Burn injuries and soft tissue traumas complicated by mucormycosis infection: a report of six cases and review of the literature.

Mucor fungus infection is a rare opportunistic infection, rapidly progressive and often fatal in immunocompromised patients, or in patients with chronic debilitating diseases. We report six cases of trauma patients with mucormycosis. Three had severe thermal burns, one of them with a medical history of diabetes mellitus. The other three patients suffered from severe soft tissue injuries caused by traffic accidents. In all cases there had been spontaneous exposure and contact of the wounds with soil. During hospitalization, fungi cultures and/or biopsies of all wounds were performed and all resulted positive. The patients were treated with Amphotericin B (AmB) and surgical debridement. Two of them died and the other four were fully healed and discharged. Mucormycosis should be considered in any case of aggressive skin tissue necrosis with a history of soiled wounds. We suggest that mucormycosis is treated by intravenous and local administration of AmB, extensive and repeated debridement and cautious coverage of the wound. The plastic surgeon must wait for negative swab cultures and biopsies before covering the defects with skin grafts or flaps. Reconstruction may be challenging, depending on the extent, depth, location and special indications of the affected site and the donor site availability.

L'infection fongique (mucor mycose) est une infection rare, opportuniste, d'aggravation rapide et d'évolution souvent fatale chez les patients immunodéprimés ou porteurs d'affections chroniques fragilisantes. Nous rapportons 6 cas de traumatismes avec mucor mycoses; 3 d'entre eux présentaient des brûlures thermiques sévères: l'un était atteint de diabète, les 3 autres patients souffraient de graves lésions des parties molles secondaires à des accidents de circulation; dans tous les cas, il s'agissait de plaies largement ouvertes et souillées; pendant l'hospitalisation les cultures ou les biopsies objectivaient la présence fongique; les patients furent traités par Amphotiricine B (AmB) et détersion chirurgicale; 2 patients moururent et les 4 autres évoluèrent vers la cicatrisation complète. La mucor mycose doit être évoquée devant tout cas de lésions cutanées profondes et nécrotiques avec notion de souillure. Nous suggérons que la mucor mycose soit traitée par administration intraveineuse et locale d'AmB avec détersion répétée, large et protection prudente de la plaie. Le chirurgien plastique doit attendre la négativité des cultures après écouvillonnage et biopsie avant de couvrir les pertes de substance par greffe ou lambeau. La reconstruction est un challenge qui dépend de l'étendue, de la profondeur, de la localisation et des particularités de la lésion ainsi que de la disponibilité de zone donneuse.

Changes in donor site selection in lower limb free flap reconstructions by integrating duplex ultrasonography in the preoperative design.

BACKGROUND: The flap selection criteria in lower extremity reconstruction are based on the wound characteristics and donor site morbidity. We hypothesized that the decision-making could be influenced by integrating Duplex Ultrasound (DU) in the preoperative design. METHODS: We retrospectively reviewed data on patients who underwent lower-extremity microvascular soft-tissue reconstruction at our institution by the same surgeon. In Group A, DU was integrated in the preoperative design of the microsurgical reconstruction, whilst in Group B the choice of free flap donor site and level of anastomosis were based on clinical criteria only. RESULTS: A total of 48 microvascular reconstructions were recorded. DU was used preoperatively in 20-patients, whilst in 28-patients flap selection was based on clinical criteria. There was a significant decrease in perforator flap (45% over 64%) and a significant increase in muscle flap preference (55% over 32%) in the DU-group. There was no significant difference (10% over 11%) in the donor site selection with considerable morbidity. There was no flap failure in the DU-group, whilst 3 flaps failed in the second-group (p< 0.05, χ(2)-test). Wound healing was significantly faster in the DU-group (21±3 days) compared to 37±3 days in the other group (p< 0.05, t-test). CONCLUSION: Preoperative ultrasound studies moved flap preference towards chimeric and muscle flaps with low morbidity to match the three-dimensional defect and to promote healing. KEYWORDS: lower limb reconstruction; free flap; donor site; duplex ultrasound.

The wash-out technique in the management of delayed presentations of extravasation injuries.

