Christian Andreas Radu

Dermal substitution with Matriderm® in burns on the dorsum of the hand

BACKGROUND Dermal substitutes are used increasingly in deep partial and full-thickness burn wounds in order to enhance elasticity and pliability. In particular, the dorsum of the hand is an area requiring extraordinary mobility for full range of motion. The aim of this comparative study was to evaluate intra-individual outcomes among patients with full-thickness burns of the dorsum of both hands. One hand was treated with split-thickness skin grafts (STSG) alone, and the other with the dermal substitute Matriderm(®) and split-thickness skin grafts. MATERIAL AND METHODS In this study 36 burn wounds of the complete dorsum of both hands in 18 patients with severe burns (age 45.1±17.4 years, 43.8±11.8% TBSA) were treated with the simultaneous application of Matriderm(®), a bovine based collagen I, III, V and elastin-hydrolysate based dermal substitute, and split-thickness skin grafting (STSG) in the form of sheets on one hand, and STSG in the form of sheets alone on the other hand. The study was designed as a prospective comparative study. Using both objective and subjective assessments, data were collected at one week and 6 months after surgery. The following parameters were included: After one week all wounds were assessed for autograft survival. Skin quality was measured 6 months postoperatively using the Vancouver Burn Skin Score (VBSS). Range of motion was measured by Finger-Tip-Palmar-Crease-Distance (FPD) and Finger-Nail-Table-Distance (FNTD). RESULTS Autograft survival was not altered by simultaneous application of the dermal matrix (p>0.05). The VBSS demonstrated a significant increase in skin quality in the group with dermal substitutes (p=0.02) compared to the control group with non-substituted wounds. Range of motion was significantly improved in the group treated with the dermal substitute (p=0.04). CONCLUSION From our results it can be concluded that simultaneous use of Matriderm(®) and STSG is safe and feasible, leading to significantly better results in respect to skin quality of the dorsum of the hand and range of motion of the fingers. Skin elasticity was significantly improved by the collagen/elastin dermal substitute in combination with sheet-autografts.

Single-stage Matriderm® and skin grafting as an alternative reconstruction in high-voltage injuries

This article presents a retrospective analysis of a series of nine patients requiring reconstruction of exposed bone, tendons or joint capsules as a result of acute high‐voltage injuries in a single burn centre. As an alternative to free tissue transfer, the dermal substitute Matriderm® was used in a one‐stage procedure in combination with split‐thickness skin grafts (STSG) for reconstruction. Nine patients, in the period between 2005 and 2009 with extensive high‐voltage injuries to one or more extremities which required coverage of exposed functional structures as bone, tendons or joint capsule, were included. A total of 11 skin graftings and 2 local flaps were performed. Data including regrafting rate, complications, hospital stays, length of rehabilitation and time until return to work were collected. Eleven STSG in combination with Matriderm® were performed on nine patients (success rate 89%). One patient died. One patient needed a free‐flap coverage as a secondary procedure. The median follow‐up was 30 months (range 6–48 months). The clinical results of these nine treated patients concerning skin‐quality and coverage of exposed tendons or joint capsule were very good. In high‐voltage injuries free‐flap failure occurs between 10% and 30% if performed within the first 4–6 weeks after trauma. The use of single‐stage Matriderm® and skin grafting for immediate coverage described in this article is a reliable alternative to selected cases within this period.

Antiseptic therapy with a polylacticacid-acetic acid matrix in burns

Bacterial colonization and infection are still the major causes of delayed healing and graft rejection following burns and they are furthermore the basis for second and third hit sepsis. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD‐Ag) is a frequently used microbicidal agent. However, this treatment causes adverse reactions and side‐effects. Additionally, in recent years multiresistant bacteria, which have not been treated sufficiently, are on the rise. On the basis of experimental data and clinical application of a polylacticacid–acetic acid matrix, we performed this study to establish the effectiveness of the antiseptic therapy with the topical application of a polylacticacid–acetic acid matrix to provide an alternative method for burn treatment, using SD‐Ag as a reference. Twenty patients with IIb° or III° burns from the Plastic Surgery and Burns Unit were treated within a matched pair comparative setting. One burned area was treated with SD‐Ag, the other corresponding area with the polylacticacid–acetic acid matrix. All patients underwent a necrectomy 4–5 days after the trauma. The excised burned skin was sent to our microbiological laboratory to determine the different bacteria per gram in this tissue. Despite the number of 20 patients, statistical significance was not achieved, there were tendencies to a better antiseptic effectiveness of the polylacticacid–acetic acid matrix. These results suggest that the polylacticacid–acetic acid matrix should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns, as it is equivalent or even more effective than SD‐Ag.

