Soluble Glycoprotein VI Predicts Abdominal Aortic Aneurysm Growth Rate and is a Novel Therapeutic Target.

A common feature in patients with abdominal aortic aneurysms (AAA) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation impacts the pathogenesis of AAA. Using RNA-sequencing, we identify that the platelet-associated transcripts are significantly enriched in the ILT compared to the adjacent aneurysm wall and healthy control aortas. We found that the platelet specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of AAA patients. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in two independent AAA patient cohorts is highly predictive of a AAA diagnosis and associates more strongly with aneurysm growth rate when compared to D-dimer in humans. Finally, intervention with the anti-GPVI antibody (JAQ1) in mice with established aneurysms blunted the progression of AAA in two independent mouse models. In conclusion, we show that levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, where none currently exist.

TREO Aortic Endograft Demonstrates Superior Aneurysmal Sac Regression Over Mid-Term Follow-up.

INTRODUCTION: Aneurysmal sac regression is a predictor of long-term outcomes after endovascular aneurysm repair (EVAR). This study aimed to compare a large cohort of TREO and non-TREO endografts over a mid-term follow-up and compare abdominal aortic aneurysm sac regression. The hypothesis was that TREO endografts have an increased sac regression by 24 mo. METHODS: This is a retrospective analysis of all EVARs completed at a single institution between 2015 and 2024. Clinical and imaging data were collected from an institutional database and patients' records. The analysis included all TREO and age, sex, anticoagulation use and current smoking-matched non-TREO endografts that satisfied anatomic indications for use of the TREO graft. The primary outcomes were sac regression at 12 and 24 mo, and secondary outcomes were rates of mortality, endoleak, and reintervention. RESULTS: Twenty-one TREO grafts were matched to 68 non-TREO grafts. The groups were similar in demographics, comorbidities, and preoperative anatomy. Preoperative abdominal aortic aneurysm sac size was larger in the TREO cohort. The mean reduction in sac size in mm was greater in the TREO cohort compared to the non-TREO cohort (-12.6 ± 8.95 versus -7.83 ± 7.74 mm, P = 0.039) over the study period. Cox regression analysis identified the TREO stent graft to be associated with 1-y sac regression (hazard ratio = 2.42, P = 0.019). The incidence of all-cause endoleaks, reintervention, and mortality were similar between cohorts. CONCLUSIONS: These findings suggest that the TREO endograft offers better mid-term outcomes with respect to sac regression with no differences in the incidence of endoleak, mortality, or reintervention.

Early Financial Outcomes of Physician Modified Endograft Programs Are Dictated by Device Cost.

INTRODUCTION: Physician-modified endografts (PMEGs) have been used for repair of thoracoabdominal aortic aneurysms (TAAAs) for 2 decades with good outcomes but limited financial data. This study compared the financial and clinical outcomes of PMEGs to the Cook Zenith-Fenestrated (ZFEN) graft and open surgical repair (OSR). METHODS: A retrospective review of financial and clinical data was performed for all patients who underwent endovascular or OSR of juxtarenal aortic aneurysms and TAAAs from January 2018 to December 2022 at an academic medical center. Clinical presentation, demographics, operative details, and outcomes were reviewed. Financial data was obtained through the institution's finance department. The primary end point was contribution margin (CM). RESULTS: Thirty patients met inclusion criteria, consisting of twelve PMEG, seven ZFEN, and eleven open repairs. PMEG repairs had a total CM of -$110,000 compared to $18,000 for ZFEN and $290,000 for OSR. Aortic and branch artery implants were major cost-drivers for endovascular procedures. Extent II TAAA repairs were the costliest PMEG procedure, with a total device cost of $59,000 per case. PMEG repairs had 30-d and 1-y mortality rates of 8.3% which was not significantly different from ZFEN (0.0%, P = 0.46; 0.0%, P = 0.46) or OSR (9.1%, P = 0.95; 18%, P = 0.51). Average intensive care unit and hospital stay after PMEG repairs were comparable to ZFEN and shorter than OSR. CONCLUSIONS: Our study suggests that PMEG repairs yield a negative CM. To make these cases financially viable for hospital systems, device costs will need to be reduced or reimbursement rates increased by approximately $8800.

