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  • Ruptured Pseudoaneurysm of the Dorsalis Pedis Artery Following Ankle Arthroscopy: A Case Report. JBJS case connector Wiske, C. P., Itoga, N. K., Ullery, B. W., Hunt, K. J., Chandra, V. ; 6 (4): e102

    Abstract

    We describe the case of a pseudoaneurysm of the dorsalis pedis artery that developed following a repeat ankle arthroscopy for persistent osseous impingement. The patient underwent attempted fluid aspiration for a presumed effusion, and ultimately experienced rupture of the pseudoaneurysm with substantial blood loss, which required emergency vascular repair.Anterior tibial artery and dorsalis pedis artery pseudoaneurysms are relatively rare, but they are well-documented complications of ankle arthroscopy; however, their clinical importance is poorly understood. To our knowledge, this is the first reported case of a ruptured pseudoaneurysm of the dorsalis pedis artery following ankle surgery, and it highlights the need for timely diagnosis.

    View details for PubMedID 29252755

    View details for PubMedCentralID PMC5901686

  • Impact of office-based laboratories on physician practice patterns and outcomes after percutaneous vascular interventions for peripheral artery disease. Journal of vascular surgery Itoga, N. K., Baker, L. C., Mell, M. W. 2019

    Abstract

    BACKGROUND: Percutaneous vascular interventions (PVIs) for peripheral artery disease have shifted from hospital-based facilities to office-based laboratories (OBLs). The transition to OBLs is due to a variety of factors such as technology advancement, increased efficiency, and financial incentives. We evaluated the impact of physicians switching to OBLs use from hospital-based facilities on procedure volume, procedure type, and patient outcomes.METHODS: We identified patients with PVI for lower extremity peripheral artery disease from 2006 to 2013 in a 20% Medicare sample and identified physicians who transitioned from predominantly hospital-based facilities to OBLs (switch physicians) and compared them with those who did not use OBLs (control physicians). The main outcomes investigated were average number of PVIs at 30days and 1year and atherectomy usage. Patient outcomes included above-ankle amputation, major adverse limb events, and death. We used a difference-in-difference model to control for time effects in a multivariate regression model, reported as an odds ratio (OR) and 95% confidence interval (CI).RESULTS: The cohort comprised 292 switch physicians, who treated 7134 patients (3888 before OBL use and 3246 after transitioning to OBLs), and 3715 control physicians treating 54,213 patients (36,327 in the preperiod and 17,886 in the postperiod). Switch and control physicians both treated more patients with lower extremity wounds during the study period; however, this increase was greater for control physician (0.7% vs 5.5%, P< .001). On average, patients treated by switch physicians had 0.05 (95% CI, 0.03-0.07; P< .001) underwent more PVIs within 30days and 0.12 more PVIs (95% CI, 0.08-0.16; P< .001) within 1year of the initial revascularization procedure after the physician transitioned to an OBL. Similarly, patients treated by switch physicians underwent 0.02 (95% CI, 0.01-0.03; P= .002) more atherectomy procedures at 30days and 0.03 (95% CI, 0.01-0.05; P= .008) more atherectomy procedures at 1year. Transitioning to OBLs was also associated with a decreased risk in above-ankle amputation at 30days (OR, 0.58; 95% CI, 0.38-0.97; P= .009) and 1year (OR, 0.75; 95% CI, 0.60-0.95; P= .01). However, no statistical difference was observed for major adverse limb events and mortality rates at 30days and 1year because patients treated by switch and control physicians experienced similar decreases.CONCLUSIONS: Transitioning to OBLs was associated higher 30-day and 1-year PVI rates and atherectomy rates. Although transitioning to OBLs was associated with lower rates of above-ankle amputations, switch physicians treated a lower number of patients with lower extremity wounds.

    View details for DOI 10.1016/j.jvs.2019.01.060

    View details for PubMedID 31204219

  • Factors Affecting Intervention Rates and Time to Intervention for Lower Extremity Venous Disease in the Private Insurance Market Itoga, N. K., Rothenberg, K. A., George, E. L., Deslarzes-Dubuis, C., Rapanos, T., Harris, E. J. MOSBY-ELSEVIER. 2019: E255–E256
  • Oakes Salvage Procedure Is a Better, More Durable Option Compared With Forearm Loop Expanded Polytetrafluoroethylene Graft to Preserve Forearm Dialysis Access in Patients With Failing Brescia-Cimino Fistula Lavingia, K., Dua, A., Colvard, B., Itoga, N. K., Deslarzes-Dubuis, C., Garcia-Toca, M., Sorial, E. MOSBY-ELSEVIER. 2019: E242–E243
  • Impact of Office-Based Laboratories on Medicare Payments for Percutaneous Interventions for Peripheral Artery Disease Itoga, N. K., Baker, L. C., Mell, M. W. MOSBY-ELSEVIER. 2019: E196–E197
  • Forearm loop arteriovenous grafts preserve and may create new upper arm access sites. The journal of vascular access Itoga, N. K., Virgin-Downy, W., Mell, M. W. 2019: 1129729819835137

    Abstract

    INTRODUCTION: This study evaluated the mid-term patency of forearm loop arteriovenous grafts and the dilation of previously inadequate upper arm basilic and cephalic veins after failed forearm loop arteriovenous graft.METHODS: All access procedures from September 2009 to December 2015 were reviewed. Vein mapping measurements were used to determine whether there was "adequate" upper arm cephalic and/or basilic vein, defined as ⩾3mm by duplex ultrasound, at the time of forearm loop arteriovenous graft creation. Outcomes of forearm loop arteriovenous graft were compared with upper arm arteriovenous fistula, and primary and cumulative patencies were evaluated.RESULTS: Thirty-eight forearm loop arteriovenous grafts and 278 upper arm arteriovenous fistulas were created. In the forearm loop arteriovenous graft cohort, nine were inserted with adequate upper arm vein, group A, and 29 were inserted with inadequate upper arm vein, group B. Cumulative patency was lower for forearm loop arteriovenous graft compared with upper arm arteriovenous fistula at 6months, 1year, and 2years (67% vs 91%, 61% vs 85%, and 49% vs 80%, respectively, P<.01). Comparison of group A forearm loop arteriovenous graft and upper arm arteriovenous fistula did not show a statistical difference in cumulative patency at 6months, 1year, and 2years (P=.80, .62, and .70, respectively). Of group B with failed forearm loop arteriovenous graft, 36% became candidates for upper arm arteriovenous fistula with dilation of ipsilateral upper arm cephalic or basilic vein to ⩾3mm.CONCLUSION: In this study, forearm loop arteriovenous graft with adequate upper arm vein did not show a statistical difference in mid-term patencies compared with upper arm arteriovenous fistula. For those forearm loop arteriovenous grafts with inadequate upper arm vein, approximately one-third of patients became candidates for upper arm arteriovenous fistula demonstrating the benefits forearm loop arteriovenous graft.

