Safety and efficacy of Mynx vascular closure device for the closure of common femoral artery access after ipsilateral stent placement.

INTRODUCTION: To evaluate the feasibility and safety of the Mynx vascular closure device (VCD) for arteriotomy closure after stent placement near the common femoral artery (CFA) access site. METHODS: A total of 88 patients (73 men; mean age, 72 ± 9.2 years; 136 procedures) who underwent closure of CFA arteriotomy using the Mynx VCD after stent placement in proximal superficial femoral artery (SFA) with antegrade approach, or in common or external iliac artery with retrograde approach were retrospectively studied. Technical success and access site complication were evaluated. Body mass index (BMI), platelet count, international normalized ratio, prior history of ipsilateral CFA access, access direction, degree of CFA calcification, stent location and diameter, total procedure time, and sheath size were analyzed to evaluate their relationship with technical failure and development of bleeding complications. RESULTS: Technical success was achieved in 94.9% (129/136) patients. The mean time to hemostasis was 0.7 ± 1.8 min. Technical failure was significantly associated with low BMI (p = 0.001). Other variables presented no significant relationship with technical failure and development of complications. Ultrasonography on the day after the procedure revealed that 8 (5.9%) patients had hematoma. CONCLUSIONS: Mynx VCD for arteriotomy closure is feasible and provides hemostatic safety after stent placement near antegrade or retrograde CFA access. However, Mynx VCD may have a poor technical success rate among patients with low BMI.

Expedient Endovascular Hemorrhage Control During Anterior Lumbar Spinal Exposure Allows Procedural Completion in Rescued Patients.

OBJECTIVES: To propose a contemporary management strategy for venous injury during anterior lumbar spinal exposure that incorporates endovascular treatment. METHODS: Vein injuries suffered by patients treated in a single practice were reviewed. A treatment algorithm based on these experiences was formulated. RESULTS: Between 2015 and 2018, 914 patients received anterior access procedures for indicated lumbar interbody fusions. Of these patients, 15 (1.6%) suffered minor vascular injuries treated with manual pressure or suture repair. Four (0.4%) patients undergoing anterior lumbar spine surgery suffered major venous injuries, all of whom received the indicated spinal hardware following endovascular rescue. Primary repair was attempted in three patients before endovascular control and not at all in one. Vascular access was obtained via the bilateral femoral veins in 2 patients, unilateral femoral in one, and bilateral femoral plus right internal jugular vein in one. Stent choice included both uncovered (5, 63%) and covered stents (3, 38%). Deep venous thrombosis occurred in 2 patient's post-treatment. 1 DVT was encountered in the setting of a covered stent and 1 uncovered stent thrombosis was treated with catheter-directed lysis 4 weeks post-operatively. Ultimately, 3 patients were therapeutically anticoagulated. Mean follow-up is 13 months (range 1-36) with duplex ultrasounds available at 6 months or later in 3 of 4 patients. There is no evidence of post-thrombotic syndrome in the 2 patients that developed DVT's or in-stent stenosis in the 3 patients with available follow-up imaging. CONCLUSIONS: Endovascular techniques are important adjuncts when controlling large-volume hemorrhage associated with venous tears during anterior spinal exposure. Adequate direct compression allowing occlusion balloon inflation are key steps to reduce blood loss. Covered and uncovered stents are both appropriate choices to treat injuries. Patients must be anticoagulated post-operatively and surveilled for the sequelae of venous insufficiency. With expedient hemostasis, the indicated spinal surgery may be safely completed.

Sheath Size Up and Down With Single Proglide - A Technique for Achieving Hemostasis With Use of Large Size Delivery System During Endovascular Graft Placement.

