Grafts in Genitourinary Reconstruction
A free tissue graft is transferred without a vascular pedicle and must acquire support from its recipient bed. A flap arrives with its own blood supply.
Graft Take: Imbibition and Inosculation
Imbibition (0–48 hours)
Initially, fluid and nutrients diffuse from the recipient bed into the graft, which is edematous and pale during this phase. Fluid collecting between graft and bed interrupts this exchange.[12] The initial diffusion phase is commonly described over the first one to two days.[12]
Inosculation (48 hours – 1 week)
Inosculation describes connections between graft and recipient vessels; neovascularization includes ingrowth of new host vessels. These processes overlap. The classic Converse experiment demonstrated vascular entry by 48 hours in rat skin grafts. A viable skin graft usually turns pink as perfusion returns over roughly the first week.[2]
Factors Affecting Graft Take
| Factor | Practical implication |
|---|---|
| Recipient-bed vascularity | Assess actual viable tissue; marked scarring, ischemia or radiation injury may require vascularized reconstruction |
| Contact and drainage | Prevent hematoma, seroma and other collections that separate graft from bed; use appropriate fixation, including quilting where indicated |
| Shear | Plan support and immobilization by operation and anatomical site; 48–72 hours is not a fixed regimen |
| Infection and tissue viability | Debride nonviable tissue and control infection; colonization alone is not synonymous with invasive infection |
| Thickness and preparation | Remove unwanted fat carefully while preserving the required graft layers; neither extreme thinning nor full thickness guarantees take |
| Patient and wound factors | Consider perfusion, smoking, diabetes, nutrition, prior treatment and postoperative wound mechanics |
For skin-graft biology and fixation evidence, see STSG and FTSG. For a poorly vascularized urethral bed, consider the role of vascularized flaps. EAU 2026 recommends a graft over a flap when both are equally indicated and flaps when the urethral bed is poorly vascularized .[10]
BMG ureteroplasty: a graft needs an appropriate vascular environment. Omentum is a commonly used adjunct. The support and wrapping plan depends on the repair and available tissues; see the operative page.[1]
Quick Reference: Grafts in GU Reconstruction
| Tissue | Donor | Principal role / caution |
|---|---|---|
| Buccal mucosa | Inner cheek | Common urethral graft; selected ureteral augmentation |
| Lingual mucosa | Ventrolateral tongue | Oral donor alternative or supplement; different speech/tongue morbidity |
| Oral-lip mucosa | Inner lip | Selected oral donor; not genital labial tissue |
| Rectal mucosa | Rectum, with transanal harvest | Selected complex salvage; limited comparative and long-term evidence |
| Penile / preputial skin | Healthy penile skin / prepuce | Selected graft or flap applications; specify which, assess hair and avoid genital skin in LS-related urethral strictures |
| Postauricular skin | Behind the ear | Selected alternative skin donor when usual tissues are unsuitable |
| STSG | Epidermis plus part of dermis | Genital/perineal coverage and selected vaginal reconstruction |
| FTSG | Epidermis plus full dermis | Selected coverage; donor closure and revascularization demands |
| Bladder mucosa | Bladder | Selected/historical urethral substitute; separate donor morbidity |
| Saphenous vein | Leg | Vascular conduit or prepared patch in selected operations |
| Intestinal segment | Ileum / colon | Usually transferred with its mesenteric blood supply, rather than as a free mucosal graft |
Graft Detail
Buccal Mucosa Graft (BMG)
Buccal mucosa provides hairless, non-keratinizing stratified squamous lining. Oral mucosa is the usual first donor considered when a urethral graft is required and suitable tissue is available . [8][10] In biopsies from 22 men undergoing repeat urethroplasty a mean 22.2 months after graft placement, engrafted buccal mucosa retained squamous histology without urothelial overgrowth.[21]
Assess oral health, previous harvest, mouth opening and the required dimensions. Identify and protect the parotid duct and surrounding structures. Donor closure, bilateral harvest and the choice of buccal versus another oral site require individual planning; the detailed BMG page describes the relevant comparisons.
