Ideas and Innovations

Use of the Omentum Flap as Additional Soft-Tissue Cover for Abdominal Wall DefectsReconstructed with Gore-TexChin-Ho Wong, M.R.C.S., Bien-Keem Tan, F.R.C.S., Heng-Nung Koong, F.R.C.S.,Chong-Hee Lim, F.R.C.S., Sing-Joo Chia, F.R.C.S., and Colin Song, F.R.C.S.Singapore

Background: Use of alloplastic materialssuch as Gore-Tex and locoregional flaps forreconstruction of large abdominal wall de-fects has been well described. The purposeof this article is to present a novel tech-nique of using the omentum as an inter-positional flap to protect the Gore-Tex re-pair of the abdominal wall.Methods: Four patients with large abdom-inal wall defects underwent reconstructionwith Gore-Tex and omentum flap. Thesedefects resulted from tumor resection andrecurrent incisional hernia. Their dimen-sions ranged from 15 � 10 cm to 25 � 27cm. The Gore-Tex patch was inset using anunderlay technique. The omentum wastunneled through a separate opening inthe abdominal wall into the subcutaneousplane and used to cover the Gore-Tex. Skincoverage was accomplished by direct clo-sure or myocutaneous flaps.Results: The mean follow-up was 17 months.All wounds healed, with no hernias. One pa-tient developed a subcutaneous abscess 6months postoperatively, and this was treatedsuccessfully by percutaneous drainage, as theomentum had walled-off the abscess.Conclusion: The omentum flap served as anadditional soft-tissue cover over the Gore-Texrepair to prevent exposure in the event of

infection or flap breakdown. This techniqueis useful in situations in which delayed woundhealing is anticipated or when large quanti-ties of prosthetic material are used. (Plast.Reconstr. Surg. 116: 1715, 2005.)

The reconstruction of large, full-thicknessabdominal wall defects is often a challengingundertaking. The lack of suitable musculofas-cial tissue in the proximity of the defect has ledto the use of synthetic materials such as Gore-Tex (expanded polytetrafluoroethylene)(W. L. Gore and Associates, Flagstaff, Ariz.).However, complications such as seroma forma-tion, infection, and extrusion are associatedwith the use of prosthetic materials. Such risksmay be increased in situations where skin isdeficient and when closure has to be achievedwith wide skin undermining or flaps. To avoidsuch problems, adequate well-vascularized soft-tissue coverage of the alloplastic material isvital.1,2 The purpose of this article is to presentour approach of using a combination of Gore-Tex and the omentum as an interpositionalflap. This combination is used in addition tolocoregional flaps needed for skin coverage.This additional, well-vascularized soft tissue fa-cilitates wound healing and serves to protectthe implant in the event of cutaneous wound/flap breakdown.

From the Department of Plastic Surgery and the Department of Cardiothoracic Surgery, Singapore General Hospital, the Department ofSurgical Oncology, National Cancer Center, and the Department of General Surgery, Tan Tock Seng Hospital. Received for publication October6, 2004; revised August 28, 2005.

Presented at the 21st Annual Meeting of the American Society for Reconstructive Microsurgery, in Fajardo, Puerto Rico, January 15 through18, 2005.

DOI: 10.1097/01.prs.0000185664.33079.5d

1715

PATIENTS AND METHODS

Between January of 2002 and August of2003, four patients (two men and two women)with large defects of the abdominal wall under-went reconstruction with Gore-Tex DualMesh(W. L. Gore and Associates, Inc.), and omen-tum flap. Defect size ranged from 15 � 20 cm(300 cm2) to 25 � 27 cm (675 cm2). Abdomi-nal wall reconstruction was performed aftertumor resection in three patients. In one pa-tient, it was performed for repair of recurrentincisional hernia. Two patients had overlyingskin defects that were closed with an anterolat-eral thigh myocutaneous flap and a verticalrectus abdominis myocutaneous flap.

Surgical Technique

Surgery is performed by a team consisting ofgeneral and plastic surgeons. The primarypathologic conditions are addressed as follows:for tumor cases, the tumor is widely resectedand completeness of clearance ascertained byfrozen sections. In the sole case of recurrentincisional hernia, all attenuated tissues are ex-cised, leaving behind healthy fascial margins,onto which the Gore-Tex patch is secured. Theabdominal cavity is entered and any bowel thatis adherent to the parietal peritoneum alongthe fascial margin is freed to create space forthe underlying portion of the Gore-Tex. Thegreater omentum is evaluated with regard to itssize, vascular pattern, and reach for a givendefect. Only that which is needed is mobilized.For smaller lateral defects, mobilization fromthe transverse colon would suffice. The omen-tum is passed through a 4-cm slit in the linearsemilunaris into the subcutaneous plane. Theslit opens like a venetian blind and its overlap-ping layers of muscle reduce the risk of herniaformation (Figs. 1 and 2). If the defect is large,the omentum is mobilized fully and pedical-ized on either the right or left gastroepiploicvessels. The exit point is subcostal, located onthe side ipsilateral to the defect. The rightsubcostal site is preferred, as the liver protectsagainst herniation of bowel (Fig. 1).

