William D. Jordan

Rupture rate of large abdominal aortic aneurysms in patients refusing or unfit for elective repair

CONTEXTnAmong patients with abdominal aortic aneurysm (AAA) who have high operative risk, repair is usually deferred until the AAA reaches a diameter at which rupture risk is thought to outweigh operative risk, but few data exist on rupture risk of large AAA.nnnOBJECTIVEnTo determine the incidence of rupture in patients with large AAA.nnnDESIGN AND SETTINGnProspective cohort study in 47 Veterans Affairs medical centers.nnnPATIENTSnVeterans (n = 198) with AAA of at least 5.5 cm for whom elective AAA repair was not planned because of medical contraindication or patient refusal. Patients were enrolled between April 1995 and April 2000 and followed up through July 2000 (mean, 1.52 years).nnnMAIN OUTCOME MEASUREnIncidence of AAA rupture by strata of initial and attained diameter.nnnRESULTSnOutcome ascertainment was complete for all patients. There were 112 deaths (57%) and the autopsy rate was 46%. Forty-five patients had probable AAA rupture. The 1-year incidence of probable rupture by initial AAA diameter was 9.4% for AAA of 5.5 to 5.9 cm, 10.2% for AAA of 6.0 to 6.9 cm (19.1% for the subgroup of 6.5-6.9 cm), and 32.5% for AAA of 7.0 cm or more. Much of the increased risk of rupture associated with initial AAA diameters of 6.5-7.9 cm was related to the likelihood that the AAA diameter would reach 8.0 cm during follow-up, after which 25.7% ruptured within 6 months.nnnCONCLUSIONnThe rupture rate is substantial in high-operative-risk patients with AAA of at least 5.5 cm in diameter and increases with larger diameter.

Predictors of early aortic neck dilatation after endovascular aneurysm repair with EndoAnchors

Objective: Dilatation of the aorta within the proximal neck after endovascular aneurysm repair (EVAR) can be associated with late endoleaks and migration. This study was designed to identify predictors of early neck dilation in patients undergoing EVAR with Heli‐FX EndoAnchors (Medtronic, Santa Rosa, Calif) measured perioperatively to 1 year at different longitudinal levels of neck length. Methods: The study group of Aneurysm Treatment Using the Heli‐FX Aortic Securement System (ANCHOR) comprises 257 consecutive patients prospectively enrolled between April 2012 and September 2014 undergoing EVAR with Heli‐FX EndoAnchor implantation at 38 investigational sites. Only patients undergoing EndoAnchor implantation at the time of the initial EVAR were included (primary treatment arm). Aortic diameter was measured at the suprarenal level and at three levels within the proximal neck. Neck dilatation was assessed in 209 patients with adequate computed tomography imaging at baseline and 1 month and in 62 patients at 1 month and 1 year (mean, 11.9 ± 4.0 months). Multivariable analyses were performed to identify independent predictors of perioperative (baseline to 1 month) and early postoperative (1 month to 1 year) aortic dilation at each level; analyses included 6 candidate variables, 6 clinical, and 14 anatomic run in eight models (one at each of the four aortic levels for both time frames). Results: The mean aortic neck dilation at 1 month was 0.2 ± 1.7 mm, 0.7 ± 2.2 mm, and 0.9 ± 3.6 mm at 0 mm, 5 mm, and 10 mm below the lowest renal artery, and 0.0 ± 1.5 mm at the suprarenal level. From 1 month to 1 year, neck dilatation was 0.5 ± 1.6 mm, 0.4 ± 1.5 mm, 0.2 ± 1.8 mm, and −0.3 ± 1.1 mm at the same four levels, respectively. Dilatation of ≥3 mm at level 5 mm distal to the lowest renal artery was observed in 26 patients (12.5%) from preoperative to 1 month and in 5 patients (8.1%) between 1 month and 1 year. Multivariable regression identified several variables predictive of perioperative (preoperative to 1 month) neck dilatation: baseline neck diameter, mural calcium (protective), and endografts with a suprarenal stent. Neck dilatation between 1 month and 1 year was associated with baseline neck diameter, neck length (protective), neck angulation, device oversizing, number of EndoAnchors implanted (protective), and endografts with a suprarenal stent. Conclusions: Aortic diameter and graft oversizing appear to be independent risk factors for early aortic neck dilatation. EndoAnchors have a protective effect on neck dilatation at their usual level of deployment.