    View details for PubMedID 31006339

  • Response by Itoga et al to Letter Regarding Article, "Association of Blood Pressure Measurements With Peripheral Arterial Disease Events" CIRCULATION Itoga, N. K., Tawfik, D. S., Leeper, N. J., Chang, T. I. 2019; 139 (15): 1855–56
  • Association of opioid use and peripheral artery disease. Journal of vascular surgery Itoga, N. K., Sceats, L. A., Stern, J. R., Mell, M. W. 2019

    Abstract

    BACKGROUND: Prescription opioids account for 40% of all U.S. opioid overdose deaths, and national efforts have intensified to reduce opioid prescriptions. Little is known about the relationship between peripheral artery disease (PAD) and high-risk opioid use. The objectives of this study were to evaluate this relationship and to assess the impact of PAD treatment on opiate use.METHODS: In this retrospective cohort study, the Truven Health MarketScan database (Truven Health Analytics, Ann Arbor, Mich), a deidentified national private insurance claims database, was queried to identify patients with PAD (two or more International Classification of Diseases, Ninth Revision diagnosis codes of PAD ≥2months apart, with at least 2years of continuous enrollment) from 2007 to 2015. Critical limb ischemia (CLI) was defined as the presence of rest pain, ulcers, or gangrene. The primary outcome was high opioid use, defined as two or more opioid prescriptions within a 1-year period. Multivariable analysis was used to determine risk factors for high opioid use.RESULTS: A total of 178,880 patients met the inclusion criteria, 35% of whom had CLI. Mean± standard deviation follow-up time was 5.3± 2.1years. An average of 24.7% of patients met the high opioid use criteria in any given calendar year, with a small but significant decline in high opioid use after 2010 (P< .01). During years of high opioid use, 5.9± 5.5 yearly prescriptions were filled. A new diagnosis of PAD increased high opioid use (21.7% before diagnosis vs 27.3% after diagnosis; P<.001). A diagnosis of CLI was also associated with increased high opioid use (25.4% before diagnosis vs 34.5% after diagnosis; P< .001). Multivariable analysis identified back pain (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.84-1.93; P< .001) and illicit drug use (OR, 1.87; 95% CI, 1.72-2.03; P< .001) as the highest predictors of high opioid use. A diagnosis of CLI was also associated with higher risk (OR, 1.61; 95% CI, 1.57-1.64; P< .001). A total of 43,443 PAD patients (24.3%) underwent 80,816 PAD-related procedures. After exclusion of periprocedural opioid prescriptions (4.9% of all opioid prescriptions), the yearly percentage of high opioid users increased from 25.8% before treatment to 29.6% after treatment (P< .001).CONCLUSIONS: Patients with PAD are at increased risk for high opioid use, with nearly one-quarter meeting described criteria. CLI and treatment for PAD additionally increase high opioid use. In addition to heightened awareness and active opioid management, our findings warrant further investigation into underlying causes and deterrents of high-risk opioid use.

    View details for PubMedID 30922747

  • Metformin prescription status and abdominal aortic aneurysm disease progression in the US veteran population JOURNAL OF VASCULAR SURGERY Itoga, N. K., Rothenberg, K. A., Suarez, P., Ho, T., Mell, M. W., Xu, B., Curtin, C. M., Dalman, R. L. 2019; 69 (3): 710-+
  • Incidence and Risk Factors for Deep Vein Thrombosis after Radiofrequency and Laser Ablation of the Lower Extremity Veins. Annals of vascular surgery Itoga, N. K., Rothenberg, K. A., Deslarzes-Dubuis, C., George, E. L., Chandra, V., Harris, E. J. 2019

    Abstract

    The rates of thromboembolic complications such as deep venous thrombosis (DVT) after venous ablation procedures for symptomatic superficial venous insufficiency are controversial. We sought to describe the risk factors for, and incidence of DVT after radiofrequency ablation (RFA) and laser ablation (LA).We queried the Truven Health Marketscan Database from 2007-16 for patients who underwent RFA or LA and had a follow-up duplex ultrasound within 30 days of the ablation procedure. The primary outcome was DVT at 7- and 30-days identified by ICD-9 and ICD-10 codes. Multivariable regression was used to evaluate the patient and procedural variables associated with a DVT at 30-days, expressed as odds ratios with a 95% confidence interval (OR 95%CI). Patients and procedures with a previous DVT diagnosis were excluded.A total of 256,999 patients underwent 433,286 ablation procedures: 192,195 (44.4%) RFA and 241,091 LA. Of these, 8,203 (1.9%) had a newly diagnosed DVT within 7-days and 13,347 (3.1%) within 30-days of the procedure. The incidence of DVT decreased over the study period. LA (2.8%) demonstrated a lower incidence of DVT at 30-days compared to RFA (3.4%), p<0.001. On multivariable regression, LA (OR 0.82, 95%CI 0.80-0.85) was again associated with a decreased risk for 30-day DVT, as was female gender (OR 0.74, 95%CI 0.71-0.77) and sclerotherapy performed on the same day (OR 0.91, 95%CI 0.85-0.98). A diagnosis of peripheral artery disease (OR 1.23, 95%CI 1.16-1.31) and concomitant stab phlebectomy (OR 1.43, 95%CI 1.37-1.49) was associated with an increased risk of DVT within 30-days.The incidence of newly diagnosed DVT within 30-days of an ablation procedure was 3.2%. The risk for DVT decreased in recent years and LA was associated with a 18% decreased risk compared to RFA.

