Papers by Constantino Pena
Vascular and endovascular surgery, 2017
To evaluate the impact of a new angiographic imaging technology on radiation dose during visceral... more To evaluate the impact of a new angiographic imaging technology on radiation dose during visceral embolization procedures involving both fluoroscopy and digital subtraction angiography. A retrospective analysis from a single-center consecutive series of patients was performed comparing 2 angiographic imaging systems. The AlluraClarity (CIQ; Philips Healthcare, Best, the Netherlands) was used in 100 patients (n = 59 male, mean age: 70.6 years) from July 2013 to April 2014 and compared to the former AlluraXper (AX) technology used in 139 patients (n = 71 male, mean age: 70.1 years) from May 2011 to June 2013. Patients were categorized according to body mass index (BMI [kg/m(2)])-group 1: BMI <25, group 2: BMI ≥25 and <30, and group 3: BMI ≥30. Fluoroscopy time, the total dose of iodinated contrast administered, and procedural AirKerma (Ka, r [mGy]) were obtained. Mean BMI was 26.4 ± 5.0 kg/m(2) in the CIQ and 26.4 ± 7.1 kg/m(2) in the AX group ( P = .93). Fluoroscopy time and th...
European Journal of Vascular and Endovascular Surgery, 2003
Objective. To present the results of the endovascular treatment of popliteal artery aneurysms. Me... more Objective. To present the results of the endovascular treatment of popliteal artery aneurysms. Methods. From April 1999 to January 2002, 11 patients, aged 40-94 years, with 12 popliteal aneurysms were treated. Nine (75%) underwent an endoluminal repair, of whom three were done emergently due to a aneurysm rupture. Aneurysm diameter was 28-105 (mean 69) mm. A Hemobahn stent graft was inserted in six, Wallgraft in two and Passager in one case. Results. During a mean follow-up of 14 (3-31) months, four (44%) thromboses occurred: two in the early postoperative period (30 days) and two during the late postoperative period. Two of the four occluded grafts were successfully reopened, and in the one a stenosis of the distal end of the stent graft was treated with balloon dilatation. Patency rates at 1 and 12 months were 64/47% (primary patency) and 88/75% (secondary patency), respectively. Conclusion. Initial experience with endovascular treatment of the popliteal aneurysm in high-risk patients yielded modest results. Larger number of patients and further follow-up time is necessary to evaluate the long-term results.
Journal of Vascular and Interventional Radiology, 2016
To determine whether statin therapy is associated with reduced restenosis following nitinol stent... more To determine whether statin therapy is associated with reduced restenosis following nitinol stent implantation for de novo femoropopliteal artery disease. A total of 135 limbs in 135 patients (mean age, 72 y) implanted with nitinol stents in femoropopliteal occlusions were analyzed (statin arm, n = 91; nonstatin arm, n = 44). The patients were treated with one type of nitinol stent. At baseline, lesions and procedural characteristics were comparable between groups, except that the statin group had more hypertension, coronary artery disease, and hyperlipidemia. There were significant differences in the incidence of binary restenosis between groups at 1 year (45.5% for nonstatin group vs 28.6% for statin group; P = .05) and 2 years (56.8% for nonstatin group vs 38.5% for statin group; P = .04). Primary patency rates at 1 year were 50.5% in the nonstatin group and 72.5% in the statin group (P = .01). Two-year target lesion revascularization rates were 54.5% in the nonstatin group and 35.2% in the statin group (P = .03). On univariate analysis, statin therapy was associated with decreased relative risk of binary restenosis at 1 year (odds ratio [OR], 0.480; 95% confidence interval [CI], 0.227-1.014; P = .050). On multivariate analysis, statin therapy did not significantly affect the odds of binary restenosis (OR, 0.415; 95% CI, 0.071-2.437; P = .330). The incidence of binary restenosis was significantly lower in the statin group than in the nonstatin group following nitinol stent implantation for de novo femoropopliteal artery disease.
Techniques in Vascular and Interventional Radiology, 2014
The unique anatomical location and particular biomechanical factors affecting the popliteal arter... more The unique anatomical location and particular biomechanical factors affecting the popliteal artery provide a challenge to determine the proper endovascular, surgical, or combined intervention for patients with critical limb ischemia who often require prompt management in the presence of severe lifestyle-limiting symptoms or of the risk of limb loss or both. Herein, we provide an overview and practical guide for endovascular management of popliteal artery disease in the setting of critical limb ischemia.
