The influence of systemic growth hormone administration on the healing time of skin graft donor sites in a pig model

A more rapid healing of skin graft donor sites has often been observed during ultimoratio therapies with growth hormone in adults who have suffered extremely severe burns. The purpose of this animal experimental study was to examine the influence of systemic growth hormone administration on the healing time of skin graft donor sites under standardized conditions in pigs. The animals were 14 (7 experimental and 7 control) male, sexually mature, German domestic pigs, in which 30 skin graft donor sites 8 cm x 4 cm and 0.6 mm deep were created. Fifteen each of the skin graft donor sites were bandaged with the same material [hydrocolloid bandage (Varihaesive E) and PVP-iodine gauze (Braunovidon Gaze)]. The test period was 15 days for each pig, whereby recombinant growth hormone (0.5 IU/kg body weight per day) was applied subcutaneously in the experimental group. The bandages were changed under brief narcosis every 2 days, during which one skin-punch biopsy was taken per skin graft donor site, and blood samples were drawn for determination of the serum IGF-1 values. Photographic documentation was also recorded. The biopsies were examined histologically (hematoxylin and eosin stain) and immunohistochemically (collagen IV and VII, and laminin), whereby histologically the start of keratinization was assessed as a healing criterion. The serum IGF-1 values in the growth hormone group were statistically significantly higher than in the control group. Immunohistochemically, a complete basal membrane was observed in both the experimental and the control group after the 7th or 8th day. A clearly elevated serum IGF-1 level correlated in the growth hormone group with the skin graft donor sites healing. It could thus be demonstrated both clinically and histologically that systemic application of growth hormone results in a statistically significantly more rapid healing of the skin graft donor sites by 2 days earlier than in the control group.     

The effect of epinephrine in local anesthesia on the survival of full- and split-thickness skin grafts: an experimental study

The effect of local anesthesia containing epinephrine on the survival of split- and full-thickness skin grafts remains unclear. In this blinded study, Xylocaine with or without epinephrine was injected subdermally prior to harvesting of split-thickness and full-thickness skin grafts on the dorsum of rabbits. After procurement, the grafts were placed back into their original donor sites. Statistical analysis of graft survival 7 days postoperatively revealed a significant decrease in survival for the full-thickness skin grafts treated with Xylocaine with epinephrine as compared with similar grafts without epinephrine (p less than 0.0005). No significant difference was noted for split-thickness skin-graft survival in grafts treated with Xylocaine with and without epinephrine (p greater than 0.1).     

Study of effects of porcine skin and bovine dermis on the healing of split-skin graft donor sites in humans.

A study was undertaken of the effects of heterografts (lyophilized porcine skin or bovine dermis) on the healing of split-skin graft donor sites. When compared with a petrolatum gauze dressing, no advantages were found. Some disadvantages developed, however, which led us to discontinue their use.     

Amniotic membrane transplantation in the treatment of persistent epithelial defect on the corneal graft

It has been shown that amniotic membrane transplantation (AMT) improves healing of the epithelium defects as it serves as a basement membrane for endothelial cells growth, prevents inflammatory cell infiltration and reduces apoptosis in keratocytes. Having in mind the healing properties of AM we investigated the efficacy of AMT in persistent epithelial defect (PED) on the corneal graft. 80 corneal grafts were prospectively followed up for presence of PED 10 months after surgery. PED was detected in 12 cases (15%) having surgery for: rejected graft (n = 4), keratoconus (n = 3), keratoconus following PK on a second eye (n = 3), corneal perforation (n = 1) and Stevens-Johnson keratopathy (n = 1). Epithelial defect (ED) developed 14 +/- 7 days after surgery in 10 cases and 1.5 month in other two. All patients were primarily conservatively treated with subconjuctival steroids and artificial tears for 10 days and systemic steroid therapy if needed after, until the period of 2 weeks. 4 patients were healed. Since ED was unresponsive to all previous treatments for more than 2 weeks, one layer of AM was placed on the corneal lesion in 5 patients, and in 3 cases of deep PED several layers of AM were placed. Healing of the defect was obtained in 7/8 (87.5%) eyes. In 1 patient second AM transplantation was necessary. Mean epithelization time was 2 weeks (range 1-3 weeks) in monolayer and 3 weeks (range 2-4 weeks) for multilayer cases. 5 out of 8 patients retained the same best corrected visual acuity (BCVA) while 3/8 patients improved their vision more than 2 lines. Preoperative corneal thickness of 255 +/- 40 mm increased to 455 +/- 90 mm. AM transplantation facilitates healing of corneal epithelium. PED on the corneal graft unresponsive to conventional treatment can be effectively cured when covered with one or more amniotic membrane layers.     

