Hybrid repair of tandem high-grade innominate and carotid artery stenosis in an asymptomatic male

Tandem atherosclerotic lesions of the innominate artery (IA) and internal carotid artery (ICA) are challenging and represent an inherent risk of cerebrovascular accident. Treating asymptomatic patients is controversial; therefore, it is critical to minimize the risk of a cerebrovascular accident if repair is undertaken. An asymptomatic 78-year-old man with a chronically occluded left ICA and tandem stenoses of the IA and right ICA underwent a hybrid intervention with stenting of the IA lesion and right ICA endarterectomy. The intra- and postoperative course was successful, without any signs of neurological sequelae. Sixteen months later, the patient remained asymptomatic, with patent reconstructions.

Assessing the stops framework for coping with intraoperative errors: Evidence of efficacy, hints of hubris, and a bridge to abridging burnout

BACKGROUND

Answering calls in the literature, we developed and introduced an evidence-based tool for surgeons facing errors in the operating room: the STOPS framework (stop, talk to you team, obtain help, plan, succeed). The purpose of this research was to assess the impact of presenting this psychological tool on resident coping in the operating room and the related outcome of burnout while examining sex differences.

METHODS

In a natural experiment, general surgery residents were invited to attend 2 separate educational conferences regarding coping with errors in the operating room. Three months later, all residents were asked to fill out a survey assessing their coping in the operating room, level of burnout, and demographics. We assessed the impact of the educational intervention by comparing those who attended the coping conferences with those who did not attend.

RESULTS

Thirty-five residents responded to the survey (65% response rate, 54% female respondents, 49% junior residents). Our hypothesized moderated mediation model was supported. Sex was found to moderate the impact of the STOPS framework-female residents who attended the coping educational conference reported higher coping self-efficacy, whereas attendance had no statistically significant impact on male levels of coping self-efficacy. In turn, higher coping self-efficacy was associated with lower levels of burnout.

CONCLUSION

Our results suggest that there is evidence of efficacy in this instruction-female residents presented this material report higher levels of coping in the operating room compared to those who did not receive the framework. Further, increase in coping ability was associated with reduced levels of burnout for both genders.

Cryopreserved arterial allografts vs autologous vein for arterial reconstruction in infected fields

OBJECTIVE

Peripheral arterial infections are rare and difficult to treat when an in situ reconstruction is required. Autologous vein (AV) is the conduit of choice in many scenarios. However, cryopreserved arterial allografts (CAAs) are an alternative. We aimed to assess our experience with CAAs and AVs for reconstruction in primary and secondary peripheral arterial infections.

METHODS

Data from patients with peripheral arterial infections undergoing reconstruction with CAA or AV from January 2002 through August 2022 were retrospectively analyzed. Patients with aortic- or iliac-based infections were excluded.

RESULTS

A total of 42 patients (28 CAA, 14 AV) with a mean age of 65 and 69 years, respectively, were identified. Infections were secondary in 31 patients (74%) and primary in 11 (26%). Secondary infections included 10 femoral-femoral grafts, 10 femoropopliteal or femoral-distal grafts, five femoral patches, four carotid-subclavian grafts, one carotid-carotid graft, and one infected carotid patch. Primary infection locations included six femoral, three popliteal, and two subclavian arteries. In patients with lower extremity infections, associated groin infections were present in 19 (56%). Preoperative blood cultures were positive in 17 patients (41%). AVs included saphenous vein in eight and femoral vein in six. Intraoperative cultures were negative in nine patients (23%), polymicrobial in eight (21%), and monomicrobial in 22 (56%). Thirty-day mortality occurred in four patients (10%), two due to multisystem organ failure, one due to graft rupture causing acute blood loss and myocardial infarction, and one due to an unknown cause post-discharge. Median follow-up was 20 months and 46 months in the CAA and AV group, respectively. Graft-related reintervention was performed in six patients in the CAA group (21%) and one patient in the AV group (7%). Freedom from graft-related reintervention rates at 3 years were 82% and 92% in the CAA and AV group, respectively (P = .12). Survival rates at 1 and 3 years were 85% and 65% in the CAA group and 92% and 84% in the AV group (P = .13). Freedom from loss of primary patency was similar with 3-year rates of 77% and 83% in the CAA and AV group, respectively (P = .25). No patients in either group were diagnosed with reinfection.

CONCLUSIONS

CAAs are an alternative conduit for peripheral arterial reconstructions when AV is not available. Although there was a trend towards higher graft-related reintervention rates in the CAA group, patency is similar and reinfection is rare.

Laparoscopic Median Arcuate Ligament Release: Surgical Technique and Clinical Outcomes

BACKGROUND

Median arcuate ligament syndrome (MALS) is characterized by a constellation of symptoms related to the compression of the celiac artery trunk. Laparoscopic release of the ligament has demonstrated its effectiveness in alleviating these symptoms while showing lower postoperative complication rates, reduced hospital stays, and improved clinical outcomes. This study describes a single institution's experience with this procedure and reports on the preoperative assessment, surgical technique, and clinical outcomes of patients with MALS.

METHODS

We performed a retrospective chart review of all patients who underwent a primary laparoscopic MAL release (MALR) at a single high-volume academic institution from June 2021 to July 2023. Patient demographics, preoperative assessment, postoperative complications, and resolution of preoperative symptoms data were collected.

RESULTS

A total of 30 patients underwent laparoscopic MALR, with 76.7% being female and a mean age of 33.4±16.3 years. The most common presenting symptom was postprandial epigastric pain (100%), followed by abdominal pain and nausea (83.3%), among others. The preoperative evaluation for all patients included a duplex mesenteric doppler and CT angiogram during inspiration and expiration and 3D reconstruction. Successful laparoscopic decompression of the celiac artery was achieved in 96.6% of cases, with only one conversion to an open procedure. There was only one reported early (<30 d postoperatively) complication with no subsequent late complications or mortality. None of the patients required reintervention or reoperation. Only 1 patient required postoperative celiac plexus/splanchnic block injection to alleviate pain.

CONCLUSIONS

MALS can be effectively and safely managed using a laparoscopic approach when performed by an experienced minimally invasive surgeon. Further studies with longer follow-ups are needed to confirm the long-term effectiveness of this technique.

Outcomes of lower extremity arterial bypass using the Human Acellular Vessel in patients with chronic limb-threatening ischemia

OBJECTIVE

Patients with chronic limb-threatening ischemia (CLTI) and no great saphenous vein to use as a conduit for arterial bypass have a high risk for amputation despite advances in medical and endovascular therapies. This report presents findings from a U.S. Food and Drug Administration (FDA) supported study of the Human Acellular Vessel (HAV) (Humacyte Inc.) used as a conduit for arterial bypass in patients with CLTI and inadequate or absent autologous conduit.

METHODS

The HAV is a 6-mm, 40-cm vessel created from human vascular smooth muscle cells seeded onto a polyglycolic acid scaffold pulsed in a bioreactor for 8 weeks as cells proliferate and the scaffold dissolves. The resultant vessel is decellularized, creating a nonimmunogenic conduit composed of collagen, elastin, and extracellular matrix. The FDA issued an Investigational New Drug for an intermediate-sized, single-center study of the HAV under the agency's Expanded Access Program in patients with advanced CLTI and inadequate or absent autologous conduit. Technical results and clinical outcomes were analyzed and reported.

