The Use of Unilateral or Bilateral External Oblique Myocutaneous

Flap in the Reconstruction of Lower Abdominal Wall or Groin

Defects After Malignant Tumor Resection

RUMING ZHANG, MD,1,2* CHUNMENG WANG, MD,1,2 YONG CHEN, MD,1,2

BIQIANG ZHENG, MD,1,2 AND YINGQIANG SHI, MD1,2

1Department of Gastric Cancer and Soft Tissue Sarcomas, Fudan University Shanghai Cancer Center, Shanghai, China2Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China

Background: External oblique myocutaneous flap (EOMF) has been used successfully for many years in reconstructive plastic surgery, its functionis mainly concentrated in the restoration of chest wall defects following breast cancer resection. However, for the lower abdominal wall or groindefects after malignant tumor resection, reconstruction with EOMF is little reported. In this study, we report our experience with EOMF downwardtransposition to repair the defects.Methods: 12 patients with malignant diseases in the lower abdominal wall or groin underwent aggressive tumor resection, the defects werereconstructed immediately with EOMF. Patient characteristics, details of operation and postoperative complications were described.Results: 12 patients received radical resection, the defect size ranged from 140 to 588 cm2. Ipsilateral or bilateral EOMF was utilized to repair thedefects. The EOMF had good quality skin and soft tissue to cover the defects, postoperatively, four patients developed seroma, two patients had distaltip necrosis, but no serious complications occurred, the wound of donor site healed well, no abdominal hernia was found.Conclusion: Our study provides a new and alternative approach to reconstruct large defects with EOMF downward transposition after malignanttumor resection in the lower abdominal wall or groin.J. Surg. Oncol. 2014;110:930–934. � 2014 Wiley Periodicals, Inc.

KEY WORDS: external oblique myocutaneous flap; lower abdominal wall; groin; reconstruction

INTRODUCTION

Lower abdominal wall or groin defects result frommultiple etiologies,including tumor resection, trauma, infection, and wound dehiscence [1].Such defects require flexible and sophisticated closure, especially formanagement of refractory and large tumors in the regions, aggressivelylocal excision is necessary to attain optimal effects with clean surgicalmargin and reduced recurrence [2,3]. However, after massive softtissue resection, immediate reconstruction of the skin and soft tissuedefects is indispensable and challenging. Although rectus abdominisflap [4,5], anterolateral thigh flap [6], and tensor fascia lata flap [7] havebeen used to reconstruct the defects, it is still controversial to designmoreappropriate flap for the treatment of these malignant diseases.

External oblique myocutaneous flap (EOMF) is frequently utilized inthe reconstruction of chest wall defects following advanced breastcancer excision, and studies show that it has the capability of extendingfar beyond the anatomic territory, it represents an effective way forcoverage of chest wall defects [8,9]. However, to our knowledge, EOMFhas been seldom applied in the restoration of defects after radical tumorresection in the lower abdominal wall or groin.

In our study, unilateral or bilateral EOMFwas used to reconstruct lowerabdominal wall or groin defects following tumor resection, the resultsshown that the flap could flexibly provide adequate soft tissue coverage forthe defects. Our experience and view on this flap are presented.

PATIENTS AND METHODS

Patients

From 2005 to 2013, 12 patients (seven males and five females) withmalignant disease in the lower abdomen wall or groin were treated bytumor resection and immediate EOMF reconstruction at Shanghai

Cancer Center of Fudan University or Shuguang Hospital affiliatedShanghai University of Traditional Chinese Medicine, the follow‐uptime was more than 6 months for each patients. With the institutionalreview board approval, the surgical treatment was performed,patient demographics, treatment histories, flap types, postoperativecomplications were summarized in Table I.

Tumor History

Four patients had dermatofibrosarcoma protuberanses, two hadmalignant fibrous histiocytomas, the others were diagnosed asliposarcoma, soft tissue osteosarcoma, vascular myopericytoma,fibrosarcoma, metastatic squamous cell carcinoma, and metastaticadenocarcinoma for one patient each. Of these patients, 10 cases werediagnosed as tumor recurrence, 4 cases had received radiotherapy, thedata were summarized in Table I.

Disclosures: There are no potential conflicts of interest with regard to thispaper.

