Cultured human sole-derived keratinocyte grafts re-express site-specific differentiation after transplantation.

Cultured epithelial autografts (CEA) derived from sole skin were transplanted to full-thickness wounds excised to muscle fascia over a variety of diverse body sites in 12 pediatric patients treated for acute burns or giant congenital nevi. The skin regenerated from the grafts was biopsied from 7 days to 6 years after grafting. The resultant epidermal phenotype was analyzed histologically and by immunohistochemical localization of keratin 9 (K9) as objective evidence of sole-type site-specific differentiation. Expression of K9 was also verified by one-dimensional gel electrophoresis of epidermal cytoskeletal extracts and K9 immunoblot analysis. Grafts prepared from epidermis of axilla; groin or foreskin and transplanted to wounds of comparable depth in an identical manner in the same patients served as controls of postgrafting differentiation. Biopsies of sole skin from amputation specimens from patients of comparable age served as normal positive controls, and biopsies of nonsole skin from patients of comparable age served as normal negative controls. As early as 2 weeks postgrafting, the histologic appearance of sole-derived CEA differed substantively from that of axilla- or groin-derived CEA controls and displayed a phenotype characteristic of sole skin with a thick compact stratum corneum, a thick stratum granulosum, and a distinct stratum lucidum. In sole-derived grafts rete ridges regenerated within 2 months postgrafting, whereas nonsole-derived grafts required 4-6 months for rete ridge regeneration. Once acquired, the sole skin phenotype was maintained long-term by all sole-derived CEA. In vitro, sole-derived keratinocytes synthesized little, if any, K9. However, within 7 days after grafting, K9 synthesis by multiple suprabasal keratinocytes was seen within the epidermis regenerated from sole-derived CEA. Protein of K9 appeared progressively more diffuse throughout the suprabasal layers, attaining a confluent pattern of expression comparable to normal controls of sole skin by 6 to 12 months postgrafting, and the confluent pattern of suprabasal K9 synthesis was maintained long-term. The results demonstrate that site-specific differentiation is an intrinsic property of postnatal human keratinocytes and can be expressed and maintained in a permissive environment in the absence of dermal tissue.

Engineering a skin replacement.

Major skin loss from trauma or burns cannot always be replaced with the patient's own skin. An engineered skin replacement would restore the barrier function of the skin, remain permanently on the wound, and minimize late functional complications of wound contraction. Cultured epithelial autograft (CEA) sheets reproduce the epidermis' function and have been used in burn patients to close large wounds. There are several promising avenues for dermal replacement, but none has yet had wide clinical application.

A socioeconomic analysis of digital replantations resulting from home use of power tools.

Forty-seven digits in 21 patients who sustained partial or complete amputations from the home use of power tools were replanted or revascularized during a 1-year period. This represented 69% of the microvascular surgery performed for hand injuries during that year. The cost of repairing an average of 2.4 digits was $7000 (surgeon's fee) plus $697 per hour (operating room fee), as per fiscal year 1987. Postoperative hospitalization averaged 15 days at a cost of $15,679. Hand rehabilitation averaged 8 months at a cost of $3348. Fifty-four percent of the patients had no insurance. Fourteen of 21 patients (67%) required at least one additional procedure. Two patients had to make a career change after the injury. The majority of patients with digital replantations were dissatisfied with the emotional costs and the number of subsequent operations. Lack of patient and family awareness of the length of the rehabilitative period was particularly evident.

Familial bilateral carpal tunnel syndrome: report of two families.

Cases of familial carpal tunnel syndrome without other associated conditions are rare. We report two families in which multiple members had bilateral carpal tunnel syndromes. The pattern was consistent with autosomal dominant inheritance. Electrophysiologic studies were performed on nine of the 15 patients, and they demonstrated bilateral pathology of the median nerves at the wrist in all but one patient, without evidence for subclinical, generalized peripheral neuropathy. Quantitative sensory testing was performed in two cases, and it corroborated the absence of peripheral neuropathy. Five of the six patients who underwent carpal tunnel release improved after surgery.

Treatment of chronic traumatic bone wounds. Microvascular free tissue transfer: a 13-year experience in 96 patients.

