Omental Flap
The greater omentum is a useful vascularized flap for selected fistula repairs, graft coverage and pelvic reconstruction. Its pliability, variable volume and vascular supply can help separate repairs or fill an irregular defect. Availability, perfusion, reach and the actual tissue requirement determine whether it is appropriate.[1][3][20] Abdominal harvest has meaningful potential complications.[1][3][20]
See Flaps in GU Reconstruction, Peritoneal Flap, VRAM, Gracilis and Martius.
Tissue Properties
The omentum contains vessels, lymphatics and immune-cell aggregates, and experimental work supports angiogenic and immunologic activity. Turner-Warwick described the omentum as the only body tissue specifically developed for the resolution of infected processes and noted that it regains its suppleness after healing, unlike periureteral and perivesical tissue.[1] Logmans, reviewing gynecologic use (48 omentoplasties), described its rich vascularity and thromboplastin content, a trophic effect on surrounding tissue, use as a matrix for grafting, and elevation of small bowel out of the pelvis before high-dose brachytherapy to reduce radiation enteritis.[2] A flap complements debridement, drainage and sound repair and does not replace them.[1][2][20]
Omentum is soft and conforms to a defect, but it has no native skin paddle and provides little structural strength. Its volume varies considerably. Clinical benefits differ by operation.[20][22][23]
Anatomy and Pedicle Planning
The greater omentum extends from the greater curvature of the stomach and attaches to the transverse colon and mesocolon. Its main vascular supply comes from the right gastroepiploic artery, arising from the gastroduodenal artery, and the left gastroepiploic artery, arising from the splenic artery.[3][4][25] Omental branches and their communicating arcades vary.[3][4][25]
Topor's study of 45 cadavers and operative observations in 20 patients described three principal omental arterial patterns: one right, one or two middle and one left omental artery (56%); absent middle omental artery (26%); and a gastroepiploic artery continuing as a left omental artery with smaller connections to the right or middle omental artery (18%). Topor described omental lengthening in stages: detachment from the transverse colon mesentery (the omentum adheres closely to the right transverse mesocolon), lengthening of the omentum itself, then placement into the pelvis.[3]
Gastric branches of the gastroepiploic vessels are distinct from the short gastric vessels in the gastrosplenic ligament. Describing every vessel between the gastroepiploic arcade and stomach as a “short gastric artery” is anatomically misleading. Gastric, splenic, mesocolic and pedicle injury are possible during mobilization.[25]
A flap may retain both pedicles or be based on one, depending on the required arc of rotation and the vascular anatomy. Further lengthening can use preserved collateral arcades, including the marginal arcade described by Barkow. Neither side guarantees pelvic reach. Prior operations, adhesions, damaged vessels and insufficient volume can make harvest unsuitable. Do not divide a pedicle merely because pelvic reconstruction is planned.[3][4][20]
Harvest and Inset Principles
- Define the reconstructive need and an alternative. Determine whether the defect needs thin interposition, vascularized graft coverage, substantial bulk, skin or structural pelvic-floor reconstruction.
- Inspect the omentum and its vascular attachments. Assess the effect of prior surgery, adhesions and existing vascular injury before committing to a flap.
- Release only what is needed for safe reach. Detachment from the transverse colon and mesocolon may be sufficient; further mobilization from the stomach or lengthening requires preservation of the intended inflow and venous drainage. Avoid traction injury to bowel, stomach and spleen.
- Control divided vessels under direct vision. Clips, ligatures or an appropriate energy device may be used. Thermal spread near the retained pedicle or viscera must be considered.
- Check the route and perfusion before inset. Deliver without tension, twisting, compression or an aperture that could entrap bowel. A tunnel or mesenteric window must protect the structures it traverses.
- Inset gently and reassess. Avoid a constricting wrap around a ureter or repair. Secure the tissue as needed while preserving its pedicle, then check abdominal closure, hemostasis and the remaining potential spaces.[3][4][20]
Open, laparoscopic and robotic harvest are possible. Port placement, patient position, access to the upper abdomen and the need for repositioning or redocking depend on the operation and platform.
