Female sex is independently associated with in-hospital mortality after endovascular aortic repair for ruptured aortic aneurysm

OBJECTIVE

Endovascular aortic repair (EVAR) can treat anatomically compatible ruptured abdominal aortic aneurysms (rAAA), but registry data suggests that women undergo more open abdominal aneurysm repairs than men. We evaluate in-hospital outcomes of EVAR for rAAA by sex.

METHODS

The Vascular Quality Initiative (VQI) registry was queried from 2013 to 2019 for rAAA patients treated with EVAR. Univariate analysis was performed with Student's t-test and chi-squared tests. Multivariable logistic regression was then performed to assess the association between female sex and inpatient mortality.

RESULTS

1775 patients were included (23.8% female). Female rAAA patients were older (p < 0.01) and weighed less (p < 0.01). They were less likely to have smoked (p <. 001) and had lower creatinine (1.29 vs 1.43, p <0.01) and hemoglobin (10.7 vs 11.7, p < 0.01). Women had smaller maximum aortic diameters (74 vs 66 mm, p < 0.01) and were less likely to have iliac aneurysms (p <.001). Women were more likely to have concomitant femoral endarterectomy (8.5% vs 4.6%, p=.03). Despite having no significant difference in complication or reintervention rates, women had higher rates of in-hospital mortality (45.9% vs 34.5%, p < 0.01). In a logistic regression model for predictors of in-hospital mortality (χ² < .01), increased age (OR 1.08, p < 0.01), female sex (OR 1.7, p=0.02), preoperative cardiac arrest (OR 5.29, p<0.01), concurrent iliac stenting (OR 2.38, p =0.02), postoperative mesenteric ischemia (OR 2.51, p<0.01) and postoperative transfusion (OR 1.06, p <0.01) were independently associated with in-hospital mortality. Increased preoperative hemoglobin was protective (OR 0.89, p < 0.01) CONCLUSIONS: Female sex is independently associated with in-hospital mortality after EVAR for rAAA, suggesting a relationship beyond anatomical, biochemical, and procedural covariates.

Validity Evidence for Vascular Skills Assessment: The Feasibility of Fundamentals of Vascular Surgery in General Surgery Residency

OBJECTIVE

As the Fundamentals of Laparoscopic Surgery (FLS) and Fundamentals of Endoscopic Surgery (FES) have been used for general surgery assessment, the Fundamentals of Vascular Surgery (FVS) has recently been developed to evaluate core operative skills for vascular trainees. This study examines the 3 year implementation of FVS for general surgery residents and it gathers validity evidence using Messick's framework. We hypothesized that the curriculum and assessment tool enhance general surgery resident training and assessment.

DESIGN

This is a retrospective review of FVS assessments of residents using descriptive and multivariate analyses.

SETTING

This study was conducted at an academic institution, where simulation-based teaching sessions occur in coordination between the general surgery and the integrated vascular surgery residency programs.

PARTICIPANTS

Seventeen general surgery residents were assessed in FVS skills by an expert rater from 2018 to 2020.

RESULTS

Overall, 86 assessments were completed.

CONTENT

Assessment focuses on 3 open vascular skills (End-to-Side Anastomosis, Patch Angioplasty and Clockface Suturing). Response Process: 7 items comprise a graded rating for a skills score. Additionally, a global summary score is designated. Internal Structure: The assessment tool has a Cronbach's alpha of 0.87, demonstrating good internal consistency. Addition of the second rater correlated with Cohen's kappa -0.69 (p < 0.001), indicating poor interrater reliability. Relationships to other variables: The most significant improvement occurred in total scores between PGY2s (17.4 ± 2.37) and PGY4s (23.2 ± 3.00), p < 0.001, indicating adequate level discernment.

CONCLUSIONS

The validity evidence of FVS assessment in this study supports its use in general surgery residency at a time when opportunities for open vascular skills assessment may be decreasing due to case availability and shifting paradigms. Further study into quality rater training is needed to optimize national implementation of FVS and ensure consistency in grading.

Cancer-Associated Venous Thromboembolic Disease, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cancer-Associated Venous Thromboembolic Disease focus on the prevention, diagnosis, and treatment of patients with cancer who have developed or who are at risk for developing venous thromboembolism (VTE). VTE is a significant concern among cancer patients, who are at heightened risks for developing as well as dying from the disease. The management of patients with cancer with VTE often requires multidisciplinary efforts at treating institutions. The NCCN panel comprises specialists from various fields: cardiology, hematology/hematologic oncology, internal medicine, interventional radiology, medical oncology, pharmacology/pharmacy, and surgery/surgical oncology. This article focuses on VTE prophylaxis for medical and surgical oncology inpatients and outpatients, and discusses risk factors for VTE development, risk assessment tools, as well as management methods, including pharmacological and mechanical prophylactics. Contraindications to therapeutic interventions and special dosing, when required, are also discussed.

Fenestrated endovascular repair with large device diameters (34- to 36-mm) is associated with type 1 and 3 endoleak and reintervention

OBJECTIVES

 Patients with abdominal aortic aneurysms undergoing EVAR with larger device diameters (34- to 36-mm) have worse outcomes due to proximal fixation failure and need for reintervention. We examine outcomes relating to standard fenestrated repair (FEVAR) with larger device diameters, and investigate whether a similar relationship exists.

MATERIAL AND METHODS

 Retrospective review of a prospectively maintained, single institution database of patients treated with the Cook ZFEN device between 2012-2017. Outcomes were stratified by device diameter into normal-diameter (ND,≤ 32 mm) and large-diameter (LD,34-36 mm). Primary endpoints were need for reintervention and composite type I/III endoleak.

