Technical and analytical approach to biventricular pressure-volume loops in swine including a completely endovascular, percutaneous closed-chest large animal model.

Pressure-volume (PV) loop analysis is a sophisticated invasive approach to quantifying load-dependent and independent measures of cardiac function. Biventricular (BV) PV loops allow left and right ventricular function to be quantified simultaneously and independently, which is important for conditions and certain physiologic states, such as ventricular decoupling or acute physiologic changes. BV PV loops can be performed in an entirely endovascular, percutaneous, and closed-chest setting. This technique is helpful in a survival animal model, as a percutaneous monitoring system during endovascular device experiments, or in cases where chest wall compliance is being tested or may be a confounder. In this article, we describe the end-to-end implementation of a completely endovascular, totally percutaneous, and closed-chest large animal model to obtain contemporaneous BV PV loops in 40 to 70 kg swine. We describe the associated surgical and technical challenges and our solutions to obtaining endovascular BV PV loops, closed-chest cardiac output, and stroke volume (including validation of the correction factor necessary for thermodilution), as well as how to perform endovascular inferior vena cava occlusion in this swine model. We also include techniques for data acquisition and analysis that are required for this method.

Outcomes Associated With Aortic Balloon Occlusion Time in Patients With Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to cause clinically relevant systemic ischemic burden with long durations of aortic occlusion (AO). We aimed to examine the association between balloon occlusion time and clinical complications and mortality outcomes in patients undergoing zone 1 REBOA. METHODS: A retrospective cohort analysis of American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acuteregistry patients with Zone 1 REBOA between 2013 and 2022 was performed. Patients with cardiopulmonary resuscitation on arrival or who did not survive past the emergency department were excluded. Total AO times were categorized as follows: <15 min, 15-30 min, 31-60 min, and >60 min. Clinical and procedural variables and in-hospital outcomes were compared across groups using bivariate and multivariate regression analyses. RESULTS: There were 327 cases meeting inclusion criteria (n = 51 < 15 min, 83 15-30 min, 98 31-60 min, and 95 > 60 min, respectively). AO >60 min had higher admission lactate (8 ± 6; P = 0.004) compared to all other time groups, but injury severity score, heart rate, and systolic blood pressure were similar. Group average times from admission to definitive hemorrhage control ranged from 82 to 103 min and were similar across groups (85 min in AO >60 group). Longer AO times were associated with greater red blood cell, fresh frozen plasma transfusions (P < 0.001), and vasopressor use (P = 0.001). Mortality was greatest in the >60 min group (73%) versus the <15 min, 15-30 min, and 31-60 min groups (53%, 43%, and 45%, P < 0.001). With adjustment for injury severity score, systolic blood pressure, and lactate, AO >60 min had greater mortality (OR 3.7, 95% CI 1.6-9.4; P < 0.001) than other AO duration groups. Among 153 survivors, AO >60 min had a higher rate of multiple organ failure (15.4%) compared to the other AO durations (0%, 0%, and 4%, P = 0.02). There were no differences in amputation rates (0.7%) or spinal cord ischemia (1.4%). acute kidney injury was seen in 41% of >60 min versus 21%, 27%, and 33%, P = 0.42. CONCLUSIONS: Though greater preocclusion physiologic injury may have been present, REBOA-induced ischemic insult was correlated with poor patient outcomes, specifically, REBOA inflation time >60 min had higher rates of mortality and multiple organ failure. Minimizing AO duration should be prioritized, and AO should not delay achieving definitive hemostasis. Partial REBOA may be a solution to extend safe AO time and deserves further study.

In-Hospital Mortality Risk and Discharge Disposition Following Hip Fractures: An Analysis of the Texas Trauma Registry.