Zaha's 96-patient laparoscopic series involved immediate breast reconstruction, not GU surgery. Harvest succeeded in 95/96 without conversion (median operative time about 1 hour), and graft survival was 96.8% (93/95), with partial necrosis in 5.2% and gastroepiploic vascular injury in 2.1%. Eight patients (8.3%) had laparoscopy-associated complications, including one incisional hernia.[5]
Fistula Interposition
Omentum can separate closed urinary and adjacent visceral structures during an abdominal repair, particularly when additional viable tissue is needed after previous surgery or radiation. Fistula location, exposure, tissue quality and the complete repair determine the choice. Local vaginal flaps, Martius, peritoneum, gracilis or other options may be more appropriate in other approaches.[1][6]
| Report | What it supports |
|---|---|
| Watts 2017, robotic extravesical VVF | One patient was discharged on postoperative day 1 and reported no incontinence at three months.[7] |
| Trippitelli 1985, rectourethral fistula | Nine patients had good reported outcomes after varied repairs. Eight had an abdominoperineal approach with omentum or peritoneum, and one had a perineal approach.[8] |
| Escandón 2026, urosymphyseal fistula | Retrospective series of 56: 34 omentum, 11 VRAM and 11 primary repairs. Reported 90-day sepsis was 3%, 27% and 18%, respectively. At 90 days, omental repair was associated with lower adjusted odds of fistula recurrence than primary repair, but no significant advantage over VRAM was shown; longer-term benefit remains uncertain.[19] |
For urosymphyseal fistula, source control may require pubic-bone debridement, urinary reconstruction or cystectomy or diversion according to the damaged tissues and urinary function. Escandón included selected patients undergoing anterior exenteration. Small groups, treatment selection and differing reconstructive needs prevent a universal flap ranking or a causal interpretation of the sepsis percentages.[19]
The 2026 Cochrane VVF publication is a review protocol, with no completed comparative results.[6] A 2024 review of 46 studies found no statistically significant improvement in fistula cure in the assessed interpositional-flap comparisons.[26] In a randomized trial of simple transabdominal VVF (≤4 cm and at most two fistulous openings), repair without vaginal urine leakage occurred in 34/35 patients with omental interposition and 33/34 without a flap (p = 1.0); mean follow-up was 39.6 months across all 126 trial participants.[27] Prior failed repairs, post-radiation fistulas, and malignancy-related fistulas were excluded, and the trial was too small to establish equivalence.[27] See the VVF pathway for the wider repair framework.
Ureteral and Urethral Reconstruction
Buccal mucosa graft ureteroplasty
A free buccal graft depends on its recipient bed for incorporation. Omentum is a commonly used vascularized cover. The 2026 European multicenter report used omentum in most cases and peritoneal or perinephric fat alternatives in others.[24] Its 39 patients had 87% overall success at median 12-month follow-up.[24] The study did not compare flap types.[24]
Onlay and augmented-anastomotic graft repairs preserve or reconstruct a ureteral plate. A completely tubularized free graft lacks that ureteral plate and is a different reconstructive construct.[24] Choose coverage that is viable and reaches without compression.[24]
Ureterolysis for retroperitoneal fibrosis
Ureterolysis relieves encasement; intraperitonealization and tissue interposition can separate the ureter from the fibrotic bed. Bilateral reconstruction must be planned around available tissue and vessels; division into two flaps is not obligatory.[9][10]
