Unique characteristics of the type B aortic dissection patients with malperfusion in the Vascular Quality Initiative.

OBJECTIVE: Type B aortic dissection (TBAD) complicated by malperfusion carries high morbidity and mortality. The present study was undertaken to compare the characteristics of malperfusion and uncomplicated cohorts and to evaluate the long-term differences in survival using a granular, national registry. METHODS: Patients with TBAD entered into the thoracic endovascular aortic repair/complex endovascular aortic repair module of the Vascular Quality Initiative from 2010 to 2019 were included. The demographic, radiographic, operative, postoperative, in-hospital, and long-term reintervention data were compared between the malperfusion and uncomplicated TBAD groups using t tests and χ2 analysis, as appropriate. Overall survival was compared using Cox regression to generate survival curves. RESULTS: Of the 2820 included patients, 2267 had uncomplicated TBAD and 553 had malperfusion. The patients with malperfusion were younger (age, 55.8 vs 61.2 years; P < .001), were more often male (79.7% vs 68.1%; P < .001), had a higher preoperative creatinine (1.8 vs 1.1 mg/dL; P < .001), had more often presented with an American Society of Anesthesiologists class of 4 or 5 (81.9% vs 58.4%; P < .001), and had more often presented with urgent status (77.4% vs 32.8%; P < .001). In contrast, the uncomplicated TBAD group had had more medical comorbidities, including coronary artery disease and chronic obstructive pulmonary disease, and a larger aortic diameter (4.0 cm vs 4.9 cm; P < .001). The malperfusion group more frequently had proximal zones of disease in zones 0 to 2 (38.6% vs 31.5%; P = .002) and distal zones of disease in zones 9 and above (78.7% vs 46.2%; P < .001), with a greater number of aortic zones traversed (7.7 vs 5.1; P < .001) and a greater frequency of dissection extension into branch vessels (61.8% vs 23.1%; P < .001). Patients with malperfusion also exhibited greater case complexity, with a greater need for branch vessel stenting and longer procedure times. The overall incidence of postoperative complications was greater in the malperfusion group (39.4% vs 17.1%; P < .001) and included a greater rate of spinal cord ischemia (6.3% vs 2.2%; P < .001), acute kidney injury (10.4% vs 0.9%; P < .001), and in-hospital mortality (11.6% vs 5.6%; P < .001). In-hospital reintervention was also greater for the malperfusion patients (14.5% vs 7.4%; P < .001), although the incidence of long-term reinterventions was similar between the two groups (8.7% vs 9.7%; P = .548). A proximal zone of disease in zone 0 to 2 was associated with decreased survival. In contrast, a distal zone of disease in 9 and above, in-hospital reintervention, and long-term follow-up were associated with increased survival. Despite these differences, long-term survival did not differ between the malperfusion and uncomplicated groups (P = .320.) CONCLUSIONS: Patients presenting with TBAD and malperfusion represent a unique cohort. Despite the greater need for branch vessel stenting and in-hospital reintervention, they had similar long-term reintervention rates and survival compared with those with uncomplicated TBAD. These data lend insight with regard to the observed differences between uncomplicated and malperfusion TBAD.

Effects of dual antiplatelet therapy on graft patency after lower extremity bypass.

OBJECTIVE: Current guidelines recommend single-agent antiplatelet therapy for patients with symptomatic peripheral artery disease and consideration of dual antiplatelet therapy (DAPT) after surgical revascularization. The objective of this study was both to explore prescribing patterns of single antiplatelet therapy vs DAPT after lower extremity bypass surgery and to investigate the effects of antiplatelet therapy on bypass graft patency. METHODS: A retrospective analysis of prospectively collected nonemergent infrainguinal lower extremity bypass operations entered in the national Vascular Quality Initiative (2003-2018) with captured long-term follow-up was performed. Patients discharged on aspirin monotherapy or DAPT were identified. Linear regression investigated temporal trends in antiplatelet use. Multivariable Cox regression investigated predictors of primary, primary assisted, and secondary patency. RESULTS: Of the 13,020 patients investigated, 52.2% were discharged on aspirin monotherapy and 47.8% on DAPT. The proportion of patients discharged on DAPT increased from 10.6% in 2003 to 60.6% in 2018 (P < .001). The DAPT cohort was younger, had higher rates of medical (hypertension, diabetes, congestive heart failure, chronic obstructive pulmonary disease) and atherosclerotic (coronary artery disease, prior coronary artery bypass graft or percutaneous coronary intervention, prior lower extremity intervention) comorbidities, and had higher risk bypass procedures (more distal targets, prior inflow bypass procedure, prosthetic conduit use). Multivariable Cox regression analysis did not show any difference between the DAPT and aspirin cohorts in primary patency (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.88-1.10; P = .78), primary assisted patency (HR, 0.93; 95% CI, 0.80-1.07; P = .30), or secondary patency (HR, 0.88; 95% CI, 0.74-1.06; P = .18). On subgroup analysis based on bypass conduit, DAPT was found to have a protective effect on patency only in the prosthetic bypass cohort (primary patency: HR, 0.81 [95% CI, 0.66-1.00; P = .05]; primary assisted patency: HR, 0.74 [95% CI, 0.58-0.94; P = .01]; and secondary patency: HR, 0.60 [95% CI, 0.44-0.82; P < .001]). No patency differences were observed on adjusted subgroup analysis for the other bypass conduits. CONCLUSIONS: A significant and increasing proportion of patients are discharged on DAPT after lower extremity bypass revascularization. These patients represent a higher risk cohort with more medical comorbidities and higher risk bypass features. After controlling for these differences, DAPT therapy had no beneficial effect on overall bypass graft patency or major adverse limb events. However, on subgroup analysis, DAPT was associated with improved bypass graft patency in patients receiving prosthetic bypass conduits. Further study is warranted to investigate optimal duration of DAPT therapy and its possible bleeding complications in prosthetic bypass patients.

