Faculty Bibliography

INTRODUCTION/BACKGROUND:Aortic graft infection remains a considerable clinical challenge, and it is unclear which variables are associated with adverse outcomes among patients undergoing partial resection. METHODS:A retrospective, multi-institutional study of patients who underwent partial resection of infected aortic grafts from 2002 to 2014 was performed using a standard database. Baseline demographics, comorbidities, operative, and postoperative variables were recorded. The primary outcome was mortality. Descriptive statistics, Kaplan-Meier (KM) survival analysis, and Cox regression analysis were performed. RESULTS:One hundred fourteen patients at 22 medical centers in 6 countries underwent partial resection of an infected aortic graft. Seventy percent were men with median age 70 years. Ninety-seven percent had a history of open aortic bypass graft: 88 (77%) patients had infected aortobifemoral bypass, 18 (16%) had infected aortobiiliac bypass, and 1 (0.8%) had an infected thoracic graft. Infection was diagnosed at a median 4.3 years post-implant. All patients underwent partial resection followed by either extra-anatomic (47%) or in situ (53%) vascular reconstruction. Median follow-up period was 17 months (IQR 1, 50 months). Thirty-day mortality was 17.5%. The KM-estimated median survival from time of partial resection was 3.6 years. There was no significant survival difference between those undergoing in situ reconstruction or extra-anatomic bypass (P = 0.6). During follow up, 72% of repairs remained patent and 11% of patients underwent major amputation. On univariate Cox regression analysis, Candida infection was associated with increased risk of mortality (HR 2.4; P = 0.01) as well as aortoenteric fistula (HR 1.9, P = 0.03). Resection of a single graft limb only to resection of abdominal (graft main body) infection was associated with decreased risk of mortality (HR 0.57, P = 0.04), as well as those with American Society of Anesthesiologists classification less than 3 (HR 0.35, P = 0.04). Multivariate analysis did not reveal any factors significantly associated with mortality. Persistent early infection was noted in 26% of patients within 30 days postoperatively, and 39% of patients were found to have any post-repair infection during the follow-up period. Two patients (1.8%) were found to have a late reinfection without early persistent postoperative infection. Patients with any post-repair infection were older (67 vs. 60 years, P = 0.01) and less likely to have patent repairs during follow up (59% vs. 32%, P = 0.01). Patients with aortoenteric fistula had a higher rate of any post-repair infection (63% vs. 29%, P < 0.01) CONCLUSION: This large multi-center study suggests that patients who have undergone partial resection of infected aortic grafts may be at high risk of death or post-repair infection, especially older patients with abdominal infection not isolated to a single graft limb, or with Candida infection or aortoenteric fistula. Late reinfection correlated strongly with early persistent postoperative infection, raising concern for occult retained infected graft material.

