Microvascular Anastomosis Research Articles

The Use of Pedicular Arteriovenous Fistula (PAVF) in Microvascular Reconstruction to Enhance Flow Across the Microvascular Anastomoses.

Free flap success rates have improved dramatically over the past three decades, setting a high standard for microvascular reconstruction. However, rates of arterial or venous thrombosis, and subsequent failure, remain high in burn and trauma reconstruction when compared to autologous breast reconstruction and other elective flaps. To address the higher failure rate, we use a novel vascular approach. We create a pedicular arteriovenous fistula (PAVF), allowing the flow to be enhanced across the microvascular anastomoses. We performed a retrospective review of 13 consecutive patients with 14 free flaps who underwent PAVF creation by the first author, AO. All patients who required free tissue transfer for trauma and burn reconstruction were indicated for PAVF during this study period. The flaps in this study included ALT, fibula, parascapular, and partial latissimus. The perforator and pedicle for the flaps were dissected in the usual manner. Distal to the takeoff of the perforator to the flap, the pedicular artery and the larger of the accompanying veins were anastomosed to create the PAVF. Patients were followed for a mean of 171 days Thrombosis was a rare complication in the group with one venous thrombosis (n = 1, 7.14%) and no arterial thrombosis. The most common complication was return to the operating room n = 4 (28.57%), two of which secondary to hematomas (14.29%), one wound dehiscence and one venous thrombosis. This latter patient eventually had partial flap loss. We did not observe flap ischemia due to vascular steal, nor any venous congestion from pressurizing the venous outflow. As opposed to anticoagulation, flow enhancement aims to decrease the risk of thrombosis by reducing stasis. While further data is needed to compare the outcomes of venous enhanced flaps when compared to flaps treated prophylactically with anticoagulation, our initial data suggests that PAVF is a safe procedure and does not result in vascular steal or flap congestion.

Is the Sublingual Artery a Reliable Alternative for Intraoral Anastomoses in Head and Neck Free-Flap Reconstruction? Anatomical Basis and Preliminary Results

Background/Objectives: Head and neck free-flap reconstructions are often required to treat tumors or extensive post-traumatic jaw defects. The facial artery is the standard receiving vessel for intraoral microvascular anastomoses. However, its use is associated with several disadvantages, such as lesions of buccal nerve branches of the facial nerve or the parotid duct, as well as variability in course and diameter. The aim of this study is to investigate whether branches of the sublingual artery can be considered as an alternative intraoral supply vessel to the facial artery to avoid these drawbacks. Methods: Twelve formalin-fixed cadaveric heads with 24 sides (n = 24) were dissected. The origin, course, branching pattern, and distribution of the sublingual artery were examined. In addition, the diameters of the branches of the sublingual artery were assessed to identify potential supply vessels for anastomoses. Results: In ten of the twenty-four cases (41.7%), the sublingual artery originated from the lingual artery, and in nine cases (37.5%), the lingual artery originated from the facial artery. The main trunk of the sublingual artery was present in the floor of the mouth in all cases (100%), with a diameter of ≥0.9 mm in vitro (1 mm in vivo). In 15 of the 24 half heads (62.5%), branches of the sublingual artery with ≥0.9 mm were identified in this space, with the main branch being considerably stronger. Conclusions: The large diameter of the sublingual artery in the floor of the mandible suggests that this vessel or its branches could be considered as alternative pedicles for intraoral anastomoses in mandibular microvascular free-flap grafts.

Mechanical Viability and Functionality Assessment of a New Sutureless Endoluminal Microvascular Device: A Preliminary In Vivo Rabbit Study.

