RECONSTRUCTIVE Comparison of Vertical and Oblique Rectus Abdominis Myocutaneous Flaps for Pelvic, Perineal, and Groin Reconstruction Patrick D. Combs, M.D. Janelle D. Sousa, M.D. Otway Louie, M.D. Hakim K. Said, M.D. Peter C. Neligan, M.B., B.Ch. David W. Mathes, M.D. Seattle, Wash.
Background: Wound complications after perineal and groin obliterative procedures are a significant cause of morbidity, particularly following chemoradiation therapy. Vertical and, increasingly, oblique rectus abdominis myocutaneous flaps have been used to fill potential dead space and bring healthy, vascularized tissue into the defect. The authors compared the complications and outcomes of patients undergoing perineal or groin reconstruction with vertical or oblique rectus abdominis myocutaneous flaps. They hypothesized that the oblique flap offers outcomes similar to those of the vertical flap, without an increased risk of complications. Methods: All patients who underwent immediate reconstruction of perineal, pelvic, or groin defects using vertical (n = 49) or oblique rectus abdominis myocutaneous (n = 22) flaps over the past 10 years at the University of Washington Medical Center were reviewed retrospectively. Patient, disease, and obliterative procedure characteristics and donor- and recipient-site complications were compared. Statistical analysis was performed using the t test for continuous variables and Fisher’s exact test for categorical variables. Results: There were no statistically significant differences in major or minor donor- or recipient-site complication rates, need for augmented fascial closure, need for additional flaps, flap loss, readmission, or reoperation rate between the two groups. Conclusions: Immediate reconstruction of perineal or groin defects with oblique rectus abdominis myocutaneous flaps results in complication rates similar to those with reconstruction using with vertical flaps. Oblique flap reconstruction is a reasonable and safe alternative, providing several distinct advantages over the vertical flap, including greater arc of rotation, thinner skin paddle, less bulk, and limited fascial harvest. (Plast. Reconstr. Surg. 134: 315, 2014.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.
erineal and groin wounds are a significant cause of patient morbidity following resection for malignant or inflammatory processes. This is especially true when the extirpative surgery is performed after treatment with external beam irradiation. Wound dehiscence, delayed healing, and abscess formation remain significant risks following these obliterative procedures. The From the Division of Plastic Surgery, University of Washington. Received for publication December 6, 2013; accepted February 18, 2014. Presented at the 56th Annual Meeting of the Plastic Surgery Research Council, in Louisville, Kentucky, April 28 through 30, 2011. Copyright © 2014 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000000324
complication rate in the literature ranges from 25 to 60 percent following primary closure of abdominoperineal resection defects1–7 and from 32 to 84 percent following pelvic exenteration.8–11 Poor healing of these wounds has been attributed to large defects with noncollapsible dead spaces, bacterial contamination, and the healing difficulties inherent in a poorly vascularized, often irradiated field.1,3,12 Thus, primary closure of large, complex perineal and groin defects is usually not a viable option. The high frequency of postoperative complications has led to reconstructive strategies designed to mitigate known risk factors and complications. Disclosure: The authors have no financial interest to declare in relation to the content of this article.
Plastic and Reconstructive Surgery • August 2014 Transfer of a soft-tissue flap into the defect serves to fill the pelvic dead space; incorporate healthy, well-vascularized tissue into the wound; allow for concomitant vaginal reconstruction when needed; and facilitate tension-free closure. Multiple musculocutaneous and fasciocutaneous flaps have been used for this purpose, including inferior gluteal artery–based flaps,13–16 anterolateral thigh flaps,17–19 gracilis flaps,10,20,21 and rectus abdominis flaps. The vertical rectus abdominis myocutaneous flap has emerged as a workhorse for pelvic, perineal, and groin reconstruction. Proponents cite several advantages, including reliability of the skin paddle, adequate bulk for obliteration of the dead space, and donor site within the existing abdominal wound.1,12,22 Multiple series have demonstrated a decreased rate of wound complications with immediate reconstruction of pelvic and perineal wounds with vertical rectus abdominis myocutaneous flaps.1,3,9,23 A variation of the vertical rectus abdominis myocutaneous flap with an obliquely oriented skin paddle based on periumbilical perforators has been described historically as the extended rectus abdominis myocutaneous flap and, more recently, as the oblique rectus abdominis myocutaneous flap.24–27 Potential advantages, including a long, thin skin paddle, increased reach and arc of rotation, ease of elevation and donor-site closure, and limited rectus fascia harvest, make the oblique rectus abdominis myocutaneous flap an attractive alternative to the vertical rectus abdominis myocutaneous flap for management of complex perineal and groin wounds. Two recent retrospective series by Lee and Dumanian26 and Abbott et al.28 demonstrate the efficacy of immediate oblique rectus abdominis myocutaneous reconstruction of these defects. The clinical utility and positive results have led to increased use of the oblique rectus abdominis myocutaneous flap at our institution. We hypothesize that the oblique rectus abdominis myocutaneous flap could offer more reconstructive flexibility than the vertical rectus abdominis myocutaneous flap without any increase in complication rates for reconstruction of complex perineal, pelvic, and groin wounds.
