Technique and Outcomes of Concomitant Aortic and Caval Resection and Reconstruction for Retroperitoneal Tumors.

BACKGROUND: Major vascular involvement is often considered a contraindication to resection of malignant tumors, but in highly selected patients, it can be performed safely, with results that are highly dependent upon the tumor biology. Resection of both the aorta and inferior vena cava (IVC) is a rare undertaking, requiring both favorable tumor biology and a patient fit for a substantial surgical insult; nevertheless, it provides the possibility of a cure. METHODS: Patients requiring resection and reconstruction of both the aorta and IVC from 2009 through 2019 at 2 university medical centers were included. Patient characteristics, operative technique, and outcomes were retrospectively collected. RESULTS: We identified 9 patients, all with infrarenal reconstruction or repair of the aorta and IVC. All cases were performed with systemic heparinization and required simultaneous aortic and caval cross-clamping for tumor resection. No temporary venous or arterial bypass was used. Since arterial reperfusion with the IVC clamped was poorly tolerated in 1 patient, venous reconstruction was typically completed first. Primary repair was performed in 1 patient, while 8 required replacements. In 2 patients, aortic homograft was used for replacement of both the aortoiliac and iliocaval segments in contaminated surgical fields. In the remaining 6, Dacron was used for arterial replacement; either Dacron (n = 2) or polytetrafluoroethylene (n = 4) were used for venous replacement. Patients were discharged after a median stay of 8 days (range: 5-16). At median follow-up of 17 months (range 3-79 months), 2 patients with paraganglioma and 1 patient with Leydig cell carcinoma had cancer recurrences. Venous reconstructions occluded in 3 patients (38%), although symptoms were minimal. One patient presented acutely with a thrombosed iliac artery limb and bilateral common iliac artery anastomotic stenoses, treated successfully with thrombolysis and stenting. CONCLUSIONS: Patients with tumor involving both the aorta and IVC can be successfully treated with resection and reconstruction. En bloc tumor resection, restoration of venous return before arterial reconstruction, and most importantly, careful patient selection, all contribute to positive outcomes in this otherwise incurable population.

A large series of true pancreaticoduodenal artery aneurysms.

INTRODUCTION: True pancreaticoduodenal artery aneurysms (PDAAs) are rare, and prior reports often fail to distinguish true aneurysms from pseudoaneuryms. We sought to characterize all patients who presented to our health system from 2004 to 2019 with true PDAAs, with a focus on risk factors, interventions, and patient outcomes. METHODS: Patients were identified by querying a single health system picture archiving and communication system database for radiographic reports noting a PDAA. A retrospective chart review was performed on all identified patients. Patients with pseudoaneurysm, identified as those with a history of pancreatitis, abdominal malignancy, hepatopancreaticobiliary surgery, or abdominal trauma, were excluded. Continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact tests. RESULTS: A total of 59 true PDAAs were identified. Forty aneurysms (68%) were intact (iPDAAs) and 19 (32%) were ruptured (rPDAAs) at presentation. The mean size of rPDAAs was 16.4 mm (median size, 14.0 mm; range, 10-42 mm), and the mean size of iPDAAs was 19.4 mm (median size, 17.5 mm; range, 8-88 mm); this difference was not statistically significant (P = .95). Significant celiac disease (occlusion or >70% stenosis) was noted in 39 aneurysms (66%). Those with rupture were less likely to have significant celiac disease (42% vs 78%; P = .017) and less likely to have aneurysmal wall calcifications (6% vs 53%; P = .002). Thirty-seven patients underwent intervention (63%), with eight (22%) undergoing concomitant hepatic revascularization (two stents and six bypasses) due to the presence of celiac disease. Eighteen patients with occluded celiac arteries underwent aneurysm intervention; of those, 11 were performed without hepatic revascularization (61.1%). Those with rPDAAs experienced an aneurysm-related mortality of 10.5%, whereas those with iPDAAs experienced a rate of 5.6%. One patient with celiac occlusion and PDA rupture who did not undergo hepatic artery bypass expired postoperatively from hepatic ischemia. rPDAAs showed a trend toward the increased need for aneurysm-related endovascular or open reintervention, but this was not statistically significant (47% vs 28%; P = .13). CONCLUSIONS: These findings support previous reports that the rupture risk of PDAAs is independent of size, their development is often associated with significant celiac stenosis or occlusion, and rupture risk appears decreased in patients with concomitant celiac disease or aneurysm wall calcifications. Endovascular intervention is the preferred initial treatment for both iPDAAs and rPDAAs, but reintervention rates are high in both groups. The role for hepatic revascularization remains uncertain, but it does not appear to be mandatory in all patients with complete celiac occlusion who undergo PDAA interventions.