Immunosuppressive effect of tryptophan metabolites in composite tissue allotransplantation

Background: Hand transplantations have intensified immunological research into composite tissue allotransplantation to induce tolerance. Pregnancy is a successful, natural model of immunological tolerance. The enzyme indoleamine 2,3-deoxygenase plays an important role by catabolizing the amino acid tryptophan. The resulting metabolites have been shown to be immunosuppressive. The effect of tryptophan metabolites has not been investigated in vascularized organ transplantation before. In this study, the authors applied to composite tissue allotransplantation what nature has developed for pregnancy, and examined the immunosuppressive effect of tryptophan metabolites in a model of hind limb transplantation. Methods: Thirty-three allogeneic hind limb transplantations in the rat (Lewis → Brown-Norway) were performed in three groups. Group A (n = 12) received no immunosuppression, group B (n = 13) received tryptophan metabolites (kynurenine and 3-hydroxyanthranilic acid) locally and systemically, and group C (n = 8) served as a control group receiving FK506. The timing of rejection was assessed by clinical observation. Results: Rejection of the allogeneic hind limb occurred on average 6.58 days after transplantation in group A (no immunosuppression) and after 8.15 days in group B (tryptophan metabolites). Rejection was significantly delayed (log-rank test, p < 0.01). No rejection was seen with application of FK506 during the follow-up period of 21 days. Conclusions: For the first time, tryptophan metabolites have been applied in vascularized composite tissue allotransplantation and showed a significant immunosuppressive effect. These promising first results need further dose-effect and toxicological studies to increase the still limited immunosuppressive effect and define the clinical role these metabolites may play in the future.

Optimizing Suprathel®-therapy by the use of Octenidine-Gel®

OBJECTIVE A prospective, randomized, non-blinded, clinical study was conducted to evaluate the feasibility and practicability as well as pain reduction and ease of handling of Flammazine® versus Octenidine-Gel® s a primary local antiseptic before synthetic skin substitute application in partial-thickness burns. METHODS Thirty patients with a median age of 42 years suffering from second-degree burns were included in the study. Burns were randomly selected, one area was treated with Flammazine®/gauze, another area in the same patient was treated with Octenidine-Gel®/gauze as initial antiseptic treatment. Within 24 h the first gauze change was performed followed by wound inspection, disinfection and synthetic skin substitute application. The study focused on patient pain score, analysis of wound bed and ease of handling of the two local antiseptic agents. RESULTS There was a significant difference between Flammazine® versus Octenidine-Gel® regarding patient pain score and ease of handling. Octenidine-Gel® was less painful (p < 0.05) and easier to handle (p < 0.05). There was no significant difference for wound bed evaluation between the two antiseptic agents. A tendency for better wound bed preparation was seen with the use of Octenidine-Gel®. CONCLUSION Based on the findings of this study Octenidine-Gel® is recommended as a local antiseptic agent, because when compared to Flammazine®, Octenidine-Gel® proved to be better in terms of ease of care, simplicity application, with gentler and faster detachment of the gel from wound surfaces and consequently far less pain during dressing changes.

Haemodynamically stimulated and in vivo generated axially vascularized soft‐tissue free flaps for closure of complex defects: Evaluation in a small animal model

The arteriovenous (AV) loop model permits the creation of significant volumes of axially vascularized tissue that represents an alternative to conventional free flaps, circumventing their common limitations. However, such AV loop‐based flaps have never before been examined in standardized animal models with respect to their suitability for reconstruction of critical bone‐exposing defects. In the course of our preliminary studies, we implemented a novel defect model in rats that provides standardized and critical wound conditions and evaluated whether AV loop‐generated flaps are suitable for free microsurgical transfer and closure of composite defects. We compared three groups of rodents with similar scapular defects: one received the AV flap, whereas controls were left to heal by secondary intention or with supplementary acellular matrix alone. To create the flaps, AV loops were placed into subcutaneous Teflon chambers filled with acellular matrix and transferred to the thigh region. Flap maturation was evaluated by histological analysis of angiogenesis and cell migration at days 14 and 28 after loop creation. Flap transfer to the scapular region and microsurgical anastomoses were performed after 14 days. Postoperative defect closure and perfusion were continually compared between groups. Within the AV flap chamber, the mean vessel number, cell count and the proportion of proliferating cells increased significantly over time. The novel defect model revealed that stable wound coverage with homogeneous vascular integration was achieved by AV loop‐vascularized soft‐tissue free flaps compared with controls. In summary, our study indicates for the first time that complex composite defects in rats can successfully be treated with AV loop‐based free flaps.