Uses. Buccal mucosa is placed as a dorsal, ventral or lateral onlay in anterior urethroplasty, as an augmentation in augmented anastomotic repair, and as a graft in selected posterior reconstruction combined with anastomotic repair. It is also used to augment the female urethra.[8] In Zhao's four-patient robotic series for proximal or multifocal ureteral strictures not amenable to primary anastomosis, all four repairs were reported successful at median 15.5 months.[1] A later retrospective multicenter robotic BMG series reported 150/163 (92.0%) free from further intervention for recurrent stenosis at median 29 months; median stricture length was 3.0 cm (IQR 2.0–4.0).[18] A 2026 systematic review found oral mucosal ureteroplasty was most often reported for strictures <5 cm; heterogeneous definitions and short follow-up precluded pooled or long-term estimates.[16]
Harvest. The cheek is retracted with a self-retaining retractor. The parotid (Stensen) duct opening, near the upper second molar, and the oral commissure are identified and avoided. The graft is elevated with scissors, and the donor site may be closed or left open; both are accepted (see the BMG page for the supporting trials).
Limitations. Cheek harvest can cause swelling, numbness and reduced mouth opening. Prior harvest, oral fibrosis, radiation or restricted mouth opening can limit the available graft.[8]
Lingual Mucosa Graft
Lingual mucosa is an alternative or supplemental oral donor. Discuss tongue movement, speech, taste and eating symptoms alongside the different morbidity of cheek harvest. Safe harvest follows the actual ventrolateral anatomy; a choice of surface does not automatically eliminate nerve injury.[10] Lingual mucosa is thinner than buccal mucosa and may suit the distal urethra and meatus. The AUA amendment cites a meta-analysis of 12 studies with no difference in success between buccal and lingual grafts; buccal harvest carried more donor-site swelling, numbness and reduced mouth opening, and lingual harvest more difficulty with speech and tongue protrusion.[8] Lingual mucosa is used when cheek tissue is unavailable, or with buccal mucosa to add length in long strictures. See Lingual Mucosa.
Labial Mucosa Graft
Here labial means oral lip. Inner-lip mucosa is distinct from the vermilion and from female genital labia. Restricted donor territory and possible persistent lip discomfort, numbness, salivary or cosmetic changes affect selection.[10] See Oral-Lip Mucosa; identify the exact donor whenever reading a female-urethroplasty report that uses the word “labial.”
Rectal Mucosa Graft
Rectal mucosa is a selected salvage option when adequate oral tissue is unavailable or unsuitable. It has columnar epithelium and requires assessment of both recipient reconstruction and rectal donor morbidity. In Monn's five-patient TEM series, colorectal assessment and colonoscopy preceded harvest; potential TEM complications include resection-site pain or infection, fecal incontinence, fistula and rectal perforation.[19] One patient had a small urethral diverticulum, which the authors thought related to thin rectal mucosa; they noted the need for adequate tissue support.[19] Transanal endoscopic, robotic and single-port harvests have been described; none is established as universally superior.[3][4][6][7][9]
Indications. Rectal mucosa is used when oral mucosa is unavailable, insufficient or unsuitable, mainly in long-segment and panurethral strictures. In the multi-institutional TURNS series of 13 patients, 9 (69%) had a failed prior buccal graft urethroplasty, 6 (46%) had lichen sclerosus and 3 (23%) had strictures after gender-affirming surgery.[3] Median stricture length was 13 cm and mean graft length was 10.6 cm (range 3 to 16).[3] Repairs were dorsal or ventral onlays or the first stage of a staged repair.[3] The AUA amendment recommends oral mucosa as the first choice .[8] Colonic mucosal grafts for the urethra were first described by Thyrmos in 1902, but early techniques required sigmoid resection.[5]
Harvest approaches. All are transanal, under general anesthesia in lithotomy.