Maximizing proximal seal zone in fenestrated endografting: Evolution in the approach to graft configuration.

OBJECTIVE: Fenestrated endografting for juxtarenal and pararenal abdominal aortic aneurysms affords the ability to seal stent grafts in normal aorta at and above the renal arteries. The Zenith fenestrated graft (ZFEN; Cook Medical, Bloomington, Ind) is custom-made to surgeon specifications, subject to certain manufacturing limitations. The most common configuration in the pivotal trial and in commercial use after approval has been as a scallop for the superior mesenteric artery (SMA) and two small fenestrations for the renal arteries (configuration A). An alternative configuration to maximize the seal zone length, consisting of a large fenestration for the SMA and two small fenestrations for the renal arteries (configuration B) has been routinely adopted at our institutions to potentially prevent type IA endoleak. METHODS: The present retrospective cohort study examined 100 consecutive ZFEN grafts designed for patients at two university centers from 2012 through 2019. The proximal seal length, measured from the top of the graft to the beginning of the aneurysm, was determined from the preoperative computed tomography angiograms. Alternative configurations were evaluated to determine whether they would have provided a longer proximal seal length. RESULTS: The two most common configurations were B (n = 45) and A (n = 38). For the cases in which A had been chosen but B could have been built, 5.8 ± 1.9 mm of seal zone length was lost. For the cases in which B was chosen but A could have been built, 5.8 ± 2.8 mm of seal zone length was gained. Owing, in part, to the increased proximal seal length with configuration B, this configuration has been used more frequently in the past 4 years of the present study compared with the first four (53% vs 25%; P = .004). Of 95 patients who had completed surgery and follow-up, type IA endoleaks were observed in 12 (13%) on completion angiography, all of which had resolved on follow-up imaging without intervention. No SMA was compromised by misalignment of the large fenestration in configuration B. CONCLUSIONS: A significantly longer proximal seal length can be obtained using a ZFEN with a large fenestration for the SMA and two small fenestrations for the renal arteries. Whenever possible, surgeons should consider this configuration to maximize the proximal seal length and potentially reduce the risk of proximal endoleak. An additional advantage of this approach is that stenting of the SMA to prevent shuttering will be unnecessary or impossible, making the procedure more technically facile.

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.

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.

Is Routine Postoperative Anticoagulation Necessary in All Patients after First Rib Resection for Paget-Schroetter Syndrome?

