Treatment of necrotising fasciitis using glycerol-preserved skin allografts for temporary wound coverage.

Allografts of human skin have been used for both temporary and permanent wound coverage. They are useful as temporary bridges for the critically ill patient who is not allowed to receive definite wound coverage, or for wound bed preparation before permanent grafting. Glycerol-preserved skin allografts have several benefits including good adherence to the wound bed, water vapour transport, antimicrobial characteristics, low toxicity and antigenicity, ease of application and removal, a long shelf-life, and minimal storage requirements. We achieved lower limb salvage using a glycerol-preserved skin allograft for temporary wound coverage in the treatment of necrotising fasciitis.

Versatility of right gastroepiploic and gastroduodenal arteries for arterial reconstruction in adult living donor liver transplantation.

BACKGROUND: In cases where there is severe intimal dissection in the recipient hepatic artery (HA), or if the HA has been used already and additional operations are needed due to graft rejection or arterial occlusion, an alternative is necessary. In the present study, we have reported the feasibility of using the right gastroepiploic artery (RGEA) and gastroduodenal artery (GDA) in various situations where the HA is not a feasible option. METHODS: Among 463 patients who underwent primary adult-to-adult living donor liver transplantation from January 2002 to July 2010, eight subjects required alternative vessels. Four recipients displayed severe intimal injury associated with previous transarterial chemoembolization (TACE); two, required a salvage operation due to hepatic artery thrombosis (HAT); and two, retransplantations due to chronic rejection. The RGEA was used in five and the GDA in three patients. RESULTS: Postoperative Doppler ultrasonography and three-dimensional computed tomography showed patent arterial flow in all patients. However, HAT recurred in one patient who underwent a salvage operation with the RGEA; she died 2 months later. Two other patients died due to wound infection and respiratory failure within 3 months despite intact hepatic arterial flow. Four patients had no further complications during follow-up (mean = 33 months). CONCLUSION: Although there was a discrepancy in the diameter of the HA and the RGEA (or GDA), there was no problem with mobilization and microanastomosis. We therefore believe that these vessels can be good alternatives when the hepatic artery is unavailable.

A new venous conduit utilizing the recipient portal vein branches for segment V in adult partial liver transplantation.

Right anterior-medial lobe congestion due to temporary clamping of segment V and/or VIII is common in the operative theater during adult donor right lobe liver transplantation, the most common procedure in our institute. We have used an autogenous saphenous vein conduit to recipient portal vein tributaries in 15 cases, as a "Y-to-I venoplasty" since January 2004. The recipient portal vein is transected 5 mm proximal to its bifurcation and extended to both sides with partial hepatic dissection. The "Y-to-I venoplasty" is made by suture closure of the portal vein transversely to form a tube. The average length is 7.5 cm with a 1.3 cm width. One end of "Y-to-I venoplasty" conduit is anastomosed to the donor segment V branch on the back table. And the other end is anastomosed directly to the IVC via a new window or the middle hepatic vein stump in recipient. The phase distension of the conduit with respiration is noted in the operative field. A 6/15 (40%) patency rate, was observed by CT angiography at the second postoperative week. All-patient conduits showed good flow on serial examinations at the 60th postoperative day. This new venous graft, made of recipient portal vein is a good conduit for segment V decongestion in adult right lobe partial liver transplantation.

Platelet supernatant promotes proliferation of auricular chondrocytes and formation of chondrocyte mass.

Recently proposed procedures for in vitro generation of new cartilage may be difficult to perform in humans because so many chondrocytes are needed for tissue engineering. In this study the authors investigated new, efficient, low-cost techniques for the isolation and culture of chondrocytes from the ear cartilage of the rabbit. They performed a low-density monolayer culture with a low concentration (0.5%, 1%) of human platelet supernatant and observed cell proliferation (seeding efficiency, deoxyribonucleic acid synthesis), matrix synthesis (glycosaminoglycan synthesis), and the expression of type I and type II collagen (reverse transcriptase polymerase chain reaction). Seeding efficiency was increased in 1% of platelet supernatant-treated cultures by two to three times compared with untreated controls. One percent platelet supernatant had increased the incorporation of [3H]-thymidine by 1.9 to 2.5 times at 72 hours compared with controls. Glycosaminoglycan synthesis was increased in platelet supernatant-treated chondrocytes at 96 hours compared with controls. Chondrocytes treated with 1% platelet supernatant showed a decreased expression of the type II collagen gene. Supplementation with a high concentration (10%) of the platelet supernatant provided the conditions for in vitro chondrocyte mass formation. These results indicate that proliferation and matrix synthesis of auricular chondrocytes is stimulated by a low concentration of platelet supernatant. On the other hand, chondrocytes were immobilized by a high concentration of platelet supernatant. Platelet supernatant may be useful as an inexpensive autologous source of multiple growth factors to enhance chondrocyte proliferation, and also may play the role of scaffold for chondrocytes. Additional investigation is underway to generate culture conditions that promote the differentiation as well as the proliferation of chondrocytes.