    View details for DOI 10.1016/j.avsg.2019.04.008

    View details for PubMedID 31201974

  • Arteriovenous Fistula and Graft Construction in Patients with Implantable Cardiac Devices: Does Side Matter? Annals of vascular surgery Sgroi, M. D., McFarland, G., Itoga, N. K., Sorial, E., Garcia-Toca, M. 2018

    Abstract

    BACKGROUND: Limited reports have documented the effect cardiac implantable electronic devices (CIEDs) have on arteriovenous (AV) access patency. Current recommendations suggest placing the access on the contralateral side of the CIEDs, as there is concern for increased central venous stenosis and access failure. The goal of this study is to review our single-center AV access patency rates for dialysis patients with an ipsilateral or contralateral side CIED.METHODS: A retrospective review was performed from 2008 to 2016 at a single institution identifying all patients who have received a CIED and the diagnosis of end-stage renal disease (ESRD). Medical records were queried to identify each patient's dialysis access and whether it was ipsilateral or contralateral to the CIED. Primary outcomes of study were primary and secondary patency rates.RESULTS: A total of 44 patients were identified to have ESRD and CIED. Of these patients, 28 patients with fistulas or grafts (13 ipsilateral and 15 contralateral) had follow-up with regards to their AV access. There were 3 primary failures in both groups. For patients who had the CIED placed after already starting the dialysis, patency was based on when the cardiac device was implanted. Primary patency for ipsilateral and contralateral access was 20.2 and 22.2months, respectively. With secondary interventions, ipsilateral and contralateral mean patency was 39 and 48.8months, respectively. Six-month and 1-year primary patency for arteriovenous fistula or arteriovenous graft on patients with ipsilateral access was 69.2% and 53.8%, respectively. Ipsilateral 1-year cumulative patency was 39months.CONCLUSIONS: CIED may lead to stenosis or occlusion to one's AV access; however, primary assisted and secondary patency rates are still acceptable at 6months and 1year compared to Kidney Disease Outcomes Quality Initiative guidelines. Despite a CIED, a surgeon's algorithm should not lead to the abandonment of an ipsilateral access if the central venous system is patent.

    View details for PubMedID 30339901

  • Metformin prescription status and abdominal aortic aneurysm disease progression in the U.S. veteran population. Journal of vascular surgery Itoga, N. K., Rothenberg, K. A., Suarez, P., Ho, T., Mell, M. W., Xu, B., Curtin, C. M., Dalman, R. L. 2018

    Abstract

    BACKGROUND: Identification of a safe and effective medical therapy for abdominal aortic aneurysm (AAA) disease remains a significant unmet medical need. Recent small cohort studies indicate that metformin, the world's most commonly prescribed oral hypoglycemic agent, may limit AAA enlargement. We sought to validate these preliminary observations in a larger cohort.METHODS: All patients with asymptomatic AAA disease managed in the Veterans Affairs Health Care System between 2003 and 2013 were identified by International Classification of Diseases, Ninth Revision codes. Those with a concomitant diagnosis of diabetes mellitus who also received two or more abdominal imaging studies (computed tomography, magnetic resonance imaging, or ultrasound) documenting the presence and size of an AAA, separated by at least 1year, were included for review. Maximal AAA diameters were determined from radiologic reports. Further data acquisition was censored after surgical AAA repair, when performed. Comorbidities, active smoking status, and outpatient medication records (within 6months of AAA diagnosis) were also queried. Yearly AAA enlargement rates, as a function of metformin treatment status, were compared using two statistical models expressed in millimeters per year: a multivariate linear regression (model 1) and a multivariate mixed-effects model with random intercept and random slope (model 2).RESULTS: A total of 13,834 patients with 58,833 radiographic records were included in the analysis, with radiology imaging follow-up of 4.2± 2.6years (mean± standard deviation). The average age of the patients at AAA diagnosis was 69.8± 7.8years, and 39.7% had a metformin prescription within±6months of AAA. The mean growth rate for AAAs in the entire cohort was 1.4± 2.0mm/y by model 1 analysis and 1.3± 1.6mm/y by model 2 analysis. The unadjusted mean rate of AAA growth was 1.2± 1.9mm/y for patients prescribed metformin compared with 1.5± 2.2mm/y for those without (P< .001), a 20% decrease. This effect remained significant when adjusted for variables relevant on AAA progression: metformin prescription was associated with a reduction in yearly AAA growth rate of-0.23mm (95% confidence interval,-0.35 to-0.16; P< .001) by model 1 analysis and 0.20mm/y (95% confidence interval,-0.26 to-0.14; P< .001) by model 2 analysis. A subset analysis of 7462 patients with baseline AAA size of 35 to 49mm showed a similar inhibitory effect (1.4± 2.0mm/y to 1.7± 2.2mm/y; P< .001). Patients' factors associated with an increased yearly AAA growth rate were baseline AAA size, metastatic solid tumors, active smoking, chronic obstructive pulmonary disease, and chronic renal disease. Factors associated with decreased yearly AAA growth rates included prescriptions for angiotensin II type 1 receptor blockers or sulfonylureas and the presence of diabetes-related complications.CONCLUSIONS: In a nationwide analysis of diabetic Veterans Affairs patients, prescription for metformin was associated with decreased AAA enlargement. These findings provide further support for the conduct of prospective clinical trials to test the ability of metformin to limit progression of early AAA disease.