IMPORTANCE:The use of statins in patients with symptomatic peripheral artery disease remains suboptimal despite strong clinical practice guideline recommendations; however, it is unknown whether rates are associated with substantial improvements after lower extremity revascularization. OBJECTIVE:To report longitudinal trends of statin use in patients with peripheral artery disease undergoing lower extremity revascularization and to identify the clinical and procedural characteristics associated with prescriptions for new statin therapy at discharge. DESIGN, SETTING, AND PARTICIPANTS:This was a retrospective cross-sectional study using data from the Vascular Quality Initiative registry of patients who underwent lower extremity peripheral artery disease revascularization from January 1, 2014, through December 31, 2019. The Vascular Quality Initiative is a multicenter registry database including academic and community-based hospitals throughout the US. Patients aged 18 years or older undergoing lower extremity revascularization with available statin data (preprocedure and postprocedure) were included. Those not receiving statin therapy for medical reasons were excluded from final analyses. EXPOSURES:Patients undergoing lower extremity revascularization for whom statin therapy is indicated. MAIN OUTCOMES AND MEASURES:Multivariate logistic regression was used to determine the clinical and procedural characteristics associated with new statin prescription for patients not already taking a statin preprocedure. The overall rates of statin prescription as well as rates of new statin prescription at discharge were determined. In addition, the clinical, demographic, and procedural characteristics associated with new statin prescription were analyzed. RESULTS:There were 172 025 procedures corresponding to 125 791 patients (mean [SD] age, 67.7 [11.0] years; 107 800 men [62.7%]; and 135 405 White [78.7%]) included in the analysis. Overall rates of statin prescription at discharge improved from 17 299 of 23 093 (75%) in 2014 to 29 804 of 34 231 (87%) in 2019. However, only 12 790 of 42 020 patients (30%) not already taking a statin at the time of revascularization during the study period were newly discharged with a statin medication. New statin prescription rates were substantially lower after endovascular intervention (7745 of 29 581 [26%]) than after lower extremity bypass (5045 of 12 439 [41%]). Body mass index of 30 or greater (odds ratio [OR], 1.13; 95% CI, 1.04-1.24; P < .001), diabetes (diet-controlled vs no diabetes, OR, 1.22; 95% CI, 1.05-1.41; P = .01), smoking (current vs never, OR, 1.32; 95% CI, 1.21-1.45; P < .001), hypertension (OR, 1.19; 95% CI, 1.09-1.29; P < .001), and coronary heart disease (OR, 1.26; 95% CI, 1.17-1.35; P < .001) were associated with an increased likelihood of new statin prescription after endovascular intervention, whereas female sex, older age, antiplatelet use, and prior peripheral revascularization were associated with a decreased likelihood. CONCLUSIONS AND RELEVANCE:In this cross-sectional study, although statin use was associated with a substantial improvement after lower extremity revascularization, more than two-thirds of patients not already taking a statin preprocedure remained not taking a statin at discharge. Further investigations to understand the clinical implications of these findings and develop clinician- and system-based interventions are needed.

BACKGROUND:Thoracic endovascular aortic repair (TEVAR) for type B aortic dissections is used to promote false lumen (FL) thrombosis and favorable aortic remodeling, but its impact on occlusion of FL origin branch vessels has not been widely described. We compare FL versus true lumen (TL) branch vessel patency after TEVAR. METHODS:Patients treated by TEVAR for type B aortic dissection in zones 2-5 in the Vascular Quality Initiative from 2009 to 2018 were evaluated. The primary outcome was postoperative branch patency. Secondary outcomes were need for branch vessel intervention, preoperative origin, and postoperative patency of individual branch vessels (celiac, superior mesenteric artery, renal arteries, and iliac arteries). A subset analysis was performed comparing acute and chronic dissections. RESULTS:Of 11,774 patients, 1,484 met criteria for analysis. The left renal was the most common to have FL origin (21.6%), whereas right and left common iliac arteries were the most likely to originate off both lumens (BLs; 22% and 24%). Branch vessels that originated from the TL, FL, BLs, or were obstructed had postoperative patency rates of 99%, 99%, 99%, and 87% (P < 0.0001). Branch vessel treatment was performed in 5% of patients. The right (2.5%) and left (2.8%) renal arteries were the most frequently obstructed branches postoperatively. On multivariate analysis, preoperatively obstructed branches (odds ratio 0.03, P < 0.0001) were negatively associated with postoperative branch patency and branch vessel treatment (odds ratio 3.8, P = 0.004) was positively associated with postoperative patency. FL or BL origin, number of zones covered by TEVAR, urgency, dissection chronicity (acute versus chronic), and demographics were not independently associated with patency. These findings remained unchanged in the subset analysis of only acute dissections. CONCLUSIONS:Branch vessel patency rates after TEVAR for a type B aortic dissection are high and are not significantly different for FL or BL origin vessels compared with TL vessels. Branches that are patent before TEVAR almost always remain patent after TEVAR, but branch vessel stenting may be required in less than 5%.