The evolution of open abdominal aortic aneurysm repair at a tertiary care center.

BACKGROUND: The characteristics of and indications for open abdominal aortic aneurysm (AAA) repair have evolved over time. We evaluated these trends through the experience at a tertiary care academic center. METHODS: A retrospective review was conducted for patients undergoing open AAA repair (inclusive of type IV thoracoabdominal aortic aneurysms) from 2005 to 2018 at an academic institution. Trends over time were evaluated using the Spearman test; Cox regression was used to determine predictors of mortality and to generate adjusted survival curves. RESULTS: There were 628 patients (71.5% male; 88.2% white) with a mean age of 70.5 ± 9.4 years who underwent open AAA repair with a mean aneurysm diameter of 6.2 ± 1.5 cm. The median length of stay was 10 days, and the median intensive care unit length of stay was 3 days. Urgent repair was undertaken in 21.1%; 22.3% were type IV thoracoabdominal aortic aneurysm repairs, and 9.9% were performed for explantation. Our series favored a retroperitoneal approach in the majority of cases (82.5%). The proximal clamp sites were supraceliac (46.1%), suprarenal (29.1%), and infrarenal (24.8%), with approximately a third requiring renal artery reimplantation. The average cross-clamp time was 25.5 ± 14.9 minutes; the mean renal ischemia time for supraceliac and suprarenal clamp sites was 28.4 ± 12.3 minutes and 23.5 ± 12.7 minutes, respectively. Postoperative renal dysfunction occurred in 19.6% of the overall cohort, with 6.2% requiring hemodialysis. Of those requiring postoperative hemodialysis, the majority (75%) received an urgent repair. The in-hospital mortality was 2.3% for elective cases vs 20.9% for urgent repair, and 29.8% of patients were discharged to rehabilitation, with an overall 30-day readmission rate of 7.9%. Over time, there were trends of increased aneurysm repair complexity, with decreasing infrarenal clamp sites, increasing supraceliac clamp sites, increasing proportion of explantations, and increasing need for bifurcated grafts. The acuity of aneurysm repair likewise changed, with the proportion of urgent repairs increasing over time, largely attributable to the rise in explantations. Clamp site influenced the frequency of perioperative complications. Urgent repairs and age at operation were associated with mortality, whereas mortality was not associated with need for explantation and clamp location. CONCLUSIONS: Aneurysm repair reflected increasing complexity over time, with the need for explantation among urgent repairs significantly on the rise. Urgency and clamp location independently predicted long-term mortality, even after adjustment for age. These findings underscore the changing landscape of open AAA repair in the current era.

The use of intravascular ultrasound in the treatment of type B aortic dissection with thoracic endovascular aneurysm repair is associated with improved long-term survival.

OBJECTIVE: Intravascular ultrasound (IVUS) examination is an integral technique used for treating type B aortic dissection (TBAD) because it verifies true lumen access. The purpose of this study was to evaluate the use of IVUS, to determine factors associated with IVUS use, and to investigate the potential survival benefit associated with IVUS in the treatment of TBAD. METHODS: A retrospective review of TEVARs performed for TBAD in the national Vascular Quality Initiative was performed from January 2010 to August 2018. Data collected included demographics, intraoperative and postoperative variables, and long-term mortality. Multivariable logistic regression evaluated variables associated with IVUS the use and mortality, and Cox regression was performed for adjusted survival analysis. RESULTS: In this study of 2686 patients, the average age was 60.4 years, 69.3% were male, and IVUS examination was used in 74.6% of cases. IVUS patients were younger (60.0 years vs 61.7 years; P = .004), more often male (72.1% vs 61.3%; P < .001), exhibited less coronary disease, but had higher preoperative creatinine (1.27 ± 0.89 mg/dL vs 1.14 ± 0.68 mg/dL; P < .001) and were more often treated in the acute setting (55.2% vs 49.7%; P = .03). Interestingly, there were no differences in contrast use (117.4 ± 77.6 mL vs 123.0 ± 81.90.1 mL; P = .11) or fluoroscopy time (20.3 ± 16.5 minutes vs 19.0 ± 22.1 minutes; P = .10). However, IVUS cases had a greater number of devices implanted (1.84 vs 1.65; P < .001), higher rates of Zone 0 to 2 proximal seal (43.9% vs 30.7%; P < .001), higher rates of distal seal zones beyond the diaphragm (53.9% vs 37.4%; P = .001), and larger proximal and distal graft diameters, with no differences in postoperative renal function. IVUS patients notably also had higher rates of follow-up imaging (61.3% vs 54.8%; P = .003), larger maximum aortic diameters at follow-up, and more reinterventions over time. The number of aortic devices (odds ratio [OR] 1.56; 95% confidence interval [CI], 1.24-1.97; P < .001), malperfusion indication (OR, 1.68; 95% CI, 1.17-2.42; P = .005) and distal seal zone beyond the diaphragm (OR, 1.64; 95% CI, 1.30-2.07; P < .001) were independently associated with IVUS use, whereas female gender showed a trend towards less IVUS use (OR, 0.79; 95% CI, 0.62-1.01; P = .063). Even after controlling for age, preoperative comorbidities, and postoperative complications like spinal cord ischemia, IVUS was associated with a 61% decrease in the odds of mortality (OR, 0.39; 95% CI, 0.20-0.78; P = .008), with a clear survival advantage shown in adjusted survival curves. CONCLUSIONS: IVUS examination was used in the majority of TBAD, although not universally. IVUS examination was used more often in acute TBAD and more complex aortic repairs, and was independently associated with improved long-term survival. Further study is needed to understand these patterns.