Seminars in Interventional Radiology, 2009
Available and improved options for the treatment of femoral-popliteal disease have increased over... more Available and improved options for the treatment of femoral-popliteal disease have increased over the last decade. Even though most patients suffering from claudication due to femoral-popliteal disease are treated with aggressive medical and noninvasive methods, patients with limb-threatening disease and severely lifestyle-limiting symptoms are treated with invasive treatments, which include endovascular treatment options. Unfortunately, the unique forces involved in this vascular segment have challenged the long-term patency and clinical effectiveness of these treatments. The purpose of this brief review is to discuss treatment strategies and options for patients with femoral-popliteal disease. Included in this discussion will be the review of data from recent published studies and late-breaking trials as it pertains to certain treatment strategies.
Journal of Vascular and Interventional Radiology, 2015
To compare the closure of ≤ 8-F versus 9-F to 12-F femoral access using the 8-F Angio-Seal VIP de... more To compare the closure of ≤ 8-F versus 9-F to 12-F femoral access using the 8-F Angio-Seal VIP device (St. Jude Medical, Inc, St. Paul, Minnesota). In this investigator-initiated, retrospective analysis, a consecutive series of 137 patients (n = 92 male patients [67.2%]; overall mean age, 71.0 y ± 9.8) was evaluated. Common femoral artery access was performed in all patients, and either unfractionated heparin or bivalirudin was used for anticoagulation. Access site complications were defined as follows: type 0, no bleeding; type 1, no actionable bleeding; type 2, actionable bleeding. The 8-F Angio-Seal VIP device was used for closure of ≤ 8-F femoral access in 76 patients (55.5%) and for 9-F to 12-F femoral access in 61 patients (44.5%). Access site complications were observed after 8-F Angio-Seal deployment in 11 patients (8.0%) (≤ 8 F, n = 5 [6.6%]; 9-12 F, n = 6 [9.8%]; P = .54). Comparing ≤ 8-F with 9-F to 12-F femoral access, type 1 complications were observed in 3 and 6 patients (P = .19) and type 2 complications were observed in 2 and 0 patients (P = .50), respectively. All type 1 complications were managed by applying external compression. Type 2 complications (n = 2 pseudoaneurysms) were treated with thrombin injection in 1 patient and secondary percutaneous intervention in 1 patient. Use of the 8-F Angio-Seal for the closure of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 8-F femoral access is safe and effective. Complication rates when using the 8-F Angio-Seal for closure of ≤ 8-F and 9-F to 12-F femoral access are comparable.
Journal of Vascular and Interventional Radiology, 2015
To evaluate reliability, accuracy, and agreement of simple visual estimation (SVE) in determining... more To evaluate reliability, accuracy, and agreement of simple visual estimation (SVE) in determining the degree of peripheral arterial stenosis compared with calibrated measurements. In two sessions, 23 interventionists with a wide range of experience and subspecialty training reviewed 42 angiographic images of lower extremity and carotid arteries (21 iliofemoral arteries and 21 carotid arteries). An independent physician measured all lesions using manual calipers. Intrarater and interrater reliability were assessed by intraclass correlation. A ± 5% error was considered the threshold for accuracy, and weighted κ statistics were computed to assess agreement with respect to the degree of stenosis (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 50%, nonsignificant; 50%-80%, significant; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 80%, severe). Intrarater reliability of SVE was 0.99, and interrater reliability was 0.83. Accuracy varied from 52.8% for images of severe stenosis to 26.5% and 18.1% for significant and nonsignificant stenosis, respectively (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Agreement between SVE and caliper with regard to degree of stenosis was good (weighted κ 0.56) overall with correct classification ranging from 92.6% for severe stenosis to 53.4% and 68.2% for significant and nonsignificant stenosis, respectively (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Misclassification of nonsignificant and significant stenosis was more frequent for carotid arteries than for lower extremities. Despite high reliability, SVE of peripheral arterial stenosis has limited accuracy in determining the exact degree of stenosis. Although severe stenosis is readily identified by SVE, arterial stenosis of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 80% is frequently overestimated, especially for carotid arteries, and should be confirmed by caliper assessment.
Radiology, 1997
To evaluate the use of attenuation measurements from early delayed computed tomographic (CT) scan... more To evaluate the use of attenuation measurements from early delayed computed tomographic (CT) scans to differentiate benign from malignant lesions of the adrenal glands. Forty-four patients (19 men, 25 women; age range, 21-88 years; mean age, 63 years) with 46 adrenal masses underwent dynamic contrast material-enhanced CT and early delayed CT (range, 12-18 minutes; mean delay, 14 minutes) with similar scanning parameters. Each patient also underwent non-contrast-enhanced CT within 3 months of the contrast-enhanced examination. Attenuation of adrenal masses on each type of scan was measured, and receiver operating characteristic analysis was performed. An attenuation threshold of 24 HU was selected; thus, all lesions with attenuation values of 24 HU or less were considered benign. When this threshold was applied to the results, the sensitivity of characterization of adrenal masses on early delayed scans was 96%, and the specificity was 96%. Adrenal masses detected with contrast-enhanc...