Background: In-hospital mortality and discharge disposition following traumatic hip fractures previously reported in the literature, has mainly focused on a nationwide scale, which may not be reflective of unique populations. Objective: Our aim was to characterize demographics, hospital disposition, and associated outcomes for patients with the most common hip fractures. Methods: A retrospective study utilizing the Trauma Registry from the Texas Department of State Health Services. Patient demographics, injury characteristics, and outcomes, such as in-hospital mortality, and discharge dispositions, were collected. The data were analyzed via univariate analysis and multivariate regressions. Results: There were 17,104 included patients, composed of 45% femoral neck fractures (FN) and 55% intertrochanteric fractures (IT). There were no differences in injury severity score (ISS) (9 ± 1.8) or age (77.4 ± 8 years old) between fracture types. In-hospital mortality risk was low but different among fracture types (intertrochanteric, 1.9% vs femoral neck, 1.3%, P = .004). However, when controlling for age, and ISS, intertrochanteric fractures and Hispanic patients were associated with higher mortality (P < .001, OR 1.5, 95% CI 1.1-2.0). Uninsured, and Black/African American (P = .05, OR 1.2, 95% CI 1.1-1.3) and Hispanic (P < .001, OR 1.2, 95% CI 1.1-1.3) patients were more likely to be discharged home after adjusting for age, ISS, and payment method. Conclusion: Regardless of age, severity of the injury or admission hemodynamics, intertrochanteric fractures and Hispanic/Latino patients had an increased risk of in-hospital mortality. Patients who were uninsured, Hispanic, or Black were discharged home rather than to rehabilitation, regardless of age, ISS, or payment method.

Two Decades of Declining Medicare Reimbursement in Cardiac Surgery.

BACKGROUND: Given the uncertainty of US health care finances, an understanding of reimbursement trends has become increasingly important in the field of cardiac surgery. We aimed to assess Medicare reimbursement trends for common cardiac surgical procedures from 2000 to 2022. METHODS: Reimbursement data were extracted from the Centers for Medicare and Medicaid Services Physician Fee Schedule Look-Up Tool during the study period for 6 common cardiac operations: aortic valve replacement, mitral valve repair and replacement, tricuspid valve replacement, Bentall procedure, and coronary artery bypass grafting. Reimbursement rates were adjusted for inflation to 2022 US dollars using the Consumer Price Index. Total percentage change and compound annual growth rate were calculated. A split-time analysis was performed to assess trends before and after 2015. Least squares and linear regressions were performed. The R2 value was calculated for each procedure, and slope was used to determine change in reimbursements over time. RESULTS: Inflation-adjusted reimbursement decreased by 34.1% during the study period. The overall compound annual growth rate was -1.8%. Reimbursement trends differed by procedure (P < .001), with all reimbursements trending down (R2 > 0.62), except for mitral valve replacement (P = .21) and tricuspid valve replacement (P = .43). Coronary artery bypass grafting decreased the most (-44.4%), followed by aortic valve replacement (-40.1%), mitral valve repair (-38.5%), mitral valve replacement (-29.8%), Bentall procedure (-28.5%), and tricuspid valve replacement (-25.3%). In split-time analysis, reimbursement rates did not significantly change from 2000 to 2015 (P = .24) but decreased significantly from 2016 to 2022 (P = .001). CONCLUSIONS: Medicare reimbursement significantly decreased for most cardiac surgical procedures. These trends justify further advocacy by The Society of Thoracic Surgeons to maintain access to quality cardiac surgical care.

Endovascular stenting techniques for blunt carotid injury.

OBJECTIVES: While methods of endovascular carotid artery stenting have improved over time, concerns surrounding the safety and efficacy of stenting for blunt carotid injury (BCI) remain. This study aims to present our approach to carotid artery stenting (CAS) by incorporating new technologies such as flow-diverting stents and circuits. METHODS: There is no robust evidence to support routine carotid artery stenting; however, there are several therapeutic options and approaches for treating BCI that currently require an individualized approach. Endovascular stenting and specific stent selection are largely dictated by the disease process the surgeon intends to treat. We will discuss patient selection, medical management, and the most common revascularization techniques, including transfemoral stenting, trans-carotid arterial revascularization using flow reversal, and stent-assisting coiling. RESULTS: It must be stressed that endovascular intervention is not an alternative to or preclusive of antithrombotic or anticoagulant therapy. In the setting of BCI, transfemoral CAS is most appropriate in patients who are symptomatic, have a rapidly progressing or large lesion, and do not have a soft thrombus present due to risk of embolism. Unlike transfemoral CAS, TCAR offers an elegant solution for embolic protection when patients have a soft thrombus present. In the case of a large pseudoaneurysm, we perform stent-assisted coiling. CONCLUSIONS: We practice selective endovascular intervention, stenting lesions that are flow-limiting or have large or rapidly expanding pseudoaneurysms, and only in patients for whom anticoagulation and antiplatelet agents are not contraindicated. As technology and investigation progress, the concerns regarding the safety and the role of endovascular intervention in the treatment of BCI will be more clearly defined.