BACKGROUND: A total percutaneous approach for management of aortic pathologies with endovascular grafts requires the use of large size delivery-systems. The diameter of these delivery systems usually exceeds the recommended sizes for most of the currently available percutaneous closure devices. A safe, effective and simple vascular access site closure device is desirable for success for percutaneous procedures for aortic pathologies. Hence, we aim to study safety and effectiveness of the use of a single suture based vascular access closure device (ProGlide) using a technique involving serial up and downsizing of the sheath size to achieve access site hemostasis in patients undergoing endovascular graft placement using femoral artery approach. MATERIALS AND METHODS: We studied all consecutive patients who underwent endovascular grafting from January 2018 to December 2019. It is a retrospective observational study comparing procedural and short-term outcomes between single ProGlide use and surgical cut-down for femoral access site closure. We excluded patients with femoral artery minimal luminal diameter less than 5 mm, the presence of an aneurysm of the femoral artery, ≥180 degrees of calcium present at femoral/ external iliac artery and history of any vascular closure device use in the last six months. RESULTS: We included 30 patients in single ProGlide group and 30 patients in the surgical cut-down group. One-third of the procedures were urgent procedures in the single Proglide group. Single ProGlide was successful in 93.34% patients and failure (6.66%) was seen due to hematoma and pseudoaneurysm in one patient each detected before discharge. The primary end-point defined by the success of procedure did not differ between the two groups. There were higher complications in the surgical group till 30 days as evidenced by infection, hematoma and neuronal injury. The secondary end-point, defined by the composite of complication events after discharge till 30 days was significantly higher in the surgical group (P-0.005) CONCLUSION: In patients with suitable femoral artery anatomy who undergo endovascular graft placement, effective hemostasis can be achieved safely using up and downsizing of the sheath with a single suture-based technique (Proglide). The results of the study could be considered hypothesis generating and needs to be confirmed in a randomized controlled trial before being adopted in clinical practice.

Alternative sources of cautery may improve post-operative hematoma rates but increase operative time in thyroid surgery.

A retrospective risk-adjusted analysis was completed using data from the National Surgical Quality Improvement Program (NSQIP) to (1) compare the risks of post-operative hematoma for thyroid surgery using conventional cautery compared alternative energy devices (defined as LigaSure and Harmonic Scalpel), and (2) compare operative times for the same. The primary outcome variable was post-operative hematoma occurrence. The secondary outcome variable was operative time. The exposure variable was use of conventional or alternative sources of cautery. All adult patients who underwent a total thyroidectomy, subtotal thyroidectomy or completion thyroidectomy between 2016 and 2018 were included. Multivariable linear and logistic regression analyses were performed to control for potentially confounding variables. A total of 13,330 cases were analyzed; 4342 used conventional cautery, and 8988 used alternative sources. There was a statistically significant decrease in post-operative hematoma risk using alternative sources of cautery compared to conventional cautery (OR 0.75; 95% CI 0.58-0.98) (p = 0.04). Use of alternative sources of cautery added 4.95 min onto operative time (95% CI 2.45-7.45) which was statistically significant (p < 0.0001). After controlling for confounding variables, there was a statistically significant lower rate of post-operative hematoma in thyroidectomies performed using alternative sources of cautery compared to those performed with traditional hemostatic methods. Alternative sources of cautery increased operative time by 4.95 min.

Efficacy of the hemostatic device VasoSTAT and the study of hemostatic factor.

Recently, trans-radial intervention has gained popularity as a common procedure to reduce hemorrhagic complications. However, the cuff-type hemostatic device (TR Band) previously used at our institution required 6 h to achieve hemostasis. Since July 2016, we have been using the VasoSTAT, a new hemostatic device that could achieve hemostasis in 4 h. In a verification study, we found that prolonged activated clotting time (ACT) was related to transient hemorrhage occurrence after the hemostatic procedure. Therefore, we designed a hemostatic protocol based on ACT and evaluated its efficacy. In this retrospective and observational study, 78 and 111 patients used the VasoSTAT and TR Band, respectively, from July 2015 to May 2017. In the VasoSTAT group, the ACTs were significantly lower in the hemostasis success (246 ± 46 s) than in the failure group patients (327 ± 59 s) (P < 0.01). Therefore, we applied the hemostatic protocol to 271 patients from May 2017 to March 2020. The hemostasis success rate was 96% in the post-protocol applied group patients, which was significantly higher than the 82% success rate in the pre-protocol applied group patients (P < 0.01). VasoSTAT resulted in adequate hemostasis in 4 h. Further, ACT was predictive of adequate hemostasis.

