Soft tissue reconstruction for the heel and plantar foot.

Soft tissue resurfacing after the ravages of injury or disease continues to be a formidable problem. A thorough understanding of the biomechanics of ambulation and the way in which weight is distributed over the sole of the foot is key to successful outcomes. Soft tissue repair has evolved from the simple filling of holes to a much more sophisticated approach. A plantar-grade foot that distributes the patient's weight in a uniform manner should be the goal. If this can be done without increasing the energy expenditure of ambulation, then surgeons certainly have done our patients an excellent service. Surgeons must not overlook the tendon imbalances and bony deformities that can accompany the effects of disease or trauma. The more complex soft tissue repair may not always be in the patient's best interests. Surgeons should use the simplest approach that can restore the limb to as close to its preinjury level of function as possible. A coordinated approach with plastic surgery, orthopedic surgery, vascular surgery, and podiatric surgery should be the standard of care for patients requiring plantar soft tissue repair.

The role of microsurgical free flaps in foot and ankle surgery.

Microsurgery is clearly an extremely useful adjunct in foot and ankle reconstruction. It requires careful planning between the microsurgeon and vascular, podiatric, and orthopedic surgeons. Ideally, each member of the team should have a special focus on limb salvage. The more experienced the microsurgeon and the better the planning the higher the chance of success. Current success rates in large microsurgical centers exceed 95% free flap survival. Skill in choosing the appropriate flap and optimizing how it is inset ensure an optimal aesthetic and functional result while minimizing the need for later revisions. Adding microsurgical free flaps to the armamentarium of limb salvage surgeons ensures a much higher salvage rate in limbs that heretofore posed too large of a reconstructive challenge and, therefore, were amputated. Current efforts should be directed toward the salvage of only those feet that will be functional, while avoiding limb salvage surgery in other cases. Microsurgical salvage should not be undertaken simply because it is technically feasible. The patient who undergoes 10 to 15 procedures over a 2 to 3 year interval and has a viable, but minimally functional, limb has not been helped. One, therefore, must be sure that the functional salvage can be performed within a defined number of operations in a given time. If not, a below-knee amputation should be considered strongly.

Effect of monophasic blood flow on the patency of microvascular anastomoses.

The effect of monophasic blood flow on the patency of microvascular anastomoses in the rat femoral artery was evaluated by the authors. An experimental model of monophasic blood flow was created in the rat femoral artery to simulate that seen in patients with peripheral vascular disease. Microvascular anastomoses were performed, and the patency at the first hour and 24 hr later was determined. The studies demonstrated that microarterial anastomotic patency was the same when performed in vessels with monophasic or triphasic flow patterns. The authors conclude that monophasic blood flow is not an absolute contraindication for free-tissue transfer.

Isolated cremaster flap: A modified model in intravital microscopy.

Inspection of the microcirculation in living tissues has been accomplished using various models. The rat cremaster muscle has been used for this purpose for more than 20 years. In our study, for the first time, the pedicle of the cremaster muscle has been catheterised indirectly in order to perfuse and drain the muscle and to obtain blood samples. The assessment of the effects of a variety of perfusants on the microcirculation after reperfusion injury can be carried out by using this model.

Reconstruction of the extremity with the dorsal thoracic fascia free flap.

The dorsal thoracic fascia is the anatomic layer that contains the blood supply to the scapular and parascapular fasciocutaneous flaps. The cutaneous vascular territory of the circumflex scapular artery and its parascapular branches is well known. During the past 8 years, the authors have employed the dorsal thoracic fascia free flap for extremity reconstruction in 17 patients (upper extremity, n = 9; lower extremity, n = 8). The indications for using this free flap included primary coverage after trauma (n = 10), resurfacing of "unstable" scar (n = 3), coverage of plantar foot ulceration (n = 3), and coverage of an exposed lower extremity distal arterial bypass graft (n = 1). The large anatomic boundaries of this flap, the consistent vascular anatomy, and the thin yet durable quality of the tissue make this flap an excellent choice for the reconstruction of upper and lower extremity defects.

The effect of pentoxifylline on random-pattern skin-flap necrosis induced by nicotine treatment in the rat.