*Correspondence to: Dr. Ruming Zhang, MD, Department of Gastric Cancerand Soft Tissue Sarcomas, Fudan University Shanghai Cancer Center;Department of Oncology, Shanghai Medical College, Fudan University,Shanghai 200032, China. Fax: 86‐21‐64430130.E‐mail: rumingzhang@126.com

Received 8 March 2014; Accepted 28 July 2014

DOI 10.1002/jso.23763

Published online 25 August 2014 in Wiley Online Library(wileyonlinelibrary.com).

Journal of Surgical Oncology 2014;110:930–934

� 2014 Wiley Periodicals, Inc.

METHODS

Unilateral EOMF Technique

After sufficient resection of tumor located in the one side of lowerabdominal wall or groin, an incision at the abdominal median line wasmade from defect area to the point 2 cm above the xiphoid with the depthto anterior rectus sheath, the anterior rectus sheath was included in thisflap. Then lateral separation into the gap between external obliquemuscle and internal oblique muscle was performed, the dissection of theEOMF was laterally extended around the anterior axillary line (no morethan the mid‐axillary line). The upper transverse incision of the flap wasclose to the nipple (approximately the 5th rib) and axilla, the attachmentof external oblique muscle to the ribs was cut off. The EOMF was notseparated until it was satisfied to cover the defect, the umbilicus waspreserved, drains were placed, the flap was sutured in place withthe incision edges in the lower abdominal wall or groin. The hipshould be kept in flexion to reduce incisional tension for 4 weeks aftersurgery (Fig. 1).

Bilateral EOMF Technique

After sufficient excision of tumor located over the abdominalmidline, the transverse incisions were extended from the upper cornersof defect to bilateral sides, even reached beyond the anterior superioriliac spine. There were two ways to free the flap, one was the stealthmethod: an incision about 10 cm at the thoracoabdominal median linewas made from the point 2 cm above the xiphoid to the lower abdomen.Then, from this incision the flap including the right and left sides wassubcutaneously separated (Fig. 2), other procedures were similar withUnilateral EOMF Technique. When the defect was very large, the openmethod was recommended, an additional transverse incision through thelower edge of the areola was required from the point 2 cm above thexiphoid to the bilateral sides of axillary line, so the bilateral flaps couldbe more fully separated (Fig. 3), other procedures were performed inaccordance with Unilateral EOMF Technique.

RESULTS

The patients were all diagnosed with malignant diseases, the datawere summarized in Table I, the lesions were located in the groin in 7patients, and in the lower abdominal wall in 5 patients. Among 12patients, 10 patients were diagnosed as recurrent diseases and 2 patientsas primary diseases. Four patients had received irradiation treatment. All12 patients underwent radical neoplasm resection, the defect areas variedfrom 14� 10 cm to 14� 42 cm (from 140 to 588 cm2), the average areawas 290 cm2. To cover the defects, unilateral or bilateral EOMF was

exploited. For tumor located in the one side of lower abdominal wall orgroin, unilateral EOMF was used to cover the defect (Fig. 1). For tumorlocated over the abdominal midline, bilateral EOMF should be utilized(Fig. 2), however, when the defect was very large (Fig. 3), the bilateralEOMF could not be fully separated by the stealth method (seen in themethods), the open method (seen in the methods) should be considered,the result shown that the large defect in the lower abdominal wall couldbe well repaired with EOMF downward transposition by the openmethod (Fig. 3). One patient had underwent 7 surgeries for theermatofibrosarcoma protuberans in the left groin, the disease relapsedand invaded the left thigh, after total tumor resection, we took advantageof the ipsilateral EOMF and left scrotum to repair the large defect,meanwhile, the left testicle was removed, after operation, the patienthealed well (Fig. 1). In three cases, besides use of EOMF to repair, weutilized artificial materials (artificial blood vessel seen in Fig. 2, Bardpatch seen in Fig. 3) to enhance the strength of the defect area.Pathological analysis confirmed that all the tumors were resected withR0 resection.

Our results showed that the EOMFwas efficient in closing the defectsin all 12 patients, no serious complications occurred after surgery, thewound of donor site healed well, no abdominal hernia was found in thesepatients. Four patients suffered seroma postoperatively, and they all hada radiotherapy history, indicating irradiation increased the risk ofseroma. Two patients had distal tip necrosis, the wounds healedspontaneously without infection. No secondary procedure was requiredfor these patients. During follow‐up evaluation for at least 6 monthsafter surgery, one case diagnosed with vascular myopericytoma hadunderwent radiotherapy and 3 surgeries, one year later after ouroperation, the patient developed local recurrence and died of lungmetastasis. One case was lost to follow up. No local recurrence andventral hernia were observed in other ten cases.