Fong's report described three patients and used both omental and peritoneal options, including different tissues for the two sides of a bilateral repair. Stein reported four patients, all with symptomatic/radiographic success at median 16.5 months; one required reoperation for hand-port fascial dehiscence.[10] These small series support feasibility without establishing a general 100% durable success rate.[9][10]
Complex posterior urethroplasty
Kulkarni's prospective stage-2a series combined elaborate perineal anastomotic repair with laparoscopic omentoplasty in 15 males (seven adolescents and eight adults) with complex or previously failed pelvic-fracture defects. Fourteen avoided subsequent instrumentation at median 18 months.[11]
Pelvic Dead Space and Pelvic-Floor Defects
Filling the presacral space and reconstructing the pelvic floor are different goals. Loose omental fat does not reproduce the strength or skin coverage of a musculocutaneous or fasciocutaneous reconstruction.[22]
| Evidence | Interpretation |
|---|---|
| Blok 2020 systematic review, 14 studies / 1,894 patients after abdominoperineal cancer resections (mostly APR) | No significant improvement in presacral abscess (RR 1.11, 95% CI 0.79–1.56) or complicated healing within 30 days (RR 1.30, 0.92–1.82). Perineal hernia was more frequent with omentoplasty (RR 1.85, 1.26–2.72); omentoplasty-related complications were reported in 4.6% across eight reporting studies. Allocation was not randomized; definitions and follow-up varied.[22] |
| Peng 2024 broader systematic review | The heterogeneous pelviperineal studies showed no consistent overall benefit.[23] |
| Welten 2019 NSQIP, 3,063 APR patients | Omentum was used in 173. Organ-space infection was 10.4% versus 6.5%; adjusted OR 1.72 (95% CI 1.02–2.90). Observational association, with residual selection/confounding possible.[17] |
| Miyamoto 2016, 27 exenteration patients | Only 10 received omentum, versus 17 without. Fewer pelvic infections were reported with omentum; small, selected retrospective groups.[15] |
| Hultman 2010, 70 APR/exenteration patients | Major pelvic complications (abscess, urinoma, thrombosis, flap dehiscence, hernia, obstruction, fistula) occurred in 6/29 (21%) with omentum versus 25/41 (61%) without (p < 0.01). Groups included different primary and muscle-flap reconstructions.[16] |
Campbell's retrospective analysis of 185 VRAM reconstructions associated adjunctive omentum with less minor recipient-site dehiscence (11.1% versus 32.5%, p < 0.05); omentum plus VRAM was protective against perineal skin dehiscence on multivariable analysis, and higher BMI was predictive of it. Several technical modifications were examined, so the result supports selective consideration without proving synergy or justifying routine combined flaps.[18]
Other Specialist and Historical Applications
- Neovaginal reconstruction after exenteration: an omental cylinder or J-flap can support a split-thickness skin graft.[14] Kusiak's 20-patient series after exenteration reported viable flaps and grafts with no pelvic infection, perineal fistula or hernia, and potential for sexual function in approximately 80%.[14]
- Bladder-neck reconstruction: Diamond's 1986 report of 39 patients wrapped a Young-Dees tube with omentum and silicone, with simultaneous augmentation in 43%. Among exstrophy patients, 85% of those who had augmentation and 15% of those who did not were dry, and silicone erosion occurred in all five initial patients with a thick silicone wrap and in 14% of those with a thin wrap.[12]
- Tissue-engineered bladder: Atala's seven-patient study in children and adolescents with myelomeningocele varied scaffold composition and omental coverage together. In the seven-patient study, the greatest reported changes were in composite constructs with an omental wrap: mean bladder leak-point pressure at capacity decreased by 56%, while volume increased 1.58-fold and compliance increased 2.79-fold (follow-up 22–61 months). See augmentation principles for the broader context.[13]