Microchannelled alkylated chitosan sponge to treat noncompressible hemorrhages and facilitate wound healing.

Developing an anti-infective shape-memory hemostatic sponge able to guide in situ tissue regeneration for noncompressible hemorrhages in civilian and battlefield settings remains a challenge. Here we engineer hemostatic chitosan sponges with highly interconnective microchannels by combining 3D printed microfiber leaching, freeze-drying, and superficial active modification. We demonstrate that the microchannelled alkylated chitosan sponge (MACS) exhibits the capacity for water and blood absorption, as well as rapid shape recovery. We show that compared to clinically used gauze, gelatin sponge, CELOX™, and CELOX™-gauze, the MACS provides higher pro-coagulant and hemostatic capacities in lethally normal and heparinized rat and pig liver perforation wound models. We demonstrate its anti-infective activity against S. aureus and E. coli and its promotion of liver parenchymal cell infiltration, vascularization, and tissue integration in a rat liver defect model. Overall, the MACS demonstrates promising clinical translational potential in treating lethal noncompressible hemorrhage and facilitating wound healing.

A chitosan hydrogel sealant with self-contractile characteristic: From rapid and long-term hemorrhage control to wound closure and repair.

Emergent and long-term hemorrhage control is requisite and beneficial for reducing global mortality and postoperative complications (e.g., second bleeding and adverse tissue adhesion). Despite recent advance in injectable hydrogels for hemostasis, achieving rapid gelation, strong tissue-adhesive property and stable mechanical strength under fluid physiological environment is still challenging. Herein, we developed a novel chitosan hydrogel (CCS@gel) via dynamic Schiff base reaction and mussel-inspired catechol chemistry. The hydrogel possessed high gelation rate (<10 s), strong wet adhesiveness, excellent self-healing performance and biocompatibility. More importantly, the CCS@gel exhibited saline-induced contractile performance and mechanical enhancement, promoting its mechanical property in moist internal conditions. In vivo studies demonstrated its superior hemostatic efficacy for diverse anticoagulated visceral and carotid bleeding scenarios, compared to commercialized fibrin glue. The hydrogel-treated rats survived for 8 weeks with minimal inflammation and postoperative adhesion. These results revealed that the promising CCS@gel would be a facile, efficient and safe sealant for clinical hemorrhage control.

Efficacy of Vascular Closure Devices in Closing Large-Bore Sheath Arterial Sites after Treatment with Extracorporeal Life Support System.

BACKGROUND: We retrospectively evaluated vascular complications and wound infections after surgical or percutaneous transfemoral removal of temporary extracorporeal life support systems (ECLSs). METHODS: A total of 83 patients were weaned from ECLS between August 2015 and September 2020. We analyzed for a composite endpoint of vascular complications and wound infections requiring negative-pressure wound therapy. Patients were divided into two groups: percutaneous group using the MANTA vascular occlusion system (VCD; Teleflex, Morrisville, North Carolina, United States) (n = 23) and surgical group (n = 60). RESULTS: The median age in the entire cohort was 67 years. Vascular complications were seen in 20% (n = 12) in the surgical group and in 13% (n = 3) in the percutaneous group (p = 0.72). A total of 32% (n = 19) in the surgical group and 9% (n = 2) in the percutaneous group (p = 0.031) had wound infections. A composite endpoint of vascular complications and wound infections showed significantly more complications in the surgical group (52%, n = 31) as compared with the percutaneous group (22%, n = 5) (p = 0.020). The median duration in the intensive care unit was 13 days for the surgical group and 12 days for the percutaneous group without any significant difference in both groups (p = 0.93). CONCLUSIONS: Using the MANTA VCD for percutaneous removal of ECLS cannulas after weaning from ECLS is safe and reproducible. A composite endpoint of vascular complications and wound infections was significantly lower in the percutaneous removal group as compared with the surgical group.

