Mark C. Bates

Angioplasty/stenting of the superior mesenteric artery and celiac trunk: early and late outcomes.

Purpose: To analyze the early results and durability of angioplasty/stenting of the superior mesenteric artery (SMA) and celiac trunk (CT). Methods: Twenty-two patients (19 women; mean age 69.2 years, range 52–88) with 24 symptomatic SMA or CT stenotic lesions were treated with dilation/stenting over a recent 4.5-year period. Two patients had lesions in both the SMA and CT treated. Clinical follow-up and duplex exams were done to evaluate long-term patency. Kaplan-Meier life-table analyses estimated the freedom from recurrent stenosis and recurrent symptoms, as well as survival rates. Results: The initial technical and clinical success rates were 96% (23/24) and 95% (21/22), respectively, with no perioperative mortality or major morbidity. During a mean follow-up of 26 months (range 1–54), the primary late clinical success rate was 61% (11/18; 4 lost to follow-up), and freedom from recurrent stenosis (≥70%) was 30% (6/20). The freedom from recurrent stenosis at 1, 2, 3, and 4 years were 65%, 47%, 39%, and 13%; freedom from recurrent symptoms was 67% at all 4 intervals. The survival rates were 93%, 93%, 80%, and 53% at 1 to 4 years, respectively. Conclusions: Angioplasty/stenting of SMA and CT stenoses has a high initial technical success rate and acceptable early and late clinical outcomes; however, it is associated with a high incidence of late restenosis based on strict Doppler criteria.

Angioplasty and Stenting versus Carotid-Subclavian Bypass for the Treatment of Isolated Subclavian Artery Disease

PURPOSE To compare the results of a large series of percutaneous transluminal angioplasty (PTA)/stenting procedures in the subclavian artery with the results of a series of carotid-subclavian bypass grafts (CSBG) performed at the same institution for subclavian artery disease. METHODS Between 1993 and 2006, 121 patients (43 men; mean age 63 years, range 38-85) underwent subclavian artery PTA/stenting and were compared to a group of 51 patients (29 men; mean age 62 years, range 46-75) with isolated subclavian artery occlusive disease treated with CSBG using polytetrafluoroethylene grafts. Graft or PTA/stenting patency was determined clinically and confirmed by Doppler pressures and/or duplex ultrasound/angiography. The cumulative patency and overall survival rates were calculated using the life-table method. RESULTS The mean follow-up for the PTA/stent group was 3.4 years versus 7.7 years for the CSBG group. The technical success rate for the CSBG group was 100% versus 98% (119/121) for the PTA/stent group. The overall perioperative complication rate in the stent group was 15.1% (18/119: 11 minor and 7 major complications) versus 5.9% (3/51: 2 phrenic nerve palsy and 1 myocardial infarction) in the bypass group (p=0.093). There was no perioperative stroke or mortality in the CSBG group. The major perioperative complications in the stent group included 4 thromboembolic events, 1 congestive heart failure, 1 reperfusion arm edema, and 1 pseudoaneurysm. There was 1 perioperative death in the stent group. The 30-day patency rate was 100% for the bypass group and 97% (118/121) for the PTA/stent group. The primary patency rates at 1, 3, and 5 years were 100%, 98%, and 96% for the CSBG group versus 93%, 78%, and 70% for the stent group, respectively (p<0.0001). Freedom from symptom recurrence was also statistically superior in the bypass group versus the stent group (p<0.0001). There were no significant differences in the survival rates between both groups at any time point (p=0.322). CONCLUSION Both CSBGs using PTFE grafts and subclavian PTA/stenting are safe, effective, and durable; however, CSBG is more durable in the long term. PTA/stenting of the subclavian artery should be the procedure of choice for high-risk patients; however, CSBG should be offered to good-risk surgical candidates who may be seeking a more durable procedure.

Acute profound thrombocytopenia following C7E3 Fab (abciximab) therapy: Case reports, review of the literature and implications for therapy