| Approach | Report | Notes |
|---|---|---|
| Transanal endoscopic microsurgery (TEM) | Palmer 2016 (four patients) | Introduced in 2013 as a minimally invasive alternative to sigmoid resection[4] |
| Robotic transanal minimally invasive surgery (R-TAMIS) | Howard 2019 (six urethral strictures and one vaginal stricture) | GelPOINT Path platform with submucosal hydrodissection; mean graft 11.4 × 3.0 cm; flexible sigmoidoscopy confirmed hemostasis[7] |
| Single-port endorobotic | Emrich Accioly 2022 (one case) and Ozgur 2023 (two cases) | da Vinci SP with GelPOINT Path, pneumorectum 12 mmHg; dissection begins about 2 cm proximal to the sphincter complex; one 21 × 3 cm graft[6][9] |
The mucosa is lifted with a submucosal injection, harvested as mucosa alone and thinned before placement. Reported advantages are graft length and avoidance of oral morbidity. All seven rectal-harvest patients in Howard's series regained bowel function on postoperative day one, and those with a prior cheek harvest subjectively reported less pain.[6][7] Limitations are the absence of head-to-head comparisons with oral mucosa, small short-term series, the need for a colorectal surgeon experienced in transanal platforms, and unknown long-term behavior of a columnar epithelium in the urethra.[3][4]
| Report | Actual population and finding | Main limitation |
|---|---|---|
| Granieri 2019 | 13 reconstructions; two recurrences at median follow-up 13.5 months; no bowel-related complication reported [3] | Small heterogeneous salvage cohort; other complications included glans dehiscence, urethrocutaneous fistula and compartment syndrome |
| Palmer 2016 | Four patients; one recurrence; median follow-up 18 months [4] | Ten months was the time of the recurrence, not median follow-up |
| Howard 2019 | Six urethral and one vaginal stricture; favorable graft take and no reported complications at median 17 months [7] | Not seven urethroplasties; subjective pain comparison with prior cheek harvest is not randomized evidence |
| Emrich Accioly 2022 | One patient; a 21 × 3 cm graft and discharge on day two [6] | Technical feasibility |
| Ozgur 2023 | Two cases describing single-port harvest[9] | Small technical report |
| Staged graft take has also been illustrated.[5] |
Product safety: older harvest descriptions used ORISE gel. The FDA Class 2 recall record lists an October 10, 2022 advisory and a December 13, 2022 product-removal update after remnant gel caused mass-forming foreign-body reactions. It should not be recommended as a current lifting agent.[11] Plan contemporary instrumentation and lifting agents with the colorectal team using current product labeling. See Enterourethroplasty for the distinction between a free mucosal graft and vascularized bowel substitution.
Intestinal Segments
Most bowel segments used for augmentation, diversion or intestinal vaginoplasty retain their mesenteric supply. Sigmoid vaginoplasty is not McIndoe skin-graft vaginoplasty. Mucus and absorption are consequences to manage.
| Segment | Properties | Common uses |
|---|---|---|
| Ileum | Compliant, mucus-producing, long mesentery | Augmentation, orthotopic neobladder, ileal conduit |
| Sigmoid colon | Thicker wall, larger caliber | Augmentation, colon conduit, sigmoid vaginoplasty |
| Ileocecal segment | Ileocecal valve, cecal reservoir | Ileocecal augmentation, continent cutaneous diversion |
Reservoir configuration, bowel length and location and urine contact determine risks such as hyperchloremic metabolic acidosis, mucus obstruction, infection, stones and B12 deficiency after terminal ileal use. An augmented bladder also requires long-term surveillance. The ileocecal valve may contribute to a continence mechanism; it is not automatically a ureteral antireflux mechanism. Use the detailed intestinal-segment page, augmentation principles and diversion principles for selection and lifelong follow-up.
Penile / Preputial Skin Graft
A free preputial graft, a pedicled preputial island flap and tubularization of the native urethral plate are different operations. Duckett is a flap technique; standard TIP does not require a free graft. Circumcision limits preputial availability, but it does not remove all penile skin.
Assess healthy donor tissue and actual hair distribution. Do not use genital skin grafts in LS-related urethral strictures , and use penile skin when buccal or lingual mucosa is unavailable, unsuitable or declined . EAU also gives a strong recommendation against tubularized grafts in a single-stage approach; flaps are preferred when a one-stage tube is needed.[10] See Penile / Preputial Skin.
Saphenous Vein Graft
Vein used as a vascular conduit differs from an opened patch used for another reconstructive purpose. The AUA 2018 ED guideline states that penile arterial reconstruction may be considered in young men with focal arterial occlusion and no generalized vascular disease or veno-occlusive dysfunction , and that penile venous surgery is not recommended .[14] See Saphenous Vein for the specific applications and limitations.