Locoregional Anesthesia's Association With Reduced Intensive Care Unit Stay After Elective Endovascular Aneurysm Repair: Impact of Temporal Changes in Practice Patterns.

BACKGROUND: Elective endovascular aneurysm repair (EVAR) can be performed via local anesthetics and/or regional (epidural or spinal) anesthesia (locoregional [LR]), versus general anesthesia (GA), conferring reduced intensive care unit (ICU) and hospital stays. Current analyses fail to account for temporal changes in vascular practice. Therefore, this study aimed to confirm reductions in ICU and hospital stays among LR patients while accounting for changes in practice patterns. MATERIALS AND METHODS: Using the Society for Vascular Surgery's Vascular Quality Initiative, elective EVARs from August 2003 to June 2021 were grouped into LR or GA. Outcomes included ICU admission and prolonged hospital stay (>2 d). Procedures were stratified into groups of 2 y periods, and outcomes were analyzed within each time period. Univariable and multivariate analyses were used to assess outcomes. RESULTS: LR was associated with reduced ICU admissions (22.3% versus 32.1%, P < 0.001) and prolonged hospital stays (14.3% versus 7.9%, P < 0.001) overall. When stratified by year, LR maintained its association with reduced ICU admissions in 2014-2015 (21.8% versus 34.0%, P < 0.001), 2016-2017 (23.6% versus 31.6%, P < 0.001), 2018-2019 (18.5% versus 30.2%, P < 0.001), and 2020-2021 (15.8% versus 28.8%, P < 0.001), although this was highly facility dependent. LR was associated with fewer prolonged hospital stays in 2014-2015 (15.6% versus 20.4%, P = 0.001) and 2016-2017 (13.3% versus 16.6%, P = 0.006) but not after 2017. CONCLUSIONS: GA and LR have similar rates of prolonged hospital stays after 2017, while LR anesthesia was associated with reduced rates of ICU admissions, although this is facility-dependent, providing a potential avenue for resource preservation in patients suitable for LR.

Perineural tumour spread in head and neck cancer: a pictorial review.

Perineural tumour spread in head and neck cancer can be a challenging diagnosis for radiologists; head and neck anatomy is intimidating and perineural tumour spread can be subtle and difficult to detect. It results in significant morbidity for patients, can upstage disease and will frequently result in more prolonged treatment courses. This pictorial review provides a thorough examination of the imaging characteristics of perineural tumour spread in head and neck malignancy. It highlights key imaging features, from initial diagnosis to its post-therapy appearance, emphasising the clinical relevance and role of imaging in post-therapy assessment. Multi-modality imaging examples are included with a focus on magnetic resonance imaging (MRI) and positron-emission tomography (PET)/computed tomography (CT). MRI features of perineural tumour spread include intermediate T2 signal expansion of a nerve, abnormal enhancement extending along a nerve, expansion of a skull or neural foramen and loss of normal fat planes surrounding nerve pathways. 18F-fluorodeoxyglucose (FDG) PET/CT is a useful adjunct to MRI, perineural tumour spread results in abnormal FDG accumulation in a linear fashion anatomically spreading along a nerve pathway. Knowledge of these features and useful check areas will ensure that radiologists can be confident both in making the diagnosis and re-assessment post-therapy.

Impact of calcified plaque volume on technical and 3-year outcomes after transcarotid artery revascularization.