Our group has developed a new nitinol endoluminal self-expandable device for microvascular anastomosis. It attaches to each vessel ending with opposite directed microspikes and reaches complete expansion at body temperature, using the nitinol shape memory capacity. The main purpose of this first in vivo trial is to evaluate the mechanical viability of the device and its immediate and early functionality. A recuperation study with seven New Zealand White rabbits was designed. A 1.96 mm outer diameter prototype of the new device was placed on the right femoral artery of each rabbit. Each anastomosis was reassessed on the seventh postoperative day to reevaluate the device function. The average anastomosis time with the new device was 18 min and 45 seg (±0.3 seg). It could be easily placed in all the cases with an average of 1.14 (1) complementary stitches needed to achieve a sealed anastomosis. Patency test was positive for all the cases on the immediate assessment. On the 1 week revision surgery, patency test was negative for the seven rabbits due to blood clot formation inside the device. The new device that we have developed is simple to use and shows correct immediate functionality. On the early assessment, the presence of a foreign body in the endoluminal space caused blood clot formation. We speculate that a heparin eluting version of the device could avoid thrombosis formation. We consider that the results obtained can be valuable for other endoluminal sutureless devices.

Neurosurgical Microvascular Anastomosis: Systematic Review of the Existing Simulators and Proposal of a New Training Classification System.

The literature lacks a combined analysis of neurosurgical microvascular anastomosis training models. We performed a systematic literature search to provide an overview of the existing models and proposed a classification system based on the level of simulation and reproducibility of the microvascular anastomosis. The systematic literature search followed the PRISMA guidelines. We consulted MEDLINE, Web of Knowledge, and EMBASE independently for papers about bypass training models. Every training model was analyzed according to six tasks supposed to esteem their fidelity to the real operative setting by using a scoring system from zero to two. Finally, authors classified the models into five classes, from A to E, by summing the individual scores. This study included 109 papers for analysis. Training models were grouped into synthetic tubes, ex vivo models (animal vessels, fresh human cadavers, human placentas) and in vivo simulators (live animals-rats, rabbits, pigs). By applying the proposed classification system, live animals and placentas obtained the highest scores, falling into class A (excellent simulators). Human cadavers and animal vessels (ex vivo) were categorized in class B (good simulators), followed by synthetic tubes (class C, reasonable simulators). The proposed classification system helps the neurosurgeon to analyze the available training models for microvascular anastomosis critically, and to choose the most appropriate one according to the skills they need to improve.

Microsurgical Reconstruction with and without Microvascular Anastomosis of Oncological Defects of the Upper Limb.

The choice of the most adequate surgical technique for upper limb defects remains challenging. The aim of this article is to discuss the main microsurgical (pedicled or free) reconstructive options for the post-oncological reconstruction of different anatomical areas of the upper extremity. We reviewed different reconstructive methods reported in the literature needing microsurgical expertise and compared them to our clinical experience, in order to provide further guidance in the choice of different flaps for upper limb soft tissue reconstruction. Six clinical cases, one for each anatomical district, are presented as examples of possible solutions. We report the options available in the literature for post-oncologic upper limb reconstruction, dividing them by anatomical area and type of flap: local flaps, regional flaps, free flaps, and distant pedicled flaps. Our examples of the reconstruction of each anatomical area of the upper limb include one reverse ulnar pedicled perforator flap, one free Antero-Lateral Thigh (ALT) flow-through flap, one perforator-based lateral arm flap, two myocutaneous latissimus dorsi pedicled flaps, and one parascapular perforator-plus flap. In oncological cases, it is important to consider reconstructive options that provide stable tissue and allow for the early healing of the donor and recipient site if the patient needs to undergo adjuvant radiotherapy or chemotherapy. A wider range of flap options is essential when choosing the proper technique according to the patient's needs, surgeon's preference, and logistical possibilities. Perforator flaps combine the advantages of other flaps, but they require microsurgical expertise. Free flap reconstruction remains the gold standard to obtain a better overall and cosmetic outcome in complex and wide defects, where no suitable local pedicled flap option exists. The pedicled latissimus dorsi flap should still be included among the reconstructive options for its strong vascularization, size, and arc of transposition.

Gastric conduit reconstruction after esophagectomy.

