Buccal Mucosa Graft Ureteroplasty
Buccal mucosa graft (BMG) ureteroplasty is a tissue-sparing upper-tract reconstruction for complex proximal and mid-ureteral strictures that are too long for primary ureteroureterostomy but not extensive enough to justify ileal ureter substitution or renal autotransplantation. Modern robotic series have moved BMG ureteroplasty from an occasional salvage maneuver to a core option in the reconstructive ureteral ladder.[1][2][3]
This page covers BMG ureteroplasty as the main oral-mucosa graft article. For the hybrid transecting configuration, see Augmented Anastomotic Ureteroureterostomy. For pedicled right-sided flap alternatives, see Appendiceal Onlay / Interposition. For long bowel substitution, see Ileal Ureter Substitution.
Why Buccal Mucosa Works
Buccal mucosa was adopted from urethral reconstruction because it behaves unusually well as urinary-tract graft material.[2][4][7]
| Property | Reconstructive Value |
|---|---|
| Panvascular lamina propria | Supports imbibition, inosculation, and neovascularization after placement on a vascular bed |
| Thick resilient epithelium | Tolerates moisture, urine exposure, and mechanical stress better than skin |
| Non-hair-bearing surface | Avoids hair, stone, and infection problems seen with skin-bearing grafts |
| Rapid epithelial healing | Familiar urethroplasty behavior with low scar-contracture tendency compared with skin |
| Easy harvest | Inner cheek access, large harvestable surface, and usually acceptable donor morbidity |
| Long urethroplasty track record | Technique, harvest, defatting, quilting, and donor-site counseling are mature |
The tradeoff is that BMG is a free graft. Unlike appendix or ileum, it has no intrinsic pedicle and depends on the recipient bed, omentum, perinephric fat, or other vascular support for graft take.[2][10][14]
Historical Development
Naude reported buccal mucosal grafts for ureteric lesions in 1999, using patch graft repair with omental wrapping for complex strictures and segmental loss.[7] Kroepfl et al. later reported open BMG treatment of long ureteric strictures, but the operation remained uncommon until robotic reconstruction made precise intracorporeal graft suturing more reproducible.[17]
Zhao et al. reported robot-assisted ureteral reconstruction with buccal mucosa in 2015, followed by CORRUS multi-institutional series that expanded experience from small feasibility cohorts to a 163-patient 10-year robotic cohort.[8][9][10][11][1]
Indications
BMG ureteroplasty is best suited to proximal and mid-ureteral strictures in the tissue-sparing middle ground between simple anastomosis and bowel substitution.[1][2][3][18]
| Indication | Why BMG Fits |
|---|---|
| Proximal or mid-ureteral stricture | Most reported location; avoids distal bladder reconstruction |
| Stricture about 2-8 cm | Too long for tension-free primary UU, usually too short for ileal ureter |
| Failed pyeloplasty / UPJ stricture | Useful when redo pyeloplasty or ureterocalicostomy is not the best geometry |
| Failed endoscopic management | Moves from dilation/incision to tissue reconstruction |
| Failed prior reconstruction | Prior treatment did not independently predict failure in the 163-patient cohort[1] |
| Left-sided stricture | Unlike appendix, BMG is side-independent |
| Need to avoid bowel substitution | Avoids ileal metabolic, mucus, stone, and bowel-anastomosis morbidity |
| Patient with usable oral mucosa | Allows graft harvest without abdominal bowel work |
Distal ureteral strictures are usually better treated with ureteroneocystostomy, psoas hitch, Boari flap, or selective non-transecting side-to-side reimplantation rather than BMG ureteroplasty.[5][6][15]
Contraindications and Caution Zones
- distal ureteral disease where bladder-based reconstruction is simpler and more durable,
- pan-ureteral or very long strictures where ileal substitution is more realistic,
- malignant ureteral disease requiring oncologic excision,
- active oral mucosal disease such as leukoplakia, lichen planus, submucous fibrosis, or severe scarring,
- inability to provide a vascularized graft bed or wrap,
- high-risk irradiated tissue without omental or alternative vascular support,
- oral harvest limitations from prior graft harvest, limited mouth opening, or patient preference.