Posterior Auricular Skin Graft
Postauricular skin is a selected alternative donor. Available area, thickness, hair, pigmentation and closure vary. See Posterior Auricular Skin.
Skin Grafts (STSG and FTSG)
| Property | STSG | FTSG |
|---|---|---|
| Composition | Epidermis and partial dermis | Epidermis and full dermis |
| Immediate recoil after harvest | Generally less | Generally greater |
| Later contraction during healing | Generally greater | Generally less |
| Donor wound | Re-epithelializes from retained structures | Usually closed primarily |
| Hair | Depends on donor and harvest | Depends on donor and preparation |
| Penile coverage | Established option for selected defects | Established option for selected defects |
Meshed split-thickness grafts (commonly expanded 1:1.5 or 1:2) conform to irregular perineal or scrotal contours after Fournier debridement. For scrotal grafting, prepare a healthy granulating bed before placement.[20] Neither graft has a guaranteed take rate, minimal contraction in every site or proven universal superiority for penile coverage. Donor, recipient bed, dimensions and postoperative support determine suitability. See the full STSG and FTSG discussions.
For vaginal agenesis, supported dilation is first-line for most patients ready for treatment; McIndoe or other surgery follows informed discussion and still requires postoperative dilation.[13] In a McIndoe neovagina, split-thickness skin is grafted over a vaginal mold. Dressing choice at split-thickness donor sites is addressed in a Cochrane review of hydrogel dressings, which included only two randomized trials.[15]
Bladder Mucosa Graft
Bladder mucosa is a urothelial donor with historical and selected contemporary applications. It was used in pediatric hypospadias and complex urethral reconstruction and as a free graft in vesicovaginal fistula repair. See Bladder Mucosa.
Tissue-Engineered Grafts & Bioscaffolds
Cell-free matrices and cell-seeded constructs differ in preparation, regulation, recipient-bed requirements and evidence. See Tissue-Engineered Grafts & Bioscaffolds and the relevant guideline restrictions. EAU 2026 recommends against cell-free engineered grafts in extensive spongiofibrosis, after failed urethroplasty or for strictures longer than 4 cm , and against autologous tissue-engineered oral mucosa outside a clinical trial .[10]
Graft Selection Summary
Start with the defect and viable recipient tissue, then compare suitable donors and the morbidity of each. Separate graft versus flap, patch versus tube, skin versus mucosa, and early graft incorporation versus durable function.
| Scenario | Commonly used tissue | Comment |
|---|---|---|
| Anterior urethral stricture | Oral mucosa, usually buccal | AUA 2023 Expert Opinion: oral mucosa is the first choice for grafts[8] |
| Long stricture with limited cheek tissue | Bilateral buccal, or buccal with lingual mucosa | Buccal and lingual mucosa are equivalent alternatives [8] |
| Oral mucosa unavailable or exhausted, very long stricture | Penile skin if suitable; rectal mucosa for selected complex salvage | EAU 2026 weakly recommends penile skin when oral mucosa is unavailable, unsuitable or declined; rectal-graft evidence remains small series.[10][3] |
| Female urethral stricture | Oral mucosa graft or vaginal flap | AUA 2023 favors urethroplasty over endoscopic treatment[8] |
| Selected ureteral stricture | Oral mucosal onlay with a viable recipient bed; vascularized support when indicated[1] | A 2026 review found buccal and lingual grafts most often used for strictures <5 cm; studies were mostly retrospective with heterogeneous outcomes and short follow-up.[16] |
| Scrotal or perineal resurfacing | Meshed STSG | Conforms to irregular contours |
| Penile shaft coverage | STSG or FTSG | FTSG contracts less; donor closure and take differ |
| Bladder augmentation | Ileum | Vascularized segment, not a free graft |
| Pediatric hypospadias | Preputial tissue or buccal-mucosa inlay in selected primary repairs; oral graft in selected staged repairs | TIP tubularizes the native urethral plate after any inlay; complex defects may require staged reconstruction.[17] |
Start with the defect and viable recipient tissue, then use the linked donor pages and named-operation guidance for patient-specific selection.