Domestic bioethanol-fireplaces–a new source of severe burn accidents

BACKGROUND Bioethanol-fueled fireplaces are popular interior home decoration accessories. Although their safety is promoted frequently, actual presentations of severe burn injuries in our burn intensive care unit (ICU) have focused the authors on safety problems with these devices. In this article we want to explore the mechanisms for these accidents and state our experiences with this increasingly relevant risk for severe burn injuries. MATERIALS AND METHODS The computerized medical records of all burn intensive care patients in our burn unit between 2000 and 2014 were studied. Since 2010, 12 patients with bioethanol associated burn injuries were identified. Their data was compared to the values of all patients, except the ones injured by bioethanol fireplaces that presented themselves to our burn ICU between the years 2010 and 2014. RESULTS At time of admission the bioethanol patients had a mean ABSI-score of 4.8 (+/- 2.2 standard deviation (SD)). A mean of 17 percent (+/- 9.1 SD) body surface area was burned. Involvement of face and hands was very common. An operative treatment was needed in 8 cases. A median of 20 days of hospitalization (range 3-121) and a median of 4.5 days on the ICU (range 1-64) were necessary. No patient died. In most cases the injuries happened while refilling or while starting the fire, even though safety instructions were followed. In the control group, consisting of 748 patients, the mean ABSI-score was 5.6 (+/- 2.7 SD). A mean of 16.5 percent (+/- 10.1 SD) body surface area was burned. Treatment required a median of 3 days on the burn ICU (range 1-120). Regarding these parameters, the burden of disease was comparable in both groups. CONCLUSION Bioethanol-fueled fireplaces for interior home decoration are a potential source for severe burn accidents even by intended use.

Long-Term Outcome after Successful Lower Extremity Free Flap Salvage

Background Vascular occlusion after free flap surgery has become a rare complication but still poses a major challenge. It necessitates urgent re‐exploration, but the logistic challenge to provide sufficient resources for the emergency intervention remains. The aim of this study was to analyze the long‐term outcome after successful lower extremity free flap salvage. Methods A single‐center retrospective study including long‐term follow‐up was approved by the local ethics committee. From January 1999 to December 2010, a total of 581 free flaps were performed for lower extremity reconstruction. Eighty‐six flaps required emergency re‐exploration, of which 65 could be salvaged. Fifteen salvaged flaps were excluded from the study because of secondary amputation. Of 50 patients, 29 (6 females and 23 males) were eligible for follow‐up. The mean follow‐up time was 54.5 ± 32.9 months. Health‐related quality of life (Short Form 36 [SF‐36]) and scar quality (Vancouver Scar Scale [VSS]) were analyzed. Results The overall flap survival rate was 94.7% and the total loss rate was 5.3%. The re‐exploration rate was 14.8% (86 of 581 flaps). The salvage rate was 75.6% (65 of 86 flaps). Twenty‐one free flaps were totally lost (24.4%). Partial flap loss occurred in 12 cases (14.0%); 67.5% of the vascular complications occurred during the first 24 hours, 20.9% between 24 and 72 hours, and 11.6% after more than 72 hours. The mean time from the first signs of impaired flap perfusion to re‐exploration was 1.3 ± 0.4 hours, and from free tissue transfer to re‐exploration was 16.2 ± 1.9 hours. The overall scar appearance was good with an average VSS score of 4.0 points. The average SF‐36 physical component score was 54.4 ± 5.4 and the mental component score was 63.1 ± 10.7. Conclusion Careful monitoring and the opportunity for urgent re‐exploration are the key to success for free flaps salvage. Following these principles, an acceptable long‐term outcome can be achieved.