OBJECTIVE: We sought to quantify the percent calcification within carotid artery plaques and assess its impact on percent residual stenosis and rate of restenosis in patients undergoing transcarotid artery revascularization for symptomatic and asymptomatic carotid artery stenosis. METHODS: A retrospective review of prospectively collected institutional Vascular Quality Initiative data was performed to identify all patients undergoing transcarotid artery revascularization from December 2015 to June 2021 (n = 210). Patient and lesion characteristics were extracted. Using a semiautomated workflow, preoperative computed tomography head and neck angiograms were analyzed to determine the calcified plaque volume in distal common carotid artery and internal carotid artery plaques. Intraoperative digital subtraction angiograms were reviewed to calculate the percent residual stenosis post-intervention according to North American Symptomatic Carotid Endarterectomy Trial criteria. Peak systolic velocity and end-diastolic velocity were extracted from outpatient carotid duplex ultrasound examinations. Univariate logistic regression was performed to analyze the relationship of calcium volume percent and Vascular Quality Initiative lesion calcification to percent residual stenosis in completion angiograms. Kaplan-Meier analysis examined the relationship between calcium volume percent and in-stent stenosis over 36 months. RESULTS: One hundred ninety-seven carotid arteries were preliminarily examined. Predilation was performed in 87.4% of cases with a mean balloon diameter of 5.1 ± 0.7 mm and a mean stent diameter was 8.8 ± 1.1 mm. The mean calcium volume percent was 11.9 ± 12.4% and the mean percent residual stenosis was 16.1 ± 15.6%. Univariate logistic regression demonstrated a statistically significant difference between calcium volume percent and percent residual stenosis (odds ratio [OR], 1.324; 95% confidence interval [CI], 1.005-1.746; P = .046). Stratified by quartile, only the top 25% of calcified plaques (>18.7% calcification) demonstrated a statistically significant association with higher percent residual stenosis (OR, 2.532; 95% CI, 1.049-6.115; P =.039). There was no statistical significance with lesion calcification (OR, 1.298; 95% C,: 0.980-1.718; P = .069). A Kaplan-Meier analysis demonstrated a statistically significant increase in the rate of in-stent stenosis during a 36-month follow-up for lesions containing >8.2% calcium volume (P = .0069). CONCLUSIONS: A calcium volume percent of >18.7% was associated with a higher percent residual stenosis, and a calcium volume percent of >8.2% was associated with higher in-stent stenosis at 36 months. There was one clinically diagnosed stroke during the follow-up period, demonstrating the overall safety of the procedure.

Locoregional anesthesia is associated with reduced hospital stay and need for intensive care unit care of elective endovascular aneurysm repair patients in the Vascular Quality Initiative.

OBJECTIVE: It has been shown local or regional anesthetic techniques are a feasible alternative to general anesthesia for endovascular aortic aneurysm repair (EVAR). However, studies to date have shown controversial findings with respect to the benefit of locoregional anesthesia (LR) in the elective setting. The objective of this study is to compare postoperative outcomes between LR and general anesthesia (GA) in the setting of elective EVAR, using a large, multicenter database. METHODS: Using the Society for Vascular Surgery Vascular Quality Initiative database, we retrospectively analyzed all patients who underwent elective EVAR from August 2003 to June 2021. Patients were grouped by anesthetic type based on the level of consciousness afforded by the anesthetic: local or regional anesthesia (LR) vs GA. Primary outcomes were total postoperative hospital length-of-stay (LOS) and intensive care unit (ICU) LOS. Propensity score matching was used for risk adjustment and to analyze the primary outcomes with confirmatory analysis using logistic or linear regression, as appropriate, in single and multilevel models. Secondary outcomes were 30-day mortality, 1-year mortality, postoperative outcomes, operative time, fluoroscopy time, and reoperation rate. These were analyzed following propensity score matching as well as using logistic regression and Cox proportional hazard regression in single and multilevel models, as appropriate. RESULTS: A total of 50,809 patients underwent elective EVAR from 2003 to 2021. Of these, 4302 repairs used LR (8.5%) and 46,507 (91.5%) were performed under GA. After employing propensity score matching, two groups of 3027 patients were produced. These showed no significant difference in 30-day mortality (odds ratio, 1.22; P = .53), 1-year mortality (hazard ratio, 1.06; P = .62), or any postoperative outcomes. LR was found to be significantly associated with shorter hospital stays (≤2 days) (12.5% vs 14.8%; P = .01), decreased ICU utilization (19.3% vs 30.6%; P < .001), decreased operative time (110.8 vs 117.3 minutes; P < .001), decreased fluoroscopy time (21.0 vs 22.7 minutes; P < .001), and a slight reduction in reoperation rate (1.2% vs 1.9%; P = .02), which all remained significant following single-level and multilevel multivariate analyses accounting for hospital and physician random effects. CONCLUSIONS: These data suggest that LR anesthesia is safe and may offer advantages in reducing resource utilization for patients undergoing elective EVAR, primarily based on associations with reduced ICU care and reduced hospital stay. Given these findings, LR may prove an advantageous technique in appropriately selected patient populations.