During a 13-year period at the Massachusetts General Hospital, Boston, Massachusetts, 97 microvascular free tissue transfers have been performed for soft-tissue reconstruction in 96 patients following bone debridement for chronic traumatic bone wounds. These 96 patients comprise a continuation study of 18 original patients reported in 1982. During a 13-year follow-up period (mean, 77.1 months), 95.8% of these 96 patients have enjoyed complete wound closure with a lack of drainage after the debridement and free tissue transfer. Most of the patients (89.6%) encountered in this study are ambulatory without assist and 5.2% of patients have undergone amputation. Twenty-three per cent of patients required subsequent segmental bone defect reconstruction in the lower extremity after infection eradication. The pathophysiology of chronic traumatic bony wounds is different from that of chronic hematogenous osteomyelitis and thus a high incidence of long-term successful management can be seen through complete wound debridement and adequate soft-tissue coverage.

Biologic skin substitutes.

The absence or loss of skin, because of the resulting drain of fluids and protein and because of the risk of invasive infection, requires wound closure with a skin substitute. Split-thickness skin graft is the gold standard for skin substitutes. Human cadaver allografts are the ideal temporary skin substitute, and their life can be prolonged by immunosuppression in the recipient. The potential for transmission of human immunodeficiency virus infections from these grafts limits their use. Epidermis can be replaced with tissue-cultured autogenous keratinocyte sheets. Several groups have used these grafts in patients successfully. Recent evidence indicates that the new epidermis directs the differentiation of the subjacent collagen tissue into an architecture resembling a papillary and reticular dermis. Several methods are being evaluated for the direct replacement of the dermis, including cadaver dermis, collagen-GAG matrices, and fibroblast-impregnated collagen gels. Clinically useful advances in skin substitutes have been made in the last decade, and these advances will lead to the answer to the problem of missing skin.

Cultured epithelial autografts for giant congenital nevi.

Eight pediatric patients with giant congenital nevi confluent over 21 to 51 percent body surface area were treated by excision and grafting. The nevus was excised to the muscle fascia, and the open wound was grafted with cultured epithelial autografts and split-thickness skin grafts. The patients have been followed from 17 to 56 months. Seventeen operations were performed in the eight patients, excising a mean of 6.9 percent body surface area at each procedure. The mean duration of anesthesia was 3.7 hours, and the mean operative blood loss was 12.3 percent estimated blood volume. The mean "take" for the cultured epithelial autografts was 68 percent, and for the split-thickness skin grafts, 84 percent. Epithelialization of open wound areas adjacent to the grafts was somewhat slower for the cultured epithelial autografts than for the split-thickness skin grafts, but it led to a healed wound in all patients except one. Ten of the 17 areas grafted with cultured epithelial autografts resulted in small open wounds that required regrafting. Wound contraction under the cultured epithelial autografts and under split-thickness skin grafts was similar and depended more on the anatomic site grafted than on the type of graft employed. in 16 of 17 operations, the cultured epithelium remained as a permanent, durable skin coverage. The use of cultured epithelial autografts allowed a larger area of excision than would have been possible with split-thickness skin grafts alone and, therefore, a more rapid removal of nevus. Cultured epithelial autograft are an important new technique in the care of patients with giant congenital nevi.

Skin regenerated from cultured epithelial autografts on full-thickness burn wounds from 6 days to 5 years after grafting. A light, electron microscopic and immunohistochemical study.

Regeneration of skin from cultured keratinocyte autografts used in the treatment of full-thickness burn wounds was studied in 21 pediatric patients from 6 days to 5 years after grafting. Findings were compared both to controls of age- and site-matched normal skin and to controls for epithelial wound-healing, re-epithelialized interstices of meshed split-thickness skin grafts of comparable postgrafting age. Six days after transplantation, a mildly hypertrophic, flat epidermis with all normal strata had regenerated, and the process of de novo dermal-epidermal junction formation had begun. Hemidesmosomes, basal lamina, and anchoring fibrils reformed conjointly in punctate fashion along the attachment face of the grafts. Within 3 to 4 weeks, the dermal-epidermal junction was complete, but full maturation of anchoring fibrils required more than a year. The process was comparable to that observed in meshed graft interstices. Rete ridges regenerated from 6 weeks to 1 year after grafting. The subjacent connective tissue initially healed to form normal scar, but it remodeled dramatically, regenerated elastin, and resembled a true dermis within 4 to 5 years. Meshed-graft interstice controls showed no rete ridge regeneration, subepithelial connective tissue remodeling, or elastin production up to 5 years after grafting. Langerhans cells repopulated grafts within 1 week, and normal population densities were reached within 2 to 6 months. After 1 year, Langerhans cell densities were increased compared with normal skin but were lower than those in age-matched meshed graft controls. Melanocytes were present in cultures at the time of transplantation, but functional epidermal melanin units were not seen in groin- or axilla-derived grafts for 6 to 8 weeks or in sole-derived epidermis until a year or more after transplantation. Normal histologic features were maintained for years after grafting. Transitory pathologic changes including parakeratosis, dyskeratosis, and intraepithelial friction blister formation were infrequently observed. No dysplastic or premalignant changes were seen.