The metabolism of skin grafts stored with excess carbon dioxide.

In Japan, the long-term storage of cereals and foods in the presence of excess carbon dioxide is already a practical reality. The present study was conducted to assess the metabolic changes in skin grafts during storage in the presence and absence of excess carbon dioxide, with the aim of seeking a simple and effective method to prolong skin-graft viability during storage. In experiment 1, 120 male Wistar rats weighing 250 to 300 gm were used. A split-thickness skin graft 450 microns in thickness was harvested from the back of each rat with a dermatome and was divided into two pieces for separate storage. One piece was stored in normal air at 4 degrees C (control grafts), and the other was stored in a gas mixture composed of 20% O2, 20% CO2, and 60% N2 at 4 degrees C (CO2 grafts). Metabolic changes in the skin grafts during storage were investigated by ATP and glucose assays. In experiment 2, 60 male Wistar rats were used. Collection and storage of the split-thickness skin grafts were performed as in experiment 1. In both groups, skin grafts were stored for 1, 2, or 3 weeks, and the oxygen consumption rate of each graft was determined. Experiment 3 used 80 male Wistar rats and the same procedure as in experiment 1; split-thickness skin grafts were harvested, divided into two pieces, and stored for 1, 2, or 3 weeks. In both groups, the stored skin grafts were regrafted onto the backs of the same donor rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

MASSIVE AND RECURRENT HERNIAS—Use of Dermal Grafts in Carrying Out Repair

Graft of dermis is clinically and experimentally superior to graft of whole skin for use as reinforcement at the site of repair of hernia, for gross cysts do not form and it fuses better with the surrounding tissues than does whole skin. Placing either dermis or skin under tension helps prevent cyst formation and aids fusion with surrounding tissues. Dermal grafts are less liable to infection than are whole skin grafts, either at the time of operation or later.A split-split flap dermatome technique is presented as a preferred technique for obtaining a dermal graft from the thigh in cases of ventral hernia in which the abdominal skin is stretched, attenuated and inelastic because of the massive size of the hernia. This technique was used in 27 cases of massive hernia. There was infection in one case of the 27 and subsequent healing was satisfactory. One patient died of spontaneous rupture of an intracranial carotid aneurysm. Hernia did not recur in any patient.A split-split free graft dermatome technique is presented for use in cases in which an elliptical segment of normal skin can be removed adjacent to an inguinal or thoracic incision for repair of a hernia or other use. This technique was used in seven cases of inguinal hernia and in one of diaphragmatic hernia with satisfactory results.     

Improved healing of microvascular PTFE prostheses by induction of a clot layer: an experimental study in rats

This study was undertaken to test the hypothesis that the induction of a clot layer on the graft surface of microvascular polytetrafluoroethylene (PTFE) prostheses might improve their healing. PTFE microvascular prostheses (n = 18), mechanically roughened PTFE microvascular prostheses (n = 18), and Chitosan-impregnated PTFE microvascular prostheses (n = 18) (all prostheses: length 1 cm, inside diameter 1.5 mm, fibril length 30 microns) were implanted into the abdominal aortas of rats and were evaluated at 3 days (n = 3), 10 days (n = 3), 3 weeks (n = 6), and 6 weeks (n = 6) with regard to the presence or absence of a clot layer and with regard to the amount of graft healing. All untreated PTFE prostheses were never found to be covered with a clot layer, only scarcely with some platelets, and showed poor neoendothelial healing; even at 6 weeks after implantation, there was only endothelial cell coverage near the anastomotic sides (coverage = 19 +/- 4 percent). The endothelial cells were present directly on the graft surface. In contrast, both the roughened and the Chitosan-impregnated PTFE prostheses were completely covered with a thin clot layer upon implantation and demonstrated significantly better neoendothelial healing (endothelial cell coverage at 6 weeks = 76 +/- 22 percent and 75 +/- 18 percent, respectively; p less than 0.001); moreover, in these prostheses, the endothelial cells were present on a matrix of smooth-muscle cells, which covered the graft surface completely. These results confirm our hypothesis that the induction of a clot layer on the graft surface of microvascular PTFE prostheses improves their healing.(ABSTRACT TRUNCATED AT 250 WORDS)     

