Mapping of Thoracodorsal Artery Perforators: Accuracy of Thermography and Handheld Doppler.

BACKGROUND: The versatile musculocutaneous latissimus dorsi flap and the thoracodorsal artery (TDA) perforator flap have developed into indispensable approaches in reconstructive surgery. While the anatomy of the TDA is consistent, the skin perforators vary in location and course. Dynamic infrared thermography (DIRT) recently gained popularity for perforator identification; however, its use and accuracy in thoracodorsal artery perforator (TDAP) mapping is yet to be determined. METHODS: TDAPs were visualized in 50 cases by DIRT. Based on the thermographic hotspots, the corresponding perforators were then identified by color duplex ultrasound (CDU) and handheld Doppler in a blinded fashion by two separate examiners. RESULTS: The midpoint of all perforator fascia passages was localized 99.7 mm caudal and 13.5 mm medial of the posterior axillary fold. The positive predictive value of perforator identification by dynamic infrared thermography was 86.5% and the correlating perforator fascia passage was 9.9 ± 5.8 mm from the hotspot midpoint, with a maximum of 29 mm. The positive predictive value of perforator identification by handheld Doppler was 95% and the signal was 7.2 ± 5.1 mm from the perforator fascia passage. CONCLUSION: DIRT precisely localizes TDAPs. The fusion with CDU combines both modalities' advantages. The combination with handheld Doppler is a fast way of perforator imaging, decreasing the handheld Dopplers' high false positive rate.

The effect of weather and temporal factors on emergency hand trauma consultations.

INTRODUCTION: Fluctuations in the numbers of patient consultations in hand trauma emergency units are challenging in terms of both scheduling and the provision of sufficient resources. Trauma consultations in general are affected by both temporal and meteorological variables. As the genesis and epidemiology of hand trauma have their own characteristics, this study aimed to identify the influence of temporal and meteorological factors on hand trauma consultations. MATERIALS AND METHODS: All patients treated for hand trauma in our level one trauma center in 2019 were included in the study population and the data were analyzed in retrospect. The daily weather data, including temperature, sunshine duration, precipitation, humidity and wind speed, as well as temporal factors such as time of day, weekday and public holidays were considered and correlated with patient consultations. Gender differences were studied as well. RESULTS: We included 4787 hand trauma patients (66.4% male, mean age 38.4 ± 19.3 years, 31.7% occupational injuries). Significantly more consultations occurred on Saturdays as compared to weekdays (14.8 ± 0.6, n = 52 vs. 13.0 ± 0.2, n = 261; p = 0.028), and fewer occurred on official holidays (11.8 ± 0.5, n = 63 vs. 13.4 ± 0.2, n = 302; p = 0.0047). We found a significant positive correlation between daily consultations, sunshine duration (r = 0.14, p = 0.0056) and the mean temperature (r = 0.20, p < 0.0001); in contrast, a significant negative correlation between daily consultations and humidity (r = - 0.17, p = 0.001) was observed. Furthermore, fewer consultations were seen on days with precipitation (12.7 ± 0.3, n = 219 vs. 13.8 ± 0.3, n = 146; p = 0.009). The variation was considerably stronger in men. CONCLUSIONS: Hand trauma consultations increased with increasing temperatures, duration of sunshine, and decreasing humidity. Peak admissions were seen on Fridays and Saturdays. These findings can assist in predicting days with peak admissions to allocate resources appropriately.

The corticocancellous press fit iliac crest bone dowel for recalcitrant scaphoid nonunion: analysis of union rate and clinical outcome.