The Impact of Thoracic Endovascular Aortic Repair on Long-Term Survival in Type B Aortic Dissection

BACKGROUNDnCurrently, optimal medical therapy is first-line therapy for uncomplicated acute type B aortic dissection (aTBAD) despite poor long-term outcomes. This study examines the impact of thoracic endovascular aortic repair (TEVAR) in the acute and chronic phases on short-term and long-term survival of patients presenting with aTBAD.nnnMETHODSnA review of the Emory aortic database from 2000 to 2016 identified 398 patients diagnosed with aTBAD. At index hospitalization, complicated patients underwent TEVAR (aTEVAR [thoracic endovascular aortic repair in the acute phase], nxa0= 80) and uncomplicated patients received optimal medical therapy (nxa0= 318). Uncomplicated patients were divided into subgroups based on final treatment: (1) TEVAR (cTEVAR [thoracic endovascular aortic repair in the chronic phase], nxa0= 87); (2) open aortic replacement (nxa0= 59); and (3) optimal medical therapy (nxa0= 172). Kaplan-Meier curves assessed long-term mortality.nnnRESULTSnThe mean age of patients was 57 ± 12 years. In the uncomplicated group, 146 patients (45.9%) patients failed optimal medical therapy and underwent open repair (nxa0= 59) or endovascular repair (cTEVAR, nxa0= 87) repair in the chronic phase. Inhospital mortality was 5% and equivalent between complicated and uncomplicated aTBAD groups at index hospitalization. For patients requiring intervention, mortality and renal failure were highest for open patients (16.9%, p < 0.01, and 10.2%, pxa0=xa00.05, respectively), and stroke was highest among aTEVAR patients (7.5%, p < 0.01). The incidence of paraparesis and paraplegia was low and equivalent among the three groups. Despite a higher mortality risk at presentation, there was a trend toward improved long-term survival among complicated aTBAD patients (complicated 84.1% versus uncomplicated 58.9%, pxa0= 0.17). Intervention-free survival at 5 and 10 years for all uncomplicated patients was 50.4% and 32.9%, respectively.nnnCONCLUSIONSnThe treatment of uncomplicated aTBAD with optimal medical therapy results in a high incidence of surgical intervention and poor long-term survival. At the index hospitalization, TEVAR may confer a survival advantage and serve as optimal therapy for complicated and uncomplicated aTBAD patients.

The Occluded Renal Artery: An Ongoing Surgical Challenge

Nephrectomy and revascularization are currently the preferred options in the management of the chronically occluded renal artery in patients with renovascular hypertension or renal insufficiency. We review our experience with these two options including early and late functional outcome. Between December 1982 and August 1993, chronic occlusion of the main renal artery was documented in 30 patients. Patients were categorized with respect to surgical intervention: group I underwent nephrectomy (on the occluded side) plus contralateral revascularization and group II underwent revascularization of the occluded renal artery. The median age at the time of operative intervention was 63 years; 53% of the patients were women and 47% were men. Hypertension was poorly controlled (>-3 medications) in 19 patients, and the preoperative serum creatinine level was > 1.8 mg/dl in 24 patients (mean 2.6±1.4 mg/dl). There were 16 patients in group I and 14 patients in group II, and there were no perioperative deaths. Estimated glomerular filtration rate (>-7 days after operation) was either unchanged or improved in 15 of 16 patients in group I and in 13 of 14 in group II, one of whom became dialysis dependent. Follow-up data were available for 25 of 30 (83%) patients (mean 45 months; range 1 to 108 months). Excluding one early failure, 10 of 13 patients in group I and 7 of 11 in group II did not have end-stage renal disease at last follow-up. Overall, hypertension was cured or improved in 16 of 21 patients. Revascularization as the preferred method of treatment of the occluded renal artery offers the prospect of renal salvage. Nonetheless, in the majority of properly selected patients, adequate renal function may be sustained and satisfactory blood pressure control achieved after nephrectomy with contralateral revascularization.