游离植皮联合负压封闭引流治疗骨科创面的临床研究

目的：观察游离植皮联合负压封闭引流（vacuumsealingdrainage,后文简称VSD）对骨科创面的疗效,并与植皮后传统加压包扎相比较,为临床实践提供更好的治疗方法。方法：对广州中医药大学第一附属医院创伤骨科2008年3月至2010年2月收治的65例感染创面病例采取手术清创后予VSD引流,合理应用抗生素,创面感染得到控制后,创面干净,肉芽生成良好,外露的肌腱、骨膜表面有新鲜的肉芽组织覆盖,达到植皮的要求后,随机分成两组,其中30例（实验组）采用游离植皮联合VSD法闭合创面,35例（对照组）采用游离植皮加压包扎植皮区,对两组术后的平均换药次数、创面平均愈合时间、植皮成活率情况、平均住院时间（植皮后）、平均抗生素应用次数（植皮后）进行统计学分析,采用t检验和卡方检验,对此两种方法进行评价。结果：植皮联合VSD组与植皮加压包扎组,在平均换药次数、创面平均愈合时间、植皮成活率、平均住院时间（植皮后）、平均抗生素应用次数（植皮后）的对比,有显著性差异（P〈0.05）。结论：创面达到游离植皮条件后,游离植皮联合VSD负压引流可以促使皮片黏附,保持创面洁净,避免皮下渗液积聚,有利于皮片的存活,与植皮加压包扎组相比,减少了平均换药次数,缩短创面平均愈合时间及平均住院时间（植皮后）,减少抗生素平均应用次数,提高了植皮成活率,说明游离植皮联合VSD组优于游离植皮加压包扎组,游离植皮联合VSD法治疗骨科创面有显著疗效。该手术方法操作简单,术后护理方便,是一种较理想的植皮后的固定方法,有利于创面的愈合,值得临床推广应用。     

The effect of low-energy laser on skin-flap survival in the rat and porcine animal models.

Low-energy lasers are currently being used in the therapy of rheumatoid arthritis, chronic pain, muscle strain, and the promotion of wound healing in human and veterinary medicine. This study examined the effects of low-energy laser on skin-flap survival in a controlled interspecies study using the rat and porcine models. Twenty dorsal skin flaps based caudally were performed in 20 rats (10 laser-treated and 10 control flaps). The wounds were closed, and the flaps were sutured over the skin. Forty dorsal pig skin flaps based medially were raised in five pigs. The flaps were treated once per day for 10 days: 4 days preoperatively, the day of surgery, and 5 days postoperatively (30 s/cm3 per day). The average surviving rat flap surface area for the laser-treated flaps was 653 +/- 112 mm (mean +/- SD) and 580 +/- 60 mm in the control flaps, which was not significant (p greater than 0.05). In the porcine model, the average surviving area for the 20 laser-treated flaps was 949 +/- 174 mm, and the control average (n = 20) was 969 +/- 147 mm, also not significant. No beneficial effect was seen with low-energy laser preoperative and postoperative treatment of skin flaps in the rat and porcine models.     

超短波促进烧伤肉芽创面植皮片愈合的临床观察

目的:观察超短波对烧伤肉芽创面受皮区皮片成活的影响。方法:32例自身对照邮票皮移植及40例整张刃厚皮移植术后根据是否给予超短波治疗分别分为两组,治疗组术后接受无热量超短波治疗,对照组术后未接受超短波治疗,观察创面完全愈合时间和愈合创面水泡出现情况进行疗效判定。结果:根据两组患者创面愈合时间进行比较,治疗组明显低于对照组(P<0.01);而在创面水泡出现程度比较中,实验组水泡发生率和严重程度均明显低于对照组(P<0.05)。结论:超短波治疗能明显促进烧伤肉芽创面植皮片的成活,加速烧伤创面的愈合。     

In search of improved fat transfer viability: a quantitative analysis of the role of centrifugation and harvest site