    View details for PubMedID 30197158

  • Comparison of Bovine Carotid Xenograft Versus Expanded Polytetrafluoroethylene Grafts for Forearm Loop Hemodialysis Access Colvard, B., Lavignia, K., Ho, V. T., Itoga, N., Dua, A., Harris, E., Me, M., Sorial, E., Garcia-Toca, M. MOSBY-ELSEVIER. 2018: E35
  • Episode-based cost reduction for endovascular aneurysm repair. Journal of vascular surgery Itoga, N. K., Tang, N., Patterson, D., Ohkuma, R., Lew, R., Mell, M. W., Dalman, R. L. 2018

    Abstract

    OBJECTIVE: Effective strategies to reduce costs associated with endovascular aneurysm repair (EVAR) remain elusive for many medical centers. In this study, targeted interventions to reduce inpatient EVAR costs were identified and implemented.METHODS: From June 2015 to February 2016, we analyzed the EVAR practice at a high-volume academic medical center to identify, to rank, and ultimately to reduce procedure-related costs. In this analysis, per-patient direct costs to the hospital were compared before (September 2013-May 2015) and after (March 2016-January 2017) interventions were implemented. Improvement efforts concentrated on three categories that accounted for a majority of costs: implants, rooming costs, and computed tomography scans performed during the index hospitalization.RESULTS: Costs were compared between 141 EVAR procedures before implementation (PRE period) and 47 EVAR procedures after implementation (POST period). Based on data obtained through the Society for Vascular Surgery EVAR Cost Demonstration Project, it was determined that implantable device costs were higher than those at peer institutions. New purchasing strategies were implemented, resulting in a 30.8% decrease in per-case device costs between the PRE and POST periods. Care pathways were modified to reduce use of and costs for computed tomography scans obtained during the index hospitalization. Compared with baseline, per-case imaging costs decreased by 92.9% (P< .001), including a 99.0% (P= .001) reduction in postprocessing costs. Care pathways were also implemented to reduce preprocedural rooming for patients traveling long distances the day before surgery, resulting in a 50% decrease in utilization rate (35.4% PRE to 17.0% POST; P= .021), without having a significant impact on median postprocedural length of stay (PRE, 2days [interquartile range, 1-11days]; POST, 2days [1-7days]; P= .185). Medication costs also decreased by 38.2% (P< .001) as a hospital-wide effort.CONCLUSIONS: Excessive costs associated with EVAR threaten the sustainability of these procedures in health care organizations. Targeted cost reduction efforts can effectively reduce expenses without compromising quality or limiting patients' access.

    View details for PubMedID 30185384

  • Association of Blood Pressure Measurements with Peripheral Arterial Disease Events: A Reanalysis of the ALLHAT Data. Circulation Itoga, N. K., Tawfik, D. S., Lee, C. K., Maruyama, S., Leeper, N. J., Chang, T. I. 2018

    Abstract

    Background -Current guidelines recommend treating hypertension in patients with peripheral arterial disease (PAD) to reduce the risk of cardiac events and stroke, but the effect of reducing blood pressure on lower extremity PAD events is largely unknown. We investigated the association of blood pressure with lower extremity PAD events using data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Methods -ALLHAT investigated the effect of different antihypertensive medication classes (chlorthalidone, amlodipine, lisinopril, or doxazosin) on cardiovascular events. Using these data, the primary outcome in our analysis was time to first lower extremity PAD event, defined as PAD-related hospitalization, procedures, medical treatment, or PAD-related death. Given the availability of longitudinal standardized blood pressure measurements, we analyzed systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) as time-varying categorical variables (reference categories 120-129 mm Hg for SBP, 70-79 mm Hg for DBP, and 45-54 mm Hg for PP) in separate models. We used extended Cox regression with death as a competing risk to calculate the association of each BP component with PAD events, and report the results as sub-distribution hazard ratios (HR) and 95% confidence intervals (CI). Results -The present analysis included 33,357 patients with an average age of 67.4 years, 53.1% men, 59.7% white race, and 36.2% with diabetes mellitus. The median baseline blood pressure was 146/84 mm Hg. Participants were followed for a median of 4.3 (IQR 3.6-5.3) years, during which time 1,489 (4.5%) had a lower extremity PAD event, and 4,148 (12.4%) died. In models adjusted for demographic and clinical characteristics, SBP <120 mm Hg was associated with a 26% (CI 5-52%, P=0.015) higher hazard and SBP≥160 mm Hg was associated with a 21% (CI 0-48%, P=0.050) higher hazard for a PAD event, compared with SBP 120-129 mm Hg. In contrast, lower, but not higher, DBP was associated with higher hazard of PAD events: for DBP <60 mm Hg HR = 1.72 (CI 1.38 - 2.16). PP had a U-shaped association with PAD events. Conclusions -In this re-analysis of data from ALLHAT, we found a higher rate of lower extremity PAD events with higher and lower SBP and PP, and with lower DBP. Given the recent revised blood pressure guidelines advocating lower SBP targets for overall cardiovascular risk reduction, further refinement of optimal blood pressure targets specific to PAD is needed. Clinical Trial Registration -URL: www.clinicaltrials.gov Unique identifier: NCT00000542.

    View details for PubMedID 29930023

  • Metformin Prescription Status and Abdominal Aortic Aneurysm Disease Progression in the US Veteran Patient Population Itoga, N. K., Rothenberg, K. A., Suarez, P., Vy Thuy Ho, Mell, M. W., Xu, B., Curtin, C. M., Dalman, R. L. MOSBY-ELSEVIER. 2018: E52
  • Association of Opioid Abuse and Peripheral Arterial Disease Itoga, N. K., Sceats, L. A., Stern, J. R., Mell, M. W. MOSBY-ELSEVIER. 2018: E87
  • Stabilization of the Abdominal Aorta During the Cardiac Cycle with the Sac-Anchoring Nellix Device. Annals of vascular surgery Itoga, N. K., Suh, G., Cheng, C. P. 2018

    Abstract

    The Nellix device utilizes polymer filled endobags to stabilize the abdominal aortic aneurysm (AAA) sac described as endovascular aneurysm sealing (EVAS). We analyzed cardiac gated CTA scans of repaired AAA with EVAS in four patients to evaluate geometry and cardiac pulsatility-induced deformation. Graft translation and aortic curvature changes were found to be minimal during the cardiac cycle. The mean±SD changes in renal-aorta angles (1.0±0.9°) were less than the changes in the SMA-aorta angle (4.0±2.1°) (P<0.01), during the cardiac cycle, demonstrating greater stabilization of the visceral branches closer to the device. These findings confirm stabilization of the abdominal aorta during the cardiac cycle using EVAS.