High Hemoglobin A1c Associated with Increased Adverse Limb Events in Peripheral Arterial Disease Patients Undergoing Revascularization

Objective Diabetes and peripheral arterial disease (PAD) are independently associated with increased risk of amputation. However, the effect of poor glycemic control on adverse limb events has not been studied. We examined the effects of poor glycemic control (high hemoglobin A1c level) on the risk of amputation and modified major adverse limb events (mMALEs) after lower extremity revascularization. Methods Patients undergoing PAD revascularization who had hemoglobin A1c (HbA1c) levels available within 6 months were identified in the Veterans Affairs database of 2003 to 2014 (N = 26,799). The diagnosis of preoperative diabetes mellitus (PreopDM) was defined using diabetes diagnosis codes and evidence of treatment. Amputation and mMALE risk was compared for HbA1c levels using Kaplan‐Meier analysis. Cox proportional hazards models were created to assess the effect of high HbA1c levels on amputation and mMALE (adjusted for age, gender, race, socioeconomic status, comorbidities, cholesterol levels, creatinine concentration, suprainguinal or infrainguinal procedure, open or endovascular procedure, severity of PAD, year of cohort entry, and medications) for all patients and stratified by PreopDM. Results High HbA1c levels were present in 33.2% of the cohort, whereas 59.9% had PreopDM. Amputations occurred in 4359 (16.3%) patients, and 10,580 (39.5%) had mMALE. Kaplan‐Meier curves showed the worst outcomes in patient with PreopDM and high HbA1c levels. In the Cox model, incremental HbA1c levels of 6.1% to 7.0%, 7.1% to 8.0%, and >8% were associated with 26% (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.15‐1.39), 53% (HR, 1.53; 95% CI, 1.37‐1.7), and 105% (HR, 2.05; 95% CI, 1.87‐2.26) higher risk of amputation, respectively. Similarly, the risk of mMALE also increased by 5% (HR, 1.05; 95% CI, 0.99‐1.11), 21% (HR, 1.21; 95% CI, 1.13‐1.29), and 33% (HR, 1.33, 95% CI, 1.25‐1.42) with worsening HbA1c levels of 6.1% to 7.0%, 7.1% to 8.0%, and >8%, respectively (vs HbA1c ≤6.0%). In stratified analysis by established PreopDM, the relative risk of amputation or mMALE was much higher with poor glycemic control (HbA1c >7.0%) in patients without PreopDM. Conclusions PAD patients with worse perioperative glycemic control have a significantly higher risk of amputation and mMALE. Incremental increases in HbA1c levels are associated with higher hazards of adverse limb outcomes independent of PreopDM status. Poor glycemic control (HbA1c >7.0%) in patients without a PreopDM diagnosis carries twice the relative risk of amputation and mMALE than in those with good glycemic control. These results suggest that screening of diabetic status and better management of glycemic control could be a target for improvement of perioperative and long‐term outcomes in PAD patients.

The Society for Vascular Surgery practice guidelines on follow-up after vascular surgery arterial procedures

ABSTRACT Although follow‐up after open surgical and endovascular procedures is generally regarded as an important part of the care provided by vascular surgeons, there are no detailed or comprehensive guidelines that specify the optimal approaches with regard to testing methods, indications for reintervention, and follow‐up intervals. To provide guidance to the vascular surgeon, the Clinical Practice Council of the Society for Vascular Surgery appointed an expert panel and a methodologist to review the current clinical evidence and to develop recommendations for follow‐up after vascular surgery procedures. For those procedures for which high‐quality evidence was not available, recommendations were based on observational studies, committee consensus, and indirect evidence. Recognizing that there are numerous published reports on the role of duplex ultrasound for surveillance of infrainguinal vein bypass grafts, the Society commissioned a systematic review and meta‐analysis on this topic. The panel classified the strength of each recommendation and the corresponding quality of evidence on the basis of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system: recommendations were graded either strong or weak, and the quality of evidence was graded high, moderate, or low. The resulting recommendations represent a wide variety of open surgical and endovascular procedures involving the extracranial carotid artery, thoracic and abdominal aorta, mesenteric and renal arteries, and lower extremity arterial revascularization. The panel also identified many areas in which there was a lack of high‐quality evidence to support their recommendations. This suggests that there are opportunities for further clinical research on testing methods, threshold criteria, and the role of surveillance as well as on the modes of failure and indications for reintervention after vascular surgery procedures.

