Achievements and challenges in composite tissue allotransplantation.

Overall, more than 60 hand/forearm/arm transplantations and 16 face transplantations have been performed in the past 12 years. In the European experience summarized here, three grafts have been lost in response to a vascular thrombosis (n = 1), rejection and incompliance with immunosuppression (n = 1) and death (n = 1). The overall functional and esthetic outcome is very satisfactory, but serious side effects and complications related to immunosuppression are challenges hindering progress in this field. The high levels of immunosuppression, skin rejection, nerve regeneration, donor legislation and the acceptance level need to be addressed to promote growth of this promising new field in transplantation and reconstructive surgery.

Complete middle forearm amputations after avulsion injuries--microsurgical replantation results in Vietnamese patients.

BACKGROUND: Replantation after complete avulsion amputations at the level of the middle forearm is rarely reported in the literature and remains one of the most difficult challenges for microsurgeons. Microsurgery and its clinical applications are new procedures in Vietnam. The purpose of this article is to evaluate our replantation results in Vietnamese patients relating to this type of injury using microsurgical techniques. METHODS: Ten replanted patients after complete avulsion amputations of the middle forearm, operated on at the Department of Trauma and Orthopedics in the Central University Hospital 108 in Hanoi, Vietnam during a 7-year period (between September 1999 and April 2006) were reviewed and subsequently evaluated. All patient information was reexamined and documented. RESULTS: All replants had survived. All cases of bone stabilization using plates and screws (3 of 10 cases) were postoperatively infected and required supplemental intervention with flap reconstructions, whereas this was not observed in seven other patients receiving Kirschner wires (KW) combined with cerclages. Replantation was performed in a patient associated with plexus brachialis paralysis of the affected limb, which was not detected before the procedure. The combined postoperative functional outcomes rated from "excellent" to "fair" in 70% of cases based on an average follow-up period of 20 months. CONCLUSION: With respect to social and psychologic effects, performance of the procedure is extremely worthwhile because it not only provides complete limb preservation, but also has excellent potential for a favorable functional outcome.

Comparison of effective use of implanted vascular pedicles for skin flap prefabrication: an experimental study.

Thin, large, well-vascularized, and axial-pattern flaps are often desired in the clinical practice of defect reconstruction to maximize esthetic and functional results. Flap prefabrication based on the neovascularization development following vascular pedicle implantation allows surgeons to create such flaps as required. Using different types of implanted vascular pedicles, the aim of the study was to identify the most effective and suitable types of pedicles for clinical use. Five models of implanted vascular pedicles in Chinchilla Bastard rabbits were investigated as follows: model 1, arteriovenous (AV) pedicle with end ligation (minimal blood flow in the implanted vascular pedicle); model 2, AV pedicle with end anastomosis (new shunt formation between vein and artery stump for creating maximal blood flow in the implanted vascular pedicle); model 3, purely isolated arterialized venous loop; model 4, purely isolated arterial loop; model 5, AV pedicle with end anastomosis (similar to model 2) combined with flap expansion. These different types of vascular pedicles were implanted into a random-pattern abdominal skin flap as large as 8 x 15 cm. Neovascularization in the various prefabricated flaps was evaluated macroscopically, scintigraphically, microangiographically, and histologically. A total of 150 prefabricated flaps were investigated and randomly assigned to 5 models with 30 flaps each. Each model contained 5 groups of 6 flaps corresponding to the various retention times of 4, 8, 12, 16, and 20 days after vascular pedicle implantation. Six flaps were also designated to the control group. Neovascularization was best in model 5, followed by comparable results for models 2, 3, and 4, with the worst results found in model 1, especially for the time intervals of 8, 12, and 16 days. Twenty days remains the minimal length of time required for matured neovascularization in all models (P < 0.05). Models 2 and 3 both appear to be particularly promising for clinical application.

Effectiveness of free gracilis muscle flaps in the treatment of chronic osteomyelitis with purulent fistulas at the distal third of the tibia in children.

