David Dexter

A case-matched validation study of anatomic severity grade score in predicting reinterventions after endovascular aortic aneurysm repair

BACKGROUND In 2002, the Society for Vascular Surgery created the anatomic severity grading (ASG) score to classify abdominal aortic aneurysms (AAAs). Our objective was to identify the predictive capability and cutoff value of preoperative ASG score for reintervention after endovascular aneurysm repair (EVAR). METHODS We completed a retrospective review of AAA patients treated with elective EVAR from 2007 through 2011. Patients who had reinterventions as well as preoperative M2S (M2S Inc, West Lebanon, NH) three-dimensional reconstructions were identified and compared with a case-matched control group of patients without reintervention. ASG component scores (neck, aortic, and iliac) and total ASG scores were calculated using M2S software. RESULTS Of the 623 patients treated with EVAR, 79 (13%) had reinterventions of which 45 had preoperative M2S three-dimensional reconstructions available for ASG score calculation. The reintervention group (mean age, 74 ± 8; 80% male) had a mean ASG score of 18 ± 5 (range, 8-30) compared with a cohort of 45 EVAR patients (mean age, 74 ± 7; 80% male) who had a mean ASG score of 13 ± 4 (range, 6-21; P < .0001). The mean AAA diameter for all patients was 52 mm ± 14 and was not significantly different between the groups. After area under the receiver-operating curve analysis, an ASG score of 17 was highly predictive for reintervention (area = 0.8; sensitivity = 60%; specificity = 78%; positive predictive value = 73%; negative predictive value = 66%). An ASG score of 13 was highly predictive for freedom from reintervention (sensitivity = 93%; specificity = 47%; positive predictive value = 64%; negative predictive value = 88%). The lowest ASG score that yielded a 100% reintervention rate was 22. The majority of reinterventions fell into three categories: proximal extension cuff (n = 18; 40%), distal extension limb (n = 7; 16%), and type II endoleak embolization (n = 13; 29%). Those that received proximal extensions had significantly higher mean total ASG score (19 vs 15; P = .0005), mean neck score (3.28 vs 2.36; P = .047), and mean aorta score (7.39 vs 2.36; P = .004). Those that received distal extensions had a significantly higher mean iliac score (9.00 vs 6.86; P = .013), and those that required an embolization had a significantly higher mean aorta branch score (1.92 vs 1.19; P = .017). CONCLUSIONS Preoperative total ASG score strongly predicts reintervention after EVAR. Use of a cutoff ASG value predictive of prohibitive reintervention rates could help guide the decision between endovascular vs open AAA repair.

Volumetric analysis of the initial index computed tomography scan can predict the natural history of acute uncomplicated type B dissections

OBJECTIVE Our objective was to characterize the predictive impact of computed tomography (CT) scan volumetric analysis on the natural history of acute uncomplicated type B aortic dissections (ADs). METHODS We conducted a retrospective review of patients with acute type B ADs from 2009 to 2014. On an iNtuition workstation (TeraRecon, Foster City, Calif), volume measurements were obtained using the true lumen volume (TLV), false lumen volume (FLV), and total aortic volume from the left subclavian artery to the celiac artery. Growth rate was calculated as the change in maximal diameter between first and last available CT scans during the time interval. The primary outcome of the study was delayed aortic intervention. P < .05 was considered statistically significant. RESULTS During a 5-year period, 164 patients had CT scan evidence of acute type B ADs; 11 patients were excluded for lack of subsequent follow-up imaging; 36 patients who underwent urgent repair (<14 days from presentation) were also excluded. We evaluated a total of 117 patients: 85 patients who did not require intervention and 32 who underwent delayed (>14 days) thoracic endovascular aneurysm repair (29) or open repair (3). Mean age was 66 ± 12 years. Mean TLV/FLV ratio on initial CT scan was significantly higher in patients who did not eventually require an operation (1.55 vs 0.82; P = .02). The mean growth rate was higher in those eventually requiring operation (2.47 vs 0.42 mm/mo; P = .003). Patients were divided into three subgroups on the basis of their initial imaging TLV/FLV ratios (<0.8, 0.8-1.6, and >1.6). There was a significant difference in the growth rates between these three groups (4.6 vs 2.4 vs 0.8 mm/mo; P < .025). Area under the receiver operating characteristic curve analysis revealed that a TLV/FLV ratio <0.8 was highly predictive for requiring an intervention (area = 0.8; sensitivity, 69%; specificity, 84%: positive predictive value, 71%; negative predictive value, 81%), with an odds ratio of 12.2 (confidence interval, 5-26; P < .001). Conversely, a TLV/FLV ratio of >1.6 was highly predictive for freedom from delayed operation (sensitivity, 91%; specificity, 42%; positive predictive value, 61%; negative predictive value, 86%). After Kaplan-Meier analysis, 1-year and 2-year survival free of aortic interventions was 60% and 42% with a TLV/FLV ratio <0.8 and 92% and 82% with a ratio >1.6 (P = .001). CONCLUSIONS Initial CT scan volumetric analysis in patients presenting with uncomplicated acute type B ADs is a useful tool to predict growth and need for future intervention.