OBJECTIVE:We reviewed the complications associated with perioperative lumbar drain (LD) placement for endovascular aortic repair. METHODS:Patients who had undergone perioperative LD placement for endovascular repair of thoracic and thoracoabdominal aortic pathologies from 2010 to 2019 were reviewed. The primary endpoints were major and minor LD-associated complications. Complications that had resulted in neurological sequelae or had required an intervention or a delay in operation were defined as major. These included intracranial hemorrhage, symptomatic spinal hematoma, cerebrospinal fluid (CSF) leak requiring intervention, meningitis, retained catheter tip, arachnoiditis, and traumatic (or bloody) tap resulting in delayed operation. Minor complications were defined as a bloody tap without a delay in surgery, asymptomatic epidural hematoma, and CSF leak with no intervention required. Isolated headaches were recorded separately owing to the minimal clinical impact. RESULTS:A total of 309 LDs had been placed in 268 consecutive patients for 222 thoracic endovascular aortic repairs, 85 complex endovascular aortic repairs (EVARs; fenestrated branched EVAR/parallel grafting), and 2 EVARs (age, 65 ± 13 years; 71% male) for aortic pathology, including aneurysm (47%), dissection (49%), penetrating aortic ulcer (3%), and traumatic injury (0.6%). A dedicated neurosurgical team performed all LD procedures; most were performed by the same individual, with a technical success rate of 98%. Radiologic guidance was required in 3%. The reasons for unsuccessful placement were body habitus (n = 2) and severe spinal disease (n = 3). Most were placed prophylactically (96%). The overall complication rate was 8.1% (4.2% major and 3.9% minor). Major complications included spinal hematoma with paraplegia in 1 patient, intracranial hemorrhage in 2, meningitis in 2, arachnoiditis in 3, CSF leak requiring a blood patch in 3, bloody tap delaying the operation in 1, and a retained catheter tip in 1 patient. Patients who had undergone previous LD placement had experienced significantly more major LD-related complications (12.2% vs 3%; P = .019). The rate of total LD-associated complications did not differ between prophylactic and emergent therapeutic placements (8.1% vs 7.7%; P = 1.00) nor between major or minor complications. On multivariate analysis, previous LD placement and an overweight body mass index were the only independent predictors of major LD-related complications. CONCLUSIONS:The complications associated with LD placement can be severe even when performed by a dedicated team. Previous LD placement and overweight body mass index were associated with a significantly greater risk of complications; however, emergent therapeutic placement was not. Although these risks are justified for therapeutic LD placement, the benefit of prophylactic LD placement to prevent paraplegia should be weighed against these serious complications.

OBJECTIVE:Endovascular abdominal aortic repair can involve the incorporation of renal arteries. Revascularization after intentional or unintentional renal artery (RA) coverage is not always technically successful, and the loss of a single RA may result in the need for postoperative dialysis. Thus, we compared the outcomes after endovascular aneurysm repair (EVAR) stratified by RA involvement (RAI). METHODS:Patient data from the Vascular Quality Initiative from 2009 to 2018 registry were analyzed. The exclusion criteria were preoperative dialysis, missing RAI data, and repair above the superior mesenteric artery. The repair type cohorts were defined as (1) no RAI (NRAI), (2) RAI with revascularization (RAI-R), and (3) RAI with no revascularization (RAI-NR). A sensitivity analysis was performed by excluding ruptured presentations. The primary outcome was the need for postoperative dialysis. The secondary outcomes were 30-day mortality, dialysis at follow-up, postoperative renal function, and 2-year survival. Multivariate analysis was used to determine the independent predictors for postoperative dialysis. The 2-year survival analysis was performed using Kaplan-Meier log-rank test. RESULTS:Of 54,020 patients in the EVAR and TEVAR (thoracic EVAR)/complex EVAR modules in the Vascular Quality Initiative, 25,724 met the criteria for inclusion (NRAI, n = 24,879; RAI-R, n = 733; RAI-NR, n = 112). The demographics and comorbidities were similar among the three groups. The RAI-NR group had more frequently had ruptured or symptomatic aneurysms. The postoperative dialysis requirement was higher in the RAI-NR group (NRAI, 0.7%; RAI-R, 2.2%; RAI-NR, 17%; P < .0001), as were the 30-day mortality and dialysis requirement at follow-up. On multivariate analysis, RAI-R (odds ratio [OR], 2.2; P = .03) and RAI-NR (OR, 5.9; P < .0001) were independent predictors of postoperative dialysis and remained so after excluding ruptured presentations (RAI-R: OR, 3; P = .003; RAI-NR: OR, 22.3; P < .0001). Other independent predictors of the need for postoperative dialysis were worse preoperative renal function, a symptomatic presentation, any preoperative or intraoperative blood transfusion, and larger blood loss (≥200 mL). Excluding those with rupture, the overall survival at 2 years on Kaplan-Meier analysis was lower for the RAI-NR group (NRAI, 92%; RAI-R, 89%; RAI-NR, 80%; P = .004). CONCLUSIONS:RAI is highly predictive of the need for postoperative and permanent dialysis after EVAR. RAI-NR was associated with lower overall survival. These risks should be considered when planning and performing EVAR and should be weighed against the risks of open repair when considering the treatment options.