INTRODUCTION: Scaphoid nonunion after failed primary treatment remains challenging particularly when entailed by bone loss, avascular necrosis or deformity. We describe a scaphoid augmentation and fixation technique for cases of recalcitrant nonunion after screw placement by autologous press fit corticocancellous dowel. This study aims to provide reliable data on clinical and radiological outcomes and to contextualize in the face of other treatment options. MATERIAL AND METHODS: The study included 16 patients with recalcitrant nonunion of the scaphoid. All patients received screw removal and scaphoid reconstruction by a dowel shaped non-vascularized corticocancellous bone graft from the iliac crest facilitating packing of the screw channel. Bone union, the scapholunate, radiolunate and intrascaphoidal angles were evaluated on X-ray and CT images, range of motion noted. Additionally grip strength, DASH and Green O'Brien scores were obtained from eight patients. RESULTS: A union rate of 73% was noted after mean follow-up of 54 months. After revisional reconstruction of the scaphoid an extension-flexion rate of 84% of the healthy side was noted while pronation-supination reached 101%. DASH score averaged at 2.9, rest pain on a numeric rating scale was 0.43 with 99% peak grip force of the healthy side. CONCLUSION: In complex cases of revisional scaphoid nonunion after screw placement, the corticocancellous iliac crest pressfit dowel is an option for augmentation and stabilization of the scaphoid by preserving the articular surface. LEVEL OF EVIDENCE: IV, retrospective case series.

Precision of Dynamic Infrared Thermography in Anterolateral Thigh Flap Planning: Identification of the Perforator Fascia Passage.

BACKGROUND: The anterolateral thigh (ALT) flap is commonly utilized in reconstructive surgery. Preoperative perforator mapping facilitates dissection. Dynamic infrared thermography can be applied to identify ALT perforators. However, its accuracy has not been evaluated in detail before. Therefore, this study aimed to assess the precision of dynamic infrared thermography in ALT perforator localization. METHODS: The survey site was defined as a 25 × 8 cm rectangle on the anterolateral thigh and a coordinate system was established. The area was examined consecutively by dynamic infrared thermography with a FLIR ONE camera after 2-minute fan precooling. Two surgeons then independently performed color duplex ultrasound on the basis of the identified hotpots. RESULTS: Twenty-four healthy subjects were examined. About 74.8% of perforators were musculocutaneous or musculoseptocutaneous. The mean distance between study area center and perforator or hotspot center was 51.8 ± 27.3 and 46.5 ± 26.2 mm, respectively. The mean distance from hotspot center to sonographic perforator fascia passage was 15.9 ± 9.9 mm with a maximum of 48.4 mm. The positive predictive value of thermographic ALT perforator identification was 93%. CONCLUSION: Thermographic hotspot and perforator location diverge widely in ALT flaps. Dynamic infrared thermography can therefore not be used as standalone technique for preoperative ALT perforator identification. However, the application before color duplex ultrasound examination is a reasonable upgrade and can visualize angiosomes and facilitate the examination.

Thermography Supported Color Duplex Ultrasound Accelerates ALT Perforator Imaging.

BACKGROUND: The anterolateral thigh flap is a versatile and dependable perforator flap and is a popular choice in the reconstruction of various body sites. The variable perforator anatomy suggests preoperative perforator imaging to improve safety and speed of dissection. An innovative perforator imaging technique is thermography, which lately gained attention in plastic surgery. METHODS: Thirty-two healthy participants were included in this randomized study. One thigh was examined with dynamic infrared thermography and consecutively with ultrasound, while the contralateral thigh was examined with ultrasound as standalone technology. RESULTS: The application of dynamic infrared thermography prior to ultrasound perforator identification significantly accelerated the ultrasound examination duration by 90 to 130 seconds. The mean duplex ultrasound examination duration correlated positively with the hotspot and perforator quantity per thigh. CONCLUSION: The addition of thermographic perforator mapping can accelerate color duplex ultrasound anterolateral thigh perforator imaging. Furthermore, thermography supplements color duplex ultrasound with crucial information on angiosome location.

Does leg dominance influence anterolateral thigh flap perforators?

INTRODUCTION: Thorough knowledge of perforator anatomy can facilitate anterolateral thigh (ALT) free flap harvest. The selection of the right or left thigh as donor area may be supported by preoperative perforator imaging and practical considerations. The study aims to determine if the leg dominance should be taken into account, when choosing the donor thigh for ALT free flap harvest, as muscle mass and perfusion might influence perforator quantity. METHODS: ALT perforators were localized by color-coded duplex sonography and dynamic infrared thermography on both thighs within a defined 250 × 80 mm area in 24 subjects. Perforator number and thickness of subcutaneous tissue and muscle layer were compared in dominant and nondominant legs. RESULTS: We found no statistically significant difference comparing sonographically identified ALT perforator numbers and hot spot numbers in dominant and nondominant legs. Yet, we found high interindividual differences. The comparison of subcutaneous tissue and muscle thickness yielded no significant difference. CONCLUSIONS: Our study yielded no evidence for preference of the dominant or nondominant leg in ALT free flap harvesting. As we found high interindividual differences in perforator number, we suggest to rely on preoperative perforator imaging when choosing the ALT free flap donor thigh.

