Is there a need for postoperative monitoring after open carpal tunnel release under WALANT?

Open carpal tunnel release (OCTR) under wide-awake local anesthesia with no tourniquet (WALANT) is a common outpatient procedure in hand surgery worldwide. In our clinic, WALANT has replaced intravenous regional anesthesia with a tourniquet (IVRA, or 'Bier block') as standard practice in OCTR. We therefore wondered what the optimal postoperative setting after OCTR under WALANT is. In this study, we compared patient satisfaction in two postoperative settings: immediate discharge (ID) after the operation, or short postoperative monitoring (PM) period in the outpatient clinic. Our hypothesis was that older patients would prefer a brief postoperative surveillance. We retrospectively analyzed patient satisfaction with the two settings using an adjusted questionnaire based on the standard Swiss grading system. We also assessed postoperative pain, satisfaction with the perioperative preparations and the reasons for unscheduled postoperative consultations, as secondary outcomes. One hundred and nine patients (ID, n = 63; PM, n = 46) were included in this single-center retrospective observational study. Patients were highly satisfied with both postoperative settings (Mean: ID 5.1/6; PM 5.5/6; p = 0.07). Even patients aged ≥80 years reported extremely high satisfaction with both settings (ID 5.6/6; PM 6.0/6; p = 0.08). Fifteen patients (ID, n = 11 [17.5%]; PM, n = 4 [8.7%], p = 0.72) unexpectedly consulted a doctor after surgery. OCTR under WALANT as an outpatient procedure with immediate discharge was associated with high patient satisfaction. However, detailed postoperative monitoring could contribute to the patient's well-being and education on how to cope with the postoperative course, and help with any questions.

[Isolation and Characterization of Multipotent Precursor Cells from Murine Adipose Tissue using a Clinically Approved Cell Separation System]. / Isolation und Charakterisierung von multipotenten Vorläuferzellen aus murinem Fettgewebe mithilfe eines klinisch zugelassenen Aufbereitungssystems.

INTRODUCTION: Recent studies underscored the clinical potential of adipose-derived multipotent stem-/precursor cells (ASPCs). One of the main hurdles en route to clinical application was to isolate cells without having to perform expansion cultures outside the OR. A new generation of clinically approved, commercially available cell separation systems claims to provide ASPCs ready for application without further expansion cultures. However, it is unclear if the new systems yield sufficient cells of adequate quality for the use in autologous murine models. The aim of this study was to isolate and characterize adipose-derived precursor cells taken from the inguinal fat pat of wistar rats using InGeneron's clinically approved ARC™-cell separation system. MATERIALS AND METHODS: We isolated cells from the inguinal fat pad of 3 male Wistar rats according to the manufacturer's protocol. In order to reduce the influence of the atmospheric oxygen on the multipotent precursor cells, one half of the cell suspension was cultivated under hypoxia (2% O2) simulating physiological conditions for ASPCs. As a control, the other half of the cells were cultivated under normoxia (21% O2). Cell surface markers CD90, CD29, CD45 and CD11b/c were analyzed by FACS, and osteogenic and adipogenic differentiation of the ASPCs was performed. Finally, cellular growth characteristics were assessed by evaluation of the cumulative population doublings and CFU assay, and metabolic activity was evaluated by WST-1 assay. RESULTS: Processing time was 90 (± 12) min. 1 g of adipose tissue yielded approximately 60 000 plastic adhering cells. Both groups showed a high expression of the mesenchymal stem cell markers CD90 and CD29 while they were negative for the leucocyte markers CD45 and CD11b/c. A strong osteogenic differentiation and a sufficient adipogenic differentiation potential was proven for all ASPCs. Under hypoxia, ASPCs showed increased proliferation characteristics and CFU efficiency as well as a significantly increased metabolic activity. CONCLUSION: This study showed that sufficient multipotent ASPCs of appropriate quality can be isolated from the inguinal fat pad of Wistar rats using the ARC™-cell separation system. As shown in previous studies, cultivation of cells under hypoxic conditions increased their stemness. Our findings will enable future studies that focus on autologous transplantation of ASPCs in a rat model, which most closely resembles a possible clinical application.

[Results after Arthroscopically Assisted Management of Intra-Articular Distal Radius Fractures]. / Ergebnisse nach arthroskopisch assistiert versorgter distaler Radiusfraktur mit Gelenkbeteiligung.