Patient Compliance Limits the Efforts of Quality Improvement Initiatives on Arteriovenous Fistula Maturation

OBJECTIVE Our institutional quality-improvement (QI) initiative instituted a well-defined office follow-up schedule after arteriovenous fistula (AVF) creation, including an office visit within 30 days, fistulogram within 40 days, if indicated, and a second office visit within 55 days. In addition, a patient liaison contacted patients and dialysis units to improve follow-up. The purpose of this study was to determine the effect of the QI initiative on patient compliance and overall time to AVF permission to cannulate. METHODS We performed a retrospective review of patients undergoing first-time radiocephalic, brachiocephalic, and basilic vein transposition creation before the QI initiative (pre-QI group: January to April 2012) and during the QI period (QI group: January to April 2013). Categoric data were compared using χ(2) analysis, and nominal data were compared using the Student t-test. RESULTS We reviewed 198 first-time AVF creations in patients (57% male) with a mean age of 61 years. Demographics and comorbidities between the pre-QI and QI groups were similar. Compliance with the first 30-day postoperative appointment increased significantly after the QI initiative, from 48% in the pre-QI group to 65% in the QI group (P = .015). Yet, the QI initiative did not maintain an effect on the subsequent follow-up checkpoints. No statistical difference was identified for compliance with fistulogram within 40 days of access creation (pre-QI, 12% vs QI, 25%; P = .093) or for compliance with the 55-day postoperative appointment (pre-QI, 33% vs QI, 23%; P = .457). Both checkpoints demonstrated a very high noncompliance rate. Accordingly, the mean time to permission to cannulate was 88 days for both the pre-QI and QI groups, with a failure to mature rate of 22% for the pre-QI group and 21% for the QI group (P = .816). CONCLUSIONS The QI initiative significantly increased the number of patients complying with the first 30-day follow-up appointment after AVF access creation. However, patient compliance with a timely fistulogram and the second follow-up appointment was poor and not influenced by the QI initiative, limiting the functional effect of the QI initiative on the time to AVF permission to cannulate.

The effect of demographic factors and lesion severity on iliac stent patency

OBJECTIVE The aim of our study was to perform a large multivariate analysis to identify demographic, anatomic, or procedural factors that affect iliac artery stent primary patency (PP). METHODS Patients receiving iliac stents from 2007 to 2013 were retrospectively reviewed. Univariate analysis assessed cohort characteristics and their effect on PP. Variables considered significant (P < .05) were brought forward in the multivariate analysis. RESULTS A total of 213 patients underwent primary iliac artery stenting, and 307 limbs were analyzed. The average age was 66 years (range, 38-93 years), 54% were male, and 55% were Caucasian. Indications for procedure were claudication in 68%, rest pain in 20%, and tissue loss in 12%. All TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) II classifications were included: 51% TASC II A, 25% TASC II B, 13% TASC II C, and 11% TASC II D. The treated anatomic locations were 27% isolated external iliac artery (EIA), 56% isolated common iliac artery, and 17% combined common iliac artery and EIA. Multivariate analysis found three factors were correlated with decreased PP: non-Caucasian race (hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.08-3.13; P = .025), younger age (HR, 1.04; 95% CI, 1.01-1.08; P = .006), and presence of EIA occlusion (HR, 2.02; 95% CI, 1.05-3.89; P = .036). Overall, Kaplan-Meier analysis at 1 and 3 years revealed a PP of 86% and 53%, assisted PP of 98% and 89%, and secondary patency of 99% of 98%. Kaplan-Meier analysis showed PP at 1 year for was 91% Caucasian patients vs 77% for non-Caucasian (P = .001). PP was 75% in patients aged <60 years, 86% in patients aged 60-70 years, and 96% in patients aged >70 years, with a significant difference between all groups (P < .001). PP was significantly different for those with and without EIA occlusion (P = .002), with 1-year PP of 71% and 88%, respectively. CONCLUSIONS In our experience with a large number of iliac interventions, younger age, non-Caucasian race, and EIA occlusion were strong predictors for loss of PP.

The impact of intravascular ultrasound on outcomes of endovascular repair of blunt traumatic aortic injury

Introduction Endovascular repair has become first-line therapy for traumatic aortic injury. Proper endograft sizing is critical to outcomes following traumatic aortic injury repair; however, the adequacy of standard imaging modalities for this purpose remains uncertain. We assessed the impact of intravascular ultrasound on outcomes of endovascular traumatic aortic injury repair. Methods A retrospective review was conducted for all traumatic aortic injury patients from 2005 to 2015. Primary endpoints were 30-day aortic-related complications (aortic-related mortality, stroke, and spinal cord ischemia) and late device-related complications (collapse, migration, endoleak, and reintervention) over the duration of follow-up. Aortic measurements were calculated from three-dimensional-reconstructed computerized tomography studies and intravascular ultrasound images. Aortic remodeling was quantified by volume change between initial and first follow-up computerized tomography scans. Results Twenty-five patients were included (mean age 41, 72% male). Intravascular ultrasound was used in 14 patients. No differences in demographics or injury characteristics were observed between intravascular ultrasound and non-intravascular ultrasound patients. Proximal neck diameter was 1.2 mm greater on intraoperative intravascular ultrasound than initial computerized tomography imaging (P = .048). Endograft oversizing in relation to initial computerized tomography was 25% in intravascular ultrasound patients versus 9% in non-intravascular ultrasound patients (P = .001). No significant differences in aortic-related complications were noted. Device-related complications occurred more frequently in the non-intravascular ultrasound group at a mean follow-up of 252 days (36.4% vs. 0%, P = .026). Aortic remodeling rate was 4.41 cm3/day in the intravascular ultrasound group versus 2.34 cm3/day in the non-intravascular ultrasound group (P = .256). Conclusions Intravascular ultrasound significantly impacts endograft sizing and was associated with decreased device-related complications following endovascular traumatic aortic injury repair.

INTRAVASCULAR ULTRASOUND ARTERIAL MEASUREMENTS PREDICT VASCULAR ACCESS SITE COMPLICATIONS IN TRANSFEMORAL AORTIC VALVE REPLACEMENT

Vascular complications of Transcatheter Aortic Valve Replacement (TAVR) have been recognized since the procedure’s inception. Studies have shown that CTA measurements of the femoral artery predict vascular complications. This study was designed to evaluate intravascular ultrasound (IVUS) arterial