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. It is not a universally superior flap, and abdominal harvest has meaningful potential complications.[1][3][21]
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. These properties provide a rationale for reconstruction; they do not guarantee infection clearance, graft survival or prevention of fibrosis. A flap complements debridement, drainage and sound repair—it does not replace them.[1][2][21]
Omentum is soft and conforms to a defect, but it has no native skin paddle and provides little structural strength. Its volume varies considerably. Do not describe it as a porous drain for urine or blood, or assume that removing or transposing it has no consequences. Clinical benefits differ by operation.[21][23][24]
Anatomy and Pedicle Planning
The greater omentum extends from the greater curvature of the stomach and attaches to the transverse colon/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. Omental branches and their communicating arcades vary; an intact, functionally adequate connection should not be assumed in every patient.[3][4][26]
Topor's study of 45 cadavers and operative observations in 20 patients described three principal omental arterial patterns. The middle omental artery was absent in one pattern, while another depended on smaller communicating vessels. This variation matters when dividing or lengthening the flap; the named vascular pattern is not a substitute for assessing the tissue in front of the surgeon.[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.[26]
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][21]
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/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. A particular vessel sealer is not mandatory, and 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][21]
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. A specific robot does not guarantee access from every pelvic setup.
Zaha's 96-patient laparoscopic series involved immediate breast reconstruction, not GU surgery. Harvest succeeded in 95/96; eight patients had laparoscopy-associated complications, including one incisional hernia. Without a concurrent open control, this does not establish a particular reduction in morbidity compared with open harvest.[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. A flap cannot make a nonviable or tensioned closure reliable.[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. A technique demonstration, not an established same-day discharge or long-term cure rate.[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; this is not nine identical omental repairs.[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. Adjusted recurrence results favored omentum over primary repair, but did not establish superiority over VRAM.[20] |
For urosymphyseal fistula, source control may require pubic-bone debridement, urinary reconstruction or cystectomy/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.[20]
The 2026 Cochrane VVF publication is a review protocol, with no completed comparative results. It cannot establish routine interposition or a preferred flap.[6] 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, but it is not the only acceptable tissue. The 2026 European multicenter report used omentum in most cases and peritoneal or perinephric fat alternatives in others. Its 39 patients had 87% overall success at median 12-month follow-up; the study did not compare flap types or prove that the omental wrap caused success.[25]
Onlay and augmented-anastomotic graft repairs preserve or reconstruct a ureteral plate. They should not be equated with a completely tubularized free graft. Choose coverage that is viable and reaches without compression; reported whole-procedure success rates are not measurements of the wrap's independent benefit.[25]
Ureterolysis for retroperitoneal fibrosis
Ureterolysis relieves encasement; intraperitonealization and tissue interposition can separate the ureter from the fibrotic bed. Omental wrapping is an option, not a guarantee against recurrent encasement or a replacement for assessment and treatment of the underlying disease. 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. These small series support feasibility rather than 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 complex/previously failed pelvic-fracture defects. Fourteen avoided subsequent instrumentation at median 18 months. It describes a specialist adjunct; without a control group, the effect of omentum cannot be separated from the urethroplasty.[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/fasciocutaneous reconstruction. The defect and planned perineal closure determine whether omentum is useful alone, as an adjunct or not at all.[23]
| Evidence | Interpretation |
|---|---|
| Blok 2020 systematic review, 14 studies / 1,894 patients after APR for cancer | 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). Allocation was not randomized; definitions and follow-up varied. Does not support routine omentoplasty after APR.[23] |
| Peng 2024 broader systematic review | The heterogeneous pelviperineal studies did not show a consistent overall benefit. Results from esophageal, gastric or hepatic operations should not be transferred to GU reconstruction; exploratory age/BMI subgroups do not establish treatment cutoffs.[24] |
| 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.[18] |
| Miyamoto 2016, 27 exenteration patients | Only 10 received omentum, versus 17 without. Fewer pelvic infections were reported with omentum; small, selected retrospective groups.[16] |
| Hultman 2010, 70 APR/exenteration patients | Major pelvic complications occurred in 6/29 with omentum versus 25/41 without. Groups included different primary and muscle-flap reconstructions; this does not isolate the benefit of omentum.[17] |
Campbell's retrospective analysis of 185 VRAM reconstructions associated adjunctive omentum with less minor perineal dehiscence. Several technical modifications were examined, so the result supports selective consideration rather than proven synergy or routine combined flaps.[19]
Other Specialist and Historical Applications
- Neovaginal reconstruction after exenteration: an omental cylinder or J-flap can support a split-thickness skin graft. Kusiak's 20-patient series reported viable flaps/grafts and potential for sexual function in approximately 80%; this was not a validated 80% sexual-function outcome or a comparative trial. Selection, a suitable graft bed and postoperative maintenance matter.[14][15]
- Bladder-neck reconstruction: Diamond's 1986 report combined omentum, silicone wrapping and, in some patients, augmentation. Continence cannot be attributed to omentum alone, and silicone erosion was a substantial complication. This is historical evidence, not a contemporary wrap protocol.[12]
- Tissue-engineered bladder: Atala's seven-patient study varied scaffold composition and omental coverage together. It does not isolate an omental treatment effect or establish an alternative standard to conventional augmentation. See augmentation principles for the broader context.[13]
- Irradiated wounds: viable omentum may bring vascularized tissue into a compromised field, but cannot be assumed to reverse radiation injury or guarantee protection from future radiation enteritis.[2][21]
Donor Risk and Counseling
Hultman's 135-patient series concerned extraperitoneal reconstruction, predominantly head/neck and thoracic wounds, with only seven perineal cases. Almost all harvests used laparotomy. It establishes that meaningful donor morbidity occurs, but does not estimate the exact risk of a modern robotic GU operation.[21]
| 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 |
| Prolonged 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/flap outcomes, not additional abdominal donor-site categories. Eight patients died overall; the authors reported no deaths directly attributable to harvest or donor morbidity. Do not present the 5.9% overall mortality as an omental-harvest mortality rate.[21]
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. For selected cases, a perivesical fat flap is an alternative described in a small technical series, not a proven equivalent to omentum.[21][22]
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 |
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. Wheeless CR. "Neovagina Constructed From an Omental J Flap and a Split Thickness Skin Graft." Gynecol Oncol. 1989;35(2):224–226. doi:10.1016/0090-8258(89)90048-6
16. 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
17. 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
18. 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
19. 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
20. 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
21. 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
22. 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
23. 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.
24. 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.
25. 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.
26. 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.