Five-year outcomes of the PYTHAGORAS U.S. clinical trial of the Aorfix endograft for endovascular aneurysm repair in patients with highly angulated aortic necks

Objective: Early and midterm outcomes of the Prospective Aneurysm Trial: High Angle Aorfix Bifurcated Stent Graft (PYTHAGORAS) trial in patients with highly angulated aortic necks (≥60 degrees) have already been published and shown comparable outcomes to other endografts in normal anatomy. Herein, we present the long‐term outcomes of the PYTHAGORAS trial of Aorfix (Lombard Medical, Irvine, Calif) for patients with highly angulated aortic neck anatomy. Methods: The Aorfix endograft is a highly conformable nitinol/polyester device designed for transrenal fixation. The U.S. trial enrolled 218 patients and observed all patients at 1 month, 6 months, and 12 months and then annually for a total of 5 years. Endovascular aneurysm repair (EVAR)‐specific complications were compared between the standard‐angle (<60 degrees) and highly angulated (≥60 degrees) neck groups at 5 years using standard statistical methods. Kaplan‐Meier analysis was performed to evaluate the overall 5‐year survival and freedom from aneurysm rupture, aneurysm‐related mortality, and reintervention. Results: Of the 218 patients enrolled in the trial, there were 67 patients in the standard‐angle neck group (I) and 151 patients in the highly angulated neck group (II). Mean proximal neck angle was 45 degrees in group I vs 83 degrees in group II (P < .001). At 5 years, 87% of surviving patients were followed up. The 5‐year EVAR‐specific results showed no type I or type III endoleak in either group, 4% migration in group I vs 3% in group II, and 4% sac expansion in group I vs 15.0% in group II (P ≥ .27). The 5‐year freedom from all‐cause mortality was 69% (73% in group I vs 68% in group II; P = .43); from aneurysm‐related mortality, 96% (99% vs 95%; P = .44); from aneurysm rupture, 99% (99% vs 99%; P = 1.0); and from device‐related secondary intervention, 83% (88% vs 80%; P = .18). None of these differed between groups. Conclusions: The U.S. PYTHAGORAS trial of the Aorfix endograft is the first EVAR clinical trial to include a majority of highly angulated (≥60 degrees) infrarenal aortic necks and is the first to produce evidence after 5 years of implantation. Despite predictors of worse short‐ and long‐term outcomes, pertinent outcomes were better than or similar to those of trials with less severe anatomy. These results support the use of this “on‐label” endovascular option, particularly in patients with highly angulated aortic neck anatomy.

Awake Thoracic Endovascular Aneurysm Repair for Aortic Rupture: A Case Series

Thoracic endovascular aortic repair (TEVAR) has been proven to be the optimal therapy for patients with a ruptured descending thoracic aortic pathology. In these emergent settings, TEVAR provides a rapid delivery of treatment to an unstable patient with a lethal disease. Typically, the greatest challenge is maintaining hemodynamic stability until the time of graft deployment. In this report, we describe our technique of performing awake TEVAR for ruptured descending thoracic aortic disease.

Matched cohort comparison of endovascular abdominal aortic aneurysm repair with and without EndoAnchors