Platelets play a crucial role in the ischemic complications of percutaneous coronary procedures. The recent availability of C7E3 Fab (Abxiximab or ReoPro™), a chimeric monoclonal antibody Fab fragment directed against the platelet glycoprotein IIb/IIIa receptor, has reduced abrupt closure and other adverse events and lessened the need for revascularization procedures. As the use for this drug has increased, rare cases of severe thrombocytopenia have been revealed. From August 1995 to June 1997, 452 patients at Charleston Area Medical Center who underwent percutaneous coronary revascularization procedures and were treated with abciximab were evaluated for the development of severe thrombocytopenia (i.e., platelet count less than 20,000 within 48 hr of treatment). A review of published reports of severe thrombocytopenia was also reviewed. A review of published reports of abciximab‐induced severe thrombocytopenia, as well as our three cases, reveals that: 1) the incidence is less than 0.7%; 2) the nadir platelet count (range 1,000–16,000) was noted within 2–31 hr after abciximab infusion; 3) the platelet count increases to greater than 100,000 within 12 days in all patients; 4) bleeding episodes were treated with platelet transfusion with an improvement in platelet count within 24 hr in all patients in whom they were given; and 5) in the one patient treated with γ globulin alone, no significant rise in platelet count was noted. Acute severe thrombocytopenia can occur after ReoPro™ administration. Its development is not predictable and may occur within 2 hr of administration. Thrombocytopenia, therefore, requires consideration in every patient treated with this drug. It appears prudent to obtain a platelet count 2 hr after initiating ReoPro™. If thrombocytopenia develops, then the drug can be stopped in a timely manner and platelet transfusion can be given. Am. J. Hematol. 61:205–208, 1999.

Significant reduction in systolic blood pressure following renal artery stenting in patients with uncontrolled hypertension: Results from the HERCULES trial†

Background: Atherosclerotic renal artery stenosis (ARAS) causes hypertension (HTN) and threatens renal function (RF). The HERCULES Trial is a prospective, multicenter trial of renal stenting in patients with uncontrolled HTN and ARAS evaluating the safety and effectiveness of the RX Herculink Elite Renal Stent System (Abbott Vascular, Santa Clara, CA). Methods: A total of 202 patients (241 total lesions; 78 bilateral lesions) were enrolled between August 2007 and October 2009. The primary endpoint was 9‐month binary restenosis determined by duplex ultrasound and/or angiography. Secondary endpoints included changes in blood pressure, antihypertensive medications, and RF between baseline and 9 months. Brain natriuretic peptide (BNP) was measured at baseline, 24 hr and 30 days postprocedure. Results: Mean systolic blood pressure (SBP) at baseline was 162 mm Hg. Nearly 70% of patients were receiving three or more antihypertensive medications (mean 3.4 medications per patient). Baseline serum creatinine was 1.2 ± 0.4 and 61.5% of subjects had estimated glomerular filtration <60. The restenosis rate was 10.5% at 9 months. The study device, procedure, and clinical success rates were 96.0, 99.2, and 98.0%, respectively. Freedom from major adverse events was 94.8%. At 9 months, the mean SBP significantly decreased (mean 145, paired t test P < 0.0001) after stenting with no change in medications. There was no correlation between SBP reduction and baseline BNP or BNP reduction. Conclusions: HERCULES demonstrates clinically and statistically significant SBP reduction in patients with uncontrolled HTN, low in‐stent restenosis, and complication rates. This study highlights that when appropriate patients are selected for renal artery stenting, impressive reductions in blood pressure may be anticipated. Although the magnitude of absolute reduction in SBP was related to baseline SBP, elevated baseline BNP levels were not predictive of reduction in SBP. Further studies for predictors of clinical response following percutaneous renal revascularization are needed.

Factors affecting long-term survival following renal artery stenting

Introduction: This study defines clinical variables at the time of renal artery stenting that may be predictors of long‐term all‐cause mortality. Methods: The data are derived from the single operator, single center, renal stent retrospective study (SOCRATES) and includes a review of 748 (336 men, 412 women) consecutive symptomatic patients with de novo atherosclerotic renal artery stenosis treated over an 11‐year period. All patients had clinical indications for renal revascularization, including, but not limited to; suboptimal control of hypertension, chronic kidney disease, and cardiac disturbance syndromes. Clinical variables at the time of the index procedure were evaluated as predictors of all‐cause mortality using multivariate analysis. Mortality data were derived from hospital records and formal queries of the State Department of Health and Human Services, Health and Vital Statistics Division database. Results: In‐hospital, 30‐day and 6‐month mortality rates were 0.5, 2.0, and 6.3%, respectively. Overall patient survival at years 1, 5, and 10 was 91.2, 66.6, and 40.9%, respectively. Comorbid conditions, including chronic obstructive pulmonary disease and congestive heart failure, were independently associated with increased mortality. There were incremental changes in mortality in patients with baseline azotemia, [preprocedure serum creatinine (sCr) 1.5–2.09 mg/dL hazard ratio 1.52; sCr >2.5 mg/dL hazard ratio 3.39]. Therapy with lipid lowering agents offered a survival advantage (hazard ratio 0.69, P = 0.0.049); however, this study was not designed to evaluate a “protective effect” of lipid lowering medications. Conclusions: Patients with chronic obstructive pulmonary disease and congestive heart failure undergoing renal artery stent revascularization have a poor long‐term prognosis. Baseline azotemia is the strongest independent predictor of all cause mortality, with more than 70% of patients with marked azotemia (sCr >2.5) dead at 5 years.

