Experience with thirteen latissimus dorsi myocutaneous free flaps.

Subcutaneous "pocketing" is proposed as a simple and convenient method to nourish a denuded, replanted end of a finger, when the amputation is between the lunule and the DIP joint. The investigation of a laboratory model is presented, and our initial clinical experience is reported.     

Use of thirty latissimus dorsi flaps

Experiences with 30 latissimus dorsi flaps are described. Used either as a muscle flap, as a myocutaneous flap, or as an "island" of skin nourished by a subcutaneous pedicle of muscle and vessels, the flap has an excellent blood supply and is suitable for many repairs of defects of the chest wall.     

Vascular endothelial growth factor expression in pig latissimus dorsi myocutaneous flaps after ischemia reperfusion injury

Exogenous administration of vascular endothelial growth factor (VEGF) improves long-term viability of myocutaneous flaps. However, endogenous expression of this substance in flaps following ischemia-reperfusion injury has not been reported previously. Endogenous production of VEGF was measured in myocutaneous pig latissimus dorsi flaps after ischemia-reperfusion injury. Latissimus dorsi myocutaneous flaps (15 x 10 cm) were simultaneously elevated bilaterally in six Yorkshire-type male pigs (25 kg). Before elevation, three flap zones (5 x 10 cm) were marked according to their distance from the vascular pedicle. After isolation of the vascular pedicle, ischemia-reperfusion injury was induced in one flap by occlusion of the thoracodorsal artery and vein for 4 hours, followed by 2 hours of reperfusion. The contralateral flap served as a control. Perfusion in each zone was monitored by laser Doppler flowmetry at baseline, during ischemia, and during reperfusion. At the end of the protocol, skin and muscle biopsies of each flap zone and adjacent tissues were obtained for later determination of VEGF protein levels. VEGF concentrations were quantified using the Quantikine human VEGF immunoassay. Skin perfusion was similar among all flap zones before surgery. Flow fell in all flaps immediately after flap elevation. After 4 hours of ischemia, blood flow in the ischemic flaps was significantly decreased (p < 0.05) compared with nonischemic control flaps. After 2 hours of reperfusion, flow in ischemic flap skin recovered to levels similar to those in control flaps. VEGF protein concentrations in muscle tissue exceeded concentrations in skin and decreased from zones 2 to 3 in control and ischemic flaps. No significant differences in VEGF concentrations between ischemic and control muscle zones were observed. However, the concentration of VEGF in all muscle zones was significantly higher (p < 0.05) than muscle adjacent to the flap. Concentrations in skin zones 1 and 2 were significantly higher (p < 0.05) in ischemic flaps than in control flaps, but levels in zone 3 (most ischemic flaps) showed no significant difference.     

Simultaneous bilateral breast reconstruction using latissimus dorsi myocutaneous flaps: a retrospective review of an institutional experience

A single institution's experience in the simultaneous reconstruction of both breasts using bilateral latissimus dorsi myocutaneous flaps is presented. The procedure was performed on 24 patients by the attending staff of the department of plastic surgery at St. Joseph Hospital in Houston, Texas, between 1979 and 1999. Of the 24 patients reviewed, six had immediate reconstructions, 13 had delayed primary reconstructions, and five had secondary reconstructions of failed or unsatisfactory primary procedures. In the group with delayed reconstructions, the average time between mastectomy and reconstruction was 46.4 months, with a range from 7 days to 21 years. The operative method, results, and outcomes of our experience in these patients is presented.     

Vascularization of the myocutaneous latissimus dorsi flap. Injection study on the thoracodorsal artery

This study reports on investigations of the thoracodorsal artery by injection studies. This artery has a long proximal extramuscular course before it enters the muscle. A consistent neurovascular hilum was found at a considerably constant location on the inferior muscle surface, 2-3 cm medial to its lateral edge and about 5 cm distal to the inferior scapular border. A constant branching pattern of the thoracodorsal artery into a lateral and a medial vessel stem was found. A high number of muscle-perforating arteries from a dense network in the cutaneous and subcutaneous layer. The thoracodorsal artery supplies the whole cutaneous area adjacent to the latissimus dorsi muscle plus a streak of about 2 cm at the medial and distal muscle borders. The presented anatomical landmarks are useful for locating the neurovascular hilum, and the intramuscular course of the thoracodorsal artery for exploration of the vessel by Doppler sonography or dissection. The length of the pedicle and the relatively big vessel gauge are good anatomical markers for the free transfer of a latissimus dorsi flap.     