BACKGROUND: Definitive treatment of Paget-Schroetter syndrome (PSS) involves first rib resection (FRR), division of the anterior scalene muscle, and resection of the subclavius muscle. This is a single-institution experience with PSS, according to a treatment algorithm of preoperative venogram (accompanied by lysis and percutaneous mechanical thrombectomy as needed) followed by transaxillary FRR. In the later period of this experience, patients have often been discharged on aspirin only, with no plan for anticoagulation postoperatively. We sought to evaluate outcomes in light of this experience and these practice patterns. METHODS: Between 2007 and 2018, 125 transaxillary FRRs were performed in 123 patients. All patients presented with documented venous thrombosis, underwent diagnostic venography and-if indicated-lysis and percutaneous mechanical thrombectomy (VPT) before FRR. The patient was not offered FRR if the vein could not be crossed with a wire and patency was not re-established during percutaneous treatment. The experience was divided into early (before 2012, n = 50) and late (n = 75) periods. RESULTS: Mean patient age was 28.4 (12-64 years) years. Of the cohort, 33 were high-level competitive athletes, 13 presented with documented pulmonary embolism in addition to local symptoms, and 3 had a cervical rib fused to the first rib. Patients underwent FRR a median of 50 (4 days to 18 years) days after their initial symptoms, and a median of 22 (1 day to 9 months) days after their percutaneous intervention. Postoperative VPT was required in 23 patients and performed a median of 5 (1-137 days) days postoperatively; in 19 of these patients, postoperative VPT was required for postoperative re-thrombosis, whereas in 4 patients, postoperative VPT was planned before FRR due to vein stenosis or residual thrombus. All these patients were prescribed postoperative anticoagulation. No operative venous reconstruction or bypass was performed. Median follow-up time after FRR was 242 days; at last follow-up, 98.4% (123/125) of axillosubclavian veins were patent by duplex ultrasound (and all those patients were asymptomatic). Postoperative anticoagulation was less frequently prescribed in the late experience, with no difference in the rate of early re-thrombosis or follow-up patency. CONCLUSIONS: This experience demonstrates 98.4% patency at last follow-up with standard preoperative percutaneous venography and intervention, transaxillary FRR, and postoperative endovascular re-intervention only in cases with persistent symptoms, stenosis, or re-thrombosis. Patients presenting with both acute and chronic PSS did not require surgical venous reconstruction. In the later experience, patients frequently have not been anticoagulated postoperatively. Advantages of this algorithm include the following: (1) the cosmetic benefits of the transaxillary approach, (2) the preoperative assessment of the ability to recanalize the vein to determine which patients will benefit from surgery, (3) the capacity to use thrombolysis preoperatively, and (4) potential elimination of the risk and inconvenience of postoperative anticoagulation.

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.

Impact of acute postoperative limb ischemia after cardiac and thoracic aortic surgery.

OBJECTIVE: Acute limb ischemia (ALI) is the cause of significant morbidity and mortality. Although ALI after cardiac surgery is associated with high rates of morbidity and mortality, there are no robust, controlled analyses of the risk factors and outcomes of ALI in this setting. We aimed to identify risk factors for and to delineate outcomes after ALI in patients undergoing cardiac surgery. METHODS: We performed a retrospective review of prospectively collected data on patients undergoing cardiac surgery at our institution between 2002 and 2012. RESULTS: Between 2002 and 2012, there were 11,343 patients who underwent major open cardiac surgery, with 156 cases of ALI for an incidence of 1.4%. In a multivariable model, significant risk factors for ALI included body surface area (odds ratio [OR], 0.41; 95% confidence interval [CI], 0.18-0.92), current smoking status (OR, 2.2; 95% CI, 1.3-3.7), peripheral arterial disease (OR, 2.5; 95% CI, 1.6-3.7), nonelective operative status (OR, 1.9-5.0; 95% CI, 1.2-19.7), use of extracorporeal membrane oxygenation (OR, 5.6; 95% CI, 2.5-11.6) or intra-aortic balloon pump (OR, 4.7; 95% CI, 2.9-7.5), and valve operation (OR, 2.1; 95% CI, 1.1-4.0). There were 105 (67%) patients who developed ALI who required an operation, and 27 (17%) required an amputation on the index admission. ALI was associated with a significant reduction in long-term survival (hazard ratio, 3.72; 95% CI, 2.97-4.65; P < .0001). CONCLUSIONS: ALI is associated with significant morbidity and mortality, and it is also associated with reduced long-term survival. Those patients with the risk factors described require extra vigilance to limit the risk of ALI and should be managed in accordance with the patient's overall clinical condition and goals of care.

National trends in admissions, repair, and mortality for thoracic aortic aneurysm and type B dissection in the National Inpatient Sample.