Competitiveness of Obstetrics and Gynecology Residency Programs and Applicants.

OBJECTIVE: To assess the change in competitiveness of obstetrics and gynecology programs over 20 years using a normalized competitive index. METHODS: Obstetrics and gynecology match data were obtained from the National Resident Matching Program (NRMP) for 2003-2022. Applicant metrics (United States Medical Licensing Examination scores, score percentiles, research output and experiences, and work and volunteer experiences) were obtained from the NRMP and the Association of American Medical Colleges (2007-2021). The competitive index was calculated using the number of positions available divided by match rate each year between 2003 and 2022. The normalized competitive index was calculated by dividing the yearly competitive index by the average competitive index over 20 years. Data were analyzed using univariate analysis and linear regressions. RESULTS: When comparing the two decades (2003-2012 vs 2013-2022), applicants (1,539±242 vs 1,902±144; P <.001), positions (1,173±31 vs 1,345±98; P <.001), and number of programs ranked per applicant (13±1.4 vs 15±0.6; P <.001) have increased. While the match rate did not significantly change from 2003 to 2022 (75.5%±9.9% vs 70.5%±1.6%; P =.14), the normalized competitive index increased (R 2 =0.92, P <.001), indicating increased competitiveness. Applicant metrics increased over time, including research output (2.4±0.8 vs 5.0±0.7; P =.002) and work experiences (2.9±0.2 vs 3.6±0.1; P =.002; R 2 =0.98, P< .001). CONCLUSION: Despite an increase in obstetrics and gynecology applicants and applicant metrics, match rates remain unchanged. However, the competitiveness of programs has significantly increased, as demonstrated by the normalized competitive index, applicants per position, and applicant metrics. The normalized competitive index is a useful metric for applicants to determine program or applicant competitiveness, especially when used alongside applicant metrics.

Acute management of mesenteric emergencies: Tailoring the solution to the problem.

Acute mesenteric ischemia (AMI) constitutes a life-threatening problem that can result in death, multiorgan failure, and severe nutritional disability. Although AMI is a rare cause of acute abdominal emergencies, ranging between 1 and 2 individuals per 10,000, the morbidity and mortality rates are high. Arterial embolic etiology composes nearly one-half of AMIs, with a sudden onset of severe abdominal pain considered the most common symptom. Arterial thrombosis is the second most common cause of AMI, which presents similarly to arterial embolic AMI, although often more severe due to anatomic differences. Veno-occlusive causes of AMI are the third most common and are associated with an insidious onset of vague abdominal pain. Each patient is unique, and the treatment plan should be tailored to their individual needs. This may include considering the patient's age, comorbidities, and overall health, as well as their preferences and personal circumstances. A multidisciplinary approach involving specialists from different fields, such as surgeons, interventional radiologists, and intensivists, is recommended for the best possible outcome. Potential challenges in tailoring an optimal treatment plan for AMI may include delayed diagnosis, limited availability of specialized care, or patient factors that make some interventions less feasible. Addressing these challenges requires a proactive and collaborative approach, with regular review and adjustment of the treatment plan as needed to ensure the best possible outcome for each patient.

Arterial Access Complications Following Percutaneous Femoral Access in 24-Hour Resuscitative Endovascular Balloon Occlusion of the Aorta Survivors.