DISCUSSION

Cancer is a leading cause of human death worldwide [10]. For tumorsarising from the region of lower abdominal wall or groin, there are fewstudies to investigate, although surgery, radiotherapy, chemotherapy,and biological target therapy have been employed, surgery is consideredas the primary approach in the treatment of these malignant diseases.Especially, for those patients with tumor relapse or undergoingradiotherapy, aggressive resection is still necessary to get negativesurgical margins, immediate reconstruction is indispensable andchallenging. In this study, we explored a new approach to reconstructthe lower abdominal wall or groin defects with EOMF after tumorresection, our results indicate that this flap can flexibly provide adequatesoft tissue coverage for large defects in the areas.

TABLE I. Patient Summary

Case Sex Age Location PathologyRelapse(times) Radiation

Defect size(cm2) Reconstruction (EOMF) Complication

1 Male 76 Groin Malignant fibrous histiocytoma 3 No 20� 16 Unilateral None2 Male 62 Groin Dermatofibrosarcoma protuberans 7 No 18� 15 Unilateralþ scrotum None3 Female 65 Groin Vascular myopericytoma 3 Yes 18� 13 Unilateral seroma4 Female 19 LAW Dermatofibrosarcoma protuberans 0 No 20� 13 Unilateral None5 Female 36 LAW Dermatofibrosarcoma protuberans 3 No 15� 10 Unilateral None6 Male 56 Groin Malignant fibrous histiocytoma 5 Yes 14� 13 Unilateral seroma7 Male 61 Groin Dermatofibrosarcoma protuberans 1 No 20� 13 Unilateral Distaltip necrosis8 Male 30 Groin Soft tissue osteosarcoma 1 No 14� 10 Unilateral None9 Female 37 LAW Liposarcoma 2 Yes 21� 17 Unilateralþ patch seroma10 Female 57 LAW Metastatic SCC from cervix 0 Yes 42� 14 Bilateralþpatch seroma11 Male 54 LAW Metastatic adenocarcinoma 1 No 20� 18 Bilateraþ patch Distaltip necrosis12 Male 62 Groin Fibrosarcoma 3 No 20� 18 Unilateral None

LAW: Lower abdominal wall, SCC: squamous cell carcinoma.

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Reconstruction of Lower Abdominal Wall or Groin 931

Fig. 1. The use of unilateral EOMF in the reconstruction of lower abdominal wall defect. Design of an ipsilateral flap extending to the lowerabdominal wall defect (above left); EOMF elevation after tumor resection (above right); closure of the defect using EOMF and left scrotum (belowleft); view of the flap 7 years later (below right).

Fig. 2. The use of bilateral EOMF in the reconstruction of lower abdominal wall defect. The CT scan of the tumor in the lower abdominal wall(above left); design of bilateral EOMF and tumor resection (above right); bilateral EOMF separation with the stealth method and reconstruction withpatch (below left), the patch consisted of two longitudinally open artificial blood vessels which were sutured together; view of the flap in a latepostoperative time (below right).

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932 Zhang et al.

The EOMF is a large, strong and flat abdominal muscle, as a flap issuccessfully applied in closing large defects after advanced breast cancersurgery [8,9,11], however, there are few reports on the use of EOMF inreconstructing the lower abdominal wall or groin defects. In ourexperience, we found EOMF was useful to cover the defects in theseareas, for tumor mainly located in the one side of lower abdominalwall or groin, ipsilateral EOMF was enough to cover the defectfollowing tumor resection. But for tumor located over the abdominalmidline, unilateral EOMF was insufficient, bilateral EOMF should beutilized to repair the defect. Of 12 patients, 10 cases were performedwithunilateral EOMF reconstruction, other 2 cases with bilateral EOMFreconstruction. EOMF can be classified as an extended flap, we tookadvantage of the laxity of skin in the up‐lateral chest wall, EOMF couldbe downward transferred up to 10 cm, in our patients, the maximumdistance reached 14 cm. When defect included the inner thigh, we usedthe scrotal skin for coverage (Fig. 1), the local thigh flap or skin graft canalso be considered to reconstruct the thigh defect. The repair of defectswas satisfied in our 12 patients, no serious complications happened, thedonor site healed well. In the recipient sites, four patients who all hadunderwent radiotherapy developed postoperative seroma, for 8 casesthat had never had a radiotherapy, no seroma occurred, indicating

