Muco-Mucosal Anastomotic Non-Transecting Augmentation (MANTA) Ureteroplasty
MANTA ureteroplasty is a salvage reconstruction for revision distal ureteral strictures that extend into a prior bladder anastomosis, adapted directly from the MANTA urethroplasty and MsANTA / Joshi Step techniques. The strictured segment is incised and spatulated without transection, a muco-mucosal posterior plate is constructed by suturing healthy proximal ureteral mucosa to healthy bladder mucosa, and a ventral buccal mucosa graft (BMG) onlay completes the lumen over a double-J stent.[1]
The technique was first reported by Kam, Emmanuel, Del Giudice, Shabbir, and Nair (Guy's Hospital, London) in a single robotic case published in the March 2025 issue of Urology Video Journal.[1] Evidence is limited to this n = 1 report.
For the standard onlay technique, see Buccal Mucosa Graft Ureteroplasty. For other salvage options after failed reimplant, see Boari Flap and Psoas Hitch, Ileal Ureter Substitution, and Renal Autotransplantation.
Conceptual Origin
MANTA ureteroplasty borrows two principles from the bulbar-urethral non-transecting augmented family:[1][2][3]
- Non-transection preserves residual blood supply crossing the strictured segment from the distal end of the repair.
- Muco-mucosal posterior-plate anastomosis between healthy proximal mucosa and healthy distal mucosa is intended to minimize anastomotic tension and to reconstruct the posterior luminal wall beneath the ventral graft.
The posterior plate is then augmented with a ventral BMG onlay, restoring caliber without the bowel-related morbidity of an ileal interposition and without a long Boari flap when bladder capacity is inadequate.[1]
Indications
The original report was a single robotic case with the following profile:[1]
- Recurrent distal ureteral stricture extending into the bladder anastomosis after two prior failed reconstructions (the abstract describes diverticulectomy with Boari-flap reimplantation for urothelial cancer, followed by revision ureteric reimplantation).
- Stent could not be passed antegrade or retrograde; the patient was nephrostomy-dependent.
- Prior Boari flap: The reported patient had undergone Boari-flap reimplantation and revision before MANTA.[1]
- Patient preference for kidney-preserving reconstruction over nephrectomy or ileal interposition.
- Salvageable kidney function: DMSA 34% on the affected side, creatinine 125 µmol/L, eGFR 50 mL/min.
In the single published case, MANTA was used for a revision distal stricture with healthy proximal ureter; evidence is insufficient to determine whether stricture length or position that precludes direct re-anastomosis, or the undesirability of bowel interposition or autotransplantation, should be used as selection criteria.[1]
When recurrent urothelial cancer is suspected at a ureteral stricture, evaluate it before choosing non-excisional reconstruction. For suspected upper-tract urothelial carcinoma, the AUA/SUO 2023 guideline recommends cystoscopy and contrast upper-tract imaging with delayed images , followed by diagnostic ureteroscopy with biopsy of identified lesions and upper-tract cytologic washing .[5]
Technique
The published case was performed robotically.[1]
| Step | Detail |
|---|---|
| Positioning | Supine Trendelenburg 24°, table rotated 10° to the right |
| Port placement | Camera port 2 cm above umbilicus; three robotic ports 8 cm apart in an oblique line between the right ASIS and left costal margin; two assistant ports (12 mm AirSeal + 5 mm) |
| Exposure | Medialize the colon and expose the strictured segment |
| Localization | Inject ICG via the existing nephrostomy to confirm ureteral course and identify the narrow lumen within the fibrotic segment |
| Stricturotomy | Incise and spatulate the stricture without transecting; the original case showed a 4 cm heavily fibrotic segment with minimal residual lumen extending from the distal ureter into the bladder anastomosis |
| Posterior plate | Place corner stay sutures, then run a 5-0 Vicryl Plus muco-mucosal anastomosis from healthy proximal ureteral mucosa to healthy bladder mucosa; preserves residual blood supply and offloads tension |
| Buccal donor site (separate robotic BMG series) | Identify and mark Stensen’s duct before harvest; dissect carefully around the duct and lower lip to avoid ductal stenosis, salivary leakage, and sensory loss.[4] |
| Augmentation | Harvest BMG, trim to size, lay over the reconstructed posterior plate, and suture with 5-0 Vicryl Plus over a 6 Fr × 26 cm double-J stent |
| Coverage | Wrap with healthy retroperitoneal and pericolic fat |
Reported Outcome
| Endpoint | Result |
|---|---|
| Length of stay | Discharge POD 3 in the published abstract |
| Cystogram + catheter removal | 4 weeks in the published abstract |
| Stent removal + retrograde pyelogram | 6 weeks, normal caliber, no stricture |
| MAG-3 renogram | 3 months, normal drainage, no obstruction |
| Renal function | Preserved |
Complications. A separate retrospective series of 39 robotic BMG ureteroplasties reported complications within 30 days in 8/39 patients (21%), including four urinary tract infections, one anastomotic fistula requiring continued nephrostomy drainage, and one stent migration requiring repositioning. Four of 39 patients underwent augmented BMG repair.[4]
Follow-up reported in the original case is short (3 months); long-term durability data are not yet available.[1]
Where It Fits
- BMG Onlay Ureteroplasty uses the same graft material. MANTA pairs the onlay with a non-transecting muco-mucosal posterior-plate anastomosis to a prior bladder anastomosis. It is a salvage configuration for distal strictures involving the bladder anastomosis. Standard BMG onlay is generally used for proximal or mid-ureteral strictures; a four-center BMG ureteroplasty series also considered selected distal lesions with healthy ureter below the stricture, using onlay or augmented repair.[4]
- Non-Transecting Reimplantation and Boari Flap with Psoas Hitch address similar clinical scenarios. MANTA has been described as a salvage configuration for selected anatomy in a single case.
Videos
References
1. Kam J, Emmanuel A, Del Giudice F, Shabbir M, Nair R. Muco-mucosal anastomotic non-transecting augmentation (MANTA) ureteroplasty. Urol Video J. 2025;25:100320. doi:10.1016/j.urolvj.2024.100320.
2. Marks P, Dahlem R, Janisch F, Klemm J, Kühnke L, König F, et al. Mucomucosal anastomotic non-transecting augmentation (MANTA) urethroplasty: a ventral modification for obliterative strictures. BJU Int. 2023;132(4):444-451. doi:10.1111/bju.16112.
3. Joshi P, Bandini M, Kulkarni SB. Mucosal-sparing augmented non-transected anastomotic (MsANTA) urethroplasty: a step forward in ANTA urethroplasty. BJU Int. 2022;130(1):133-136. doi:10.1111/bju.15734.
4. Bourillon A, McGuire BB, Pinar U, et al. "Robot-assisted buccal mucosa graft ureteroplasty for ureteral stricture: a European multicenter case series." Eur Urol Open Sci. 2026;83:166-172. doi:10.1016/j.euros.2025.12.007
5. Coleman JA, Clark PE, Bixler BR, et al. "Diagnosis and management of non-metastatic upper tract urothelial carcinoma: AUA/SUO guideline." J Urol. 2023;209(6):1071-1081. doi:10.1097/JU.0000000000003480