Fat grafting is an unpredictable procedure that continues to challenge the field of plastic surgery due to irregular resorption. Applications for this procedure are broad in both reconstructive and cosmetic plastic surgery. Fat grafts are carefully obtained and manipulated to obtain better graft takes and results, yet there is no universal agreement on what constitutes an ideal methodology. The present study examines adipocyte viability from four commonly used donor sites in five subjects. No statistical differences in adipocyte viability were demonstrated among abdominal fat, thigh fat, flank fat, or knee fat donor sites that were immediately removed and untreated (p < 0.225). In addition, no differences were observed in representative tissue samples that were removed and centrifuged (thigh, p = 0.508; knee, p = 0.302; flank, p = 0.088; abdomen, p = 0.533). On the basis of these quantitative data, neither harvest location nor centrifugation demonstrated any advantage in terms of lipocyte viability. Fat tissue transfers from these common sites may be considered equal, and centrifugation does not appear to enhance immediate fat tissue viability before implantation.     

An alternative method to minimize pain in the split-thickness skin graft donor site

In the art of plastic surgery, the reconstruction of tissue defects to obtain cosmetic and functional recovery is the major concern. Skin grafting is the most frequently used procedure for reconstructing defects of various size and anatomical localizations. On the other hand, donor-site problems associated with this invaluable procedure are inevitable. Various methods are used in the postoperative management of the partial-thickness donor site created during the harvest of a split-thickness skin graft. Each technique has the potential for complications of fluid loss, excessive pain, prolonged period of healing and immobilization, hypertrophic scarring, and undesirable pigmentation. Donor-site pain is probably the most disturbing complication in the early postoperative period. The aim of this article is to point out the significance of donor-site pain, which has not been emphasized thoroughly in the literature, and to introduce flap skin as a potential graft donor site for patients in whom reduction of donor-site morbidity is of primary concern. The principal goal of the technique described in this article is to eliminate donor-site pain by harvesting the graft from the flap that is insensate after the elevation. In 15 patients, the overlying skin of the flap that had been used for reconstructive purposes was used as the donor site (group I). In the remaining 23 patients, the posterolateral thigh was used as the donor site (group II). Donor-site discomfort was recorded during the first 8 days postoperatively using a visual analogue scale. To analyze the data, we used the Friedman test, Dunn's multiple comparison test, and Mann-Whitney U test. It was observed that the visual analogue scale of both of the groups showed a significant decrease within days (group I, p < 0.0001; group II, p < 0.0001). The mean pain scores were significantly lower in group I than in group II (p < 0.0001). When donor-site pain is of primary concern, this procedure provides uneventful and comfortable healing while avoiding postoperative pain in the donor site. For that reason, this technique might be used in appropriate cases to minimize donor-site pain.     

Effect of isolation of periosteum and dura on the healing of rabbit calvarial inlay bone grafts

Little is understood about the role of the recipient site in the revascularization and incorporation of autogenous inlay bone grafts in the craniofacial skeleton. Clinical experience demonstrates that secondary complex cranial vault reconstruction performed with scarred avascular dura or poor soft-tissue coverage may undergo significant resorption, thus compromising the aesthetic outcome. This study was designed to determine the effect of isolating autogenous orthotopic inlay calvarial bone grafts from the surrounding dura and/or periosteum on graft revascularization, healing, and volume maintenance in the adult rabbit. Adult rabbits were randomized into four groups (n = 10 per group); in each rabbit, the authors created a circular, 15-mm in diameter, full-thickness cranial defect followed by reconstruction with an autogenous calvarial bone graft, which was replaced orthotopically and held with microplate fixation. Silicone sheeting (0.5 mm thickness) was used to isolate the dura (group II), the periosteum (group II), or both dura and periosteum (group IV) from the graft interface. No silicone was placed in group I. Animals were killed 10 weeks postoperatively, and calvaria were harvested to assess graft surface area, morphology, quantitative histology, fluorochrome staining, and revascularization. Grafts isolated from both the dura and periosteum exhibited significant decreases in total bone (cortical and trabecular) surface area, blood vessel count, and interface healing compared with nonisolated control grafts. Isolation of either the dura or periosteum significantly (p < 0.05) decreased blood vessel count but had no significant effect on interface healing. Isolation of the dura alone was associated with a significant (p < 0.05) decrease in graft cross-sectional surface area and dural cortical thickness compared with nonisolated control grafts, but this effect was not observed when the periosteum alone was isolated. Quantitative histology performed 10 weeks after surgery indicated that graft isolation was associated with increased marrow fibrosis and necrosis compared with nonisolated controls; it also demonstrated evidence of increased activity in bone remodeling (osteoblast and osteocyte count, new trabecular bone, and surface resorption). Triple fluorochrome staining suggested increased bone turnover in the nonisolated grafts compared with isolated grafts at 1 and 5 weeks postoperatively. This study demonstrates that isolating a rabbit calvarial inlay autogenous bone graft from the dura and/or periosteum results in significantly (p < 0.05) decreased revascularization, interface healing, and cross-sectional areas of amount of mature bone compared with nonisolated control grafts 10 weeks after surgery. At this time point, histologic examination demonstrates a paradoxical increase in bone remodeling in isolated bone grafts compared with controls. It is possible that the inhibition of revascularization results in a delayed onset of the remodeling phase of graft incorporation. However, in the model studied, it is not known whether the quantitative histologic and morphometric parameters measured in these isolated grafts exhibit a "catch-up" phenomenon at time points beyond 10 weeks after surgery. The results of this study emphasize the importance of a healthy recipient site in the healing and incorporation of calvarial bone grafts but stress the need for further investigation at later time points.     

