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 described in 2024 by Kam, Emmanuel, Del Giudice, Shabbir, and Nair (Guy's Hospital, London) in a single robotic case in Urology Video Journal.[1] Evidence is limited to this n = 1 report; the page is included so the technique is discoverable for the salvage scenarios in which it is most likely to be considered.
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 minimizes anastomotic tension while providing a vascularized bed for the ventral graft.
The posterior plate is then augmented with a ventral BMG onlay, restoring normal caliber without the bowel-related morbidity of an ileal interposition or the need for 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 (initial robotic diverticulectomy and ureteral reimplantation for non-muscle-invasive urothelial cancer of a bladder diverticulum, then a revision reimplantation with psoas hitch).
- Stent could not be passed antegrade or retrograde; the patient was nephrostomy-dependent.
- Long Boari flap precluded by limited bladder capacity (300–400 mL).
- Patient-driven 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.
The technique is positioned for revision distal ureteral strictures where there is still healthy proximal ureter but the stricture length and position preclude direct re-anastomosis, and where bowel interposition or autotransplantation are undesirable.[1]
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 |
| 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 2–3 (drain out POD 1; nephrostomy out POD 2) |
| Cystogram + catheter removal | Day 14, no leak |
| Stent removal + retrograde pyelogram | 6 weeks, normal caliber, no stricture |
| MAG-3 renogram | 3 months, normal drainage, no obstruction |
| Renal function | Preserved |
Follow-up reported in the original case is short (3 months); long-term durability data are not yet available.[1]
Where It Fits
- Closest neighbor in the upper-tract atlas is BMG Onlay Ureteroplasty — same graft material, but MANTA specifically pairs the onlay with a non-transecting muco-mucosal posterior-plate anastomosis to a prior bladder anastomosis, so it is best read as a salvage configuration for distal strictures involving the bladder anastomosis rather than the standard mid- or proximal-ureteral onlay.
- Closest neighbor by clinical scenario is Non-Transecting Reimplantation and Boari Flap with Psoas Hitch. MANTA is the option when the residual ureter is too short for tension-free reimplant, the bladder is too small for a long Boari, and the patient declines bowel interposition or autotransplantation.
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.16067.
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.15692.