INTRODUCTION: With the use of resuscitative endovascular balloon occlusion of the aorta (REBOA) comes the potential for vascular access site complications (VASCs) and limb ischemic sequelae. We aimed to determine the prevalence of VASC and associated clinical and technical factors. METHODS: A retrospective cohort analysis of 24-h survivors undergoing percutaneous REBOA via the femoral artery in the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute care surgery registry between Oct 2013 and Sep 2021 was performed. The primary outcome was VASC, defined as at least one of the following: hematoma, pseudoaneurysm, arteriovenous fistula, arterial stenosis, or the use of patch angioplasty for arterial closure. Associated clinical and procedural variables were examined. Data were analyzed using Fisher exact test, Mann-Whitney-U tests, and linear regression. RESULTS: There were 34 (7%) cases with VASC among 485 meeting inclusion criteria. Hematoma (40%) was the most common, followed by pseudoaneurysm (26%) and patch angioplasty (21%). No differences in demographics or injury/shock severity were noted between cases with and without VASC. The use of ultrasound (US) was protective (VASC, 35% versus no VASC, 51%; P = 0.05). The VASC rate in US cases was 12/242 (5%) versus 22/240 (9.2%) without US. Arterial sheath size >7 Fr was not associated with VASC. US use increased over time (R2 = 0.94, P < 0.001) with a stable rate of VASC (R2 = 0.78, P = 0.61). VASC were associated with limb ischemia (VASC, 15% versus no VASC, 4%; P = 0.006) and arterial bypass procedures (VASC 3% versus no VASC 0%; P < 0.001) but amputation was uncommon (VASC, 3% versus no VASC, 0.4%; P = 0.07). CONCLUSIONS: Percutaneous femoral REBOA had a 7% VASC rate which was stable over time. VASC are associated with limb ischemia but need for surgical intervention and/or amputation is rare. The use of US-guided access appears to be protective against VASC and is recommended for use in all percutaneous femoral REBOA procedures.

Thoracic Endovascular Aortic RepairAcutely Augments Left Ventricular Biomechanics in An Animal Model: A Mechanism for Postoperative Heart Failure and Hypertension.

BACKGROUND: Thoracic aortic stent grafts are thought to decrease aortic compliance and may contribute to hypertension and heart failure after thoracic endovascular aortic repair (TEVAR). Left ventricular (LV) biomechanics immediately after TEVAR, however, have not been quantified. Pressure-volume (PV) loop analysis provides gold-standard LV functional information. The aim of this study is to use an LV PV loop catheter and analysis to characterize the LV biomechanics before and acutely after TEVAR. METHODS: Anesthetized Yorkshire swine (N = 6) were percutaneously instrumented with an LV PV loop catheter. A 20 mm × 10 cm stent graft was deployed distal to the left subclavian via the femoral artery under fluoroscopy. Cardiac biomechanics were assessed before and after TEVAR. As a sensitivity analysis, inferior vena cava occlusion with PV loop assessment was performed pre and post-TEVAR in 1 animal to obtain preload and afterload-independent end-systolic and end-diastolic PV relationships (ESPVR and EDPVR). RESULTS: All animals underwent successful instrumentation and TEVAR. Post-TEVAR, all 6 animals had higher mean LV ESP (106 vs. 118 mm Hg, P = 0.04), with no change in the EDPVR. inferior vena cava occlusion also moved the ESPVR curve upward and leftward, indicating increased LV work per unit time. There was no augmentation of EDPVR following TEVAR (P > 0.05). Postmortem exams in all animals revealed appropriate stent placement and no technical complications. CONCLUSIONS: TEVAR was associated with an acute increase in LV end-systolic pressure and shift in the ESPVR, indicating increased ventricular work. This data provides potential mechanistic insights into the development of post-TEVAR hypertension and heart failure. Future stent graft innovation should focus on minimizing the changes in cardiac physiology.

How to TEVAR swine for scientific research: Technical, anatomic, and device considerations to translate human TEVAR techniques into the large animal laboratory.