- Irradiated wounds: viable omentum may bring vascularized tissue into a compromised field.[2][20]
Donor Risk and Counseling
Hultman's 135-patient series concerned extraperitoneal reconstruction, predominantly wounds of the head and neck or thorax, with only seven perineal cases. Almost all harvests used laparotomy. Of the 135 flaps, 64 were pedicled and 71 free; pedicled flaps, mediastinitis, advanced age and pulmonary failure were associated with more donor-site complications, and 26 of 53 patients with prior abdominal surgery needed extensive adhesiolysis (4 enterotomies).[20]
| Donor event | Reported patients |
|---|---|
| Any donor-site complication | 25/135 (18.5%) |
| Abdominal-wall infection | 9/135 |
| Fascial dehiscence | 8/135 |
| Symptomatic hernia | 8/135 |
| Unplanned re-exploration | 6/135 |
| Postoperative ileus | 3/135 |
Less common events included gastrointestinal bleeding, gastric outlet obstruction, delayed splenic rupture and late small-bowel obstruction. Partial and total flap loss were recipient or flap outcomes, not additional abdominal donor-site categories. Eight patients died overall (5.9%).[20]
Previous surgery does not automatically preclude use, but adhesiolysis and enterotomy are relevant risks. An unavailable, poorly perfused or inadequately long flap should prompt a different reconstruction.[20][21] For selected cases, a perivesical fat flap is an alternative described in a small technical series.[20][21]
Practical Selection
| Reconstructive requirement | Decision |
|---|---|
| Abdominally accessible fistula needing interposition | Consider viable, tension-free omentum alongside other appropriate tissues |
| Vascularized cover for BMG ureteroplasty | Omentum is common; perinephric fat or other viable local tissue may be suitable |
| Large perineal defect requiring skin or structural support | Plan the appropriate flap/pelvic-floor reconstruction; omentum may be an adjunct |
| Routine prophylactic filling after APR | Comparative evidence does not support universal use |
| Omentum scarred, absent, ischemic or unable to reach | Select an alternative based on access, defect and donor risk |
Videos
References
1. Turner-Warwick R. "The Use of the Omental Pedicle Graft in Urinary Tract Reconstruction." J Urol. 1976;116(3):341–347. doi:10.1016/s0022-5347(17)58809-6
2. Logmans A, Trimbos JB, van Lent M. "The Omentoplasty: A Neglected Ally in Gynecologic Surgery." Eur J Obstet Gynecol Reprod Biol. 1995;58(2):167–171. doi:10.1016/0028-2243(94)01994-0
3. Topor B, Acland RD, Kolodko V, Galandiuk S. "Omental Transposition for Low Pelvic Anastomoses." Am J Surg. 2001;182(5):460–464. doi:10.1016/s0002-9610(01)00764-4
4. Fix RJ, Vasconez LO. "Use of the Omentum in Chest-Wall Reconstruction." Surg Clin North Am. 1989;69(5):1029–1046. doi:10.1016/s0039-6109(16)44936-4
5. Zaha H, Inamine S. "Laparoscopically Harvested Omental Flap: Results for 96 Patients." Surg Endosc. 2010;24(1):103–107. doi:10.1007/s00464-009-0533-0
6. Okada Y, Matsushita T, Hasegawa T, et al. "Surgical Interventions for Treating Vesicovaginal Fistula in Women." Review protocol. Cochrane Database Syst Rev. 2026;1:CD015413. doi:10.1002/14651858.CD015413
7. Watts KL, Ho R, Ghavamian R, Abraham N. "Robot-Assisted Extravesical Vesicovaginal Fistula Repair Utilizing Laparoscopically Mobilized Omental Flap Interposition." Int Urogynecol J. 2017;28(4):641–644. doi:10.1007/s00192-016-3218-y
8. Trippitelli A, Barbagli G, Lenzi R, Fiorelli C, Masini GC. "Surgical Treatment of Rectourethral Fistulae." Eur Urol. 1985;11(6):388–391. doi:10.1159/000472547
9. Fong BC, Porter JR. "Laparoscopic Ureterolysis: Technical Alternatives." J Endourol. 2006;20(10):820–822. doi:10.1089/end.2006.20.820
