Buccal mucosal graft ureteroplasty: The new normal in ureteric reconstructive surgery – Our initial experience with the laparoscopic and robotic approaches

Abstract

Introduction:

Upper ureteric stricture is always a challenging case to treat for any urologist. Due to chronic inflammation and multiple interventions, it becomes a complex entity to treat. Buccal Mucosal Graft (BMG) Ureteroplasty is a reconstructive surgery used to treat upper ureteric stricture but the results and experience with this modality is less explored so far. We present here our study of 16 cases of BMG ureteroplasty and its outcomes done by the laparoscopic and robotic approaches.

Patients and Methods:

We analysed 16 cases of BMG ureteroplasty, which were performed both laparoscopically and robotically. All these cases were long ureteric strictures, not amenable to excision or endoscopic intervention. We performed using an onlay BMG without complete mobilisation of the ureter. The omentum or nearby fat was used as a bed for onlay BMG.

Results:

All 16 patients underwent onlay ureteroplasty. The reconstructed ureter was wrapped with omentum in nine of the cases, while in seven patients, nearby fat was used. The median stricture length was 5.28 cm, and the median operative time was 143.5 min. The mean operative time was 143.5 min. 15 of 16 (93.75%) cases were successfully clinically and radiologically on follow-up.

Conclusion:

Long-segment upper ureteric strictures are a difficult entity to operate on. BMG ureteroplasty is a safe and effective way of managing such strictures. Robot-assisted ureteroplasty provides the benefits of improved ergonomics, easy manoeuvrability and precision surgery to the patients. Our experience with both laparoscopic and robotic ureteroplasty would encourage urologists all over to use BMG ureteroplasty as an effective long-term procedure for ureteral reconstruction.

INTRODUCTION

Proximal ureteric strictures are a complex and challenging entity to treat in reconstructive urology. The aetiology of these strictures is varied, such as trauma, ischaemia, instrumentation and infection.[1,2] Long-segment ureteric strictures often necessitate the use of advanced surgical techniques such as renal descensus, ileal ureter replacement, Boari flap, ureterocalicostomy and autotransplantation of the kidney.[3] An alternative to these complex procedures is buccal mucosal graft (BMG) ureteroplasty, which is a less complex and less morbid surgery with excellent outcomes. BMG has been used in urethral surgeries with good efficacy; hence, it is only natural to extend the benefits of BMG in ureteric reconstruction.[4] All three approaches, namely open, laparoscopic and robotic-assisted surgeries, can be used for reconstruction. The extension of advantages of robotic surgery, such as higher magnification, improved dexterity, precise suture and three-dimensional vision, has further reduced the morbidity associated with this surgery.[5,6] We, here, present our experience of a retrospective study of 16 buccal mucosal ureteral reimplantations done by both laparoscopic and robotic approaches.

MATERIALS AND METHODS

A retrospective analysis of patients who underwent BMG ureteroplasty between January 2019 and November 2022 was performed. Inclusion criteria involved proximal ureteral stricture, where excision and anastomosis were not possible. Pre-operative workup included detailed history, blood investigations and computed tomography (CT) urography. Retrograde pyelography and ureteroscopy (URS) were performed under general anaesthesia to assess the exact stricture length. Those patients with percutaneous nephrostomy (PCN) underwent nephrostogram. This helped to know the exact length of the stricture to harvest BMG, which is an important step in this surgery. The procedures were performed both laparoscopically and robotically (Da Vinci^® Xi Surgical Systems, Intuitive Surgical, Sunnyvale, USA). Patients were positioned in the modified lateral decubitus position with port placement like in pyeloplasty. Figure 1 shows port placement for Robotic and Laparoscopic Surgery for right side. Patients’ oral cavity was separately cleaned and draped for BMG harvest. The stricture was measured, and the BMG was harvested accordingly. A ureterotomy was made along the length of the stricture over the double-J (DJ) stent. The BMG was sewn to the ureteric edges as an onlay patch over the DJ stent. An omental wrap or perinephric fat pad was wrapped over the ureteric repair area for additional blood supply. Follow-up included the removal of DJ stent at 8 weeks. Post-operative CT urography was done at 1 month. Ultrasound kidney, ureter and bladder and serum creatinine were performed at 3-, 6- and 12-month intervals. The study complies completely with the ethical standards of the Helsinki Declaration, and informed consent was taken. Statistical analysis was done using the IBM SPSS Statistics , Version 24.0, Armonk, NY IBM Corp.

Figure 1.

Port placement for robotic and laparoscopic surgeries for the right side. For the left side, 5-mm epigastric port was not placed

RESULTS

A total of 16 cases were included in our study, of which 9 (56.3%) were operated laparoscopically, and in 7 (43.7%), robot-assisted surgery was done. The mean age was 35.6 years. Eleven patients had a history of complicated ureteric stone surgery by URS or retrograde intrarenal surgery. Two patients had a history of open surgery for stone disease, while three patients had a history of genitourinary tuberculosis (GUTB), post-antitubercular treatment. The average length of ureteric stricture was 5.28 cm. The mean follow-up time was 23 (4–38) months. The mean operative time was 143.5 min, and the mean blood loss was 34.6 ml. The average length of harvested BMG was 6.2 cm. Stone was present in the ureteric lumen/mucosa in two cases. The omentum was wrapped in 9 of 16 cases, while in seven cases, we used perirenal fat as the vascular bed. The average drain output was 30 ml with no urinary leakage. Foley was removed on post-operative day 2, and the drain was removed on post-operative day 3. One patient persisted in having drain output for 7 days; however, it was serous only and not urine. The DJ stent was removed after 8 weeks. Post-operative complications were none except in one patient who had persistent drain output for 7 days. CT urography at 1 month showed patent ureteric lumen in all 16 patients. During the follow-up, 15 out of 16 patients had no hydronephrosis with normal renal pelvis on imaging at 3, 6 and 12 months. Serum creatinine remained stable over time, indicating no impairment of renal function. There were no complication related to graft harvested site in our study. Outcomes in laparoscopic and robotic cases were comparable, with no significant difference. Out of 16, one patient developed a stricture again at 11 months. This patient had a history of GUTB, and stricture was formed below the original ureteroplasty site. This patient was subsequently treated by PCN and ileal replacement of the ureter. The success rate for our study was 93.75%.