The role of external fixation in the treatment of posttraumatic osteomyelitis.

External skeletal fixation played a central role in the reconstruction of 30 limbs involved in posttraumatic osteomyelitis. The tibia was involved in 15, the femur in six, the ankle in five, and the foot and radius in two each. Of the thirty limbs, 27 were ununited. Positive bacteriology and/or histology was found in each case. A total of 36 frames were used with 20 unilateral half-frame constructs and 16 bilateral transfixion frames. The average duration of external fixation was 60 days. Specific procedures for soft tissue coverage were required in 21 cases and autogenous bone grafting in 26. Loosening and local infection occurred in three of 168 external fixation pins. There were no cases of pin-track osteomyelitis, fractures through pintracks, or neurovascular damage from pin insertion. Infection was controlled in 29 of 30 limbs, with one requiring a below-knee amputation. Skeletal union was achieved in all cases. At an average follow-up of 35 months, 20 of 28 lower limbs in 27 patients tolerated full weight bearing without ambulatory aides. Four used a patellar tendon-bearing polypropylene orthosis, two used a cane, and one a walker. In the 23 patients ambulating without upper-extremity aides, the average time from the start of treatment to reach this functional status was 14 months.

Free flaps to preserve below-knee amputation stumps: long-term evaluation.

Five patients with insufficient soft-tissue coverage on below-knee amputation stumps have been treated with free-tissue transfer surgery to preserve a functional below-knee prosthetic level. The flaps employed include one latissimus dorsi myocutaneous flap, two latissimus dorsi muscle-skin graft flaps, one groin flap, and one foot-fillet flap. All five flaps survived; one patient required early venous anastomosis reexploration and revision. The patients have been followed for a mean duration of 5.5 years (range 3 to 8 years). The mean duration to first ambulation with a prosthesis was 3.6 months (range 2 to 7 months). Four of the five patients developed ulcerations on or adjacent to their flaps which required surgical revision. The patients required a mean of 1.28 prosthesis changes annually since surgery. The functional motion (mean active knee motion is 100 degrees) and ligamentous stability of the knee joints were well preserved in all patients. Five patients wear patella tendon-bearing prostheses, with one requiring an additional thigh corset. In two of the patients, nerve anastomoses to their flaps were performed. Both patients developed true cutaneous sensibility, but nevertheless experienced flap ulceration. All the patients are fully ambulatory on their free flaps. Free-tissue transfer can assist in preserving traumatic below-knee amputations so that patients can benefit from the functional advantage of a below-knee prosthetic device.

Cultured epithelium as a skin substitute.

The history of techniques for the replacement of lost skin is reviewed, including the current research in the use of synthetic dermal substitutes, skin allografts and immunosuppression, and tissue-cultured epithelial autografts. Developments in each of these three areas are encouraging steps toward the development of a skin substitute that would be immediately available for coverage of even massive areas of skin loss.

Free latissimus dorsi muscle flap with skin graft for treatment of traumatic chronic bony wounds.

Based on this review of 35 cases of chronic bony wounds, it would appear that the free-muscle flap method of wound closure and nourishment after thorough dead bone debridement is an attractive and successful alternative to local skin flaps, staged skin flaps, or extend skin-muscle flaps in areas where reliable muscle flaps are not available. It would also seem that the latissimus dorsi muscle flap with skin graft is an ideal donor-muscle transfer with features allowing a favorable and contoured surface in the recipient site and minimal aesthetic and functional deformity in the donor site.