CardioVascular and Interventional Radiology, 2015
The purpose of this study is to evaluate a new device providing real-time monitoring on radiation... more The purpose of this study is to evaluate a new device providing real-time monitoring on radiation exposure during fluoroscopy procedures intending to reduce radiation in an interventional radiology setting. In one interventional suite, a new system providing a real-time radiation dose display and five individual wireless dosimeters were installed. The five dosimeters were worn by the attending, fellow, nurse, technician, and anesthesiologist for every procedure taking place in that suite. During the first 6-week interval the dose display was off (closed phase) and activated thereafter, for a 6-week learning phase (learning phase) and a 10-week open phase (open phase). During these phases, the staff dose and the individual dose for each procedure were recorded from the wireless dosimeter and correlated with the fluoroscopy time. Further subanalysis for dose exposure included diagnostic versus interventional as well as short (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10 min) versus long (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10 min) procedures. A total of 252 procedures were performed (n = 88 closed phase, n = 50 learning phase, n = 114 open phase). The overall mean staff dose per fluoroscopic minute was 42.79 versus 19.81 µSv/min (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) comparing the closed and open phase. Thereby, anesthesiologists were the only individuals attaining a significant dose reduction during open phase 16.9 versus 8.86 µSv/min (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Furthermore, a significant reduction of total staff dose was observed for short 51 % and interventional procedures 45 % (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05, for both). A real-time qualitative display of radiation exposure may reduce team radiation dose. The process may take a few weeks during the learning phase but appears sustained, thereafter.
Techniques in Vascular and Interventional Radiology, 2014
Critical limb ischemia (CLI) is exhibited in patients with symptoms of severe claudication (rest ... more Critical limb ischemia (CLI) is exhibited in patients with symptoms of severe claudication (rest pain) and ischemic tissue loss and gangrene. Magnetic resonance angiography and computed tomography angiography have risen to the forefront of vascular imaging over the last 2 decades. Both modalities have been shown to compare favorably with digital subtraction angiography in guiding the clinical management of patients with CLI. Understanding the advantages and limitations of both modalities allows for the proper selection of the best examination for a particular patient with CLI. Ultimately, the enhanced understanding of the vascular anatomy by obtaining noninvasive imaging should make subsequent revascularization safer and more effective.
Techniques in Vascular and Interventional Radiology, 2010
Vascular disease involving the superficial femoral artery (SFA) is common. Once the decision to t... more Vascular disease involving the superficial femoral artery (SFA) is common. Once the decision to treat the SFA is made, the benefits and limitations of angioplasty and stents must be applied to each specific patient. Additionally, the potential role of covered stents as well as drug eluting stents must be considered.
Korean Journal of Radiology, 2001
Objective: To investigate the efficacy of gadobenate dimeglumine (Gd-BOPTA) enhanced MR imaging f... more Objective: To investigate the efficacy of gadobenate dimeglumine (Gd-BOPTA) enhanced MR imaging for the detection of liver lesions in patients with primary malignant hepatic neoplasms.
Techniques in Vascular and Interventional Radiology, 2006
The discovery of heparin and its eventual incorporation into many therapeutic and diagnostic proc... more The discovery of heparin and its eventual incorporation into many therapeutic and diagnostic procedures has made this agent ubiquitous in the fields of cardiac and vascular medicine. Heparin however does have a significant complication and side-effect profile that includes both bleeding as well as vessel thrombosis through the development of heparin-induced thrombocytopenia. The recent addition of direct thrombin inhibitors, for example, bivalirudin, to the anticoagulation armaterium has produced favorable outcomes. Most of the experience with bivalirudin has been in coronary interventions and only recently have more interventionalists been turning to this agent as the sole anticoagulant for peripheral interventions even in patients who could tolerate heparin. In this review, we describe our experience with bivalirudin in peripheral interventions emphasizing how we dose and monitor this drug. In addition, this article discusses the findings in existing clinical trials involving bivalirudin.