RESULTS

 100 consecutive patients treated were identified for inclusion. Overall mean age was 73.6 years and mean aortic diameter was 59.1 mm. Mean follow-up was 22 months. A total of 26 (26%) patients were treated with LD devices. Number of target vessels per patient was 2.8 in both groups. Infrarenal neck length and diameter were significantly different in the LD and ND patients, respectively (2.6 mm vs 4.7 mm (P<.01) and 30.1 mm vs 23.4 mm (P<.01)). Percent graft oversizing was lower in the LD cohort (19% vs 24%; P=.006). No difference was seen in overall mortality at 30-days (0% vs 2%; P=.4) or at latest follow up (6% vs 14%; P=.6). Reinterventions were not significantly different at 30 days, but were significantly higher over the follow-up period in the LD cohort (46.2 vs. 17.6%; P=.002). LD diameter was associated with reintervention on univariate (HR 1.19, 95% CI 1.04-1.37), but not multivariate analysis. The composite endpoint of type I/III endoleak was higher in the LD cohort (15.4% vs. 2.7%; P=.004).

CONCLUSION

 FEVAR requiring 34- or 36-mm device diameters is associated with an increased risk of composite type I/III endoleak and reintervention. Patients undergoing fenestrated repair requiring LD devices should be closely monitored, with consideration for proximal or open repair.

Analysis of Medicare Payments and Patient Outcomes With Pre-Operative Imaging for Carotid Endarterectomy

OBJECTIVE

The use of radiographic evaluation of carotid disease may vary, and current guidelines do not strongly recommend the use of cross-sectional imaging (CSI) prior to surgical intervention. We sought to describe the trends in preoperative carotid imaging and evaluate the associated clinical outcomes and Medicare payments for patients undergoing carotid endarterectomy (CEA) for asymptomatic carotid disease.

METHODS

We used a 20% Medicare sample from 2006 to 2014 identifying patients undergoing CEA for asymptomatic disease. We evaluated preoperative carotid ultrasound and CSI use: CT or MRI of the neck prior to CEA. We calculated average payments of each study from the carrier file and revenue center file. Imaging payments included both the professional component (PC) and the technical component (TC). Claims with a reimbursement of $0 and studies where payment for both the TC and PC could not be identified were excluded from the overall calculation to determine average payment per study. Inpatient reimbursements according to DRG 37-39 were calculated. We compared hospital length of stay (LOS), in hospital stroke, carotid re-exploration, and mortality according to CSI use.

RESULTS

A total of 58,993 CEAs were identified with pre-operative carotid imaging. The average age was 74.8 ± 7.5 years, and 56.0% were men. A total of 19,678 (33%) patients had ultrasound alone with an average of (2.4 ± 1.9) exams prior to CEA. A total of 39,315 patients underwent CSI prior to CEA with 2.5 ± 2.1 ultrasounds, 0.95 ± 0.86 neck CTs and 0.47 ± 0.7 MRIs per patient. The average payment for ultrasound was $140 ± 40, $282 ± 94 for CT and $410 ± 146 for MRI. The average inpatient reimbursements were $7,413 ± 4,215 for patients without CSI compared with $7,792 ± 3,921 for patients with CSI, P < 0.001. The average LOS during CEA admission was 2.5 ± 3.7days. Patients with CSI had a slightly lower percentage of patients being discharged by postoperative day 2 compared with ultrasound alone (88.9% vs. 91.5%, respectively, P < 0.001). The overall in-hospital stroke rate was 0.38% and carotid re-exploration rate was 1.0% and there was no statistical significant difference between groups. Median follow-up was 3.9 years, and mortality at 8 years was 50% and did not statistically differ between groups.

CONCLUSIONS

Our analysis found preoperative imaging to include CSI in nearly two-thirds of patients prior to CEA for asymptomatic disease. As imaging and inpatient payments were higher with patients with CSI further work is needed to understand when CSI is appropriate prior to surgical intervention to appropriately allocate healthcare resources.

Effect of a Swing-Assist Knee Prosthesis on Stair Ambulation

This paper describes stair ambulation control and functionality of a semi-powered knee prosthesis that supplements nominally passive prosthesis behavior with swing-phase assistance. A set of stair ascent and descent controllers are described. The controllers were implemented in a semi-powered prosthesis prototype, and the prospective benefits of swing assist in stair ambulation were assessed on a group of three participants with unilateral, transfemoral amputation, relative to their respective daily-use prostheses. Results indicate that ambulation with the semi-powered knee resulted in improved stair ascent gait symmetry when compared to the participants' passive daily-use devices, and increased similitude to healthy stair ascent movement.

Predictors of sac regression after fenestrated endovascular aneurysm repair

OBJECTIVE

Aneurysm sac regression after standard endovascular aortic repair is associated with improved outcomes, but similar data are limited after fenestrated endovascular aortic repair (FEVAR). We sought to evaluate sac regression after FEVAR, and identify any predictors of this favorable outcome.

METHODS

Patients undergoing elective FEVAR using the commercially available Zenith Fenestrated device (ZFEN; Cook Medical, Bloomington, IN) from 2012 to 2018 at a single institution were reviewed retrospectively. The maximal aortic diameter was compared between the preoperative scan and those obtained in follow-up. Patients with of 5 mm or more sac regression were included in the regression (REG) group, with all others in the nonregression (NONREG) group. Outcomes were compared between groups using univariate analysis, and logistic regression analysis was performed to identify any predictive factors for sac regression.

RESULTS

We included 132 patients undergoing FEVAR in the analysis. At a mean follow-up of 33.1 months, 65 patients (49.2%) had sac regression of 5 mm or more and comprised the REG group (n = 65 [49.2%]). The REG group had smaller diameter devices, and were less likely to have had concomitant chimney grafts placed (P < .05). The NONREG group had a higher incidence of type II endoleak (35.8% vs 12.3%; P = .002). Sac regression was associated with a significant mortality benefit on Kaplan-Meier analysis (log rank P = .02). Multivariate analysis identified adjunctive parallel grafting (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.03-0.36; P < .01), persistent type II endoleak (OR, 0.13; 95% CI, 0.02-0.74; P < .01), and a greater number of target vessels (OR, 0.25; 95% CI, 0.10-0.62; P = .002) as independent predictors of failure to regress.

CONCLUSIONS

Sac regression after FEVAR occurred in nearly one-half of patients, but seems to be less common in patients with persistent type II endoleaks and those undergoing concomitant parallel grafting. Sac regression was associated with a significant survival advantage, and can be used as a clinical marker for success after FEVAR.