Air Flow Cooling Improves Anterolateral Thigh Perforator Mapping Using the FLIR ONE Thermal Camera.

BACKGROUND: Due to the variable vascular anatomy preoperative perforator mapping facilitates anterolateral thigh (ALT) free flap harvesting. Dynamic infrared perforator imaging can assist preoperative planning by displaying hot spots that represent angiosomes. This study aims to compare previously described precooling methods to develop a standardized simplified protocol for ALT perforator planning. METHODS: Fifty thighs were examined with a FLIR ONE thermal camera. Four different cold challenges, including alcoholic disinfection, wet laparotomy sponge cooling, fan cooling, and cold pack application, were compared. Hot spot locations within a 250 mm × 80 mm area were compared double-blinded to perforator locations determined by Doppler ultrasonography considered as gold standard. RESULTS: The matching rate of thermographic hot spots and sonographically identified perforators was 34.9 ± 22.2%. An increased matching rate of 62.2 ± 42.2% was noted taking only favored perforators (septocutaneous course, diameter >1 mm, distance <3 cm to the center, and visible concomitant veins) into account. Precooling with a fan followed by alcoholic disinfection provided clearest thermograms and fastest results. CONCLUSION: Thermographic imaging is a reliable method for perforator imaging. Its supplemental use to ultrasound may reduce examination time and yield additional information. Precooling by air flow or alcoholic disinfection can be easily implemented and provide the best thermograms. The matching rate of thermographic hot spots and perforators increases when taking only clinically relevant perforators into account. Thermal perforator mapping therefore reduces distraction by negligible perforators.

A Training Model for Local Flaps Using Fresh Human Skin Excised During Body Contouring Procedures.

BACKGROUND: The safe execution of local flaps tends to be challenging for surgical residents. Thus, the purpose of the study was to evaluate a training model of local flaps based on fresh human skin excised from body contouring procedures. MATERIALS AND METHODS: A questionnaire and surgical skills evaluation-analyzing the theoretical and procedural knowledge about local flaps-were held both before and after the surgical skills training. All surgical procedures were executed on a simulation model based on fresh human skin. Skills evaluation was done according to a modified version of the Objective Structured Assessment of Technical Skills Score. Results before and after the training were compared using SPSS, version 21. RESULTS: In pretraining evaluation, residents showed great difficulty regarding the accuracy of flap design and sufficiency of wound coverage indicating the need for surgical training outside the operating theater. After training, the procedural skills significantly improved as depicted by the modified Objective Structured Assessment of Technical Skills score with a mean cumulative pretraining score of 26.81 ± 5.41 and posttraining score of 43.59 ± 5.72 (P = 0.008). Also, theoretical knowledge significantly improved in the posttraining evaluation with exception to the indication of a Z-plasty (P = 0.257). The training model itself was generally regarded as highly useful and thus recommendable to others. CONCLUSIONS: Surgical handling and the understanding of tissue rotation clearly improved by the presented model which mimics very realistic conditions. The simulation model based on fresh human skin shows cost-effectiveness and allows a broad range for flap procedures wherefore its use should be further promoted.

Transplantation of a latissimus dorsi flap after nearly 6 hr of extracorporal perfusion: A case report.

Prolonged ischemia of tissues inevitably leads to their necrosis. This is especially relevant in the case of transplantation or replantation. In such situations, reperfusion in a timely manner might not be possible due to transportation times or other unforeseen complications. Therefore, a readily available and simple method to oxygenate the tissue and thus widen the time frame to reperfusion seems desirable. Here, we present the case of extracorporal perfusion of a latissimus dorsi (LD) flap that was successfully transplanted after nearly 6 hr of ischemia. A 41-year-old patient suffered multiple injuries including complete severance of the popliteal artery requiring emergency bypass. After stabilization of the patient and subsequent debridement, a LD flap was performed for soft tissue coverage. However, there was an acute occlusion of the bypass during flap inset. To salvage the free flap, a one-way extracorporal perfusion of the flap with heparinized isotonic saline solution was performed for a total of 5 hr and 47 min. The flap survived with minimal tip necrosis. This case report describes the application of a simple extracorporal perfusion technique for salvage of a free flap over a prolonged ischemia time and discusses the relevant literature. Due to its ease and quickness of application as well as ubiquitous availability, it might serve as a valuable tool in cases of acute problems with the recipient vessels or other incidents where several hours of ischemia time are to be anticipated.