Radiation-induced ureteral strictures deserve special caution. In the CORRUS radiation-induced stricture cohort, BMG ureteroplasty was used in only 1 of 35 ureteral units; most repairs used reimplantation strategies. When BMG is used in irradiated fields, vascular reinforcement is especially important.[12]
Preoperative Planning
Planning should define anatomy, function, and graft/bed feasibility.
| Question | Planning Tool |
|---|---|
| Where are the stricture limits? | CT urogram, MR urogram, retrograde/antegrade pyelography, ureteroscopy |
| Is it narrowed or obliterated? | Retrograde/antegrade contrast, ureteroscopic passage, guidewire behavior |
| Is the renal unit salvageable? | MAG3/DTPA renography, cortical thickness, symptoms, infection history |
| Which configuration is needed? | Non-transecting onlay for patent lumen; augmented anastomotic for obliterated core |
| Is oral mucosa suitable? | Oral exam, prior harvest history, mouth opening, mucosal disease screen |
| Can the graft be vascularly supported? | Omentum availability, perinephric fat, prior abdominal surgery |
Ureteral rest, nephrostomy drainage, or preoperative stenting may be used depending on infection, obstruction, and the need to delineate anatomy, but chronic stent-related inflammation can also obscure the true stricture biology.
Graft Harvest
BMG harvest is usually performed from the inner cheek, often simultaneously with robotic exposure by a second team.
Key steps:
- Evert the cheek and mark Stensen's duct.
- Mark a graft long enough to cover the ureteral defect, usually about 1 cm wide.
- Infiltrate for hemostasis and hydrodissection.
- Harvest sharply, avoiding parotid duct injury.
- Defat minimally on the back table, preserving lamina propria.
- Close the donor site or leave it open depending on surgeon preference.
For longer defects, bilateral cheek grafts or composite grafts may be used.[13] In a randomized urethroplasty donor-site trial, nonclosure was noninferior to closure for oral pain and was associated with lower pain scores, making nonclosure a reasonable donor-site strategy.[5]
Robotic Operative Technique
Exposure and localization
- Position similarly to robotic pyeloplasty or upper/mid-ureteral reconstruction.
- Identify the ureter proximal to the stricture.
- Preserve periureteral adventitia and blood supply.
- Use intraoperative flexible ureteroscopy to define the distal stricture extent and transilluminate the ureter.
- Use ICG/Firefly selectively to assess ureteral perfusion and orientation.[6][13]
Non-transecting onlay
This is the most common configuration in early robotic series.[10][11]
- Incise the ureter longitudinally across the stricture.
- Do not transect the ureter.
- Extend the ureterotomy until healthy mucosa and lumen are visible at both ends.
- Place the BMG as anterior/ventral or posterior/dorsal onlay with mucosa facing the lumen.
- Suture the graft to ureteral edges using running or interrupted absorbable 4-0 or 5-0 suture.
- Place a double-J stent across the reconstruction.
- Wrap with omentum or perinephric fat.
Augmented anastomotic BMG ureteroplasty
Use this when part of the stricture is obliterated but the remaining segment can be preserved as a plate.
- Excise the obliterated segment.
- Reanastomose the posterior ureteral wall primarily.
- Place BMG as an anterior onlay to complete the circumference.
- Stent and wrap as above.
This hybrid operation is covered in more detail in Augmented Anastomotic Ureteroureterostomy.
Omental or fat wrap
Omental wrap is a major adjunct because BMG has no intrinsic blood supply. In the initial CORRUS series, omentum was used in 95% of cases.[10] The wrap provides vascularity, stabilizes the graft, separates the repair from surrounding scar, and may blunt inflammation.