The Gore-Tex patch is applied using an un-derlay technique described by McCarthy andTweist.3 A 1-mm-thick Gore-Tex sheet istrimmed to size with the aid of a paper cut-outof the defect. An allowance of 3 cm circumfer-entially is given for the underlaid portion.Polypropylene interrupted horizontal mattresssutures are placed but left untied initially untilall sutures are in position, to ensure even dis-tribution of tension. The patch should be tautbut not excessively tight. The omentum flap is

FIG. 1. Exit points of the omentum flap. In the subcostalregion, the right side is preferred, as liver prevents herniationof bowel.

FIG. 2. Cross-section of the anterior abdominal wall showing the omentumpassing through an oblique passage created by separating the oblique musclesand spreading the layers open like the slits of a venetian blind.

1716 PLASTIC AND RECONSTRUCTIVE SURGERY, November 2005

then gently spread over the Gore-Tex andloosely tagged down with absorbable sutures.The skin is closed directly or with myocutane-ous flaps. Closed suction drainage is applied.All patients are given abdominal binders post-operatively for additional support for at least 6months while the repair matures.

RESULTS

The mean follow-up of the patients was 18months (range, 8 to 47 months). Table I sum-marizes the outcome. One patient developed asubcutaneous abscess 6 months postopera-tively. On computed tomographic imaging, theomentum was seen to have contained the in-fection, and this was successfully treated bypercutaneous drainage and systemic antibiot-ics. The others had uneventful postoperativerecovery. The reconstructed areas manifested aslight bulge, but there was no hernia. No intra-abdominal complications related to the use ofthe omentum flap were noted.

CASE REPORTS

Case 1A 57-year-old diabetic man presented with a large right

iliac fossa incisional hernia (Fig. 3). He had had an appen-dicectomy previously and subsequently developed an inci-sional hernia that failed multiple attempts at repair. Polypro-pylene mesh was used three times and, in all instances,infection developed, necessitating mesh removal. At the timeof surgery, the hernia sac and overlying skin were excised. Inaddition, a length of small bowel measuring 150 cm wasresected to reduce the volume of abdominal viscera. Theresultant full-thickness defect measuring 22 � 18 cm wasrepaired with Gore-Tex and covered with the greater omen-tum based off the right gastroepiploic vessels (Fig. 4, above

and center). The omentum was brought into the subcutaneousplane by means of a 4-cm right subcostal incision. A pedicledanterolateral thigh musculocutaneous flap was used to re-construct the skin defect (Fig. 4, below). The patient healeduneventfully and was discharged. However, 6 months later,the patient spontaneously developed an abdominal wall ab-scess over the reconstructed site because of poor diabeticcontrol. A computed tomographic scan showed a collectionbelow the anterolateral thigh flap that was walled off by theomentum. The abscess was successfully treated by percuta-

TABLE ISummary of Patients with Abdominal Wall Defects Repaired with Gore-Tex and Omentum Flap

PatientNo.

Age(yr)/Sex Diagnosis

DefectDimensions (cm)

OmentumExit Points

AdditionalFlap Used Outcome

1 57/Male Recurrent incisionalhernia over theright lower quadrant

22 x 18 cm Right subcostal Pedicled anterolateralthigh myocutaneousflap; vertical rectusabdominis myocutan-eous flap

Subcutaneous abscess at6 mo.; resolved withpercutaneous drainage;vertical

2 36/Female Recurrent sarcomaof the lateralabdominal wall

15 x 20 cm Lateral abdominalwall at the lineasemilunaris

Latissimus dorsi muscleflap, used internallywith the omentumflap

Excellent

3 53/Male Osteosarcoma of thelower rib involvingthe diaphragm andlateral abdominal wall

25 x 18 cm Lateral abdominalwall at the lineasemilunaris

Direct skin closure Excellent

4 45/Male Lateral abdominalwall sarcoma

15 x 10 cm Lateral abdominalwall at the lineasemilunaris

Direct skin closure Excellent

FIG. 3. The patient in case 1, presenting with a large in-cisional hernia over the right iliac fossa. Multiple previousattempts at repair were unsuccessful.

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neous drainage and systemic antibiotics. At 9-month follow-up, the reconstructed abdominal wall was intact and there wasno recurrence of the hernia (Fig. 5).

Case 2A 36-year-old woman presented with recurrent sarcoma

over her upper lateral abdominal wall. She had a history ofeleventh rib fibromyxoid sarcoma excised 13 years previously.Intraoperatively, tumor was noted to involve the entire thick-ness of the abdominal wall. However, there was no invasion

of the peritoneum or the pleura space. Wide excision resultedin a full-thickness lateral abdominal wall defect measuring 15� 20 cm (300 cm2). Reconstruction was performed usingGore-Tex in the usual fashion (Fig. 6, above). The omentumwas transposed extraperitoneally through a 4-cm openingover the lateral abdominal wall (Fig. 6, center). An inferiorlybased vertical rectus abdominis myocutaneous flap was fash-ioned for skin coverage (Fig. 6, below). She recovered un-eventfully. At 3-year follow-up, the repair was noted to beintact and she had no complications (Fig. 7).

