Seok Chan Eun

Analysis of multiple risk factors affecting the result of free flap transfer for necrotising soft tissue defects of the lower extremities in patients with type 2 diabetes mellitus

BACKGROUNDnThe limb-threatening large soft tissue defects that occur on the feet of type 2 diabetic patients have complex causes and are less likely to be corrected by free flap reconstruction compared to those in non-diabetic patients. We retrospectively analysed factors affecting the success of free flap transfer for necrotising soft tissue defects of the lower extremities in patients with type 2 diabetes.nnnMETHODSnThis study included 33 diabetic patients whose feet were treated with free flap transfers. All patients had limb-threatening large soft tissue defects with tendon or bone exposure. The operative results were divided into three groups at 1 month post-operatively: the complete healing group, and the complication group, with either partial necrosis requiring additional simple procedures or flap failure with total necrosis. Nine preoperative factors were analysed: (1) ankle brachial index, (2) HbA1c, (3) BMI, (4) the smoking factor, (5) atherosclerotic calcifications (6) serum creatinine levels (>1.28 mg dL(-1) vs. <1.28 mg dL(-1)), (7) GFR, (8) wound infection and (9) wound defect size.nnnRESULTSnOf the 33 patients, 15 showed complete healing and 18 showed complications of the free flap (eight partial necrosis and 10 flap failure). No atherosclerotic calcifications were found in the patients in the complete healing group, although they were found in 12 patients in the complication group, and this difference was significant (p = 0.002). Patients with serum creatinine levels >1.28 mg dL(-1) had significantly higher free flap transfer complication rates than those with serum creatinine levels <1.28 mg dL(-1) (p = 0.038).nnnCONCLUSIONSnThis study analysed the risk factors of free flap reconstruction for limb-threatening large soft tissue defects on the feet of type 2 diabetic patients. Serum creatinine levels >1.28 mg dL(-1) and atherosclerotic calcifications were confirmed as risk factors for flap survival.

Composite Tissue Allotransplantation Immunology

Composite tissue allotransplantation (CTA) is an option recently introduced for major reconstruction of tissue defects. Since announcements of successful hand, larynx, knee, muscle, nerve, abdominal wall and, most recently, partial face transplantation, CTA has become one of the techniques used by plastic and reconstructive surgeons [1]. Clinical success in CTA is the culmination of progress in two disparate surgical disciplines: replantation and organ transplantation, a close collaboration between plastic and transplant surgeons. This joining of reconstructive and transplant surgery forces the movement of hand and facial tissue allotransplantation into the clinical arena [2]. Translation to the clinical field has shown that CTA is a viable treatment option for those who have lost extremities and suffered large tissue defects [3-5]. n nAs with other allografts, CTA can undergo immune-mediated rejection. When compared with solid organ transplants, composite tissue allografts are histologically heterogeneous, composed of different tissue types (e.g., skin, muscle, bone, bone marrow, lymph nodes, nerve, and tendon), and express different immunogenicity of transplanted elements [6]. Currently, the most important issue for routine application of CTA to clinical practice is the need for lifelong immunosuppression [7]. The immunosuppression medications used to prevent tissue rejection in CTA are the same as those used in tens of thousands of solid organ transplant recipients. The toxicity of chronic, nonspecific immunosuppression remains a major limitation to the widespread availability of CTA and is associated with opportunistic infections, nephrotoxicity, end-organ damage, and an increased rate of malignancy [6]. Because composite tissue allograft transplantations are not life-saving procedures, much attention has been devoted to the issue of minimizing or withdrawing immunosuppression, and this would represent a significant step forward in this field [8]. Over the past five to six decades, advances in the field of transplant immunology have transformed solid organ transplantation into standard care, with excellent short term results in kidney, heart, lung, liver, and pancreas transplantation. The science of CTA is rooted in progressive thinking and the innovative solutions of plastic surgeons. Development of a tolerance regimen or new less toxic immunosuppressive protocols is essential for future acceptance of CTA [9]. With cautious optimism and healthy critiques, the science of CTA promises a bright future. This paper reviews key terminology, drug combinations, mechanisms of immunosuppression, the risks associated with CTA, and immune tolerance protocols.

Facial transplantation surgery.