Cigarette smoke, and specifically nicotine, has been shown to reduce skin-flap survival. The purpose of this study was to determine if the preoperative administration of pentoxifylline can counteract the deleterious effects of nicotine on skin-flap survival in the rat. Sixty rats were distributed into four groups (n = 15). The survival of modified McFarlane skin flaps was assessed on postoperative day 7. The administration of nicotine (0.6 mg/kg) for 24 weeks preoperatively produced an average skin-flap survival of 59 percent; this was significantly decreased compared with controls (p < 0.05). When similarly treated animals were given pentoxifylline (20 mg/kg) for 30 days preoperatively, the mean skin-flap survival improved significantly to 80 percent (p < 0.05). Withholding nicotine for 2 weeks preoperatively also was found to significantly improve skin-flap survival to 73 percent (p < 0.05). Blood filterability was measured as an indicator of viscosity. The blood filterability in rats that received nicotine for 24 weeks was significantly decreased compared with controls (p < 0.05). Both the addition of pentoxifylline preoperatively and the withholding of nicotine for 2 weeks preoperatively were found to significantly improve blood filterability compared with rats that received nicotine alone for 24 weeks postoperatively (p < 0.05).

Reconstruction of breast asymmetry in Poland's chest-wall deformity using microvascular free flaps.

Poland's syndrome comprises a spectrum of chest-wall deformities affecting, to various degrees, the rib cage, the chest-wall muscles, the neurovascular structures of the ipsilateral arm, and the overlying breast. This study details our experience with nine female Poland's syndrome patients who had chest-wall and breast asymmetry corrected by microvascular free-tissue transfer. Nine female patients with Poland's chest deformity underwent 12 microvascular free flaps between 1989 and 1994. Donor sites for free-tissue transfer included eight transverse rectus abdominis flaps, two superior gluteal flaps, one inferior gluteal flap, and one contralateral latissimus dorsi flap. Recipient vessels were branches of the subscapular vascular axis in all patients. Patients' ages ranged from 18 to 47 years at the time of reconstruction. Chest-wall and breast asymmetry varied from accompanying severe pectus and rib cage deformities to isolated breast involvement. Complications were limited to a superior gluteal flap loss due to anomalous subscapular venous drainage. This patient underwent a successful second superior gluteal flap reconstruction utilizing the cephalic venous outflow system. Chest-wall and breast symmetry was restored in all patients. This study demonstrates that microsurgical reconstruction of chest-wall and breast asymmetry in Poland's syndrome yields excellent results with a high degree of patient satisfaction. Careful intraoperative assessment of the recipient vessels prior to flap transfer is mandatory. Because Poland's chest-wall deformity may include anomalies of the vascular system, preoperative vascular assessment with duplex ultrasonography should be considered in all patients, and use of preoperative angiography or venography in selected patients also appears justified.

Microvascular anastomotic thrombosis in experimental diabetes mellitus.

An experimental model was developed to investigate the effects of glycemic control and pentoxifylline administration on microvascular anastomotic patency rates in streptozotocin-induced diabetic rats. Diabetes was confirmed by blood glucose levels of more than 300 mg/dl prior to administering insulin and/or pentoxifylline. Microvascular anastomoses of the femoral artery and vein were performed 4 weeks after induction of diabetes. Subsequently, the comparative rates of anastomotic thrombosis in diabetic and nondiabetic groups with or without insulin or pentoxifylline administration were assessed by direct visualization of the anastomotic sites after 4 days. The results suggest that hyperglycemia impairs the post-operative patency of microvascular venous anastomoses. The diabetic animals maintained under insulin regimens that tightly controlled their serum glucose levels (100 to 200 mg/dl) experienced patency rates similar to those of nondiabetic controls (p < 0.05). Pentoxifylline improved microvenous patency at all levels of hyperglycemia studied, suggesting a possible hemorrheologic mechanism for microvascular venous anastomotic thrombus formation in diabetic animals.

Galeo-pericranial flaps in the forehead: a study of blood supply and volumes.

Despite their extensive use in anterior cranial base reconstruction, very little is understood about the blood supply of galeo-pericranial flaps derived from the forehead region. The goal of this study was to define the extent of the reliable axial blood supply and to determine the volumes of these flaps. The blood supply to anteriorly based galeo-pericranial flaps depends entirely upon the deep branches and a variable component of the superficial branches of the supraorbital and the supratrochlear vessels. The axial component of the blood supply to these flaps is 20-70 mm. The extent of "random' pattern blood supply distal to this could not be adequately assessed. The volumes of various galeo-pericranial flaps range from 3 to 48 cc. The well vascularized proximal portions of galeo-pericranial flaps may well serve the reconstructive needs of the anterior cranial base. Use of more distal portions of these flaps should be undertaken with caution. Some increase in bulk and vascularity may be achieved if the pericranial and the galeal-frontalis myofascial flaps are harvested as a single unit, the composite galeal-frontalis-pericranial flap. Due to the vascular and volume limitations of galeo-pericranial flaps, consideration should be given to the use of microvascular free tissue transfers in instances where large soft tissue defects and a large "dead space' occur.