UNLABELLED: Background/Goal: An arthroscopically assisted management of intra-articular distal radius fractures may improve the quality of reduction. Furthermore, concomitant ligament and triangular fibrocartilage complex injuries can be identified and treated. However, this approach increases the duration of surgery. If severe soft tissue lesions, such as SL-ligament disruptions are treated simultaneously, a longer post-operative immobilisation will be required. The aim of this study was to measure the clinical outcome one year after arthroscopically assisted treatment of intra-articular distal radius fractures. PATIENTS AND METHODS: In a retrospective study from 2011 to 2013 we identified 27 patients with intra-articular distal radius fractures who were treated with volar fixed angle plates in an arthroscopically assisted fashion. The amount of associated injuries, the duration of surgery and the time of immobilisation were documented. One year postoperatively we evaluated 23 of these patients using several scores. Patient satisfaction, range of motion, visual analogue scale and grip strength were assessed using a standardised questionnaire. RESULTS: The mean surgery time was 111 min (60-190 min). On average, we found 1.4 (0-3) associated injuries per patient. Seventy percent (19) of all patients had a triangular fibrocartilage complex lesion, 67% (16) had some degree of scapholunate ligament lesion. The mean number of interventions in addition to the plate fixation was 1.1 per patient (0-3). Among these were debridements of the triangular fibrocartilage complex in 11 cases (41%) and scapholunate ligament repairs in 4 cases (15%). The mean immobilisation time was 22 (0-42) days. At one year after surgery, the mean Mayo wrist score was 79 (65-95) and the DASH score was 12 (0-49). CONCLUSION: The arthroscopically assisted management of intra-articular distal radius fractures helps to identify and treat associated injuries. However, it results in extended surgery and immobilisation time, especially if concomitant intra-articular lesions are treated. In our group of patients, the clinical outcome after one year was nonetheless very good.

[Interrater Reliability of Scapholunate Advanced Collapse (SLAC) Wrist Stage Classification and Influence of Diagnostic Wrist Arthroscopy]. / Interrater-Reliabilität der Schweregradeinteilung des karpalen Kollapses bei skapholunärer Dissoziation und Einfluss der Handgelenksarthroskopie.

AIM: Therapy of scapholunate advanced collapse (SLAC) wrist should be guided by the degree of arthritic changes within the radioscaphoid and midcarpal joints (stage 1-3 after Watson). Diagnostic investigations usually include X-ray imaging and wrist arthoscopy. In the present study, the interrater reliability of SLAC wrist stage classification by means of X-ray image analysis was evaluated between radiologists and hand surgeons. Ultimately, the influence of diagnostic wrist arthroscopy on the final stage classification was determined. PATIENTS AND METHODS: Retrospectively, 38 SLAC wrists of 37 patients were included in this study. Conventional X-ray images in a dorso-palmar and lateral view were performed before diagnostic wrist arthroscopy. The degree of carpal collapse on X-rays was determined by 2 radiologists and 2 surgeons (1 board certified hand surgeon, 1 plastic surgeon, both experienced in hand surgery since years). After 14 days the stages were re-evaluated by the surgeons with the digital images from the wrist arthroscopies at hand. RESULTS: While the interrater reliability turned out to be 'weak' amidst the radiologists, it was classified as 'light' among the surgeons. We found a 'weak' and a 'light' interrater reliability between the surgeons and the radiologists. Radiologists tended to assess the degree of severity higher than surgeons. The additional knowledge of the digital arthroscopy images led to a different classification in 55%. When X-rays were assessed in combination with the arthroscopy findings, both stage 1 and stage 3 were diagnosed less frequently. CONCLUSIONS: Our study suggests that interpreting X-ray films alone is an unreliable method to assess the stage of SLAC wrist. We believe that additional diagnostic measures such as wrist arthroscopy are needed to accurately diagnose the SLAC wrist stage.

[Free Gracilis Flap for Anatomic Reconstruction after Limb-sparing Sarcoma Resection]. / Freie M. gracilis-Lappenplastik zur anatomischen Rekonstruktion nach gliedmaßen-erhaltender Weichteil-Sarkom Resektion.