Interview Experience, Post-interview Communication and Gender-based Differences in the Integrated Vascular Surgery Residency Match

OBJECTIVE

Integrated vascular surgery residency (IVSR) applicant perspective about the Match process has been rarely studied, yet has important implications on trainee recruitment. We sought to better understand the nature of the interview process, and post-interview communication and its impact on students' ranking choices.

METHODS

A voluntary and anonymous survey was sent to students who matched to IVSR in 2020, inquiring about interviews, post-interview communications and factors influencing students' rank-lists.

RESULTS

70 of the 73 matched students completed the survey (96% response rate; 23 female and 47 male). Applicants reported they were asked questions about other programs of interest (81.4%), top choice programs (65.7%), marital-status (32.9%), family-planning (7.1%) and religion (1.4%) during interviews. Female applicants were more frequently asked questions about family-planning (17.4% vs 2.1%; P<.01) and marital-status (52.5% vs 23.4%; P <.01) compared to male applicants. After interviews, 92.9% of applicants notified their top choice program of their ranking preference. 61.4% of applicants received post-interview communication with regards to ranking from at least one program, initiated by program directors in 81.3% of instances. Among these applicants, 58.1% reported that the post-interview communication had an impact on their rank-list and 46.5% matched at a program by which they were contacted. 5.7% of applicants were asked by a program to reveal their ranking of the program and 11.4% were promised by a program to be ranked first if the applicant reciprocally ranked them first. Female and male applicants weighed program culture, operative volume, mentorship and prestige equally in making their rank-list. Male applicants weighed the sub-internship experience more significantly; however, female applicants weighed the sub-internship experience, personal relationships in certain cities, dedicated professional development years and large female representation in the program more heavily (P<.02).

CONCLUSIONS

This study provides insight into the interview experience and impactful factors for the vascular surgery match. Both female and male applicants were asked a high number of questions about personal matters unrelated to medical school performance. Female applicants, however, experienced a higher proportion of these instances, particularly regarding family-planning. These findings demonstrate the factors that are important to applicants in the match process and raises awareness of potential challenges in the interview and recruitment process.

Factors influencing medical student choices in the integrated vascular surgery match: Implications for future post-pandemic residency matches

OBJECTIVE

Integrated vascular surgery residency is among the most competitive specialties, but little is known about the applicant perspective. The coronavirus disease 2019 outbreak impacted the 2021 integrated vascular surgery residency match because of travel restrictions. We sought to better understand pre-pandemic applicant recruitment strategies, logistics of away rotations, and the residency interview process to identify areas for improvement in the application process.

METHODS

An anonymous survey was sent to matched students in 2020, inquiring about motivations for pursuing vascular surgery (VS), logistic of away rotations and interviews, and factors influencing students' rank lists.

RESULTS

Seventy of the 73 matched students completed the survey (95.9% response rate). The median age was 27 (range, 25-41); 32.9% were female, 91.4% were U.S. medical students, and 77.1% were from institutions with a VS training program. Factors most strongly influencing the decision to choose VS as a career were interest in open vascular procedures, endovascular procedures, perceived job satisfaction, emerging technologies, and influence of a mentor. The prospect of the job market, future salary, and competitiveness of the application process had the least impact. Of the matched students, 82.9% completed an away rotation (median, 2; range, 1-4), with 51.7% of students paying a total cost of more than $2500. Fifty percent of students matched either at their home institution or where they had performed an away rotation. Students reported application submissions to a median of 50 programs (range, 1-70) and interviewed at 17 (range, 1-28), with 40% of students paying a total of more than $4000 for interview costs. The most significant factors affecting students' rank lists included program culture, open aortic surgical volume, geography, and complex endovascular procedure volume. Tours of facilities, resident salary, and male/female distribution had the least importance.

CONCLUSIONS

Successfully matched applicants in 2020 prioritized operative case volume and program collegiality when ranking programs. Despite their high cost, away rotations played an important role in the Match, suggesting that time spent at potential institutions allowed ideal assessment of factors for students. The high average number of away rotations and in-person interviews performed in 2019-2020 was limited for the 2021 Match due to coronavirus disease 2019 restrictions. Programs will have to continue developing creative alternatives or additions to away rotations and the application processes to assure continued success in future post-pandemic Match cycles.

Influence of thoracic endovascular aortic repair on true lumen helical morphology for Stanford type B dissections

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) can change the morphology of the flow lumen in aortic dissections, which may affect aortic hemodynamics and function. This study characterizes how the helical morphology of the true lumen in type B aortic dissections is altered by TEVAR.

METHODS

Patients with type B aortic dissection who underwent computed tomography angiography before and after TEVAR were retrospectively reviewed. Images were used to construct three-dimensional stereolithographic surface models of the true lumen and whole aorta using custom software. Stereolithographic models were segmented and co-registered to determine helical morphology of the true lumen with respect to the whole aorta. The true lumen region covered by the endograft was defined based on fiducial markers before and after TEVAR. The helical angle, average helical twist, peak helical twist, and cross-sectional eccentricity, area, and circumference were quantified in this region for pre- and post-TEVAR geometries.

RESULTS

Sixteen patients (61.3 ± 8.0 years; 12.5% female) were treated successfully for type B dissection (5 acute and 11 chronic) with TEVAR and scans before and after TEVAR were retrospectively obtained (follow-up interval 52 ± 91 days). From before to after TEVAR, the true lumen helical angle (-70.0 ± 71.1 to -64.9 ± 75.4°; P = .782), average helical twist (-4.1 ± 4.0 to -3.7 ± 3.8°/cm; P = .674), and peak helical twist (-13.2 ± 15.2 to -15.4 ± 14.2°/cm; P = .629) did not change. However, the true lumen helical radius (1.4 ± 0.5 to 1.0 ± 0.6 cm; P < .05) and eccentricity (0.9 ± 0.1 to 0.7 ± 0.1; P < .05) decreased, and the cross-sectional area (3.0 ± 1.1 to 5.0 ± 2.0 cm²; P < .05) and circumference (7.1 ± 1.0 to 8.0 ± 1.4 cm; P < .05) increased significantly from before to after TEVAR. The distinct bimodal distribution of chiral and achiral native dissections disappeared after TEVAR, and subgroup analyses showed that the true lumen circumference of acute dissections increased with TEVAR, although it did not for chronic dissections.