Effectiveness of uterine tamponade devices for refractory postpartum haemorrhage after vaginal birth: a systematic review.

OBJECTIVES: To evaluate uterine tamponade devices' effectiveness for atonic refractory postpartum haemorrhage (PPH) after vaginal birth and the effect of including them in institutional protocols. SEARCH STRATEGY: PubMed, EMBASE, CINAHL, LILACS, POPLINE, from inception to January 2021. STUDY SELECTION: Randomised and non-randomised comparative studies. OUTCOMES: Composite outcome including surgical interventions (artery ligations, compressive sutures or hysterectomy) or maternal death, and hysterectomy. RESULTS: All included studies were at high risk of bias. The certainty of the evidence was rated as very low to low. One randomised study measured the effect of the condom-catheter balloon compared with standard care and found unclear results for the composite outcome (relative risk [RR] 2.33, 95% CI 0.76-7.14) and hysterectomy (RR 4.14, 95% CI 0.48-35.93). Three comparative studies assessed the effect of including uterine balloon tamponade in institutional protocols. A stepped wedge cluster randomised controlled trial suggested an increase in the composite outcome (RR 4.08, 95% CI 1.07-15.58) and unclear results for hysterectomy (RR 4.38, 95% CI 0.47-41.09) with the use of the condom-catheter or surgical glove balloon. One non-randomised study showed unclear effects on the composite outcome (RR 0.33, 95% CI 0.11-1.03) and hysterectomy (RR 0.49, 95% CI 0.04-5.38) after the inclusion of the Bakri balloon. The second non-randomised study found unclear effects on the composite outcome (RR 0.95, 95% CI 0.32-2.81) and hysterectomy (RR 1.84, 95% CI 0.44-7.69) after the inclusion of Ebb or Bakri balloon. CONCLUSIONS: The effect of uterine tamponade devices for the management of atonic refractory PPH after vaginal delivery is unclear, as is the role of the type of device and the setting. TWEETABLE ABSTRACT: Unclear effects of uterine tamponade devices and their inclusion in institutional protocols for atonic refractory PPH after vaginal delivery.

The quantra hemostasis analyzer compared to thromboelastography (TEG) in the surgical oncologic population: A prospective observational trial.

BACKGROUND: Management of coagulopathy during major oncologic surgery can be multifactorial and challenging. Viscoelastic assays (VEAs) can be useful in providing vital data about the mechanism of coagulopathy in these dynamic circumstances. OBJECTIVES: A prospective nonrandomized observational study with the aim of describing the coagulation parameters of patients undergoing major oncologic surgery using the Quantra® and TEG® 5000 systems. Our secondary objectives included the correlation between Quantra and TEG parameters, and the times to result for both technologies. METHODS: This study included 74 adults undergoing oncologic surgery with an anticipated blood loss of more than 500 ml. For each subject, whole blood samples for each device were collected at multiple points perioperatively for comparison. RESULTS: Correlation coefficients between Quantra and TEG parameters were 0.8 and above, indicating a very strong correlation (p < .001). Correlation coefficients between conventional laboratory tests and Quantra ranged from 0.74 to 0.83, indicating a moderate correlation (p < .001). The mean time to obtain results and total processing time was shorter for Quantra in comparison to TEG. CONCLUSIONS: Quantra parameters strongly correlated with TEG parameters; however, Quantra parameters were available in shorter amount of time as it is specifically designed as a closed point of care device.

Ultrasound-Guided Deployment of a Plug-Based Vascular Closure Device in Femoral Arteries with Calcified Plaque or Stenosis.