Contained rupture of arch aneurysm managed with total arch, frozen elephant trunk and endograft.

We here describe a complex case of a 75-year-old man presenting with contained rupture of an aortic arch aneurysm in the presence of a second thoracic aortic aneurysm. He was managed with emergent total arch replacement with frozen elephant trunk. Another stent-graft was used to achieve hemostasis at the distal anastomosis. He later underwent TEVAR extension to manage his second aneurysm in a staged fashion. This case demonstrates a number of important concepts in the evolving interaction between open and endovascular therapies of the aortic arch, particularly in the emergent setting.

Contained rupture of arch aneurysm managed with total arch, frozen elephant trunk and endograft.

We here describe a complex case of a 75-year-old man presenting with contained rupture of an aortic arch aneurysm in the presence of a second thoracic aortic aneurysm. He was managed with emergent total arch replacement with frozen elephant trunk. Another stent-graft was used to achieve hemostasis at the distal anastomosis. He later underwent TEVAR extension to manage his second aneurysm in a staged fashion. This case demonstrates a number of important concepts in the evolving interaction between open and endovascular therapies of the aortic arch, particularly in the emergent setting.

Trends in inferior vena cava filter placement and retrieval at a tertiary care institution.

OBJECTIVE: The aim of this study was to examine practice patterns of inferior vena cava (IVC) filter insertion and retrieval at a tertiary care institution. METHODS: A retrospective review of all IVC filter procedures performed at the University of Pennsylvania and entered into the Penn cohort of the Vascular Quality Initiative registry between January 2013 and September 2017 was performed. Data collected included demographics, venous thromboembolism risk factors, indications for filter placement, and presence and timing of retrieval. Trend analysis and multivariable logistic regression were performed to evaluate factors associated with failure to retrieve the filter. RESULTS: During the study period, 627 IVC filters were inserted. The mean age was 52.8 ± 16.9 years, and 49.3% were male; 39.2% were placed for a major indication, whereas 58.1% were placed for prophylaxis. There was a significant decline in overall frequency of filter placement during the period observed, with a 33% decrease from 2015 to 2016 and a 26% decrease from 2016 to 2017 (P < .001), with an overall retrieval rate of 44.9%. In contrast, there was a corresponding increase in filter retrieval, with a 20% increase in 2015 and a 68% increase in 2016 (P = .02). In evaluating trends separated by indication, there was a significant decline in prophylactic filter placement (P < .001) and a trend toward an increase in retrieval of prophylactic filters (P = .09). Whereas there was not a significant change in number of filter insertions for major indication (P = .06), filter retrievals for major indication filters increased (P = .01). Multivariable regression analysis revealed that longer time to follow-up (odds ratio [OR], 1.08; P < .001) and discharge to rehabilitation facility (OR, 6.14; P < .001) were predictive of failure to retrieve the filter. In contrast, filter placement at a later date within our study period (OR, 0.90; P < .001) and prophylactic indication for filter placement (OR, 0.36; P < .001) were protective from filter nonretrieval. CONCLUSIONS: These results show both a decline in overall IVC filter placement and an increase in overall IVC filter retrieval at our institution. These trends are predominantly due to a decrease in prophylactic filter placement as well as an overall increase in filter retrieval. Further study should be dedicated to increasing the retrieval rate in this population of patients.

Length of Stay after Thoracic Endovascular Aortic Repair Depends on Indication and Acuity.