RESULTS

Between March 2021 and July 2023, 29 patients (20 males; mean age, 71 ± 11 years) underwent limb salvage operation using the HAV as a bypass conduit. Most patients had advanced CLTI (Rutherford class 5/6 in 72%; wound, ischemia, and foot infection stage 3/4 in 83%), and 97% had previously failed revascularization(s) of the extremity. Two HAVs were sewn together to attain the needed bypass length in 24 patients (83%). Bypasses were to tibial arteries in 23 patients (79%) and to the popliteal artery in 6 (21%). Technical success was 100%, and the 30-day mortality rate was 7% (2 patients). With 100% follow-up (median, 9.3 months), the limb salvage rate was 86% (25/29 patients). There were 16 reinterventions to restore secondary patency, of which 15 (94%) were successful. Primary and secondary patency of the HAV at 9 months were 59% and 71%, respectively.

CONCLUSIONS

The HAV has demonstrated short- to intermediate-term safety and efficacy as an arterial bypass conduit in a complex cohort of patients with limb-threatening ischemia and no autologous options. This experience using the FDA's Expanded Access Program provides real-world data to inform regulatory deliberations and future trials of the HAV, including the study of the vessel as a first-line bypass conduit in less severe cases of chronic limb ischemia.

Outcomes of Arterial Bypass With the Human Acellular Vessel for Chronic Limb-Threatening Ischemia Performed Under the FDA Expanded Access Program

OBJECTIVE

To report outcomes of the human acellular vessel (HAV) implanted for limb salvage through the Food and Drug Administration (FDA) Expanded Access Program for patients with chronic limb-threatening ischemia with no autologous conduit.

METHODS

The HAV is a bioengineered vascular conduit designed with human vascular smooth muscle cells. The product is under regulatory study. From April 2019 to November 2021, the HAV was implanted in 14 patients (12 men; mean age, 62±14 years) at 3 US centers. Each case was performed with a single-use investigational new drug Expanded Access Program issued by the FDA. Institutional review board approval was obtained; technical and clinical outcomes were analyzed.

RESULTS

A single 6-mm-diameter (40-cm-long) HAV was implanted in 9 patients; 5 patients required 2 HAVs sewn together as a composite. Technical success was 100%. Median follow-up was 12 (range, 1 to 41) months. Primary and secondary patency rates were 72% and 81% at 12 months; assisted primary patency was attained in 4 patients. Amputation-free survival was 93% at 6 months and 77% at 12 months. All patients with a patent HAV experienced clinical improvement with no HAV-related infections or adverse events. There were 4 deaths in the cohort, late mortality unrelated to the HAV.

CONCLUSION

The HAV is a safe and effective "off-the-shelf" biologic conduit. This experience from the FDA Expanded Access Program in this population with few alternative limb salvage options will help guide regulatory deliberations for patients with lower extremity ischemia and no autologous bypass conduit options.

Implementation of a Brief Evidence-Based Intraoperative Coping Curriculum

BACKGROUND AND RATIONALE

Recent research has called for further resident training in coping with errors and adverse events in the operating room. To the best of our knowledge, there currently exists no evidence-based curriculum or training on this topic.

MATERIALS AND METHODS

Synthesizing three prior studies on how experienced surgeons react to errors and adverse events, we developed the STOPS framework for handling surgical errors and adverse events (Stop, Talk to your team, Obtain help, Plan, Succeed). This material was presented to residents in two teaching sessions.

RESULTS AND CONCLUSION

In this paper, we describe the presentation of, and the uniformly positive resident reaction to, the STOPS framework: an empirically based psychological tool for surgeons who experience operative errors or adverse events.

Use of MEDEVAC Resources in Austere Settings: Paget-Schroetter in the Deployed Environment

Medical evacuation (MEDEVAC) from a combat zone requires complex decision-making and coordination of assets. A MEDEVAC helicopter team transports not only battle-injured patients but also patients with urgent non-battle-related medical diagnoses from extremely remote locations and are at the mercy of terrain, weather, and enemy contact. The military represents a young population particularly susceptible to venous thoracic outlet syndrome (vTOS) given the rigorous physical activity demands. Current literature supports immediate anticoagulation and surgical decompression within 14 days of diagnosis of vTOS to prevent long-term morbidity. Presented is a case of service member with vTOS presenting at an extremely remote military clinic who underwent a prompt evacuation ∼7,000 miles utilizing rotary-wing transport, followed by three to four more fixed-wing flights to a military treatment facility in the United States. Immediate recognition and ultrasound of this patient to confirm vTOS upon presentation and effective communication to non-medical military commanders and the receiving medical personnel at each Echelon was necessary to ensure an expedited evacuation. The surgeons treating this patient recommend prompt evacuation of deployed service members with suspected vTOS, venogram at the Role 3 if ultrasound is inconclusive, anticoagulation, and return to a Role 4 CONUS facility for definitive surgical management within 14 days. This case is an example of the efficiency of the military MEDEVAC system on a global scale, ensuring optimum medical care for all service members deployed.

Cryopreserved Arterial Allografts Versus Rifampin-Soaked Dacron for the Treatment of Infected Aortic and Iliac Aneurysms

BACKGROUND

Infected aortic and iliac artery aneurysms are challenging to treat. Cryopreserved arterial allografts (CAAs) or rifampin-soaked Dacron (RSD) are standard options for in situ reconstruction. Our aim was to compare the safety and effectiveness of CAA versus RSD for these complex pathologies.

METHODS

This is a retrospective review of infected iliac, abdominal, and thoracoabdominal aortic aneurysms treated with either CAAs or RSD between 2002 and 2022 at our institution. The diagnosis was confirmed by intraoperative, radiologic, or microbiological evidence of aortic infection. Perioperative events, 30-day and long-term mortality, reinfection, and reintervention were analyzed.

RESULTS

Thirty patients (17 CAA, 13 RSD) with a mean age of 61 and 68 years, respectively, were identified. The infected aneurysm was most commonly suprarenal or infrarenal. Culture-negative infections were present in 47% of the CAA group and 54% in the RSD group. Early major morbidity was 57% and 54% for the CAA and RSD, respectively. Thirty-day mortality was similar between groups (18% vs. 23% CAA vs. RSD, P ≥ 0.99). Median follow-up was longer in the RSD group (14.5 months vs. 13 months). Overall survival at 1 and 5 years was 80.8% and 64.8% in the CAA group and 69.2% and 57.7% in the RSD group. Reinterventions only occurred with CAA repairs and indications included graft occlusion (2), multiple pseudoaneurysms and reinfection (1), and hemorrhagic shock caused by graft rupture (1). Freedom from reintervention at 1 and 3 years was 87.5% and 79.5% (CAA group) versus 100% and 100% (RSD, P = 0.06). Freedom from reinfection at 1 year was 100% in both groups, while at 3 years it was 90.9% for the CAA group and 100% for the RSD group (P = 0.39).

CONCLUSIONS

Infected aortic and iliac aneurysms have high early morbidity and mortality. CAA and RSD had similar outcomes in our series; CAA trended toward higher reintervention rates. Both remain viable options for complex scenarios but require close surveillance.