BACKGROUND: Chronic purulent infection at the distal third of the tibia resulting from of a previous hematogenous osteomyelitis in children is a severe infection which is seldom reported in the literature and remains a difficult challenge for orthopaedic surgeons. METHODS: A 6-year retrospective review from September 2001 to October 2006 (institutional review board-approved) was performed to evaluate postoperative surgical results of this type of infection using a free gracilis muscle flap. RESULTS: A total of 6 children with an average age of 9.8 years were included. The infective period of purulent fistulas ranged from 6 to 31 months (mean 17.7). Staphylococcus aureus were reported in all wounds (6/6) and were commonly combined with Escherichia coli (5/6). All of the free gracilis muscle transfers were successful (6/6 flaps). No postoperative recurrence of infection was observed with an average postoperative follow-up period of 3 years. All patients were also able to satisfactorily demonstrate walking and standing functions. CONCLUSIONS: Both the radical debridement of infected tissues and restoration of ample blood supply using free muscle flaps are the keys to success. Based on its favorable form, the free gracilis muscle flap can be considered a suitable muscle for use in reconstruction. LEVEL OF EVIDENCE: IV.

Neovascularization and free microsurgical transfer of in vitro cartilage-engineered constructs.

Cartilage tissue engineering shows to have tremendous potential for the reconstruction of three-dimensional cartilage defects. To ensure survival, shape, and function, in vitro cartilage-engineered constructs must be revascularized. This article presents an effective method for neovascularization and free microsurgical transfer of these in vitro constructs. Twelve female Chinchilla Bastard rabbits were used. Cartilage-engineered constructs were created by isolating chondrocytes from auricular biopsies, amplifying in monolayer culture, and then seeding them onto polycaprolactone scaffolds. In each prefabricated skin flap, three in vitro cartilage-engineered constructs (2 x 2 x 0.5 cm) and one construct without cells (served as the control) were implanted beneath an 8 x 15 cm random-pattern skin flap, neovascularized by implantation of an arteriovenous vascular pedicle with maximal blood flow. Six weeks later, the neovascularized flaps with embedded cartilage-engineered constructs were completely removed based on the newly implanted vascular pedicle, and then freely retransferred into position using microsurgery. Macroscopic observation, selective microangiography, histology, and immunohistochemistry were performed to determine the construct vitality, neovascularization, and new cartilage formation. The results showed that all neovascularized skin flaps with embedded constructs were successfully free-transferred as free flaps. The implanted constructs were well integrated and protected within the flap. All constructs were well neovascularized and showed histologically stability in both size and form. Immunohistology showed the existence of cartilage-like tissue with extracellular matrix neosynthesis.

Influence of silicone sheets on microvascular anastomosis.

The use of silicone products combined with free flap transfer is well established in reconstructive surgery. We determined the risk of thrombosis as a result of direct contact between the silicone sheet and the point of microanastomosis. We performed microvascular surgery in 24 female Chinchilla Bastard rabbits weighing 3500 to 4000 g using two groups: Group 1 (n = 12), microanastomosis directly in contact with silicone sheets; and Group 2 (n = 12), microanastomosis protected by a 2 x 3 x 1-cm muscle cuff before being placed in contact with the silicone. We assessed flow-through of the microanastomosis by selective microangiography and histology at 1 and 3 weeks. All microanastomoses in Group 1 were occluded by postoperative thromboses, whereas all microanastomoses in Group 2 had adequate flow-through. Histologic analysis revealed thromboses in Group 1 formed from collagenous bundles of fiber securely attached to the intraluminal wall of the vessel. Three weeks after the procedure, these thromboses were canalized by varying small vessels. In Group 2, a slight luminal stenosis with evidence of infiltration of inflammatory cells at the microanastomosis line was observed histologically in all cases. Prefabricated flaps using silicone sheets and muscular cuffs placed around the anastomoses appear to reduce the risk of thrombosis and enhance neovascularization.

Successful re-construction of a large tissue defect using a free pre-fabricated flap with purely implanted arterialised venous loop.

Flap pre-fabrication represents an interesting technique in tissue-defect reconstruction. In this article we report the successful clinical application of a free pre-fabricated flap using an isolated arterialised venous loop as an implanted vascular pedicle for reconstruction of an extended soft-tissue defect on the leg, as well as clinical neo-vascularisation development following arterialised venous loop implantation. The procedure appears potentially useful in selected patients due to the easy harvest of an isolated vein loop as well as a favourable functional and aesthetic result at the donor site.