From January 2019 to January 2020, 106 patients (age, 64.8 ± 14.1 years; male, 63.2%) were included to retrospectively investigate the feasibility and safety of ultrasound-guided deployment of ExoSeal after femoral artery access. Baseline characteristics were not different except for age (P = .022), body mass index (P = .009), and diameter (P < .001) between the calcified plaque or stenosis (CS) group (n = 49) and non-CS group (n = 57). The overall technical and clinical success rates were 96.2% and 100%, respectively. The technical (CS group, 48/49; non-CS group, 54/57) and clinical success rates (100%), time to hemostasis (CS group, 3.21 ± 0.54 min; non-CS group, 3.39 ± 0.71 min), and complication rates (CS group, 1/49; non-CS group, 0/57) were not different between the 2 groups. ExoSeal seems to be safe to use under ultrasound guidance in the femoral arteries with CS.

Prehospital tourniquet use: An evaluation of community application and outcome.

BACKGROUND: There is substantial investment in layperson and first responder training involving tourniquet use for hemorrhage control. Little is known however about prehospital tourniquet application, field conversion, or outcomes in the civilian setting. We describe the experience of a metropolitan region with prehospital tourniquet application. METHODS: We conducted a retrospective cohort study characterizing prehospital tourniquet use treated by emergency medical services (EMS) in King County, Washington, from January 2018 to June 2019. Emergency medical services and hospital records were abstracted for demographics, injury mechanism, tourniquet details, clinical care, and outcomes. We evaluated the incidence of tourniquet application, who applied the device (EMS, law enforcement, or layperson), and subsequent course. RESULTS: A total of 168 patients received tourniquet application, an incidence of 5.1 per 100,000 person-years and 3.48 per 1,000 EMS responses for trauma. Tourniquets were applied for penetrating trauma (64%), blunt trauma (30%), and bleeding ateriovenous fistulas (7%). A subset was critically ill: 13% had systolic blood pressures of <90 mm Hg, 8% had Glasgow Coma Scale score of <13, and 3% had cardiac arrest. Among initial applications, 48% were placed by law enforcement, 33% by laypersons, and 18% by EMS. Among tourniquets applied by layperson or law enforcement (n = 137), EMS relied solely on the original tourniquet in 45% (n = 61), placed a second tourniquet in 20% (n = 28), and removed the tourniquet without replacement in 35% (n = 48). Overall, 24% required massive transfusion, 59% underwent urgent surgery, and 21% required vascular surgery. Mortality was 3% (n = 4). At hospital discharge, the tourniquet limb was fully functional in 81%, partially functional in 10%, and nonfunctional in 9%; decreased function was not attributed to tourniquet application. CONCLUSION: The high rate of application, need for urgent hospital intervention in a subset, and low incidence of apparent complication suggest that efforts to increase access and early tourniquet use can provide public health benefit. LEVEL OF EVIDENCE: Therapeutic, level IV.

A comparison of efficacy, efficiency, and durability in novel tourniquet designs.

BACKGROUND: Exsanguination due to extremity hemorrhage is a major cause of preventable traumatic deaths. Extremity tourniquet use has been shown to be safe and improve survival. The purpose of this study was to compare the efficacy, efficiency, and durability of the Generation 7 Combat Application Tourniquet (CAT; North American Rescue, Greer, SC), the Tactical Mechanical Tourniquet (TMT; Combat Medical Systems, Harrisburg, NC), and the SOF Tactical Tourniquet-Wide (SOFTT-W; Tactical Medical Solutions, Anderson, SC). METHODS: This study was a three-phase randomized, cross-over trial. In successive trials, subjects were timed during the application of each tourniquet to the upper and lower extremity. Following successful lower extremity application, subjects low crawled 25 ft and then were dragged 25 ft, after which effectiveness was reassessed, as defined by the cessation of distal pulses by Doppler ultrasound. RESULTS: In arm application, both the CAT and TMT had significantly less failure rates than the SOFTT-W (5.56%, 19.44%, 58.33%), with the CAT being the fastest tourniquet when compared with TMT and SOFTT-W (37.8 seconds, 65.01 seconds, 63.07 seconds). In leg application, the CAT had significantly less rates of failure when compared with the SOFTT-W, but there was no other significant difference between the tourniquets (27.78%, 44.44%, 61.11%). In addition, the CAT was significantly faster than both the TMT and SOFTT-W when applied to the leg (8.33 seconds, 40.96 seconds, 34.5 seconds). There was no significant difference in tourniquet failure rates between the three tourniquets after subject maneuvers in phase 3 (34.29%, 42.86%, 45.45%). DISCUSSION: The CAT is as effective as the TMT and significantly more effective than the SOFTT-W. In addition, the CAT demonstrated shorter application times than either the TMT or SOFTT-W. However, there was no significant difference between the three tourniquets in their ability to maintain pulselessness after subject maneuvers. LEVEL OF EVIDENCE: Care management, level II.

