Worldwide, more than 4 million patients with end-stage kidney disease require hemodialysis through an arteriovenous fistula (AVF). AVFs fail because of venous neointimal hyperplasia (VNH) resulting in venous stenosis formation. A phase 1 randomized trial in patients undergoing upper extremity AVF placement was performed to evaluate the safety and efficacy of autologous adipose–derived mesenchymal stem cells (MSCs) in improving AVF function. The mechanism of action by which MSCs exert their beneficial effects was investigated using AVFs created in mice and pigs treated with allogenic MSCs and xenotransplant using patient MSCs in CD1- Foxn1nu mice. At a median follow-up of 42 months, patients with MSC-treated AVFs had reduced time to maturation with an increase in the vein diameter compared with controls. AVFs treated with allogenic MSCs in mice and pigs had an increase in M2- and M1-like macrophages with a decrease in VNH. Transcriptomic analysis of AVFs treated with allogenic MSCs in mouse and MSC xenotransplants of patients with successful AVFs showed decreased peroxisome proliferator–activated receptor gamma ( Ppar γ) and leptin receptor ( Lepr ) and increased latent transforming growth factor–beta–binding protein 2 ( Ltbp2 ). PPARγ was reduced in CD68 (+) cells from successful AVFs and allogenic MSC-treated mouse AVFs. Venous stenosis and VNH formation were mitigated in AVFs of mice with Ppar γ ablation in immune cells. Conditioned medium from MSCs of responders versus nonresponders had decreased proinflammatory genes, senescence-associated proteins, and monocyte-to-macrophage differentiation induced by phorbol 12-myristate-13-acetate. Periadventitial delivery of MSCs to AVFs promoted positive vascular remodeling through decreased inflammatory responses.
Treatment Trends and Outcomes of Endovascular versus Open Thoracoabdominal Aortic Aneurysm Repair – A Single-center Comparative Cohort Study
Objective: To evaluate treatment trends and compare outcomes following fenestrated-branched endovascular aortic repair (FB-EVAR) versus open surgical repair (OSR) of thoracoabdominal aortic aneurysms (TAAA). Background: FB-EVAR has been increasingly utilized as a less invasive alternative to OSR for treatment of TAAAs. Methods: We studied patients who underwent elective FB-EVAR or OSR of TAAAs (2008-2020), since the initiation of an Advanced Endovascular Aortic Program. Primary endpoints were early major adverse events (MAE) and early and late all-cause mortality. Propensity score overlap weighting analysis was performed to adjust for measured confounders between groups. Results: There were 357 (70.8%) patients treated by FB-EVAR and 147 (29.2%) with OSR. The use of FB-EVAR increased from 16.7% in 2008 to >80% since 2017 ( P <0.001). Incidences of early MAEs were 25.8% and 49.0%, respectively; early mortality rates for FB-EVAR and OSR were 2.5% and 6.8%, respectively. In the weighted cohort, FB-EVAR patients had decreased early MAEs (weight-adjusted odds ratio [aOR], 0.28; 95% confidence interval [CI], 0.18-0.41; P <0.001) and mortality (aOR, 0.35; 95% CI, 0.17-0.73; P =0.005) versus OSR patients. Five-year survival estimates were 52.2% (95% CI, 45.2-60.4%) and 78.0% (95% CI, 70.6-86.2%), respectively. In the weighted cohort, there was no significant difference in late survival between groups (weight-adjusted hazard ratio, 1.33; 95% CI, 0.74-2.39; P =0.34). Conclusions: This study confirmed the change in practice from OSR to FB-EVAR for treatment of TAAAs over the past decade. Incidences of early MAEs and mortality were lower with FB-EVAR, with no significant difference in late survival in the weighted cohort.