DISCUSSION

The main rationale for using the omentumflap as an additional cover over the Gore-Tex wasto prevent exposure of the prosthesis in the eventof flap breakdown, given that in two of the fourcases, myocutaneous flaps were used for skincover because of accompanying skin defects. Hadthere been flap necrosis, we would have beenable to perform skin grafting over the omentum.The value of the interposed omentum was real-ized in the patient in case 1, who developed asuppurative infection over the prosthesis 6months after the initial operation. Althoughthere was skin breakdown, the prosthesis was notexposed. Thus, the infection was treated conser-

FIG. 4. (Above) Reconstruction with Gore-Tex placed inan underlay fashion. The greater omentum was pedicledbased on the right gastroepiploic vessels and brought into thesubcutaneous plane by means of a 4-cm subcostal incision atthe right linea semilunaris. (Center) The Gore-Tex was com-pletely covered by the omentum flap. (Below) A right pedicledanterolateral thigh fasciocutaneous flap was raised to coverthe skin defect.

FIG. 5. The patient in case 1 at 9 months postoperatively.All wounds had healed completely and there was no recur-rence of the hernia.

1718 PLASTIC AND RECONSTRUCTIVE SURGERY, November 2005

vatively by percutaneous drainage without dis-mantling the repair.

Even with intact skin, the presence of a largesynthetic sheet may still result in seroma forma-tion, infection, and extrusion.1 These complica-tions could be attributed to factors such as thepresence of dead space, lymphatic disruption,and subcutaneous fat, which integrates poorlywith prosthetic material. The omentum, consist-ing of abundant blood vessels, fat, and lymphat-ics, is known for its unique immunologic and

angiogenic properties. By using it as an interpo-sitional flap, we harness such properties to facil-itate wound healing4,5 and promote soft-tissueintegration with Gore-Tex. Muscle has similarqualities, and it was used to supplement theomentum in the patient in case 3 (Table I). Inthis patient, the Gore-Tex sheet had extendedfrom the flank to the chest, and the latissimusdorsi muscle flap was used to cover the chestportion.

The use of alloplastic material for fascial recon-struction has the advantages of avoiding donor-site morbidity and reducing operation time. Weprefer the Gore-Tex DualMesh over other syn-thetic materials for its dual surface properties.The smooth inner surface is nonadhesive tobowel and reperitonealizes over time.6 Its cordu-roy outer surface promotes tissue integration.7Because it is biocompatible and has low infect-ability, the risk of implant extrusion is low.8–11

From a technical standpoint, the underlay place-ment technique offers a mechanical advantage be-cause the forces generated by intraabdominal pres-sure tend to hold the patch in place. Pedicledomentum flaps will usually reach defects over allquadrants of the abdominal wall. When additionallength is needed, the omentum is elevated fromthe transverse colon and transposed based on bothgastroepiploic vessels. Yet further reach is obtainedwhen one set of the gastroepiploic vessels is ligated.The flap will survive on collateral circulation fromthe arch of Barkow.5,12–14 The right gastroepiploicvessel is usually the larger of the two vessels. Theexit point of the flap in each patient was carefullydesigned to reduce the risk of hernia formation

FIG. 6. (Above and center) The patient in case 2 after sar-coma resection. The abdominal wall was reconstructed withGore-Tex, and an omentum flap was used to line it. (Below)A vertical rectus abdominis myocutaneous flap was used forskin cover.

FIG. 7. The patient in case 2 at 3 years after surgery. Therewere no complications or contour abnormalities.

Vol. 116, No. 6 / OMENTUM FLAP 1719

(Figs. 1 and 2); however, the opening should beadequate to avoid constricting the flap. We couldhave passed the omentum through the main de-fect, where a small opening is created by leaving theGore-Tex unstitched. However, this was avoided, asit could have compromised the repair. Indicationsfor our described technique include abdominalwall reconstruction in immunocompromised pa-tients such as diabetics and in patients who havehad previous mesh infection or radiation therapy tothe vicinity. This technique is also useful in patientsfor whom large quantities of prosthetic materialswere used for repair.

Some potential drawbacks of the techniqueare as follows: Gore-Tex, as is the case with allalloplastic materials, cannot be used in contami-nated fields, although in theory, the omentumwrap may protect against infection. The omen-tum is not always available; previous omentec-tomy from procedures such as colectomy or gas-trectomy would mean that this “life boat” ismissing and an alternative has to be sought. Al-though not seen in this series, there was a theo-retical risk of herniation through the exit pointsof the omentum flap. Also, having been exterior-ized, the omentum is no longer present to pro-tect the abdominal viscera. This may be a poten-tial problem in children or in patients in whomthere are critical bowel reconstructions.

Bien-Keem Tan, F.R.C.S.Department of Plastic, Reconstructive, and

Aesthetic SurgerySingapore General HospitalOutram Road Singapore 169608bienkeem@singnet.com.sg

ACKNOWLEDGMENTS

The authors thank Winston Chew, M.D., and Soo-PingChew, M.D., of the Tan Tock Seng Hospital for their collab-orative efforts in this study.

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