Flow-through anterior thigh flaps with a short pedicle for reconstruction of lower leg and foot defects

New flow-through perforator flaps with a large, short vascular pedicle are proposed because of their clinical significance and a high success rate for reconstruction of the lower legs. Of 13 consecutive cases, the authors describe two cases of successful transfer of a new short-pedicle anterolateral or anteromedial thigh flow-through flap for coverage of soft-tissue defects in the legs. This new flap has a thin fatty layer and a small fascial component, and is vascularized with a perforator originating from a short segment of the descending branch of the lateral circumflex femoral system. The advantages of this flap are as follows: flow-through anastomosis ensures a high success rate for free flaps and preserves the recipient arterial flow; there is no need for dissecting throughout the lateral circumflex femoral system as the pedicle vessel; minimal time is required for flap elevation; there is minimal donor-site morbidity; and the flap is obtained from a thin portion of the thigh. Even in obese patients, thinning of the flap with primary defatting is possible, and the donor scar is concealed. This flap is suitable for coverage of defects in legs where a single arterial flow remains. It is also suitable for chronic lower leg ulcers, osteomyelitis, and plantar coverage.     

Closure of hemicorporectomy with bilateral subtotal thigh flaps

Hemicorporectomy is typically performed with a circumferential truncal incision, and the wound is closed primarily. Wound disruption is a common complication, especially at the base of the wound closure and posteriorly at the lumbar vertebral level. We report a case of the use of bilateral subtotal thigh flaps for the closure of a hemicorporectomy wound in a patient with a defect extending up to the high lumbar region. The subtotal thigh flap is a well-vascularized thick flap that provides a firm support for the abdominal viscera and is a large flap that can be used to close even a high lumbar defect.     

Use of free thin anterolateral thigh flaps combined with cervicoplasty for reconstruction of postburn anterior cervical contractures

Free thin anterolateral thigh flaps combined with cervicoplasty were used in a series of seven patients undergoing reconstruction for previous burn injury from September of 2000 to May of 2001 at Chang Gung Memorial Hospital. This method uses a suprafascial dissection technique to provide a thin flap to improve cervical contour. Neck contractures had resulted from flame burns in six patients and from a chemical burn in one patient. The mean age was 32.7 years (range, 22 to 45 years). The size of excised scar ranged from 10 x 2 cm to 26 x 5 cm (mean, 19.7 x 3.3 cm). The size of flaps ranged from 11 x 5 cm to 26 x 8 cm (mean, 21.3 x 6.5 cm). Average operative time was 6 hours. Average hospital stay was 10 days. All flaps survived, with one flap sustaining partial marginal loss. The donor site was closed primarily in five cases and by using a split-thickness skin graft in two cases. At a mean follow-up time of 5 months, the functional improvement was measured as follows: a mean increase in extension of 30 degrees (preoperatively, 95 degrees; postoperatively, 125 degrees), a mean increase in rotation of 18 degrees (preoperatively, 59 degrees; postoperatively, 77 degrees), and a mean increase in lateral flexion of 12.5 degrees (preoperatively, 26.5 degrees; postoperatively, 39 degrees). The average cervicomandibular angle was improved by 25 degrees (preoperatively, 145 degrees; postoperatively, 120 degrees). This series demonstrates that the use of free thin anterolateral thigh flaps combined with cervicoplasty provides a one-stage reconstruction with a thin, pliable flap that achieves good cervical contour with low donor-site morbidity.     

Two new cutaneous free flaps: the medial and lateral thigh flaps

Two new cutaneous free-flap donor areas are described on the medial and lateral sides of the thigh. The medial thigh flap is supplied by an unnamed artery from the superficial femoral artery and is drained by the accompanying venae comitantes. Its nerve supply is from the medial femoral cutaneous nerve. The lateral thigh flap has its vascular pedicle from the third perforating artery of the profunda femoral artery and its accompanying vein. The lateral femoral cutaneous nerve provides sensation over the area. These flaps provide a large surface area of both skin and subcutaneous tissue without the usual bulk of subcutaneous fat and muscle. Their desirable features include long vascular pedicles with large vessel diameters and potential of being neurovascular flaps with specific sensory nerve supply and predictable anatomy. The principal disadvantage is that the donor site may leave a slight contour defect with primary closure or require grafting when a large flap is taken. We predict that these flaps will become important donor sites for reconstructive problems requiring resurfacing of cutaneous defects in various anatomic areas.     