Target Artery Outcomes Following Endovascular Versus Open Surgical Repair of Thoracoabdominal Aortic Aneurysms
Objective: To compare target artery (TA) outcomes after fenestrated or branched endovascular aortic repair (FB-EVAR) versus open surgical repair (OSR) of thoracoabdominal aortic aneurysms (TAAAs). Background: Few studies have compared TA outcomes after endovascular incorporation and open reconstruction. Methods: Among consecutive patients who underwent elective OSR or FB-EVAR of TAAAs (2008–2020), we reviewed those who had postoperative imaging studies evaluating TA. Data of FB-EVAR patients were obtained from a prospectively maintained institutional database. TAs included celiac, superior mesenteric, right, and left renal arteries treated during TAAA repairs. The primary endpoint was TA patency (primary and secondary). Results: There were 131 patients (487 TAs) treated by OSR and 350 (1300 TAs) by FB-EVAR. In the OSR group, 440 TAs (90.3%) were reconstructed by bypasses, and 47 (9.7%) by reimplantation. In the FB-EVAR group, 841 TAs (64.7%) were incorporated by fenestrations and 459 (35.3%) by directional branches. Thirty-day TA primary patency rates were not significantly different between FB-EVAR and OSR (99.4%% vs 99.0%, P = 0.36), but the secondary patency rate was higher after FB-EVAR (99.8% vs 99.0%, P = 0.02). Three-year primary patency rates were 95.9% (95% CI: 94.7%–97.2%) and 94.7% (95% CI: 92.2%–97.2%), respectively; secondary patency rates were 98.5% (95% CI: 97.7%–99.2%) and 94.7% (95% CI: 95.7%–99.2%), respectively. There were no significant differences in late primary patency and secondary patency between groups (each P < 0.05). Conclusions: TA primary and secondary patency rates following elective OSR or FB-EVAR were high. Endovascular repair was not associated with loss of primary patency and late secondary patency.
Outcomes of Visceral Arterial Interposition Graft Reconstruction for Locally Advanced Pancreatic Cancer
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.
An Analysis of Malpractice Litigation of Vascular Surgeons in Cases Involving Aortic Pathologies
Objective The aim of this study was to analyze malpractice claims for aortic pathologies and to assess if there has been a change in rate of malpractice lawsuits with evolution of endovascular therapy. Methods Malpractice lawsuits were individually screened and compiled from the Westlaw database from 2000 to 2017 through use of relevant search terms. Data were collected of allegations, diagnoses, and outcomes of each case and compared. Results 268 unique cases were included in this study, with aneurysms (54%, n = 145) and dissection (35%, n = 94) making up the majority. There was a defendant verdict in 53% (n = 141), plaintiff verdict in 24% (n = 65), and settlements in 23% (n = 62) of lawsuits. Litigation was higher in the Midwest and Northeast. There was a gradual decline in litigation overall, however endovascular case numbers remained constant. There was negligible difference in the primary allegation underlying the litigation for various aortic pathologies, time to litigation and award between open and endovascular procedures. Conclusion The proportion of litigation for clinical negligence in endovascular cases amongst all vascular surgical lawsuits is increasing. As novel methods of endovascular therapy emerge, it is imperative that physicians remain vigilant to legal considerations to minimize malpractice risk.