    View details for PubMedID 29775657

  • Cost-effectiveness analysis of asymptomatic peripheral artery disease screening with the ABI test VASCULAR MEDICINE Itoga, N. K., Minami, H. R., Chelvakumar, M., Pearson, K., Mell, M. M., Bendavid, E., Owens, D. K. 2018; 23 (2): 97–106

    Abstract

    Screening for asymptomatic peripheral artery disease (aPAD) with the ankle-brachial index (ABI) test is hypothesized to reduce disease progression and cardiovascular (CV) events by identifying individuals who may benefit from early initiation of medical therapy. Using a Markov model, we evaluated the cost effectiveness of initiating medical therapy (e.g. statin and ACE-inhibitor) after a positive ankle-brachial index (ABI) screen in 65-year-old patients. We modeled progression to symptomatic PAD (sPAD) and CV events with and without ABI screening, evaluating differences in costs and quality-adjusted life years (QALYs). The cost of the ABI test, physician visit, new medication, CV events, and interventions for sPAD were incorporated in the model. We performed sensitivity analysis on model variables with uncertainty. Our model found an incremental cost of US $338 and an incremental QALY of 0.00380 with one-time ABI screening, resulting in an incremental cost-effectiveness ratio (ICER) of $88,758/QALY over a 35-year period. The variables with the largest effects in the ICER were aPAD disease prevalence, cost of monthly medication after a positive screen and 2-year medication adherence rates. Screening high-risk populations, such as tobacco users, where the prevalence of PAD may be 2.5 times higher, decreases the ICER to $24,092/QALY. Our analysis indicates the cost effectiveness of one-time screening for aPAD depends on prevalence, medication costs, and adherence to therapies for CV disease risk reduction. Screening in higher-risk populations under favorable assumptions about medication adherence results in the most favorable cost effectiveness, but limitations in the primary data preclude definitive assessment of cost effectiveness.

    View details for PubMedID 29345540

    View details for PubMedCentralID PMC5893367

  • Acute Type B Dissection Causing Collapse of EVAR Endograft and Iliac Limb Occlusion Itoga, N. K., Wu, T., Dake, M. D., Dalman, R. L., Lee, J. T. ELSEVIER SCIENCE INC. 2018: 206.e1–206.e4

    Abstract

    We describe a rare case of acute type B dissection (ATBDs) causing collapse of a previously placed infrarenal stent graft, resulting in acute limb ischemia due to left iliac limb thrombosis in a 59-year-old male. The patient presented with acute back and abdominal discomfort radiating to his back, bilateral buttock stabbing discomfort and left > right thigh and calf rest pain. CT angiography showed a spiral type B dissection with collapse of the proximal portion of the endovascular repair of aortic aneurysm (EVAR) device and left limb occlusion. Urgent treatment with thoracic endovascular aortic repair distal to the left subclavian covered the entry tear and redirected the majority of the flow to the true lumen leading to near immediate expansion of the proximal portion of the EVAR device. After surgical femoral control, balloon embolectomy of the occluded iliac limb was performed and the limb relined. His lower extremity ischemic symptoms resolved, and his abdominal and back pain dissipated. At latest 6-month follow-up, CT angiography shows an intact thoracic endovascular aortic repair stent graft and a widely patent EVAR stent graft, and the patient has no further abdominal, back, or leg symptoms. ATBD causing proximal abdominal EVAR collapse is an extremely rare presentation of false lumen pressurization and can be treated similarly to complicated type B dissection with the goal of restoring true lumen patency.

    View details for PubMedID 28739456

    View details for PubMedCentralID PMC5842241

  • Mycotic Renal Artery Aneurysm Presenting as Critical Limb Ischemia in Culture-Negative Endocarditis CASE REPORTS IN SURGERY Vy Thuy Ho, Itoga, N. K., Wu, T., Sorial, E., Garcia-Toca, M. 2018: 7080813

    Abstract

    Mycotic renal artery aneurysms are rare and can be difficult to diagnose. Classic symptoms such as hematuria, hypertension, or abdominal pain can be vague or nonexistent. We report a case of a 53-year-old woman with a history of intravenous drug abuse presenting with critical limb ischemia, in which CT angiography identified a mycotic renal aneurysm. This aneurysm tripled in size from 0.46 cm to 1.65 cm in a 3-week interval. Echocardiography demonstrated aortic valve vegetations leading to a diagnosis of culture-negative endocarditis. The patient underwent primary resection and repair of the aneurysm, aortic valve replacement, and left below-knee amputation after bilateral common iliac and left superficial femoral artery stenting. At 1-year follow-up, her serum creatinine is stable and repaired artery remains patent.

    View details for PubMedID 29854544

    View details for PubMedCentralID PMC5964565

  • Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery. Journal of vascular surgery Itoga, N. K., Kim, T., Sailer, A. M., Fleischmann, D., Mell, M. W. 2017

    Abstract

    Preprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region.Medical records and available imaging studies were reviewed for patients undergoing endovascular intervention for PAD between January 2013 and December 2015 at a single academic institution. Radiologists reviewed preoperative CTA scans of patients with occlusions in the SFA-pop region. Radiographic criteria previously used to evaluate chronic occlusions in the coronary arteries were used. Technical success, defined as restoration of inline flow through the SFA-pop region with <30% stenosis at the end of the procedure, and intraoperative details were evaluated.From 2013 to 2015, there were 407 patients who underwent 540 endovascular procedures for PAD. Preprocedural CTA scans were performed in 217 patients (53.3%), and 84 occlusions in the SFA-pop region were diagnosed. Ten occlusions were excluded as no endovascular attempt to cross the lesion was made because of extensive disease or concomitant iliac intervention. Of the remaining 74 occlusions in the SFA-pop region, 59 were successfully treated (80%) and 15 were unsuccessfully crossed (20%). The indications for revascularization were claudication in 57% of patients and critical limb ischemia in the remaining patients. TransAtlantic Inter-Society Consensus A, B, and C occlusions were treated with 87% success, whereas D occlusions were treated with 68% success (P = .047). There were nine occlusions with 100% vessel calcification that was associated with technical failure (P = .014). Longer lengths of occlusion were also associated with technical failure (P = .042). Multiple occlusions (P = .55), negative remodeling (P = .69), vessel runoff (P = .56), and percentage of vessel calcification (P = .059) were not associated with failure. On multivariable analysis, 100% calcification remained the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P = .008).Analysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endovascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD.