When omentum is difficult to mobilize, perinephric fat wrap is a reported alternative. Jiang et al. reported comparable outcomes with perinephric fat wrapping and omental wrapping, with faster bowel function recovery in the perinephric-fat group.[14]
Anterior vs Posterior Onlay
| Approach | Advantages | Tradeoffs |
|---|---|---|
| Anterior / ventral onlay | Technically straightforward, no ureter rotation, familiar robotic exposure | Relies on omentum/fat wrap to provide external vascular support |
| Posterior / dorsal onlay | Graft can rest against psoas or retroperitoneal vascular bed | Requires more ureter rotation and posterior exposure |
Available reviews have not shown a clear efficacy or complication difference between anterior and posterior onlay, so the choice is usually anatomy- and surgeon-dependent.[3]
Outcomes
| Series | Year | N | Approach | Typical Stricture Length | Success / Key Finding |
|---|---|---|---|---|---|
| Naude | 1999 | 6 | Open | Variable | All patent after BMG patch repair with omental wrap[7] |
| Kroepfl et al. | 2010 | 7 | Open | Long-segment | 71.4% success at 18 months[17] |
| Zhao et al. | 2015 | 4 | Robotic | Not specified | 100% success at 15.5 months[8] |
| Lee et al. | 2017 | 12 | Robotic | Median 3 cm | 83.3% success at 13 months[9] |
| Zhao et al. CORRUS | 2018 | 19 | Robotic | Median 4 cm | 90% success at 26 months; 79% onlay and 21% augmented anastomotic[10] |
| Lee et al. CORRUS update | 2021 | 54 | Robotic | Median 3 cm | 87.0% success at 27.5 months; major complications 5.6%[11] |
| Heijkoop and Kahokehr systematic review | 2021 | 72 procedures | Open/robotic | Variable | 91.6% overall success; Clavien-Dindo grade 3 or higher complication rate 5%[16] |
| Chao et al. 10-year cohort | 2025 | 163 | Robotic | Median 3 cm | 92.0% free from additional intervention at median 29 months[1] |
In the 163-patient 10-year cohort, 150 of 163 patients (92.0%) remained free from additional interventions at median 29-month follow-up. Median time to failure was 10.2 months, and no patient- or disease-specific factor, including stricture length, prior treatment, or onlay versus augmented anastomotic technique, independently predicted failure.[1]
Comparison with ileal ureter
A 2023 meta-analysis comparing oral mucosal graft ureteroplasty with ileal ureter replacement found pooled success of 94.9% for oral mucosal graft ureteroplasty versus 85.8% for ileal ureter. Mean stricture length was much shorter in the graft group (3.73 cm vs 11.55 cm), but graft ureteroplasty also had shorter hospital stay and lower low-grade, high-grade, and long-term complication rates.[18]
The right interpretation: BMG is not replacing ileal ureter for pan-ureteral disease. It is reducing unnecessary ileal substitution for focal strictures that can be reconstructed with graft augmentation.
Complications
Recipient site
| Complication | Signal |
|---|---|
| Stricture recurrence | Main failure mode; 8-17% across series, median time to failure about 10 months in the largest cohort[1][11] |
| Urine leak / urinoma | Uncommon; usually managed with drainage, stent duration, nephrostomy, or intervention |
| UTI / pyelonephritis | Variable, treated with antibiotics and drainage when needed |
| Clavien-Dindo grade 3 or higher complication | About 5-5.6% in systematic review and CORRUS update[11][16] |
| Graft contracture or failure | Usually presents as recurrent obstruction |
Oral donor site
Most donor-site data come from urethroplasty, where harvest technique is the same and evidence is much larger.[5][19][20][21]
| Morbidity | Typical Course |
|---|---|
| Oral pain | Common early, usually improves over weeks |
| Perioral numbness / sensory change | Can persist in a minority; often not bothersome |
| Mouth tightness or reduced opening | Usually improves, occasionally persistent |
| Eating/drinking difficulty | Most prominent in first days to weeks |
| Speech changes | Usually transient |
| Bleeding | Uncommon but possible immediately post-harvest |
Prospective donor-site data suggest overall oral health usually recovers, while randomized donor-site closure data support nonclosure as a reasonable pain-sparing option.[5][19]
Adjuncts
| Adjunct | Role |
|---|---|
| Flexible ureteroscopy | Defines stricture edge and can transilluminate the target ureter |
| ICG near-infrared fluorescence | Assesses ureteral perfusion and helps identify viable tissue[6] |
| Omental wrap | Most established vascular support for the free graft[10] |
| Perinephric fat wrap | Alternative vascularized support when omentum is difficult[14] |
| Double-J stent | Maintains luminal alignment during healing |
| Drain | Detects or controls early leak |
Buccal vs Lingual Mucosa
Lingual mucosa graft (LMG) is an alternative oral graft source. Ureteral LMG series report strong early outcomes, including posteriorly augmented anastomotic LMG ureteroplasty.[23] Urethroplasty donor-site comparisons show broadly similar success but different morbidity patterns: LMG may produce more early speech, eating, and taste disturbance, while BMG may produce more early mouth tightness.[22]
In practice, BMG remains the default oral graft for many reconstructive teams because of familiarity, surface area, and mature urethroplasty experience. LMG is useful when buccal harvest is limited, exhausted, or undesirable.