INTRODUCTION: Limb-sparing surgery is considered as first choice in most patients with soft tissue sarcomas of the extremities. 5-year survival rates after limb soft tissue sarcoma resection have been promising in many specalised interdisciplinary centres. Quality of life as well as extremity function have thus become an integral aspect of the surgical management of soft tissue sarcomas of the extremities. OBJECTIVE: We herein report on our experience in the anatomic reconstruction of the extremities following limb-sparing soft tissue sarcoma resection using microvascular gracilis muscle flap and skin grafts. PATIENTS AND METHODS: Between 2012 and 2014 an anatomic reconstruction of the hand and foot using gracilis muscle flaps following limb-sparing sarcoma resection (leiomyosarcoma N=2, myxofibrosarcoma N=2, clear cell sarcoma N=1, myxoinflammatory fibroblastic sarcoma N=1, granular cell tumour N=1, pleomorphic sarcoma N=1) was performed in N=8 patients (4 females, 4 males), average age: 44 years (23-76 years), average follow-up time 444 days (98-820). RESULTS: In all patients successful defect coverage with unimpaired wound healing was achieved (adjunctive radiotherapy n=4). The tendon of the harvested gracilis muscle was used for anatomic reconstruction of consequently resected essential anatomic structures (extensor retinaculum n=1, flexor/extensor tendons n=4, extensor expansion n=2, tendon reinsertion n=1, proximal interphalangeal joint collateral ligament n=4, dorsal metatarsal ligament n=1). During follow-up neither local recurrence nor metastasis was observed. CONCLUSION: Reconstruction of multidirectional stability as well as restoring biomechanics and kinetics of the hand and foot should be considered during defect coverage and dead space obliteration management after sarcoma resection of the extremities. For reasons of sound options in anatomic extremity reconstruction with minimal donor site morbidity, the gracilis muscle flap excels in the field of limb-sparing sarcoma resection.

Protective effects of activated protein C (APC) on free groin flaps after secondary venous stasis in the rat model.

BACKGROUND: The goal of this study was to determine whether the focused delivery of APC by rinsing of free adipocutaneous groin flaps shows protective effects on flap survival following a fatal secondary venous stasis in a rat model. METHODS: 36 Sprague Dawley rats were randomized to three groups and free microvascular groin flaps were transplanted to the neck in each animal. 20 hours postoperatively the flap pedicle was re-explored and the distal stump of the flap artery was catheterised. Animals in group I (n = 12) remained untreated, whereas animals of group II were treated with 1 ml of Ringer's solution. Those in group III received 1 ml of APC (2 mg/kg). Afterwards the flap vein was clamped for 35 minutes. The skin of the flaps and the native contralateral groin was examined by intravital video microscopy using FITC-Dextran and CFDA-SE-labelled thrombocytes. RESULTS: APC-pretreatment significantly increased the functional capillary density (FCD) of the flaps. Flap viability was 8% in group I (n = 1/12), 9% in group II (n = 1/11) and 60% in group III (n = 6/10), respectively. No partial flap loss was detected. CONCLUSIONS: The focused delivery of APC resulted in significantly improved flap salvage.

[3D-imaging and analysis for plastic surgery by smartphone and tablet: an alternative to professional systems?]. / 3D Bilderfassung und Analyse in der Plastischen Chirurgie mit Smartphone und Tablet: eine Alternative zu professionellen Systemen?

BACKGROUND: A new approach of using photographs from smartphones for three-dimensional (3D) imaging was introduced besides the standard high quality 3D camera systems. In this work, we investigated different capture preferences and compared the accuracy of this 3D reconstruction method with manual tape measurement and an established commercial 3D camera system. METHODS: The facial region of one plastic mannequin head was labelled with 21 landmarks. A 3D reference model was captured with the Vectra 3D Imaging System®. In addition, 3D imaging was executed with the Autodesk 123d Catch® application using 16, 12, 9, 6 and 3 pictures from Apple® iPhone 4 s® and iPad® 3rd generation. The accuracy of 3D reconstruction was measured in 2 steps. First, 42 distance measurements from manual tape measurement and the 2 digital systems were compared. Second, the surface-to-surface deviation of different aesthetic units from the Vectra® reference model to Catch® generated models was analysed. For each 3D system the capturing and processing time was measured. RESULTS: The measurement showed no significant (p>0.05) difference between manual tape measurement and both digital distances from the Catch® application and Vectra®. Surface-to-surface deviation to the Vectra® reference model showed sufficient results for the 3D reconstruction of Catch® with 16, 12 and 9 picture sets. Use of 6 and 3 pictures resulted in large deviations. Lateral aesthetic units showed higher deviations than central units. Catch® needed 5 times longer to capture and compute 3D models (average 10 min vs. 2 min). CONCLUSION: The Autodesk 123d Catch® computed models suggests good accuracy of the 3D reconstruction for a standard mannequin model, in comparison to manual tape measurement and the surface-to-surface analysis with a 3D reference model. However, the prolonged capture time with multiple pictures is prone to errors. Further studies are needed to investigate its application and quality in capturing volunteer models. Soon mobile applications may offer an alternative for plastic surgeons to today's cost intensive, stationary 3D camera systems.