CONCLUSIONS

The unchanged helical angle and average and peak helical twists as a result of TEVAR suggest that the angular positions of the true lumen are constrained and that the endografts were helically conformable in the angular direction. The decrease of helical radius indicated a straightening of the corkscrew shape of the true lumen, and in combination with more circular and expanded lumen cross-sections, TEVAR produced luminal morphology that theoretically allows for lower flow resistance through the endografted portion. The impact of TEVAR on dissection flow lumen morphology and the interaction between endografts and aortic tissue can provide insight for improving device design, implantation technique, and long-term clinical outcomes.

Unique Complications and Failure Modes of Iliac Branch Devices

OBJECTIVES

Iliac branch devices (IBDs) are modular, bifurcated endografts designed to preserve hypogastric flow during endovascular aortoiliac aneurysm repair. We report our single center outcomes, and describe the unique complications of these devices: inability to cannulate the hypogastric artery (technical failure), occlusion of the internal branch, and type III endoleak from separation of components between the main body and IBD.

METHODS

A prospectively maintained institutional database of patients undergoing IBD implantation between 2014 and 2019 was reviewed. Technical and clinical outcomes were evaluated. We then identified patients having one of the IBD-specific complications and patient, anatomic, and procedural data were analyzed to identify factors associated with these failures.

RESULTS

Sixty-four IBDs were placed in 59 patients during the study period. Mean age was 71.2 ± 8.6, and 92% were male. A 74.6% of patients had a current or prior abdominal aortic aneurysm, and 9.4% had a hypogastric aneurysm. Technical success was achieved in 60/64 cases (93.8%); prior endovascular aortic repair was associated with technical failure (P = 0.04). There were 5 instances of component separation between the main body and the IBD: 3 occurred intraoperatively and were repaired with additional bridging components, and 2 occurred on late follow-up and required reintervention. Increased tortuosity index of both aortoiliac (1.7 ± 0.4 vs. 1.3 ± 02, P = 0.04) and iliac-specific (3.9 ± 2.4 vs. 1.9 ± 0.9, P = 0.03) segments were significantly associated with component separation, as was the use of larger internal iliac components (13.9 ± 2.4 vs. 11.1 ± 2.3 mm, P = 0.04). Internal branch occlusions occurred in 4 patients (6.7%). Two were successfully reopened with endovascular procedures, with two being asymptomatic. No specific factors were found to be predictive of branch occlusion.

CONCLUSIONS

IBD-specific complications occur rarely. History of prior endovascular aortic repair is associated with technical failure, while increased aortic and iliac tortuosity are predictive of component separation and type III endoleak. Severe tortuosity should be carefully considered when planning for IBD.

Multiaxial pulsatile dynamics of the thoracic aorta and impact of thoracic endovascular repair

•

Altered motion of the thoracic aorta after thoracic endovascular aortic repair.

•

Geometric analysis with cardiac-gated computed tomography and computer modeling.

•

Decreased motion of the stented aorta and increased motion above the stented aorta.

•

Longitudinal curvature and diametric deformation affected by presence of endograft.

Purpose

The thoracic aorta is a highly mobile organ whose dynamics are altered by thoracic endovascular aorta repair (TEVAR). The aim of this study was to quantify cardiac pulsatility-induced multi-axial deformation of the thoracic aorta before and after descending aortic TEVAR.

Methods

Eleven TEVAR patients (8 males and 3 females, age 57–89) underwent retrospective cardiac-gated CT angiography before and after TEVAR. 3D geometric models of the thoracic aorta were constructed, and lumen centerlines, inner and outer surface curves, and cross-sections were extracted to measure aortic arclength, centerline, inner surface, and outer surface longitudinal curvatures, as well as cross-sectional effective diameter and eccentricity for the ascending and stented aortic portions.

Results

From pre- to post-TEVAR, arclength deformation was increased at the ascending aorta from 5.9 ± 3.1 % to 8.8 ± 4.4 % (P < 0.05), and decreased at the stented aorta from 7.5 ± 5.1 % to 2.7 ± 2.5 % (P < 0.05). Longitudinal curvature and diametric deformations were reduced at the stented aorta. Centerline curvature, inner surface curvature, and cross-sectional eccentricity deformations were increased at the distal ascending aorta.

Conclusions

Deformations were reduced in the stented thoracic aorta after TEVAR, but increased in the ascending aorta near the aortic arch, possibly as a compensatory mechanism to maintain overall thoracic compliance in the presence of reduced deformation in the stiffened stented aorta.

Late Venous Thoracic Outlet Syndrome After Anatomic Fixation of a Diaphyseal Clavicle Fracture: A Case Report

CASE

We report the case of a 29-year-old man with a displaced mid-diaphyseal clavicle fracture that healed in anatomic position without fracture callus after surgical treatment but developed symptoms of late venous thoracic outlet syndrome (TOS) 19 months postoperatively. He was diagnosed with proximal subclavian vein thrombosis and was treated with urgent thrombolysis and staged first rib resection with resolution of symptoms.

CONCLUSIONS

Late venous TOS is a potential complication of clavicle fracture, even in the setting of anatomic reduction and primary bone healing. This entity has previously only been described in the setting of nonunion and malunion.

Patient-specific computational flow modelling for assessing hemodynamic changes following fenestrated endovascular aneurysm repair

Objective

This study aimed to develop an accessible patient-specific computational flow modelling pipeline for evaluating the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), with the hypothesis that computational flow modelling can detect aortic branch hemodynamic changes associated with fEVAR graft implantation.

Methods

Patients who underwent fEVAR for juxtarenal aortic aneurysms with the Cook ZFEN were retrospectively selected. Using open-source SimVascular software, preoperative and postoperative visceral aortic anatomy was manually segmented from computed tomography angiograms. Three-dimensional geometric models were then discretized into tetrahedral finite element meshes. Patient-specific pulsatile in-flow conditions were derived from known supraceliac aortic flow waveforms and adjusted for patient body surface area, average resting heart rate, and blood pressure. Outlet boundary conditions consisted of three-element Windkessel models approximated from physiologic flow splits. Rigid wall flow simulations were then performed on preoperative and postoperative models with the same inflow and outflow conditions. We used SimVascular's incompressible Navier-Stokes solver to perform blood flow simulations on a cluster using 72 cores.