C-terminal truncations in human 3'-5' DNA exonuclease TREX1 cause autosomal dominant retinal vasculopathy with cerebral leukodystrophy.

Autosomal dominant retinal vasculopathy with cerebral leukodystrophy is a microvascular endotheliopathy with middle-age onset. In nine families, we identified heterozygous C-terminal frameshift mutations in TREX1, which encodes a 3'-5' exonuclease. These truncated proteins retain exonuclease activity but lose normal perinuclear localization. These data have implications for the maintenance of vascular integrity in the degenerative cerebral microangiopathies leading to stroke and dementias.

Advances in Modern Microsurgery.

Background/Objectives: Microsurgery employs techniques requiring optical magnification and specialized instruments to operate on small anatomical structures, including small vessels. These methods are integral to plastic surgery, enabling procedures such as free tissue transfer, nerve reconstruction, replantation, and lymphatic surgery. This paper explores the historical development, advancements, and current applications of microsurgery in plastic surgery. Methods: The databases MEDLINE (via PubMed) and Web of Science were selectively searched with the term "(((microsurgery) OR (advances)) OR (robotic)) OR (AI)) AND (((lymphatic surgery) OR (peripheral nerve surgery)) OR (allotransplantation))" and manually checked for relevance. Additionally, a supplementary search among the references of all publications included was performed. Articles were included that were published in English or German up to June 2024. Results: Modern microsurgical techniques have revolutionized plastic surgery, enabling precise tissue transfers, improved nerve reconstruction, and effective lymphedema treatments. The evolution of robotic-assisted surgery, with systems like da Vinci and MUSA, has enhanced precision and reduced operative times. Innovations in imaging, such as magnetic resonance (MR) lymphography and near-infrared fluorescence, have significantly improved surgical planning and outcomes. Conclusions: The continuous advancements in microsurgery, including supermicrosurgical techniques and robotic assistance, have significantly enhanced the capabilities and outcomes of plastic surgery. Future developments in AI and robotics promise further improvements in precision and efficiency, while new imaging modalities and surgical techniques expand the scope and success of microsurgical interventions.

Extending the Indications for Direct Transcutaneous Lower Blepharoplasty With an Infraorbital Incision to Tear Trough Deformities, Suborbicularis Oculi Fat, Festoons, and Revision Blepharoplasty.

Introduction: Treatment of high-grade lower eyelid deformities with massive skin laxity and retroseptal fat pads can be challenging. Common techniques such as the transconjunctival approach and transcutaneous technique performed through a subciliary incision are associated with increased complication rates. Direct excision of the lower eyelid through an infraorbital incision is an alternative technique that allows safe treatment of dermatochalasis and pigmentation and correction of tear trough deformities, suborbicularis oculi fat, and festoons. This study aimed to determine whether direct transcutaneous blepharoplasty with an infraorbital incision could be indicated for these conditions instead of the established operative methods. Methods: A retrospective study of 21 patients with Fratila grades 9 or 10, Hirmand grade 3, and Barton grade 3 who underwent direct transcutaneous lower eyelid blepharoplasty via an infraorbital incision under local anesthesia was performed. All patients underwent surgery during a 9-year period from January 2010 to December 2018. The follow-up period was 12 months. Results were rated postoperatively using Barton grading. Results: Of 21 consecutive patients (13 women and 8 men), 18 required retroseptal fat pad removal, 3 had laxity of the skin and orbicularis muscle, and 5 had triangular cheek festoons. Combined lower and upper blepharoplasty was performed for 12 patients. All patients were satisfied with their surgical results and major improvements were observed. Scar quality was considered good by all patients. Conclusion: Direct transcutaneous lower blepharoplasty of the orbital rim can be indicated for different tear trough deformities, suborbicularis oculi fat laxity, and festoons.

