Rajeev Dayal

An analysis of the outcomes of a decade of experience with lower extremity revascularization including limb salvage, lengths of stay, and safety

BACKGROUNDnDemographic and practice modality changes during the past decade have led to a substantial shift in the management of peripheral vascular disease. This study examined the effect of these changes using large national and regional data sets on procedure type, indications, morbidity, and on the primary target outcome: limb salvage.nnnMETHODSnNational Inpatient Sample (NIS) data sets and New York (NY) State inpatient hospitalizations and outpatient surgeries discharge databases from 1998 through 2007 were used to identify hospitalizations for lower extremity revascularization (LER) and major amputations. Patients were selected by cross-referencing diagnostic and procedural codes. Proportions were analyzed by chi(2) analysis, continuous variables by t test, and trends by the Poisson regression.nnnRESULTSnThe national per capita (100,000 population, age >40 years) volume of major amputations decreased by 38%. The volume for national and regional use of endovascular LER doubled. The volume of open LER decreased by 67% from 1998 through 2007. Ambulatory endovascular LER grew in NY State from 7 per capita in 1998 to 22 in 2007. Interventions declined by 20% (93 to 75) for critical limb ischemia (CLI) but increased by nearly 50% for claudication. Outpatient data analysis revealed a fivefold increase in vascular interventions for CLI and claudication. Nationally, endovascular LER interventions quadrupled (8% to 32%) for CLI and doubled (26% to 61%) for claudication. A parallel reduction occurred in major amputations for patients with CLI (42% to 30%), for other PAD diagnoses (18% to 14%), and for claudication (0.9% to 0.3%). Although surgical interventions for CLI declined significantly for octogenarians from 317 to 240, outpatient interventions increased for CLI, claudication, and other diagnoses in all age groups. Comorbidities for patients treated in 2006 were substantially greater than those of a decade ago. For most procedures, cardiac and bleeding complications have significantly decreased during the last decade. Length of stay (LOS) declined from 9.5 to 7.6 days and the percentage of short (1-2 day) hospitalizations increased from 16% to 35%.nnnCONCLUSIONnAlthough patients today, whether treated for claudication or CLI, have more comorbidities, the rates of amputation, the procedural morbidity and mortality, and LOS have all significantly decreased. Other variables, including changes in medical management and wound care, undoubtedly are important, but this change appears to be largely due to the widespread and successful use of endovascular LER or to earlier intervention, or both, driven by the safety of these techniques.

Lesion types and device characteristics that predict distal embolization during percutaneous lower extremity interventions

OBJECTIVEnDistal embolization (DE) during percutaneous lower extremity revascularization (LER) may cause severe clinical sequelae. To better define DE, we investigated which lesion types and treatment modalities increase the risk for embolization.nnnMETHODSnA prospective registry of LER from 2004 to 2009 was reviewed. All cases with runoff evaluated before and after intervention were included. Angiograms and operative reports were reviewed for evidence of DE. Interventions included percutaneous transluminal angioplasty (PTA), with or without stent placement, and atherectomy with four different devices. Chi-square analysis and Fishers exact test were used to assess significance. Patency rates were calculated using Kaplan-Meier analysis and compared using log-rank analysis.nnnRESULTSnThere were 2137 lesions treated in 1029 patients. The embolization rate was 1.6% (34 events). Jetstream (Pathway, Kirkland, Wash) and DiamondBack 360 (Cardiovascular Systems Inc, St Paul Minn) devices had a combined embolization rate of 22% (8 of 36), 4 of 18 (22%) in each group, which was significantly higher than with PTA alone (5 of 570, 0.9%), PTA and stent (5 of 740, 0.7%), SilverHawk (ev3, Plymouth, Minn) atherectomy (14 of 736, 1.9%), and laser atherectomy (2 of 55, 3.6%; P < .001). There was a significantly higher rate of embolization for in-stent restenosis (6 of 188, 3.2%) and chronic total occlusions (15 of 615, 2.4%) compared with stenotic lesions (13 of 1334, 0.9%; P = .01). The embolization rate was significantly higher in Transatlantic Inter-Society Consensus (TASC) II C and D lesions compared with TASC A and B lesions (P = .018). DE rates were not affected by preoperative runoff status (P = .152). Patency was restored at the completion of the procedure in 32 of 34 cases of DE. The 24-month primary patency, assisted primary patency, and secondary patency in the DE group was 54.0% ± 11.9%, 70.0% ± 10.3%, and 73.2% ± 10.3%, respectively, and was 44.4% ± 1.7%, 61.5% ± 1.7%, and 68.2% ± 1.6%, respectively, when embolization did not occur (P > .05). Limb salvage was 72.6% ± 3.1% in lesions in which no DE occurred vs 83.3% ± 15.2% in lesions in which DE occurred (P = .699).nnnCONCLUSIONSnDE is a rare event that occurs more often with the Jetstream and DiamondBack 360 devices. In-stent and complex native lesions are at higher risk for DE. DE is typically reversible with endovascular techniques and has no effect on patency rates and limb salvage.