Results

Preoperative and postoperative flow simulations were performed for 10 patients undergoing fEVAR with a total of 30 target vessels (20 renal stents, 10 mesenteric scallops). Postoperative models required a higher mean number of mesh elements to reach mesh convergence (3.2 ± 1.8 × 10⁶ vs 2.6 ± 1.1 × 10⁶; P = .005) with a longer mean computational time (10.3 ± 6.3 hours vs 7.8 ± 3.5 hours; P = .04) compared with preoperative models. fEVAR was associated with small but statistically significant increases in mean peak proximal aortic arterial pressure (140.3 ± 11.0 mm Hg vs 136.9 ± 8.7 mm Hg; P = .02) and peak renal artery pressure (131.6 ± 14.8 mm Hg vs 128.9 ± 11.8 mm Hg; P = .04) compared with preoperative simulations. No differences were observed in peak pressure in the celiac, superior mesenteric, or distal aortic arteries (P = .17-.96). When measuring blood flow, the only observed difference was an increase in peak renal flow rate after fEVAR (17.5 ± 3.8 mL/s vs 16.9 ± 3.5 mL/s; P = .04). fEVAR was not associated with changes in the mean pressure or the mean flow rate in the celiac, superior mesenteric, or renal arteries (P = .06-.98). Stenting of the renal arteries did not induce significant changes time-averaged wall shear stress in the proximal renal artery (23.4 ± 8.1 dynes/cm² vs 23.2 ± 8.4 dynes/cm²; P = .98) or distal renal artery (32.7 ± 13.9 dynes/cm² vs 29.6 ± 11.8 dynes/cm²; P = .23). In addition, computational visualization of cross-sectional velocity profiles revealed low flow disturbances associated with protrusion of renal graft fabric into the aortic lumen.

Conclusions

In a pilot study involving a selective cohort of patients who underwent uncomplicated fEVAR, patient-specific flow modelling was a feasible method for assessing the hemodynamic performance of various two-vessel fenestrated device configurations and revealed subtle differences in computationally derived peak branch pressure and blood flow rates. Structural changes in aortic flow geometry after fEVAR do not seem to affect computationally estimated renovisceral branch perfusion or wall shear stress adversely. Additional studies with invasive angiography or phase contrast magnetic resonance imaging are required to clinically validate these findings. (JVS–Vascular Science 2021;2:53-69.)

Clinical Relevance

Using a computational flow modelling for assessing the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), this real-world, patient-specific study included 10 participants and found that structural changes in aortic flow geometry after fEVAR did not seem to adversely impact estimated renal or visceral branch perfusion metrics (eg, peak and mean arterial pressure and flow rates) or wall shear stress. These findings overall support the ongoing clinical use of commercially available fEVAR devices for repair of juxtarenal aortic aneurysms, and provides a computational framework for future evaluation of fEVAR configurations in a preoperative or postoperative settings.

Molecular Imaging of Chimeric Antigen Receptor T Cells by ICOS-ImmunoPET

PURPOSE

Immunomonitoring of chimeric antigen receptor (CAR) T cells relies primarily on their quantification in the peripheral blood, which inadequately quantifies their biodistribution and activation status in the tissues. Noninvasive molecular imaging of CAR T cells by PET is a promising approach with the ability to provide spatial, temporal, and functional information. Reported strategies rely on the incorporation of reporter transgenes or ex vivo biolabeling, significantly limiting the application of CAR T-cell molecular imaging. In this study, we assessed the ability of antibody-based PET (immunoPET) to noninvasively visualize CAR T cells.

EXPERIMENTAL DESIGN

After analyzing human CAR T cells in vitro and ex vivo from patient samples to identify candidate targets for immunoPET, we employed a syngeneic, orthotopic murine tumor model of lymphoma to assess the feasibility of in vivo tracking of CAR T cells by immunoPET using the 89Zr-DFO-anti-ICOS tracer, which we have previously reported.

RESULTS

Analysis of human CD19-CAR T cells during activation identified the Inducible T-cell COStimulator (ICOS) as a potential target for immunoPET. In a preclinical tumor model, 89Zr-DFO-ICOS mAb PET-CT imaging detected significantly higher signal in specific bone marrow-containing skeletal sites of CAR T-cell-treated mice compared with controls. Importantly, administration of ICOS-targeting antibodies at tracer doses did not interfere with CAR T-cell persistence and function.

CONCLUSIONS

This study highlights the potential of ICOS-immunoPET imaging for monitoring of CAR T-cell therapy, a strategy readily applicable to both commercially available and investigational CAR T cells.See related commentary by Volpe et al., p. 911.

Contemporary Practices and Complications of Surgery for Thoracic Outlet Syndrome in the United States

BACKGROUND

Thoracic outlet syndrome (TOS) surgery is relatively rare and controversial, given the challenges in diagnosis as well as wide variation in symptomatic and functional recovery. Our aims were to measure trends in utilization of TOS surgery, complications, and mortality rates in a nationally representative cohort and compare higher versus lower volume centers.

METHODS

The National Inpatient Sample was queried using International Classification of Diseases, Ninth Revision, codes for rib resection and scalenectomy paired with axillo-subclavian aneurysm (arterial [aTOS]), subclavian deep vein thrombosis (venous [vTOS]), or brachial plexus lesions (neurogenic [nTOS]). Basic descriptive statistics, nonparametric tests for trend, and multivariable hierarchical regression models with random intercept for center were used to compare outcomes for TOS types, trends over time, and higher and lower volume hospitals, respectively.

