When a free flap is judged unsalvageable, surgeons should determine subsequent treatments, considering the success rate as one of the most important factors. The authors believe that simple reconstruction using a common free flap is the first choice in most cases. When regional or general conditions do not permit further free flap transfer or when defects are comparatively small, reconstruction with a pedicled flap or direct closure of the defect may be considered.
In living-donor liver transplantation (LDLT), reconstruction of the hepatic artery is challenging because the recipient artery is located deep in the abdominal cavity and the operating field is limited. Also, the hepatic artery of the graft is short and the recipient artery is occasionally damaged. To overcome these difficulties, we developed a double-needle microsuture technique for artery reconstruction. A total of 161 adult patients received 163 LDLTs using this new technique. The first suture was placed at the most difficult point in the artery to be visualized through the microscope. Each stitch was placed from the inner side of the arterial wall to the outer side. The posterior stitch was tied pulling toward the back. The subsequent sutures were advanced anteriorly on either side adjacent to the previous suture. Hepatic artery thrombosis occurred in 4 patients (2.5%), only 2 (1.2%) of which were associated with arterial reconstruction. Intimal dissection developed in the recipient artery in 2 patients (1.2%). Three (50%) of these 6 complications occurred more than 10 days after LDLT. In conclusion, this suturing technique allows for safe intimal adaptation even when the arterial tunica intima is separated from the tunica media, because all stitches are carried from inside of the vessel to the outside, contributing to more satisfactory results.
Tissue devitalization by irradiation was dose-dependent, although fractionated protocols helped to reduce it. Adipose-derived stem cells and other fat-derived products harboring adipose-derived stem cells successfully revitalized irradiated tissues and accelerated wound healing.
Background:
Fat grafting frequently requires multiple treatments and thus repeated liposuction to achieve treatment goals. The purpose of this study was to evaluate whether cryopreservation of adipose tissue may facilitate future fat grafting.
Methods:
Lipoaspirates were harvested from six women and preserved using two cryopreservation methods: (1) simple cooling to −80°C (cryo-1); or (2) programmed cooling to −196°C (cryo-2). Fresh fat, cryo-1 fat, and cryo-2 fat were analyzed both in vitro and in vivo.
Results:
Immunohistochemistry of both types of cryopreserved adipose tissue revealed that most adipocytes were necrotic. The cell number and viability of stromal vascular fraction cells were significantly decreased in cryo-1 fat (1.7 × 105 cells, 42.6 percent viable) and cryo-2 fat (2.0 × 105 cells, 55.4 percent viable), compared with fresh fat (3.9 × 105 cells, 90.6 percent viable). Although adipose-derived stem cells were cultured successfully from all fats, functional adipose-derived stem cells from cryopreserved fats were much fewer, with comparable multilineage differentiating capacity. In vivo studies using human fat grafted into immunocompromised mice revealed that, 3 months after transplantation, all of the cryopreserved fats maintained their volume to some extent; however, the cryopreserved fats were mostly filled with dead tissue and produced significantly lower engraftment scores than fresh fat.
Conclusions:
Most adipocytes were killed in the process of cryopreservation and thawing. Adipose-derived stem cells were isolated from cryopreserved fat, but the number of functional adipose-derived stem cells was very limited in both cryopreservation methods. After grafting, cryopreserved fat was retained as dead and fibrous tissue, suggesting a risk of clinical complications such as oil cysts.
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