Introduction: Le traitement des difformités de haut grade de la paupière inférieure avec laxité cutanée majeure et amas de graisse rétroseptale peut être un défi. Les techniques habituelles, comme l'approche transconjonctivale et la technique transcutanée, exécutées au travers d'une incision infraciliare sont associées à des taux de complications plus importants. L'excision directe de la paupière inférieure par une incision sous-orbitaire est une autre technique qui permet un traitement sécuritaire du dermatochalasis, de la pigmentation et de la correction des cernes sombres, le tissu adipeux sous-orbitaire et les poches oculaires. Cette étude visait à déterminer si une blépharoplastie directe transcutanée avec incision sous-orbitaire pouvait recevoir une indication pour ces problèmes à la place des techniques opératoires usuelles. Méthodes: Une étude rétrospective a été menée, incluant 21 patients ayant des grades Fratila 9 ou 10, Hirmand 3 et Barton 3; les patients ont subi sous anesthésie locale une blépharoplastie transcutanée de la paupière inférieure par incision sous-orbitaire. Les interventions ont eu lieu dans une période de 9 ans, de janvier 2010 à décembre 2018. La phase de suivi a été de 12 mois. Les résultats ont été évalués en post opératoire selon l'échelle de Barton. Résultats: Parmi 21 patients consécutifs (13 femmes et 8 hommes), 18 ont nécessité la suppression d'un amas de graisse rétroseptale, 3 avaient une laxité de la peau et du muscle orbiculaire et 5 avaient des poches triangulaires sur les joues. Une blépharoplastie combinée supérieure et inférieure a été pratiquée chez 12 patients. Tous les patients ont été satisfaits par les résultats de la chirurgie et des améliorations majeures ont été constatées. Tous les patients ont considéré que la qualité de la cicatrice était bonne. Conclusion: Une blépharoplastie inférieure transcutanée directe du pourtour orbitaire peut être indiquée pour différentes formes de dépression sombre formant des cernes foncés, la laxité de la graisse oculaire sous-orbitaire et les poches sous les yeux.

Outpatient care for facial palsy-a survey on patient satisfaction in uni- and interdisciplinary approaches.

Objective: The various causes of facial palsy, diagnostic methods and treatment approaches frequently involve different medical specialities. Nevertheless, there exist only few specialized consultation and therapy services for patients with facial palsy (FP) in Germany. The aim of the present study was to evaluate factors affecting quality of life (QoL) and treatment satisfaction of patients presenting to an interdisciplinary facial nerve outpatient clinic. Methods: The study analyzed patients presenting to the interdisciplinary facial palsy outpatient clinic in Tuebingen between February 2019 and December 2022. General satisfaction and QoL was estimated by numerous self-rating questionnaires: ZUF-8, SF-36, FDI, FaCE, PHQ-9. An ANOVA was performed to analyze determinants affecting the ZUF-8. Correlation analyses between cause and regeneration of FP as well as questionnaire scores were performed. Results were compared with a group of patients who were managed in an unidisciplinary setting. Results: In total, 66 patients with FP were enrolled. FP patients showed increased levels of depression (PHQ-9: 14.52 ± 3.8) correlating with recovery of the palsy (p = 0.008), FaCE (p < 0.001) and FDI ratings (p < 0.001). There was a high level of satisfaction with the services provided during the uni-and interdisciplinary consultation (ZUF-8: 24.59 ± 6.2), especially among the 12/66 patients who received reconstructive, surgical treatment. However, some patients requested more psychological and ophthalmological support. Conclusion: High levels of treatment satisfaction can be achieved in both an uni-and interdisciplinary setting. However, multimodal therapy approaches should be applied, considering physical and psychological aspects. In the absence of recovery, surgical interventions must be considered as treatment options. Further studies should continue to investigate potential differences between uni-and interdisciplinary treatment.

Quantification of Dermal Microcirculatory Changes after Topical Administration of Capsaicin: A Randomized Placebo-Controlled Study in 46 Subjects.