Quantitative measurement of cutaneous perception in diabetic neuropathy.

To determine the diagnostic value of various cutaneous sensory modalities in diabetic neuropathy, we studied cutaneous perception at the dominant hallux of 113 subjects (32 normal healthy controls and 81 diabetic subjects). The cutaneous sensory perception tests included warm and cold thermal perception, vibration, touch-pressure sensation, and current perception testing (CPT). The sensitivity of each modality when specificity is held greater than 90% was as follows: warm = 78%, cold = 77%, vibration = 88%, tactile-pressure = 77%, 5-Hz CPT = 52%, 250-Hz CPT = 48%, and 2000-Hz CPT = 56%. Combination thermal and vibratory gave optimum sensitivity (92-95%) and specificity (77-86%). We conclude that vibratory and thermal testing should be the primary screening tests for diabetic peripheral neuropathy. Other modalities may be of use only in specific situations.

The accuracy of duplex ultrasonography in the planning of skin flaps in the lower extremity.

The septocutaneous perforators represent one of the major sources of the blood supply to the skin of the lower extremity. Despite several well-described anatomic accounts, the location of lower leg septocutaneous perforators, as they originate from each of the three main infrapopliteal vessels in the leg, remains inconsistent as a result of individual anatomic variations. With the aid of duplex ultrasonography (color Doppler imaging), preoperative, mapping and size determination of these perforators can be provided. The skin paddle can then be designed to lie exactly over these perforators, ensuring blood supply to the skin paddle. The location and distribution of medial septocutaneous perforators in the leg, which originate from the posterior tibial artery, were mapped using anatomic dissections (29 lower extremities). These findings were then compared with duplex ultrasonographic data in 9 living volunteers (18 lower extremities). The medial septocutaneous perforators were chosen for this study because they course directly over the posterior tibial artery, making their location difficult to assess with standard Doppler techniques. The hand-held Doppler is incapable of distinguishing flow originating from the perforators versus the posterior tibial artery. No significant difference existed between cadaver and duplex distributions. "Large" perforator vessels (> 1 mm outer diameter) were evenly distributed with a central tendency at 140 to 150 mm from the medial malleolus. The distribution of "small" perforator vessels (< 1 mm outer diameter) was skewed. Fifty percent were found within 80 mm of the medial malleolus and the remainder spread proximally in the leg.(ABSTRACT TRUNCATED AT 250 WORDS)

The gastrocnemius muscle as a free-flap donor site.

Despite the fact that the pedicled gastrocnemius flap has been used clinically for almost two decades, precise data on its neurovascular anatomy are lacking. A detailed knowledge of the neurovascular anatomy of this flap may encourage its more extensive use as a donor site by the means of microvascular free-tissue transfer. The femoral or popliteal artery in 27 fresh cadavers was injected with radiopaque contrast material to study the gross vascular supply of 54 medical and 50 lateral gastrocnemius muscles. The intramuscular vascular anatomy also was analyzed in 29 medial and 24 lateral gastrocnemius muscles using x-ray technique. Depending on the number of the sural arteries that supply the gastrocnemius muscle, flaps were classified as type 1 or type 2. Type 1 muscle bellies (lateral or medial gastrocnemius muscle belly) are supplied by one sural artery, while in type 2 muscles two arteries supply one muscle belly. Eighty-five percent of medial and 84 percent of lateral gastrocnemius muscle bellies had single vascular pedicles (type 1). The point of origin of the sural artery(s) permitted us to further classify the blood supply to the muscle bellies as subtypes A, B, and C. Intramuscular vascular anatomy is characterized as either a single vessel (dominant type) or two vessels (nondominant type). A single motor nerve, from the tibial nerve, accompanied the primary vascular pedicle into each muscle belly. When there were two vascular pedicles supplying one muscle belly, only one motor nerve accompanied the major pedicle.(ABSTRACT TRUNCATED AT 250 WORDS)

Soft tissue reconstruction. Coverage of lower leg. Rotational flap.

The combined orthopedic and plastic surgical approach to the injured lower extremity has permitted successful salvage of otherwise severely injured limbs. Although numerous muscle and fascial flaps have been described for all regions of the leg between the knee and foot, specific treatment regimens have become popular based on the location of the wound. Refinements in flap surgery have permitted the approach discussed in this article to become standard in the care of patients with either chronic osteomyelitis or acutely injured limbs. This article delineates the muscle and fascial flaps that are used to reconstruct these defects.

Diabetic neuropathies.

