Journal of vascular and interventional radiology : JVIR, 2017
To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patient... more To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patients who have undergone thoracic stent-graft placement for type B aortic dissection. The study included 62 patients (45 male, 17 female) aged 26-80 years (mean age, 58.1 y) who underwent thoracic endovascular aortic repair for type B aortic dissection at a single institution between January 2005 and May 2015. Mean age of aortic dissections was 5.3 months (range, 0.1-73.3 mo). Maximum aortic diameter at presentation was 41.7 mm ± 8.3. The follow-up period ranged from 3 to 104 months (mean, 27.1 mo). Computed tomographic (CT) angiography studies were reviewed to identify FL diameter enlargements > 5 mm at different levels along and distal to the stent graft. Imaging findings and clinical variables were investigated to determine their correlation with FL enlargement. No significant difference was found between the ages of aortic dissections in patients with and without FL enlargement (P = ....
Randomized clinical trials have not shown an additional clinical benefit of renal artery stent pl... more Randomized clinical trials have not shown an additional clinical benefit of renal artery stent placement over optimal medical therapy alone. However, studies of renal artery stent placement have not examined the relationship of albuminuria and treatment group outcomes. The CORAL study (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) is a prospective clinical trial of 947 participants with atherosclerotic renal artery stenosis randomized to optimal medical therapy with or without renal artery stent which showed no treatment differences (3(5.8% and 35.1% event rate at mean 43-month follow-up). In a post hoc analysis, the study population was stratified by the median baseline urine albumin/creatinine ratio (n=826) and analyzed for the 5-year incidence of the primary end point (myocardial infarction, hospitalization for congestive heart failure, stroke, renal replacement therapy, progressive renal insufficiency, or cardiovascular disease- or kidney disease-related death), for ...
We report our experience with Guenter Tulip filter placement indications, retrievals, and procedu... more We report our experience with Guenter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Guenter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Guenter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.
Journal of the American College of Cardiology, 2015
Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy w... more Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy with medical therapy alone have not shown any benefit of stent placement. However, debate continues whether patients with extreme pressure gradients, stenosis severity, or baseline blood pressure benefit from stent revascularization. The study sought to test the hypothesis that pressure gradients, stenosis severity, and/or baseline blood pressure affects outcomes after renal artery stent placement. Using data from 947 patients with a history of hypertension or chronic kidney disease from the largest randomized trial of renal artery stent placement, the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) study, we performed exploratory analyses to determine if subsets of patients experienced better outcomes after stent placement than the overall cohort. We examined baseline stenosis severity, systolic blood pressure, and translesion pressure gradient (peak systolic and mean) and performed interaction tests and Cox proportional hazards analyses for the occurrence of the primary endpoint through all follow-up, to examine the effect of these variables on outcomes by treatment group. There were no statistically significant differences in outcomes based on the examined variables nor were there any consistent nonsignificant trends. Based on data from the CORAL randomized trial, there is no evidence of a significant treatment effect of the renal artery stent procedure compared with medical therapy alone based on stenosis severity, level of systolic blood pressure elevation, or according to the magnitude of the trans-stenotic pressure gradient. (Benefits of Medical Therapy Plus Stenting for Renal Atherosclerotic Lesions [CORAL]; NCT00081731).
PURPOSE Adrenal venous sampling (AVS) is a clinically important procedure which is limited by occ... more PURPOSE Adrenal venous sampling (AVS) is a clinically important procedure which is limited by occasional technical failures due to errors in catheter position or sampling. These inadequate samples are often not recognized at the time of the procedure and can lead to non-diagnostic results. Intra-procedural evaluation of cortisol levels obtained from the adrenal and peripheral veins provides confirmation that the samples are adequate prior to leaving the procedure room. We report on our institution’s use of stat cortisol levels to increase the diagnostic yield of AVS in the evaluation of primary hyperaldosteronism (PA). METHOD AND MATERIALS A retrospective review of 46 AVS procedures performed on 43 patients with PA. Stat intra-procedural cortisol levels were available during the 10 most recent patient evaluations within twenty minutes of starting the case. Catheterization was considered successful if the adrenal vein/peripheral vein cortisol ratio for both right and left adrenals at...
