British Journalof’Plastic Surgery (1988), 41,551-553 0 1988 The Trustees of British Association of Plastic Surgeons

Case report

External oblique musculocutaneous flap for the reconstruction of a lumbo-sacral defect

S. SAKAI, S. SOEDA and A. MATSUKAWA

Unit of Plastic Surgery, Institute of Clinical Medicine, University of Tsukuba, and Department of Dermatology, Mito Red Cross Hospital, lbaraki, Japan

Summary-Thisreport describesacaseof lumbo-sacral radiation ulcerwhich wastreatedsuccessfully by an external oblique musculocutaneous flap supplied mainly by the subcostal artery.

Case report

A 63-year-old woman was referred with a radiation ulcer of the lumbo-sacral area, present for several years. She had undergone a radical hysterectomy and radiotherapy for uterine cancer about 15 years previously. The ulcer had twice been treated unsuccessfully by local flaps and skin grafts.

Examination revealed a deep ulcer extending to the spinous processes of the lumbar vertebrae and measuring 10 x 9 cm (Fig. 1). Under general anaesthesia and in the left lateral position with a pillow under the flank, a wide excision of the irradiated area was carried out, creating a 12 x 11 cm skin and subcutaneous defect (Fig. 2A). Because !here did not seem to be a flap from the back able to CO\V such a large defect, a 13 x 27 cm right external oblique musculocutaneous flap was designed (Fig. 2B). This flap was raised, including skin, subcuta- neous tissue and external oblique muscle and fascia. It was supplied by the subcostal artery and the perforating cutaneous branches of the upper part of the lumbar arteries (Fig. 2C, D). The flap was elevated from anterior to posterior and the pedicle dissected as far as its emergence from the anterior margin of the latissimus dorsi muscle. This allowed the flap to reach to the sacral area easily without tension. It was necessary to raise a small portion of the internal oblique muscle and trans- verse abdominis to avoid damage to the vascular pedicles but these muscle defects were closed easily after the pillow under the body was removed. The flap was transferred to the defect (Fig. 2E) and the donor site covered with a mesh skin graft (Fig. 2F). Healing was uneventful (Fig. 3A, B).

Our patient has been followed up for 2 years, with no recurrence of the ulcer and no development of abdominal herniation.

Discussion

It is difficult to repair a large lumbo-sacral radiation ulcer. Local flaps are simple and useful for small

defects but are usually inadequate for larger ones (Hester et al., 1982). For these, distant and free flaps are available. Flaps supplied by the intercostal neurovascular bundles have been developed and used for reconstruction of lumbo-sacral defects (Dibbell, 1974; Daniel et al., 1976, 1978; Kerrigan and Daniel, 1979; Little et al., 198 1) but the pedicles

Fig. 1

Figure l-Deep radiation ulcer of the lumbo-sacral area and scars of the previous treatments.

551

552 BRITISH JOURNAL OF PLASTIC SURGERY

Obhqws Internus

Obliquus Externus

dges of Transversus

Abdominis & Obliquus Internus

Fig. 2

Figure 2-(A) The 12 x 11 cm skin and subcutaneous defect. (B) Design of the 13 x 27 cm right external oblique musculocutaneous flap. (C) Elevation of the flap. (D) Diagrammatic representation of this flap which is supplied by the subcostal artery and the perforating cutaneous branches of the lumbar arteries. (E) Immediate postoperative result.

must be long if the flap is to reach to the defect. Two or three intercostal vascular pedicles are usually necessary and they are easily damaged. If such a flap cannot reach the defect, reconstruction may need several stages. Free flap techniques (Nabai and Hagerty, 1985) need experienced microsurgeons and microsurgical instruments which are not always available.

The external oblique muscle has been thought to have a limited application for a musculocutaneous flap (Hershey and Butcher, 1964) because of its short arc of rotation and the weakening of the abdominal wall at the donor site (Nahai and Mathes, 1982). However, it may have more appli-

cations than these authors thought if the patient is selected appropriately and alternative flaps are not available. The external oblique muscle originates from the fifth to the twelfth rib and inserts into half of the outer lip of the iliac crest and the linea alba. It is supplied with branches of the intercostal vessels from T5 to T12 and lumbar arteries (Mathes and Nahai, 1982). Hodgkinson and Arnold (1980) reported a case of chest wall reconstruction using the external oblique muscle flap successfully but did not mention the number and nature of the pedicles they used.