In atherosclerosis, resident vascular smooth muscle cells (VSMCs) in the blood vessels become highly plastic and undergo phenotypic switching from the quiescent, contractile phenotype to the migratory and proliferative, synthetic phenotype. Additionally, recent VSMC lineage-tracing mouse models of atherosclerosis have found that VSMCs transdifferentiate into macrophage-like and osteochondrogenic cells and make up to 70% of cells found in atherosclerotic plaques. Given VSMC phenotypic switching is regulated by microRNA-145 (miR-145), we hypothesized that nanoparticle-mediated delivery of miR-145 to VSMCs has the potential to mitigate atherosclerosis development by inhibiting plaque-propagating cell types derived from VSMCs. To test our hypothesis, we synthesized miR-145 micelles targeting the C-C chemokine receptor-2 (CCR2), which is highly expressed on synthetic VSMCs. When miR-145 micelles were incubated with human aortic VSMCs in vitro, >90% miR-145 micelles escaped the lysosomal pathway in 4 hours and released the miR cargo under cytosolic levels of glutathione, an endogenous reducing agent. As such, miR-145 micelles rescued atheroprotective contractile markers, myocardin, α-SMA, and calponin, in synthetic VSMCs in vitro. In early-stage atherosclerotic ApoE^-/- mice, one dose of miR-145 micelles prevented lesion growth by 49% and sustained an increased level of miR-145 expression after 2 weeks post-treatment. Additionally, miR-145 micelles inhibited 35% and 43% plaque growth compared to free miR-145 and PBS, respectively, in mid-stage atherosclerotic ApoE^-/- mice. Collectively, we present a novel therapeutic strategy and cell target for atherosclerosis, and present miR-145 micelles as a viable nanotherapeutic that can intervene atherosclerosis progression at both early and later stages of disease.

OBJECTIVE:Aortic dissection can result in devastating cerebral, visceral, renal, spinal, and extremity ischemia. We describe the management and outcomes of patients presenting with aortic dissection and lower extremity malperfusion (LEM). METHODS:A single-center institutional aortic database was queried for patients with aortic dissection and LEM from 2011 to 2019. The primary end point was resolution of LEM after aortic repair. Secondary end points were amputation, in-hospital mortality, time to intervention, and postoperative complications. RESULTS:Of 769 patients with aortic dissection, 42 (5.5%) presented acutely with LEM: 16 with Stanford type A and 26 Stanford type B aortic dissection (age 55 ± 13 years; 90% men). Most presented as Rutherford IIB symptoms, but patients with type A had Rutherford III more often, compared with those with type B. Aortic repair was performed before limb interventions in 36 patients (86%; 19 TEVAR, 16 open arch and ascending repair, and 1 open descending aortic repair with fenestration). Seven (19%) had immediate failure with persistent malperfusion recognized in the operating room and underwent additional limb intervention, including extra-anatomic revascularization (n = 4), iliac stenting (n = 2), and femoral patch with septal fenestration or tacking (n = 2). Three patients (8%) had early delayed failure requiring extra-anatomic bypass in two and amputation in one. In contrast, six patients had limb-first intervention with extra-anatomic revascularization. None had immediate failure, but one-half had early delayed failure requiring proximal aortic intervention: two TEVAR and one open aortic fenestration. Limb-first patients were more likely to have early delayed failure compared with aortic dissection treated first patients (50% vs 8%; P = .029). The amputation rate was 2%, occurring in one type A patient. The overall in-hospital mortality was 7% (n = 3), with no difference between type A and type B aortic dissection. There was no difference in surgical site infection, postoperative dialysis need, stroke, and myocardial infarction. CONCLUSIONS:In patients presenting with acute aortic dissection with limb ischemia, resolution of the malperfusion occurs in the majority of cases after primary aortic dissection intervention, emphasizing the usefulness of urgent TEVAR for complicated type B and open repair of type A before lower extremity intervention. Limb-first interventions have a higher early delayed failure rate and thus require more frequent reoperation. However, the overall amputation rate in LEM owing to aortic dissection remains low.