[Optimising care structures for severe hand trauma and replantation and chances of launching a national network]. / Über Versorgungsstrukturen und Möglichkeiten der Optimierung durch Vernetzung bei schweren Handverletzungen und Replantationen.

Severe hand traumata have a significant impact on our health system and on insurance companies, respectively. It is estimated that 33% of all occupational injuries and 9% of all invalidity pensions are due to severe hand trauma. Unfortunately, these high numbers are not only due to the severity of the trauma but to organisational deficiencies. Usually, the patient is treated at the general surgical emergency in the first place and only then forwarded to a microsurgeon. This redirection increases the time that is required for the patient to finally arrive at an expert for hand surgery. On the one hand, this problem can be explained by the population's lack of awareness for distinguished experts for hand and microsurgery, on the other hand, the emergency network, or emergency doctors in particular are not well informed about where to take a patient with a severe hand trauma - clearly a problem of communication between the hospitals and the ambulance. It is possible to tackle this problem, but put participating hand trauma centres have to work hand in hand as a network and thus exploit synergy effects. The French system "FESUM" is a good example for such a network and even comprises centres in Belgium and Switzerland. To improve the treatment of severe hand trauma, a similar alliance was initiated in Germany just recently. The pilot project "Hand Trauma Alliance" (www.handverletzung.com) was started in April 2013 and currently comprises two hospitals within the region of upper Bavaria. The network provides hand trauma replantation service on a 24/7 basis and aims at shortening the way from the accident site to the fully qualified hand surgeon, to improve the therapy of severe hand injuries and to optimise acute patient care in general. In order to further increase the alliance's impact it is intended to extend the project's scope from regional to national coverage - nevertheless, such an endeavour can only be done in collaboration with the German Society for Hand Surgery (DGH). This article comprises 2 parts. First, the state-of-the-art of acute severe hand trauma care is summarised and explained. Subsequently, the above-mentioned pilot project is described in every detail, including positive effects but also barriers that still have to be overcome.

[Quality of life after brachial plexus lesions in adults]. / Lebensqualität bei posttraumatischen Paresen des Plexus brachialis im Erwachsenenalter.

Brachial plexus lesions are among the most severe injuries of the upper extremity. Despite intensive conservative and surgical treatment efforts, patients frequently suffer from serious impairments in the quality of life. This contribution presents the results of a retrospective clinical survey on the quality of life after brachial plexus injuries. Out of 38 treated patients, 25 patients could be included in the study. The disability of arm, shoulder and hand was evaluated by the DASH score and the quality of life by the FLZm, a questionnaire on life satisfaction. In addition, demographic data, work situation and mechanism and type of injury were recorded. The examined patients were mainly young males who were injured in traffic, in particular motorcycle accidents. The DASH score analysis revealed that plexus injuries are among the most disabling injuries of the upper extremity. The associated restrictions in the different sections of the quality of life involve not only the health-related section but also partnership, family and leisure time activities. A strong relation between the possibility to return to work and the quality of life was found. We recommend the use of the DASH score and the FLZm questionnaire on life satisfaction as routine tools for the evaluation of the therapeutic outcome after brachial plexus injuries.

[3-dimensional imaging systems: first experience in planning and documentation of plastic surgery procedures]. / 3-dimensionale Bilderfassung: Erste Erfahrungen in der Planung und Dokumentation plastisch-chirurgischer Operationen.