Midterm outcomes after treatment of type II endoleaks associated with aneurysm sac expansion

Purpose To examine the outcomes following interventions for type II endoleaks in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR). Methods A retrospective review was conducted of all patients who underwent treatment for type II endoleak from July 2001 to September 2010 in a single center. In this time period, 29 (4.7%) patients (22 men; mean age 78.6 years, range 54–87) were identified as having a type II endoleak and enlargement of the aneurysm sac, meeting the criterion for treatment. All patients had at least one attempted percutaneous intervention. Patients were followed both clinically and radiographically, with computed tomographic angiography every 3 to 12 months, over a follow-up period that ranged from 1 to 10 years (mean 3.5). Results Forty-eight interventions were performed on the 29 patients. Of these, 15 (56%) patients underwent multiple (2–4) procedures. Of the 11 endoleaks with an isolated inferior mesenteric artery identified as the source, initial success for transarterial embolization at 2 years was 72%, with 2 of the failures having successful secondary interventions. For the 18 endoleaks with a lumbar source, the success of the initial intervention was 17% at 2 years; repeated embolization attempts produced a 40% secondary success rate. Seven (24%) patients had continued endoleak despite multiple treatment attempts; 3 ultimately required elective aortic graft explantation. There were no ruptures or deaths during the study period. In a comparison of type II endoleak patients who had stable aneurysm sacs and those who had persistent sac expansion, the only significant differences in preoperative anatomical characteristics were a lower prevalence of mural thrombus (p=0.036) and longer right iliac arteries (p=0.012) in the group with sac expansion. Independent predictors of type II endoleak were mural thrombus (p<0.001), patent lumbar arteries (p=0.004), aneurysm length (p=0.011), and iliac artery length (p=0.004) Conclusion This study demonstrates that most patients require multiple reinterventions to treat type II endoleaks; specifically, lumbar artery embolization carries a low midterm success rate.

Endovascular management as first therapy for chronic total occlusion of the lower extremity arteries: comparison of balloon angioplasty, stenting, and directional atherectomy.

Purpose To evaluate the role of endovascular therapy in the management of infrainguinal arterial chronic total occlusions (CTOs). Methods Data on all patients with CTOs treated at a single center from 2004 to 2010 were extracted from a prospectively maintained database for retrospective analysis. Patient demographics, angiographic studies, noninvasive vascular test results, and clinical outcomes were evaluated. In this time frame, 481 patients (283 men; mean age 71.7±11.5 years, range 52–85) with claudication (n=177) or critical limb ischemia (CLI, n=304) were treated for 688 CTOs. Lesions were segregated according to location [SFA (n=193), popliteal (n=67), tibial (n=217), and multilevel (n=211)] and analyzed based on treatment mode (angioplasty, angioplasty with stenting, or atherectomy) and clinical indication. Primary patency, assisted primary patency, and secondary patency, as well as limb salvage rates for CLI patients, were calculated. Results At 2 years in claudicants with CTOs confined to the SFA, primary patency ranged from 44% to 58% and secondary patency to 92% depending on treatment type; there were no significant differences among the treatments. However, in CLI patients with SFA CTOs, atherectomy produced better outcomes at 2 years (p=0.002 for primary and p=0.012 for secondary patency) than angioplasty alone. The limb salvage rates ranged from 73% to 91% (no differences among treatment types). In diabetics, CTOs treated with angioplasty and stent had improved secondary patency rates over angioplasty alone. Conclusion The endovascular management of CTO results in reasonable primary patency; moreover, secondary patency at 2 years is excellent. Endovascular therapy should be the first-line option for many patients with peripheral artery disease, including those with CLI, claudicants with poor bypass conduit, or patients at high medical risk for surgery. The presence of CTOs does not appear to change these recommendations. Although multiple reinterventions may be required, endovascular therapies can be considered a primary therapy for many patients with CTO.