A high risk of complications still accompanies gastric conduit reconstruction after esophagectomy. In this narrative review, we summarize the technological progress and the problems of gastric conduit reconstruction after esophagectomy. Several types of gastric conduits exist, including the whole stomach and the narrow gastric tube. The clinical outcomes are similar between the two types of conduits. Sufficient blood supply to the conduit is mandatory for a successful esophageal reconstruction. Recently, due to the availability of equipment and its convenience, indocyanine green angiography has been rapidly spreading. When the blood perfusion of the planning anastomotic site is insufficient, several techniques, such as the Kocher maneuver, pedunculated gastric tube with duodenal transection, and additional microvascular anastomosis, exist to decrease the risk of anastomotic failure. There are two different anastomotic sites, cervical and thoracic, and mainly two reconstructive routes, retrosternal and posterior mediastinal routes. Meta-analyses showed no significant difference in outcomes between the anastomotic sites as well as the reconstructive routes. Anastomotic techniques include hand-sewn, circular, and linear stapling. Anastomoses using linear stapling is advantageous in decreasing anastomosis-related complications. Arteriosclerosis and poorly controlled diabetes are the risk factors for anastomotic leakage, while a narrow upper mediastinal space and a damaged stomach predict leakage. Although standardization among the institutional team members is essential to decrease anastomotic complications, surgeons should learn several technical options for predictable or unpredictable intraoperative situations.

Treatment of distal femur aseptic nonunion after lateral locking plate fixation: results of medial custom made plating and free fibula flap transfer using CAD-CAM technology

BackgroundAim of the present paper is to report the preliminary results of CAD-CAM (Computer-Aided Design - Computer-Aided Manufacturing) technology application to distal femur nonunion treatment with free fibula flap, custom made medial plating and maintenance of a stable lateral locking plate. MethodsTwo cases of distal femur nonunion that occurred after lateral locking plating were treated and prospectively followed-up. Surgical planning followed the same preoperative protocol adopted for mandibular CAD-CAM reconstruction. Wide cutting sections were planned to obtain radical debridement. The tailored custom-made plate, a 3D rendering of bone defect and the cutting guides were produced and sterilized. Surgical intervention was conducted by steps (medial approach, bone resection, recipient vessels isolation, fibula harvesting and cutting, plate-fibula construct assembly, microvascular anastomosis, final fixation). ResultsThe mean follow-up was 13 (12-15) months. Bone union was achieved in both cases at mean 3.1 months. Full weight bearing without referred pain or discomfort was reached in both cases at mean 8,5 months (range 7 – 10). No complications occurred. ConclusionsCAD-CAM technology proved to be useful and reliable in custom made medial plating combined with free fibula transfer for the treatment of distal femur nonunion after lateral locking plating. Trial registrationnone.

Deep Learning Detection of Hand Motion During Microvascular Anastomosis Simulations Performed by Expert Cerebrovascular Neurosurgeons

Deep learning enables precise hand tracking without the need for physical sensors, allowing for unsupervised quantitative evaluation of surgical motion and tasks. We quantitatively assessed the hand motions of experienced cerebrovascular neurosurgeons during simulated microvascular anastomosis using deep learning. We explored the extent to which surgical motion data differed among experts. A deep learning detection system tracked 21 landmarks corresponding to digit joints and the wrist on each hand of 5 expert cerebrovascular neurosurgeons. Tracking data for each surgeon were analyzed over long and short time intervals to examine gross movements and micromovements, respectively. Quantitative algorithms assessed the economy and flow of motion by calculating mean movement distances from the baseline median landmark coordinates and median times between sutures, respectively. Tracking data correlated with specific surgical actions observed in microanastomosis video analysis. Economy of motion during suturing was calculated as 19, 26, 29, 27, and 28 pixels for surgeons 1, 2, 3, 4, and 5, respectively. Flow of motion during microanastomosis was 31.96, 29.40, 28.90, 7.37, and 47.21seconds for surgeons 1, 2, 3, 4, and 5, respectively. Hand tracking data showed similarities among experts, with low movements from baseline, minimal excess motion, and rhythmic suturing patterns. The data revealed unique patterns related to each expert's habits and techniques. The results showed that surgical motion can be correlated with hand motion and assessed using mathematical algorithms. We also demonstrated the feasibility and potential of deep learning-based motion detection to enhance surgical training.

First Clinical Microvascular Anastomosis Reported and the Importance of Updating Historical Records.