Survival, Reintervention, and Value of Open and Endovascular Repair for Chronic Mesenteric Ischemia.

BACKGROUND: There are limited analyses of survival and postoperative outcomes in chronic mesenteric ischemia (CMI) using data from large cohorts. Current guidelines recommend open repair (OR) for younger, healthier patients when long-term benefits outweigh increased perioperative risks or for poor endovascular repair (ER) candidates. This study investigates whether long-term survival, reintervention, and value differ between these treatment modalities. METHODS: A retrospective cohort analysis was performed on data extracted from the Statewide Planning and Research Cooperative System, the New York statewide all-payer database containing demographics, diagnoses, treatments, and charges. Patients were selected for CMI and subsequent ER or OR using International Classification of Diseases, Ninth Revision codes. Patients with peripheral arterial disease were excluded to account for ambiguity in the International Classification of Diseases, Ninth Revision procedure code for angioplasty of noncoronary vessels, which includes angioplasty of upper and lower extremity vessels. Kaplan-Meier analysis was used to compare 1-year and 5-year survival and reintervention between treatment modalities using a propensity-matched cohort. Cox proportional hazards testing was performed to find factors associated with 1-year and 5-year survival and reintervention. Analysis of procedural value was performed using linear regression. RESULTS: From 2000 to 2014, 744 patients met inclusion criteria. Of these, 209 (28.1%) underwent OR and 535 (71.9%) ER. No difference between propensity-matched groups was found in 1-year (P = 0.46) or 5-year (P = 0.91) survival. Congestive heart failure (hazard ratio [HR]: 2.8, 95% confidence interval [CI]: 1.7-4.4; P < 0.01), cancer (HR: 2.8, 95% CI: 1.3-5.8; P < 0.01), and dysrhythmia (HR: 1.8, 95% CI: 1.1-2.8; P = 0.02) correlated with 1-year mortality. Cancer (HR: 2.9, 95% CI: 1.6-5.5; P < 0.01), congestive heart failure (HR: 2.2, 95% CI: 1.5-3.2; P < 0.01), chronic pulmonary disease (HR: 1.4, 95% CI: 1.0-2.0; P = 0.04), and age (HR: 1.03, 95% CI: 1.01-1.05; P < 0.01) correlated with 5-year mortality. Treatment modality was not associated with reintervention at 1 year on Kaplan-Meier analysis (P = 0.29). However, ER showed increased instances of reintervention at 5 years (P < 0.01). Additionally, ER was associated with an increased 5-year value (0.7 ± 0.9 vs. 0.5 ± 0.5 life years/charges at index admission [$10k], P < 0.01; b coefficient: 0.2, 95% CI: 0.1-0.4, P < 0.01). CONCLUSIONS: This is the largest retrospective propensity-matched single-study cohort to analyze long-term survival outcomes after intervention for CMI. Long-term mortality was independent of treatment modality and rather was associated with patient comorbidities. Therefore, treatment selection should depend on anatomic considerations and long-term value. ER should be considered over OR in patients with amenable anatomy based on the superior procedural value.

Apelin protects against abdominal aortic aneurysm and the therapeutic role of neutral endopeptidase resistant apelin analogs.