OBJECTIVE: Thoracic Endovascular Aortic Repair (TEVAR) is well established in humans. Despite widespread use, additional research questions related to thoracic aortic stenting and endovascular innovation require large animal models. Translating human TEVAR devices and techniques into animal models, however, is a challenge even for experienced endovascular surgeons looking to develop a large animal TEVAR model.This article describes swine-specific strategies to deploy human TEVAR stent grafts, delineate how to select, size, prepare, and re-use human stents and deployment systems in swine, and how to translate human imaging modalities to large animal TEVAR. METHODS: We describe a selection of related TEVAR models and techniques in Yorkshire swine to support scientific inquiry. This includes an animal husbandry and pre-operative preparation and planning program. All imaged specimens in this paper are castrated male Yorkshire swine in the 60-80 kg range and underwent TEVAR with the Medtronic Navion stent and deployment system. RESULTS: To study human aortic stent grafts in swine, the animals generally must be at least 50 kgs to guarantee a 2 cm internal aortic diameter at the left subclavian, and for the iliac arteries to accommodate the human deployment system. Swine will have longer torsos and shorter iliofemoral segments than a human of the same weight which can make human deployment systems too short to reach the left subclavian from the femoral arteries in larger animals. We provide techniques to overcome this, including open iliac access or upside-down carotid TEVAR, which may be particularly useful if the scientific data would be confounded by iliofemoral access.Unlike humans that present clinically with axial imaging, swine will generally not have preoperative imaging, and many translational research laboratories do not have access to inexpensive preoperative CT, or any intraoperative CT scanning, which we are fortunate to have. We describe, therefore, several strategies for imaging in this setting including TEVAR via C-arm fluoroscopy and with or without in-laboratory CT scanning. Due to the low-resource setting of most large animal laboratories, as compared to a human hybrid room, we also describe several techniques to reduce cost and reuse materials, including the stent grafts, which at the end of non-survival experiments can be recovered during necropsy, cleaned, reinserted into the deployment device and reused on additional animals. CONCLUSIONS: This article describes a collection of related techniques and tips to translate human TEVAR imaging, sizing/selection, deployment, and anatomy to swine research. Using this framework alone, an experienced human vascular or endovascular surgeon may develop a complete aortic stenting animal model with strategies for scientific data acquisition.

Exploring Intra-arterial Contrast Administration for Intraoperative Imaging Using a Swine Model.

Intraoperative computed tomography (CT) imaging with endovascular delivery of intra-arterial (IA) contrast could potentially provide higher attenuation with lower contrast volumes than intravenous (IV) administration. We aimed to compare IA and IV contrast use for organ-specific CT abdominal imaging. Five anesthetized swine had external jugular and brachial artery access with ascending aortic pigtail placement. An IV protocol was 100 mL at 5 mL/sec over 20 sec vs 50 mL of IA contrast at 5 mL/sec over 10 sec. Region-of-interest markers were applied to anatomical regions to measure attenuation (HU) over time. IA and IV contrast protocols achieved adequate aortic opacification (IA, 455 ± 289 vs IV, 450 ± 114 HU). The IA contrast aortic attenuation curve reached peak attenuation compared with IV contrast (IA, 8 vs 23 sec; P < .001). Time to peak attenuation was similar between IA and IV contrast in the portal vein (IA, 38 vs IV, 42 sec, P = .25). IA administration achieved a superior contrast-to-noise ratio (CNR) in less time compared with IV (R2 = .94; P < .001). IA contrast achieved adequate opacification with less bolus broadening and a superior CNR compared with IV contrast while using a smaller contrast volume for directed organ-directed imaging.

An analysis of vascular surgery education publications reveals an educational shortage.