First Clinical Microvascular Anastomosis Reported and the Importance of Updating Historical Records.

Usefulness of using the superficial temporal pedicle as the recipient site for microvascular anastomosis in facial reconstruction: A retrospective study of 94 cases

In cranio-cervico-facial reconstructive surgery, it is accepted that the use of free flaps is the treatment of choice. The multiple antecedents can place the surgeon in situations of vascular deserts. The aim of our study is to report and analyse our experience of the use of temporal vessels in primary and secondary reconstructive surgery. A retrospective study was conducted between 01/01/2010 and 31/03/2023. Patients who underwent cranio-cervico-facial reconstruction using free flaps, with use of the superficial temporal pedicle as the recipient site for the vascular anastomosis were included. Early and late complication and failure rates were analysed according to type of reconstruction, location and risk factors for free flap failure. A total of 94 patients underwent craniocervical-facial reconstruction using a free flap anastomosed to the superficial temporal pedicle (in primary or secondary situations). Ten patients underwent reconstruction of the upper third, 58 the middle third and 26 the lower third. With an overall complication rate of 28.7% (21.3% minor complications and 7.4% major complications). Our study proves the reliability of the superficial temporal pedicle, both in the primary situation (with a success rate of 93.9%) and in the secondary situation (with a success rate of 89.3%), as well as its versatility whatever the cranio-cervico-facial level to be reconstructed. This study demonstrates the value of preserving the superficial temporal pedicle in craniofacial reconstruction surgery. This is because it is a preferred recipient site for reconstructions of the upper and middle thirds in the primary situation or in the event of recourse.

Comparison of Multiple-U and Simple Interrupted Suture Techniques in Microvascular Anastomosis: An Experimental Study in Male Albino Rats

Comparison of Multiple-U and Simple Interrupted Suture Techniques in Microvascular Anastomosis: An Experimental Study in Male Albino Rats

Validation of a dynamic 4D microsurgical bypass simulator for training and teaching microvascular anastomosis techniques with blood flow and fluorescence imaging

ObjectiveMicrovascular anastomosis is challenging, and training surgeons to develop and maintain skills is imperative. Current training models either miss the simulation of the surgical workflow, lack 3D key-hole space, need ethical approval, require special preparation, or lack realism. To circumvent these issues, this study describes the use of a mixed reality 3D printed model with integrated blood flow for training cerebral anastomosis and assesses its validity. MethodsDifferent-sized 3D-printed artificial micro artery models in a 3D brain space with a keyhole opening were used. The model was connected to a 4D simulator to induce pulsatile blood flow. Neurosurgical microscopes and exoscopes were used for visualization. Nine participants (n = 6 board-certified cerebrovascular neurosurgeons; n = 3 in-training) participated in the study and practiced anastomosis techniques with the simulator. Two senior, experienced vascular neurosurgeons mentored live teaching activity on the simulator. Participants completed a survey to score the face and content validity of the simulation on a 5-point Likert scale. Simulation time and anastomosis score differences between in-training and board-certified participants were compared for construct validity. ResultsParticipants scored the simulation difficulty similar to actual surgery, proving face validity. All participants agreed that practice on the provided simulator models would improve bypass techniques (μ = 4.67/5 ± 0.47) and instrument handling (μ = 4.56/5 ± 0.68). Board-certified participants had better anastomosis scores than in-training participants (non-significant difference). ConclusionsThe 4D simulator and the high-fidelity artificial 3D printed model effectively simulated actual bypass surgery in a key-hole fashion with blood flow abilities. Limited resources and preparation time are needed for the training setup. The model provides benefits in learning and maintaining anastomosis skills and allows for easy adaptation to different microanatomical scenarios.