A reproducible 3-dimensional photographic system enables plastic surgeons to perform preoperative planning and helps them to understand the patient's expectations. There are a few systems available that allow a reproducible 3-dimensional scans of the patient with direct simulation of the planned procedure. The Vectra Volumetric 3D Surface Imaging® by Canfield® provides such an option and helps the surgeons to document and compare postoperative changes at different time points. Since January 2011 we are digitally documenting all patients receiving form-modulating procedures in our plastic surgery unit. We present the spectrum of clinical implications and discuss advantages and disadvantages of the system. Furthermore, we have studied the accuracy of the system in comparison to direct measurement in 15 volunteers. The system is especially suited for planning and evaluation of breast augmentation, facial aesthetic and reconstructive surgery as well as volumetric measurements before and after liposuction and lipofilling. Computer-assisted measurements correlate with a median deviation of 2.3% with manually measured distances in the face. We found the user-friendly Vectra® system to be a reliable and reproducible device for planning plastic surgery therapies and for documenting postoperative results.

[Microscope-integrated intraoperative indocyanine green angiography in plastic surgery]. / Intraoperative Indocyaningrün-Fluoreszenzdiagnostik mittels Operationsmikroskop in der plastischen Chirurgie.

The knowledge of tissue perfusion has not only a prognostic value in microvascular surgery but also the intraoperative detection of malperfusion can lead to a quick surgical intervention. Indocyanine green (ICG) angiography allows a topographic analysis of perfusion and is used to assess lymphatic drainage pathways and to analyse the depth of burn injuries. Integrating the technique into an operating microscope enables visualisation of the flow over microanastomoses and allows the assessment of the transit time of blood flow between arterial and venous anastomosis. Using this method we analysed 11 microsurgical free flaps (3 latissimus dorsi, 3 rectus abdominis, 1 gracilis muscle, 2 radial forearm, 1 ALT, and 1 DIEP flap). The topographic analysis was performed after the assessment of the microanastomoses. We observed no flap loss or partial flap necrosis. The transit time between arterial inflow and venous outflow was 32.8 s on average. Here we observed distinct differences between muscle flaps (27.7 s) on the one hand and fasciocutaneous and perforator flaps (47.5 s) on the other hand. We detected one venous thrombosis by ICG angiography in a case where the clinical patency test was not distinct. Revision was performed immediately. Particularly for intraoperative assessment, ICG angiography is a useful, reliable and safe technique. The integration into the operating microscope allows an "angiographic patency test" and the analysis of the transit time allows the evaluation of blood flow within the flap. Especially when planning perforator flaps the method of ICG angiography provides a new level of safety in flap design by quickly demonstrating the borders of perfusion.

[Treatment of Dupuytren's contracture by means of injectable collagenase: first clinical experiences]. / Die Behandlung der Dupuytrenschen Kontraktur mittels Kollagenase- Erste klinische Erfahrungen.

Recently a minimal invasive therapeutic option by means of enzymatic lysis of Dupuytren's cord was introduced in Europe under the name Xiapex® (Pfizer, Germany).Here we present our first experiences in clinical application with special remarks on complications.In this study 16 injections on 12 Dupuytren's cords in 8 patients were conducted. The average age of the patients was 62.5 (48-74) years. Constitution and application were carried out according to the manufacturer's guidelines. If both the metacarpophalangeal (MP)- and the proximal interphalangeal (PIP) joint were affected, injections were carried out on different points in time. 5 injections were done for contracture of the MPjoint, 4 injections for the PIPjoint, and 3 injections of both, the MP- and PIPjoint. Before the treatment and after 2 weeks the contracture of the treated joint was measured with use of a goniometer for small joints. Side effects and complications were documented as well as whether patients needed - and if yes, for how many days - a pain medication.Total flexion contracture of treated joints could be significantly reduced from 103°±12° to 37°±9°. In MPjoints the flexion contracture was reduced from 47°±8° to 14°±5° and in PIPjoints from 69°±10° to 37°±11° (p<0.05). 5 treated cords showed no signs of complication, recorded local adverse effects were edema (n=5), erythema (n=4) and tearing of skin (n=2). 6 patients needed pain medication for a maximum of 4 days.Treatment with collagenase appears to be an effective and safe therapeutic option for selective cases. Though the procedure ostensibly seems easy, one must emphasize the need for the appropriate application performed only by professionals with a high level of experience both in anatomical knowledge as well as hand surgical know-how to cope potential complications. The value of the new method in relation to the standard partial aponeurectomy and percutaneous needle fasciotomy needs to be ascertained by further research in order to establish a clear indication for each method of treatment.