    View details for DOI 10.1016/j.jvs.2017.02.031

    View details for PubMedID 28502550

  • Natural history of gutter-related type Ia endoleaks after snorkel/chimney endovascular aneurysm repair. Journal of vascular surgery Ullery, B. W., Tran, K., Itoga, N. K., Dalman, R. L., Lee, J. T. 2017

    Abstract

    Alternative endovascular strategies using parallel or snorkel/chimney (chimney endovascular aneurysm repair [ch-EVAR]) techniques have been developed to address the lack of widespread availability and manufacturing limitations with branched/fenestrated aortic devices for the treatment of complex abdominal aortic aneurysms. Despite high technical success and midterm patency of snorkel stent configurations, concerns remain regarding the perceived increased incidence of early gutter-related type Ia endoleaks. We aimed to evaluate the incidence and natural history of gutter-related type Ia endoleaks following ch-EVAR.Review of medical records and available imaging studies, including completion angiography and serial computed tomographic angiography, was performed for all patients undergoing ch-EVAR at our institution between September 2009 and January 2015. Only procedures involving ≥1 renal artery with or without visceral snorkel stents were included. Primary outcomes of the study were presence and persistence or resolution of early gutter-related type Ia endoleak. Secondary outcomes included aneurysm sac shrinkage and need for secondary intervention related to the presence of type Ia gutter endoleak.Sixty patients (mean age, 75.8 ± 7.6 years; male, 70.0%) underwent ch-EVAR with a total of 111 snorkel stents (97 renal [33 bilateral renal], 12 superior mesenteric artery, 2 celiac). A mean of 1.9 ± 0.6 snorkel stents were placed per patient. Early gutter-related type Ia endoleaks were noted on 30.0% (n = 18) of initial postoperative imaging studies. Follow-up imaging revealed spontaneous resolution of these gutter endoleaks in 44.3%, 65.2%, and 88.4% of patients at 6, 12, and 18 months postprocedure, respectively. Long-term anticoagulation, degree of oversizing, stent type and diameter, and other clinical/anatomic variables were not significantly associated with presence of gutter endoleaks. Two patients (3.3%) required secondary intervention related to persistent gutter endoleak. At a mean radiologic follow-up of 20.9 months, no difference in mean aneurysm sac size change was observed between those with or without early type Ia gutter endoleak (-6.1 ± 10.0 mm vs -4.9 ± 11.5 mm; P = .23).Gutter-related type Ia endoleaks represent a relatively frequent early occurrence after ch-EVAR, but appears to resolve spontaneously in the majority of cases during early to midterm follow-up. Given that few ch-EVAR patients require reintervention related to gutter endoleaks and the presence of such endoleak did not correlate to increased risk for aneurysm sac growth, its natural history may be more benign than originally expected.

    View details for DOI 10.1016/j.jvs.2016.10.085

    View details for PubMedID 28189356

  • Outcomes of Endovascular Repair of Aortoiliac Aneurysms and Analyses of Anatomic Suitability for Internal Iliac Artery Preserving Devices in Japanese Patients. Circulation journal Itoga, N. K., Fujimura, N., Hayashi, K., Obara, H., Shimizu, H., Lee, J. T. 2017

    Abstract

    Understanding that the common iliac arteries (CIA) are shorter in Asian patients, we investigated whether this anatomic difference affects the clinical outcomes of internal iliac artery (IIA) exclusion during endovascular aneurysm repair (EVAR) of aortoiliac aneurysm and thus limits the use of IIA-preserving devices in Japanese patients.Methods and Results:From 2008 to 2014, 69 Japanese patients underwent EVAR of aortoiliac aneurysms with 53 unilateral and 16 bilateral IIA exclusions. One patient had persistent buttock claudication during follow-up; however, colonic or spinal cord ischemia was not observed. Anatomic suitability was investigated for the iliac branch device (IBD) by Cook Medical and the iliac branch endoprosthesis (IBE) by WL Gore: 87 aortoiliac segments were analyzed, of which 17% met the criteria for the IBD, 25% met the criteria for the IBE and 40% met the criteria for either. Main exclusions for the IBD were IIA diameter >9 mm or <6 mm (47%) and CIA length <50 mm (39%). Main exclusions for the IBE were proximal CIA diameter <17 mm (44%) and aortoiliac length <165 mm (24%).EVAR with IIA exclusions in Japanese patients showed low incidence of persistent buttock claudication and no major pelvic complications. Aorto-iliac morphology demonstrated smaller proximal CIA diameters and shorter CIA lengths, limiting the use of IIA-preserving devices.

    View details for DOI 10.1253/circj.CJ-16-1109

    View details for PubMedID 28154297

  • Polar orientation of renal grafts within the proximal seal zone affects risk of early type Ia endoleaks after chimney endovascular aneurysm repair. Journal of vascular surgery Tran, K., Ullery, B. W., Itoga, N., Lee, J. T. 2017

    Abstract

    The objective of this study was to describe the polar orientation of renal chimney grafts within the proximal seal zone and to determine whether graft orientation is associated with early type Ia endoleak or renal graft compression after chimney endovascular aneurysm repair (ch-EVAR).Patients who underwent ch-EVAR with at least one renal chimney graft from 2009 to 2015 were included in this analysis. Centerline three-dimensional reconstructions were used to analyze postoperative computed tomography scans. The 12-o'clock polar position was set at the takeoff of the superior mesenteric artery. Relative polar positions of chimney grafts were recorded at the level of the renal artery ostium, at the mid-seal zone, and at the proximal edge of the graft fabric. Early type Ia endoleaks were defined as evidence of a perigraft flow channel within the proximal seal zone.There were 62 consecutive patients who underwent ch-EVAR (35 double renal, 27 single renal) for juxtarenal abdominal aortic aneurysms with a mean follow-up of 31.2 months; 18 (29%) early type Ia "gutter" endoleaks were identified. During follow-up, the majority of these (n = 13; 72%) resolved without intervention, whereas two patients required reintervention (3.3%). Estimated renal graft patency was 88.9% at 60 months. Left renal chimney grafts were most commonly at the 3-o'clock position (51.1%) at the ostium, traversing posteriorly to the 5- to 7-o'clock positions (55.5%) at the fabric edge. Right renal chimney grafts started most commonly at the 9-o'clock position (n = 17; 33.3%) and tended to traverse both anteriorly (11 to 1 o'clock; 39.2%) and posteriorly (5 to 7 o'clock; 29.4%) at the fabric edge. In the polar plane, the majority of renal chimney grafts (n = 83; 85.6%) traversed <90 degrees before reaching the proximal fabric edge. Grafts that traversed >90 degrees were independently associated with early type Ia endoleaks (odds ratio, 11.5; 95% confidence interval, 2.1-64.8) even after controlling for other device and anatomic variables. Polar orientation of the chimney grafts was not associated with graft kinking or compression (P = .38) or occlusion (P = .10). Takeoff angle of the renal arteries was the most significant predictor of chimney graft orientation. Caudally directed arteries (takeoff angle >30 degrees) were less likely to have implanted chimney grafts that traversed >90 degrees in polar angle (odds ratio, 0.09; 95% confidence interval, 0.01-0.55).Renal chimney grafts vary considerably in both starting position and their polar trajectory within the proximal seal zone. Grafts that traverse >90 degrees in polar angle within the seal zone may be at increased risk of early type Ia endoleaks and require more frequent imaging surveillance. Caudally directed renal arteries result in a more favorable polar geometry (eg, cranial-caudal orientation) with respect to endoleak risk and thus are more ideal candidates for parallel graft strategies.