Abdominal aortic aneurysm (AAA) remains the second most frequent vascular disease with high mortality but has no approved medical therapy. We investigated the direct role of apelin (APLN) in AAA and identified a unique approach to enhance APLN action as a therapeutic intervention for this disease. Loss of APLN potentiated angiotensin II (Ang II)-induced AAA formation, aortic rupture, and reduced survival. Formation of AAA was driven by increased smooth muscle cell (SMC) apoptosis and oxidative stress in Apln-/y aorta and in APLN-deficient cultured murine and human aortic SMCs. Ang II-induced myogenic response and hypertension were greater in Apln-/y mice, however, an equivalent hypertension induced by phenylephrine, an α-adrenergic agonist, did not cause AAA or rupture in Apln-/y mice. We further identified Ang converting enzyme 2 (ACE2), the major negative regulator of the renin-Ang system (RAS), as an important target of APLN action in the vasculature. Using a combination of genetic, pharmacological, and modeling approaches, we identified neutral endopeptidase (NEP) that is up-regulated in human AAA tissue as a major enzyme that metabolizes and inactivates APLN-17 peptide. We designed and synthesized a potent APLN-17 analog, APLN-NMeLeu9-A2, that is resistant to NEP cleavage. This stable APLN analog ameliorated Ang II-mediated adverse aortic remodeling and AAA formation in an established model of AAA, high-fat diet (HFD) in Ldlr-/- mice. Our findings define a critical role of APLN in AAA formation through induction of ACE2 and protection of vascular SMCs, whereas stable APLN analogs provide an effective therapy for vascular diseases.

Introduction to the National Cancer Imaging Translational Accelerator (NCITA): a UK-wide infrastructure for multicentre clinical translation of cancer imaging biomarkers.

The National Cancer Imaging Translational Accelerator (NCITA) is creating a UK national coordinated infrastructure for accelerated translation of imaging biomarkers for clinical use. Through the development of standardised protocols, data integration tools and ongoing training programmes, NCITA provides a unique scalable infrastructure for imaging biomarker qualification using multicentre clinical studies.

Variation in esophageal anastomosis technique-the role of collaborative learning.

Centralization of care has improved outcomes in esophagogastric (EG) cancer surgery. However, specialist surgical centers often work within clinical silos, with little transfer of knowledge and experience. Although variation exists in multiple dimensions of perioperative care, the differences in operative technique are rarely studied. An esophageal anastomosis workshop was held to identify areas of common and differing practice within the operative technique. Surgeons showed videos of their anastomosis technique by open and minimally invasive surgery. Each video was followed by a discussion. Surgeons from 10 different EG cancer centers attended. Eight key technical differences and learning points were identified and discussed: the optimum diameter of the gastric conduit; avoiding ischemia in the gastric conduit; minimizing esophageal trauma; the use of an esophageal mucosal collar; omental wrapping; intraoperative leak testing; ideal diameter of the circular stapler and the growing use of linear stapled anastomoses. The workshop received positive feedback from participants and on 2 years follow-up, 40% stated that they believed that the learning of tips and techniques during the workshop has contributed to lowering their anastomotic leak rate. Many differences exist in surgical technique. The reasons for, and crucially the significance of, these differences must be discussed and examined. Workshops provide a forum for peer-to-peer collaborative learning to reflect on one's own practice and improve surgical technique. These changes can, in turn, generate incremental improvements in patient care and postoperative outcomes.

Hypoxia and Ischemia Promote a Maladaptive Platelet Phenotype.

