Guenter Germann

A realistic complication analysis of 70 sural artery flaps in a multimorbid patient group.

The popularity of the sural artery flap has increased markedly throughout the years, and favorable results are reported almost uniformly. Previous publications have mainly presented results of small groups and of predominantly younger patients with posttraumatic defects, or they have reported technical modifications of the sural artery flap. The authors have increasingly used the reversed sural artery flap in a high-risk, critically multimorbid, and older patient population, and in contrast to the results of other authors, a considerable necrosis rate of 36 percent was seen. For the first time, a detailed, critical, retrospective complication analysis of 70 sural artery flaps is presented. The results reveal the following risk factors, which can potentially impair successful defect coverage and thus contribute to flap complications: concomitant diseases, particularly diabetes mellitus; peripheral arterial disease or venous insufficiency, which increase the risk of flap necrosis five-fold to six-fold; and patient age of over 40 years, because of an increased rate of comorbidity, underlying osteomyelitis, and the use of a tight subcutaneous tunnel. However, age alone did not seem to represent a risk factor by itself. Given the results of the analysis, the operative procedure was altered, as follows. In cases in which a lesser saphenous vein cannot be found, a delay procedure is recommended, or the flap is not utilized. In addition, an external fixation device seems to facilitate postoperative care markedly without adding specific complications; it is recommended in most patients. This analysis emphasizes specific risk factors that result in higher complication rates of the sural artery flap, and it leads to more realistic and appropriate expectations for this flap.

Soft tissue coverage in devastating hand injuries

Plastic surgical therapy of mutilating hand injuries represents a multifaceted task to the hand surgeon, where considerations about indication, timing, and structure of the soft tissue coverage play a major role in reconstruction. The concept of early primary reconstruction (including emergency procedures) and fast rehabilitation not only demands thoughtful tissue preparation but also mastering of a bandwidth of plastic surgical techniques. Systematic algorithms based on the reconstructive ladder help in decision making in the complexity of soft tissue coverage but have to be adjusted to the individual case profile. General considerations and strategic planning are explained and illustrated by three clinical cases.

Customized reconstruction with the free anterolateral thigh perforator flap

From April of 2003 through September of 2006, 70 free anterolateral thigh (ALT) flaps were transferred for reconstructing soft‐tissue defects. The overall success rate was 96%. Among 70 free ALT flaps, 11 were elevated as cutaneous ALT septocutaneous vessel flaps. Fifty‐seven were harvested as cutaneous ALT myocutaneous “true” perforator flaps. Two flaps were used as fasciocutaneous perforator flaps based on independent skin vessels. Fifty‐four ALT flaps were used for lower extremity reconstruction, 11 flaps were used for upper extremity reconstruction, 3 flaps were used for trunk reconstruction, and 1 flap was used for head and neck reconstruction. Total flap failure occurred in 3 patients (4.28% of the flaps), and partial failure occurred in 5 patients (7.14% of the flaps). The three flaps that failed completely were reconstructed with a free radial forearm flap, a latissimus dorsi flap and skin grafting, respectively. Among the five flaps that failed partially, three were reconstructed with skin grafting, one with a sural flap, and one with primary closure. The free ALT flap has become the workhorse for covering defects in most clinical situations in our center. It is a reliable flap with consistent anatomy and a long, constant pedicle diameter. Its versatility, in which thickness and volume can be adjusted, leads to a perfect match for customized reconstruction of complex defects.

Restoration of thumb sensibility with the innervated first dorsal metacarpal artery island flap

PURPOSE This study investigated the quality of sensibility from innervated first dorsal metacarpal artery (FDMCA) island flaps in younger and older patients and evaluated the donor site morbidity at the index finger. METHODS Twenty-five patients with an innervated FDMCA island flap to restore sensibility of the thumb were divided into groups according to age (>50 or <50 years). Sensory recovery and cortical reorientation were tested with Semmes-Weinstein monofilaments, a calibrated 2-point discrimination tester, and needle prick testing. Donor site morbidity was evaluated for range of motion, aesthetic appearance, pain, and problems with injuries. RESULTS The mean age of the patients was 48.3 years and the mean follow-up period was 3 years. The 14 patients older than 50 years had a static 2-point discrimination (s2-PD) of 10.9 mm compared with 10.8 mm of the 11 patients younger than 50 years. The average loss of s2-PD of the flap compared with the donor area averaged 2.7 mm in all patients. Complete cortical reorientation occurred in 7 patients older than 50 years and in 5 patients younger than 50 years. Total loss of range of motion of all donor finger joints was 14 degrees (4.4%) compared with the contralateral index finger. Twenty-two patients were satisfied with the result. CONCLUSIONS There were no age-related differences in the surgical results of the innervated FDMCA island flap and the donor site morbidity was negligible.