Special Settings
Radiation-induced ureteral stricture
Radiation strictures are ischemic, fibrotic, and less forgiving. BMG can be considered selectively, but graft take is only as good as the vascular bed. CORRUS radiation data show reconstructive feasibility overall, but BMG was used rarely in that cohort.[12] If BMG is used after radiation, omental or other vascular support should be considered essential.
Failed prior reconstruction
Prior reconstruction does not preclude BMG ureteroplasty. In the largest cohort, nearly half of patients had prior stricture treatment, and prior treatment was not an independent predictor of failure.[1]
Left-sided strictures
BMG is side-independent and therefore particularly valuable when appendiceal flap is not available because of laterality, prior appendectomy, or competing Mitrofanoff/MACE needs.
Emerging Alternatives
Vesical mucosal graft
Robot-assisted vesical mucosal graft ureteroplasty has been reported as a fully intracorporeal option that avoids oral harvest. Early 2025 data describe 14 patients with 100% success at short follow-up and no Clavien-Dindo grade 3 or higher complications, but experience is still very limited.[24]
Tissue-engineered grafts
Small-intestinal submucosa, scaffold-based repairs, extracellular vesicles, organoid systems, and cell-seeded constructs remain investigational. They are not substitutes for BMG, appendix, or ileal ureter in current clinical practice.[3][4]
Decision Framework
Choose BMG ureteroplasty when:
- the stricture is proximal or mid ureter,
- the length is roughly 2-8 cm,
- primary ureteroureterostomy would be tight or ischemic,
- distal reimplantation is not the right geometry,
- appendix is unavailable, left-sided, too short, or needed elsewhere,
- the kidney is worth preserving,
- omental or fat support can be provided.
Choose appendiceal flap when a right-sided moderate stricture has a healthy appendix and a pedicled flap is preferred. Choose ileal ureter when disease length exceeds graft/flap reconstruction. Choose renal autotransplantation or TUU only when native-tissue, graft, bladder, and bowel options are poorly suited.
Operative Pearls
- Use BMG to avoid unnecessary ileal ureter, not to rescue pan-ureteral disease.
- Define the distal stricture edge with ureteroscopy whenever possible.
- Incise until healthy ureteral mucosa is seen at both ends.
- Do not over-defat the graft; preserve the lamina propria.
- Make the graft broad enough; narrow grafts become narrow repairs.
- Omentum or perinephric fat is part of the operation, not garnish.
- Counsel about oral morbidity honestly, even though most symptoms improve.
- Most failures declare within the first 1-2 years, but longer surveillance is still prudent.
References
1. Chao BW, Raver M, Lin JS, et al. Robotic buccal mucosa graft ureteroplasty: a decade of experience from a multi-institutional cohort. Urology. 2025;197:174-179. doi:10.1016/j.urology.2024.11.059.
2. Bello D, Van Shufflin M, Hofer MD. Expanding the armamentarium: perspectives on buccal mucosal grafts and appendiceal flaps in ureteral reconstructive surgery. J Clin Med. 2025;14(21):7681. doi:10.3390/jcm14217681.
3. Xiong S, Wang J, Zhu W, et al. Onlay repair technique for the management of ureteral strictures: a comprehensive review. Biomed Res Int. 2020;2020:6178286. doi:10.1155/2020/6178286.
4. Sterling J, Hecksher D, Hayden C, et al. Buccal mucosa a narrative review: how does it work, how is it used, what is coming next. Urology. 2026. doi:10.1016/j.urology.2026.03.015.
5. Soave A, Dahlem R, Pinnschmidt HO, et al. Substitution urethroplasty with closure versus nonclosure of the buccal mucosa graft harvest site: a randomized controlled trial with a detailed analysis of oral pain and morbidity. Eur Urol. 2018;73(6):910-922. doi:10.1016/j.eururo.2017.11.014.
6. Chao BW, Lee M, Eun DD. Robotic multiport buccal mucosa graft ureteroplasty: tips and tricks. J Endourol. 2025;39(S1):S52-S59. doi:10.1089/end.2024.0342.
7. Naude JH. Buccal mucosal grafts in the treatment of ureteric lesions. BJU Int. 1999;83(7):751-754. doi:10.1046/j.1464-410x.1999.00019.x.
