The ad hoc perforator flap for contracture release☆

Surgical technique 

Careful Doppler mapping, preliminary exploration, or both, are carried out to identify a perforator adjacent to the contracture to be released. The site of such a perforator is the would-be pivot point of the flap. A non-committal exploratory incision is then made adjacent to the defect to be reconstructed, and the skin and soft tissues are raised at a fasciocutaneous level (Fig. 1). Through this wound, the perforator that was the origin of the positive Doppler signal is sought. Once the perforator is identified, two issues need to be considered. First, the direction the perforator takes after piercing the fascia and, second, its potential vascular territory. This is essential for correct planning and design of the flap. Loupe magnification is usually sufficient to identify the direction of the perforator and, in the extremities, it is usually safer to design an island flap in which the perforator enters the flap distally. This allows transposition of the flap from proximal to distal. Determining the potential vascular territory of the flap is a matter of fine judgment. Factors to consider include the size of the perforator and also the presence of any other significant adjacent perforators that would, by necessity, be sacrificed in order to facilitate the transfer of the flap as an island. The greater the number of perforators in an area, the less the size of the potential territory of individual perforators.11 If a flap is particularly large (i.e. in Fig. 1), a non-crushing intestinal clamp is applied to make sure that the circulation at the distal margin is adequate. Once this is verified, the flap can be completely islanded and transposed. With careful planning, most donor sites can be closed primarily, although a split-skin graft may be required in some circumstances.

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Figure 1 Surgical technique: (a) large axillary sheet contracture; (b) after release of the axillary contracture a large fasciocutaneous flap is raised with a musculocutaneous perforator (blue marker) identified at site corresponding to preoperative Doppler signal; (c) before islanding the flap a soft bowel clamp is applied; (d) having established viability, the flap is completely islanded and transposed to cover the defect; (e) 3 months after surgery.

The maximum flap dimensions achievable are unclear. The largest flap length to width ratio in this study is approximately 5:1 (Fig. 2).

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Figure 2 (a) Sheet contracture to right flank; (b) ad-hoc perforator flap raised on partially scarred skin; (c) the result 5 years after surgery.

Patients 

A retrospective case-note and photographic analysis was carried out for all patients undergoing burn or joint contracture release by the senior author at St Johns Hospital, Livingston or the Royal Hospital for Sick Children, Edinburgh between the years 2000 and 2005. Twenty patients who had contracture release and reconstruction with a total of 23 ad-hoc perforator flaps were identified. All patients had release of burn contractures, with the exception of one patient who had an axillary contracture secondary to debridement and skin-grafting of a necrotising infection. The locations of the flap reconstructions can be seen in Table 1. Most (15 of 23) involve the upper extremity.

Table 1. Location of flaps

	Anatomical site	Number of flaps
	Shoulder/axilla	8
	Upper limb	7
	Trunk	3
	Lower limb	3
	Groin	1
	Natal cleft	1

Eleven of the 20 patients were children (median age 12 years, range 8–15 years). The median hospital stay was 2 days (range 1–12 days). Many of the cases would have been suitable for day-case surgery, but were kept overnight owing to long travelling distances between the hospital and their home. All donor sites were closed primarily, apart from one patient who required a split-skin graft to close the donor site. One significant complication occurred, which involved complete flap loss secondary to unrecognised intraoperative damage to the pedicle (Fig. 3). Had this been recognised at the time of surgery, the salvage option would have been to thin the flap and replace it as a full-thickness skin graft. This would also be the salvage option if no reliable perforator can be found. One patient experienced significant hypertrophic scarring at the donor site, and another required liposuction and thinning of a moderately bulky flap. Median follow-up was 9 months (range 2 months to 5 years). No patient has required revisional surgery for contracture recurrence where this technique has been used.

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Figure 3 Flap loss secondary to unrecognised pedicle damage.

Axilla 

The patient in Fig. 4 had a moderate anterior axillary fold contracture, which was interfering with shoulder abduction. An ad-hoc perforator flap has been raised and rotated 180° into the defect.

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Figure 4 (a) Anterior axillary fold contracture with flap rotated 180° into defect; (b) appearance at 3 months.

Cubital fossa 

The technique has been found to be particularly useful around the cubital fossa. A patient with an ad-hoc perforator flap raised on partially scarred skin from the superolateral aspect of the left cubital fossa is shown in Fig. 5.

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Figure 5 (a) Cubital fossa contracture released with ad-hoc perforator flap; (b) appearance at 3 months.

Trunk 

This man had an old burn to the right flank with an extensive grafted area causing a sheet contracture. The tightest area of the contracture was released and interposed with an ad-hoc perforator flap raised on partially scarred skin (Fig. 2a,b). However, a previously skin-grafted area at the lower aspect of the right flank has contracted with time, whereas the perforator flap has stretched with time (Fig. 2c).

Popliteal fossa 

This young man (Fig. 6) had a longitudinal, unstable post-burn contracture across the lateral limit of the right popliteal fossa, limiting full extension of the knee. An ad-hoc perforator flap was raised on the posterior thigh skin and rotated 90° into the defect resulting from contracture release. A full range of knee movement was achieved after surgery.

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Figure 6 (a) Lateral band limiting knee extension; (b) ad-hoc perforator flap islanded and inset after contracture release; (c) postoperative result with full range of knee movement.

Multiple flaps 

Where indicated, it is easy to carry out more than one flap at the same time. This 8-year old child (Fig. 7) has a large longitudinal contracture stretching from the iliac crest to the axilla. Three ad-hoc flaps have been designed to break up the contracture at three levels. Postoperative healing was uneventful.

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Figure 7 (a) Longitudinal contracture from iliac crest to axilla; (b) three ad-hoc perforator flaps designed on scarred skin; (c) all flaps completely islanded and donor sites closed primarily.