BACKGROUND: Length of stay (LOS) is a commonly used metric to optimize value in medical care. Although pathways have been developed for some procedures in vascular surgery to reduce LOS, they do not yet exist for thoracic endovascular aortic repair (TEVAR). The purpose of this study is to identify and define the risk factors for prolonged LOS in patients undergoing TEVAR to facilitate pathway development. METHODS: We included TEVAR patients in the National Surgical Quality Improvement Program database from 2005 to 2015. Prolonged LOS was defined as LOS > 75th percentile of the overall cohort (11 days). Because initial analysis revealed the distinct clinical differences between dissection and aneurysm patients, further analysis was stratified by aortic pathology. Student's t-test and Chi-square tests were used to compare demographic and perioperative variables between dissection and aneurysm patients, respectively. Multivariable logistic regression was used to evaluate the predictors for prolonged LOS. RESULTS: A total of 3,021 patients underwent TEVAR, with 858 patients (28.4%) undergoing TEVAR for dissection and 2,163 (71.6%) undergoing TEVAR for aneurysm. An initial analysis with logistic regression identified dissection indication (odds ratio [OR], 2.87; 95% confidence interval [CI], 1.1-7.3) as an independent predictor of prolonged LOS. Further analysis for prolonged LOS was subsequently performed separating dissection and aneurysm patients. Aneurysm patients were older (71.2 ± 11.7 vs. 63.1 ± 13.6 years, P < 0.001), more often Caucasian (76.8% vs. 61.8%, P < 0.001), and had more medical comorbidities (chronic obstructive pulmonary disease, cardiac history, diabetes, peripheral vascular disease, transient ischemic attack [TIA], P < 0.001). In contrast, dissection patients had higher American Society of Anesthesiology (ASA) classification score (58.5% had >3 ASA vs. 45.5%, P < 0.001), longer hospitalizations (10.2 ± 9.3 vs. 8.5 ± 10.4 days, P < 0.001), were more likely to have been transferred from another hospital or emergency room (58.4% vs. 48.3%, P < 0.001), and were more often emergent (32.4% vs. 15.4%, P < 0.001). In dissection patients, ASA classification score (OR, 1.49; 95% CI, 1.1-2.1) and dialysis (OR, 1.98; 95% CI, 1.0-3.9) were independent predictors for prolonged LOS. In aneurysm patients, dependent functional status (OR, 2.03; 95% CI, 1.4-2.8), diabetes (OR, 1.75; 95% CI, 1.1-2.8), cardiac history (OR, 1.37; 95% CI, 1.0-1.9), emergency status (OR, 1.98; 95% CI, 1.4-2.8), and dialysis (OR, 2.08; 95% CI, 1.2-3.7) predicted prolonged LOS. Postoperative complications including stroke/TIA; failure to wean from ventilator, sepsis, and pneumonia; and need for reoperation similarly increased LOS in both dissection and aneurysm patients. CONCLUSIONS: Dissection and aneurysm patients undergoing TEVAR are comprised of different patient populations, with dissection patients more often enduring prolonged hospitalizations. In contrast, TEVAR performed for nonemergent aneurysm repair had the shortest LOS. These data support the development of separate pathways defined by indication and acuity for patients undergoing TEVAR.

Characterization and outcomes of reinterventions in Food and Drug Administration-approved versus trial endovascular aneurysm repair devices.

OBJECTIVE: Published rates of reintervention after endovascular aneurysm repair (EVAR) range from 10% to 30%. We evaluated a single university center's experience with reinterventions in the context of Food and Drug Administration (FDA)-approved and trial devices. METHODS: Retrospective data collection was performed for patients who underwent infrarenal EVAR and required reintervention from 2000 to 2016. Trial devices included those used in FDA feasibility and pivotal trials. Time-to-event analysis was performed using Cox regression. Predictors of mortality and explantation were evaluated using logistic regression; survival analysis was performed using Kaplan-Meier methods. RESULTS: From 2000 to 2016, there were 1835 EVARs performed, and 137 patients (116 men; mean age, 72.2 ± 10.0 years) underwent reintervention with a mean aneurysm size of 5.9 ± 1.2 cm. The median follow-up was 5 years with an overall survival of 70.1%. The overall reintervention rate was 7.5%. FDA-approved devices had a reintervention rate of 6.4%, whereas trial devices had a rate of 14.4% (P < .001). For all devices, the most common cause of reintervention was type II endoleak (52.5%), followed by type I endoleak (18.2%), type III endoleak (9.5%), limb kink (7.3%), iliac occlusive disease (5.8%), endotension (1.5%), and other. The overall mean time to first reintervention was 2.3 ± 2.5 years, and univariate Cox regression identified male gender (hazard ratio, 1.91; 95% confidence interval [CI], 1.17-3.10; P = .010) and age at the time of EVAR (hazard ratio, 1.03; 95% CI, 1.01-1.05; P = .006) as risk factors for time to first reintervention. Among patients requiring reintervention, the mean number of reinterventions for trial devices was significantly greater than that for FDA-approved devices (2.18 vs 1.65; P = .01). Trial devices requiring reintervention had a nearly threefold higher odds for the need for more than two reinterventions (odds ratio, 2.88; 95% CI, 1.12-7.37; P = .034). Trial device, cause of reintervention, and type of reintervention were not predictive of the need for explantation or mortality, but the number of reinterventions was significantly associated with the need for explantation (odds ratio, 1.86; 95% CI, 1.17-2.96; P = .012). EVAR device and the need for explantation did not have an impact on mortality. CONCLUSIONS: Despite the rigorous nature of patient enrollment in clinical trials and the development of newer iterations of investigational devices, patients undergoing EVAR with trial devices are more likely to undergo a greater number of reinterventions than with FDA-approved devices. Although mortality and the need for explantation were not significantly associated with trial devices, the finding of a greater number of reinterventions highlights the need to properly inform patients willing to partake in investigational device trials.