OBJECTIVE: Reduced blood flow and tissue oxygen tension conditions result from thrombotic and vascular diseases such as myocardial infarction, stroke, and peripheral vascular disease. It is largely assumed that while platelet activation is increased by an acute vascular event, chronic vascular inflammation, and ischemia, the platelet activation pathways and responses are not themselves changed by the disease process. We, therefore, sought to determine whether the platelet phenotype is altered by hypoxic and ischemic conditions. APPROACH AND RESULTS: In a cohort of patients with metabolic and peripheral artery disease, platelet activity was enhanced, and inhibition with oral antiplatelet agents was impaired compared with platelets from control subjects, suggesting a difference in platelet phenotype caused by the disease. Isolated murine and human platelets exposed to reduced oxygen (hypoxia chamber, 5% O2) had increased expression of some proteins that augment platelet activation compared with platelets in normoxic conditions (21% O2). Using a murine model of critical limb ischemia, platelet activity was increased even 2 weeks postsurgery compared with sham surgery mice. This effect was partly inhibited in platelet-specific ERK5 (extracellular regulated protein kinase 5) knockout mice. CONCLUSIONS: These findings suggest that ischemic disease changes the platelet phenotype and alters platelet agonist responses because of changes in the expression of signal transduction pathway proteins. Platelet phenotype and function should, therefore, be better characterized in ischemic and hypoxic diseases to understand the benefits and limitations of antiplatelet therapy.

Implementing diffusion-weighted MRI for body imaging in prospective multicentre trials: current considerations and future perspectives.

For body imaging, diffusion-weighted MRI may be used for tumour detection, staging, prognostic information, assessing response and follow-up. Disease detection and staging involve qualitative, subjective assessment of images, whereas for prognosis, progression or response, quantitative evaluation of the apparent diffusion coefficient (ADC) is required. Validation and qualification of ADC in multicentre trials involves examination of i) technical performance to determine biomarker bias and reproducibility and ii) biological performance to interrogate a specific aspect of biology or to forecast outcome. Unfortunately, the variety of acquisition and analysis methodologies employed at different centres make ADC values non-comparable between them. This invalidates implementation in multicentre trials and limits utility of ADC as a biomarker. This article reviews the factors contributing to ADC variability in terms of data acquisition and analysis. Hardware and software considerations are discussed when implementing standardised protocols across multi-vendor platforms together with methods for quality assurance and quality control. Processes of data collection, archiving, curation, analysis, central reading and handling incidental findings are considered in the conduct of multicentre trials. Data protection and good clinical practice are essential prerequisites. Developing international consensus of procedures is critical to successful validation if ADC is to become a useful biomarker in oncology. KEY POINTS: • Standardised acquisition/analysis allows quantification of imaging biomarkers in multicentre trials. • Establishing "precision" of the measurement in the multicentre context is essential. • A repository with traceable data of known provenance promotes further research.

Effects of intraoperative pyloric stretch procedure on outcomes after esophagectomy.

Various methods have been described to aid pyloric drainage in patients undergoing esophagectomy with gastric reconstruction. These techniques are intended to prevent delayed gastric empting following esophagectomy that can be associated with early morbidity and long-term functional complaints. The current study aims to review the safety and efficacy of a pyloric stretch procedure performed at the time of esophagectomy. To achieve this, a retrospective review of 100 consecutive patients undergoing esophagectomy during the period 2011-2016 was performed. Until May 2013, no patients received intraoperative pyloric intervention. After May 2013, all patients (N = 50) underwent intraoperative pyloric stretch procedure that involved bidirectional mechanical dilatation of the pylorus. Postoperative outcomes including result of routine oral contrast swallow and early morbidity were evaluated. Intraoperative pyloric stretching was performed safely and without local complications in all patients. Delayed gastric emptying was observed significantly less frequently in patients who received intraoperative pyloric stretching (48% vs. 22%, P = 0.006). No significant differences were observed in postoperative outcomes. When considering all patients as a single cohort, the presence of delayed gastric emptying was associated with significantly higher rates of postoperative pneumonia (71% vs. 45%, P = 0.010), cardiac complications (57% vs. 25%, P = 0.001) as well as longer hospital say (12 vs. 15 days, P < 0.001) and delay to free oral fluid intake (7 vs. 9 days, < 0.001). Binary logistic regression identified age and postoperative delayed gastric emptying as independent risk factors for postoperative pneumonia. In conclusion, this study has demonstrated the safety and efficacy an intraoperative pyloric stretch procedure for the prevention of delayed gastric emptying following esophagectomy.