[Phalloplasty with pedicled anterolateral thigh flap ("ALT-Flap")]. / Technik der Phalloplastik mittels gestielter anterolateraler Oberschenkel-Lappenplastik ("ALT-Flap").

Phalloplasty in female-to-male transsexuals is a very demanding procedure concerning preoperative planning and surgical implementation and many operative techniques have been described in the past. Here we illustrate the phalloplasty by means of a pedicled anterolateral-thigh-flap ("ALT-flap") in a patient who underwent unsuccessful groin-flap-phalloplasty alio loco. The sensible innervation was constituted via coaptation to a branch of the pudendal nerve. The technique presented here shows an aesthetically appealing result 6 months postoperatively with a 2-point discrimination of 2.5 cm and ongoing reinnervation. The operative time was reasonable with 360 min. The benefit of a pedicled transposition vs. a free transplantation becomes obvious especially as a salvage procedure in a preoperated situs with altered vascular anatomy. Additionally the shortened operating time and the lack of possible complications of microvascular anastomoses bear advantages. In conclusion we consider this technique for phalloplasty concerning operating time and effort, complications, donor site morbidity and aesthetic result as an appropriate alternative to established methods in selected patients.

[High pressure injection injuries of the hand. Rare but often underestimated]. / Hochdruckinjektionsverletzungen an der Hand. Selten, aber oft unterschätzt.

INTRODUCTION: Injection injuries of the hand are often underestimated because the full extent of the injury often only emerges after a delay. Flap coverage is often needed to avoid amputation. CASE REPORT: In the case presented an epoxy resin injection trauma to the left index finger occurred. A critical blood circulation resulted and after demarcation of the injury a radical débridement was carried out. A heterodigital island flap was used to reconstruct the dorsum of the finger and 3 years after the trauma the patient has no impairments in daily activities. DISCUSSION: The extent of the injury and the carcinogenic properties of the injected material are crucial for adequate treatment of injection injuries. Patients should be referred to specialized hand centers at an early stage.

Prediction of flap necrosis with laser induced indocyanine green fluorescence in a rat model.

Prediction of necrosis has a clinical relevance in all fields of plastic surgery. The new application of indocyanine green (ICG) fluoroscopy in plastic surgery allows an objective quantification of skin perfusion and a high topographical resolution. The aim of the present study is to determine threshold values for flap perfusion under well-defined experimental conditions. Twenty random pattern flaps with a length to width ratio of 4:1 (8 x 2 cm(2)) were dissected on the anterior abdominal wall of 20 male Sprague-Dawley rats. ICG fluoroscopy was performed at the end of the operation. The animals were sacrificed at the seventh postoperative day with a reliable necrosis of the distal part of the flaps. Postoperative ICG fluoroscopy then was analysed both in regions that will survive and undergo necrosis. At day 7 a mean area of 5.5 cm(2) (57% of the total flap area) survived and a mean of 3.8 cm(2) (43%) became necrotic. The surviving part of the flap had a mean perfusion index of 62% compared to reference skin. The distal parts of the flap that necrotised showed an average perfusion index of only 19% postoperatively. Differences were statistically highly significant (p<0.001). Indocyanine green fluoroscopy is a useful tool to evaluate perfusion topographically and predict necrosis. From a statistical point of view a perfusion index of less than 25% of the reference skin can be considered as a sign of developing flap necrosis.

[Angiogenesis VEGF165 gene therapy with AdVEGF- a new delay procedure for flaps]. / Angiogenese-Gentherapie mit AdVEGF.

A regular tissue functioning requires the adequate supply of oxygen and nutrient via blood vessels. The sequences of formation and maturation of vessels are initiated and maintained by different growth factors. The VEGF growth factor plays an exceptional role in these mechanisms. The creation of sublethal ischemia as an angiogenic stimulus known as "Delay" is a well established procedure in plastic surgery, although the underlying molecular biological mechanisms still remain unknown. The important role of VEGF and its regulation depending on oxygen pressure suggest a strong connection between this growth factor and the delay phenomenon. The VEGF concentration in skin and underlying muscle was measured in overdimensioned random pattern flaps on 32 male Sprague-Dawley rats after either VEGF gene therapy or circumcision without elevation of the flap and compared to controls. Additional random pattern flaps were raised seven days post gene therapy or delay. The effect on the flap perfusion was measured postoperatively using Indocyanine green Laser Fluoroscopy and the size of the surviving and necrotic areas of the flaps were analysed. The skin of the random pattern flaps showed both in the Delay group and in the VEGF gene therapy group a significantly elevated VEGF concentration compared to the controls. The underlying rectus abdominis muscle showed no significant differences in VEGF concentration between the groups. The flap perfusion postoperatively was significantly increased solely in the VEGF gene therapy group. The analysis of the surviving area of the flaps showed a significant increase over the controls in the gene therapy group. The Delay procedure results in a significantly and locally raised concentration of the VEGF growth factor. The gene therapeutical use of this growth factor allows us to raise flap perfusion and to reduce necrosis. Both VEGF gene therapy and Delay seem to promote similar mechanisms whereas the gene therapy produced superior results in this setting.