Treating Peripheral Artery Disease in the Wake of Rising Costs and Protracted Length of Stay.

BACKGROUND: There has been growing scrutiny in the treatment of patients with peripheral artery disease due to the utilization of resources to manage this complex patient population. The purpose of this study was to determine the factors associated with prolonged length of stay (LOS > 7 days) following lower extremity bypass using data from the Vascular Quality Initiative as well as to define the additional costs incurred due to prolonged LOS in our health system. METHODS: Summary statistics were performed of patients undergoing lower extremity bypass from 2010 to 2015. Student's t-tests and χ2 tests were performed to compare those with and without prolonged LOS. Multivariable logistic regression was then performed to determine the independent predictors for increased LOS. We then compared our institutional LOS with that of representative institutions from the University Health System Consortium and evaluated the impact of prolonged LOS on limb salvage and survival. RESULTS: This study included 334 patients with a mean age of 66.4 ± 12.4 years, 64.7% males, 58.5% of white race, 11.1% on dialysis, 80.5% smokers, and 53.6% with diabetes. The mean LOS was 15.7 ± 12.2 days. Prolonged LOS was associated with transfer (15.4% vs. 2.3%, P = 0.001), diabetes (58.3% vs. 40.2%, P = 0.004), critical limb ischemia (71.3% vs. 49.4%, P < 0.001), preoperative need for ambulatory assistance (44.5% vs. 16.1%, P < 0.001), prior ipsilateral bypass (6.9% vs. 1.1%, P = 0.042), urgent surgery (39.7% vs. 9.8%, P < 0.001), tibial or distal target vessel (52.7% vs. 28.0%, P < 0.001), use of vein (65.4% vs. 46.3%, P = 0.002), return to operating room (42.6% vs. 1.2%, P < 0.001), ambulatory assistance (65.0% vs. 34.1%, P < 0.001) as well as discharge anticoagulant (22.8% vs. 9.8%, P = 0.010). Multivariable logistic regression identified urgency (odds ratio [OR] = 5.09, 95% confidence interval [CI] 2.16-12.02, P < 0.001), critical limb ischemia (OR = 3.12, 95% CI 1.65-5.90, P < 0.001), return to OR (OR = 40.30, 95% CI 5.36-303.20, P < 0.001), use of vein (OR = 2.19, 95% CI 1.18-4.07, P = 0.013), and the need for anticoagulation at discharge (OR = 2.56, 95% CI 1.03-6.33, P = 0.043) as independent predictors of LOS > 7 days. Prolonged hospital stays accounted for an additional $40,561.64 in total cost and $26,028 in direct costs incurred. Despite these increased costs, limb salvage and overall survival were not adversely impacted in the prolonged LOS group in follow-up. CONCLUSIONS: Lower extremity bypass is associated with a longer than expected LOS in our health system, much of which can be attributed to return to the OR for minor amputations and wound issues. This led to added total and direct costs, where the majority of this increase was attributable to prolonged LOS. Limb salvage and overall survival were preserved, however, in this subset of patients in follow-up. These findings suggest that lower extremity bypass patients are a resource-intensive population of patients, but that these costs are worthwhile in the setting of preserved limb salvage and overall survival.

Balloon-assisted deployment prevents endograft misalignment during hybrid aortic arch repair.

Misaligned deployment refers to eccentric flaring of the bare stent portion of the endograft that causes proximal device retroflexion resulting in suboptimal graft placement. A 71-year-old woman with 6.8-cm distal aortic arch aneurysm underwent hybrid repair with combination of open aortic arch debranching and subsequent thoracic endovascular aortic repair. During endograft deployment, misaligned opening occurred; this was corrected by using a balloon-assisted graft deployment. Follow up imaging continues to demonstrate complete aneurysm exclusion. Misaligned deployment is a clinical challenge; we hereby present a previously undescribed technique to accommodate this limitation of the current endograft technology.

Lower limb revascularization for PAD using a heparin-coated PTFE conduit.