    View details for PubMedID 29074111

  • Use of a proactive duplex ultrasound protocol for hemodialysis access. Journal of vascular surgery Itoga, N. K., Ullery, B. W., Tran, K., Lee, G. K., Aalami, O. O., Bech, F. R., Zhou, W. 2016; 64 (4): 1042-1049 e1

    Abstract

    Arteriovenous fistula (AVF) creation is the preferred approach for hemodialysis access; however, the maturation of AVFs is known to be poor. We established a proactive early duplex ultrasound (DUS) surveillance protocol for evaluating AVFs before attempted access. This study determined the effect of this protocol related to improving AVF maturation.From 2008 to 2013, 153 patients received new upper extremity AVFs and an early DUS surveillance protocol at a single academic institution. The protocol involved an early DUS evaluation before hemodialysis cannulation of the AVF at 4 to 8 weeks after AVF creation. A positive DUS result was identified as a peak systolic velocity of >375 cm/s or a >50% stenosis on gray scale imaging, along with decreased velocity in the outflow vein. Patients with positive DUS findings underwent prophylactic endovascular or open intervention to assist with AVF maturation. Nature of secondary interventions, as well as AVF patency and maturation, were assessed. Overall clinical outcomes and fistula patency were investigated.During the study period, 183 upper extremity AVFs were created in 153 patients, including 82 radiocephalic, 63 brachiocephalic, and 38 brachiobasilic AVFs. A mortality rate of 43% (n = 66) was observed in a median follow-up period of 34.5 months (interquartile range, 19.6-46.9). A total of 164 early DUS were performed at a median of 6 weeks (interquartile range, 3.4-9.6 weeks) after the initial creation. Early DUS showed nine AVFs were occluded and were excluded from further analysis. Hemodynamically significant lesions were found in 62 AVFs (40%); however, only 17 (11%) were associated with an abnormal physical examination. Positive DUS finding prompted a secondary intervention in 81% of the patients. Among those with positive early DUS findings, AVF maturation was 70% in those undergoing a secondary intervention compared with 25% in those not undergoing a prophylactic intervention (P = .011). Primary-assisted patency for AVFs with early positive and negative DUS findings were 83% and 96% at 6 months, 64% and 89% at 1 year, and 52% and 82% at 2 years, respectively (P < .001).Early DUS surveillance of AVFs before initial access is reasonable to identify problematic AVFs that may not be reliably detected on clinical examination. Although DUS criteria for AVFs have yet to be universally accepted, proactive early postoperative DUS interrogation assists in the early detection of dysfunctional AVFs and improvement of fistula maturation. Despite improved patency in those with positive DUS findings who undergo prophylactic secondary intervention, overall patency remains inferior to those without an abnormality detected on early DUS imaging.

    View details for DOI 10.1016/j.jvs.2016.03.442

    View details for PubMedID 27183858

  • SPY technology as an adjunctive measure for lower extremity perfusion JOURNAL OF VASCULAR SURGERY Colvard, B., Itoga, N. K., Hitchner, E., Sun, Q., Long, B., Lee, G., Chandra, V., Zhou, W. 2016; 64 (1): 195-201

    Abstract

    Lack of a reliable outcome measure often leads to excessive or insufficient interventions for critical limb ischemia (CLI). SPY technology (Novadaq Technologies Inc, Bonita Springs, Fla), widely adapted by plastic and general surgeons, uses laser-assisted fluorescence angiography (LAFA) to assess tissue perfusion. We sought to determine the role of SPY as an alternative, perhaps more reliable outcome measure for vascular interventions.All patients undergoing elective or urgent revascularization for claudication and CLI were prospectively recruited from June 2012 to August 2014. LAFA using SPY technology was performed before and after revascularization procedures under a standard Institutional Review Board-approved protocol. Quantitative measures of perfusion at plantar surfaces were analyzed and compared with ankle-brachial index.A total of 93 patients with claudication or CLI underwent LAFA before and after a revascularization procedure in the study period. The mean preoperative ankle-brachial index increased from 0.60 to 0.84 (P < .001) after a revascularization procedure. Plantar perfusion as measured by LAFA also improved significantly after intervention. Ingress, defined as the rate at which fluorescence intensity increases on the plantar surface during LAFA, increased from 7.1 to 12.4 units/s (P < .001). Peak perfusion, defined as the difference between the baseline and the peak of fluorescence intensity, increased from 97.1 and 143.9 units (P < .001). Egress, defined as the rate at which intensity diminishes after reaching peak perfusion, increased from 1.0 to 1.9 units/s (P = .035). Procedure-related digital embolization was also observed in several patients despite lack of an angiographic finding.This is the largest prospective study evaluating SPY technology in peripheral vascular interventions. Our study shows that SPY is a valuable tool in visualizing real-time procedural outcomes and providing additionally useful information on regional tissue perfusion. Further investigation is warranted to standardize outpatient use and to determine threshold values that predict wound healing.