BACKGROUND: As vascular surgery training continues to evolve with the growth of integrated vascular surgery residency (0+5) programs and the consolidation of fellowship programs, optimizing all aspects of the education for vascular surgery trainees, both fellows and 0+5 residents, has become increasingly important. In the present study, we aimed to determine the prevalence, quality, and content of vascular surgery education publications across journals. METHODS: Journal websites (n = 26) and PubMed were queried to identify vascular surgery education publications from 2012 to 2021. The publications were organized into 11 content categories: (1) curriculum, (2) simulation, (3) trainee assessment, (4) program evaluation, (5) wellness/burnout, (6) diversity/inclusion, (7) mentorship/career, (8) case outcomes, (9) perceptions of training, (10) social media, and (11) other. Publication interactivity and quality were measured via PlumX data and Medical Education Research Study Quality Instrument scores. The data were analyzed via univariate analysis and linear regression. RESULTS: A total of 115 vascular surgery education publications (0.2% [interquartile range (IQR), 0.04%-0.5%] of total publications) were identified from the selected journals. The Journal of Vascular Surgery had the highest proportion (0.8%) of vascular surgery education publications, followed by the Journal of Surgical Education (0.7%) and Annals of Vascular Surgery (0.6%). Vascular surgery journals constituted most (79%) of the publications. Of the authors, 15% (IQR, 0%-25%) had a master's or doctorate degree in education. Senior authors were more often identified as male gender (77%), and more first authors (41%) were identified as female gender. An interactivity analysis showed that there were 10.3 citations (IQR, 12), 33.1 captures (IQR, 34), and 8.4 social media interactions (IQR 14) per publication. The educational quality had a median Medical Education Research Study Quality Instrument score of 11 (IQR, 9-12.5), with 49% of publications having a score greater than the median. Publications on training (44% curriculum and 20% simulation) were significantly more frequent than other topics (P < .001), with no change in the publication content over 10 years (P = .29). The volume of vascular surgery education publications did not change during the study period (P = .13) despite the ongoing changes in the educational environment. CONCLUSIONS: Despite the increasing importance placed on vascular surgery education by national vascular societies, publications on vascular surgery education have remained sparse among all journals. Also, the vascular surgery educational content has not changed during the past 10 years, with a primary focus on curriculum and simulation training. Further promotion of vascular surgery educational research is required to increase the quality, volume, and diversity of education publications.

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.

Partial vs Full Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in a Swine Model of Raised Intracranial Pressure and Hemorrhagic Shock.

BACKGROUND: Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is a potential method to mitigate the ischemia observed in full REBOA (fREBOA). However, the effect of pREBOA on cerebral perfusion in the setting of raised intracranial pressure (rICP) is unknown. The aim was to evaluate the effects of no REBOA (nREBOA) vs pREBOA vs fREBOA on cerebral perfusion in a swine model of rICP and hemorrhagic shock. STUDY DESIGN: Anesthetized swine (n = 18) underwent instrumentation. Controlled hemorrhage was performed over 30 minutes. rICP was achieved using an intracranial Fogarty catheter inflated to achieve an ICP of 20 mmHg. Animals underwent intervention for 30 minutes, followed by resuscitation. The primary outcome was cerebral perfusion measured by ICP (millimeters of mercury), cerebral perfusion pressure (CPP; millimeters of mercury), and cerebral blood flow (CBF; milliliters per minute per 100 g) derived from CT perfusion. The secondary outcomes included hemodynamics and lactate (millimoles per liter). RESULTS: The peak ICP of pREBOA animals (22.7 ± 2.5) was significantly lower than nREBOA and fREBOA. pREBOA CPP was significantly higher compared with nREBOA and fREBOA during resuscitation. The pREBOA CBF was greater during intervention and resuscitation compared with nREBOA (p < 0.001). Systolic blood pressure was similar between pREBOA and fREBOA, and coronary perfusion was significantly greater in pREBOA. fREBOA had significantly higher lactate during the intervention (9.3 ± 1.3) and resuscitation (8.9 ± 3.5) compared with nREBOA and pREBOA. CONCLUSION: pREBOA produced greater cerebral perfusion, as demonstrated by more favorable CPP, CBF, and ICP values. fREBOA was associated with metabolic derangement and diminished pressure during resuscitation. pREBOA is superior to fREBOA in a swine model and should be considered over fREBOA for aortic occlusion.

Lower Extremity Staged Revascularization (LESR) as a new innovative concept for lower extremity salvage in acute popliteal artery injuries: a hypothesis.