Systemic rather than local heme oxygenase-1 overexpression improves cardiac allograft outcomes in a new transgenic mouse

Heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme catabolism, exhibits potent antioxidant and anti-inflammatory properties. We developed HO-1 transgenic (Tg) mice using a rat HO-1 genomic transgene under the control of the endogenous promoter. Transgene expression was demonstrated by RT-PCR in all studied tissues, and a modest HO-1 overexpression was documented by Western, ELISA, and enzyme activity assays. To assess the effect of local vs systemic HO-1 in the acute rejection response, we used Tg mice as organ donors or recipients of MHC-incompatible heart grafts. In the local HO-1 overexpression model, Tg allografts survived 10.5 +/- 0.7 days (n = 10), compared with 6.5 +/- 0.4 days (n = 6) for wild-type donor controls (p = 0.0001). In the systemic HO-1 overexpression model, Tg recipients maintained allografts for 26.8 +/- 3.4 days (n = 10), compared with 6.3 +/- 0.1 days (n = 12) in wild-type controls (p = 0.00009). Inhibition of HO activity by treatment with tin protoporphyrin blunted survival advantage in Tg mice and resulted in acute graft rejection (n = 3). Increased carboxyhemoglobin levels were consistently noted in Tg mice. Comparisons of grafts at day 4 indicated that HO-1 overexpression was inversely associated with vasculitis/inflammatory cell infiltrate in both models. Hearts transplanted into Tg recipients showed decreased CD4(+) lymphocyte infiltration and diminished immune activation, as judged by CD25 expression. Thus, although local and systemic HO-1 overexpression improved allograft outcomes, systemic HO-1 led to a more robust protection and resulted in a significant blunting of host immune activation. This Tg mouse provides a valuable tool to study mechanisms by which HO-1 exerts beneficial effects in organ transplantation.     

The use of allogeneic cultivated keratinocytes for the early coverage of deep dermal burns – indications, results and problems

Since 1995, keratinocytes are grown into cultures and used as allografts for the coverage of deep dermal defects in our burn unit. Donor skin samples are mostly acquired from other burn patients. In addition, special methods of skin preservation allow us the use of skin, which has been taken in redundancy for split thickness skin grafting from nonburned patients.Thirty five patients with deep partial thickness burns in the face were treated since 1996 according to the following concept: Dermabrasion or tangential excision was performed before the 5(th) day following trauma. If viable dermis was present, the wounds were covered with sheets of allogeneic cultivated keratinocytes. In cases of deeper defects, autologous skin grafts were applied. In 23 cases, epithelialisation was achieved within 10 days, in 8 patients, a prolonged duration until complete healing was observed. In 5 faces, coverage of residual defects with skin grafts was necessary. The mentioned problems of wound healing occurred from infection, incomplete excision of burn eschar and a depth of the wound which was retrospectively seen too deep for the treatment with keratinocytes. At follow up, patients were examined clinically and functionally with Frey's faciometer(R), which is an instrument for quantification of mimic movements. In cases of uncomplicated healing, a nearly complete restitution was found.Other indications include deep dermal burns in children and the coverage of early excised wounds in adults, with a reasonable amount of viable dermis remaining, both resulting in a significant reduction of donor-site morbidity. In severely burned adults with limited donor sites, it offers the possibility of immediate definite coverage of large areas.     