Artery first and declamp it: A temporary revascularization method during microvascular anastomosis: A retrospective case series study

BackgroundThe optimal sequence of microvascular clamping during free flap transfer is yet to be established. Many surgeons are reluctant to perform temporary declamping and subsequent reclamping in the process of microvascular anastomosis; however, we usually anastomose the artery first and temporarily declamp it before venous anastomosis to confirm arterial patency and ensure proper alignment of the flap veins. Herein, we aimed to investigate the efficacy and safety of this temporary revascularization method retrospectively in 126 patients who underwent microvascular head and neck reconstruction. MethodsA total of 127 free flaps were transferred, with the anterolateral thigh flap being the most frequently used (49 flaps). The internal jugular vein was the most frequently used recipient vein, and an end-to-side anastomosis to it was performed in 112 patients. ResultsIntraoperative re-anastomosis was required because of an arterial thrombosis in five cases (4.0%), arterial and venous thrombosis in one case (0.8%), injury of the flap artery distal to the anastomotic site in one case (0.8%), and venous twisting in one case (0.8%). Postoperatively, all the flaps survived without microvascular compromise. ConclusionsVascular kinking or twisting of the vascular pedicle is a major cause of free flap failure. However, it is difficult to place empty vessels during clamping accurately. Temporary revascularization engorges the flap vein before venous anastomosis and minimizes the risk of venous kinking and twisting. According to our results, reclamping did not increase the risk of arterial thrombosis.

Interposition of Free Vascularized Fascia Into the Trapezial Resection Cavity for the Surgical Treatment of Trapeziometacarpal Osteoarthritis.

Trapeziometacarpal osteoarthritis has been treated with interposition of autologous fascia into the trapezial resection cavity to prevent scaphometacarpal impingement with suboptimal results. Autologous fascia may undergo necrosis and gradual shrinkage due to avascularity. We propose vascularization of the interposed fascia using microvascular techniques as a new alternative to achieve a durable graft with sufficient soft tissue volume. In this retrospective study, 11 surgeries for 8 patients (6 women, 2 men) (5 primary and 6 revision cases) were performed using vascularized fascial grafts from the anterolateral thigh for interposition in the trapezial resection cavity with microvascular anastomosis for revascularization. Subjective assessment included the short version of the Quick Disabilities of the Hand, Shoulder and Arm and patient related hand wrist evaluation scores. Objective assessment included strength and range of motion measurements. Radiographs were obtained preoperatively and at each follow-up visit. An MRI was done at a mean of 19 months postoperatively. The size of the harvested fascial grafts was 2 × 2-3 cm with a thickness of 1.5-2 cm. There were no postoperative complications apart from one seroma in the graft harvest site. The mean clinical and radiologic follow-up was 2 years and 8 months. The procedure provided pain relief PRWHE pain 32 (SD 13)-9 (SD 12), p < 0.0001, increased tip pinch strength 4 kg (SD3)-6 kg (SD2), p < 0.05, and improved overall function PRWHE 60 (SD28)-16 (SD21), p < 0.0001 and QuickDash 50 (SD21)-13 (SD17), p < 0.0001. Radiographs demonstrated maintenance of the scaphometacarpal space, while MRI scans showed the presence of mildly edematous interposed tissue within the resection cavity. Although technically demanding, vascularized fascia presents an attractive alternative for the treatment of trapeziometacarpal osteoarthritis. It may be particularly advantageous in complex cases requiring revision surgery and in young patients with high functional demands.

Impact of Suturing Techniques on Microvascular Anastomosis Maturation.

INTRODUCTION Microvascular anastomosis using interrupted suture is a widely accepted standard technique. Continuous suture is less common due to the presumption that its firmness can negatively affect anastomosis maturation. The purpose of this study was to determine whether the use of continuous suture allows maturation of the microanastomosis site. MATERIAL AND METHODS A rat common carotid artery (CCA) end-to-end microanastomosis model was utilized, with 19 Long-Evans rats in the interrupted sutures group and 13 in the continuous suture group. Immediate blood flow of the operated and contralateral intact CCAs was compared before clamping, at the completion of the anastomosis and after 14 days. Quantitative transit time flowmetry measurement and histological examination were employed. RESULTS Initial blood flow in both intact CCAs was similar across all animals (p = .004). In the interrupted suture group, median anastomosis blood flow was 88.9% of the contralateral CCA blod flow, with a median suture time of 46 minutes. After two weeks, blood flow increased to 96.1%. In the continuous suture group, median anastomosis blood flow was 88.3% of the contralateral CCA blood flow, with a median suture time of 30 minutes. After two weeks, blood flow increased to 100.0%. The reduction in suture time achieved with continuous suture was 34.8% (p < .001). Histological examination confirmed scar maturity. CONCLUSIONS The maturation rates of continuous and interrupted suture microanastomosis were comparable in our study, implying that concerns about the suture restricting maturation may be unwarranted. Additional finding is the potential for a reduction in microanastomosis time when using the continuous suture technique.