Radiomic-based Textural Analysis of Intraluminal Thrombus in Aortic Abdominal Aneurysms: A Demonstration of Automated Workflow

Our main objective is to investigate how the structural information of intraluminal thrombus (ILT) can be used to predict abdominal aortic aneurysms (AAA) growth status through an automated workflow. Fifty-four human subjects with ILT in their AAAs were identified from our database; those AAAs were categorized as slowly- (< 5 mm/year) or fast-growing (≥ 5 mm/year) AAAs. In-house deep-learning image segmentation models were used to generate 3D geometrical AAA models, followed by automated analysis. All features were fed into a support vector machine classifier to predict AAA's growth status.The most accurate prediction model was achieved through four geometrical parameters measuring the extent of ILT, two parameters quantifying the constitution of ILT, antihypertensive medication, and the presence of co-existing coronary artery disease. The predictive model achieved an AUROC of 0.89 and a total accuracy of 83%. When ILT was not considered, our prediction's AUROC decreased to 0.75 (P-value < 0.001).

Cryopreserved arterial allografts vs rifampin-soaked Dacron for the treatment of infected aortic and iliac grafts

OBJECTIVE

Aortic and iliac graft infections remain complex clinical problems with high mortality and morbidity. Cryopreserved arterial allografts (CAAs) and rifampin-soaked Dacron (RSD) are options for in situ reconstruction. This study aimed to compare the safety and effectiveness of CAA vs RSD in this setting.

METHODS

Data from patients with aortic and iliac graft infections undergoing in situ reconstruction with either CAA or RSD from January 2002 through August 2022 were retrospectively analyzed. Our primary outcomes were freedom from graft-related reintervention and freedom from reinfection. Secondary outcomes included comparing trends in the use of CAA and RSD at our institution, overall survival, perioperative mortality, and major morbidity.

RESULTS

A total of 149 patients (80 RSD, 69 CAA) with a mean age of 68.9 and 69.1 years, respectively, were included. Endovascular stent grafts were infected in 60 patients (41 CAA group and 19 RSD group; P ≤ .01). Graft-enteric fistulas were more common in the RSD group (48.8% RSD vs 29.0% CAA; P ≤ .01). Management included complete resection of the infected graft (85.5% CAA vs 57.5% RSD; P ≤ .01) and aortic reconstructions were covered in omentum in 57 (87.7%) and 63 (84.0%) patients in the CAA and RSD group, respectively (P = .55). Thirty-day/in-hospital mortality was similar between the groups (7.5% RSD vs 7.2% CAA; P = 1.00). One early graft-related death occurred on postoperative day 4 due to CAA rupture and hemorrhagic shock. Median follow-up was 20.5 and 21.5 months in the CAA and RSD groups, respectively. Overall post-discharge survival at 5 years was similar, at 59.2% in the RSD group and 59.0% in the CAA group (P = .80). Freedom from graft-related reintervention at 1 and 5 years was 81.3% and 66.2% (CAA) vs 95.6% and 92.5% (RSD; P = .02). Indications for reintervention in the CAA group included stenosis (n = 5), pseudoaneurysm (n = 2), reinfection (n = 2), occlusion (n = 2), rupture (n = 1), and graft-limb kinking (n = 1). In the RSD group, indications included reinfection (n = 3), occlusion (n = 1), endoleak (n = 1), omental coverage (n = 1), and rupture (n = 1). Freedom from reinfection at 1 and 5 years was 98.3% and 94.9% (CAA) vs 92.5% and 87.2% (RSD; P = .11). Two (2.9%) and three patients (3.8%) in the CAA and RSD group, respectively, required graft explantation due to reinfection.

CONCLUSIONS

Aorto-iliac graft infections can be managed safely with either CAA or RSD in selected patients for in situ reconstruction. However, reintervention was more common with CAA use. Freedom from reinfection rates in the RSD group was lower, but this was not statistically significant. Conduit choice is associated with long-term surveillance needs and reinterventions.

Military Medicine's Value to US Health Care and Public Health: Bringing Battlefield Lessons Home

Importance

Military medicine in the US was established to treat wounded and ill service members and to protect the health and well-being of our military forces at home and abroad. To accomplish these tasks, it has developed the capacity to rapidly adapt to the changing nature of war and emerging health threats; throughout our nation's history, innovations developed by military health professionals have been quickly adopted by civilian medicine and public health for the benefit of patients in the US and around the world.

Observations

From the historical record and published studies, we cite notable examples of how military medicine has advanced civilian health care and public health. We also describe how military medicine research and development differs from that done in the civilian world. During the conflicts in Afghanistan and Iraq, military medicine's focused approach to performance improvement and requirements-driven research cut the case fatality rate from severe battlefield wounds in half, to the lowest level in the history of warfare.

Conclusions and Relevance

Although innovations developed by military medicine regularly inform and improve civilian health care and public health, the architects of these advances and the methods they use are often overlooked. Enhanced communication and cooperation between our nation's military and civilian health systems would promote reciprocal learning, accelerate collaborative research, and strengthen our nation's capacity to meet a growing array of health and geopolitical threats.

The Human Acellular Vessel (HAV) as a vascular conduit for infrainguinal arterial bypass

Autologous vein is the optimal conduit for peripheral arterial bypass surgery, a standard recently highlighted by findings from the BEST-CLI trial. The Human Acellular Vessel is a novel biologic conduit produced using regenerative medicine technologies with structural and mechanical properties like a human blood vessel. Not yet approved by the United States Food and Drug Administration, the Human Acellular Vessel is being studied as an alternative bypass conduit in patients with peripheral arterial disease, vascular injury, and those in need of arteriovenous access for hemodialysis. This report describes and illustrates the technical aspects of intraoperative handling specific to the use of this new and innovative technology.

Characterization of small abdominal aortic aneurysms' growth status using spatial pattern analysis of aneurismal hemodynamics

Aneurysm hemodynamics is known for its crucial role in the natural history of abdominal aortic aneurysms (AAA). However, there is a lack of well-developed quantitative assessments for disturbed aneurysmal flow. Therefore, we aimed to develop innovative metrics for quantifying disturbed aneurysm hemodynamics and evaluate their effectiveness in predicting the growth status of AAAs, specifically distinguishing between fast-growing and slowly-growing aneurysms. The growth status of aneurysms was classified as fast (≥ 5 mm/year) or slow (< 5 mm/year) based on serial imaging over time. We conducted computational fluid dynamics (CFD) simulations on 70 patients with computed tomography (CT) angiography findings. By converting hemodynamics data (wall shear stress and velocity) located on unstructured meshes into image-like data, we enabled spatial pattern analysis using Radiomics methods, referred to as "Hemodynamics-informatics" (i.e., using informatics techniques to analyze hemodynamic data). Our best model achieved an AUROC of 0.93 and an accuracy of 87.83%, correctly identifying 82.00% of fast-growing and 90.75% of slowly-growing AAAs. Compared with six classification methods, the models incorporating hemodynamics-informatics exhibited an average improvement of 8.40% in AUROC and 7.95% in total accuracy. These preliminary results indicate that hemodynamics-informatics correlates with AAAs' growth status and aids in assessing their progression.