References
1. 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. PMID 26123519
2. Converse JM, Smahel J, Ballantyne DL Jr, Harper AD. Inosculation of vessels of skin graft and host bed: a fortuitous encounter. Br J Plast Surg. 1975;28(4):274–282. doi:10.1016/0007-1226(75)90031-4. PMID 1104028
3. Granieri MA, Zhao LC, Breyer BN, et al. Multi-institutional outcomes of minimally invasive harvest of rectal mucosa graft for anterior urethral reconstruction. J Urol. 2019;201(6):1164-1170. doi:10.1097/JU.0000000000000087.
4. Palmer DA, Marcello PW, Zinman LN, Vanni AJ. Urethral reconstruction with rectal mucosa graft onlay: a novel, minimally invasive technique. J Urol. 2016;196(3):782-786. doi:10.1016/j.juro.2016.03.002.
5. Pagura EJ, Cavallo JA, Zinman LN, Vanni AJ. Rectal mucosa graft take in staged urethroplasty. Urology. 2019;127:e1-e2. doi:10.1016/j.urology.2019.02.023.
6. Emrich Accioly JP, Zhao H, Ozgur I, et al. Single-port, robot-assisted transanal harvest of rectal mucosa grafts for substitution urethroplasty. Urology. 2022;166:1-5. doi:10.1016/j.urology.2022.04.018.
7. Howard KN, Zhao LC, Weinberg AC, et al. Robotic transanal minimally invasive rectal mucosa harvest. Surg Endosc. 2019;33(10):3478-3483. doi:10.1007/s00464-019-06893-w.
8. Wessells H, Morey A, Souter L, Rahimi L, Vanni A. Urethral stricture disease guideline amendment (2023). J Urol. 2023;210(1):64-71. doi:10.1097/JU.0000000000003482.
9. Ozgur I, Justiniano CF, Wood HM, Gorgun E. Single-port endorobotic rectal mucosa harvest for urethral reconstruction. Dis Colon Rectum. 2023;66(2):e54-e57. doi:10.1097/DCR.0000000000002577.
10. European Association of Urology. Urethral Strictures Guidelines: Tissue Transfer. 2026. Guideline chapter.
11. US Food and Drug Administration. Class 2 Device Recall: Boston Scientific ORISE Gel Submucosal Lifting Agent. Recall initiated October 10, 2022. Recall record.
12. Converse JM, Uhlschmid GK, Ballantyne DL Jr. “Plasmatic circulation” in skin grafts: the phase of serum imbibition. Plast Reconstr Surg. 1969;43(5):495–499. doi:10.1097/00006534-196905000-00007. PMID 4889411.
13. ACOG Committee on Adolescent Health Care. Committee Opinion No. 728: Müllerian agenesis: diagnosis, management, and treatment. Obstet Gynecol. 2018;131:e35–e42. doi:10.1097/AOG.0000000000002458.
14. Burnett AL, Nehra A, Breau RH, et al. Erectile dysfunction: AUA guideline. J Urol. 2018;200:633–641. doi:10.1016/j.juro.2018.05.004. Guideline.
15. Younis AS, Abdelmonem IM, Gadullah M, et al. Hydrogel dressings for donor sites of split-thickness skin grafts. Cochrane Database Syst Rev. 2023;8:CD013570. doi:10.1002/14651858.CD013570.pub2.
16. Ditonno F, Costantino S, Treccani LP, et al. "Autologous tissue substitutes for ureteral reconstruction: A systematic review of surgical techniques and outcomes." Eur Urol Open Sci. 2026;86:30-41. doi:10.1016/j.euros.2026.02.007
17. European Association of Urology. "EAU Guidelines on Paediatric Urology: Hypospadias." EAU Guidelines. 2026. Guideline chapter.
18. 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
19. Monn MF, Waters JA, Mellon MJ. "Use of rectal mucosal grafts in substitution urethroplasty: an early series." Transl Androl Urol. 2018;7(6):907-911. doi:10.21037/tau.2018.10.12
20. Karian LS, Chung SY, Lee ES. "Reconstruction of Defects After Fournier Gangrene: A Systematic Review." Eplasty. 2015;15:e18. PMID 26171090
21. Soave A, Steurer S, Dahlem R, et al. "Histopathological characteristics of buccal mucosa transplants in humans after engraftment to the urethra: a prospective study." J Urol. 2014;192(6):1725-1729. doi:10.1016/j.juro.2014.06.089