Scalp Reconstruction With Free Tissue Transfer Using Descending Branch of Lateral Circumflex Femoral Vessels as Interposition Graft.

Despite the rich blood supply to the scalp, postoperative skin necrosis at the surgical site sometimes occurs, and unresolved defects often present a significant challenge for the surgeon. When planning a free flap for scalp reconstruction, distant anastomoses may be necessary if local recipient vessels are unavailable due to previous surgery. This study presents the authors' treatment strategy, which includes extending the pedicle length with arteriovenous bundle interposition grafts. Two patients who experienced surgical wound necrosis after bypass surgery for moyamoya disease underwent reconstruction for skin and soft tissue coverage. To evaluate the altered anatomical structures after the previous surgery, three-dimensional computed tomography angiography was performed, and preoperative photos were taken to accurately measure the expected defect. The surgical strategy was designed to accommodate their unique conditions, utilizing an arteriovenous interposition graft, which included 2 stages of microvascular anastomoses, for pedicle lengthening. The procedure successfully bridged the gap between distant recipient vessels and the extensive defect, and the wounds healed without major complications such as venous congestion or total flap loss. Both patients were satisfied with the surgical outcomes. Arteriovenous bundle interposition grafts can be a useful option for patients with complex scalp defects who lack local recipient vessels. The use of an anterolateral thigh flap with artery-to-artery anastomosis, utilizing the lateral circumflex femoral artery from the opposite side in this study, offers many advantages compared with traditional pedicle lengthening tools utilizing vein-to-artery anastomosis.

Efficiency and safety of microvascular anastomotic coupler for wrist revascularization in traumatic injuries

IntroductionEffective vascular anastomosis is crucial for successful hand surgery, particularly in traumatic injuries where rapid restoration of blood flow is essential. The Synovis microvascular anastomotic coupler system presents a novel approach by potentially offering faster and more reliable outcomes than traditional suturing methods. This study was conducted to assess the effectiveness and safety of the Synovis coupler for microvascular anastomoses in the wrist, evaluating anastomosis time, patency rates, and complication rates. MethodsThis retrospective study examined 25 microvascular anastomoses (22 arteries and 3 veins) in 24 patients at a major trauma center. The primary outcomes measured were anastomosis time and vascular patency, which were assessed immediately post-operation and at subsequent follow-ups. ResultsThe average time required for anastomosis using the coupler was 7.3 min. Immediate post-operative vascular patency was 100%, with a long-term patency rate of 88%. Complications included arterial narrowing at the coupler site in 3 arteries, and complete occlusion in 3 arteries, accounting for a 12% long-term complication rate. ConclusionAlthough the Synovis coupler demonstrated a significant reduction in anastomosis time and high patency rates, our data suggest that its effectiveness is more pronounced in venous anastomoses. The higher complication rates in arterial anastomoses warrant cautious use in these cases. Further research, including prospective randomized controlled trials, is needed to validate these findings and optimize patient selection criteria for using couplers in microvascular surgery.