Computerized Differentiation of Growth Status for Abdominal Aortic Aneurysms: A Feasibility Study

Fast-growing abdominal aortic aneurysms (AAA) have a high rupture risk and poor outcomes if not promptly identified and treated. Our primary objective is to improve the differentiation of small AAAs' growth status (fast versus slow-growing) through a combination of patient health information, computational hemodynamics, geometric analysis, and artificial intelligence. 3D computed tomography angiography (CTA) data available for 70 patients diagnosed with AAAs with known growth status were used to conduct geometric and hemodynamic analyses. Differences among ten metrics (out of ninety metrics) were statistically significant discriminators between fast and slow-growing groups. Using a support vector machine (SVM) classifier, the area under receiving operating curve (AUROC) and total accuracy of our best predictive model for differentiation of AAAs' growth status were 0.86 and 77.50%, respectively. In summary, the proposed analytics has the potential to differentiate fast from slow-growing AAAs, helping guide resource allocation for the management of patients with AAAs.

Evaluation of vascular repair by tissue-engineered human acellular vessels or expanded polytetrafluoroethylene grafts in a porcine model of limb ischemia and reperfusion

BACKGROUND

This study evaluated performance of a tissue-engineered human acellular vessel (HAV) in a porcine model of acute vascular injury and ischemia. The HAV is an engineered blood vessel consisted of human vascular extracellular matrix proteins. Limb reperfusion and vascular outcomes of the HAV were compared with those from synthetic expanded polytetrafluoroethylene (ePTFE) grafts.

METHODS

Thirty-six pigs were randomly assigned to four treatment groups, receiving either the HAV or a PTFE graft following a hind limb ischemia period of either 0 or 6 hours. All grafts were 3-cm-long interposition 6-mm diameter grafts implanted within the right iliac artery. Animals were not immunosuppressed and followed for up to 28 days after surgery. Assessments performed preoperatively and postoperatively included evaluation of graft patency, hind limb function, and biochemical markers of tissue ischemia or reperfusion injury. Histological analysis was performed on explants to assess host cell responses.

RESULTS

Postoperative gait assessment and biochemical analysis confirmed that ischemia and reperfusion injury were caused by 6-hour ischemia, regardless of vascular graft type. Hind limb function and tissue damage biomarkers improved in all groups postoperatively. Final patency rates at postoperative day 28 were higher for HAV than for ePTFE graft in both the 0-hour (HAV, 85.7%; ePTFE, 66.7%) and 6-hour (HAV, 100%; ePTFE, 75%) ischemia groups, but these differences were not statistically significant. Histological analyses identified some intimal hyperplasia and host reactivity to the xenogeneic HAV and also to the synthetic ePTFE graft. Positive host integration and vascular cell infiltration were identified in HAV but not ePTFE explants.

CONCLUSION

Based on the functional performance and the histologic profile of explanted HAVs, this study supports further investigation to evaluate long-term performance of the HAV when used to repair traumatic vascular injuries.

An Analysis of Malpractice Litigation of Vascular Surgeons in Cases Involving Aortic Pathologies

OBJECTIVE

The aim of this study was to analyze malpractice claims for aortic pathologies and to assess if there has been a change in rate of malpractice lawsuits with evolution of endovascular therapy.

METHODS

Malpractice lawsuits were individually screened and compiled from the Westlaw database from 2000 to 2017 through use of relevant search terms. Data were collected of allegations, diagnoses, and outcomes of each case and compared.

RESULTS

268 unique cases were included in this study, with aneurysms (54%, n = 145) and dissection (35%, n = 94) making up the majority. There was a defendant verdict in 53% (n = 141), plaintiff verdict in 24% (n = 65), and settlements in 23% (n = 62) of lawsuits. Litigation was higher in the Midwest and Northeast. There was a gradual decline in litigation overall, however endovascular case numbers remained constant. There was negligible difference in the primary allegation underlying the litigation for various aortic pathologies, time to litigation and award between open and endovascular procedures.

CONCLUSION

The proportion of litigation for clinical negligence in endovascular cases amongst all vascular surgical lawsuits is increasing. As novel methods of endovascular therapy emerge, it is imperative that physicians remain vigilant to legal considerations to minimize malpractice risk.

An Implantable Bioprosthetic Venous Valve to Establish Deep Vein Competence for Post-Thrombotic Syndrome

This article discusses the VenoValve bioprosthetic device, which is designed to improve valvular competence in the deep venous system of the lower extremities and treat deep venous insufficiency.

Midterm Clinical Outcomes of Retrograde Open Mesenteric Stenting for Mesenteric Ischemia

BACKGROUND

Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia; however, follow-up in contemporary studies is limited.

METHODS

A single-center retrospective review of patients undergoing ROMS from 2007 to 2020 was conducted. Demographics, presentation, and procedural details were reviewed. End points were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence.

RESULTS

ROMS was performed in 34 patients, 19 female (56%). Mean age was 71 ± 10 years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), 11 (32%) with acute-on-chronic, and 5 (15%) with chronic mesenteric ischemia. Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), superior mesenteric artery dissection in 3, and 1 each with embolic, vasculitic, and nonocclusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 superior mesenteric artery stent) and 1 had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through a retrograde approach was attained in 31 patients (91%), with the 3 remaining patients treated with transbrachial stenting in 2 and iliomesenteric bypass in 1. Covered stents were used in 21 patients (64%) with or without stent extension with bare-metal stents. Eight patients (23%) required thromboembolectomy and 9 (26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or acute-on-chronic (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions within the first 30 days were required in 5 patients (15%), including 2 redo ROMS with thrombectomy and endarterectomy, 2 percutaneous stent extensions, and 1 aortic septum fenestration with coiling of a jejunal branch pseudoaneurysm. With a median follow-up of 3.7 (interquartile range: 0.8-5.0) years, in patients surviving discharge, 5 required reintervention yielding freedom from reintervention rates of 87% at 1 year and 71% at 3 years. All postdischarge reinterventions were endovascular with no conversion to bypass. The overall 1-year and 3-year primary patency rates were 70% and 61% (primary-assisted patency at 1 and 3 years was 87% and secondary patency at 1 and 3 years was 97%). The freedom from symptom recurrence was 95% at 1 and 3 years.

CONCLUSIONS

ROMS carries high rates of technical success in patients with mesenteric ischemia, despite a high chronic atherosclerotic burden. Although mid-term patency rates are acceptable, AMI is still associated with high early morbidity and mortality, with high rates of associated bowel resection. ROMS is a valuable tool in the armamentarium of vascular surgeons.

Clinical presentation, operative management, and long-term outcomes of rupture after previous abdominal aortic aneurysm repair

OBJECTIVE

The aim of the present study was to evaluate the presentation trends, intervention, and survival of patients who had been treated for late abdominal aortic aneurysm rupture (LAR) after open repair (OR) or endovascular aortic aneurysm repair (EVAR).

METHODS

We reviewed the clinical data from a single-center, retrospective database for patients treated for LAR from 2000 to 2020. The end points were the 30-day mortality, major postoperative complication, and survival. The outcomes between LAR managed with EVAR (group I) vs OR were compared (group II).