Late presentation of extravasation injuries from chemotherapeutic agents is not uncommon. Twenty-four patients with extravasation injuries presented with upper limb extravasation but without any skin necrosis between the second and the fourteenth day following injury day. We flushed out the infiltrated area with 300-500 ml of normal saline through multiple stab incisions. All 24 patients responded well to the procedure and no further complications occurred. The average time for the complete healing of the wounds was 15 days. All the patients were able to continue their chemotherapy treatment without delay. Patients were followed up for a mean period of 13 months. They all recovered with no functional deficit and only mild scarring. Early recognition and immediate treatment of extravasation injuries are of paramount importance. In cases with no evidence of skin necrosis, a delayed wash-out procedure appears to be very effective in removing the extravasated drug and minimizing further tissue damage.

Preservation of venous outflow improves transverse rectus abdominis musculocutaneous flap survival following vascular delay.

BACKGROUND: The rat abdominal island model has proved to be a reliable and reproducible model for the study of surgical delay procedures. It has been customary to simultaneously divide both the artery and the accompanying vein to obtain maximum survival of the rat TRAM flap undergoing delay procedure. This study evaluates the effect of selective arterial interruption compared to standard vascular delay on flap survival in the rat TRAM flap model. METHODS: Thirty-six Wistar rats were randomly assigned to three groups (n=12), depending on the vascular ligation selected for the initial experimental delay stage. In group A (control group) no vessels were ligated. In group B the right deep inferior epigastric vessels were preserved and the right superior and left inferior and superior deep vessels were ligated. In group C the right inferior epigastric vessels and the left inferior epigastric vein were preserved while superior epigastric vessels and the left inferior epigastric artery were ligated. For the second stage one week later, TRAM flaps were elevated based on the right deep inferior epigastric vessels, re-inset in their original position and digitally photographed. Skin island viability was determined 96 hours later using digital photography and image-analysis software SigmaScan (SPSS, Inc., Chicago, IL). RESULTS: The percentage of flap survival in control group A was 50+/-6%, in group B 60+/-4% and in group C 85+/-4%. The occlusion of the three vascular pairs in group B improved the survival percentage in comparison to the control group A, but this did not achieve statistical significance. In contrast, the percentage of flap survival in control group C was statistically significant compared to groups A and B (p<0.05, ANOVA). Zone IV exhibited no necrosis in any group C animals. CONCLUSIONS: This indicates that delay with preservation of the venous outflow of zone IV results in increased blood supply.

The beneficial effect of genetically engineered Schwann cells with enhanced motility in peripheral nerve regeneration: review.

BACKGROUND: The importance of Schwann cells in promoting nerve regeneration across a conduit has been extensively reported in the literature, and Schwann cell motility has been acknowledged as a prerequisite for myelination of the peripheral nervous system during regeneration after injury. METHODS: Review of recent literature and retrospective analysis of our studies with genetically modified Schwann Cells with increased motility in order to identify the underlying mechanism of action and outline the future trends in peripheral nerve repair. FINDINGS: Schwann cell transduction with the pREV-retrovirus, for expression of Sialyl-Transferase-X, resulting in conferring Polysialyl-residues (PSA) on NCAM, increases their motility in-vitro and ensures nerve regeneration through silicone tubes after end-to-side neurorraphy in the rat sciatic nerve model, thus significantly promoting fiber maturation and functional outcome. An artificial nerve graft consisting of a type I collagen tube lined with the genetically modified Schwann cells with increased motility, used to bridge a defect in end-to-end fashion in the rat sciatic nerve model, was shown to promote nerve regeneration to a level equal to that of a nerve autograft. CONCLUSIONS: The use of genetically engineered Schwann cells with enhanced motility for grafting endoneural tubes promotes axonal regeneration, by virtue of the interaction of the transplanted cells with regenerating axonal growth cones as well as via the recruitment of endogenous Schwann cells. It is envisaged that mixed populations of Schwann cells, expressing PSA and one or more trophic factors, might further enhance the regenerating and remyelinating potential of the lesioned nerves.

Poland syndrome in a female patient reconstructed by endoscopically assisted technique.