Two options for perforator flaps in the flank donor site: latissimus dorsi and thoracodorsal perforator flaps

Two types of perforators, septocutaneous and musculocutaneous, are found in the same donor site of the flank area, and two perforator flaps based on each perforator are clinically available. Therefore, it is necessary to distinguish them from one another using different nomenclatures. Accordingly, the perforator flap based on a musculocutaneous perforator is named according to the name of the muscle perforated, the latissimus dorsi perforator flap, and the perforator flap based on a septocutaneous perforator, located between the serratus anterior and latissimus dorsi muscles, is named according to the name of the proximal vessel, the thoracodorsal perforator flap. In this series of 42 latissimus dorsi perforator flaps, flap size ranged from 5 x 3 cm to 20 x 15 cm, and two complications were observed: a marginal necrosis in an extremely large flap (26 x 12 cm) and a failure caused by infection. The thoracodorsal perforator flap was used in 14 cases, including two cases of chimeric composition. Flap size ranged from 4.5 x 3.5 to 18 x 15 cm, with no complications. In the two patterns of perforator flap that the author used, initial temporary flap congestion was observed in five latissimus dorsi perforator flap cases and two thoracodorsal perforator flap cases, when the flap was designed as a large flap or a less reliable perforator was selected. However, the congestion was not serious enough to cause flap necrosis. Several techniques, such as T anastomosis or inclusion of an additional perforator or a small portion of muscle, are recommended to prevent the initial flap congestion, especially when an unreliable perforator is inevitably used or when a flap larger than 20 cm long is required. A small portion of the muscle was included in six cases, when an unduly large or improperly long flap was planned. All of the flaps were successful and ranged from 22 x 7 to 15 x 28 cm, except for one case of distal flap necrosis in an extraordinarily large flap measuring 34 x 10 cm. Diverse selection of the perforator flap is one of the great advantages of the flank donor site, providing it with wider availability and more versatile composition for reconstruction or resurfacing.     

Preconditioning of latissimus dorsi muscle flaps with monophosphoryl lipid a

The use of dynamic myoplasty to restore function to failing organs is an exciting new application of skeletal muscle flaps. A complication of large flap elevation that can compromise flap function is ischemia-induced necrosis; one approach to minimizing this is to pretreat tissues with ischemic preconditioning. The purpose of this study was to determine whether systemic administration of monophosphoryl lipid A, a drug known to mimic late-phase ischemic preconditioning in the heart, could reduce ischemia-induced necrosis in latissimus dorsi muscle flaps. Forty latissimus dorsi muscle flaps from 20 Sprague-Dawley rats were allocated into four groups. In group I (n = 10), flaps were not preconditioned and served as controls. In group II (n = 10), flaps received ischemic preconditioning with two 30-minute periods of ischemia interspersed by 10 minutes of reperfusion. In group III (n = 10), rats received an intravenous bolus of approximately 0.3 ml of monophosphoryl lipid A vehicle only. In group IV (n = 10), rats received an intravenous bolus of 450 microg/kg of monophosphoryl lipid A and vehicle. Twenty-four hours after treatment, all latissimus dorsi muscle flaps were elevated on a single neurovascular pedicle and subjected to 4 hours of ischemia. After 72 hours of reperfusion, latissimus dorsi muscles were harvested, weighed, stained with nitroblue tetrazolium, and assessed for percent necrosis using digitized images of muscle sections and computerized planimetry. The percent necrosis in ischemic preconditioning-treated flaps (group II) was significantly reduced by 57 percent (p < 0.05) compared with control flaps (group I). The percent necrosis in flaps treated with monophosphoryl lipid A (group IV) was significantly reduced by 58 percent (p < 0.05) compared with vehicle-control flaps (group III). There was no difference in mean percent necrosis between ischemic preconditioning (group II) and monophosphoryl lipid A-treated (group IV) flaps or between ischemic preconditioning-control (group I) and monophosphoryl lipid A vehicle-control (group III) flaps. Intravenous administration of systemic monophosphoryl lipid A mimics the late-phase protective effect of ischemic preconditioning in the authors' rat latissimus dorsi muscle flap model.     