Replantation of fingertip amputation by using the pocket principle in adults.

There are several treatment modalities for zone 1 or zone 2 fingertip amputations that cannot be replanted by using microsurgical techniques, such as delayed secondary healing, stump revision, skin graft, local flaps, distant flaps, and composite graft. Among these, composite graft of the amputated digit tip is the only possible means of achieving a full-length digit with a normal nail complex. The pocket principle can provide an extra blood supply for survival of the composite graft of the amputated finger by enlarging the area of vascular contact. The surgery was performed in two stages. The amputated digit was debrided, deepithelialized, and reattached to the proximal stump. The reattached finger was inserted into the abdominal pocket. About 3 weeks later, the finger was removed from the pocket and covered with a skin graft. We have consecutively replanted 29 fingers in 25 adult patients with fingertip amputations by using the pocket principle. All were complete amputations with crushing or avulsion injuries. Average age was 33.64 years, and men were predominant. The right hand, the dominant one, was more frequently injured, with the middle finger being the most commonly injured. Of the 29 fingers, 16 (55.2 percent) survived completely and 10 (34.5 percent) had partial necrosis less than one-quarter of the length of the amputated part. The results of the above 26 fingers were satisfactory from both functional and cosmetic aspects. Twenty of the 29 fingers, which had been followed up for more than 6 months (an average of 16 months), were included in a sensory evaluation. Fifteen of these 20 fingers (75 percent) were classified as "good" (static two-point discrimination of less than 8 mm and normal use). From the overall results and our experience, we suggest that the pocket principle is a safe and valuable method in replantation of zone 1 or zone 2 fingertip amputation, an alternative to microvascular replantation, even in adults.

Efficient in vitro model for immunotoxicologic assessment of mammary silicone implants.

In clinical and experimental studies, silicone gel has been assumed to cause immune alterations that may be related to macrophage activation of silicone implants. However, it has not been proven that the immunotoxicities are caused by the direct contact of macrophages and silicone gel because there has not been an adequate experimental model. In the present study, silicone gel was loaded directly onto Petri dishes and was distributed uniformly to the bottom by centrifugation. Peritoneal macrophages and splenic lymphocytes were cultured either on the silicone-coated plates or on the conventional, normal plates, and their functions were compared with each other. The experiments were repeated three times. The cytotoxic activities of peritoneal macrophages on cancer cells were markedly augmented by cultivation on silicone gel, and the primary T-dependent immunoglobulin M response in which macrophages participated as antigen presenting cells was also enhanced by incubation on silicone gel. However, macrophage-unrelated functions mediated by B and T lymphocytes were not affected by the silicone gel treatment. It was proven that the direct contact of macrophages with silicone gel was a primary cause of acute immune activation that was related to foreign body reaction. In addition, the present in vitro model exhibited similar silicone-induced immunotoxicities in previous animal and clinical studies.

Topical silicone gel for the prevention and treatment of hypertrophic scar.

We studied the effects of a silicone gel bandage that was worn for at least 12 hours daily on the resolution of hypertrophic burn scar. In a second cohort, the prevention of hypertrophic scar formation in fresh surgical incisions by this bandage was also evaluated. In 19 patients with hypertrophic burn scars, elasticity of the scars was quantitated serially with the use of an elastometer. An adjacent or mirror-image hypertrophic burn scar served as a control. Scar elasticity was increased after both 1 and 2 months compared with that in controls. There was corresponding improvement clinically that persisted for at least 6 months. In the other cohort, scar volume changes in 21 surgical incisions were measured before and after 1 and 2 months. Gel-treated incisions gained less volume than control incisions after both intervals. Clinical assessment corroborated this quantitative demonstration of a decrement in scar volume. We concluded that topical silicone gel is efficacious, both in the prevention and in the treatment of hypertrophic scar.