OBJECTIVE: To assess the patency of the PROPATEN Graft in lower extremity bypasses. METHODS: We retrospectively reviewed all lower extremity bypasses with the PROPATEN Graft from 2007-2009 at a single institution. There were 68 implants--56% male; mean age 69. Comorbidities included hypertension (HTN; 81%), hyperlipidemia (72%), coronary artery disease (CAD; 74%), and smoking (59%). Most patients were Rutherford category 4 or higher. A total of 34% of patients had only 1 runoff vessel; 10% of patients required a complex concomitant procedure with sequential extremity revascularization. Statistics were via Kaplan Meier. RESULTS: Mean follow-up was 10.4 ± 8.0 months (0-30). Patency was excellent in all positions. Primary patency for all patients was 94.0% and 86.0% at 30 days and 18 months, respectively. Limb salvage at 30 days was 95%, and at 18 months was 90%. No patients developed HIT. Ten patients lost graft patency. These patients had severe peripheral vascular disease (PVD), with rest pain or tissue loss, poor runoff (no runoff or single vessel runoff), compromised inflow, and restored competitive flow. Fifty percent of the failed grafts were in the infrapopliteal position. Endovascular intervention and graft thrombectomy to restore patency was attempted in 2 patients and was unsuccessful. CONCLUSION: The GORE PROPATEN Vascular Graft demonstrates excellent patency in all arterial positions and may be the conduit of choice for all prosthetic bypasses.

Barriers to endovascular aortic aneurysm repair: past experience and implications for future device development.

Despite improvements in endovascular aortic aneurysm repair (EVAR) devices and techniques, significant anatomic constraints still preclude successful EVAR in a large number of patients. The authors sought to identify the current barriers to EVAR and examine their evolution over time. Patients were evaluated for potential endovascular repair by computed tomography angiography (CTA) with or without supplemental conventional arteriograms. The patient population was separated into 2 groups (A and B) based on early and late time periods in the experience with EVAR, corresponding to the availability of various devices. Group A (early) consisted of the Guidant Ancure, Medtronic Talent, and AneuRx devices and comprised patients presenting between April 1997 through June 2000. Group B (late) consisted of the Medtronic AneuRx, Cook Zenith, Edwards Lifepath, Gore Excluder, and Endologix PowerLink devices and comprised patients presenting between July 2000 and December 2003. Patient demographics and anatomic reasons for rejection were recorded in a database for statistical analysis. In total, 547 patients were evaluated (463 men, 84 women). Of these, 346 patients (63%; 312 men, 34 women) were deemed suitable candidates for EVAR and 201 (37%; 151 men, 50 women) were rejected. There was no significant difference in the overall rate of rejection in the early vs the late time period (34% A, 41% B, p = 0.08), but the number of exclusion criteria per patient decreased over time; patients rejected for EVAR had an overall average of 1.6 exclusion criteria (Group A, 1.9; Group B, 1.2). The reasons for rejection did significantly change over time. Specifically, rejection on the basis of inadequate arterial access, presence of extensive iliac artery aneurysms, or an inadequate proximal neck decreased. A disproportionate number of women were excluded throughout the study: Group A, 56% of women compared to 30% of men (p = 0.0003); Group B, 63% of women compared to 36% of men (p = 0.0022). Women were more likely than men to have inadequate arterial access routes. In addition, patients with high operative risk were also more likely to be excluded from EVAR, a finding that persisted over time. Anatomic constraints continue to pose significant challenges to aortic endografting. Progress has been made in that technological advances have conquered some of the previous anatomic challenges, chiefly those of arterial access and treatment of concomitant iliac aneurysm disease. However, the overall rate of rejection for EVAR remains the same. The chief anatomic barriers continue to be the difficult aortic neck and management of branched vascular segments.

Endovascular therapy of symptomatic innominate-subclavian arterial occlusive lesions.

The purpose of this study was to determine the safety and efficacy of angioplasty and stenting for symptomatic innominate-subclavian lesions by review of records of symptomatic patients undergoing angioplasty and stenting of high-grade lesions (>80%) of the innominate and subclavian arteries. Follow-up consisted of history (symptoms) and physical examination (pulses and blood pressures) at 1, 3, 6, and then every 12 months plus an annual duplex ultrasound examination. Between 1998 to 2003, 25 patients (27 lesions) were treated. Ages ranged from 48 to 89 years. Symptoms included vertebrobasilar/steal (15), claudication (6), ischemia (4), and coronary artery bypass grafting/left internal mammary artery (2). There were 7 occlusions and 20 high-grade stenoses. Access was attempted via brachial cutdown (19) or percutaneous puncture of the brachial (2) or femoral arteries (10). Twenty-two lesions were stented with either self-expanding (13) or balloon-expandable (9) stents. Technical success was 89%; 3 occluded lesions could not be crossed owing to complete occlusion. The remaining 4 occlusions were all crossed via a retrograde approach. The mean difference in systolic blood pressure between upper limbs decreased from 36 mm Hg (preprocedure) to 10 mm Hg (postprocedure). There were no procedure-related complications. Mean follow-up was 18 months (range 1-62 months). One patient died 4 months after the procedure secondary to complications from pulmonary surgery unrelated to the percutaneous transluminal angioplasty/stent. Of the 4 successfully treated occlusions, 2 were followed up to 3 years with continued patency. Three patients developed recurrent stenoses documented by duplex examination. However, these patients remained asymptomatic and were not treated. Endovascular management of high-grade lesions of the subclavian or innominate arteries is safe and efficacious and may be considered as a first line of therapy. Continued follow-up is needed to assess long-term patency.