PATIENTS AND METHODS All patients who underwent vertical and oblique rectus abdominis myocutaneous flap reconstruction of perineal, pelvic, and groin wounds at a large academic tertiary referral center between January of 2001 and January of 2010 were identified using a departmental database. Patients
were excluded if the rectus muscle without a skin paddle was used for reconstruction. The study was approved by the institutional review board. Data on patient characteristics, underlying disease necessitating resection, resection and flap inset characteristics, postoperative donor- and recipient-site complications, hospital stay, need for further operative intervention, and duration of follow-up were obtained from the medical record. Patient characteristics included age, sex, tobacco use within 6 months of surgery, diabetes, nutritional status defined as albumin level greater than or less than 3 g/dl, immunosuppression status, and exposure to radiation preoperatively. Follow-up was measured in months and defined as the time from surgery to the last documented visit to our institution in which the surgical site was examined. Operative characteristics included the disease process necessitating surgery, obliterative procedure performed, location of flap skin paddle inset, and need for additional flaps used in reconstruction during the primary procedure. In some cases, the anterior rectus fascia was unable to be closed. This was managed either by leaving the anterior fascia open or by repairing the fascial defect with biological or absorbable mesh. Postoperative complications were categorized as donor-site complications, recipient-site complications, necessity for a salvage flap, reoperation, and surgery-related readmission. The inset of six flaps (three oblique and three vertical rectus abdominis myocutaneous flaps) involved complete deepithelialization of the skin paddle and burial of the flap, limiting postoperative assessment of flap viability. These flaps were excluded from postoperative evaluation of recipient-site complications. For both donor and recipient sites, surgicalsite infection and superficial dehiscence were combined and categorized as minor or major. Minor surgical-site infection/superficial dehiscence events were managed by antibiotics or bedside exploration. Major surgical-site infection/superficial dehiscence events, and donor-site fascial dehiscence, required operative intervention. Incisional hernias were diagnosed by history, physical examination, and computed tomographic imaging of the abdomen. Flap loss was categorized as partial, in which there was incomplete loss of the skin paddle, and complete, in which the entire skin paddle necrosed. Flap congestion was characterized objectively by signs of venous congestion on physical examination. Total hospital stay was measured in days, and included the length of the hospitalization in which the procedure was
Volume 134, Number 2 • Flaps for Perineal Reconstruction
Fig. 1. Vertical rectus abdominis myocutaneous flap.
performed, and the length of any additional surgery-related readmissions. Operative Technique Vertical rectus abdominis myocutaneous flaps were elevated based on the inferior epigastric artery. The skin paddle was designed in size and orientation according to the specific recipient-site defect. All skin paddles were centered over the carrier rectus muscle (Fig. 1). The entire rectus muscle was harvested from its origin at the costal margin to the insertion on the pubis. When used for groin reconstruction, exposed muscle was covered with a split-thickness skin graft. When used for perineal reconstruction, the flap was elevated on the side opposite the proposed ostomy site. Oblique rectus abdominis myocutaneous flaps were designed contralateral to the proposed ostomy site. Periumbilical perforators were identified using a Doppler probe and marked with an indelible marker or sutures. The skin paddle was designed with the base directly over the periumbilical perforators, extending obliquely toward the tip of the scapula, no farther lateral than the anterior axillary line (Fig. 2). Flap width was determined using a pinch test. After skin incisions, the flap was elevated off the external oblique fascia from lateral to medial. On approach of the marked perforators, dissection proceeded through the rectus fascia, and a fascial cuff including the perforators was incorporated into the flap (Fig. 3). The inferior epigastric artery and vein were dissected toward their origin, with the entire rectus muscle harvested (Fig. 4). After disinserting the rectus muscle from the pubis, the skin paddle was partially deepithelialized, leaving sufficient skin for tension-free wound closure at
Fig. 2. Markings for oblique rectus abdominis myocutaneous flap incisions.
the recipient site (Fig. 5). The fascia was repaired primarily, reconstructed with bioprosthetic or absorbable mesh, or left open, and then the donor site was closed in layers over a closed-suction drain (Fig. 6). Statistical Analysis Statistical analysis was performed using the t test for continuous variables and Fisher’s exact test for categorical variables. Values of p < 0.05 were considered significant. Statistical analysis was performed using SAS 9.2 software (SAS Institute, Inc., Cary, N.C.), Microsoft Excel 2008 (Microsoft Corp., Redmond, Wash.), and GraphPad Prism 4.03 (GraphPad Software, Inc., La Jolla, Calif.).
Fig. 3. Oblique rectus abdominis myocutaneous flap elevation.
Plastic and Reconstructive Surgery • August 2014
Fig. 6. Oblique rectus abdominis myocutaneous flap donor-site closure. Fig. 4. Oblique rectus abdominis myocutaneous flap with muscle harvest.
RESULTS Patient Characteristics A total of 71 rectus abdominis myocutaneous flaps were used for perineal, pelvic, and groin reconstruction in 71 patients. This included 49 vertical rectus abdominis myocutaneous flaps performed by five surgeons, and 22 oblique rectus abdominis myocutaneous flaps performed by four surgeons. Patient characteristics and length of follow-up are listed in Table 1. There were no statistically significant differences in patient age, sex, tobacco
use, premorbid diabetes, immunosuppression, or preoperative radiation therapy between the vertical and oblique rectus abdominis myocutaneous flap patient groups. Nutritional status was the only characteristic that was significantly different between the two groups, with more patients in the oblique rectus abdominis myocutaneous group having an albumin level less than 3 g/dl (p = 0.04). The mean length of follow-up was longer in the vertical rectus abdominis myocutaneous flap group; however, the difference was not statistically significant. Operation Characteristics Operation characteristics are listed in Table 2. The distribution of disease necessitating operation was similar between the two groups. The most common diagnosis in each group was rectal adenocarcinoma, followed by anal carcinoma, cervical cancer, and perineal or groin sarcoma. The two most common resection procedures in each group were abdominoperineal resection and pelvic exenteration. In Table 1. Patient Characteristics
Fig. 5. Oblique rectus abdominis myocutaneous flap perineal skin paddle.
No. of patients Age, yr Sex Male Female Tobacco use Diabetic Albumin level