Microvascular free tissue reconstruction following Mohs' micrographic surgery for advanced head and neck skin cancer.

Seven consecutive patients from 1986 through 1989 for 8 extensive recurrent and/or irradiated skin cancers of the face and scalp are retrospectively evaluated. One patient was treated by conventional surgical margins, and the limitations of this method in sampling margins are compared to the Mohs' micrographic surgery (MMS) used for the other 6 patients. All were treated with free flaps without flap loss or major complications in spite of advanced age. The advantages of an interdisciplinary approach to achieve maximum cure rates, optimal reconstruction, and minimizing anesthesia time are discussed.

Continuous versus conventional tissue expansion: experimental verification of a new technique.

Historically, tissue expansion is a prolonged process, typically requiring at least 6 weeks to complete. Recently, interest has increased in shortening this time period. In the current study, a continuous infusion device maintaining constant expander pressure less than capillary filling pressure was used in a canine model in seven dogs to minimize the time period needed to achieve significant expansion. There were no complications, except one device malfunction, corrected by changes in design. The process was shown to be a safe and effective means of producing amounts of expansion similar to traditional methods in approximately 72 hours, with expansion of 28 percent (n = 6) for continuous tissue expansion (CTE) versus 34 percent (n = 6) for a 2-week rapid expansion protocol. This expansion was derived from either stretch of preexisting tissue (46 percent for CTE, 35 percent for 2-week expansion) or recruitment of adjacent tissue. The clinical application of continuous tissue expansion could permit the advantages of tissue expansion to be obtained in many more situations than are currently available to traditional tissue expansion techniques.

Effects of ischemia on ulcer wound healing: a new model in the rabbit ear.

To study the effects of alteration of blood flow on wound healing in rabbit ear ulcers, two models were designed that produced maximum ischemia and maximum congestion, respectively, with complete survival of the ear by selective division of one or more of three arteries or veins and circumferential incisions. After selection of the best models from six variations, tissue perfusion was measured indirectly by venous oxygen tension, dermofluorometry, pulse oximetry, and skin temperature. Wound healing was measured seven days after creating 6-mm surgical ulcers. The tissue oxygen tension calculated from the venous oxygen tension fell to 30 mm Hg through days 1, 3, and 7 in the ischemic ears, and skin temperature and blood flow measured by dermofluorometry were similarly affected. However, there was no evidence of significant change in tissue perfusion except increased skin temperature in the congested ears. None of the ischemic wounds were epithelialized completely, but half of the control and congested wounds were. The granulation tissue formation was decreased (39% of the area versus 63% of the area) and the infection rate was increased (20% versus 2%) significantly in the ischemic wounds compared with the control wounds but not in the congested wounds. The ischemic ulcer model is reproducible and quantifiable and is potentially a useful model for examining agents to improve ulcer healing where blood flow is decreased. The congestion model showed no significant changes in blood flow or wound healing.

Topical silicone gel: a new treatment for hypertrophic scars.

A prospective, controlled clinical trial was designed to assess the efficacy of a new treatment of hypertrophic scars. Silicone gel sheeting was applied to 14 hypertrophic scars in 10 adults for 8 weeks. The treated scars and untreated, mirror-image or adjacent control scars were photographed, biopsy specimens were taken, and they were measured elastometrically before and after treatment. Photography and elastometry were repeated 4 weeks after treatment was discontinued. All the scars that had been treated for at least 12 hours a day were improved clinically after 4 weeks. There was further clinical improvement during the second 4 weeks of treatment. Elastometrically, the treated scars were improved significantly at 4, 8, and 12 weeks, compared with both their own treatment value and the control scars (p less than 0.05). Control scars were unchanged elastometrically. Clinical improvement persisted for at least 4 weeks after treatment was discontinued. The silicone gel sheeting was well tolerated, except for occasional transient rashes or superficial maceration--both of which resolved promptly when treatment was withdrawn. There was no histologic evidence of inflammation or foreign body reaction suggesting that silicone had entered the treated tissues. We conclude that this simple method of treating hypertrophic scar is efficacious, even in relatively chronic cases. The mechanism of action of silicone gel, which is apparently not related to compression, remains to be determined.