8. Zhao LC, Yamaguchi Y, Bryk DJ, Adelstein SA, Stifelman MD. Robot-assisted ureteral reconstruction using buccal mucosa. Urology. 2015;86(3):634-638. doi:10.1016/j.urology.2015.06.006.
9. Lee Z, Waldorf BT, Cho EY, et al. Robotic ureteroplasty with buccal mucosa graft for the management of complex ureteral strictures. J Urol. 2017;198(6):1430-1435. doi:10.1016/j.juro.2017.06.097.
10. Zhao LC, Weinberg AC, Lee Z, et al. Robotic ureteral reconstruction using buccal mucosa grafts: a multi-institutional experience. Eur Urol. 2018;73(3):419-426. doi:10.1016/j.eururo.2017.11.015.
11. Lee Z, Lee M, Koster H, et al. A multi-institutional experience with robotic ureteroplasty with buccal mucosa graft: an updated analysis of intermediate-term outcomes. Urology. 2021;147:306-310. doi:10.1016/j.urology.2020.08.003.
12. Asghar AM, Lee Z, Lee RA, et al. Robotic ureteral reconstruction in patients with radiation-induced ureteral strictures: experience from the Collaborative of Reconstructive Robotic Ureteral Surgery. J Endourol. 2021;35(2):144-150. doi:10.1089/end.2020.0643.
13. Arora S, Campbell L, Tourojman M, et al. Robotic buccal mucosal graft ureteroplasty for complex ureteral stricture. Urology. 2017;110:257-258. doi:10.1016/j.urology.2017.06.037.
14. Jiang Y, Yang C, Fang L, et al. The application of the "perinephric fat wrapping" technique with oral mucosal graft for the management of ureter repair and reconstruction. World J Urol. 2024;42(1):528. doi:10.1007/s00345-024-05230-8.
15. de'Angelis N, Schena CA, Marchegiani F, et al. 2023 WSES guidelines for the prevention, detection, and management of iatrogenic urinary tract injuries during emergency digestive surgery. World J Emerg Surg. 2023;18(1):45. doi:10.1186/s13017-023-00513-8.
16. Heijkoop B, Kahokehr AA. Buccal mucosal ureteroplasty for the management of ureteric strictures: a systematic review of the literature. Int J Urol. 2021;28(2):189-195. doi:10.1111/iju.14426.
17. Kroepfl D, Loewen H, Klevecka V, Musch M. Treatment of long ureteric strictures with buccal mucosal grafts. BJU Int. 2010;105(10):1452-1455. doi:10.1111/j.1464-410X.2009.08994.x.
18. You Y, Gao X, Chai S, et al. Oral mucosal graft ureteroplasty versus ileal ureteric replacement: a meta-analysis. BJU Int. 2023;132(2):122-131. doi:10.1111/bju.15994.
19. Desai D, Joshi S, Ravichandran K, et al. Donor site morbidity and impact on oral health following buccal mucosal graft harvesting for urethroplasty: a prospective study. World J Urol. 2025;43(1):531. doi:10.1007/s00345-025-05898-6.
20. Castagnetti M, Ghirardo V, Capizzi A, Andretta M, Rigamonti W. Donor site outcome after oral mucosa harvest for urethroplasty in children and adults. J Urol. 2008;180(6):2624-2628. doi:10.1016/j.juro.2008.08.053.
21. Wood DN, Allen SE, Andrich DE, Greenwell TJ, Mundy AR. The morbidity of buccal mucosal graft harvest for urethroplasty and the effect of nonclosure of the graft harvest site on postoperative pain. J Urol. 2004;172(2):580-583. doi:10.1097/01.ju.0000132846.01144.9f.
22. Lumen N, Vierstraete-Verlinde S, Oosterlinck W, et al. Buccal versus lingual mucosa graft in anterior urethroplasty: a prospective comparison of surgical outcome and donor site morbidity. J Urol. 2016;195(1):112-117. doi:10.1016/j.juro.2015.07.098.
23. Fan S, Yin L, Yang K, et al. Posteriorly augmented anastomotic ureteroplasty with lingual mucosal onlay grafts for long proximal ureteral strictures: 10 cases of experience. J Endourol. 2021;35(2):192-199. doi:10.1089/end.2020.0686.
24. Morra I, Busacca G, Ornaghi PI, et al. Vesical mucosal graft for the treatment of ureteral strictures with a total robot-assisted approach. Eur Urol. 2025. doi:10.1016/j.eururo.2025.04.016.