OBJECTIVE: The advent of endovascular repair for both thoracic aortic aneurysm and type B dissection has transformed the management of these disease processes. This study was undertaken to better define, compare, and contrast the national trends in hospital admissions, invasive treatments, and inpatient mortality of patients with thoracic aortic aneurysm and type B dissection in the National Inpatient Sample. METHODS: The cohort was derived from International Classification of Diseases, Ninth Revision diagnosis codes for thoracic aortic dissection and thoracic aortic or thoracoabdominal aortic aneurysm. Patients receiving type A dissection or ascending aortic repair during their index admission were excluded using International Classification of Diseases, Ninth Revision procedure codes. A total of 155,187 patients were available for analysis from 2000 to 2012. RESULTS: Admissions for thoracic aortic aneurysm outnumbered the admissions for type B dissection (69.8% vs 30.2%; P < .001), and the number of admissions for aneurysm grew more rapidly during this time (132% vs 63%; P < .001). Thoracic endovascular aortic repair (TEVAR) for aneurysm experienced an increase in 2005, concordant with Food and Drug Administration approval of TEVAR for thoracic aortic aneurysm indication, then superseded open repair for thoracic aortic aneurysm from 2006 onward. Despite this, the rate of thoracic aortic aneurysm repair has remained relatively stable over time. TEVAR for dissection increased in 2006, superseded open repair in 2010, and continues to account for 50.5% of all dissection repairs. Overall, the number of type B dissection repairs has increased (P < .001), over and above the increase in number of admissions for type B dissection. Despite the increased trends of utilization of TEVAR for both aneurysm and type B dissection, the overall in-hospital mortality rate among patients admitted for either disease state has decreased steadily over time (P < .001). CONCLUSIONS: Whereas admissions for thoracic aortic aneurysm disease have increased over time, the rate of aneurysm repair has been stable, although TEVAR has supplanted a proportion of open repairs. In contrast, whereas admissions for type B dissection have experienced a more modest increase, there has been a disproportionate increase in type B dissection repair, largely due to increased use of TEVAR. These results show embracing of endovascular technology for dissection through expansion of indication. Despite the increase in rate of repair for type B dissection, inpatient mortality rate was reduced in both aneurysm and dissection patients, influenced by appropriate selection of patients for intervention.

Insight into the cerebral hyperperfusion syndrome following carotid endarterectomy from the national Vascular Quality Initiative.

BACKGROUND: Cerebral hyperperfusion syndrome (CHS), characterized by severe ipsilateral headache, seizures, and intracranial hemorrhage, is a rare, poorly understood complication that can be fatal following carotid endarterectomy (CEA). The purpose of the study was to determine the factors associated with CHS as captured in the Vascular Quality Initiative. METHODS: Analysis was conducted on 51,001 procedures captured from the CEA module of the Vascular Quality Initiative from 2003 to 2015. Preoperative, operative, and postoperative variables were considered for inclusion in logistic regression analyses to determine possible associations with CHS. The relative contribution of each variable to the overall model was determined using dominance analysis. RESULTS: The mean age was 70.2 ± 9.4 years; there were 39.6% female patients, 93.1% of white race, with 29.6% of CEAs being performed for symptomatic status. The overall rate of CHS was 0.18% (n = 94), with 55.1% occurring in asymptomatic and 44.9% occurring in symptomatic patients with an associated mortality rate of 38.2%. Multivariable analysis including preoperative variables showed that female gender (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.09-2.51; P = .019), <1 month major ipsilateral stroke (OR, 5.36; 95% CI, 2.35-12.22; P < .001), coronary artery disease (OR, 1.77; 95% CI, 1.15-2.71; P = .009), and contralateral stenosis ≥70% (OR, 1.54; 95% CI, 1.00-2.36; P = .050) were independently associated with CHS and that <1 month major stroke was the most important contributor to the model. With the additional inclusion of operative and postoperative variables, female gender (OR, 1.75; 95% CI, 1.14-2.67; P = .010), <1 month ipsilateral major stroke (OR, 3.20; 95% CI, 1.32-7.74; P = .010), urgency (OR, 2.25; 95% CI, 1.38-3.67; P = .001), re-exploration (OR, 2.98; 95% CI, 1.27-6.97; P = .012), postoperative hypertension (OR, 4.09; 95% CI, 2.65-6.32; P < .001), postoperative hypotension (OR, 3.21; 95% CI, 1.97-5.24; P < .001), dysrhythmias (OR, 3.23; 95% CI, 1.64-6.38; P = .001), and postoperative myocardial infarction (OR, 2.84; 95% CI, 1.21-6.67; P = .017) were significantly associated with CHS, with postoperative blood pressure lability and cardiac complications having the strongest associations with CHS. CONCLUSIONS: The risk of CHS was highest in female patients and in those with a recent major stroke, coronary artery disease, and contralateral stenosis ≥70%. In addition, in adjusting for operative and postoperative variables, CHS was most significantly associated with postoperative blood pressure lability and cardiac complications. These data lend insight into a high-risk population for this devastating complication.