Popliteal artery injury following knee dislocation is associated with significant morbidity and high amputation rates. The complex and multi-disciplinary input required to manage this injury effectively can take time to arrange, prolonging the time to revascularization. Furthermore, open surgical bypass or interposition graft can be technically challenging in the acute setting, further prolonging ischemic time.Temporary intravascular shunts can be used to temporarily restore flow but require surgical exposure which takes time. Endovascular techniques can decrease the time to revascularization; however, endovascular popliteal stent-grafting is controversial because the biomechanical forces relating to flexion and extension of the knee may increase the risk of stent thrombosis. An ideal operation would result in rapid revascularization, eventually leading to a definitive and durable surgical solution.We hypothesize that a staged approach combing extracorporeal shunting, temporary endovascular covered stent placement, external fixation of bony injury, and definitive open repair provides for a superior approach to popliteal artery injury than current standard of care. We term this approach lower extremity staged revascularization (LESR) and the aim is to minimize the known factors contributing to poor outcomes after traumatic popliteal artery injury.

Characterization of cerebral blood flow during open cardiac massage in swine: Effect of volume status.

Introduction: Patients in cardiac arrest treated with resuscitative thoracotomy and open cardiac massage (OCM) have high rates of mortality with poor neurological outcomes. The aim of this study is to quantitate cerebral perfusion during OCM using computed tomography perfusion (CTP) imaging in a swine model of normo- and hypovolemia. Methods: Anesthetized swine underwent instrumentation with right atrial and aortic pressure catheters. A catheter placed in the ascending aorta was used to administer iodinated contrast and CTP imaging acquired. Cerebral blood flow (CBF; ml/100 g of brain) and time to peak (TTP; s) were measured. Animals were then euthanized by exsanguination (hypovolemic group) or potassium chloride injection (normovolemic group) and subjected to a clamshell thoracotomy, aortic cross clamping, OCM, and repeated CTP. Data pertaining to peak coronary perfusion pressure (pCoPP; mmHg) were collected and % CoPP > 15 mmHg (% CoPP; s) calculated post hoc. Results: Normovolemic animals (n = 5) achieved superior pCoPP compared to the hypovolemic animals (n = 5) pCoPP (39.3 vs. 12.3, p < 0.001) and % CoPP (14.5 ± 1.9 vs. 30.9 ± 6.5, p < 0.001). CTP acquisition was successful and TTP elongated from spontaneous circulation, normovolemia to hypovolemia (5.7 vs. 10.8 vs. 14.8, p = 0.01). CBF during OCM was similar between hypovolemic and normovolemic groups (7.5 ± 8.1 vs. 4.9 ± 6.0, p = 0.73) which was significantly lower than baseline values (51.9 ± 12.1, p < 0.001). Conclusion: OCM in normovolemia generates superior coronary hemodynamics compared to hypovolemia. Despite this, neither generates adequate CBF as measured by CTP, compared to baseline. To improve the rate of neurologically intact survivors, novel resuscitative techniques need to be investigated that specifically target cerebral perfusion as existing techniques are inadequate.

Systematic review of vascular surgery recruitment strategies for medical students and general surgery residents.

OBJECTIVES: Recruitment into the vascular surgery specialty is an imperative as the specialty faces significant demographic changes. Due to the changing dynamics in vascular surgery training pathways, we sought to review current literature on recruitment strategies and their effectiveness with medical students and general surgery residents. METHODS: A systematic search, following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, was performed by searching MEDLINE, EMBASE, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Education Resources Information Center (ERIC) databases for studies on vascular surgery recruitment methods for medical students and general surgery residents from inception of databases to December 31, 2021. Reports in English discussing recruitment strategies were included. Reports lacking recruitment method data and those with insufficient data were excluded. RESULTS: Ten reports met inclusion criteria and studied a total of 688 participants. Seven reports (70%) employed simulation, didactic, or online courses. The remaining 30% of studies included data on mentorship, research, or other interventions. Most of the studies (50%) reported data for medical students (MS1-MS4). Interventions specific to residents or both students and residents comprised the other 50% of studies. Simulation and didactic courses increased interest in vascular surgery by a median of 50% (interquartile range, 38%-64%) for both medical students and residents. Importantly, without reinforcement, interest was seen to decrease over time. CONCLUSIONS: Recruitment interventions are useful in increasing student interest in vascular surgery. Early exposure to simulated vascular surgery procedures and mentorship are cited as common reasons for entering the field. Further studies on recruitment strategies focused on long-term outcomes are required.