RESULTS

Of 390 patients with infrarenal aortic rupture, 40 (10%) had experienced aortic rupture after prior aortic repair and comprised the LAR cohort (34 men; age 78 ± 8 years). LAR had occurred before EVAR in 30 and before OR in 10 patients. LAR was more common in the second half of the study with 32 patients after 2010. LAR after prior OR was secondary to ruptured para-anastomotic pseudoaneurysms. After initial EVAR, LAR had occurred despite reintervention in 17 patients (42%). The time to LAR was shorter after prior EVAR than after OR (6 ± 4 vs 12 ± 4 years, respectively; P = .003). Treatment for LAR was EVAR for 25 patients (63%; group I) and OR for 15 (37%, group II). LAR after initial OR was managed with endovascular salvage for 8 of 10 patients. Endovascular management was more frequent in the latter half of the study period. In group I, fenestrated repair had been used for seven patients (28%). Salvage for the remaining cases was feasible with EVAR, aortic cuffs, or limb extensions. The incidence of free rupture, time to treatment, 30-day mortality (8% vs 13%; P = .3), complications (32% vs 60%; P = .1), and disposition were similar between the two groups. Those in group I had had less blood loss (660 vs 3000 mL; P < .001) and less need for dialysis (0% vs 33%; P < .001) than those in group II. The median follow-up was 21 months (interquartile range, 6-45 months). The overall 1-, 3-, and 5-year survival was 76%, 52%, and 41%, respectively, and was similar between groups (28 vs 22 months; P = .48). Late mortality was not related to the aorta.

CONCLUSIONS

LAR after abdominal aortic aneurysm repair has been encountered more frequently in clinical practice, likely driven by the frequency of EVAR. However, most LARs, including those after previous OR, can now be salvaged with endovascular techniques with lower morbidity and mortality.

Lower Extremity Extracorporeal Distal Revascularization in a Swine Model of Prolonged Extremity Ischemia

BACKGROUND

Acute arterial occlusion of the lower extremity is a time-dependent emergency that requires prompt revascularization. Lower extremity extracorporeal distal revascularization (LEEDR) is a technique that can be initiated bedside when definitive therapy is delayed. The aim of this study is to evaluate this technique in a swine model of prolonged extremity ischemia.

METHODS

Anesthetized swine underwent right femoral and left posterior tibial artery cannulation, left iliac venous flow monitoring (mL/min), and continuous left anterior compartment pressure (CP) monitoring (mm Hg). The iliac artery was clamped for 6 hr. LEEDR animals underwent 5 hr of extracorporeal femoral-to-tibial blood flow at 150 mL/min; controls had no intervention. At 6 hr, LEEDR was discontinued, iliac flow restored, and anterior CP monitored for 3 hr.

RESULTS

Baseline characteristics were similar across both the groups. Iliac clamping saw an expected fall in iliac venous flow (258 ± 30 to 82 ± 19; P < 0.001). LEEDR resulted in a rise in iliac venous flow (82 ± 20 to 181 ± 16; P < 0.001); control arm flow remained reduced (71 ± 8; P < 0.001). Once inflow was restored, venous flow returned to baseline. Revascularization provoked a higher peak CP in the control arm versus in the LEEDR group (25 ± 5 vs. 6 ± 1; P = 0.02).

CONCLUSIONS

An extracorporeal circuit can temporarily revascularize an extremity in a swine model of prolonged ischemia, mitigating reperfusion injury and maintaining normal CPs. This concept should undergo further evaluation as a bedside tool to mitigate extremity ischemia prior to definitive revascularization.

Next-Generation REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta) Device Precisely Achieves Targeted Regional Optimization in a Porcine Model of Hemorrhagic Shock

INTRODUCTION

Limitations such as time-dependent distal ischemia have slowed the adoption of resuscitative endovascular balloon occlusion of the aorta (REBOA) for noncompressible hemorrhage. Next-generation REBOA technologies may allow for controlled partial flow, known as targeted regional optimization, to reduce distal ischemia. We aimed to characterize the efficacy of one such catheter in a porcine model of lethal hemorrhagic shock.

METHODS

Noncompressible hemorrhage from an iliac injury was induced in anesthetized swine (Sus scrofa) (70-90 kg), targeting 30% total blood volume. Animals were then randomized to partial aortic occlusion (PO) with targeted distal mean arterial pressure (MAP) of 35-40 mm of mercury (mm Hg) and complete aortic occlusion (CO) (n = 8 per group) for 90 min. All groups were then resuscitated during a two-h critical care (CC) phase, with flow rate and MAP recorded continuously at the distal infrarenal aorta and proximal carotid artery, and analyzed with two-way repeated measures analysis of variance with S-N-K post-hoc test.

RESULTS

During aortic occlusion, MAP distal to the balloon was consistently maintained at 35.8 ± 0.3 mm Hg in the PO group compared to 27.1 ± 0.3 mm Hg in the CO group (P < 0.05), which also corresponded to higher flow rates (202.9 ± 4.8 mL/min PO versus 25.9 ± 0.8 mL/min CO; P < 0.05). MAP proximal to the balloon was significantly higher with CO versus PO (109.2 ± 2.3 mm Hg versus 85.2 ± 2.3 mm Hg; P < 0.05). During the CC phase, distal aortic flow and MAP were not significantly different between groups. However, creatinine returned to baseline levels by the end of the study in the PO group, but not the CO group. One animal died in the CO group, whereas none died in the PO group.

CONCLUSIONS

This is the first examination of the next-generation pREBOA-PRO in a porcine model of lethal hemorrhagic shock. We show technical feasibility of this technique to precisely achieve targeted regional optimization without device failure or complication. The ability to titrate balloon inflation and thus distal flow/pressure may extend the therapeutic window of REBOA by mitigating distal ischemia.

Impact of Ischemia Duration on Lower Limb Salvage in Combat Casualties

INTRODUCTION

The 6-hour threshold to revascularization of an ischemic limb is ubiquitous in the trauma literature, however, contemporary evidence suggests that this threshold should be less. This study aims to characterize the relationship between the duration of limb ischemia and successful limb salvage following lower extremity arterial trauma.

METHODS

This is a cohort study of the United States and UK military service members injured while serving in Iraq or Afghanistan between 2003 and 2013. Consecutive patients who sustained iliac, femoral, or popliteal artery injuries, and underwent surgery to attempt revascularization, were included. The association between limb outcome and the duration of limb ischemia was assessed using the Kaplan-Meier method.

RESULTS

One hundred twenty-two patients (129 limbs) who sustained iliac (2.3%), femoral (56.6%), and popliteal (41.1%) arterial injuries were included. Overall, 87 limbs (67.4%) were successfully salvaged. The probability of limb salvage was 86.0% when ischemia was ≤1 hour; 68.3% when between 1 and 3 hours; 56.3% when between 3 and 6 hours; and 6.7% when >6 hours ( P <0.0001). Shock more than doubled the risk of failed limb salvage [hazard ratio=2.42 (95% confidence interval: 1.27-4.62)].

CONCLUSIONS

Limb salvage is critically dependent on the duration of ischemia with a 10% reduction in the probability of successful limb salvage for every hour delay to revascularization. The presence of shock significantly worsens this relationship. Military trauma systems should prioritize rapid hemorrhage control and early limb revascularization within 1 hour of injury.

Whole Blood Selective Aortic Arch Perfusion for Exsanguination Cardiac Arrest: Assessing Myocardial Tolerance to the Duration of Cardiac Arrest

INTRODUCTION

Selective aortic arch perfusion (SAAP) is an endovascular technique that consists of aortic occlusion with perfusion of the coronary and cerebral circulation. It been shown to facilitate return of spontaneous circulation (ROSC) after exanguination cardiac arrest (ECA), but it is not known how long arrest may last before the myocardium can no longer be durably recovered. The aim of this study is to assess the myocardial tolerance to exsanguination cardiac arrest before successful ROSC with SAAP.