Management of Difficult Access during Endovascular Aneurysm Repair.

BACKGROUND: To describe a large single-institutional experience in managing challenging access situations during endovascular aneurysm repair (EVAR). METHODS: Data from all patients undergoing EVAR at a tertiary academic medical center between 2009 and 2013 were collected retrospectively, including demographics, size of iliac arteries, type of device used, approach to managing difficult access (DA), and outcomes. The median follow-up was 38 months. DA was defined as iliac arteries with a diameter of less than 7 mm bilaterally. Fenestrated and snorkel repairs were excluded. RESULTS: Of 400 EVARs performed during the study period, 191 (48%) were done in patients with DA. Of the DA patients, 35 (18.3%) underwent 42 adjuncts before the introduction of the main body device: including 15 dilators, 11 balloon angioplasties, 9 aortouniiliac devices, 3 SoloPath sheaths, 1 retroperitoneal cutdown, and 3 iliac stents. In another 29 patients, iliac stents were used to correct stenoses or kinks in the limbs after EVAR devices were deployed. The average diameter of the iliac artery used to deliver main body component was 4.6 mm in the group of patients requiring adjuncts and 5.4 mm in the remainder of the patients with small iliac arteries (P = 0.008). The median size of the main body device was 28 mm. Two cases were aborted due to inability to deliver the device. Other complications included 7 (3.6%) iliac ruptures, 3 (1.6%) instances of limb ischemia, and 5 (2.6%) patients needed early reoperation (within 30 days). Two patients (1%) had type I endoleaks at the conclusion of EVAR. During follow-up, 12 (6.3%) patients required EVAR revisions. Seven patients (3.6%) had limb thrombosis which occurred only in patients who did not have adjective procedures during the initial EVAR. Limb thrombosis and rate of revisions in patients with DA were not significantly different from the rates observed in non-DA patients. Perioperative mortality after elective repairs was 1.6% in DA patients and 0% in non-DA patients (P = 0.12). CONCLUSIONS: EVAR can be successfully performed in patients with bilateral small iliac arteries. Adjunctive procedures might increase the technical success rate of EVAR in these patients and should definitely be considered in patients with iliac arteries less than 5 mm in diameter. Next generation and "low-profile" devices might minimize the need for adjunctive procedures and facilitate EVAR in these patients.

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.

The Associations between Peripheral Artery Disease and Physical Outcome Measures in Men and Women with Chronic Kidney Disease.

