent is placed in the ureter by the bedside assistant through a 2-mm miniport. After completing the anastomosis, the bladder is filled with approximately 250 mL of saline, and the anastomosis is inspected for leakage and tension.

Follow-up

All patients underwent cystography 7 to 10 days postoperatively. If the patient had a nephrostomy tube, antegrade nephrostography was obtained within 14 days of surgery. We removed ureteral stents in the office ∼6 weeks after surgery. A nuclear renal scan was obtained 2 months after removal of the ureteral stent to demonstrate patency. Subsequent follow-up at 6-month intervals for 2 years included renal ultrasonography, nuclear scan, or intravenous urography, at the discretion of the ordering surgeon.

Statistics

Demographic and operative parameters were compared using Student t test, Wilcoxon rank sum, or Fisher exact test as appropriate.

Results

Nine patients (four men and five women) with a mean age of 49.3 years (range 27–63 y) underwent 10 RAUR (Table 1). Five patients had strictures related to previous stone disease and four had iatrogenic injuries incurred during previous surgeries, including laparoscopic/robot-assisted total abdominal hysterectomy (n=2), transurethral laser treatment of the prostate for benign stricture disease (bilateral ureteral injury), and Cesarean section. Three patients had percutaneous nephrostomy tubes placed preoperatively while three patients had internalized ureteral stents. Five patients had left-sided disease, three right-sided, and one bilateral. The mean American Society of Anesthesiologists (ASA) score was 1.8, and mean body mass index (BMI) was 29.4±5.3. Mean stricture length was 2.6 cm. Four neocystostomy, four psoas hitch, and two Boari flap procedures were performed in the RAUR group (Table 2).

Table 1.

Patient Procedures/Characteristics

	Open (n=10)	RAUR (n=10)	P value
Age (range)	53.7 (40–63)	49.3 (27–63)	0.589
% Male	40%	50%	0.080
ASA	2	1.8	1.000
BMI	26.5±5.2	29.4±5.3	0.130
Side of disease:
Right	6	5
Left	4	3
Bilateral	0	1
Stricture length (cm)	2.7	2.6	0.851

RAUR=robot-assisted ureteral reimplantation; ASA=American Society of Anesthesiologists; BMI=body mass index.

Table 2.

Etiology of Stricture and Procedure Performed

	Open (n=10)	RAUR (n=10)
Etiology
Iatrogenic injury	5	5
Stone disease	3	5
Infection/idiopathic	2	0
Procedure
Neocystostomy	6	4
Psoas hitch	3	4
Boari flap	1	2

RAUR = robot-assisted ureteral reimplantation.

The mean age in the open group was 51.3 years (range 33–63 y) and comprised six females and four males. Mean ASA was 2, and mean BMI was 26.5±5.2 (Table 1). Six patients had right-sided stricture, and four patients, left-sided. Strictures developed in five patients after iatrogenic injury to the ureter, three were from stone disease, one evolved from chronic infections, and one was idiopathic. Mean stricture length was 2.7 cm. Four patients had percutaneous nephrostomy tubes place preoperatively, and four had internalized ureteral stents. Six neocystostomies, three psoas hitches, and one Boari flap were completed in an open fashion. The number of open procedures remained stable over the course of our study period, with an equal distribution across the years.

None of the robot-assisted operations necessitated open conversion for completion. No intraoperative complications occurred in either group. Estimated blood loss was significantly reduced in the robotic cohort, with a mean of 30.6 mL±11.0 mL compared with 327.5 mL±695.7 mL in the open group (P=0.001). One patient in the open group needed a blood transfusion. Slightly longer median operative times (306 vs 270 min), P=0.316) in the robotic compared with open surgeries were not statistically significant.

Postoperative pain, as measured by mean intravenous morphine equivalent use, was decreased in the RAUR group (69.0 mg vs 174.1 mg), but this was not statistically significant (P=0.22). Length of stay was significantly shorter for the robot-assisted group (2.4 days vs 5.1 days, P=0.01). All patients in both groups had clinical resolution of ureteral obstructive symptoms after surgery. No patients demonstrated radiologic evidence of recurrent stricture disease (typically, MAG3 Lasix renal scan). Median follow-up was 30 months vs 24 months for the RAUR and open group, respectively (P=0.718). Follow-up data were available for all patients up to 12 months (Table 3). Most patients did not have further urologic follow-up after 24 months.

Table 3.

Outcomes

	Open (n=10)	RAUR (n=10)	P value
Operative time (min)	270.0±182.8	306.6±48.4	0.316
EBL (mL)	327.5±695.7	30.6±11.0	0.001
LOS (POD discharge)	5.1±2.6	2.4±1.2	0.010
Mean morphine equivalents used (mg)	174.7	69.0	0.222
Median follow-up (mos)	30	24	0.718

RAUR=robot-assisted ureteral reimplantation; EBL=estimated blood loss; LOS=length of stay; POD=postoperative day.