Increased Use of Prehospital Tourniquet and Patient Survival: Los Angeles Countywide Study.

BACKGROUND: Recent trends in prehospital tourniquet use remain underreported. In addition, the impact of prehospital tourniquet use on patient survival has not been evaluated in a population-level study. We hypothesized that prehospital tourniquets were used more frequently in Los Angeles County and their use was associated with improved patient survival. STUDY DESIGN: This is a retrospective cohort study using a database maintained by the Los Angeles County Emergency Medical Services Agency. We included patients who sustained extremity vascular injuries between October 2015 and July 2019. Patients were divided into the following study groups: prehospital tourniquet and no-tourniquet group. Our primary end point was in-hospital mortality. The secondary outcomes included 4- and 24-hour transfusion requirements and delayed amputation. RESULTS: A total of 944 patients met our inclusion criteria. Of those, 97 patients (10.3%) had prehospital tourniquets placed. The rate of tourniquet use increased linearly throughout our study period (goodness of fit, p = 0.014). In multivariable analysis, prehospital tourniquet use was significantly associated with improved mortality (adjusted odds ratio 0.32; 95% CI, 0.16 to 0.85; p = 0.032). Similarly, transfusion requirements were significantly lower within 4 hours (regression coefficient -547.76; 95% CI, -762.73 to -283.49; p < 0.001) and 24 hours (regression coefficient -1,389.82; 95% CI, -1,824.88 to -920.97; p < 0.001). There was no significant difference in delayed amputation rates (adjusted odds ratio 1.07; 95% CI, 0.21 to 10.88; p < 0.097). CONCLUSIONS: Prehospital tourniquet use has been on the rise in Los Angeles County. Our results suggest that the use of prehospital tourniquets for extremity vascular injuries is associated with improved patient survival and decreased blood transfusion requirements, without an increase in delayed amputations.

Delayed Complication Secondary to Unsuccessful Deployment of the StarClose Device.

The introduction of vascular closure devices (VCD) such as the StarClose device, has been an innovative step in interventional procedures. Earlier post-procedure ambulation, reduced hematoma formation, the time to hemostasis and the need for blood transfusion have been achievable.1 Few case reports describe complications following deployment of the StarClose device, resulting in acute ischemia. Here we present a unique case of unsuccessful deployment of the StarClose device in a patient following an elective right superficial femoral artery angioplasty, resulting in delayed deterioration of the patient's symptoms, necessitating surgery months after the initial intervention.

Closure device use for common femoral artery antegrade access is higher risk than retrograde access.