BACKGROUND: Peripheral artery disease (PAD) is highly prevalent and associated with significant morbidity and mortality, but sex-based differences are incompletely understood. We sought to define the associations between PAD and physical outcome measures and to determine if these associations differed by sex in the Chronic Renal Insufficiency Cohort. METHODS: Among 3,543 participants, we assessed the cross-sectional relationship between PAD severity defined by ankle-brachial index; and (1) physical activity (metabolic equivalent [MET]-hr/wk), (2) walking pace (slow versus medium and/or fast), and (3) physical function (12-item Short Form Health Survey [SF-12]) at baseline. RESULTS: In a multivariable linear regression model, PAD severity was not associated with physical activity defined by total MET-hr per wk in men or women (P = 0.432). However, PAD severity was significantly associated with walking activity (P = 0.037), although this relationship did not differ by sex (P = 0.130). Similarly, PAD severity was significantly associated with walking pace (P < 0.001), although this relationship did not differ by sex (P = 0.086). In contrast, there was an independent association between PAD severity and SF-12 (P = 0.018), with a significant interaction by sex (P < 0.001). CONCLUSIONS: These data suggest that tools used to evaluate the functional consequences of PAD should focus on walking activity and walking pace, as well as physical function, where sex-specific associations should be accounted for.

Aggressive venous thromboembolism prophylaxis reduces VTE events in vascular surgery patients.

OBJECTIVE: Venous thromboembolism (VTE) is a potentially preventable complication following surgery. There is variation with regard to the most effective mode of prophylaxis. We sought to determine if an aggressive approach to VTE prophylaxis would reduce VTE rates on the inpatient vascular surgical service. METHODS: Vascular inpatients from a single institution from July 2010 to March 2013 were included in the analysis. A protocol for VTE prophylaxis was implemented on the inpatient vascular surgical service in November 2011. This included subcutaneous (SQ) heparin initiation within 24 h of admission unless deemed inappropriate by the attending, as well as intermittent compression devices (ICD) and compression stockings (CS). The rate of VTE was compared prior to and following the intervention. Patients were compared using AHRQ comorbidity categories, APR-DRG severity of illness, insurance status, and principle procedure. T-tests were used to compare continuous variables and chi-square analysis used to compare categorical variables. RESULTS: There were 1483 vascular patients in the pre-intervention group and 1652 patients in the post-intervention group. The rate of pharmacologic prophylaxis was 52.57% pre-intervention compared to 69.33% post-intervention (p < 0.001). The rate of pharmacologic or mechanical prophylaxis was 91.76% pre-intervention compared to 93.10% post-intervention (p = 0.54). The overall rate of VTE prior to the intervention was 1.49% compared to after intervention which was 0.38% (p = 0.033). The DVT rate prior to intervention was 1.09% vs 0.189% after intervention (p = 0.0214). The rate of pulmonary embolism trended towards a significant reduction with the intervention (0.681% vs 0.189%, p = 0.095). There were no statistically significant differences in patient groups based on gender, comorbidity category, severity of illness, or insurance type. CONCLUSIONS: The overall rate of VTE was reduced by 75% after the initiation of a standard protocol for pharmacologic VTE prophylaxis. These findings justify an aggressive approach to VTE prophylaxis in vascular surgery patients.

Comparison of risk factors for length of stay and readmission following lower extremity bypass surgery.

OBJECTIVE: Recent initiatives to improve health care quality have focused attention on length of stay (LOS) and readmission rates for surgical patients, yet these two outcomes may be inversely related. This study was designed to elucidate the risk factors for both outcomes and to clarify the relationship between them in patients undergoing lower extremity bypass (LEB). METHODS: Peripheral arterial disease (PAD) patients who underwent LEB were identified from the 2007-2010 California State Inpatient Database. LOS and risk factors were analyzed using Poisson regression. Risk factors for 30-day readmission were analyzed using logistic regression. RESULTS: There were 6307 patients who underwent LEB, and 1291 (20%) were readmitted. The average index LOS was 8.3 days for those who were readmitted and 5.5 days for those who were not (P < .0001) and was an independent risk factor for 30-day readmission. The significant factors with the largest effect estimates for increased LOS reflected disease severity and postoperative complications: emergency department admission; advanced PAD; postoperative pneumonia, respiratory failure, urinary tract infection, wound/graft infection, graft complication, and discharge to a nursing facility. Independent predictors of readmission, other than LOS, reflected underlying patient factors: advanced PAD, chronic lung disease, diabetes, renal failure, postoperative congestive heart failure, and discharge status. Age, Medicaid or private insurance, and low income were protective. Of the 1291 readmissions, 453 (35%) were for definitive complications. CONCLUSIONS: In patients undergoing LEB, LOS is primarily associated with the occurrence of postoperative complications, whereas 30-day readmission is largely explained by underlying patient illness. Additionally, increased LOS is an independent risk factor for readmission. These findings suggest that efforts to reduce both LOS and readmission will be complementary. Furthermore, they support the notion that both LOS and 30-day readmission rates should be risk-adjusted.

