Rasmussen, Todd E.

This Viewpoint describes writing letters of recommendation in the era of artificial intelligence.

Background To evaluate the short-term clinical performance of Symvess (acellular tissue engineered vessel-tyod), formerly known as human acellular vessel, or HAV, compared with autologous vein for the treatment of extremity arterial injury. Methods Subjects treated with acellular tissue engineered vessel (ATEV) from two clinical trials were propensity score-matched on a 1:2 basis to PROspective Observational Vascular Injury Trial (PROOVIT) registry subjects with the same injured artery and treated with autologous vein. Matching characteristics included age, sex, trauma type (penetrating vs blunt), injury severity score, mangled extremity severity score, concomitant fracture, shunt use, and ischemia duration>6 hours. Incidence of outcomes (primary/secondary patency, amputation, conduit infection, reintervention for thrombosis/stenosis, pseudoaneurysm, and death) was assessed by a generalized linear model. Outcomes were assessed at Day 30 (ATEV group) or during initial hospitalization (autologous group). Results ATEV subjects lacking suitable autologous vein (n=67) and PROOVIT subjects treated with autologous vein (n=134) suffered injuries to axillary, brachial, femoral, popliteal, and posterior tibial arteries. Subgroups were clinically similar; Injury Severity Score, Mangled Extremity Severity Score, and duration of follow-up (16 vs 30 days) were higher for the ATEV subgroup. Primary patency for the ATEV versus autologous group was 86.6% versus 91.8%, secondary patency: 91.0% versus 97.7%; amputation: 7.5% versus 8.2%; conduit infection: 1.5% versus 0%; reintervention for thrombosis or stenosis: 6.0% versus 8.2%; and death 4.5% versus 4.5%, respectively. No cases of pseudoaneurysm, true aneurysm, or significant differences between the ATEV and autologous groups for any outcome were observed. Conclusions Short-term outcomes were similar between ATEV subjects without feasible autologous vein, and propensity score-matched autologous vein recipients from the PROOVIT registry. The ATEV may provide effective and safe revascularization in subjects with extremity arterial injury without feasible autologous vein. Level of evidence Level 3, Therapeutic/Care Management

Importance Vascular injuries require urgent repair to minimize loss of limb and life. Standard revascularization relies on autologous vein or synthetic grafts, but alternative options are needed when adequate vein is not feasible and when clinical conditions preclude safe use of synthetic materials. Objective To evaluate the performance of the acellular tissue engineered vessel (ATEV) in the repair of extremity arterial injuries. Design, Setting, and Participants Two open-label, single-arm, nonrandomized clinical trials, including 1 prospective civilian study (CLN-PRO-V005 [V005]) and 1 retrospective observational study in a war zone (CLN-PRO-V017 [V017]), were conducted from September 2018 to January 2024 (follow-up ongoing) at 19 level 1 trauma centers in the US and Israel and 5 frontline hospitals in Ukraine. Patients had vascular injury, no autologous vein available for emergent revascularization, and risk factors for wound infection. Data include the subset of patients with extremity injuries and were analyzed from September 2023 to January 2024. Intervention The ATEV is a bioengineered vascular conduit grown from human vascular cells, available off the shelf, and implantable without immunosuppression. Main Outcomes and Measures Primary patency at day 30 was the primary outcome. Secondary outcomes included limb salvage, graft infection, and patient survival. A systematic literature review identified synthetic graft benchmarks in the treatment of arterial trauma for the same end points. Results The arterial extremity injury subset included 51 of 69 participants in V005 and 16 of 17 participants in V017. The majority were male (V005, 38 [74.5%]; V017, 16 [100%]), the mean (SD) ages were similar (V005, 33.5 [13.6] years; V017, 34.2 [9.0] years), and the mean (SD) Injury Severity Scores were similar (V005, 20.8 [10.5]; V017, 20.1 [18.9]). Penetrating injuries dominated (V005, 29 patients [56.9%]; V017, 14 patients [87.5%]). At day 30 for the V005 and V017 trials, respectively, ATEV primary patency was 84.3% (95% CI, 72.0%-91.8%) and 93.8% (95% CI, 71.7%-98.9%); secondary patency was 90.2% (95% CI, 79.0%-95.7%) and 93.8% (95% CI, 71.7%-98.9%); amputation rate was 9.8% (95% CI, 4.3%-21.0%) and 0% (95% CI, 0.0%-19.4%); ATEV infection rate was 2.0% (95% CI, 0.4%-10.3%) and 0% (95% CI, 0.0%-19.4%); and death rate was 5.9% (95% CI, 2.0%-15.9%) and 0% (95% CI, 0.0%-19.4%) (no deaths attributed to the ATEV at day 30). Day 30 synthetic graft benchmarks were as follows: secondary patency, 78.9%; amputation, 24.3%; infection, 8.4%; and death, 3.4%. Conclusions and Relevance Results of analysis in the subset of patients with vascular extremity injuries in 2 single-arm trials in civilian and real-world military settings suggest that the ATEV provides benefits in terms of patency, limb salvage, and infection resistance. Comparing ATEV outcomes with synthetic graft benchmarks demonstrated improved outcomes in the treatment of acute vascular injuries of the extremities. The analyses reported herein are limited to the subset of 67 patients with vascular extremity injuries out of 86 patients enrolled in 2 trials and excluded 19 patients with iatrogenic and torso injuries. Had these 19 patients been included in these analyses, the efficacy and safety findings could have been attenuated. Trial Registration ClinicalTrials.gov Identifiers: NCT03005418 , NCT05873959