Reducing the vascular delay period in latissimus dorsi muscle flaps for use in cardiomyoplasty

Although the mechanism by which vascular delay benefits skin flaps is not completely understood, this topic has been extensively studied and reported on in the literature. In contrast, little has been documented about the effects of vascular delay in skeletal muscle flaps. Recent animal studies tested the effectiveness of vascular delay to enhance latissimus dorsi muscle flap viability for use in cardiomyoplasty and found that it prevented distal flap necrosis. However, these studies did not define the optimal time period necessary to achieve this beneficial effect. The purpose of this study was to determine how many days of "delay" can elicit the beneficial effects of vascular delay on latissimus dorsi muscle flaps. To accomplish this, 90 latissimus dorsi muscles of 45 male Sprague-Dawley rats were randomly subjected to vascular delay on one side or a sham procedure on the other. After predetermined delay periods (0, 3, 7, 10, and 14 days) or a sham procedure, all latissimus dorsi muscles were elevated as single pedicled flaps based only on their thoracodorsal neurovascular pedicle. Latissimus dorsi muscle perfusion was measured using a Laser Doppler Perfusion Imager just before and immediately after flap elevation. The muscles were then returned to their original vascular beds, isolated from adjacent tissue with Silastic film, sutured into place to maintain their original size and shape, and left there for 5 days. After 5 days, the latissimus dorsi muscle flaps were dissected free, scanned again (Laser Doppler Perfusion Imager-perfusion measurements), and the area of distal necrosis was measured using digitized planimetry of magnified images. The authors' results showed that delay periods of 3, 7, 10, and 14 days significantly increased (p < 0.05) blood perfusion and decreased (p < 0.05) distal flap necrosis when compared with sham controls. On the basis of these findings, the authors conclude that in their rat latissimus dorsi muscle flap model the beneficial effects of vascular delay are present as early as 3 days. If these findings also hold true in humans, they could be useful in cardiomyoplasty by allowing surgeons to shorten the amount of time between the vascular delay procedure and the cardiomyoplasty procedure in these very sick patients.     

The value of angiography prior to use of the latissimus dorsi myocutaneous flap.

In 5 patients studied, preoperative angiography showed the thoracodorsal artery to be patent in two--both of them then had successful transfers of latissimus dorsi myocutaneous flaps. Obliteration of this artery was apparent in 3 patients, precluding the operation. We suggest that selective preoperative angiography be performed in all patients in whom a latissimus dorsi myocutaneous flap transfer is being considered, as a patent thoracodorsal artery is essential to the success of this procedure.     

Treatment of chronic radiation injury over the shoulder with a latissimus dorsi myocutaneous flap.

We report our experiences in treating chronic radiation injury about the shoulder, a complication of radiation after mastectomy. Left untreated, these can result in chronic infection and/or amputation. The coverage of a large shoulder area presents certain unique problems, which severely limit the usefulness of traditional procedures. We have found that the remarkable size and versatility of the latissimus dorsi myocutaneous flap enables one to use it with relative simplicity and safety. A further great advantage is that it brings new permanent blood supply into this ischemic area, thus favoring rapid healing and durable coverage.     

Prefabricated sensate myocutaneous and osteomyocutaneous free flaps: an experimental model. Preliminary report

Principles of neovascularization have been reported for the successful creation of a variety of muscle and bone free flaps. This study demonstrates a simple and effective technique for construction of prefabricated sensate myocutaneous and osteomyocutaneous free flaps in a rat model. These experiments were carried out in 20 Sprague-Dawley male rats. In half the animals, a sensate myocutaneous flap was constructed by sandwiching the superficial inferior epigastric vessels between a laterally based external abdominal oblique muscle flap and a laterally based skin flap served by an identified cutaneous nerve. A similar preparation included a piece of iliac crest bone. Two to three weeks later, now neovascularized by the sandwiched vessels, the flaps were harvested and transferred as free flaps with high reliability. An increased number of potential donor sites, the versatility of design, and the ability to customize flaps to the specific recipient-site needs are proffered.     

The pig as an experimental animal in plastic surgery research for the study of skin flaps, myocutaneous flaps and fasciocutaneous flaps

The pig serves as an excellent model of skin flap research. Many flap types are available and flap designs can be modified easily for specific experimental requirements. Swine are large enough to permit multiple flaps and the skin color allows subjective observations of tissue circulation.