Outcomes for critical limb ischemia are driven by lower extremity revascularization volume, not distance to hospital.

OBJECTIVE: The objective of this study was to identify relationships among geographic access to care, vascular procedure volume, limb preservation, and survival in patients diagnosed with critical limb ischemia (CLI). METHODS: Using New York State administrative data from 2000 to 2013, we identified a patient's first presentation with CLI defined by International Classification of Diseases, Ninth Revision diagnosis and procedure codes. Distance from the patient's home to the index hospital was calculated using the centroids of the respective ZIP codes. A multivariable logistic regression model was employed to estimate the impact of distance, major lower extremity amputation (LEA) volume, and lower extremity revascularization (LER) volume on major amputation and 30-day mortality. Volumes and distances were analyzed in quintiles. The farthest distance quintile and the highest procedure volume quintiles were used as references for generating odds ratios (ORs). RESULTS: There were 49,576 patients identified with an initial presentation of CLI. The median age was 73 years, 35,829 (73.2%) had Medicare as a primary insurer, 11,395 (23.0%) had a major amputation, and 4249 (8.6%) died within 30 days of admission. Patients in the closest distance quintile were more likely to undergo amputation (OR, 1.53 [1.39-1.68]; P < .0001). Patients who visited hospitals in the lowest LER volume quintile with at least one procedure per year faced higher 30-day mortality rates (OR, 2.05 [1.67-2.50]; P < .0001) and greater odds of amputation (OR, 9.94 [8.5-11.63]; P < .0001). Patients who visited hospitals in the lowest LEA volume quintile had lower odds of 30-day mortality (OR, 0.66 [0.50-0.87]; P = .0033) and lower odds of amputation (OR, 0.180 [0.142-0.227]; P < .0001). CONCLUSIONS: Rates of major amputation are inversely associated with distance from the index hospital, whereas rates of both major amputation and mortality are inversely associated with LER volume. Rates of major amputation and mortality are directly associated with LEA volume. We believe that unless it is otherwise contraindicated, these data support consideration for selective referral of CLI patients to high-volume centers for LER regardless of distance. Within the context of value-based health care delivery, policy supporting regionalization of CLI care into centers of excellence may improve outcomes for these patients.

Stenting of a hepatic artery pseudoaneurysm rupture secondary to a celiac artery dissection.

Hepatic artery (HA) pseudoaneurysm rupture is a rare and potentially lethal pathology. We present the case of a celiac artery dissection complicated by an HA pseudoaneurysm rupture that was treated successfully with endovascular stenting. The patient's postoperative course was uncomplicated, and he was further evaluated for an underlying connective tissue disorder. There is no standard treatment for a ruptured HA pseudoaneurysm, although transarterial embolization is most frequently reported. This report demonstrates that self-expanding stent grafts are effective in the emergent repair of HA pseudoaneurysm rupture.

Ultrasound elastography to quantify average percent pressure-normalized strain reduction associated with different aortic endografts in 3D-printed hydrogel phantoms.