Ideal suturing technique for robot-assisted microsurgical anastomoses

The development of novel robotic devices specifically designed for open microsurgery leads to increasing applications in reconstructive procedures. While initial studies revealed improved precision and surgical ergonomics upon robotic assistance, surgical time was consistently observed to be increased. This study compares two robotic suturing techniques using the Symani Surgical System and RoboticScope in a preclinical setting, to further leverage the benefits of novel robotic devices in microsurgery. Six experienced microsurgeons performed three microvascular anastomoses with a “steady-thread” suturing technique and a “switch-thread” technique on 1.0-mm-diameter artificial silicone vessels. Time for anastomosis and participant’s satisfaction with the techniques and robotic setup were recorded. Anastomosis quality and microsurgical skills were assessed using the Anastomosis Lapse Index and Structured Assessment of Microsurgery Skills. Lastly, technical error messages and thread ruptures were quantified. Knot tying was significantly faster and evaluated significantly better by participants using the steady-thread technique (4.11 ± 0.85 vs. 6.40 ± 1.83 min per anastomosis). Moreover, microsurgical skills were rated significantly better using this technique, while both techniques consistently led to high levels of anastomosis quality (2.61 ± 1.21 vs. 3.0 ± 1.29 errors per anastomosis). In contrast, the switch-thread technique was associated with more technical error messages in total (14 vs. 12) and twice as many unintended thread ruptures per anastomosis (1.0 ± 0.88 vs. 0.5 ± 0.69). This study provides evidence for the enhanced performance of a steady-thread suturing technique, which is suggested to be applied upon robot-assisted microsurgical procedures for optimized efficiency.

Blunt Trauma Induced Closed Femoral Bone Fracture in a Rat Model: Are Vessels Safe to Use for Microsurgery? Further Insight into the Zone of Injury Concept.

The study aims to investigate the zone of injury for major vessels after high-velocity traumas, as it is unclear whether avoiding vascular structures is necessary during microvascular anastomosis or how long it takes for them to be used again. This study uses Doppler ultrasonography and a rat model to evaluate the histopathological changes and flow velocity of major vessels in the zone of injury after high-velocity trauma with closed femoral bone fracture. Osteosynthesis was performed using an intramedullary wire. Samples were collected from day 3 and week 3. The unaffected contralateral side is used as control. Results from arterial and venous flow assessments showed no evidence of ischemia in the extremities. Both arteries and veins were patent in both intervals and on the control side. The evaluation of the vessels showed arterial injury with a slightly reduced arterial flow on day 3 and week 3. The venous flow was slightly reduced on day 3 but not on week 3. Statistically, arterial endothelial injury was higher on day 3 than on week 3 (p = 0.006). Media inflammation was also higher on day 3 (p = 0.06). Arterial endothelization distribution was higher in week 3 (p = 0.006). No significant differences were found in arterial media irregularity, necrosis, platelet aggregation, bleeding, and wall rupture. Venous samples showed no significant differences in any parameter (p < 0.05). High-velocity trauma increases the risk of thrombosis in vessels. Intravascular repair can start on day 2 and continue till week 3 with significant endothelization. Although physiologic findings do not alter arterial or venous flow, histologic findings support vessel injuries leading to potential complications. Microsurgery should be considered out of the injury zone until adequate vessel healing is achieved.

The Use of Technology-Based Simulation among Medical Students as a Global Innovative Solution for Training.

Technological advancements have been rapidly integrated within the neurosurgical education track since it is a high-risk specialty with little margin for error. Indeed, simulation and virtual reality during training can improve surgical performance and technical skills. Our study aims to investigate the impact of neurosurgical technology-based simulation activities on medical students. The "Suturing Mission-The Symposium" was a three-day event held at Humanitas University. Participants had access to live-streamed conferences held by worldwide experts in several fields of neurosurgery and practical simulations of dura mater sutures, microvascular anastomosis, and augmented reality neurosurgical approaches. An anonymous survey was conducted at the beginning and end of the event. 141 medical students with a mean age of 21 participated. After the course, 110 participants (77.5%) showed interest in pursuing a surgical path, with a great prevalence in those who had planned to have a surgical career before the event (88.7% vs. 41.4%, p < 0.001). Participants were also asked about their comfort levels while handling surgical instruments, and a good outcome was reached in 72.7% of participants, with a significant difference between those who had previously attended a suture course (87.8% vs. 66.3%, p = 0.012). Training sessions on surgical simulators were effective in increasing participants' interest in pursuing a surgical path, improving their understanding of postgraduate orientation, and boosting their confidence with surgical instruments.