Fibromuscular dysplasia (FMD), a non-inflammatory arterial disease, may lead to renovascular hype... more Fibromuscular dysplasia (FMD), a non-inflammatory arterial disease, may lead to renovascular hypertension (HTN) and cerebrovascular disease. Little is known about medication use in FMD. Clinical features and medication use were reviewed in a national FMD registry (12 US sites). Medication usage was assessed in raw and adjusted analyses. Covariates included demographic characteristics, co-morbid conditions and vascular bed involvement. A total of 874 subjects (93.6% female) were included in the analysis. Mean age was 55.6±13.1 years, 74.5% had HTN, 25.4% had a history of transient ischemic attack or stroke, and 7.5% had a history of coronary artery disease (CAD). Renal and cerebrovascular arteries were affected in 70.4% and 74.7%, respectively. Anti-platelet agents were administered to 72.9% of patients. In multivariate analyses, factors associated with a greater likelihood of anti-platelet agent use were older age (OR=1.02 per year, p=0.005), CAD (OR=3.76, p=0.015), cerebrovascular ...
Techniques in vascular and interventional radiology, 2014
Large vessel vasculitis is very uncommon, particularly in Western countries, but can cause seriou... more Large vessel vasculitis is very uncommon, particularly in Western countries, but can cause serious sequelae. Large vessel vasculitis is usually due to either Takayasu arteritis or giant cell arteritis. The available laboratory tests are nonspecific, so the diagnosis is often dependent on imaging findings. The location and pattern of vessel narrowing will usually define the type of vasculitis. Symptomatic vascular stenoses and occlusions can frequently be managed using balloon angioplasty. Familiarity with the indications for treatment and techniques and outcomes associated with angioplasty and surgical alternatives is essential when treating these rare disorders.
Vascular complications after pancreatic transplantation carry a high rate of graft loss. Endovasc... more Vascular complications after pancreatic transplantation carry a high rate of graft loss. Endovascular management of these complications is confined to stent placement for iliac artery inflow disease and embolization for arteriovenous fistulae (AVFs), pseudoaneurysms, or active bleeding. The current study describes the endovascular management of pancreatic transplant venous thrombosis (N = 1), arterial stenosis (N = 5), thrombosis (N = 3), pseudoaneurysms (N = 1), and AVF (N = 2). In addition, embolization of nonfunctioning grafts is described as an endovascular alternative to pancreatectomy.
Mechanical thrombectomy devices are increasingly being used in selected patients with acute venou... more Mechanical thrombectomy devices are increasingly being used in selected patients with acute venous thromboembolic disease to rapidly decrease thrombus burden and establish venous patency. Hemolysis and hemoglobinuria secondary to red blood cell fragmentation is known to occur after the use of these devices. In this article we describe a case in which a 16-year-old female patient developed acute renal failure after use of a mechanical thrombectomy device for treatment of symptomatic iliocaval venous thrombosis.
The three randomized trials of stenting vs medical therapy published so far are so seriously flaw... more The three randomized trials of stenting vs medical therapy published so far are so seriously flawed that it is impossible to make treatment decisions based on their results.
Renal artery fibromuscular dysplasia (FMD) may be underdiagnosed. We evaluated the prevalence of ... more Renal artery fibromuscular dysplasia (FMD) may be underdiagnosed. We evaluated the prevalence of FMD in CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) renal artery stent trial participants, in which FMD was an exclusion criterion for inclusion. We also evaluated the prevalence of FMD in a relatively healthy population of patients undergoing computed tomographic angiographic (CTA) screening for renal donor evaluation. All renal donor CTAs performed at our institution from January 2003 through November 2011 were retrospectively reviewed for the presence of FMD along with patient sex and age. These results were compared to angiographic core lab (ACL) findings for the CORAL trial. The CORAL ACL database contained 997 patients (mean age 69.3 years; 50% female). Fifty-eight (5.8%) CORAL trial patients (mean age 71.8 years; 75.9% female) demonstrated incidental FMD. The renal donor cohort included 220 patients (mean age 40.5 years; 64.5% female). Five (2.3%) demonstrated ...
Journal of the American College of Radiology, 2014
Given the changing climate of health care and the imperative to add value, radiologists must join... more Given the changing climate of health care and the imperative to add value, radiologists must join forces with the rest of medicine to deliver better patient care in a more cost-effective, evidence-based manner. For several decades, interventional radiology has added value to the health care system through innovation and the provision of alternative and effective minimally invasive treatments, which have decreased morbidity, mortality, and overall cost. The clinical practice of interventional radiology embodies many of the features of Imaging 3.0, the program recently launched by the ACR. We provide a review of some of the major contributions made by interventional radiology and offer general principles from that experience, which are applicable to all radiologists.