RESULTS

There were 3,547 TOS operations (for an estimated 18,210 TOS operations nationally) performed between 2010 and 2015 (89.2% nTOS, 9.9% vTOS, and 0.9% aTOS) with annual case volume increasing significantly over time (P = 0.03). Higher volume centers (≥10 cases per year) represented 5.2% of hospitals and 37.0% of cases, and these centers achieved significantly lower overall major complication (defined as neurologic injury, arterial or venous injury, vascular graft complication, pneumothorax, hemorrhage/hematoma, or lymphatic leak) rates (adjusted odds ratio [OR] 0.71 [95% confidence interval 0.52-0.98]; P = 0.04], but no difference in neurologic complications such as brachial plexus injury (aOR 0.69 [0.20-2.43]; P = 0.56) or vascular injuries/graft complications (aOR 0.71 [0.0.33-1.54]; P = 0.39). Overall mortality was 0.6%, neurologic injury was rare (0.3%), and the proportion of patients experiencing complications decreased over time (P = 0.03). However, vTOS and aTOS had >2.5 times the odds of major complication compared with nTOS (OR 2.68 [1.88-3.82] and aOR 4.26 [1.78-10.17]; P < 0.001), and ∼10 times the odds of a vascular complication (aOR 10.37 [5.33-20.19] and aOR 12.93 [3.54-47.37]; P < 0.001], respectively. As the number of complications decreased, average hospital charges also significantly decreased over time (P < 0.001). Total hospital charges were on average higher when surgery was performed in lower volume centers (<10 cases per year) compared with higher volume centers (mean $65,634 [standard deviation 98,796] vs. $45,850 [59,285]; P < 0.001).

CONCLUSIONS

The annual number of TOS operations has increased in the United States from 2010 to 2015, whereas complications and average hospital charges have decreased. Mortality and neurologic injury remain rare. Higher volume centers delivered higher value care: less or similar operative morbidity with lower total hospital charges.

Tryptophan requirement of first-cycle commercial laying hens in peak egg production

An experiment was conducted to evaluate the digestible tryptophan (Trp) requirement of laying hens from 22 to 34 wk of age. A total of 252 Hy-line W-36 laying hens were selected at 16 wk of age and allocated by weight (P = 0.90) to 7 dietary treatments resulting in 12 replicate cages of 3 birds for each treatment. A Trp-deficient basal diet was formulated using corn, corn gluten meal, and soybean meal for each of the 3 dietary phases and supplemented with synthetic L-Trp to provide 105, 119, 133, 147, 162, 176, and 190 mg digestible Trp on a daily basis over the experimental period. To adapt the hens to experimental diets, pullets were fed complete diets that contained increasing amounts of corn gluten meal. Hens received a controlled amount of feed daily based on feed intake expected under commercial conditions. Linear and quadratic broken-line, and quadratic polynomial models were used to estimate digestible Trp requirements based on hen-housed egg production (HHEP), egg mass (EM), and feed efficiency (FE). FE was calculated using EM and feed intake. Digestible Trp requirements were estimated to be 137, 183, and 192 mg/d for HHEP; 133, 180, and 183 for EM and 133, 177, and 173 for FE using linear broken-line, quadratic broken-line, and quadratic polynomial analysis, respectively. The quadratic broken line model in this experiment resulted in the best fit (R²) for all parameters measured. Linear broken line estimates resulted in lower estimates that the other models, and HHEP resulted in higher estimated digestible Trp requirement than EM and FE.

Quantification of true lumen helical morphology and chirality in type B aortic dissections

Chirality is a fundamental property in many biological systems. Motivated by previous observations of helical aortic blood flow, aortic tissue fibers, and propagation of aortic dissections, we introduce methods to characterize helical morphology of aortic dissections. After validation on computer-generated phantoms, the methods were applied to patients with type B dissection. For this cohort, there was a distinct bimodal distribution of helical propagation of the dissection with either achiral or exclusively right-handed chirality, with no intermediate cases or left-handed cases. This clear grouping indicates that dissection propagation favors these two modes, which is potentially due to the right-handedness of helical aortic blood flow and cell orientation. The characterization of dissection chirality and quantification of helical morphology advances our understanding of dissection pathology and lays a foundation for applications in clinical research and treatment practice. For example, the chirality and magnitude of helical metrics of dissections may indicate risk of dissection progression, help define treatment and surveillance strategies, and enable development of novel devices that account for various helical morphologies.NEW & NOTEWORTHY A novel definition of helical propagation of type B aortic dissections reveals a distinct bimodality, with the true lumen being either achiral (nonhelical) or exclusively right-handed. This right-handed chirality is consistent with anatomic and physiological phenomena such as right-handed twist during left ventricle contraction, helical blood flow, and tissue fiber direction. The helical character of aortic dissections may be useful for pathology research, diagnostics, treatment selection, therapeutic durability prediction, and aortic device design.

Intraoperative heparin use is associated with reduced mortality without increasing hemorrhagic complications after thoracic endovascular aortic repair for blunt aortic injury

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) is an effective treatment of blunt thoracic aortic injury (BTAI). However, the risks and benefits of administering intraoperative heparin in trauma patients are not well-defined, especially with regard to bleeding complications.

METHODS

The Vascular Quality Initiative registry was queried from 2013 to 2019 to identify patients who had undergone TEVAR for BTAI with or without the administration of intraoperative heparin. Univariate analyses were performed with the Student t test, Fisher exact test, or χ² test, as appropriate. Multivariable logistic regression was then performed to assess the association of heparin with inpatient mortality.

RESULTS

A total of 655 patients were included, of whom most had presented with grade III (53.3%) or IV (20%) BTAI. Patients receiving heparin were less likely to have an injury severity score (ISS) of ≥15 (70.2% vs 90.5%; P < .0001) or major head or neck injury (39.6% vs 62.9%; P < .0001). Patients receiving heparin also had a lower incidence of inpatient death (5.1% vs 12.9%; P < .01). Across all injury grades, heparin use was not associated with the need for intraoperative transfusion or postoperative transfusion or the development of hematoma. In patients with grade III BTAI, the nonuse of heparin was associated with an increased risk of lower extremity embolization events (7.4% vs 1.8%; P < .05). On multivariable logistic regression analysis for inpatient mortality, intraoperative heparin use (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.11-0.86; P < .05) and female gender (OR, 0.11; 95% CI, 0.11-0.86; P < .05) were associated with better survival, even after controlling for head and neck trauma and injury grade. In contrast, increased age (OR, 1.06; 95% CI, 1.03-1.1; P < .001), postoperative transfusion (OR, 1.06; 95% CI, 1.02-1.11; P < .01), higher ISS (OR, 1.04; 95% CI, 1.01-1.07; P < .05), postoperative dysrhythmia (OR, 4.48; 95% CI, 1.10-18.18; P < .05), and postoperative stroke or transient ischemic attack (OR, 5.54; 95% CI, 1.11-27.67; P < .05) were associated with increased odds of inpatient mortality.