Diabetic neuropathy is a common complication of diabetes that may be associated both with considerable morbidity (painful polyneuropathy, neuropathic ulceration) and mortality (autonomic neuropathy). The epidemiology and natural history of diabetic neuropathy is clouded with uncertainty, largely caused by confusion in the definition and measurement of this disorder. We have reviewed various clinical manifestations associated with somatic and autonomic neuropathy, and we herein discuss current views related to the management of the various abnormalities. Although unproven, the best evidence suggests that near-normal control of blood glucose in the early years after diabetes onset may help delay the development of clinically significant nerve impairment. Intensive therapy to achieve normalization of blood glucose also may lead to reversibility of early diabetic neuropathy, but again, this is unproven. Our ability to manage successfully the many different manifestations of diabetic neuropathy depends ultimately on our success in uncovering the pathogenic processes underlying this disorder. The recent resurgence of interest in the vascular hypothesis, for example, has opened up new avenues of investigation for therapeutic intervention. Paralleling our increased understanding of the pathogenesis of diabetic neuropathy, refinements must be made in our ability to measure quantitatively the different types of defects that occur in this disorder. These tests must be validated and standardized to allow comparability between studies and more meaningful interpretation of study results.

Free flaps in the elderly.

Microsurgical transfer of tissue has become a primary tool of the reconstructive surgeon. The elderly, as a growing segment of our society, are requiring free-tissue transfers in proportion to their numbers. To investigate the potential morbidity of free-tissue transfers in the elderly, we studied consecutive populations of 31 patients above the age of 65 years and 90 patients below the age of 65 years. Complication rates were 65 and 49 percent, respectively. Premorbid medical conditions were present in 87 percent of patients 65 years and older and in 72 percent of those under 65 years. Medically related complications in free-tissue transfers, previously unreported in the literature, were 35 percent in the elderly group and 10 percent in the younger group. Wound-healing complications were seen in equal proportions between groups. The rates of wound and medically related complications observed in the elderly group were nearly double those observed in the younger group; however, after correction for the presence of preexisting medical conditions, no significant differences were seen between the two groups. These observations suggest that age alone is not a variable in risk for free-tissue transfers. Elective microsurgery can be performed in the elderly patient with a high expectation of success.

Vascular resistance considerations in free-tissue transfer.

The closure of complex wounds is facilitated by microvascular free-tissue transfer. The greatest threat to the success of a free-tissue transfer is thrombosis of the microvascular anastomosis. Technical and pharmacologic advances have decreased the thrombogenic effect of abnormalities of a vessel's endothelial lining, and have decreased the coagulation ability of blood. Equally important to patency of the microvascular anastomosis is blood flow, which is inversely proportional to the total resistance provided by the microcirculatory beds downstream. Because different tissues possess different vascular resistances, some flaps may display more favorable hemodynamics than others. This study was designed to characterize vascular resistance, weight, volume, and surface area of the flaps available for transfer, and to identify favorable tissues for reconstruction from the standpoint of outflow resistances. Data were collected on patients undergoing free-tissue transfers and on experimental free-tissue transfers harvested from canines and fresh cadavers. Results show that resistance is highest in fascial flaps, intermediate in composite bone and soft-tissue flaps, and lowest in muscle and musculocutaneous tissues. Resistance is lower in flaps harvested from the trunk, compared with those harvested from the extremities. The rate of microvascular complications increases as resistance within the flap increases. Muscle and musculocutaneous flaps harvested from the trunk have lower complication rates than fascial and fasciocutaneous flaps. Suggestions for choices of flaps are made, based on the inherent resistance in the various free flap tissues.

Tobacco smoking and complications in elective microsurgery.

This study assesses the risk for complications in patients who chronically smoke but who have quit in the perioperative period of an elective free-tissue transfer as compared with patients who do not smoke. A retrospective review identified 104 free-tissue transfers in 93 smokers and 58 transfers in 51 nonsmokers. The demographics, wound etiology, and recipient sites were similar in the two populations. With the exception of a higher incidence of chronic obstructive pulmonary disease (COPD) among smokers, preexisting comorbid factors also were similar. Postoperative medical complications were comparable between populations. When comparing smokers with nonsmokers, we found that anastomotic patency and flap survival were not different (95 versus 94 percent, respectively), that delayed wound healing at the recipient site was different (35 versus 24 percent), and that smokers require an additional procedure to achieve final wound closure more frequently (27 versus 12 percent, p = 0.03). These findings suggest that cigarette smokers are at increased risk for complications, not at the site of the anastomosis in free-tissue transfer, but rather at the flap's interface with the wound or overlying skin graft.