Short- and long-term outcomes of percutaneous transluminal angioplasty/stenting of renal fibromuscular dysplasia over a ten-year period.

OBJECTIVES The purpose of this study was to evaluate short and long-term outcomes of percutaneous transluminal intervention in patients with symptomatic renal artery stenosis due to fibromuscular dysplasia (RAFMD) and/or the combination of RAFMD with aorto-ostial atherosclerotic disease. METHODS A retrospective analysis of all patients with renal artery RAFMD who underwent transcatheter therapy between January 1999 and December 2009 was performed. Blood pressure (BP) measurement, number of BP medications, and hypertension defined by a systolic BP >140 ± diastolic BP >90 were recorded. Renal function was defined by estimated glomerular filtration rate (eGFR). Restenosis was defined by stenosis >60% and was determined by renal artery duplex and/or angiography. Freedom from event (restenosis, renal failure, or recurrent hypertension) was performed using life table analysis. RESULTS Forty-three procedures were performed on 35 patients with RAFMD. Thirty-two patients (91%) were women, with mean age of 61.9 years old. Technical success was 100% with adjunctive stent placement required in the FMD segment for dissection in 1 patient (2.3%) and in the non-FMD aorto-ostial atherosclerotic lesion in 4 patients (9.3%). Short-term outcomes: the majority (69%) had an immediate clinical benefit for hypertension, 6% were cured without BP medications, and 63% improved with less than or equal to preoperative BP medications. Postintervention, 17% remained at moderately reduced renal function (<60), whereas the percent above >60 mL/minute eGFR increased significantly (from 51% to 69%; P = .002). For the entire cohort, renal function (mean eGFR) significantly increased from 71.9 mL/minute + 5.8 to 80.8 mL/minute + 5.2 (P = .007). Long-term outcomes: freedom from recurrent or worsening hypertension (>140 systolic blood pressure [SBP] and >90 diastolic blood pressure [DBP]) was (93%, 75%, and 41%) and freedom from reduced renal function (eGFR <30 mL/minute) was (100%, 95%, and 64%) at 1, 5, and 8 years, respectively. Patients with reduced baseline renal function (<60 mL/minute) and combined atherosclerotic disease were more likely to experience long-term reduced renal function (eGFR <30 mL/minute; P = .003). Primary and assisted primary patency was (95%, 71%, and 50%) and (100%, 100%, and 100%) at 1, 5, and 9 years, respectively. CONCLUSION Renal angioplasty is a safe and durable modality for treating RAFMD with favorable short and long-term clinical outcomes. Patients with combined atherosclerotic disease and FMD were older and were more likely to have declining renal function over time. Early intervention may be imperative to achieve possible cure of hypertension.

An Update on Endovascular Therapy of the Lower Extremities

Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.

Predictors of percutaneous access failure requiring open femoral surgical conversion during endovascular aortic aneurysm repair

OBJECTIVE To determine predictors of percutaneous (PEVAR) access failure requiring conversion to an open approach (OEVAR) during endovascular aortic aneurysm repair (EVAR). METHODS A single-center retrospective review of all EVAR patients from January 2009 through June 2011 with multivariate analysis of clinical and anatomic variables that could impact access outcome was conducted. Target vessel calcification was categorized as mild, moderate, or severe based on circumferential calcium arc (<⅓, ⅓ to ½, and >½ respectively), dyslipidemia (defined as low-density lipoprotein >130 mg/dL or receiving lipid lowering medication), and obesity (defined as body mass index [BMI] >30). RESULTS We investigated 400 access sites for 200 patients who underwent EVAR. The study cohorts characteristics included an average age of 72.8 ± 9.0 years, vessel size of 9.6 ± 1.8 mm, sheath size of 17.1 ± 3.0 Fr, BMI of 27.6 ± 5.3, and estimated glomular filtration rate of 68.5 ± 24.2 mL/min. Comorbidities included dyslipidemia in 129 patients (64.5%) and diabetes in 54 patients (27%). There were 132 OEVAR (66 patients), two mixed OEVAR with contralateral PEVAR (one patient), and 266 (133 patients) PEVAR approaches. Use of PEVAR increased over time (45.5% [2009], 77.8% [2010], and up to 88.5% [2011]; P = .001) while conversions decreased (24.3% [2009], 8.7% [2010], and 4.3% [2011]; P = .001]. More OEVAR patients (35.8%) stayed longer than 3 days compared with 21.1% for PEVAR (P = .028). For the 266 PEVAR approaches, 32 access sites (12.0%) had to be converted. Severely calcified arteries were most predictive of conversion (odds ratio [OR], 36.4; P < .001). Year of procedure (2010; OR, 0.17; P = .001; 2011, OR, 0.20; P = .049), female gender (OR, 3.1; P = .017), moderately calcified arteries (OR, 2.5; P = .085), and age (OR, 2.3 [per decade]; P = .002) were all also significant. Vessel size, sheath size, and BMI were found to be nonsignificant predictors of conversion. CONCLUSIONS PEVAR was found to be safe, reliable, and feasible. Several factors, including learning curve, vessel calcification, age, and female gender predicted conversion of PEVAR to OEVAR.