Table 1 summarises the demographics and findings of our study. Figure 2 shows a patient with upper ureteric stricture operated with robotic ureteroplasty along with post-operative outcome.

Table 1.

Demographic profile of patients

Patient number	Age (years)	Previous surgery/morbidity	Duration of initial surgery (weeks)	Length of stricture (cm)	Operative time (min)	Duration of the drain (days)	Blood loss (mL)	Approach (laparoscopy/robotic)
1	28	URS	5	4	130	2	20	Laparoscopy
2	30	TB	36	7.5	145	7	20	Laparoscopy
3	32	OPEN	18	4	160	2	30	Laparoscopy
4	34	RIRS	15	6	140	2	35	Laparoscopy
5	42	TB	25	4.5	125	2	30	Laparoscopy
6	35	RIRS	40	3.5	115	2	35	Laparoscopy
7	41	TB	32	5.5	175	2	45	Laparoscopy
8	40	RIRS	15	6	160	2	50	Laparoscopy
9	40	URS	5	7	130	2	45	Robotic
10	29	RIRS	8	6.8	135	2	25	Laparoscopy
11	30	OPEN	11	6	140	2	30	Robotic
12	35	URS	10	5.5	140	2	50	Robotic
13	36	RIRS	6	4	138	1	40	Robotic
14	34	RIRS	5	4.5	148	2	30	Robotic
15	45	RIRS	5	4.8	155	2	40	Robotic
16	40	URS	9	5	160	1	30	Robotic
Mean value	35.6	-		5.28	143.5	2.18	34.6	Laparoscopy - 9 Robotic - 7

URS: Ureteroscopy, TB: Tuberculosis, RIRS: Retrograde intrarenal surgery, OPEN: Open ureterolithotomy

Figure 2.

(a) Computed tomography urography showing the right upper ureteric stricture. (b) Retrograde pyelography showing the right upper ureteric stricture of about 5 cm size. (c) Harvested buccal mucosal graft (BMG). (d) Intraoperative picture of ureterotomy incision with graft being applied. (e) Buccal mucosal graft fixed over the strictured segment. (f) Follow-up at 1 year showing patent ureteric lumen

DISCUSSION

Upper ureteric stricture is always a challenge to treat for any urologist. The complexity of these strictures can be attributed to the fibrosis, inflammation and multiple procedures in these cases. Ileal interposition is often complicated with anastomotic strictures, pyelonephritis and chronic renal failure with autotransplantation is also a complex procedure in itself with vascular complications.[5,7,8] Amongst the reconstructive procedures described, BMG ureteroplasty is one of the less morbid ways to treat these strictures. Naude, in 1999, first described the use of BMG for ureteral reconstruction with considerable success.[5,9] In a study by Pandey et al., three patients underwent onlay BMG ureteroplasty with a 100% success rate.[6,10] Lee et al. had a success rate of 83.3% on a median follow-up of 13 months with robotic BMG ureteroplasty.[5] Ganpule et al. described the only inlay procedure for ureteroplasty.[11] In a study by Zhao et al. on robotic BMG ureteroplasty for proximal ureteral strictures, there was no stricture formation on a follow-up of 15 months.[12,13] Over the years, BMG ureteroplasty has become one of the important surgical modality for urologists to deal with upper ureteric stricture.[14,15] The buccal mucosa has the advantages of being easily harvestable and easy to handle with good graft uptake and minimal donor-site complications, which has led to its worldwide acceptance as a graft for ureteroplasty.[16,17] The buccal mucosa has stood the test of time with good graft take-up rate, patency and results for long segment ureteric loss.[18,19,20] We have used the onlay approach of BMG ureteroplasty in our study, which allows maximum preservation of the blood supply of the ureter as it avoids the mobilisation of the ureter and ureterolysis while performing reconstructive surgery. The omentum or the perirenal fat can be used to provide the vascular bed in this surgery with good outcomes. Strictures as long as 11 cm have been reported to be treated by BMG ureteroplasty. Our study had a mean stricture length of 5.28 cm. With the use of minimal access surgery, BMG ureteroplasty has a more precise and even less morbid procedure. Most of the literature describes the results of open BMG ureteroplasty with a very few studies for robot-assisted BMG ureteroplasty. The robotic approach provides delicate suturing, better magnification with an excellent view for precise surgery, which is certainly a boon in these complex surgeries.[5,10,21] In our study, we have used minimal invasive surgery in all our cases with seven robot-assisted ureteroplasty. With a success rate of above 90% in our study, we favour more frequent use of BMG ureteroplasty for complex ureteric strictures.

CONCLUSION

The management of long-segment ureteric strictures needs an in-depth understanding and meticulous approach for a favourable outcome. BMG ureteroplasty has emerged as a viable option in recent years with excellent outcomes. More institutional studies with bigger sample sizes are needed to advocate for the routine use of BMG ureteroplasty in managing complex long-segment ureteric strictures.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.