BACKGROUND: Dermal blood flow is crucial for wound healing and survival of flaps in dermatologic surgery. To improve flap viability in cases of compromised perfusion topical agents can easily be applied. The aim of this placebo-controlled study was to characterize changes of DBF in healthy subjects by quantitatively assessing perfusion dynamics after application of capsaicin to establish a reference for measurements at injured sites. METHODS: In 46 healthy subjects perfusion dynamics after local application with capsaicin and placebo was noninvasively assessed, determining cutaneous oxygen saturation, relative hemoglobin count and blood flow using an Oxygen-to-See device. RESULTS: A significant raise in superficial (162% p = 0.000) and deep (144%, p = 0.000) skin oxygenation after 30 min was provoked. A highly significant raise in measurements of flow and velocity was present in superficial (523%, p = 0.000) and deep (242%, p = 0.000) sites. CONCLUSION: With the introduced model applied to observe changes in parameters of dermal blood flow in healthy subjects the authors can reliably monitor effects of topically administered capsaicin. This baseline can be used as reference for further studies in the settings of endangered flap survival or critically perfused wounds as has been proven in animal studies.

Design and Evaluation of a Custom-Made Electromyographic Biofeedback System for Facial Rehabilitation.

Background: In the rehabilitation of postoperative facial palsy, physical therapy is of paramount importance. However, in the early rehabilitation phase, voluntary movements are often limited, and thus, the motivation of patients is impacted. In these situations, biofeedback of facial electromyographic (EMG) signals enables the visual representation of the rehabilitation progress, even without apparent facial movements. In the present study, we designed and evaluated a custom-made EMG biofeedback system enabling cost-effective facial rehabilitation. Methods: This prospective study describes a custom-made EMG system, consisting of a microcontroller board and muscle sensors, which was used to record the EMG of frontal and zygomatic facial muscles during frowning and smiling. First, the mean EMG amplitudes and movement onset detection rates (ACC) achieved with the custom-made EMG system were compared with a commercial EMG device in 12 healthy subjects. Subsequently, the custom-made device was applied to 12 patients with and without postoperative facial paresis after neurosurgical intervention. Here, the ratio [laterality index (LI)] between the mean EMG amplitude of the healthy and affected side was calculated and related to the facial function as measured by the House and Brackmann scale (H&B) ranging from 1 (normal) to 6 (total paralysis). Results: In healthy subjects, a good correlation was measured between the mean EMG amplitudes of the custom-made and commercial EMG device for both frontal (r = 0.84, p = 0.001) and zygomatic muscles (r = 0.8, p = 0.002). In patients, the LI of the frontal and zygomatic muscles correlated significantly with the H&B (r = -0.83, p = 0.001 and r = -0.65, p = 0.023). The ACC of the custom-made EMG system varied between 65 and 79% depending on the recorded muscle and cohort. Conclusion: The present study demonstrates a good application potential of our custom-made EMG biofeedback device to detect facial EMG activity in healthy subjects as well as patients with facial palsies. There is a correlation between the electrophysiological measurements and the clinical outcome. Such a device might enable cost-efficient home-based facial EMG biofeedback. However, movement detection accuracy should be improved in future studies to reach ranges of commercial devices.

[Acute calcific periarthritis - a differential diagnosis of pyoarthrosis of the hand]. / Die akute kalzifizierende Periarthritis als Differentialdiagnose des Gelenkempyems an der Hand.

BACKGROUND: The acute calcific periarthritis is caused by hydroxyapatite deposits in the periarticular soft tissue.The symptoms resemble a pyoarthrosis, explaining high rates of misdiagnosis. PATIENTS: Presented are the cases of a 45 and a 46 years old patient, who presented with acute onset of swelling, erythema, functional impairment and pain of the hand. Periarticular calcifications were identified radiologically. RESULTS: The symptoms completely resolved in both patients within few days under conservative treatment. CONCLUSION: The acute calcific periarthritis should be considered as a differential diagnosis of pyoarthrosis in the hand, especially if no suitable trauma preceeded. Usually conservative treatment with immobilization and antiphlogistic drugs rapidly leads to a complete remission.

[Microsurgery Training with a Commercial Smartphone Kit - a new Device]. / Neues, Smartphone-gestütztes mikrochirurgisches Trainingsmodell.