Objective: The objective of this study was to examine whether prophylactic use of EndoAnchors (Medtronic, Santa Rosa, Calif) contributes to improved outcomes after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms through 2 years. Methods: The Aneurysm Treatment Using the Heli‐FX Aortic Securement System Global Registry (ANCHOR) subjects who received prophylactic EndoAnchors during EVAR were considered for this analysis. Imaging data of retrospective subjects who underwent EVAR at ANCHOR enrolling institutions were obtained to create a control sample. Nineteen baseline anatomic measurements were used to perform propensity score matching, yielding 99 matched pairs. Follow‐up imaging of the ANCHOR and control cohorts was then compared to examine outcomes through 2 years, using Kaplan‐Meier survival analysis. Results: Freedom from type Ia endoleak was 97.0% ± 2.1% in the ANCHOR cohort and 94.1% ± 2.5% in the control cohort through 2 years (P = .34). The 2‐year freedom from neck dilation in the ANCHOR and control cohorts was 90.4% ± 5.6% and 87.3% ± 4.3%, respectively (P = .46); 2‐year freedom from sac enlargement was 97.0% ± 2.1% and 94.0% ± 3.0%, respectively (P = .67). No device migration was observed. Aneurysm sac regression was observed in 81.1% ± 9.5% of ANCHOR subjects through 2 years compared with 48.7% ± 5.9% of control subjects (P = .01). Cox regression analysis found an inverse correlation between number of hostile neck criteria met and later sac regression (P = .05). Preoperative neck thrombus circumference and infrarenal diameter were also variables associated with later sac regression, although not to a significant degree (P = .10 and P = .06, respectively). Control subjects with thrombus were significantly less likely to experience later sac regression than those without thrombus (6% and 43%, respectively; P = .001). In ANCHOR subjects, rate of regression was not significantly different in subjects with or without thrombus (33% and 36%, respectively; P = .82). Control subjects with wide aortic necks (>28 mm) were observed to experience sac regression at a lower rate than subjects with smaller diameter necks (10% and 44%, respectively; P = .004). Wide neck and normal neck subjects implanted with EndoAnchors experienced later sac regression at roughly equivalent rates (44% and 33%, respectively; P = .50). Conclusions: In propensity‐matched cohorts of subjects undergoing EVAR, the rate of sac regression in subjects treated with EndoAnchors was significantly higher. EndoAnchors may mitigate the adverse effect of wide infrarenal necks and neck thrombus on sac regression, although further studies are needed to evaluate the long‐term effect of EndoAnchors.

Contemporary evaluation of mortality and stroke risk after thoracic endovascular aortic repair

Objective: During the past decade, thoracic endovascular aortic repair (TEVAR) has increased as a treatment option for a variety of aortic pathologic processes. Despite this rise in the use of thoracic stent grafts, real‐world outcomes from a robust, adjudicated, contemporary data set have yet to be reported. Previous studies have shown periprocedural mortality rates between 1.5% and 9.5% and procedure‐related stroke rates of 2.3% to 8.2%. With advances in device engineering and increased experience of physicians, we hypothesized that the rates of these complications would be reduced in a more recent sample set. The purpose of this study was to determine current rates of mortality and stroke after TEVAR, to identify risk factors that contribute to 30‐day mortality, and to develop a simple scoring system that allows risk stratification of patients undergoing TEVAR. Methods: We examined the 30‐day mortality rate after TEVAR using the 2013 to 2014 American College of Surgeons National Surgical Quality Improvement Program database. Patients undergoing TEVAR for all aortic disease were identified using procedure codes. Bivariate analyses were performed to evaluate the association of preoperative, intraoperative, and postoperative variables with 30‐day mortality, followed by multivariable logistic analysis using preoperative variables only, with P < .10 as the criterion for model entry. The predictive logistic model was internally validated by cross‐validation. Variables included in the multivariable model were used to develop a risk score. Results: There were 826 patients included. The 30‐day mortality and stroke rates were 7.63% (n = 63) and 4.5% (n = 37), respectively. In regression analysis, mortality was independently associated with age ≥80 years (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.25‐4.31), emergency case (OR, 2.61; 95% CI, 1.39‐4.90), American Society of Anesthesiologists classification >3 (OR, 2.89; 95% CI, 1.34‐6.24), transfusion >4 units in the 72 hours before surgery (OR, 2.86; 95% CI, 1.30‐6.28), preoperative creatinine concentration ≥1.8 mg/dL (OR, 2.07; 95% CI, 1.05‐4.08), and preoperative white blood cell count ≥12 × 109/L (OR, 2.65; 95% CI, 1.41‐4.96). Incorporating these factors, a 6‐point risk score was generated and demonstrated high predictability for overall 30‐day mortality. Conclusions: Recent data from a national, retrospective data set demonstrate that high perioperative mortality and stroke rates have persisted during the last decade. The risk score derived from this data set is simple and convenient and serves as a prognostic tool in the preoperative risk stratification of patients being evaluated for TEVAR.