Embolization of Renal Artery Aneurysm and Arteriovenous Fistula A Case Report

A renal artery aneurysm with an associated arteriovenous fistula in a native kidney has been reported infrequently in the literature. Management depends on size, location, and the patients physiological condition. We describe a case in which endovascular therapy was used to successfully exclude both aneurysm and fistula. This report describes a 13-centimeter renal artery aneurysm with arteriovenous fistula originating from an isolated branch of the renal artery. Coil-embolization resulted in thrombosis of the aneurysm and fistula while preserving parenchymal perfusion. Coil embolization is an alternative to surgery for coexistent renal artery aneurysm and arteriovenous fistula arising from a branch of adequate length for placement of embolic coils. Successful treatment is not limited by aneurysm size or presence of arteriovenous connection.

Dynamic diffuse optical tomography imaging of peripheral arterial disease.

Peripheral arterial disease (PAD) is the narrowing of arteries due to plaque accumulation in the vascular walls. This leads to insufficient blood supply to the extremities and can ultimately cause cell death. Currently available methods are ineffective in diagnosing PAD in patients with calcified arteries, such as those with diabetes. In this paper we investigate the potential of dynamic diffuse optical tomography (DDOT) as an alternative way to assess PAD in the lower extremities. DDOT is a non-invasive, non-ionizing imaging modality that uses near-infrared light to create spatio-temporal maps of oxy- and deoxy-hemoglobin in tissue. We present three case studies in which we used DDOT to visualize vascular perfusion of a healthy volunteer, a PAD patient and a diabetic PAD patient with calcified arteries. These preliminary results show significant differences in DDOT time-traces and images between all three cases, underscoring the potential of DDOT as a new diagnostic tool.

Development and Implementation of an Introductory Endovascular Training Course for Medical Students

BACKGROUNDnEndovascular simulation has been promoted as an educational tool for trainees to practice procedures in a safe environment and improve basic technical skills. We sought to determine whether an established endovascular training course for medical students could increase technical proficiency, enhance interest in vascular surgery, and be implemented at another academic institution.nnnMETHODSnAt Center A, medical students participated in an eight-week elective course with a structured curriculum comprised of weekly mentored simulator sessions and didactic teachings. A similar course was developed at Center B to train a similar cohort of students using the same high-fidelity simulator. Demographics and survey data, including interest in vascular surgery, were obtained, and pre- and postcourse graded simulator sessions on renal stent or iliac/superficial femoral artery stent modules were conducted. Performance was assessed by expert observers using a standardized global endovascular rating scale and objective procedural metrics collected from the simulator.nnnRESULTSnSeventy-seven medical students (41 at Center A and 36 at Center B; 56 men and 21 women) completed the course from 2007 to 2009. Parameters measured on the standardized global endovascular rating scale, including angiography skills, wire handling, and interventional criteria as well as simulator-generated metrics, significantly improved from pre- to postcourse values for both groups of medical students at the two institutions (p < 0.05). More than 94% of the students agreed or strongly agreed that the simulation course increased their interest in vascular surgery.nnnCONCLUSIONnA simulation-based endovascular course provides an educational tool that improves basic technical performance and increases interest in vascular surgery among medical students. This simple educational module appears to be transferable and adaptable at another institution with minimal modification to produce similar results.