Use of computational fluid dynamics studies in predicting aneurysmal degeneration of acute type B aortic dissections.

OBJECTIVE: Whereas uncomplicated acute type B aortic dissections are often medically managed with good outcomes, a subset develop subacute or chronic aneurysmal dilation. We hypothesized that computational fluid dynamics (CFD) simulations may be useful in identifying patients at risk for this complication. METHODS: Patients with acute type B dissection complicated by rapidly expanding aortic aneurysms (N = 7) were compared with patients with stable aortic diameters (N = 7). Three-dimensional patient-specific dissection geometries were generated from computed tomography angiography and used in CFD simulations of pulsatile blood flow. Hemodynamic parameters including false lumen flow and wall shear stress were compared. RESULTS: Patients with rapid aneurysmal degeneration had a growth rate of 5.3 ± 2.7 mm/mo compared with those with stable aortic diameters, who had rates of 0.2 ± 0.02 mm/mo. Groups did not differ in initial aortic diameter (36.1 ± 2.9 vs 34.4 ± 3.6 mm; P = .122) or false lumen size (22.6 ± 2.9 vs 20.2 ± 4.5 mm; P = .224). In patients with rapidly expanding aneurysms, a greater percentage of total flow passed through the false lumen (78.3% ± 9.3% vs 56.3% ± 11.8%; P = .016). The time-averaged wall shear stress on the aortic wall was also significantly higher (12.6 ± 3.7 vs 7.4 ± 2.8 Pa; P = .028). CONCLUSIONS: Hemodynamic parameters derived from CFD simulations of acute type B aortic dissections were significantly different in dissections complicated by aneurysm formation. Thus, CFD may assist in predicting which patients may benefit from early stent grafting.

Local wall thickness in finite element models improves prediction of abdominal aortic aneurysm growth.

OBJECTIVE: Growing evidence suggests that peak wall stress (PWS) derived from finite element analysis (FEA) of abdominal aortic aneurysms (AAAs) predicts clinical outcomes better than diameter alone. Prior models assume uniform wall thickness (UWT). We hypothesize that the inclusion of locally variable wall thickness (VWT) into FEA of AAAs will improve its ability to predict clinical outcomes. METHODS: Patients with AAAs (n = 26) undergoing radiologic surveillance were identified. Custom MATLAB algorithms generated UWT and VWT aortic geometries from computed tomography angiography images, which were subsequently loaded with systolic blood pressure using FEA. PWS and aneurysm expansion (as a proxy for rupture risk and the need for repair) were examined. RESULTS: The average radiologic follow-up time was 22.0 ± 13.6 months and the average aneurysm expansion rate was 2.8 ± 1.7 mm/y. PWS in VWT models significantly differed from PWS in UWT models (238 ± 68 vs 212 ± 73 kPa; P = .025). In our sample, initial aortic diameter was not found to be correlated with aneurysm expansion (r = 0.26; P = .19). A stronger correlation was found between aneurysm expansion and PWS derived from VWT models compared with PWS from UWT models (r = 0.86 vs r = 0.58; P = .032 by Fisher r to Z transformation). CONCLUSIONS: The inclusion of locally VWT significantly improved the correlation between PWS and aneurysm expansion. Aortic wall thickness should be incorporated into future FEA models to accurately predict clinical outcomes.

Trends in Endovascular Aortic Aneurysm Repair Length of Stay over a Decade at a Tertiary Academic Institution.