Journal of vascular and interventional radiology : JVIR, 2017
To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patient... more To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patients who have undergone thoracic stent-graft placement for type B aortic dissection. The study included 62 patients (45 male, 17 female) aged 26-80 years (mean age, 58.1 y) who underwent thoracic endovascular aortic repair for type B aortic dissection at a single institution between January 2005 and May 2015. Mean age of aortic dissections was 5.3 months (range, 0.1-73.3 mo). Maximum aortic diameter at presentation was 41.7 mm ± 8.3. The follow-up period ranged from 3 to 104 months (mean, 27.1 mo). Computed tomographic (CT) angiography studies were reviewed to identify FL diameter enlargements > 5 mm at different levels along and distal to the stent graft. Imaging findings and clinical variables were investigated to determine their correlation with FL enlargement. No significant difference was found between the ages of aortic dissections in patients with and without FL enlargement (P = ....
Randomized clinical trials have not shown an additional clinical benefit of renal artery stent pl... more Randomized clinical trials have not shown an additional clinical benefit of renal artery stent placement over optimal medical therapy alone. However, studies of renal artery stent placement have not examined the relationship of albuminuria and treatment group outcomes. The CORAL study (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) is a prospective clinical trial of 947 participants with atherosclerotic renal artery stenosis randomized to optimal medical therapy with or without renal artery stent which showed no treatment differences (3(5.8% and 35.1% event rate at mean 43-month follow-up). In a post hoc analysis, the study population was stratified by the median baseline urine albumin/creatinine ratio (n=826) and analyzed for the 5-year incidence of the primary end point (myocardial infarction, hospitalization for congestive heart failure, stroke, renal replacement therapy, progressive renal insufficiency, or cardiovascular disease- or kidney disease-related death), for ...
We report our experience with Guenter Tulip filter placement indications, retrievals, and procedu... more We report our experience with Guenter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Guenter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Guenter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.
Journal of the American College of Cardiology, 2015
Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy w... more Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy with medical therapy alone have not shown any benefit of stent placement. However, debate continues whether patients with extreme pressure gradients, stenosis severity, or baseline blood pressure benefit from stent revascularization. The study sought to test the hypothesis that pressure gradients, stenosis severity, and/or baseline blood pressure affects outcomes after renal artery stent placement. Using data from 947 patients with a history of hypertension or chronic kidney disease from the largest randomized trial of renal artery stent placement, the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) study, we performed exploratory analyses to determine if subsets of patients experienced better outcomes after stent placement than the overall cohort. We examined baseline stenosis severity, systolic blood pressure, and translesion pressure gradient (peak systolic and mean) and performed interaction tests and Cox proportional hazards analyses for the occurrence of the primary endpoint through all follow-up, to examine the effect of these variables on outcomes by treatment group. There were no statistically significant differences in outcomes based on the examined variables nor were there any consistent nonsignificant trends. Based on data from the CORAL randomized trial, there is no evidence of a significant treatment effect of the renal artery stent procedure compared with medical therapy alone based on stenosis severity, level of systolic blood pressure elevation, or according to the magnitude of the trans-stenotic pressure gradient. (Benefits of Medical Therapy Plus Stenting for Renal Atherosclerotic Lesions [CORAL]; NCT00081731).
PURPOSE Adrenal venous sampling (AVS) is a clinically important procedure which is limited by occ... more PURPOSE Adrenal venous sampling (AVS) is a clinically important procedure which is limited by occasional technical failures due to errors in catheter position or sampling. These inadequate samples are often not recognized at the time of the procedure and can lead to non-diagnostic results. Intra-procedural evaluation of cortisol levels obtained from the adrenal and peripheral veins provides confirmation that the samples are adequate prior to leaving the procedure room. We report on our institution’s use of stat cortisol levels to increase the diagnostic yield of AVS in the evaluation of primary hyperaldosteronism (PA). METHOD AND MATERIALS A retrospective review of 46 AVS procedures performed on 43 patients with PA. Stat intra-procedural cortisol levels were available during the 10 most recent patient evaluations within twenty minutes of starting the case. Catheterization was considered successful if the adrenal vein/peripheral vein cortisol ratio for both right and left adrenals at...