Anterolateral thigh fasciocutaneous island flaps in perineoscrotal reconstruction

This study presents the authors' experience using the anterolateral thigh fasciocutaneous flap for complex perineal and scrotal reconstruction. Anterolateral thigh fasciocutaneous island flaps were performed in seven patients between January and June of 2000 (six male, one female; mean age, 52 years; age range, 9 to 72 years). Four of the seven patients had scrotal or perineal defects after multiple debridements for Fournier's gangrene. Two of these four had exposed testicles. Three flaps were used for recurrent ischial ulcers. A true septocutaneous perforator (type 1) running between the rectus femoris and the vastus lateralis muscles was found in only two patients. In four patients, the cutaneous perforators were found to be intramuscular, originating from the descending branch (type 2). In the other patient, the musculocutaneous perforator originated from the lateral circumflex femoris artery independently (type 3). In these cases, intramuscular dissections were performed to follow each perforator to its main trunk. Mean follow-up was 8 months (range, 5 to 10 months), and all flaps survived. Three patients developed minor wound dehiscence in the posterior aspect of the perineal wound because of fecal contamination and skin maceration. Both wounds healed secondarily. Scrotal reconstruction with the anterolateral thigh flap gave an excellent aesthetic result. The authors conclude that the anterolateral thigh flap is a reliable flap for perineoscrotal reconstruction.     

Preoperative color Doppler assessment in planning of anterolateral thigh flaps

The anterolateral thigh flap has many advantages, but it has not yet achieved widespread use because the perforators exhibit considerable anatomical variation and their locations are difficult to predict preoperatively. The authors performed a prospective study to investigate whether acoustic Doppler flowmetry and color Doppler ultrasonography were helpful for preoperative localization of the perforators in anterolateral thigh flaps. Ten patients scheduled for anterolateral thigh flap surgery were examined preoperatively with both acoustic Doppler flowmetry and color Doppler ultrasonography, and all points where the perforators seemed to penetrate the fascia lata were mapped. The actual perforating points were identified intraoperatively and were compared with the preoperatively mapped points. Fifteen perforators were detected in 10 patients. The concordance rate with acoustic Doppler flowmetry was 40 percent (95 percent confidence interval, 15 to 68 percent; p = 0.05). In contrast, the concordance rate with color Doppler ultrasonography was 100 percent (95 percent confidence interval, 81 to 100 percent; p = 0.05). Color Doppler examination was significantly more accurate than acoustic Doppler examination (determined by the binomial test; p < 0.0014). Three-dimensional anatomical information around the perforators was further useful in elevating flaps. The authors conclude that color Doppler examination can accurately identify the perforators and is useful for planning in anterolateral thigh flap surgery, whereas acoustic Doppler examination is unreliable.     

The revascularization of pedicle skin flaps in pigs: a functional and morphologic study

Functional and morphologic changes occurring during the revascularization of pedicle flaps have been investigated in the skin of pigs. The skin flaps, 16 cm long by 4 cm wide, were based on a row of segmental vessels arising from the internal mammary artery. Comparative measurements were made in flapped and normal skin. The inherent blood supply in the pedicle of the flap was unable to maintain the whole of the flap in a viable state. Flap viability was ascertained at surgery by the use of the intravital dye Disulphine blue. Injections of the dye after surgery gave a less accurate prediction of viability than when dye was injected prior to surgery. Revascularization between the flap and surrounding skin was evident 3 to 4 days postoperatively at the distal, most hypoxic part of the viable flap. The whole flap had a collateral vascular supply 7 to 10 days after surgery. Isotope clearance studies showed that the greatest functional changes occurred in the distal third of the viable flap, where, after initially slowing, the clearance rate became faster than in normal skin (day 5). Potassium extraction studies indicated similar changes. However, an increase in the red-cell volume on day 1 suggested that vascular shunting was occurring. The results of the morphologic studies indicated a correlation between the number of blood vessels per unit area, the thickness of the dermis, and the recorded functional changes. Seven days after surgery, when isotope clearance rates were very rapid, there was a significant increase in the vascular density and dermal thickness.     

Enhanced neovascularization of rat tubed pedicle flaps with low perfusion of the wound margin

To study the role of ischemia due to low perfusion as the inciter of neovascularization, caudally based 3 X 9 cm skin flaps were created on the dorsum of 50 Sprague-Dawley rats. After injection of 0.2 ml 10% fluorescein, the animals were divided into two groups. In group I (n = 25), the distal margin of the flap tip was 1 cm proximal to the border of the fluorescence (good perfusion). In group II (n = 25), the flap was cut 1 cm distally in the nonfluorescent part (poor perfusion). The tips of the tubed flaps were transferred to a wound bed on the right flank. After 10 days, the pedicles were ligated, so that flap survival depended totally on the new vascular supply from the inset area of the flap. The flaps in group I showed a significantly higher rate of necrosis of 52.4 +/- 15.1 percent versus 1.7 +/- 1.4 percent in group II (p less than 0.0001), although the flap length in group I (5.85 +/- 1.16 cm) was less than in group II (7.15 +/- 0.95 cm; p = 0.0001). A nearly three times larger amount of tissue based on the new blood supply survived in group II compared to group I. Xerograms after injection of PbO2-gelatine on day 10 showed an increased ingrowth of blood vessels in group II. After excluding the delay phenomenon as the cause for the difference in necrosis rate, it is concluded that the only possible explanation is an enhancement of neovascularization by a perfusion gradient between the wound margins.