A two-stage, endoscopically assisted technique was used to reconstruct the chest wall and breast deformity in a female patient with Poland syndrome. In the first stage the latissimus dorsi muscle was transferred anteriorly, and a tissue expander was placed under the transposed muscle to adjust the size of the breast accordingly. In the second stage the same incision in the midaxillary line was used to remove the expander and place a permanent implant endoscopically. The two-stage technically demanding endoscopically assisted reconstruction of Poland syndrome was rewarded by inconspicuous scars and a fine aesthetic result.

Experimental isolation and transplantation of hepatocytes with the use of antibody against interleukin-2 receptor (daclizumab) as immunosuppressive agent.

INTRODUCTION: Daclizumab (Dmab) is a genetically engineered humanized IgG1 monoclonal antibody that binds to the alpha chain of the interleukin-2 receptor (Tac, CD25, p55) expressed on activated human T lymphocytes. Dmab has been used in a clinical protocol of islet transplantation with satisfactory results. The aim of the present study was to evaluate the use of an antibody against the interleukin-2 receptor (Dmab) as an immunosuppressive agent in an experimental model of hepatocyte allotransplantation (allo-Tx) in rats with fulminant hepatic failure (FHF). MATERIALS AND METHODS: Six Wistar rats were used as donors and 48 Lewis rats as recipients: four groups of 12 animals each with induction of FHF and 24 hour later hepatocyte Tx--group A: no treatment; group B: cyclosporin (20 mg/kg days 0 to 5 and 10 mg/kg days 6 to 15); group C: Dmab (0.05 mg day of Tx and 0.05 mg day 7); and group D: Dmab and cyclosporine. Hepatocytes were transplanted intrasplenically. Animals were followed for 15 days. RESULTS: Statistical analysis showed better survival among groups C (83%, MST = 13) and D (92%, MST = 14.25) compared to groups A (max 72, MST = 1.5) or B (50%, MST = 9). Survival in group D was better but not significantly than group C. Biochemical evaluation and histology confirmed satisfactory function and engraftment, respectively. CONCLUSION: This experimental model showed the safe, effective use of Dmab.

Use of mycophenolate mofetil in the experimental allo-transplantation of hepatocytes in rats with fulminant hepatic failure.

AIM: The aim of the study was to evaluate the beneficial effect of mycophenolate mofetil (MMF) as an immunosuppressive agent for experimental transplantation of hepatocytes in rats with fulminant hepatic failure (FHF). MATERIALS AND METHODS: Six Wistar rats were used as donors and 40 Lewis rats at recipients, including four groups of 10 animals each. Group A received no treatment; Group B, cyclosporine (20 mg/kg days 0-5 and 10 mg/kg days 6-15); Group C, MMF (12 mg/kg per os every day); and Group D, MMF (23 mg/kg per os every day). Hepatocytes were transplanted intrasplenically. Animals were followed for 15 days. RESULTS: The survival rates for Group A were maximum 72 h, whereas Groups B, C, and D showed 50%, 70%, and 80%, respectively. Biochemical evaluation and histology showed satisfactory function and engraftment, respectively. CONCLUSION: The use of MMF in this experimental model yielded safe, satisfactory immunosuppression especially at the dose of 23 mg/kg.

Microvascular repair with 1-mm polytetrafluoroethylene (PTFE) grafts: effect of recombinant tissue-type plasminogen activator (rt-PA) on the patency rate and healing process.

The present study assesses the effect of recombinant tissue-type plasminogen activator (rt-PA) on the patency rate and healing process of microvascular polytetrafluoroethylene (PTFE) grafts. Wistar rats were used, divided into four groups of 25 animals each. After dissection of the carotid artery a segment of the vessel, 1 cm long, was resected and replaced by equal length graft. Two different type fibril length (30- or 60-microm) grafts of the same wall thickness (0.18 mm) were used. Normal saline or 3 mg/kg of body weight of rt-PA was applied locally in each group of different fibril length grafts. Patency tests were performed at 15 min and 4 weeks after blood flow was reestablished. All grafts were harvested and examined histologically. The results showed that local application of rt-PA improves patency statistically significantly in both types of fibril length grafts. Patency in 60-microm fibril length grafts was statistically significantly higher than that of 30-microm fibril length grafts, whether rt-PA was used or not. The use of rt-PA had no influence on the healing process of either type of graft.