CONCLUSIONS

Intraoperative heparin use was associated with reduced inpatient mortality for patients undergoing TEVAR for BTAI, including those with major head or neck trauma and high ISSs. Heparin use did not increase the risk of hemorrhagic complications across all injury grades. Also, in patients with grade III BTAI, heparin use was associated with a reduced risk of lower extremity embolic events. Heparin appears to be safe during TEVAR for BTAI and should be administered when no specific contraindication exists.

Determining the 4th limiting amino acid in low crude protein diets for male and female Cobb MV × 500 broilers

1. Four experiments were conducted to determine the 4th limiting amino acid (AA) in maize-soybean meal-based diets. 2. Deletion assay methodology was used to quantify performance and carcase trait responses to potential deficiencies in essential and conditionally essential AA caused by reductions in dietary crude protein of maize-soybean meal-based diets from 202.9 to 186.5 g/kg. 3. The deletion of Val, Phe and Gly + Pro resulted in negative effects on live performance and carcase traits for male broilers, whereas AA deletion only affected wing weights for females with no response on live performance. 4. Further experimentation could not duplicate a response to Phe or Pro in male broilers. 5. Valine was identified as the potential 4th limiting AA in maize-soybean meal-based diets and was not found to be co-limiting with Ile.

Long-term chimney/snorkel endovascular aortic aneurysm repair experience for complex abdominal aortic pathologies within the PERICLES registry

OBJECTIVE

The early and short-term efficacy of the snorkel/chimney technique for endovascular aortic aneurysm repair (ch-EVAR) have been previously reported. However, long-term ch-EVAR performance, vessel patency, and patient survival remain unknown. Our study evaluated the late outcomes to identify possible predictors of failure within the PERICLES (performance of the chimney technique for the treatment of complex aortic pathologies) registry.

METHODS

Clinical and radiographic data from patients who had undergone ch-EVAR from 2008 to 2014 in the PERICLES registry were updated with an extension of the follow-up. Regression models were used to evaluate the relevant anatomic and operative characteristics as factors influencing the late results. We focused on patients with ≥30 months of follow-up (mean, 46.6 months; range, 30-120 months).

RESULTS

A total of 517 patients from the initial PERICLES registry were included in the present analysis, from which the mean follow-up was updated from 17.1 months to 28.2 months (range, 1-120 months). All-cause mortality at the latest follow-up was 25.5% (n = 132), with an estimated patient survival of 87.6%, 74.4%, and 66.1% at 1, 3, and 5 years, respectively. A subgroup of 244 patients with 387 chimney grafts placed (335 renal arteries, 42 superior mesenteric arteries, 10 celiac arteries) and follow-up for ≥30 months was used to analyze specific anatomic and device predictors of adverse events. In the subgroup, the technical success was 88.9%, and the primary patency was 94%, 92.8%, 92%, and 90.5% at 2.5, 3, 4, and 5 years, respectively. The mean aneurysm sac regression was 7.8 ± 11.4 mm (P < .0001). Chimney graft occlusion had occurred in 24 target vessels (6.2%). Late open conversion was required in 5 patients for endograft infection in 2, persistent type Ia endoleak in 2, and endotension in 1 patient. The absence of an infrarenal neck (odds ratio, 2.86; 95% confidence interval, 1.32-6.19; P = .007) was significantly associated with long-term device-related complications. A sealing zone diameter >30 mm was significantly associated with persistent or late type Ia endoleak (odds ratio, 4.86; 95% confidence interval, 1.42-16.59; P = .012).

CONCLUSIONS

The present analysis of the PERICLES registry has provided the missing long-term experience for the ch-EVAR technique, showing favorable results with more than one half of the patients surviving for >5 years and a chimney graft branch vessel patency of 92%. The absence of an infrarenal neck and treatment with a sealing zone diameter >30 mm were the main anatomic long-term limits of the technique, requiring adequate preoperative planning and determination of the appropriate indication.

Renal Stent Complications and Impact on Renal Function after Standard Fenestrated Endovascular Aneurysm Repair

BACKGROUND

To report renal outcomes including long-term patency, secondary interventions, and related renal function after fenestrated endovascular aortic repair (fEVAR).

METHODS

Single-center retrospective review of patients undergoing fEVAR between 2012 and 2018 using the Cook ZFEN device. Renal stent complications, defined as any stenosis, occlusion, kink, renal stent-related endoleak, and reinterventions were tabulated. Estimated glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease formula.

RESULTS

During the study period, 114 patients underwent elective fEVAR. Of 329 total target vessels, 193 renal arteries were stented (133 Atrium iCAST, 60 Gore VBX). Technical success was achieved in 97.4%, and the mean follow-up was 23.3 months. Seventeen renal complications occurred in 14 patients (12.3%), including 4 occlusions, 9 stenosis, 3 dislocations, and 1 type III endoleak. All stent complications underwent endovascular reintervention with a median hospital stay of 1 day (0-10) and a technical success of 94.2%. One patient suffered renal hemorrhage that warranted embolization. Patients with occlusion were treated the day of diagnosis, and mean time from diagnosis to intervention for stenosis was 21.5 days. Estimated primary patency was 92.1 % and 81.5% at 24 and 48 months, respectively. On multivariate analysis, larger native renal artery diameter was the only independent protective factor against patency loss (HR 0.23 (0.09-0.59)). Secondary patency at latest follow-up was 99.4%. Mean eGFR was not significantly different at latest follow-up between patients with renal complications versus those without (43.75 vs. 55.58 mL/min/1.73 m², P = 0.09). Comparing patients with and without renal stent complications, 81.4% and 72.7% of patients had stable or improved renal disease by chronic kidney disease staging compared with baseline (P = 0.51).

CONCLUSIONS

fEVAR is a durable option for the treatment of juxtarenal aortic aneurysms and is associated with excellent secondary patency. Renal stent complications have no significant impact on renal function, but smaller native renal arteries are at higher risk of stent-graft complications.