Impact of Shunting Practice Patterns During Carotid Endarterectomy for Symptomatic Carotid Stenosis
Background: We aimed to assess the effect of surgeons’ shunting practice and shunt use on the early outcomes of carotid endarterectomy (CEA) in recently symptomatic patients. Methods: We conducted a retrospective observational study based on a multicenter national prospective database. The Vascular Quality Initiative database (2010–2019) was queried for CEAs performed within 14 days after an ipsilateral stroke or transient ischemic attack. Surgeons were gauged as routine shunters if they shunted in >95% of CEAs, otherwise were classified as selective shunters. In-hospital stroke and death rates were compared between routine and selective shunters, stratifying by type of index event (transient ischemic attack versus stroke) and timing of CEA (≤2 versus >2 days). Results: Thirteen thousand four hundred sixty-nine CEAs were performed after a transient ischemic attack (43%) or stroke (57%), 3186 (24%) by routine shunters, and 10 283 (76%) by selective shunters. Comparing routine and selective shunters, in-hospital stroke (1.9% versus 2.4%; P =0.09) and death (0.4% versus 0.5%; P =0.73) rates were similar. A lower stroke rate (1.5% versus 4.2%; P =0.02) was achieved by routine shunters for CEA performed <2 days after an ischemic stroke. Among selective shunters, a higher stroke rate occurred in case of shunt use (2.9% versus 2.3%; P <0.01), mainly due to cases presenting with stroke (3.5% versus 2.4%; P <0.01) but not transient ischemic attack (1.8% versus 1.5%; P =0.57). Awake anesthesia was adopted in 7.8% of cases by selective shunters and in 0.8% by routine shunters, without impact on the perioperative stroke rate (1.8% versus 2.3%; P =0.349). Conclusions: In this large national cohort, the overall outcomes of CEA were similar between routine and selective shunters. A lower postoperative stroke rate was achieved by routine shunters in CEA performed <2 days after an ischemic stroke. Among selective shunters, intraoperatively indicated shunting determined an increased stroke rate, likely due to intraoperative hypoperfusion. These data may guide the decision regarding timing of CEA and shunting intention in symptomatic patients.
Outcomes of the Gore Excluder Iliac Branch Endoprosthesis Using Division Branches of the Internal Iliac Artery as Distal Landing Zones
Purpose: To evaluate the outcomes of the Gore Excluder Iliac Branch Endoprosthesis (IBE) using division branches of the internal iliac artery (IIA) as distal landing zones. Materials and Methods: Between January 1, 2014, and December 31, 2018, 74 patients (mean age 74±7 years; 72 men) treated for aortoiliac or common iliac artery aneurysms had an IBE deployed with distal landing of the side branch within the main trunk (n=60) of the internal iliac artery (IIA) vs within a division branch (n=25). Thirteen (17%) patients received bilateral IBE implantations for a total of 85 vessels evaluated. Early endpoints were technical success, 30-day mortality, 30-day major adverse events (MAEs), and 30-day major access complications. Late endpoints were survival, primary and secondary IIA patency, freedom from IIA branch instability, freedom from new-onset buttock claudication, and aneurysm sac diameter changes. Time-dependent outcomes were reported as Kaplan-Meier curves with differences assessed using the log-rank test. Estimates are presented with the 95% confidence interval (CI). Results: The overall technical success rate was 97%, with 1 technical failure per group (p=0.43). Two patients, one from each group, died within 30 days (p=0.43). No significant differences were seen in the rates of 30-day MAEs (7% vs 17%, p=0.35) or major access complications (9% vs 11%, p>0.99) for patients receiving distal landing in the main trunk vs a division branch, respectively. The mean follow-up for the entire cohort was 19±12 months. The overall 1-year survival rate was 94% (95% CI 74% to 99%). The primary and secondary patency rates at 1 year were 98% (95% CI 88% to 99%) vs 95% (95% CI 72% to 99%, p=0.72) and 98% (95% CI 88% to 99%) vs 100% (p=0.41) for the main trunk vs division branch groups, respectively. Freedom from IIA branch instability estimates were also similar at 1-year follow-up [93% (95% CI 82% to 97%) vs 90% (95% CI 66% to 97%), p=0.29], as were the freedom from new-onset buttock claudication estimates [98% (95% CI 86% to 99%) and 94% (95% CI 67% to 99%), respectively; p=0.62]. Mean sac diameter change was 5.4±5.3 mm, not significantly different between the groups (p=0.85). Conclusion: Use of the posterior or anterior division of the IIA as a distal landing zone for the Gore Excluder IBE was safe and efficacious in the midterm. This technique may permit extending indications for endovascular repair of aortoiliac aneurysms to cases with unsuitable anatomy within the IIA main trunk. Long-term assessment is needed to affirm the efficacy of this technique.