A liposome hydrogel with polyvinyl-pyrrolidone iodine in the local treatment of partial-thickness burn wounds.

Local treatment of burn injuries with conventional anti-infective preparations does not provide the moist environment that promotes fast wound healing. In a randomized controlled trial the effects of liposome polyvinyl-pyrrolidone-iodine (PVP-I) hydrogel, a novel formulation of PVP-I in a liposome hydrogel with high water-binding capacity, were investigated in 43 patients with partial-thickness burn wounds in an intraindividual comparison with a conventional silver-sulfadiazine cream. Treatment with liposome PVP-I hydrogel resulted in significantly faster complete healing of the burn wounds compared with silver-sulfadiazine cream (9.9 ± 4.5 days versus 11.3 ± 4.9; P < 0.015). The cosmetic result (smoothness, elasticity, appearance) was rated as excellent for 37.0% of study wounds with liposome PVP-I hydrogel compared with 13.0% of wounds treated with silver-sulfadiazine cream. Local tolerability was good; handling and change of dressing were rated as easy. Local treatment with liposome PVP-I hydrogel thus provides fast wound healing with a favorable cosmetic result.

High-dose vitamin C treatment reduces capillary leakage after burn plasma transfer in rats.

Oxidative stress after burn injuries leads to systemic capillary leakage and leukocyte activation. This study evaluates whether antioxidative treatment with high-dose vitamin C leads to burn edema reduction and prevention of leukocyte activation after burn plasma transfer. Donor rats underwent a burn (n = 7; 100°C water, 12 seconds, 30% body surface area) or sham burn (37°C water; n = 2) procedure and were killed after 4 hours for plasma harvest. This plasma was administered to study rats (continuous infusion). Rats were randomized to four groups (n = 8 each; burn plasma alone [BP]; burn plasma/vitamin C-bolus 66 mg/kg and maintenance dose 33 mg/kg/hr [VC66]; burn plasma/vitamin C-bolus 33 mg/kg and maintenance dose 17.5 mg/kg/hr [VC33]; and sham burn plasma [SB]). Intravital fluorescence microscopy in the mesentery was performed at 0, 60, and 120 minutes for microhemodynamic parameters, leukocyte adherence, and fluorescein isothiocyanate-albumin extravasation. No differences were observed in microhemodynamics at any time. Burn plasma induced capillary leakage, which was significantly higher compared with sham burn controls (P < .001). VC66 treatment reduced microvascular barrier dysfunction to sham burn levels, whereas VC33 had no significant effect. Leukocyte sticking increased after burn plasma infusion, which was not found for sham burn. Vitamin C treatment did not influence leukocyte activation (P > .05). Burn plasma transfer leads to systemic capillary leakage. High-dose vitamin C treatment (bolus 66 mg/kg and maintenance dose 33 mg/kg/hr) reduces endothelial damage to sham burn levels, whereas half the dose is inefficient. Leukocyte activation is not influenced by antioxidative treatment. Therefore, capillary leakage seems to be independent from leukocyte-endothelial interactions after burn plasma transfer. High-dose vitamin C should be considered for parenteral treatment in every burn patient.

Effect of arteriovenous flow reversal on blood flow and metabolism in a skin flap.

Twelve pig buttock island flaps (10 X 10 cm) were studied for 6 hours after arteriovenous flow reversal at the level of the pedicle. Follow-up was 48 hours. Blood pressure, Po2, pH, and lactate were measured in flap arteries and veins. Oxygen consumption was calculated. Data indicated true flow reversal. Blood pressure and Po2 in flap veins increased to systemic arterial levels. Outflow was provided by the arterial system, demonstrating venous pressure and Po2 values. Lactate increased significantly (1.8 +/- 0.5 to 4.0 +/- 2.3 mmol/liter), while pH dropped from 7.43 +/- 0.03 to 7.11 +/- 0.02. Oxygen consumption remained below baseline. In four flaps thrombosis occurred within 6 hours; no flap survived 48 hours. The results of this study do not encourage clinical application of the concept of flow reversal.

Correlation of Ulnar Length and Apoptotic Cell Death in Degenerative Lesions of the Triangular Fibrocartilage