[Evaluation of perfusion in skin flaps by laser-induced indocyanine green fluorescence]. / Evaluation der Perfusion von Lappenplastiken mittels Laserfluoreszenz von Indocyaningrün.

Prediction of necrosis in critically perfused skin flaps is difficult and rarely precise. An early detection of insufficiently perfused skin is highly desirable since it may lead to surgical decisions such as operative flap revision or early resection. The application of laser-induced indocyanine green (ICG) fluoroscopy allows an objective quantification of skin perfusion and a high topographical resolution. Aim of the present study is to determine a threshold value for flap perfusion under well-defined experimental conditions and test the validity of the results in the clinical application. Twenty overdimensioned random pattern flaps with a length to width ratio of 4 : 1 (8 x 2 cm) were dissected at the anterior abdominal wall of 20 male Sprague-Dawley rats weighing 365 g on average. ICG fluorescence was performed at the end of the operation by intravenous injection of 1 g ICG/kg bodyweight into a tail vein and digital recording. On the seventh postoperative day, both the necrotic and surviving areas of the flaps were measured and the ICG-fluorescence was analysed in the areas that had undergone necrosis. 41 flaps with areas of critical perfusion (18 skin flaps, 13 muscle flaps, 8 replantations) were analysed in 39 patients. The surviving part of the flap had a mean perfusion index of 62 % compared to reference skin. The distal parts of the flap that necrotized during the experiment showed an average perfusion index of 19 % postoperatively. Differences were statistically significant (p < 0.001). In clinical application, a number of 13 flaps were found to have a perfusion index less than 25 % in a region of critical perfusion. Eleven of these developed a partial necrosis in that region, one flap underwent total necrosis. Indocyanine green fluoroscopy allows a detailed topographical analysis of flap perfusion and the prediction of necrosis. Experimental findings presented a threshold value for the perfusion index of 25 % which could be confirmed in clinical application.

AdVEGF165 gene transfer increases survival in overdimensioned skin flaps.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. VEGF A also plays an important role in wound healing of the skin by promoting angiogenesis and by stimulating blood vessel growth. Therefore we tested the hypothesis that flap survival could be increased by the preoperative injection of AdVEGF(165). METHODS: We studied the effect of AdVEGF(165) in an overdimensioned ischemic random-pattern-flap model in the rat (n = 50) with a length-to-width ratio of 4 : 1. VEGF cDNA was administered in two concentrations of 5 x 10(8) plaque-forming units (pfU) and 1 x 10(9) pfU using a recombinant adenoviral vector. Recombinant virus was injected subdermally 7, 3 or 0 days prior to flap harvest for the lower concentration and 7 days prior for the higher concentration. Flap survival and necrosis were observed at day 7, the day the animals were sacrificed. RESULTS: Adenoviral gene transfer with VEGF(165) 3 and 7 days before flap harvest showed a significantly increased flap survival of 50% together with a significantly reduced necrosis (p < 0.01). Injection using a titer of 1 x 10(9) pfU 7 days prior to surgery increased flap survival even more, though failing to reach statistical significance compared to the lower concentration. VEGF protein concentration in the injected skin was significantly higher than in controls (p < 0.01). Flap perfusion was increased as well, demonstrated by indocyanine green (ICG) fluoroscopy (p < 0.001). CONCLUSIONS: Our results confirm the important role of VEGF(165) on angiogenesis in ischemic flaps. Indeed by injecting VEGF(165) at 3 to 7 days preoperatively in a concentration of 1 x 10(9) pfU our data show that length-to-width ratio for random-pattern-flaps could be increased from 2 : 1 to 3 : 1 and therefore may allow a wider range of applications of this simple flap technique.