Microsurgical dissection and suturing techniques require persistent practice and perseverance. Rookies in particular often practice on the "dry model" in order to achieve a smooth transition to the application on the patient in the surgical theatre. Whether surgical glove, pig heart, with magnifying glasses, as a virtual reality tool, rat model with or without a training microscope - many different exercise models are described. For a number of years, self-made devices with smartphone cameras as a magnifying aid have also been known and are sometimes used. There is now a new commercial system from the US which allows the trainee to learn basic microsurgical techniques at any time and almost anywhere, or to perfect advanced knotting techniques such as the "through-the-loop" knot relatively easily and inexpensively. For this purpose, a conventional smartphone can be clamped in a 3 D swivel arm and anastomoses can be practiced on various vessel lumens. The smartphone therefor mimics a surgical microscope. There are prefabricated "cards" with built-in small plastic tubes of various diameters (1-3 mm) that can be used for practice.We believe that in the future such training kits can be part of the standard reporting in microsurgical training for interns and students in microsurgical centers.

Differential regulation of chondroitin sulfate proteoglycan mRNAs in the denervated rat fascia dentata after unilateral entorhinal cortex lesion.

Following brain trauma, chondroitin sulphate proteoglycans (CSPGs) are enriched at injury sites and in denervated areas. At injury sites, CSPGs are regarded as inhibitors of axonal regeneration because of their growth inhibitory properties. In areas of denervation their role is less clear, since they are enriched in zones of sprouting, i.e. zones of axonal growth. To identify CSPGs expressed in a denervated brain area and to quantify changes in their mRNA expression, neurocan, brevican, NG2, phosphacan and aggrecan mRNA were analyzed in the rat fascia dentata following entorhinal denervation. Laser microdissection was combined with quantitative RT-PCR to measure mRNA changes specifically within the denervated portion of the molecular layer (1h, 6h, 10h, 12h, 1d, 2d, 3d, 4d, 7d and 14d post-lesion). Changes in glial fibrillary protein mRNA were measured at the same time points and used as lesion control. This approach revealed a differential regulation of CSPG mRNAs in the denervated zone: neurocan, brevican and NG2 mRNA were upregulated with a maximum around 2 days post-lesion. In contrast, aggrecan mRNA levels reached a maximum 7 days post-lesion and phosphacan mRNA levels were not significantly altered. Taken together, our data reveal a temporal pattern in CSPG mRNA expression in the denervated fascia dentata. This suggests specific biological functions for CSPGs during the denervation-induced reorganization process: whereas the early increase in CSPGs in the denervated zone could influence the pattern of sprouting, the late increase of aggrecan mRNA suggests a different role during the late phase of reorganization.

NG2 upregulation in the denervated rat fascia dentata following unilateral entorhinal cortex lesion.

The chondroitin sulfate proteoglycan NG2 is a component of the glial scar following brain injury. Because of its growth inhibiting properties, it has been suggested to impede axonal regeneration. To study whether NG2 could also regulate axonal growth in denervated brain areas, changes in NG2 were studied in the rat fascia dentata following entorhinal deafferentation and were correlated with the post-lesional sprouting response. Laser microdissection was employed to selectively harvest the denervated molecular layer and combined with quantitative RT-PCR to measure changes in NG2 mRNA (6 h, 12 h, 2 days, 4 days, 7 days post-lesion). This revealed increases of NG2 mRNA at day 2 (2.5-fold) and day 4 (2-fold) post-lesion. Immunocytochemistry was used to detect changes in NG2 protein (1 days, 4 days, 7 days, 10 days, 14 days, 30 days, 6 months post-lesion). NG2 staining was increased in the denervated outer molecular layer at day 1 post-lesion, reached a maximum 10 days post-lesion, and returned to control levels thereafter. Electron microscopy revealed NG2 immunoprecipitate on glial surfaces and in the extracellular matrix around neuronal profiles, indicating that NG2 is secreted following denervation. Double labeling of NG2-immunopositive cells with markers for astrocytes, microglia/macrophages, and mature oligodendrocytes suggested that NG2 cells are a distinct glial subpopulation before and after entorhinal deafferentation. BrdU labeling revealed that some of the NG2-positive cells are generated post-lesion. Taken together, our data revealed a layer-specific upregulation of NG2 in the denervated fascia dentata that coincides with the sprouting response. This suggests that NG2 could regulate lesion-induced axonal growth in denervated areas of the brain.