PURPOSE The purpose of this study was to investigate apoptosis in degenerative disc lesions (Palmer type IIC) and differentiate between patients with ulna-plus and ulna-neutral variance. METHODS Seventeen patients with degenerative tears (Palmer type IIC) in the articular disc of the triangular fibrocartilage were included in this study. The triangular fibrocartilage was debrided arthroscopically with a punch and the histologic sections were used to analyze necrosis and apoptosis. Apoptosis and necrosis was quantified by terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay. Apoptotic cells were visualized by poly(ADP-ribose) polymerase (PARP) p85 immunohistochemistry. The number of apoptotic and necrotic cells was then correlated with ulnar length. RESULTS PARP- and TUNEL-positive cells were found in each patient. In addition, patients with an ulna plus variance showed a significantly increased number of apoptotic cells in comparison to patients with an ulna neutral variance. The distribution of the apoptosis-positive cells did not show any accumulation in the inner part of the specimen, but were evenly distributed. CONCLUSIONS This study showed that patients with ulna plus present with significantly higher numbers of apoptotic cells in degenerative lesions in comparison to patients with ulna neutral. The apoptotic cells were evenly distributed throughout the entire specimen. CLINICAL RELEVANCE The results of this study revealed that increased length of the ulna is related to increased cell death. Therefore, techniques that decrease the ulna variance would appear to be appropriate and would improve the clinical situation by preventing further cell death.

Human Adipose Tissue Derived Stem Cells Promote Liver Regeneration in a Rat Model of Toxic Injury

In the light of the persisting lack of donor organs and the risks of allotransplantations, the possibility of liver regeneration with autologous stem cells from adipose tissue (ADSC) is an intriguing alternative. Using a model of a toxic liver damage in Sprague Dawley rats, generated by repetitive intraperitoneal application of retrorsine and allyl alcohol, the ability of human ADSC to support the restoration of liver function was investigated. A two-thirds hepatectomy was performed, and human ADSC were injected into one remaining liver lobe in group 1 (n = 20). Injection of cell culture medium performed in group 2 (n = 20) served as control. Cyclosporine was applied to achieve immunotolerance. Blood samples were drawn weekly after surgery to determine liver-correlated blood values. Six and twelve weeks after surgery, animals were sacrificed and histological sections were analyzed. ADSC significantly raised postoperative albumin (P < 0.017), total protein (P < 0.031), glutamic oxaloacetic transaminase (P < 0.001), and lactate dehydrogenase (P < 0.04) levels compared to injection of cell culture medium alone. Transplanted cells could be found up to twelve weeks after surgery in histological sections. This study points towards ADSC being a promising alternative to hepatocyte or liver organ transplantation in patients with severe liver failure.

Alterations of gene expression and protein synthesis in co-cultured adipose tissue-derived stem cells and squamous cell-carcinoma cells: consequences for clinical applications

IntroductionThis is the first study evaluating the interactions of human adipose tissue derived stem cells (ADSCs) and human squamous cell carcinoma cells (SCCs), with regard to a prospective cell-based skin regenerative therapy and a thereby unintended co-localization of ADSCs and SCCs.MethodsADSCs were co-cultured with A431-SCCs and primary SCCs (pSCCs) in a transwell system, and cell-cell interactions were analyzed by assessing doubling time, migration and invasion, angiogenesis, quantitative real time PCR of 229 tumor associated genes, and multiplex protein assays of 20 chemokines and growth factors and eight matrix metalloproteinases (MMPS). Results of co-culture were compared to those of the respective mono-culture.ResultsADSCs’ proliferation on the plate was significantly increased when co-cultured with A431-SCCs (P = 0.038). PSCCs and ADSCs significantly decreased their proliferation in co-culture if cultured on the plate (P <0.001 and P = 0.03). The migration of pSCC was significantly increased in co-culture (P = 0.009), as well as that of ADSCs in A431-SCC-co-culture (P = 0.012). The invasive behavior of pSCCs and A431-SCCs was significantly increased in co-culture by a mean of 33% and 35%, respectively (P = 0.038 and P <0.001). Furthermore, conditioned media from co-cultured ADSC-A431-SCCs and co-cultured ADSCs-pSCCs induced tube formation in an angiogenesis assay in vitro.In A431-SCC-co-culture 36 genes were up- and 6 were down-regulated in ADSCs, in A431-SCCs 14 genes were up- and 8 genes were down-regulated. In pSCCs-co-culture 36 genes were up-regulated in ADSCs, two were down-regulated, one gene was up-regulated in pSCC, and three genes were down-regulated. Protein expression analysis revealed that three proteins were exclusively produced in co-culture (CXCL9, IL-1b, and MMP-7). In A431-SCC-co-culture the concentration of 17 proteins was significantly increased compared to the ADSCs mono-culture (2.8- to 357-fold), and 15 proteins were expressed more highly (2.8- to 1,527-fold) compared to the A431-SCCs mono-culture. In pSCC-co-culture the concentration of 10 proteins was increased compared to ADSCs-mono-culture (2.5- to 77-fold) and that of 15 proteins was increased compared to pSCC mono-culture (2.6- to 480-fold).ConclusionsThis is the first study evaluating the possible interactions of primary human ADSCs with human SCCs, pointing towards a doubtlessly increased oncological risk, which should not be neglected when considering a clinical use of isolated human ADSCs in skin regenerative therapies.