10. Stein RJ, Patel NS, Quinn K, et al. "Laparoscopic Ureterolysis With Omental Wrap for Idiopathic Retroperitoneal Fibrosis." BJU Int. 2010;106(5):703–707. doi:10.1111/j.1464-410X.2009.09186.x
11. Kulkarni SB, Barbagli G, Joshi PM, et al. "Laparoscopic Omentoplasty to Support Anastomotic Urethroplasty in Complex and Redo Pelvic Fracture Urethral Defects." Urology. 2015;85(5):1200–1205. doi:10.1016/j.urology.2014.12.055
12. Diamond DA, Ransley PG. "Bladder Neck Reconstruction With Omentum, Silicone and Augmentation Cystoplasty — a Preliminary Report." J Urol. 1986;136(1 Pt 2):252–255. doi:10.1016/s0022-5347(17)44831-2
13. Atala A, Bauer SB, Soker S, Yoo JJ, Retik AB. "Tissue-Engineered Autologous Bladders for Patients Needing Cystoplasty." Lancet. 2006;367(9518):1241–1246. doi:10.1016/S0140-6736(06)68438-9
14. Kusiak JF, Rosenblum NG. "Neovaginal Reconstruction After Exenteration Using an Omental Flap and Split-Thickness Skin Graft." Plast Reconstr Surg. 1996;97(4):775–781; discussion 782–783. doi:10.1097/00006534-199604000-00013
15. Miyamoto Y, Akiyama T, Sakamoto Y, et al. "Omental Flap After Pelvic Exenteration for Pelvic Cancer." Surg Today. 2016;46(12):1471–1475. doi:10.1007/s00595-016-1348-y
16. Hultman CS, Sherrill MA, Halvorson EG, et al. "Utility of the Omentum in Pelvic Floor Reconstruction Following Resection of Anorectal Malignancy: Patient Selection, Technical Caveats, and Clinical Outcomes." Ann Plast Surg. 2010;64(5):559–562. doi:10.1097/SAP.0b013e3181ce3947
17. Welten VM, Fields AC, Lu P, et al. "Omental Flaps in Patients Undergoing Abdominoperineal Resection for Rectal Cancer." Int J Colorectal Dis. 2019;34(7):1227–1232. doi:10.1007/s00384-019-03319-w
18. Campbell CA, Butler CE. "Use of Adjuvant Techniques Improves Surgical Outcomes of Complex Vertical Rectus Abdominis Myocutaneous Flap Reconstructions of Pelvic Cancer Defects." Plast Reconstr Surg. 2011;128(2):447–458. doi:10.1097/PRS.0b013e31821e6fd2
19. Escandón JM, Kreutz-Rodrigues L, Fadel AE, et al. "Optimizing Flap Selection for Urosymphyseal Fistula Repair: A Comparative Analysis of Surgical Outcomes." Microsurgery. 2026;46(3):e70197. doi:10.1002/micr.70197
20. Hultman CS, Carlson GW, Losken A, et al. "Utility of the Omentum in the Reconstruction of Complex Extraperitoneal Wounds and Defects: Donor-Site Complications in 135 Patients From 1975 to 2000." Ann Surg. 2002;235(6):782–795. doi:10.1097/00000658-200206000-00005
21. Hwang A, Watson M, Talluri S, Okafor H, Singh A. "A Novel Perivesical Fat Rotational Flap as an Alternative to Omental Interposition in Challenging Urological Reconstruction." Urology. 2023;182:e262–e263. doi:10.1016/j.urology.2023.08.023
22. Blok RD, Hagemans JAW, Klaver CEL, et al. A systematic review and meta-analysis on omentoplasty for the management of abdominoperineal defects in patients treated for cancer. Ann Surg. 2020;271:654–662. doi:10.1097/SLA.0000000000003266.
23. Peng Y, Xiong S, Ding Y, et al. The effect of omentoplasty in various surgical operations: systematic review and meta-analysis. Int J Surg. 2024;110:3778–3794. doi:10.1097/JS9.0000000000001240.
24. 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.
25. Brenkman HJF, van der Wielen NI, Ruurda JP, et al. Surgical anatomy of the omental bursa and the stomach based on a minimally invasive approach: different approaches and technical steps to resection and lymphadenectomy. J Thorac Dis. 2017;9(Suppl 8):S809–S816. doi:10.21037/jtd.2017.07.52.
26. Thompson JC, Halder GE, Jeppson PC, et al. "Repair of Vesicovaginal Fistulae: A Systematic Review." Obstet Gynecol. 2024;143(2):229–241. doi:10.1097/AOG.0000000000005468
27. Singh V, Mehrotra S, Bansal A, Akhtar A, Sinha RJ. "Prospective randomized comparison of repairing vesicovaginal fistula with or without the interposition flap: Result from a tertiary care Institute in Northern India." Turk J Urol. 2019;45(5):377–383. doi:10.5152/tud.2019.85233