Paclitaxel exposure and long-term mortality of patients treated with the Zilver PTX drug-eluting stent

OBJECTIVES

Paclitaxel-eluting stents have demonstrated improved patency over balloon angioplasty and bare metal stenting for endovascular interventions in the femoral-popliteal segment. Recently, concerns have arisen regarding the safety of paclitaxel use and its association with mortality. This study aims to examine real-world, long-term mortality, and patency of patients treated with the Zilver PTX drug-eluting stent.

METHODS

Patients treated with the PTX stent after FDA approval between 2013 and 2015 were identified from an institutional database. Demographic, procedural, and device information was collected and initial- and lifetime-exposure dose of paclitaxel was calculated. The primary outcome was all-cause mortality and its association with paclitaxel exposure. Long-term patency was also evaluated.

RESULTS

Seventy-nine procedures involving PTX placement were performed on 64 individual patients during the study period, with 15 (23.4%) having bilateral procedures. Average age was 70 years, and 71.9% were male. Forty-five patients (70.3%) were claudicants, and 19 (29.7%) had chronic, limb-threatening ischemia. An average of 2.3 PTX stents, totaling 203 mm in length, were placed per procedure. Paclitaxel exposure was 1.87 mg/procedure initially (range 0.38-4.03 mg), and average lifetime exposure was 4.65 mg/patient (range 0.38-27.91 mg). Average follow-up was 59.6 months. Kaplan-Meier estimated survival was 96.9%, 81.2% and 71.7% at one , three, and five years. On multivariate analysis, no specific factors were associated with overall morality including initial paclitaxel dose (HR 0.99, 95% CI 0.99-1.00) and lifetime paclitaxel exposure (HR 0.98, 95% CI 0.89-1.08). Kaplan-Meier primary patency was 76.2%, 60.1%, and 29.3% at one, two, and five years, respectively. Secondary patency was 92.2%, 85.4%, and 75.2% at the same intervals.

CONCLUSIONS

At a mean follow-up of five years, exposure to higher doses of paclitaxel from Zilver PTX does not appear to be associated with increased mortality compared to lower doses in real-world patients. Long-term patency rates confirm the efficacy of Zilver PTX, and further investigation may be warranted before abandoning paclitaxel use altogether.

Mid-Term Survival after Thoracic Endovascular Aortic Repair by Indication in the Medicare Population

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) is indicated for treatment of aneurysms, dissections, and traumatic injury. We describe mid-term mortality and reintervention rates in Medicare beneficiaries undergoing TEVAR.

STUDY DESIGN

Patients who underwent TEVAR between 2006 and 2014 were identified by CPT codes in a 20% Medicare sample. Indication for aortic repair (aneurysm, dissection, trauma) was ascertained via ICD-9 codes. Follow-up was evaluated until 2015. Kaplan-Meier survival analysis and Cox regression were used to compare mortality, with reintervention and mortality rates expressed as a composite outcome in a hazard ratio with 95% confidence interval (hazard ratio [HR] 95% CI).

RESULTS

There were 3,095 patients who underwent TEVAR during the study period: 1,465 (47%) for aneurysm, 1,448 (47%) for dissection, and 182 (5.9%) for trauma. Mean patient age was 74.4 years, and 44.5% were female. Median follow-up was 2.7 years. The overall 30-day, 1-year, and 5-year, and 8-year survival rates were 93%, 78%, 49%, and 33%, respectively. Thirty-day mortality was highest in traumatic indications, but overall mortality was highest in patients undergoing TEVAR for aneurysm. Freedom from combined reintervention and mortality at 30 days, 1 year, 5 years, and 8 years was 89%, 73%, 43%, and 29%, respectively. Reintervention was highest in patients undergoing TEVAR for dissection (12.8%), followed by aneurysm (10.0%) and trauma (5.5%). Advanced age (HR 1.03 per year, 95% CI 1.02-1.03), congestive heart failure (CHF) (HR 1.48, 95% CI 1.33-1.65), dementia (HR 1.40, 95% CI 1.14-1.28), and rupture (HR 1.38, 95% CI 1.24-1.54) were associated with mortality.

CONCLUSIONS

Midterm survival is lower in patients who undergo TEVAR for dissection and aneurysm compared with trauma. Aneurysmal disease, advanced age, CHF, dementia, and aortic rupture are associated with mortality and reintervention in TEVAR.

Increased vertebral exposure in anterior lumbar interbody fusion associated with venous injury and deep venous thrombosis

BACKGROUND

Published outcomes on anterior lumbar interbody fusion (ALIF) have focused on 1-2 level fusion with and without vascular surgery assistance. We examined the influence of multilevel fusion on exposure-related outcomes when performed by vascular surgeons.

METHODS

We retrospectively reviewed clinical and radiographic data for patients undergoing anterior lumbar interbody fusion (ALIF) with exposure performed by vascular surgeons at a single practice.

RESULTS

From 2017-2018, 201 consecutive patients underwent vascular-assisted ALIF. Patients were divided by number of vertebral levels exposed (90 patients with 1 level exposed, 71 with 2, 40 with 3+). Demographically, 3+ level fusion patients were older (P=.0045) and more likely to have had prior ALIF (P=.0383). Increased vertebral exposure was associated with higher rates of venous injury (P=.0251), increased procedural time (P= .0116), length of stay (P=.0001), and incidence of postoperative DVT (P=.0032). There was a 6.5% rate of intraoperative vascular injury, comprised of 3 major and 10 minor venous injuries. In patients who experienced complications, 92.3% of injuries were repaired primarily. 23% of patients with venous injuries developed postoperative deep venous thrombosis. In a multivariate logistic regression model, increased levels of exposure (RR = 6.23, P = .026) and a history of degenerative spinal disease (RR = .033, P = .033) were predictive of intraoperative venous injury.

CONCLUSIONS

Increased vertebral exposure in anterior lumbar interbody fusion is associated with increased risk of intraoperative venous injury and postoperative deep venous thrombosis, with subsequently greater lengths of procedure time and length of stay. Rates of arterial and sympathetic injury were not affected by exposure extent.