Fibromuscular dysplasia (FMD), a non-inflammatory arterial disease, may lead to renovascular hype... more Fibromuscular dysplasia (FMD), a non-inflammatory arterial disease, may lead to renovascular hypertension (HTN) and cerebrovascular disease. Little is known about medication use in FMD. Clinical features and medication use were reviewed in a national FMD registry (12 US sites). Medication usage was assessed in raw and adjusted analyses. Covariates included demographic characteristics, co-morbid conditions and vascular bed involvement. A total of 874 subjects (93.6% female) were included in the analysis. Mean age was 55.6±13.1 years, 74.5% had HTN, 25.4% had a history of transient ischemic attack or stroke, and 7.5% had a history of coronary artery disease (CAD). Renal and cerebrovascular arteries were affected in 70.4% and 74.7%, respectively. Anti-platelet agents were administered to 72.9% of patients. In multivariate analyses, factors associated with a greater likelihood of anti-platelet agent use were older age (OR=1.02 per year, p=0.005), CAD (OR=3.76, p=0.015), cerebrovascular ...
Techniques in vascular and interventional radiology, 2014
Large vessel vasculitis is very uncommon, particularly in Western countries, but can cause seriou... more Large vessel vasculitis is very uncommon, particularly in Western countries, but can cause serious sequelae. Large vessel vasculitis is usually due to either Takayasu arteritis or giant cell arteritis. The available laboratory tests are nonspecific, so the diagnosis is often dependent on imaging findings. The location and pattern of vessel narrowing will usually define the type of vasculitis. Symptomatic vascular stenoses and occlusions can frequently be managed using balloon angioplasty. Familiarity with the indications for treatment and techniques and outcomes associated with angioplasty and surgical alternatives is essential when treating these rare disorders.
Vascular complications after pancreatic transplantation carry a high rate of graft loss. Endovasc... more Vascular complications after pancreatic transplantation carry a high rate of graft loss. Endovascular management of these complications is confined to stent placement for iliac artery inflow disease and embolization for arteriovenous fistulae (AVFs), pseudoaneurysms, or active bleeding. The current study describes the endovascular management of pancreatic transplant venous thrombosis (N = 1), arterial stenosis (N = 5), thrombosis (N = 3), pseudoaneurysms (N = 1), and AVF (N = 2). In addition, embolization of nonfunctioning grafts is described as an endovascular alternative to pancreatectomy.
Mechanical thrombectomy devices are increasingly being used in selected patients with acute venou... more Mechanical thrombectomy devices are increasingly being used in selected patients with acute venous thromboembolic disease to rapidly decrease thrombus burden and establish venous patency. Hemolysis and hemoglobinuria secondary to red blood cell fragmentation is known to occur after the use of these devices. In this article we describe a case in which a 16-year-old female patient developed acute renal failure after use of a mechanical thrombectomy device for treatment of symptomatic iliocaval venous thrombosis.
The three randomized trials of stenting vs medical therapy published so far are so seriously flaw... more The three randomized trials of stenting vs medical therapy published so far are so seriously flawed that it is impossible to make treatment decisions based on their results.
Renal artery fibromuscular dysplasia (FMD) may be underdiagnosed. We evaluated the prevalence of ... more Renal artery fibromuscular dysplasia (FMD) may be underdiagnosed. We evaluated the prevalence of FMD in CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) renal artery stent trial participants, in which FMD was an exclusion criterion for inclusion. We also evaluated the prevalence of FMD in a relatively healthy population of patients undergoing computed tomographic angiographic (CTA) screening for renal donor evaluation. All renal donor CTAs performed at our institution from January 2003 through November 2011 were retrospectively reviewed for the presence of FMD along with patient sex and age. These results were compared to angiographic core lab (ACL) findings for the CORAL trial. The CORAL ACL database contained 997 patients (mean age 69.3 years; 50% female). Fifty-eight (5.8%) CORAL trial patients (mean age 71.8 years; 75.9% female) demonstrated incidental FMD. The renal donor cohort included 220 patients (mean age 40.5 years; 64.5% female). Five (2.3%) demonstrated ...
Journal of the American College of Radiology, 2014
Given the changing climate of health care and the imperative to add value, radiologists must join... more Given the changing climate of health care and the imperative to add value, radiologists must join forces with the rest of medicine to deliver better patient care in a more cost-effective, evidence-based manner. For several decades, interventional radiology has added value to the health care system through innovation and the provision of alternative and effective minimally invasive treatments, which have decreased morbidity, mortality, and overall cost. The clinical practice of interventional radiology embodies many of the features of Imaging 3.0, the program recently launched by the ACR. We provide a review of some of the major contributions made by interventional radiology and offer general principles from that experience, which are applicable to all radiologists.
Uploads
Papers by Alan Matsumoto