OBJECTIVE:A hospital-wide quality improvement process through a care delivery redesign (CDR) was initiated to improve patient care efficiency, clinical documentation, and length of stay (LOS). The impact of CDR was assessed through LOS, unplanned readmission rates, and hospital financial metrics. METHODS:The CDR team consisted of the Chief of Vascular Surgery, inpatient nurse practitioner, dedicated case manager, clinical documentation improvement specialist, and vascular surgery residents and faculty. The nurse practitioner facilitated patient care coordination, resident system-based education, and multidisciplinary collaboration. Tools created to track performance and to ensure sustainability included daily discussions of patient care barriers and solutions; standardized order sets; a mobile app for residents containing resident service expectations, disease-specific resources, and vascular surgery journal links; and a weekly inpatient tracker showing real-time patient care data. Outcome measures included LOS, case mix index, contribution margin, and unplanned readmissions. Each outcome was determined for all inpatient admissions the year before and the 12 months after CDR was initiated. Outcomes were compared between the two groups. RESULTS:Implementation of CDR resulted in a 23% decrease in LOS (P = .003), reducing the gap to the Centers for Medicare and Medicaid Services geometric mean LOS from 2.1 days to 0.5 day (P < .001). Clinical documentation resulted in an increase in case mix index of 10% (P = .011). The 30-day unplanned readmission rates did not change in the 12 months after CDR was initiated compared with the year before (P = .92). Financial data demonstrated decreased variable cost and increased revenue resulting in a $1.89 million increase in contribution margin. CONCLUSIONS:A CDR predicated on a dedicated service line advanced practitioner, clinical documentation education, weekly service tracker review, and real-time management of system-related barriers to patient care is described. Implementation of the CDR reduced hospital LOS with no change in unplanned readmissions and provided significant financial benefit to the hospital by increasing revenue and decreasing variable cost.

Left subclavian artery revascularization during endovascular repair of aortic dissection is often accomplished by left carotid-subclavian artery bypass or transposition. In situ fenestration of thoracic stent grafts provides an alternative method of revascularization without manipulation of the left carotid artery. We describe a case whereby in situ laser fenestration, combined with catheter-directed thrombectomy, was utilized to revascularize a thrombosed left subclavian artery following a frozen elephant trunk repair of type A aortic dissection. A 75-year-old male presented with pericardial tamponade and aortic insufficiency, secondary to type A aortic dissection. Patient underwent an emergent replacement of the aortic root, valve, arch, and ascending aorta in the frozen elephant trunk configuration. The innominate and left carotid arteries were revascularized with a bifurcated bypass graft from the ascending aortic graft. The left subclavian artery (LSCA) was covered with an antegrade deployment of a cTAG stent graft. During the immediate postoperative period, the patient was found to have a dissection of the left common carotid artery (LCCA) and pseudoaneurysm of the bypass graft anastomosis. The left carotid artery was replaced up to the proximal internal carotid. During rehabilitation, the patient developed left subclavian steal syndrome, with a CT angiography demonstrating thrombosis of the subclavian origin, and duplex ultrasound showing a reversal of the left vertebral flow. In order to revascularize the left subclavian artery without using the left carotid as the inflow, the in situ laser fenestration technique was planned. The vertebral artery origin was protected with a neuroclip through a supraclavicular incision. Through a brachial artery cutdown, a 9Fr flex sheath was positioned at the origin of the subclavian artery. A suction thrombectomy catheter was used to create a central channel in the thrombus. A 0.035″ 3.2 mm over-the-wire laser atherectomy catheter was used to create a fenestration through the cTAG stent graft. The subclavian branch stent was stented with an iCast balloon-expandable covered stent, excluding the mural thrombus. The patient recovered well with resolution of symptoms and was discharged home. Postoperative CT scan showed patent left subclavian branch stent and no endoleak across the fenestration of the aortic stent graft. Delayed laser in situ fenestration of a PTFE stent graft can be performed safely. The vertebral artery protection and catheter-directed thrombectomy are important adjuncts to reduce the risk of posterior stroke.