Outcomes of accessory renal artery occlusion during endovascular aneurysm repair.

OBJECTIVE: Accessory renal arteries are frequently encountered when patients are evaluated for endovascular abdominal aortic aneurysm repair (EVAR). Some have considered their presence a contraindication to EVAR in fear of endoleak and the end result of renal function. We sought to determine whether the coverage of accessory renal arteries during EVAR was associated with any adverse sequelae. METHODS: Retrospective review of the medical records and computed tomographic scans of all patients undergoing EVAR (1998 to 2003) was performed. Note was made of the presence or absence of accessory renal arteries, hypertension, and renal function. Preoperative computed tomographic images were compared with postoperative images to determine the presence of renal infarction. A control group of 26 consecutive patients without accessory renal arteries was used for comparison of the results of EVAR. RESULTS: EVAR was performed in 550 patients over the study interval. The mean follow-up was 16 months (range, 1-48 months). The average age was 74 years (range, 57-90 years). Thirty-five patients (6.6%; 32 male and 3 female) were documented to have accessory renal arteries; the average number of accessory arteries was 2 (range, 1-4). Bilateral accessory arteries were present in 13 patients: all but 1 patient (n = 34) had a left-sided accessory renal artery, and 23 had a right-sided accessory renal artery. EVAR was performed with a variety of endografts: AneuRx (n = 10), Talent (n = 7), PowerLink (n = 7), Zenith (n = 5), LifePath (n = 4), and Ancure (n = 2). There were no mortalities. Twelve endoleaks were documented: three type I, eight type II, and one type III. The accessory renal arteries were not implicated in any of the endoleaks, and none of these accessory vessels was embolized before or after EVAR. Seven patients (20%) had renal infarcts associated with EVAR that were noted on follow-up computed tomographic scans. The mean follow-up for patients with segmental infarction was 23 months (range, 8-48 months). Hypertensive status did not change in any patient in whom an accessory renal artery had been covered. The average serum creatinine was 1.08 mg/dL (range, 0.6-1.8 mg/dL) before EVAR in patients with accessory renal arteries covered by an endovascular graft and did not change significantly in response to EVAR. Serum creatinine increased almost twofold in two patients but spontaneously resolved in follow-up. The average preoperative creatinine clearance was 79 mL/min (range, 35-166 mL/min) in patients without an accessory renal artery and was 80 mL/min (range, 35-167 mL/min) after EVAR. The average preoperative creatinine clearance was 67 mL/min (range, 31-137 mL/min) in patients with an accessory renal artery and 68 mL/min (range, 45-83 mL/min) in patients with renal infarcts. None of the patients required temporary or permanent dialysis. There was no difference between control patients and patients with covered accessory renal arteries with respect to hypertensive status, presence of renal infarcts, serum creatinine, or creatinine clearance after EVAR. CONCLUSIONS: Occlusion of accessory renal arteries is not associated with clinically significant signs or symptoms, even in patients with mild or moderate renal insufficiency. Sacrifice of accessory renal arteries most commonly does not lead to detectable renal infarction, either clinically or radiographically. When segmental infarction of the kidney does result, it seems to be well tolerated in this group of patients. Accessory renal arteries were not found to contribute to endoleaks and should not be prophylactically embolized.

Mineral volume and morphology in carotid plaque specimens using high-resolution MRI and CT.

OBJECTIVE: High-resolution MRI methods have been used to evaluate carotid artery atherosclerotic plaque content. The purpose of this study was to assess the performance of high-resolution MRI in evaluation of the quantity and pattern of mineral deposition in carotid endarterectomy (CEA) specimens, with quantitative micro-CT as the gold standard. METHODS AND RESULTS: High-resolution MRI and CT were compared in 20 CEA specimens. Linear regression comparing mineral volumes generated from CT (VCT) and MRI (VMRI) data demonstrated good correlation using simple thresholding (VMRI=-0.01+0.98VCT; R2=0.90; threshold=4xnoise) and k-means clustering methods (VMRI=-0.005+1.38VCT; R2=0.93). Bone mineral density (BMD) and bone mineral content (BMC [mineral mass]) were calculated for CT data and BMC verified with ash weight. Patterns of mineralization like particles, granules, and sheets were more clearly depicted on CT. CONCLUSIONS: Mineral volumes generated from MRI or CT data were highly correlated. CT provided a more detailed depiction of mineralization patterns and provided BMD and BMC in addition to mineral volume. The extent of mineralization as well as the morphology may ultimately be useful in assessing plaque stability.

Midterm pivotal trial results of the Talent Low Profile System for repair of abdominal aortic aneurysm: analysis of complicated versus uncomplicated aortic necks.

