Utility of the Omentum in the Reconstruction of Complex Oncologic Perineal Defects

Authors: C. Scott Hultman, MD; Matthew Sherrill, MD; Clara Lee, MPH, MD; Sumeet Teotia, MD; Benjamin Calvo, MD; Michael Meyers, MD; David Ollila, MD; John Boggess, MD; Hong Jin Kim, MD

Purpose: Myocutaneous flaps have documented efficacy in the reconstruction of complex perineal defects after tumor extirpation,1 but the utility of the omentum as a primary or as an additional flap has not been rigorously examined.2,3 Theoretical benefits of the omentum in pelvic floor reconstruction include providing vascularized tissue to a previously irradiated region, improving lymphatic drainage, and decreasing the risk of perineal hernia and bowel obstruction.4,5 The purpose of this study was to assess the usefulness and safety of the omentum in the reconstruction of complex perineal defects, following abdomino-perineal resection (APR) or pelvic exenteration for anorectal malignancy.

Methods: We performed a retrospective review of 51 consecutive patients who had APR or pelvic exenteration for anorectal malignancy, over a 4-year period, at a university teaching hospital. Patients were identified from a prospectively maintained cancer registry, and data regarding age, stage, medical co-morbidities, prior radiotherapy (XRT), method of reconstruction (primary repair, myocutaneous flap, and/or omental flap), and length of follow-up were collected. Regarding operative technique, omental flaps were based on a single vascular pedicle, tunneled in the retrocolic plane lateral to the ligament of Treitz, and transposed across the sacrum to the pelvic floor. Main outcome measures included operative blood loss (EBL), length of stay (LOS), incidence and management of complications, and survival. Major complications were defined as intra-abdominal or pelvic abscess requiring drainage, hematoma requiring evacuation, bowel obstruction, need for re-operation, and flap loss. Patients who were reconstructed with omental flaps (n=22) were compared with patients who did not receive omental flaps (n=29), using Student’s t test and chi-square analysis, with statistical significance assigned to p values < 0.05.

Results: From 2000-2004, 51 patients (mean age 58.7 years, range 32-86 years) with anorectal malignancy underwent APR (n=45) or pelvic exenteration (n=6). Incidence of major complications was significantly lower for patients who had omental flaps (4/22, 18%), compared to patients who did not have omental flaps (15/29, 52%) (*p=0.01). Complications in the omental flap group included perineal abscess (n=1), intra-abdominal abscess (2), perineal hematoma (1), and re-operation (n=3), with no morbidity related to the omental flaps. In contrast, complications in the no omentum group included perineal abscess (n=8), intra-abdominal abscess (n=2), reoperation (n=5), small bowel obstruction (n=4), fistula (n=1), and urinoma (n=1). No significant differences were observed regarding age, stage, XRT (39/51 patients), method of reconstruction, EBL (mean 914 ml), and survival. Myocutaneous flaps were used in 9/22 (41%) patients in the omental flap group, compared to 14/29 (48%) patients in the no omentum group, and included rectus abdominis (n=16), gracilis (n=5), and gluteus (n=2), plus 3 additional gluteal flaps for failed primary repairs (all in the no omentum group). Length of stay was slightly longer for the omental flap group compared to the no oemtnum group (14.1 vs 11.8 days), but this did not reach statistical significance. Mean length of follow-up was 304 days (range: 9-1597 days), with 50/51 patients surviving to discharge and 43/51 patients alive at the end of the study period.

Age
(years) / XRT / EBL
(ml) / Myocutaneous
flap / LOS
(days) / Complications / Survival
Omental flap n=22 / 59.9 / 18 (82%) / 847 / 9 (41%) / 14.1 / 4 (18%) / 19 (86%)
No omentum n=29 / 57.8 / 21 (72%) / 925 / 14 (48%) / 11.8 / 15 (52%) / 24 (83%)
P value / NS / NS / NS / NS / NS / *0.01* / NS

Conclusions: Use of the omentum as a primary flap, or in combination with a myocutaneous flap, in the reconstruction of complex perineal defects is associated with a decreased incidence of post-operative complications. This documented efficacy strongly supports the use of the omentum in perineal reconstruction after APR or pelvic exenteration for anorectal malignancy.

References:

  1. Khoo AK, Skibber JM, Nabawi AS, et al. Indications for immediate tissue transfer for soft tissue reconstruction in visceral pelvic surgery. Surg 2001;130:463-469.
  2. Moreaux J, Horiot A, Barrat F, Mabille J. Obliteration of the pelvic space with pedicled omentum after excision of the rectum for cancer. Am J Surg 1984;148:640-644.
  3. Smith SRG, Swift I, Gompertz H, Baker WNH. Abdominoperineal and anterior resection of the rectum with retrocolic omentoplasty and no drainage. Br J Surg 1988;75:1012-1015.
  4. Kiricuta I, Goldstein AMB. The repair of extensive vesicovaginal fistula with pedicled omentum: A review of 27 cases. J Urology 1972;108:724-727.
  5. 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 1975-2000. Ann Surg 2002;235:782-795.