radiation increases the risk of seroma, as radiation is harmful for tissuehealing, cavity is prone to form. For management of the seromas, syringewas used in the drainage of the fluid collections, pressure dressing wasutilized for reducing the dead space. From our experience, the treatmentwith the pressure dressing was very important and necessary for thesepatients, and the seromas gradually improved. EOMF is a sturdy andgood blood supplied myocutaneous flap. After the separation, it is stillsensate and largely innervated by the branches of the intercostals nervesfrom the location of the lateral mid‐axillary line. The blood supply isfrom the branches of the intercostals and lumbar arteries, in accordancewith this, only two patients had a necrosis at the distal tip of the flap. Bychanging dressings frequently, the necrosis healed conservatively.Taken together, The EOMF is a versatile flap in reconstructive plasticsurgery not only for the defects of chest wall, but also for the defects oflower abdominal wall and groin.

To reconstruct the defects in the lower abdominal wall or groin aftertumor resection, a few methods have been introduced to close thedefects, but it is still controversial to design appropriate flap for thesepatients. The tensor fascia lata (TFL) flap [7,12] has been reported that itis useful to cover the defects, but the donor site may require a skin graft,a hernia can still be a possible complication. The rectus abdominis

Fig. 3. The use of bilateral EOMF in the reconstruction of large lower abdominal wall defect. The MRI scan of the tumor in the lower abdominalwall (above left); design of bilateral EOMF and tumor resection (above right); large defect after tumor resection (middle left); bilateral EOMFseparation with the openmethod and reconstruction with Bard patch (middle right); immediate postoperative view of the flap (below left); view of theflap 22 months later (below right).

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Reconstruction of Lower Abdominal Wall or Groin 933

(RA) flap has been used for groin and perineal reconstruction [4,13],postoperatively, this flap can lead to abdominal wall weakness.LoGiudice and colleagues (6) conduct a review on 39 patientsthat underwent lower abdominal wall or groin reconstruction withanterolateral thigh (ALT) flap or (and) RA flap, the results show thatALT flap is superior to RA flap for covering the defects in theareas. Ramzy [14] reports that the rectus femoris muscle flap issuitable for reconstruction of groin defect resulting from inguinallymphadenectomy, but a postoperative rehabilitation program may berequired for the donor site morbidity. Yang [15] recently reports thatlower abdominal wall defects can be reconstructed by the use ofthe combined technique of intraperitoneal mesh placement, sublaytechnique, pedicled great omentum flap and rotation skin graft, however,the use of mesh increases the potential risks of relative complications,and the contour is uneven and unsmooth when compared withmusculofascicutaneous flap. In our series, 11 of 12 patients had everunderwent operation or (and) radiation therapy, three patients hadreceived the two treatments, even one case had 7 surgeries. Afteraggressive tumor resection in these oncologic patients, the pathologicalexamination confirmed that the resection margins were negative.Obviously, the reconstruction was difficult, but we found that the EOMFwas an alternative and reliable reconstructive choice, the EOMFwas notdifficult to harvest, could effectively cover the defects in the lowerabdominal wall or groin, the donor site needed no skin graft, the flaphad good quality skin to cover the defect, and also showed idealthickness with an even contour, the rectus abdominis remained intact,postoperatively, there was absence of abdominal‐wall weakness, noabdominal hernia occurred in our patients. Like other flaps [16],the EOMF also has the potential to be applied to these diseases suchas wound‐healing difficulties, infections, exposed native vessels andradiation‐induced ulcers in these areas.

Taken together, we use a new approach to reconstruct the skin andsoft tissue defects after tumor resection in the lower abdominal wallor groin. EOMF should be considered as a reliable and effective optionto restore the defects in these areas, especially for tumor patients havingunderwent repeated relapse and (or) radiotherapy. For defect located inthe one side of lower abdominal wall or groin, unilateral EOMF is usedto cover the defect, for defect located over the abdominal midline,bilateral EOMF should be utilized. However, more cases are requiredto confirm our observation.

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