METHODS

Male adult swine (n = 24) were anesthetized, instrumented, and hemorrhaged to arrest. Animals were randomized into three groups: 5, 10, and 15 min of cardiac arrest before resuscitation with SAAP. Following ROSC, animals were observed for 60 min in a critical care environment. Primary outcomes were ROSC, and survival at 1-h post-ROSC.

RESULTS

Shorter cardiac arrest time was associated with higher ROSC rate and better 1-h survival. ROSC was obtained for 100% (8/8) of the 5-min ECA group, 75% (6/8) of the 10-min group, 43% (3/7) of the 15-min group (P = 0.04). One-hour post-ROSC survival was 75%, 50%, and 14% in 5-, 10-, and 15-min groups, respectively (P = 0.02). One-hour survivors in the 5-min group required less norepinephrine (1.31 mg ± 0.83 mg) compared with 10-SAAP (0.76 mg ± 0.24 mg), P = 0.008.

CONCLUSION

Whole blood SAAP can accomplish ROSC at high rates even after 10 min of unsupported cardiac arrest secondary to hemorrhage, with some viability beyond to 15 min. This is promising as a tool for ECA, but requires additional optimization and clinical trials.Animal Use Protocol, IACUC: 0919015.

The functional vascular anatomy of the swine for research

OBJECTIVES

Swine (Sus Scrofa) are utilized broadly in research settings, given similarities to human vessel size and function; however, there are some important differences for clinicians to understand in order to interpret and perform translational research. This review article uses angiograms acquired in the course of a translational research program to present a description of the functional anatomy of the swine.

METHODS

Digital subtraction angiography and computed tomography angiography were obtained throughout the course of multiple studies utilizing power injection with iodinated contrast. Subtracted two-dimensional images and three-dimensional multiplanar reformations were utilized post image acquisition to create maximal intensity projections and three-dimensional renderings of using open-source software (OsiriX). These imaging data are presented along with vessel measurements for reference.

RESULTS

An atlas highlighting swine vascular anatomy, with an emphasis on inter-species differences that may influence how studies are conducted and interpreted, was compiled.

CONCLUSIONS

Swine are utilized in broad-reaching fields for preclinical research. While many similarities between human and swine vasculature exist, there are important differences to consider when conducting and interpreting research. This review article highlights these differences and presents accompanying images to inform clinicians gaining experience in swine research.

Open chest selective aortic arch perfusion vs open cardiac massage as a means of perfusion during in exsanguination cardiac arrest: a comparison of coronary hemodynamics in swine

AIM

To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine.

METHODS

Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5 min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1 min of OCSAAP at a rate of 10 mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared.

RESULTS

At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP > 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP.

CONCLUSION

OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT).

Selective Prehospital Advanced Resuscitative Care - Developing a Strategy to Prevent Prehospital Deaths From Noncompressible Torso Hemorrhage

Hemorrhage, and particularly noncompressible torso hemorrhage remains a leading cause of potentially preventable prehospital death from trauma in the United States and globally. A subset of severely injured patients either die in the field or develop irreversible hemorrhagic shock before they can receive hospital definitive care, resulting in poor outcomes. The focus of this opinion paper is to delineate (a) the need for existing trauma systems to adapt so that potentially life-saving advanced resuscitation and truncal hemorrhage control interventions can be delivered closer to the point-of-injury in select patients, and (b) a possible mechanism through which some trauma systems can train and incorporate select prehospital advanced resuscitative care teams to deliver those interventions.

Bioengineered Acellular Vessel Implantation in a Patient with Chronic Limb-Threatening Ischemia: A Case Report and Discussion of Implications for Trauma

The ideal conduit for vascular reconstruction is one that can be obtained “off the shelf” and demonstrates long-term patency, tissue incorporation and resistance to infection. Currently available conduits, such as autologous vein and synthetic grafts, are limited in one or more of these areas. The Human Acellular Vessel (HAV), a bioengineered, acellular blood vessel, can be obtained “off the shelf” and has shown promise in each of these properties. We describe a case in which the HAV was utilized for open bypass reconstruction in a patient with chronic limb-threatening ischemia who lacked alternative reconstructive options. The case is followed by a discussion of potential broader applications of this novel implant, specifically in the management of vascular trauma.  

Targeted Regional Optimization: Increasing the Therapeutic Window for Endovascular Aortic Occlusion In Traumatic Hemorrhage

ABSTRACT

Resuscitative endovascular balloon occlusion of the aorta (REBOA) allows for effective temporization of exsanguination from non-compressible hemorrhage (NCTH) below the diaphragm. However, the therapeutic window for aortic occlusion is time-limited given the ischemia-reperfusion injury generated. Significant effort has been put into translational research to develop new strategies to alleviate the ischemia-reperfusion injury and extend the application of endoaortic occlusion. Targeted regional optimization (TRO) is a partial REBOA strategy to augment proximal aortic and cerebral blood flow while targeting minimal threshold of distal perfusion beyond the zone of partial aortic occlusion. The objective of TRO is to reduce the degree of ischemia caused by complete aortic occlusion while providing control of distal hemorrhage. This review provides a synopsis of the concept of TRO, pre-clinical, translational experiences with TRO and early clinical outcomes. Early results from TRO strategies are promising; however, further studies are needed prior to large-scale implementation into clinical practice.

Developing a tool to assess competence in resuscitative endovascular balloon occlusion of the aorta: An international Delphi consensus study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emergency procedure that is potentially lifesaving in major noncompressible torso hemorrhage. It may also improve outcome in nontraumatic cardiac arrest. However, the procedure can be technically challenging and requires the immediate presence of a qualified operator. Thus, evidence-based training and assessment of operator skills are essential for successful implementation and patient safety. A prerequisite for this is a valid and reliable assessment tool specific for the procedure. The aim of this study was to develop a tool for assessing procedural competence in REBOA based on best-available knowledge from international experts in the field.

METHODS

We invited international REBOA experts from multiple specialties to participate in an anonymous three-round iterative Delphi study to reach consensus on the design and content of an assessment tool. In round 1, participants suggested items to be included. In rounds 2 and 3, the relevance of each suggested item was evaluated by all participants to reach consensus. Interround data processing was done systematically by a steering group.

RESULTS

Forty panelists representing both clinical and educational expertise in REBOA from 16 countries (in Europe, Asia, and North and South America) and seven different specialties participated in the study. After 3 Delphi rounds and 532 initial item suggestions, the panelists reached consensus on a 10-item assessment tool with behaviorally anchored rating scales. It includes assessment of teamwork, procedure time, selection and preparation of equipment, puncture technique, guidewire handling, sheath handling, placement of REBOA catheter, occlusion, and evaluation.

CONCLUSION

We present the REBOA-RATE assessment tool developed systematically by international experts in the field to optimize content validity. Following further studies of its validity and reliability, this tool represents an important next step in evidence-based training programs in REBOA, for example, using mastery learning.

LEVEL OF EVIDENCE

Therapeutic, level V.