Objective: The aim of this study is to determine perioperative outcomes and the patency of interposition conduits for visceral arterial reconstruction in this setting. Background: Visceral arterial encasement in locally advanced pancreatic cancer was historically a contraindication for surgery. With modern, effective neoadjuvant strategies, our recent experience has made advanced vascular resection and reconstruction feasible in selected patients. Methods: A retrospective review was performed of patients undergoing pancreatic tumor resection with en bloc arterial resection and interposition revascularization between June 2002 and October 2022. Endpoints included graft patency, vascular-related complications, reinterventions, morbidity, and mortality. Results: Visceral arterial reconstruction with interposition grafting was performed in 111 patients undergoing en bloc arterial resections for pancreatic cancer. Graft types included autologous arterial conduits (n=66, 58 superficial femoral arteries (SFA) and 8 splenic arteries), cryopreserved arterial allografts (n=24), autologous saphenous veins (n=12), synthetic conduits (n=8), and composite autologous artery and synthetic (n=1). Perioperative 90-day mortality decreased significantly over time to 5% in the last 6 years. Vascular complications related to arterial reconstruction occurred in 11% (n=12) and included pseudoaneurysm (n=6), graft thrombus (n=2), stenosis requiring reintervention (n=2), hepatic failure (n=1), and hepatic and intestinal ischemia (n=1). Nine (8%) patients underwent vascular-related reinterventions. After a median follow-up of 17 months, primary patency was 81% for the entire cohort and was highest in the SFA group (95%). The donor limb/harvest site complication rate was 8% with 100% primary patency. Conclusion: Visceral arterial resection with interposition reconstruction for locally advanced pancreatic cancer can be performed with acceptable vascular morbidity and durable patency. Autologous SFA was the most suitable conduit for reconstructions in our experience, with the highest primary patency.

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.

ImportanceMilitary 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.ObservationsFrom 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 RelevanceAlthough 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.

Introduction: In seniors, the prevalence of abdominal aortic aneurysms (AAA) is high (9-10%). We aim to characterize AAA growth rates (slow vs. rapid) to help inform management strategies, including individualized imaging surveillance frequency. Hypothesis: Modeling thrombosis may improve the characterization of AAAs' growth status. Methods: 3D geometrical AAA models with and without thrombosis (vessel lumen only) were generated for 70 human subjects using available contrast-enhanced CTA data. AAA growth rates were categorized as slow (< 5 mm/year) or rapid (≥ 5 mm/year) based on serial imaging. Python scripts were used to calculate geometrical parameters (83) with and without thrombosis. Patient-specific relevant health information was retrieved through a review of medical records. Support vector machine (SVM), a well-established machine learning method, was run with 10-fold cross-validation (100 iterations) to assess the predictive accuracy. Results: Among 70 AAAs studied, the ratio between rapidly-growing and slowly-growing was nearly 1:2. The combination of antihypertensive medication, coronary artery disease, juxta-aneurysm aortic size, and five geometrical parameters quantifying the extent of thrombosis provided the best accuracy for AAA's growth status. The area under receiving operating curve (AUROC) was 0.85, and total accuracy was 0.81, with 57% and 93% of rapidly- and slowly-growing AAAs correctly identified, respectively. Excluding patients with aneurysm thrombus, the AUROC and accuracy in predicting rapidly-growing AAAs decreased to 0.82 and 48%, respectively. Conclusions: machine-learning-based predictive modeling appears feasible for characterizing AAA's growth rate status. Manual aortic image segmentation, required for data analytics, is labor-intensive (on average, 1 hour). Leveraging artificial intelligence-based segmentation methodology may provide an automated solution to improve workflow and feasibility.

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.