Objective: Strain has become a viable index for evaluating abdominal aortic aneurysm stability after endovascular aneurysm repair (EVAR). In addition, literature has shown that healthy aortic tissue requires a degree of strain to maintain homeostasis. This has led to the hypothesis that too much strain reduction conferred by a high degree of graft oversizing is detrimental to the aneurysm neck in the seal zone of abdominal aortic aneurysms after EVAR. We investigated this in a laboratory experiment by examining the effects that graft oversizing has on the pressure-normalized strain ( ε ρ + ¯ /pulse pressure [PP]) reduction using four different infrarenal EVAR endografts and our ultrasound elastography technique. Approximate graft oversizing percentages were 20% (30 mm phantom-graft combinations), 30% (28 mm phantom-graft combinations), and 50% (24 mm phantom-graft combinations). Methods: Axisymmetric, 10% by mass polyvinyl alcohol phantoms were connected to a flow simulator. Ultrasound elastography was performed before and after implantation with the four different endografts: (1) 36 mm polyester/stainless steel, (2) 36 mm polyester/electropolished nitinol, (3) 35 mm polytetrafluoroethylene (PTFE)/nitinol, and (4) 36 mm nitinol/polyester/platinum-iridium. Five ultrasound cine loops were taken of each phantom-graft combination. They were analyzed over two different cardiac cycles (end-diastole to end-diastole), yielding a total of 10 maximum mean principal strain ( ε ρ + ¯ ) values. ε ρ + ¯ was divided by pulse pressure to yield pressure-normalized strain ( ε ρ + ¯ /PP). An analysis of variance was performed for graft comparisons. We calculated the average percent ε ρ + ¯ /PP reduction by manufacturer and percent oversizing. These values were used for linear regression analysis. Results: Results from one-way analysis of variance showed a significant difference in ε ρ + ¯ /PP between the empty phantom condition and all oversizing conditions for all graft manufacturers (F(3, 56) = 106.7 [graft A], 132.7 [graft B], 106.5 [graft C], 105.7 [graft D], P < .0001 for grafts A-D). There was a significant difference when comparing the 50% condition with the 30% and 20% conditions across all manufacturers by post hoc analysis (P < .0001). No significant difference was found when comparing the 20% and 30% oversizing conditions for any of the manufacturers or when comparing ε ρ + ¯ /PP values across the manufacturers according to percent oversize. Linear regression demonstrated a significant positive correlation between the percent graft oversize and the all-graft average percent ε ρ + ¯ /PP reduction ( R 2  = 0.84, P < .0001). Conclusions: This brief report suggests that a 10% increase in graft oversizing leads to an approximate 5.9% reduction in ε ρ + ¯ /PP on average. Applied clinically, this increase may result in increased stiffness in axisymmetric vessels after EVAR. Further research is needed to determine if this is clinically significant.

16(th) IHIW: global distribution of extended HLA haplotypes.

This report describes the project to identify the global distribution of extended HLA haplotypes, a component of 16th International HLA and Immunogenetics Workshop (IHIW), and summarizes the initial analyses of data collected. The project aims to investigate extended HLA haplotypes, compare their distribution among different populations, assess their frequency in hematopoietic stem cell unrelated donor registries and initiate an international family studies database and DNA repository to be made publicly available. HLA haplotypes compiled in immunogenetics laboratories during the evaluation of transplant candidates and related potential donors were analysed. Haplotypes were determined using the pedigree analysis tool publicly available from the National Marrow Donor Program (NMDP) website. Nineteen laboratories from 10 countries (11 laboratories from North America, five from Asia, two from Latin America and one from Australia) contributed data on a total of 1719 families comprised of 7474 individuals. We identified 10393 HLA haplotypes, of which 1682 haplotypes included high-resolution typing at HLA-A, B, C, DRB1 and DQB1 loci. We also present haplotypes containing MICA and other HLA loci and haplotypes containing rare alleles seen in these families. The project will be extended through the 17th IHIW, and investigators interested in joining the project may communicate with the first author.

Gore TAG thoracic branch endograft for treatment of a subacute type B aortic dissection complicated by rupture.

An 80-year-old man presented with a subacute zone 3-5 type B aortic dissection complicated by rupture and visceral and lower extremity malperfusion. He underwent emergent zone 2 repair with a Gore TAG thoracic branch endograft with inclusion of the left subclavian artery for a dominant left vertebral artery. The patient's postoperative course was uncomplicated. Type B aortic dissections can be anatomically complex, and rupture is a rare complication in the subacute phase. We report the novel use of a Gore TAG thoracic branch endograft for the management of type B aortic dissection complicated by rupture and demonstrate its feasibility for patients with type B aortic dissection complicated by rupture.