A multi-registry analysis of military and civilian penetrating cervical carotid artery injury

INTRODUCTION

Penetrating cervical carotid artery injury is an uncommon but high-stake scenario associated with stroke and death. The objective of this study was to characterize and compare penetrating carotid injury in the military and civilian setting, as well as provide considerations for management.

METHODS

Cohorts with penetrating cervical carotid artery injury from the Department of Defense Trauma Registry (2002-2015) and the American Association for the Surgery of Trauma Prospective Observation Vascular Injury Treatment Registry (2012-2018) were analyzed. A least absolute shrinkage and selection operator multivariate analysis using random forest-based imputation was performed to identify risk factors affecting stroke and mortality.

RESULTS

There were a total of 157 patients included in the study, of which 56 (35.7%) were military and 101 (64.3%) were civilian. The military cohort was more likely to have been managed with open surgery (87.5% vs. 44.6%, p < 0.001) and to have had any procedure to restore or maintain flow to the brain (71.4% vs. 35.6%, p < 0.001), while the civilian cohort was more likely to undergo nonoperative management (45.5% vs. 12.5%, p < 0.001). Stroke rate was higher within the military cohort (41.1% vs. 13.9%, p < 0.001); however, mortality did not differ between the groups (12.5% vs. 17.8%, p = 0.52). On multivariate analysis, predictors for stroke were presence of a battle injury (log odds, 2.1; p < 0.001) and internal or common carotid artery ligation (log odds 1.5, p = 0.009). For mortality outcome, protective factors included a high Glasgow Coma Scale on admission (log odds, -0.21 per point; p < 0.001). Increased admission Injury Severity Score was a predictor of mortality (log odds, 0.05 per point; p = 0.005).

CONCLUSION

The stroke rate was higher in the military cohort, possibly reflecting complexity of injury; however, there was no difference in mortality between military and civilian patients. For significant injuries, concerted efforts should be made at carotid reconstruction to reduce the occurrence of stroke.

LEVEL OF EVIDENCE

Retrospective cohort analysis, level III.

O10 Myocardial tolerance to exsanguination and retrieval using whole blood-selective aortic arch perfusion

Introduction

Exsanguination cardiac arrest is the leading preventable cause of death in trauma. Treatment modalities are limited, and prognosis remains dismal. Selective aortic arch perfusion (SAAP) is an emerging endovascular resuscitation technique consisting of aortic occlusion and perfusion of coronary and cerebral circulation with oxygenated resuscitation fluid. Translational research has demonstrated promising outcomes; however, little is known about the duration of cardiac arrest beyond which the myocardium cannot be resuscitated. The aims of this study are to assess the myocardial tolerance to exsanguination cardiac arrest before successful return of spontaneous circulation (ROSC) following resuscitation with SAAP, and 1-hour survival.

Method

23 male adult swine were anaesthetised and instrumented. Controlled hemorrhage was performed until cardiac arrest defined by MAP &lt;20 mmHg. Animals were randomized into 3 groups: 5, 10 and 15 minutes of cardiac arrest before resuscitation with SAAP. Following ROSC animals were observed for 60 minutes.

Result

Baseline characteristics were similar between groups (P &gt; 0.05). ROSC was 100% (8/8) in the 5 min group, 75% (6/8) and 43% (3/7) in 10- and 15-min groups respectively (P = 0.042). 60 min survival was 75%, 50% and 14% in 5-, 10- and 15-min groups respectively (P = 0.015). 1-hour survivors in the 5 min group required less noradrenaline 23.6 (±7.4) compared to other animals 40.9 (±25.8), (P = 0.008).

Conclusion

Selective aortic arch perfusion is an effective resuscitative tool in eliciting ROSC in a swine model of exsanguination cardiac arrest lasting &gt;5 min. Sustainable resuscitability using SAAP declines after 10 min of exsanguination cardiac arrest.

Take-home Message

SAAP is an emerging resuscitation technique with promising outcomes in exsanguination cardiac arrest and may be a segway to Extracorporeal life support. The time limit for resuscitability of the myocardium lies somewhere between 10 and 15 min after the start of exsanguination cardiac arrest.

Blunt cerebrovascular injuries: Outcomes from the American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment (PROOVIT) multicenter registry

BACKGROUND

Administering antithrombotics (AT) to the multiply injured patient with blunt cerebrovascular injury (BCVI) requires a thoughtful assessment of the risk of stroke and death associated with nontreatment. Large, multicenter analysis of outcomes stratified by injury grade and vessel injured is needed to inform future recommendations.

METHODS

Nine hundred and seventy-one BCVIs were identified from the PROspective Vascular Injury Treatment registry in this retrospective analysis. Using multivariate analysis, we identified predictors of BCVI-related stroke and death. We then stratified these risks by injury grade and vessel injured. We compared the risk of adverse outcomes in the nontreatment group with those treated with antiplatelet agents and/or anticoagulants.

RESULTS

Stroke was identified in 7% of cases. Overall mortality was 12%. Both increased with increasing BCVI grade. Treatment with ATs was associated with lower mortality and was not significantly affected by the choice of agent. Withholding ATs was associated with an increased risk of stroke and/or death across all subgroups (Grade I/II: odds ratio [OR], 4.66; 95% confidence interval [CI], 2.48-8.75; Grade III: OR, 7.0; 95% CI, 2.01-24.5; Grade IV: OR, 4.43; 95% CI, 1.76-11.1) even after controlling for covariates. Predictors of death included more severe trauma, Grade IV injury, and the occurrence of stroke. Arterial occlusion, hypotension, and endovascular intervention were significant predictors of stroke. Patients that experienced a BCVI-related stroke were at a 4.2× increased risk of death. The data set lacked the granularity necessary to evaluate AT timing or dosing regimen, which limited further analysis of stroke prevention strategies.

CONCLUSION

Stroke and death remain significant risks for all BCVI grades regardless of the vessel injured. Antithrombotics represent the only management strategy that is consistently associated with a lower incidence of stroke and death in all BCVI categories. In the multi-injured BCVI patient with a high risk of bleeding on anticoagulation, antiplatelet agents are an efficacious alternative. Given the 40% mortality rate in patients who survived their initial trauma and developed a BCVI-related stroke, nontreatment may no longer be a viable option.

LEVEL OF EVIDENCE

Epidemiological III; Therapeutic IV.

Measuring Cardiac Output in a Swine Model

Swine are frequently used in medical research given their similar cardiac physiology to that of humans. Measuring cardiac parameters such as stroke volume and cardiac output are essential in this type of research. Contrast ventriculography, thermodilution, and pressure-volume loop (PV-loop) catheters can be used to accurately obtain cardiac performance data depending on which resources and expertise are available. For this study,five Yorkshire swine were anesthetized and intubated. Central venous and arterial access was obtained to place the necessary measurement instruments.A temperature probe was placed in the aortic root. A cold saline bolus was delivered to the right atrium and temperature deflection curve was recorded. Integration of the area under the curve allowed for the calculation of the current cardiac output.A pigtail catheter was percutaneously placed in the left ventricle and 30 mL of iodinated contrast was power injected over 2 seconds. Digital subtraction angiography images were uploaded to volumetric analysis software to calculate the stroke volume and cardiac output. A pressure volume-loop catheter was placed into the left ventricle (LV) and provided continuous pressure and volume data of the LV, which allowed the calculation of both stroke volume and cardiac output.All three methods demonstrated good correlation with each other. The PV-loop catheter and thermodilution exhibited the best correlation with a 3% error and a Pearson coefficient of 0.99, with 95% CI=0.97 to 1.1, (p=0.002). The PV-loop catheter against ventriculography also showed good correlation with a 6% error and a Pearson coefficient of 0.95, 95% CI=0.96 to 1.1 (p=0.01). Finally, thermodilution against ventriculography had a 2% error with r=0.95, 95% CI=0.93 to 1.11, (p=0.01). In conclusion, we state that the PV-loop catheter, contrast ventriculography, and thermodilution each offer certain advantages depending on the researcher's requirements. Each method is reliable and accurate for measuring various cardiac parameters in swine such as the stroke volume and cardiac output.