Validation of a model for the study of multiple wounds in the diabetic mouse (db/db)

The genetically diabetic db/db mouse exhibits symptoms that resemble human type 2 diabetes mellitus, demonstrates delayed wound healing, and has been used extensively as a model to study the role of therapeutic topical reagents in wound healing. The purpose of the authors' study was to validate an excisional wound model using a 6-mm biopsy punch to create four full-thickness dorsal wounds on a single db/db mouse. Factors considered in developing the db/db wound model include reproducibility of size and shape of wounds, the effect of semiocclusive dressings, comparison with littermate controls (db/-), clinical versus histologic evidence of wound closure, and cross-contamination of wounds with topically applied reagents. The size of wounds was larger, with less variation in the db/db mice (31.11 +/- 3.76 mm2) versus db/- mice (23.64 +/- 4.78 mm2). Wounds on db/db mice that were covered with a semiocclusive dressing healed significantly more slowly (mean, 27.75 days) than wounds not covered with the dressing (mean, 13 days; p < 0.001), suggesting the dressings may splint the wounds open. As expected, wounds healed more slowly on db/db mice than db/- mice (covered wounds, 27.75 days versus 11.86 days, p < 0.001; wounds not covered, 13 days versus 11.75 days, p = 0.39). Covered wounds, thought to be closed by clinical examination, were confirmed closed by histology only 62 percent of the time in the db/db and 100 percent of the time in the db/- mice. Topical application of blue histologic dye or soluble biotinylated laminin 5 to one of the four wounds did not spread locally and contaminate adjacent wounds. Multiple, uniform, 6-mm wounds in db/db mice heal in a relatively short time, decrease the number of animals needed for each study, and allow each animal to serve as its own control. The db/db diabetic mouse appears to be an excellent model of delayed wound healing, particularly for studying factors related to epithelial migration.     

Comparison of organ cultured precut corneas versus surgeon-cut corneas for Descemet’s stripping automated endothelial keratoplasty

To compare precut and surgeon-cut organ cultured donor corneas for DSAEK. A total of 119 consecutive eyes treated with DSAEK were retrospectically identified. 65 grafts were cut by the surgeon (Moria, ALTK System) prior to DSAEK and 54 grafts were precut by laboratory technicians from the Danish Eye Bank (Horizon single-use system). 1 year after surgery, tomographic images were obtained with the Pentacam HR. Endothelial cell density (ECD) and best-corrected visual acuity (BCVA) was determined. Graft thickness and graft asymmetry was evaluated in the centre and 1 mm from the edge of the graft in 6 semi-meridians. 1 year after surgery, the ECD loss was similar in the two groups, averaging 25.9 ± 14 % in surgeon-cut, and 22.9 ± 17 % in precut group (p = 0.33). Mean central graft thickness was 172 ± 6 μm in surgeon-cut grafts and 182 ± 6 μm in precut grafts (p = 0.30). BCVA was similar in surgeon-cut and precut corneas; being 0.25 ± 0.02 logMAR and 0.24 ± 0.02 logMAR, respectively (p = 0.59). The graft asymmetry index was 1.48 ± 0.02 for surgeon-cut and 1.44 ± 0.02 for precut grafts. There were no significant differences in complications rate in both groups. No correlations between BCVA and central graft thickness or graft asymmetry index in both groups were observed. Organ cultured precut donor corneas are comparable with surgeon-cut grafts with respect to ECD, graft thickness and asymmetry, and postoperative complication rate.     