How Competitive are Integrated Vascular Surgery Residency Programs? A Ten-Year Comparison Using a Normalized Competitive Index.

BACKGROUND: Integrated vascular surgery residency (VS) programs have increased in popularity and offer an accelerated track compared to the traditional fellowship pathway. We sought to create a simple metric for medical students to better assess the competitiveness of VS training programs compared to general surgery (GS) programs. METHODS: GS and VS programs were compared using the National Resident Matching Program match data from 2012 to 2021. Applicant metrics (board scores, research output and experiences, work experiences, and volunteer experiences) from 2015 to 2019 were obtained using the Association of American Medical Colleges Report on Residents. A competitive index (CI) was created (number of programs ranked per applicant divided by match rate) for each specialty and normalized (NCI) to a value of 1 to improve longitudinal comparisons. NCI and number of programs ranked per applicant were plotted across time and a linear regression was performed to evaluate a 10-year trend. RESULTS: The match rate of both specialties was 52% and was similar for GS and VS programs. CI was higher for VS compared to GS (18.4 ± 3.0 vs. 14.5 ± 0.4; P < 0.001). The number of programs ranked per applicant was higher in VS compared to GS (9.4 vs. 7.7, P < 0.05). The linear regression revealed increasing NCI and number of programs ranked per applicant over time for VS programs compared to GS with all R2 > 0.61 (P < 0.001). CONCLUSIONS: Matching into a VS programs is becoming increasingly competitive. The average CI was approximately 27% higher for VS programs compared to GS programs despite similar match rates. As VS programs continue to evolve, NCI may be a more useful metric for applicants.

Quality Analysis of Online Resources for Patients with Peripheral Artery Disease.

BACKGROUND: The burden of peripheral artery disease is significant for public health but the readily available on-line information on the disease is poorly studied. This study seeks to evaluate the quality and readability of patient resources and identify gaps that appear in the top search results for peripheral artery disease. METHODS: Internet searches were performed for "PAD" and "Peripheral Artery Disease" and "PVD" on three search engines and two metasearch engines. The top 30 websites from each search engine were compiled, screened, and evaluated across four categories of information to assess overall quality: accountability, interactivity, structure, and content. Four indices were used to evaluate readability of the text for the viewer. Statistical analyses was performed using Rstudio with ANOVA. RESULTS: Sixty-three websites met inclusion criteria, of which 25 were open access (34.9%), 30 were from hospital/healthcare organization (48%), 5 were from a governmental agency (8%), 4 were industry sponsored (6%), and 2 were from professional medical societies (3%). Median total quality score was 19 out of 47 (IQR, 15 -30): of the components of this score, accountability was 5 out of 17 (2 -10), interactivity was 2 out of 5 (2.0 -2.0), site structure was 3 out of 4 (2.5 -3.0), and site content was 11 out of 21 (7 -14). Total score varied significantly by organization type (P = 0.007). Open access (30, 17 -34, median, IQR) and governmental agency (30, 29 -31) websites scored the highest while hospital/healthcare organization (16, 14v21) websites scored the lowest. Overall readability was low with a median Flesch-Kincaid Grade Level Score of 10.7 (IQR, 10 -12). Using this index, only one website (1.6%) was written below the recommended 6th grade reading level. CONCLUSION: Freely available online patient education materials for peripheral artery disease are poor, have varying quality, and are largely written at a level higher than that of an average US adult thus depriving the patient from understanding the existing information. We recommend that the vascular surgery community re-examine the current offering and provide improved readable websites to patients to facilitate patient education and shared decision making.