Endoluminal recanalization in a patient with phlegmasia cerulea dolens using a multimodality approach-a case report.

Phlegmasia cerulea dolens is a limb-threatening form of deep venous thrombosis and should be treated aggressively. The authors report a patient who presented with iliocaval and femoral deep venous thrombosis and posed an additional therapeutic challenge based on a recent history of heparin-induced thrombocytopenia. Catheter-directed pharmacologic thrombolysis and balloon venoplasty were applied in treatment. The direct thrombin inhibitor argatroban was used in place of heparin for concurrent anticoagulation. This multimodality endovascular approach (chemical and mechanical interventions) was successful in relieving the venous occlusion and salvaging the limb, while maintaining appropriate treatment for heparin-induced thrombocytopenia.

High bifurcation of brachial artery with acute arterial insufficiency: a case report.

The upper extremity arterial system shows a large number of variations in the adult human body. Most of these variations occur in either the radial or ulnar artery; brachial artery variations are less common. Because the upper extremity is a frequent site of injury and various surgical and invasive procedures are performed in this region, it is of utmost importance to be aware of arterial variations. We report a case of a high bifurcation of the brachial artery presenting with acute ischemia secondary to an embolic event. The anomaly was identified, and the ischemia was successfully resolved with embolectomy.

Determining Criteria for Predicting Stenosis With Ultrasound Duplex After Endovascular Intervention in Infrainguinal Lesions

BACKGROUNDnStudies examining duplex surveillance of lower extremity bypass grafts have defined a role for guiding graft re-intervention. The goal of this study is to determine the utility of duplex scanning to detect angiographic restenosis after endovascular therapy in patients with infrainguinal arterial disease.nnnMETHODSnA prospective registry including all patients treated for lower extremity atherosclerotic disease between February 2004 and September 2008 was established. Patients were followed up with duplex ultrasound at 1, 3, 6, 12 months, and then annually. Patients receiving repeat angiograms were identified and angiogram and duplex data were abstracted. Velocity ratios (Vr) were calculated for each lesion by dividing the peak velocity within the lesion by the peak velocity proximal to the lesion. Logarithmic regression and receiver operator characteristic (ROC) curve analyses were used.nnnRESULTSnRepeat angiograms were performed on 345 lesions in 143 patients, and 254 lesions in 103 patients had a corresponding duplex ultrasound. Indications for the initial intervention were claudication (n = 62, 43.4%), rest pain (n = 23, 16.1%), and tissue loss (n = 58, 40.5%). A total of 178 superficial femoral artery (SFA) lesions, 59 popliteal lesions, and 17 tibial lesions were identified by surveillance duplex in 103 patients. In all, 70.5% of the intervened vessels that were studied were nonstented and the remaining 29.5% were stented. A total of 65% of the patients had diabetes. On determining correlations for peak systolic velocity (PSV) as measured by duplex ultrasound with degree of angiographic stenosis, strong correlation coefficients for SFA disease (R² = 0.84) and popliteal disease (R² = 0.88) were found. However, poor correlation was found in patients with tibial disease. When analyzing the lesions on the basis of Vr < 2.0, 11 of 86 (12.8%) had >70% angiographic stenosis. In lesions with ratios from 2 to 2.5, 12 of 13 (92.3%) had >70% angiographic stenosis and in lesions with ratios >2.5, 69 of 75 (92.0%) had >70% angiographic stenosis. ROC curve analysis showed that to detect ≥ 70% stenosis in the SFA, a PSV ≥ 204 cm/sec had a sensitivity of 97.6% and specificity of 94.7%. To detect ≥ 70% stenosis in the overall femoropopliteal region, a PSV ≥ 223 cm/sec had a sensitivity of 94.1% and specificity of 95.2%.nnnCONCLUSIONSnDuplex ultrasound surveillance correlates to the degree of angiographic stenosis on the basis of PSV in the SFA and popliteal region. Correlation in the tibial vessels is poor. Vr > 2.0 appear to correlate to angiographic stenosis of > 70%. ROC analysis shows that PSV can have sufficiently high sensitivity and specificity to predict angiographic stenosis in the femoropopliteal region.