It is well known that patients with severe facial injuries accompanied by facial disfiguration are vulnerable to a poor quality of life. With the help of facial transplantation, it has become possible to achieve an optimal anatomical reconstruction. As compared to conventional methods, it can provide more desirable functional, aesthetic, and psychosocial outcomes. Face transplantation surgeons need to consider many problems associated with the criteria for selecting patients, techniques for harvesting the donor tissue, prediction of the expected functional outcomes, limitations in obtaining written informed consent for conducting the procedure, evaluation of the post-transplant immunological response and postoperative immunosuppressant requirements, psychological and social outcomes for the patients, and other concerns about funding and ethical issues.

The effects of mega-dose ascorbic acid on skin flap survival: experimental study on rats.

POD: postoperative day. a p< 0.01 by KruskaleWallis test. b p Z 0.002 compared to Control group by t-test and ManneWhitney test. c p< 0.01 compared to Control group. d p< 0.01 compared to Group-Vit. C 200 mg. e p< 0.01 compared to Group-Vit. C 500 mg. f One has expired at the 2nd postoperative day. The purpose of this study was to determine the effects of dose-related ascorbic acid on the random skin flap in an experimental rat model. We used w300e350-g SpragueeDawley (SD) rats raised under the same condition, regardless of sex. The 40 rats were divided into a control group (n Z 10) to which ascorbic acid was not administered, a group (n Z 10) to which 200 mg of ascorbic acid (Cantan , 2 ml Z 1000 mg, Handok Pharmaceuticals Co., Ltd., Korea) was administered through a hypodermic injection, a group (n Z 10) to which 500 mg of ascorbic acid was administered and a group (n Z 10) to which 1000 mg of ascorbic acid was administered. In all the groups, anaesthesia was attained by injecting 50 mg per kg of ketamine into the abdominal cavity. We drew a 2 7 cm skin flap of a random shape, which had its basis in the caudal part, in the centre of the back, and then elevated the flap including the skin, subcutaneous tissue and panniculus carnosus from the fascial layer, and put the flap back in its original position and sutured it. Thereafter, the control group was injected with 10 ml of physiological saline hypodermically to the gluteal region once a day for 14 days, and the experimental groups were administered, respectively, 200 mg, 500 mg and 1000 mg of ascorbic acid to the gluteal region through hypodermic injection once a day for 14 days. The flap survival rate was measured using the papertemplate technique e which copies the necrotic area of the flap using a transparent section paper on days 3, 7 and 14 after the surgery e and calculated using the following formula:

Free Flap Coverage of Extensive Soft Tissue Defect in Cutaneous Aspergillosis: A Case Report

Isolated fungal soft-tissue infections are uncommon, but may cause severe morbidity or mortality. Aspergillosis infection is rare, but the frequency in increasing over the last two decades. Here, we present a patient with cutaneous aspergillosis of his right elbow with unusual clinical and radiological features suggestive of a malignant disease, which remained undiagnosed for an extended period of time. The patient presented with necrotic, black-colored skin ulcerations. We completely removed the skin ulcer with the surrounding erythematous skin lesion, and then we reconstructed the area with thoracodorsal perforator free flap. The biopsy specimen contained septate hyphae with dichotomous branching, which is morphologically consistent with a finding of Aspergillus. After surgery, we initiated antifungal medication therapy with amphotericin B and itraconazole. At the time of follow-up, the elbow with the reconstructed flap had fully healed, and no recurrent disease was found.

Hemifacial Transplantation Model in Rats

Background To refine facial transplantation techniques and achieve sound results, it is essential to develop a suitable animal model. Rat is a small animal and has many advantages over other animals that have been used as transplantation models. The purpose of this study was to describe a rat hemifacial transplantation model and to verify its convenience and reproducibility. Methods Animals used in this study were Lewis rats (recipients) and Lewis-Brown Norway rats (donors). Nine transplantations were performed, requiring 18 animals. The hemifacial flap that included the ipsilateral ear was harvested based on the unilateral common carotid artery and external jugular vein and was transferred as a single unit. Cyclosporine A therapy was initiated 24 hours after transplantation and lasted for 2 weeks. Signs of rejection responses were evaluated daily. Results The mean transplantation time was 1 hour 20 minutes. The anatomy of common carotid artery and external jugular vein was consistent, and the vessel size was appropriate for anastomosis. Six of nine allografts remained good viable without vascular problems at the conclusion of study (postoperative 2 weeks). Conclusion The rat hemifacial transplantation model is suitable as a standard transplantation training model.