BACKGROUND: Length of stay (LOS) is used as a quality metric to reduce cost and improve value of delivery of care. We sought to analyze trends in endovascular aortic aneurysm repair (EVAR) LOS at a tertiary academic institution over the last decade. METHODS: A retrospective review of prospectively collected data was performed. Infrarenal EVARs from 2001 to 2013 were divided into 3 groups: group I (2001-2004), EVARs were performed as part of clinical trials; group II (2005-2008), EVARs were referred to a tertiary referral center with the most experience with EVAR; group III (2009-2013), EVARs were referred to academic institutions in the presence of severe patient comorbidities. Trends in LOS and correlation with severity of illness (SOI) as based on All Patient Refined Diagnosis Related Groups and admission and/or disposition status were analyzed. LOS index (LOSI) at our institution was then compared with University HealthSystem Consortium (UHC) Hospitals over the past 3 years. RESULTS: A total of 1,265 EVARs were performed during this time period: 325 in group I, 547 in group II, and 393 in group III. The median LOS was 4 days (inter quartile range [IQR], 2-6) vs. 3 days (IQR, 2-5) ± 0.28 vs. 4 days (IQR, 3-7), respectively (P < 0.01). Although moderate SOI was fairly constant over time (P = 0.66), major and/or extreme SOI constituted a greater proportion of patients in group I, was reduced in group II, and was again increased in group III, P < 0.01. The complication rate paralleled this pattern (group I, 15.2%; group II, 8.6%; group III, 10.4%; P = 0.02). The percentage of patients discharged to nursing home and/or rehab was 5.7% in group I, 8.2% in group II, 11.5% in group III (P = 0.03). Cases that were performed urgently and/or emergently increased over time: 11.6% in group I, 14.9% in group II, 21.6% in group III (P = 0.01). The risk-adjusted LOSI at our institution was significantly greater (1.25) when compared with UHC hospitals (0.75). CONCLUSIONS: Our study suggests a relationship between time period of EVAR, SOI, complications, admission status, and LOS. Attention to these trends could be used to decrease LOS in an increasingly complex patient population.

Impact of wall thickness and saccular geometry on the computational wall stress of descending thoracic aortic aneurysms.

BACKGROUND: Wall stress calculated using finite element analysis has been used to predict rupture risk of aortic aneurysms. Prior models often assume uniform aortic wall thickness and fusiform geometry. We examined the effects of including local wall thickness, intraluminal thrombus, calcifications, and saccular geometry on peak wall stress (PWS) in finite element analysis of descending thoracic aortic aneurysms. METHODS AND RESULTS: Computed tomographic angiography of descending thoracic aortic aneurysms (n=10 total, 5 fusiform and 5 saccular) underwent 3-dimensional reconstruction with custom algorithms. For each aneurysm, an initial model was constructed with uniform wall thickness. Experimental models explored the addition of variable wall thickness, calcifications, and intraluminal thrombus. Each model was loaded with 120 mm Hg pressure, and von Mises PWS was computed. The mean PWS of uniform wall thickness models was 410 ± 111 kPa. The imposition of variable wall thickness increased PWS (481 ± 126 kPa, P<0.001). Although the addition of calcifications was not statistically significant (506 ± 126 kPa, P=0.07), the addition of intraluminal thrombus to variable wall thickness (359 ± 86 kPa, P ≤ 0.001) reduced PWS. A final model incorporating all features also reduced PWS (368 ± 88 kPa, P<0.001). Saccular geometry did not increase diameter-normalized stress in the final model (77 ± 7 versus 67 ± 12 kPa/cm, P=0.22). CONCLUSIONS: Incorporation of local wall thickness can significantly increase PWS in finite element analysis models of thoracic aortic aneurysms. Incorporating variable wall thickness, intraluminal thrombus, and calcifications significantly impacts computed PWS of thoracic aneurysms; sophisticated models may, therefore, be more accurate in assessing rupture risk. Saccular aneurysms did not demonstrate a significantly higher normalized PWS than fusiform aneurysms.