    View details for DOI 10.1016/j.jvs.2016.01.039

    View details for Web of Science ID 000378562900027

    View details for PubMedID 26994959

  • Giant Abdominal Aortic Aneurysms: A Case Series and Review of the Literature VASCULAR AND ENDOVASCULAR SURGERY Ullery, B. W., Itoga, N. K., Lee, J. T. 2015; 49 (8): 242-246

    Abstract

    Giant abdominal aortic aneurysms (AAAs), defined as those measuring greater than 13.0 cm in transverse diameter, represent a rare clinical entity and present unique anatomic challenges.A retrospective review of a prospectively maintained aneurysm database from 2000 to 2013 was performed at a single academic referral center. Preoperative comorbid status, aneurysm characteristics, procedural details, and perioperative course were recorded for all patients.Four patients (male, n = 3) with a mean age of 75.2 years (range, 71-80 years) underwent open repair of giant AAAs. The mean AAA size was 14.4 cm (range, 13.2-15.5 cm). All giant AAAs were associated with neck length <10 mm and/or severe neck angulation. At a mean follow-up of 22 months, there has been 1 late death due to nonaneurysm-related causes.Due to anatomic limitation with currently available aortic endografts, giant AAAs have been traditionally repaired using a standard open surgical approach. The feasibility of endovascular aortic aneurysm repair (EVAR) with or without the use of adjunct techniques, including snorkel/chimney or fenestrated EVAR, has yet to be elucidated.

    View details for DOI 10.1177/1538574415617554

    View details for PubMedID 26647427

  • Safety and efficacy of antiplatelet/anticoagulation regimens after Viabahn stent graft treatment for femoropopliteal occlusive disease JOURNAL OF VASCULAR SURGERY Ullery, B. W., Tran, K., Itoga, N., Casey, K., Dalman, R. L., Lee, J. T. 2015; 61 (6): 1479-1488

    Abstract

    We aimed to determine the safety and efficacy of antiplatelet/anticoagulation regimens after placement of Viabahn stent graft (W. L. Gore & Associates, Flagstaff, Ariz) for the treatment of femoropopliteal occlusive disease.Clinical, angiographic, and procedural data for patients undergoing endovascular treatment of femoropopliteal occlusive disease using Viabahn covered stent grafts at a single institution between 2006 and 2013 were retrospectively reviewed. Graft patency and freedom from thrombolysis, major adverse limb event, and reintervention were determined by Kaplan-Meier analysis. The influence of relevant variables on clinical outcome was determined through univariate and multivariate Cox proportional hazards analyses.Viabahn stent grafts were placed in a total of 91 limbs in 61 patients (66% men; mean age, 69 ± 12 years) during the study period. Indication for intervention was either claudication (n = 59) or critical limb ischemia (n = 32), with the majority (70%) classified as TransAtlantic Inter-Society Consensus II C (n = 33) or D (n = 31) lesions. Mean follow-up was 38.3 months (range, 1-91 months). Postprocedural pharmacologic regimens included aspirin, clopidogrel, and warfarin (47%); indefinite aspirin and clopidogrel (46%); or aspirin and temporary clopidogrel (7%). Primary and secondary patency rates were 60%, 44%, and 36% and 95%, 82%, and 74% at 1 year, 3 years, and 5 years, respectively. Kaplan-Meier analysis demonstrated more aggressive antiplatelet/anticoagulation regimens to be associated with improved primary patency and freedom from reintervention. Cox proportional hazards analysis demonstrated TransAtlantic Inter-Society Consensus II D lesions, tobacco use, coronary artery disease, and smaller stent diameter to be independent risk factors for stent graft failure. Bleeding events were limited to those in the aspirin, clopidogrel, and warfarin group (11.6% [n = 5]; P = .052), although the majority of these events were not life-threatening, and only two cases required blood transfusion.Increasingly aggressive antithrombotic regimens after Viabahn stent graft placement trended toward improved overall clinical outcomes, although the marginal patency benefit observed with the addition of warfarin to dual antiplatelet therapy was tempered by an observed increased risk of bleeding complications. Longer term follow-up and multicenter studies are needed to further define optimal type and duration of antithrombotic therapy after endovascular peripheral interventions.

    View details for DOI 10.1016/j.jvs.2014.12.062

    View details for Web of Science ID 000355018500013

    View details for PubMedID 25704407

  • A Rising Generation of Diversity in the Vascular Surgery Workforce. Annals of vascular surgery Itoga, N. K., Woo, K., Bismuth, J., Bechara, C. F., Grenon, M., Mitchell, E., Zhou, W. 2015; 29 (7): 1484–86

    View details for PubMedID 26253044

  • Transposition of the left renal vein for the treatment of nutcracker syndrome in children: a short-term experience. Annals of vascular surgery Ullery, B. W., Itoga, N. K., Mell, M. W. 2014; 28 (8): 1938 e5-8

    Abstract

    Nutcracker syndrome is caused by compression of the left renal vein between the superior mesenteric artery and the aorta. Invasive surgical intervention for this pathologic entity is controversial, particularly in the pediatric population. We aim to describe our early clinical and operative experience with such patients.We report 3 cases of pediatric patients undergoing successful left renal vein transposition for the treatment of nutcracker syndrome.All 3 patients were female (age 9-17 years) and presented with a mean of 11.7 months of abdominal or left flank pain requiring chronic narcotic analgesia. Initial clinical presentations were associated with either hematuria or proteinuria. Diagnosis of nutcracker syndrome was supported in each case by an elevated renocaval pressure gradient and/or axial imaging demonstrating mesoaortic compression of the left renal vein. All patients underwent open surgical repair, which included left renal vein transposition, liberation of the ligament of Treitz and associated adhesions, as well as excision of periaortic nodal tissue (mean hospital length of stay 5.7 days). After mean follow-up of 13 months, all patients report complete resolution of symptoms and hematuria/proteinuria.Transposition of the left renal vein is a safe and effective treatment for nutcracker syndrome in appropriately selected pediatric patients. Further experience and long-term follow-up are warranted to better evaluate the sustained efficacy of this procedure in this unique patient population.

    View details for DOI 10.1016/j.avsg.2014.07.022

    View details for PubMedID 25111949