Cyclosporine and experimental skin allografts: long-term survival in rats treated with low maintenance doses

Although cyclosporine (CsA) is a powerful immunosuppressive agent in organ transplantation, its efficacy in skin transplantation has not been examined completely. We have tested it as primary immunosuppression in a rat skin allograft model. Histoincompatible Brown-Norway skin grafts are rejected in untreated Lewis hosts within 9 +/- 1 days but survive for 22 +/- 3, 34 +/- 2, or 41 +/- 8 days after 7, 14, or 21 days of CsA treatment (15 mg/kg per day subcutaneously), respectively (p less than 0.001). Animals treated daily for 4 weeks died from drug toxicity; however, an initial 2-week course followed by a low maintenance dose (15 mg/kg every fourth day) produced indefinite (greater than 150 days) graft acceptance without side effects. The long-surviving grafts were supple, grew long hair, and showed normal histology. When the drug was stopped at any time during this maintenance period, early signs of rejection (hair loss, epidermal breakdown, and localized ulceration) occurred, which could be reversed completely by a short CsA "pulse" (15 mg/kg per day for 7 days). These experimental data support the potential application of CsA immunosuppression in human skin allotransplantation.     

The use of skin grafts in postburn contracture release: a 10-year review

Postburn scarring and contracture affecting function remain the most frustrating late complications of burn injury. Various techniques are used to release contractures; the choice depends on their location and/or the availability of unaffected skin adjacent to the contracture or elsewhere. A retrospective review was carried out of the case notes of patients who had skin grafting for the release of postburn contracture at the Burns Unit, City Hospital, Nottingham between May of 1984 and August of 1994 to evaluate the experience over this period. Information was obtained about the burn injury, contracture site, interval between burn and release of contracture, indication, age at first release, intervals between releases, operative details (donor and graft sites), complications and nonoperative treatment, and follow-up to the end of the study period. A total of 129 patients underwent skin grafting for release of contractures as opposed to any other method of correction. Full-thickness skin grafts were used in 81 patients (63 percent) and split-thickness skin grafts in 26 (20 percent). Twenty-two patients (17 percent) had both types used on different occasions. Flame burns (41 percent) were the most common causes, followed by scalds (38 percent). Two hundred thirty-nine sites of contracture were released, with the axilla (59) and the hand/wrist (59) being the most common sites involved, followed by the head/neck region (42). It was found that for the same site, release with split-thickness skin grafts was associated with more rereleases of the contracture than with full-thickness skin grafts. Also, the interval between the initial release and first rerelease was shorter than with full-thickness skin grafts (p < 0.048). It was also noted that children required more procedures during growth spurts, reflecting the differential effect of the growth of normal skin and contracture tissue. Patients reported more satisfaction with texture and color match with the full-thickness skin grafts. There was comparable donor-site and graft morbidity with both graft types. The use of skin grafts is simple, reliable, and safe. Whenever possible, the authors recommend the use of full-thickness skin grafts in preference to split-thickness skin grafts in postburn contracture release.     

Osteochondral graft fixation using a bioresorbable bone cement

Multiple osteochondral grafts can be used to resurface large joint defects in both humans and horses. In humans, immediate postoperative weight bearing can be prevented, however in the equine, it is unavoidable. Early weight bearing can create detrimental graft micromotion. The aim of this study was to investigate the role of a bioresorbable cement in improving the initial stability of multiple osteochondral graft repairs of large subchondral cystic lesions in the horse. Configurations employed for filling a 20mm diameter cylindrical defect included: (A) twelve 4.5mm diameter grafts with cement, (B) five 6.5mm diameter grafts with cement, (C) four each of 4.5mm and 6.5mm grafts with cement and (D) cement only. Intact bone slices (E) were also tested. Push-out tests were used to quantify construct to host sidewall interface fixation. Configuration (A) proved clinically impractical (n=3). Configurations (B) (n=6), and (C) (n=4) had statistically similar interface stiffnesses and failure stresses (43+/-8 and 30+/-12 MPa and 0.96+/-0.1 and 1.2+/-0.3 Mpa, respectively) suggesting that they are equally susceptible to interface movement in the immediate postoperative period. By way of comparison, defects filled only with cement had an average stiffness of 53+/-7MPa and failure stress of 1.8+/-0.3 MPa (n=6) while the intact femoral condyle demonstrated a stiffness of 108+/-7 MPa and failure stress of 18+/-0.4 MPa (n=6). Cement augmentation improved immediate postoperative stability of multiple osteochondral graft constructs over uncemented constructs, although in all cases the observed moduli of elasticity and yield stress values were lower than those observed for cement only and intact bone test specimens. (all numbers are mean+/-SEM).