Discussion

Open ureteral reimplantation has been the standard therapy since the 1960s for benign distal ureter stricture disease that is not amenable to endoscopic repair. Ehrlich and colleagues¹¹ first reported minimally invasive ureteral reimplantation in humans in 1994 in pediatric patients. They described the technique in two pediatric patients with vesicoureteral reflux. Both patients were discharged from the hospital within 23 hours. In addition, they cited decreased pain and improved cosmesis as benefits of this approach. Reddy and Evans¹² advanced the laparoscopic technique of ureteroneocystostomy in the adult population in 1994. In this case report, a 74-year-old man needed no intravenous pain medication postoperatively and was discharged to home after 48 hours. He was disease free at 1-year follow-up. In a retrospective analysis of 10 laparoscopic to 10 open ureteral reimplantation cases, Rassweiller and associates¹³ noted significant advantages for the laparoscopic group in terms of decreased estimated blood loss (370 vs 610 mL), decreased postoperative analgesic requirement (4.9 vs 21.5 mg), and shorter hospital stays (9.2 vs 19.1 d).

In 2001, Fugita and coworkers⁷ first demonstrated the feasibility of a laparoscopically constructed Boari flap in three patients with distal ureteral obstruction. Case reports have since been described for this technique without a large single surgeon experience identified.^14,15 Most reports of laparoscopic distal ureteral reconstruction highlight the challenging nature of the procedure, particularly intracorporeal suturing of the distal ureter. While feasibility has been clearly demonstrated, significant experience with laparoscopy and excellent suturing skills are needed, which has limited its widespread use.

The adoption of robotic technology for complex urologic surgery has helped alleviate many of the perceived difficulties that are associated with traditional laparoscopy. In particular, three-dimensional visualization and six degrees of freedom at the instrument wrist have reduced the difficulty of intracorporeal suturing. Uberoi and associates¹⁶ first described the robot-assisted ureteroneocystostomy with psoas hitch combined with a distal ureterectomy for mid and distal ureteral tumors in 2007. Casale and colleagues¹⁷ published the largest series of robot-assisted extravesical reimplantation to date for 41 pediatric patients undergoing the procedure for vesicoureteral reflux.

Patil and coworkers¹⁸ published the largest series of robotic distal ureteral reconstruction for benign disease in an adult population. In this multi-institutional study, the authors described their experience with 12 patients, 10 with benign stricture disease and 2 with ureterovaginal fistulae. All of the strictures were repaired using a psoas hitch with ureteral reimplantation. At a mean follow-up of 15.5 months, none of the patients had radiologic evidence of disease using either intravenous urography or MAG3 renal scans. This group established the feasibility of a robotic approach for management of distal ureteral stricture disease. A significant limitation, however, was the fact that the study took place across 3 continents with vastly different healthcare systems. This impacted length of stay, catheter duration, and duration of Double-J stent usage based on current practices in each of the countries. Standardization was thus difficult.

To the best of our knowledge, this series represents one of the largest single institution experiences with robotic mid/distal ureteral reconstruction. We began performing robot-assisted ureteral reimplantation in 2005, having already gained significant surgical experience with laparoscopic/robotic urologic surgery. In our retrospective comparison, the perioperative outcomes and surgical success rates appear equivalent to open repair. In addition, estimated blood loss was significantly lower. Given the relatively small numbers in each group, assessment of blood transfusion rates is not possible. Hospitalization was significantly shorter in the robotic cohort by approximately 3 days. Although not a specific end point in our study, it is plausible that convalescence may be shorter in the robotic group as well given what appears to be decreased postoperative pain.

Based on our positive experience to date, we consider nearly all patients with mid/distal stricture disease to be appropriate for consideration of the robotic approach with certain caveats. The selection of open vs minimally invasive approach at our institution is ultimately based on referral patterns to our department. Given the retrospective nature of this study, selection bias may have occurred. In addition, several surgeons performed our open operations while the robotic cases were completed by a single surgeon, potentially introducing bias based on surgeon experience. Patients referred to open reconstructive surgeons typically had the procedure performed in open fashion. Patients referred to our minimally invasive surgery (MIS) section were all considered for the robotic approach, unless patients had stricture disease from pelvic radiation or lower extremity bypass grafting (no exclusions encountered during this series). Although the case mix type is not identical in each group, the relative mix appears to be similar, as seen in Tables 1 and 2.

Although not evaluated in our study, MIS reconstructive surgery may be an attractive surgical option for patients relative to open surgery from a cosmetic standpoint. Unlike most extirpative urologic oncology cases that ultimately require an extraction incision, ureteral reconstructive surgery lends itself to completion with just the trocar sites used. Although early reports of the robotic approach have been addressed by others for cases involving malignancy, we have thus far limited our experience to benign indications.^19,20

While we have significant experience with both laparoscopic and robot-assisted urologic procedures, our preferred approach for distal/mid ureteral reimplantation currently favors robotic assistance over pure laparoscopy. We believe the distal ureter dissection and unique angles involved during suturing are aided by robot assistance. In addition, the surgeon's seated position at the console infers comfort advantages over standard laparoscopy. Whether the added cost for the robot is justified was not investigated in this study.

Conclusion

As found in initial reports and confirmed by our study, robot-assisted laparoscopic repair of benign ureteral stricture disease for ureteral reimplantation appears to be feasible. Compared with the open approach, patients undergoing robot-assisted surgery had less blood loss and a shorter hospital stay. Follow-up in both open and robotic groups demonstrated ureteral patency in all patients.

Disclosure Statement

No competing financial interests exist.

Footnotes

Abbreviations Used

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