BritishJournal of Plastic Surgery (1977), 30, 166-168

A LARGE ROTATION FLAP RAISED ACROSS THE MIDLINE TO CLOSE

LUMBO-SACRAL MENINGOMYELOCOELES

By DAVID DAVIES, F.R.C.S.(Eng.) and D. J. ADENDORFF, F.R.C.S.(Ed.) Department of Plastic Surgery, Red Cross War Memorial Hospital,

Cape Town, South Africa

PATERSON (1959) stated that in about a quarter of cases of meningomyelocoele, closure of the skin defect was not possible by direct suture with or without relieving incisions. In the smaller of such defects a single lateral flap based superiorly or inferiorly will suffice for closure. For very large defects, the method described by Mustarde (1968) has much to recommend it. In between these 2 extremes are defects apparently too large for a single flap and 2 flaps are often used. The disadvantage of double flaps is that the suture line which unites them, overlies the spinal defect and if any vascular insufficiency develops it is here that breakdown occurs with possible disruption of the underlying repair. We have used a transverse bipedicled flap but such flaps are under intermittent tension as the child’s back is flexed, actively or passively. In addition, in our experience, the advancement actually obtained with a bipedicled flap is less than expected.

In 5 patients we have used a large rotation flap which transgresses 2 of the rules usually applied to random pattern flaps: it may be half as long again as it is broad and it crosses the midline. The defects which were covered averaged 73 x 6 cm.

TECHNIQUE

The timing of the operation was decided by the neurosurgeon who also carried out the dural and fascial repair. Planning of the flap was undertaken with a piece of surgical lint so that absolutely no tension would be present. The length : breadth ratio of the flap was never more than 14 : I but even this requires a frightening amount of the superior back skin. Ornithine-8-vasopressin (P.O.R.8) was infiltrated around the perimeter of the proposed flap and at least 5 minutes elapsed before the first incision. With a combination of sharp and blunt dissection the flap was lifted on the deep fascia and transposed to cover the defect. A partial-thickness skin graft was applied to the donor area.

RESULTS

In 4 of the 5 cases, primary healing occurred (Fig. I) and the patients were dis- charged about the 10th day postoperatively. In the last case managed in this manner, marginal skin necrosis occurred with breakdown of the suture line requiring resuturing (Fig. 2). Fortunately no cerebra-spinal fluid leak occurred. The complication in this last flap was due, we felt, to a technical error in that too high a diathermy current for

166

A LARGE ROTATION FLAP 167

FIG. I. Superior transposition flap providing skin cover for a large lumbosacral meningomyelocoele. (a) 6 days postoperatively. (b) 8 months later.

FIG. 2. (a) Meningomyelocoele preoperatively. (b) 3 days after rotation of the flap. Note linear pattern of necrosis due probably to vessel damage from diathermy. of the donor area and the actual amount of skin loss.

(c) 4 weeks postoperatively. Note shrinkage There was no disruption of the underlying repair

and the small defect was easily closed.

168 BRITISH JOURNAL OF PLASTIC SURGERY

haemostasis was used, there having been no evidence of circulatory embarrassment during the operation.

DISCUSSION

It was with some trepidation that the first large superior laterally based flap that crossed well over the midline was cut. However, in the neonate the watershed effect is perhaps not so critical and the initial results with the flap have been rewarding. Its advantages are: the suture line is at the edges of the meningomyelocoele defect and with minor skin loss no exposure of the deeper repair should occur; tension can be completely eliminated; and the thin atrophic skin of doubtful viability can usually be excised with impunity.

REFERENCES

MUSTAFXIE, J. C. (1968). Reconstruction of the spinal canal in severe spina bifida. Plastic and Reconstructive Surgery, 42, 109.

PATERSON, T. J. S. (1959). The use of rotation flaps for excision of lumbar meningomye- locoele. British Journal of Surgery, 46, 606.