Ten-year experience with renal artery in-stent stenosis

BACKGROUND Atherosclerotic renal artery stenosis (RAS) is the most common cause of secondary hypertension. Renal stenting has become the treatment of choice for RAS in most centers. Primary patency of RAS is well defined, but limited data are available on outcomes of secondary interventions for treatment of in-stent restenosis. METHODS This was a retrospective analysis of a 10-year experience with renal artery stenting in patients presenting with recurrent symptomatic stenosis. End points included freedom from tertiary procedures, change in baseline renal function by ≥20% measured by estimated glomerular filtration rate (eGFR), patency confirmed by duplex imaging, long-term hypertension response, freedom from hemodialysis, and survival. RESULTS We reviewed 948 patients with 1150 treated renal arteries. Of these, 107 patients (122 renal stents) returned with symptomatic in-stent restenosis and required reintervention (target vessel revascularization [TVR] rate, 10.6%): 97% had recurrent or worsening hypertension, and 67% had worsening renal function. There were 69 women (64%) and 38 men (35%) with an average age of 68.9 years. Mean follow-up was 35.5 months (range, 1.0-104.7 months) for patency and 37.7 months (range, 0.03-100.9 months) for renal function (creatinine). Secondary interventions included 27 percutaneous transluminal angioplasties (PTAs), 10 PTAs with cutting balloon, 77 repeat renal artery stenting, and 8 placements of drug-eluting stents (DES). Twenty-five of the 122 arteries (20%) required tertiary interventions in 23 patients, a significantly higher TVR rate vs de novo interventions (11%; P = .003). Freedom from tertiary interventions at 60 months was similar among treatment groups undergoing PTA (66%), cutting balloon (100%), stent (80%), and DES (75%; P = .348). Seventeen (16%) had an increase of >20%, 50 (47%) had a decrease of >20%, and 30 (28%) had no change in renal function. Ultimately 25 (23%) remained or progressed to renal failure (eGFR < 30%), and 8 required hemodialysis. The survival rate was 73% at 5 years. Mean follow-up for long-term hypertension response was 3.2 years, with 56% improved, 28% with no improvement or deterioration, 16% without long-term data available, and no patients cured. CONCLUSIONS Secondary interventions for renal in-stent restenosis had higher TVR vs de novo renal stents in this large series (21% vs 11%; P = .003). Definitive recommendations on the best secondary treatment strategy cannot be made because a medical treatment control group was not available for comparison.

Factors influencing the need for target vessel revascularization after renal artery stenting.

Purpose: To provide additional insight into factors that may be associated with the need for target vessel revascularization (TVR) following de novo renal artery stenting during long-term follow-up. Methods: A retrospective chart and database review was conducted to analyze the progress of all patients with de novo symptomatic renal artery stenosis who underwent stent-supported angioplasty under the auspices of the Single Operator, Single Center, Renal Stent Retrospective Study (SOCRATES). The records review identified 782 patients who were enrolled in the study between 1993 and 2004; after excluding 34 (4.5%) patients (lost to follow-up or inadequate data), 748 consecutive patients (412 women; mean age 70.7±9.7 years, range 37–92) were suitable for longitudinal analysis. The need for TVR was based on strict clinical criteria (≥20% rise in serum creatinine, worsening hypertension, and/or recurrent flash pulmonary edema), and all patients underwent multidisciplinary evaluation before stenting and during follow-up. Results: Follow-up spanned a mean 45.8±26.5 months. TVR was needed in 88 (10.03%) of 877 arteries and was best predicted by patient age ≤67 years (OR 2.91, p=0.0001), stent diameter ≤5.0 mm (OR 2.31, p=0.001), solitary functioning kidney (OR 2.01, p=0.048), history of lower extremity peripheral artery disease (OR 1.87, p=0.008), and antecedent history of stroke (OR 1.73, p=0.026). Conclusion: Renal artery stenting appears to be durable, with only 10% of stented arteries requiring TVR during clinically-based long-term follow-up. Arteries with a final stent diameter ≤5.0 mm were more than twice as likely to need TVR, as were patients with a solitary kidney. The authors acknowledge that clinical recurrence is not a surrogate for ultrasound surveillance after renal artery stenting, so prospective controlled trials will be needed to determine risk factors for restenosis.