Selective aortic arch perfusion versus open cardiac massage in exsanguination cardiac arrest: A comparison of coronary pressure dynamics in swine

AIM

To evaluate the mean aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) observed during open cardiac massage (OCM) versus those obtained with selective aortic arch perfusion (SAAP) in post-mortem hypovolemic swine.

METHODS

Post-mortum, male swine, utilized in prior studies of hemorrhage, were included in the study. Animals were bled ∼25-50% of circulating volume prior to death. Animals either underwent clamshell thoracotomy and OCM immediately after death was confirmed (n = 6) or underwent SAAP within 5-15 min of death (n = 6). Aortic root and right atrial pressures were recorded continuously during each method of resuscitation using solid state blood pressure catheters. Representative five beat samples were extracted; short, similarly timed segments of SAAP were also extracted. Mean AoP-RAP gradient and CPPs were calculated and compared.

RESULTS

Mean AoP-RAP gradient and CPP were significantly higher in SAAP animals compared to OCM animals (mean ± SD; 29.1 ± 8.4 vs. 24.5 ± 5.0, p < 0.001; 28.9 ± 8.5 vs. 9.9 ± 6.0, p < 0.001). Mean CPP was not significantly different from mean AoP-RAP gradient in SAAP animals (p = 0.92); mean CPP was significantly lower than mean AoP-RAP gradient in OCM animals (p < 0.001). While 97% of SAAP segments had a CPP > 15 mmHg, only 17% of OCM segments had a CPP > 15 mmHg (p < 0.001).

CONCLUSION

SAAP appears to create a more favorable and efficient hemodynamic profile for obtaining ROSC when compared to OCM in this preclinical porcine study.

The polytrauma patient: Current concepts and evolving care

Principles of care in the polytraumatized patient have continued to evolve with advancements in technology. Although hemorrhage has remained a primary cause of morbidity and mortality in acute trauma, emerging strategies that can be applied pre-medical facility as well as in-hospital have continued to improve care. Exo-vascular modalities, including the use of devices to address torso hemorrhage and areas not amenable to traditional tourniquets, have revolutionized prehospital treatment. Endovascular advancements including the resuscitative endovascular balloon occlusion of the aorta (REBOA), have led to dramatic improvements in systolic blood pressure, although not without their own unique complications. Although novel treatment options have continued to emerge, so too have concepts regarding optimal time frames for intervention. Though prior care has focused on Injury Severity Score (ISS) as a marker to determine timing of intervention, current consensus contends that unnecessary delays in fracture care should be avoided, while respecting the complex physiology of certain patient groups that may remain at increased risk for complications. Thromboelastography (TEG) has been one technique that focuses on the unique pathophysiology of each patient, providing guidance for resuscitation in addition to providing information in recognizing the at-risk patient for venous thromboembolism. Negative pressure wound therapy (NPWT) has emerged as a therapeutic adjuvant for select trauma patients with significant soft tissue defects and open wounds. With significant advancements in medical technology and improved understanding of patient physiology, the optimal approach to the polytrauma patient continues to evolve.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): update and insights into current practices and future directions for research and implementation

Background

In this review, we assess the state of Resuscitative Endovascular Occlusion of the Aorta (REBOA) today with respect to out-of-hospital (OOH) vs. inhospital (H) use in blunt and penetrating trauma, as well as discuss areas of promising research that may be key in further advancement of REBOA applications.

Methods

To analyze the trends in REBOA use, we conducted a review of the literature and identified articles with human or animal data that fit the respective inclusion and exclusion criteria. In separate tables, we compiled data extracted from selected articles in categories including injury type, zone and duration of REBOA, setting in which REBOA was performed, sample size, age, sex and outcome. Based on these tables as well as more detailed review of some key cases of REBOA usage, we assessed the current state of REBOA as well as coagulation and histological disturbances associated with its usage. All statistical tests were 2-sided using an alpha=0.05 for significance. Analysis was done using SAS 9.5 (Cary, NC). Tests for significance was done with a t-test for continuous data and a Chi Square Test for categorical data.

Results

In a total of 44 cases performed outside of a hospital in both military and civilian settings, the overall survival was found to be 88.6%, significantly higher than the 50.4% survival calculated from 1,807 cases of REBOA performed within a hospital (p<.0001). We observe from human data a propensity to use Zone I in penetrating trauma and Zone III in blunt injuries. We observe lower final metabolic markers in animal studies with shorter REBOA time and longer follow-up times.

Conclusions

Further research related to human use of REBOA must be focused on earlier initiation of REBOA after injury which may depend on development of rapid vascular access devices and techniques more so than on any new improvements in REBOA. Future animal studies should provide detailed multisystem organ assessment to accurately define organ injury and metabolic burden associated with REBOA application. Overall, animal studies must involve realistic models of injury with severe clinical scenarios approximating human trauma and exsanguination, especially with long-term follow-up after injury.

Potentially survivable fatal vascular access hemorrhage with tourniquet use: A post-mortem analysis

BACKGROUND

The US military has prioritized battlefield hemorrhage control. Researchers credit tourniquet use, and a novel trauma care training program, with saving 1000-2000 lives in Iraq and Afghanistan. The Stop the Bleed campaign translates these lessons learned to the public. This is the first analysis of the potential impact of this newfound knowledge about tourniquet use for extremity fatal vascular access hemorrhage in a civilian population. Fatal vascular access hemorrhage includes bleeding from arteriovenous fistulas and grafts used for hemodialysis and central venous catheters.

METHODS

This is a retrospective study of decedent records. We selected Maryland death records from 2002-2017 using the following search terms: "graft," "shunt," "fistula," "dialysis," and "central venous catheter." The records were analyzed for potential survivability with a checklist of military criteria modified for a civilian population. Suicides were excluded. Two reviewers independently classified the deaths as either potentially survivable or non-survivable, and a third reviewer broke ties.

RESULTS

There were 111 deaths included in the final analysis. Ninety-two of the 111 decedents had potentially survivable extremity fatal vascular access hemorrhage. The remaining 19 records were excluded, because they did not have extremity hemorrhage. Zero decedents had hemorrhage deemed to be non-survivable with prompt tourniquet application.

CONCLUSION

This study identified 92 Maryland extremity fatal vascular access hemorrhage decedents who potentially could have survived with tourniquet use-an average of 6 per year. These results suggest the need for further epidemiology investigation, as well as exploration of the risks and benefits of teaching and equipping vascular access patients and their caregivers to use tourniquets for life-threatening bleeding.