OBJECTIVE: This study was undertaken to determine whether a complicated aortic neck is associated with unfavorable outcome after abdominal aortic aneurysm (AAA) endografting. METHODS: In a prospective pivotal clinical trial, 237 consecutive patients underwent implantation of the bifurcated Talent Low Profile System. Patients were divided into 2 groups, those with complicated aortic necks (short, <15 mm; very short, < or =10 mm; dilated, >28 mm; angulated, >45 degrees; calcified; and thrombus-lined) versus those with uncomplicated neck anatomy. Major outcome parameters included procedure time, operative blood loss, transfusion requirements, volume of contrast medium used during the implant procedure, endoleaks, migration, limb patency, AAA regression, conversion to open repair, morbidity, and mortality. Mean follow-up was 620.5 days. RESULTS: Overall, 32% of aortic necks were short, 19% were very short, 20% were dilated, 18% were calcified, 8.5% were thrombus-lined, and 19.9% were angulated. Thirty percent and 70% of patients, respectively, were stratified to the uncomplicated and complicated groups ( P < .01. Procedure time, operative blood loss, transfusions, volume of contrast medium used in the implant procedure, migration, endograft patency, AAA sac regression, conversion to open repair, and mortality were not significantly different in necks with complicated versus uncomplicated anatomy. At 21 months, sacs were regressing or stable in 98% (complicated) versus 96% (uncomplicated). Primary graft limb patency was 100% in both groups. The endoleak rate was 4.3% (complicated) versus 17% (uncomplicated) at 18 months, but this difference was not statistically significant. Adverse renal events, however, occurred in 27.5% (complicated) versus 13.6% (uncomplicated; P = .04). CONCLUSIONS: Complicated aortic neck is not associated with unfavorable outcome at midterm follow-up after AAA endografting. However, statistically more adverse renal events occur in patients with complicated neck anatomy.

Decreased use of iliac extensions and reduced graft junctions with software-assisted centerline measurements in selection of endograft components for endovascular aneurysm repair.

OBJECTIVE: The purpose of this study was to determine the impact of using computerized software-assisted centerline measurements for extensions and graft junctions during the selection of endograft components for modular aortic endografts in endovascular repair of abdominal aortic aneurysms. METHODS: From April 1998 to December 2002, 289 modular aortic endografts were implanted at our institution. These included 248 grafts (prior to 2002, group 1) with components selected on the basis of manual caliper measurements from combined contrast computed tomography (CT) and marker-catheter arteriography data, and 41 grafts (2002, group 2) with components selected with the use of computerized software that allowed for centerline measurements on 3-dimensional reconstructions based on CT data. These 2 groups were compared for the number and type of extensions required per case. Seventeen other relevant variables were analyzed for their potential influence on selection of endograft components. These variables included age, gender, maximum aneurysm size, level of distal fixation, length and diameter at the fixation points, endograft manufacturer (make), and configuration. The significance of the observed differences was analyzed with a multivariate regression model, adjusting for potentially confounding preoperative measures. RESULTS: Multivariate analysis demonstrated that the number of right iliac extensions, left iliac extensions, total extensions, and total graft junctions was significantly reduced by the use of computerized software-assisted centerline measurements (group 2) compared with caliper measurements (group 1), independent of all other 17 preoperative variables. Notably, the mean number of required right iliac extensions was double in group 1 versus group 2. CONCLUSIONS: Centerline software-assisted measurements can significantly reduce the need for iliac extensions and, concomitantly, the number of required endograft junctions. On average, twice as many extensions were required for right iliac fixation when the manual caliper measurements were used compared with software-assisted measurements. These findings are highly relevant to issues of total endograft cost and long-term endograft integrity and focus attention on the tools that may need to be considered standards of care rather than optional for selection of endograft components.

The utility of commercially available endografts in the treatment of contained ruptured abdominal aortic aneurysm with hemodynamic stability.

PURPOSE: Food and Drug Administration-approved endografts are suitable for the elective repair of abdominal aortic aneurysms (AAAs) with favorable aneurysm anatomy. Our aim is to illustrate the feasibility and versatility of commercially available endografts for emergency AAA repair in hemodynamically stable AAA rupture. METHODS: From June 2001 to July 2002, five patients presented with severe abdominal pain and were diagnosed with contained rupture of an infrarenal AAA. In all cases, patients were deemed unfit to withstand conventional open repair by both the referring outside medical center as well as our center's team. All patients were hemodynamically stable on arrival at our medical center. Measurement and selection of endovascular devices were based on computed tomography (CT) scans performed emergently at the outside referring center. The required emergently procured endografts were obtained within 2 to 4.5 hours (mean, 3.1 hours) of presentation. Complex anatomy at the proximal and distal fixation zones or difficult access was present in every case. RESULTS: All patients survived endograft repair and had successful exclusion of their aneurysm sac on the basis of intraoperative arteriography and postoperative CT surveillance. All were discharged to home at baseline function within a mean of 6.8 days (range, 2-13 days). There were no deaths. There was one postoperative pulmonary embolism, one myocardial infarct, and one type 2 endoleak. Mean operative time and blood loss were 4.67 hours and 217 mL, respectively. At a mean follow-up of 18 months, CT scans showed stable or shrinking aneurysm sacs. CONCLUSIONS: In patients with contained ruptured AAAs who present with hemodynamic stability and comorbidities that preclude open surgery, commercially available endografts are a versatile treatment option even in the face of complicated aneurysm anatomy.