Removable thermocouple probe microvascular patency monitor: an experimental and clinical study.

Based upon experimental animal evaluation and a preliminary clinical experience in 18 patients with 3 recognized failing flaps, the implantable thermocouple probe microvascular method of vessel patency assessment would appear to be a promising new technique worthy of further clinical investigation.

Limb salvage by extended profundaplasty of occluded deep femoral arteries.

This report presents our experience with extended profundaplasty as an outflow procedure for limb salvage in patients with occluded common and profunda femoris arteries. During a 5 year period at Salem Hospital, 15 limbs in 11 patients were revascularized by a variety of inflow procedures combined with extended endarterectomy and patch grafting of an occluded profunda femoris artery. All patients presented with rest pain, ischemic ulcers, or gangrenous toes. Patients with acute embolic disease or thrombosis of a limb of a graft which required immediate reconstruction were excluded from this study. Preoperative arteriograms revealed no patent femoral or graftable popliteal vessels but did demonstrate collateral circulation, specifically portions of the circumflex femoral arteries and muscular branches of the profunda. Operation was undertaken to disobliterate the profunda and reinstitute direct perfusion of the collateral bed. In all cases it was possible to endarterectomize the profunda to eliminate distal spared vessel and to open most of the profunda branches. There was no operative mortality. Follow-up revealed 87 percent limb salvage and 80 percent patency at 1 year. At 2.5 years limb salvage was 77 percent and reconstruction has remained patent in 60 percent of the limbs. These results compare favorably with series that have reported reconstructions for profunda stenosis alone. These preliminary data suggest that endarterectomy and long patch grafting of the proximally occluded profunda may have merit in providing worthwhile palliation in a small subset of patients with advanced occlusive disease.

Extremity replantation.

Replantation surgery has progressed in 20 years from a laboratory curiosity to a common and useful clinical procedure. All patients with partial or complete amputations should be considered for replantation of the part. However, only a number of these patients are appropriate for replantation. The indications for replantation should not be based only on the potential viability of the limb, but, more important, should be based on the potential function of the replanted part. The function is related to the level of the amputation, to the mechanism of the amputation, and to the age and motivation of the patient. Replantation surgery requires technical competence and clinical acumen. Surgeons performing replantations should maintain their microvascular technique in laboratory work and elective microsurgical procedures. Because the operations are quite arduous and require teams of surgeons relieving each other and because assessment of the appropriateness of replantation requires considerable clinical experience, replantation operations are best performed by teams in large medical centers.

Microvascular transfer of free tissue for closure of bone wounds of the distal lower extremity.

Extensive compound fractures of the distal lower extremity may result in chronic infection of the deep tissues and bone if primary healing does not occur. Treatment may require several operations and prolonged hospitalization. In an attempt to improve the management of such problems, 18 patients who had chronic bone-exposure wounds and four patients who had extensive compound fracture wounds of the distal lower extremity were treated with radical debridement, intravenous antibiotics, and microvascular transfer of vascularized tissues for immediate wound closure. All wounds healed, and there was no evidence of recurrent infection during a mean follow-up period of 19.3 months in the patients with chronic wounds and 16.3 months in those with acute wounds. In selected patients this free-tissue-transfer method of wound closure appears to have considerable advantages over conventional methods of management.

Latissimus dorsi free muscle flap in lower-extremity reconstruction.

The free latissimus dorsi skin-muscle flap has gained wide popularity to solve a variety of difficult reconstructive surgical problems. However, the donor site of this skin-muscle flap leaves a conspicuous scar and indentation, and frequently in the recipient site the skin-muscle flap leaves a conspicuous scar and indentation, and frequently in the recipient site the skin-muscle flap requires staged defatting procedures. This case demonstrates the use of the latissimus dorsi muscle flap for lower-extremity reconstruction, where a new blood supply and soft-tissue coverage are required to solve a chronically infected, open ankle joint. By taking the latissimus muscle only through a short, axillary incision, much of the donor-site deformity is minimized, and after transfer, the muscle can be molded and shaped to fit the recipient site with split-thickness skin graft coverage. This combination of free muscle flap transfer and skin graft would appear to provide a flexible, contoured, well-vascularized muscle with a relatively inconspicuous incision and skin-graft donor site.