OBJECTIVE: Although the use of closure devices (CD) for femoral artery antegrade access (AA) is not in the instructions for use (IFU) for many devices, AA has been reported to be associated with a lower incidence of access site complications compared to manual compression alone. We hypothesized that CD use for AA would not be associated with a clinically significant increased odds of access site complications compared to CD use for retrograde access (RA). METHODS: This was a retrospective review of the Vascular Quality Initiative from 2010 to 2019 for infrainguinal peripheral vascular interventions with common femoral artery access closed with a CD. Patients who had a cutdown or multiple access sites were excluded. Cases were then stratified into whether access was antegrade or retrograde. Hierarchical multivariable logistic regressions controlling for hospital level variation were used to examine the independent association between AA and access site complications. The primary outcomes were access site hematoma, stenosis, or occlusion as defined in the VQI. The secondary outcome was the development of an access site hematoma requiring an intervention, which was defined as transfusion, thrombin injection, or surgery. Sensitivity analyses after coarsened exact matching were performed to reduce residual bias. RESULTS: Overall, 72,463 cases were identified and 6,070 (8.4%) had AA. Patients with AA were less likely to be smokers (27.2% vs 33.0%) or obese (31.5% vs 35.6%; all P<0.05). Patients with AA were more likely to be on dialysis (12.8% vs 10.1%) and have ultrasound-guided access (76.4% vs 66.2%; P<0.05 for all). Compared to RA, patients with AA were more likely to develop any access site hematoma (2.5% vs 1.8%; P<0.01) and a hematoma requiring intervention (0.7% vs 0.5%; P=0.03), but had no difference in access site stenosis or occlusion (0.3% vs 0.2%; P=0.21). On multivariable analyses, AA had increased odds of developing any access site hematoma (OR=1.46; 95% CI=1.22-1.76) and a hematoma requiring intervention (OR=1.48; 95% CI=1.10-1.98). Sensitivity analyses after coarsened exact matching confirmed these findings. CONCLUSION: In this nationally representative sample, the use of CDs for femoral access was associated with an overall low rate of access site complications. However, there was an increased odds of access site hematomas with AA. Patient selection for AA remains important and ultrasound guided access should be the standard of care for this approach.

Cadaver as an educational tool increasing the effectiveness of Combat Application Tourniquet use in extremity injuries.

BACKGROUND: One of the most frequent life-threatening emergencies is extremity haemorrhage. In such cases, patient survival depends on a fast on-scene intervention. Thus, both the potential witnesses and medical emergency staff should have the ability to control haemorrhages. However, simulator-based courses do not fully reflect the structures and physiology of the human body. Therefore, invasive procedure training in trauma patients is limited. The present study aims to evaluate the effectiveness of cadavers as educational tools during a training course in extremity haemorrhage control with the use of the Combat Application Tourniquet (CAT). METHODS: This study was conducted among 31 paramedic students, who applied a tourniquet to the upper extremity of an unembalmed (fresh) human cadaver with simulated bleeding. Two time measurements were performed, the latter being preceded by a short CAT application training on a human cadaver. RESULTS: The mean time needed to stop the simulated bleeding in the first attempt was 38.33 seconds (SD±35.14). After the training, the mean time decreased to 20.58 seconds (SD±5.77). A statistically significant difference was observed between these two values (p=0.004). CONCLUSION: This study demonstrated that training conducted on human cadavers led to a significant improvement in the effectiveness of CAT use. Cadavers constitute a high-quality educational tool that, after adequate preparation, allows for practicing invasive medical procedures, such as extremity haemorrhage control.

Hemostatic Needles: Controlling Hemostasis Time by a Catecholamine Oxidative Pathway.

Most infectious human viruses are generally found in the bloodstream after being released by infected organs. Thus, hemorrhage in patients, whose blood contains infectious viruses might be a significant risk for secondary infections. In this work, a self-sealing hemostatic needle that causes no bleeding even after its removal is reported. The materials used for the self-sealing needles are inspired by mussel adhesive polysaccharide, chitosan-catechol, which shows a rapid phase transition from a solid phase (i.e., a thin film) to an adhesive gel upon coming into contact with blood. We found that the self-sealing time for the complete hemostasis depends on the oxidation pathway of the conjugated catechol. For high-temperature oxidation (i.e., 60 °C), Michael addition is a dominant oxidative coupling reaction, which weakens the chitosan-catechol attachment force on the needle surface. Thus, the film is easily transferred to the hemorrhaging sites, with the result that there is no bleeding even after a short injection time (<5 s). In contrast, during low-temperature oxidation (4 °C), Schiff base formation is dominant, which strengthens the film attachment force on the needle surface, resulting in continued bleeding owing to a dearth of tissue transfer after the injection.