If the T12 and lumbar arteries are used for supplying this flap, it can be raised far posteriorly

EXTERNAL OBLIQUE MUSCULOCUTANEOUS FLAP FOR THE RECONSTRUCTION OF A LUMBO-SACRAL DEFECT 553

Fig. 3

Figure 3-(A) 2 years after operation. The flap has covered the involved lumbo-sacral area successfully. (B) Donor site without abdominal or lumbar herniation.

without damaging the pleura. When it is transposed to the lumbo-sacral area, the pedicles are not compressed by ribs. Flaps pedicled by intercostal arteries without muscle components are available but, for the reconstruction of an irradiated ulcer, the musculocutaneous flap is more reliable than any other local flaps without muscle because of its excellent blood supply, and its bulkiness resists the effects of pressure (Badran et al., 1984; Fisher, 1985). The sacrifice of the external oblique muscle is said to weaken the abdominal wall and produce abdominal herniation but the remaining two com- ponents of internal and transverse abdominal muscle seem to be able to support it adequately (Arnold, 1982). This has certainly been the case with our patient.

References

Arnold, P. C. (1982). Reconstruction of the chest wall. In Mathes, S. J. and Nahai, F. (Eds) Clinical Applifations for Muscle and Musculocutaneous Flaps. St Louis, Toronto, London: The C. V. Mosby Co.

Badran. H. A.. El-Helalv. M. S. and Safe. I. (1984). The lateral , , “I I ~ I

intercostal neurovascular free flap. Plastic and Reconstructive Surgery, 73. 17.

Daniel, R. K., Kerrigan, C. L. and Gard, D. A. (1978). The great potential of the intercostal flap for torso reconstruction. Plastic and Reconstructive Surgery, 61,653.

Daniel, R. K., Terzis, J. K. and Cunningham, D. M. (1976). Sensory skin Raps for coverage of pressure sores in paraplegic patients; a preliminary report. Plastic and Reconstructive Surgery, 58, 3 17.

Dibbell, D. G. (1974). Use of a long island flap to bring sensation to the sacral area in young paraplegics: case report. Plastic and Reconstructive Surgery. 54,220.

Fisher, J. (1985). External oblique fasciocutaneous flap for elbow coverage. Plastic and Reconstructive Surgery, 75, 5 1.

Hershey, F. B. and Butcher, H. R. (1964). Repair of defects after uartial resection of the abdominal wall. American Journal of Surgery, 107, 586.

Hester, T. R., Schneider, W. J. and Hal, H. L. (1982). Pressure sores: reconstruction. In Mathes. S. J. and Nahai. F. (Eds) Clinical Applications for Muscle and Musculocutaneaus klaps; St Louis, Toronto, London: The C. V. Mosby Co.

Hodgkinson, D. J. and Arnold, P, G. (1980). Chest wall reconstruction using the external oblique muscle. British Journal of Plastic Surgery, 33,216.

Kerrigan, C. L. and Daniel, R. K, (1979). The intercostal flap: an anatomical and hemodynamic approach. Annals of Plastic Surgery, 2,411.

Little, J. W., Fontana, D. J. and McCuUoeh, D. T. (1981). The upper-quadrant flap. Plastic and Reconstructive Surgery, 68, 175.

Mathes, S. J. and Nahai, F. (1982). Clinical Applications for Muscle and Musculocutaneous Flaps. St Louis, Toronto, London : The C. V. Mosby Co.

Nahai, F. and Hagerty, R. (1985). One-stage microvascular transfer of a latissimus flap to the sacrum using vein grafts. Plastic and Reconstructive Surgery, 77, 3 12.

Nahai, F. and Mathes, S. J. (1982). Complications. In Mathes, S. J. and Nahai, F. (Eds) Clinical Applications for Muscle and Musculocutaneous Flaps. St Louis, Toronto, London: The C. V. Mosby Co.

The Authors

Shigenobu Sakai, MD, Instructor, Unit of Plastic Surgery, Institute of Clinical Medicine, University of Tsukuba, l-l-l Sakura-mura, Niihari-gun, Ibaraki 305, Japan.

Shugo Soeda, MD, Professor, Unit of Plastic Surgery, Institute of Clinical Medicine, University of Tsukuba.

Atam Matsukawa, MD, Director of Dermatology, Mito Red Cross Hospital, Ibaraki.

Requests for reprints to Dr Sakai.

Paper received 28 October 1987. Accepted 19 February 1988 after revision.