Techniques in Vascular and Interventional Radiology, 2014
ABSTRACT Buerger disease is a nonatherosclerotic vasculitis that is triggered by substantial expo... more ABSTRACT Buerger disease is a nonatherosclerotic vasculitis that is triggered by substantial exposure to tobacco. This disease usually affects small- and medium-sized arteries in the upper and lower extremities. All clinicians who take care of patients with peripheral arterial disease should know the clinical features and diagnostic evaluation of Buerger disease. In this article, we review the clinical presentation and diagnostic criteria for Buerger disease. We describe the diagnostic work-up of patients suspected of having Buerger disease and discuss the typical findings on noninvasive arterial studies and angiography. Lastly, we review the management of these patients, including medical therapy, with an emphasis on smoking cessation, as well as the potential role of revascularization, both surgical and endovascular. Copyright © 2014 Elsevier Inc. All rights reserved.
Vascular Medicine, 2011
Page 1. Vascular Medicine 16(4) 314 –316 © The Author(s) 2011 Reprints and permission: sagepub. c... more Page 1. Vascular Medicine 16(4) 314 –316 © The Author(s) 2011 Reprints and permission: sagepub. co.uk/journalsPermissions.nav DOI: 10.1177/1358863X11406959 vmj.sagepub.com We present a case of severe aortic coarctation ...
Radiology, 2008
To determine the effectiveness of percutaneous balloon dilation of benign postoperative biliary s... more To determine the effectiveness of percutaneous balloon dilation of benign postoperative biliary strictures. We received approval from our institutional review board to undertake this retrospective HIPAA-compliant study, and informed consent was waived. From April 1, 1977, to April 1, 2007, percutaneous biliary balloon dilation (PBBD) was performed in 85 patients with benign biliary strictures. In the 75 patients with follow-up (31 male, 44 female; mean age, 56 years; mean follow-up, 8 years), 205 PBBD procedures were performed during 112 treatments of 84 biliary strictures. PBBD of the stricture was performed with a noncompliant balloon (8-12-mm diameter). PBBD procedures were repeated at 2- to 14-day intervals until cholangiography demonstrated free drainage of contrast material to the bowel and no residual stenosis. An internal-external biliary drain was left in situ for a mean of 14-22 days and removed after a clinical trial of catheter clamping and a normal cholangiogram. All procedures were technically successful, and 52, 11, 10, and two patients underwent a total of one, two, three, and four PBBD treatments, respectively. Four of 205 procedures (2%) led to major complications: two subphrenic abscesses, one hepatic arterial pseudoaneurysm, and one case of hematobilia treated with transfusion. Six patients died from unrelated causes and three from hepatitis C-related liver failure. The probability of a patient not developing clinically significant restenosis at 5, 10, 15, 20, and 25 years was 0.52, 0.49, 0.49, 0.41, and 0.41, respectively, after the first PBBD treatment and 0.43, 0.30, 0.20, 0.20, and 0.20, respectively, after the second PBBD treatment. No significant difference was found in the rate of clinically significant restenosis after the first PBBD between strictures at anastomotic and nonanastomotic sites (P = .75). During the follow-up period, 56 of 75 patients (75%) had successful management with PBBD. PBBD of benign strictures demonstrates long-term effectiveness. No significant difference was found in the rate of clinically significant restenosis after PBBD of biliary strictures at anastomotic and nonanastomotic sites.
Radiology, 2013
To test whether newer bilayer barium sulfate-bismuth oxide composite (XPF) thyroid collars (TCs) ... more To test whether newer bilayer barium sulfate-bismuth oxide composite (XPF) thyroid collars (TCs) provide superior radiation protection and comfort during fluoroscopy-guided interventions compared with standard 0.5-mm lead-equivalent TCs. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study, and 144 fluoroscopy-guided vascular interventions were included at one center between October 2011 and July 2012, with up to two operators randomly assigned to wear XPF (n = 135) or standard 0.5-mm lead-equivalent (n = 121) TCs. Radiation doses were measured by using dosimeters placed outside and underneath the TCs. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100, with 100 indicating optimal comfort). Adjusted differences in comfort and radiation dose reductions were calculated by using a mixed logistic regression model and the common method of inverse variance weighting, respectively. Patient (height, weight, and body mass index) and procedure (type and duration of intervention, operator, fluoroscopy time, dose-area product, and air kerma) data did not differ between the XPF and standard groups. Comfort was assessed in all 256 measurements. On average, the XPF TCs were 47.6% lighter than the standard TCs (mean weight ± standard deviation, 133 g ± 14 vs 254 g ± 44; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) and had a significantly higher likelihood of a high level of comfort (visual analog scale &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;90; odds ratio, 7.6; 95% confidence interval: 3.0, 19.2; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Radiation dose reduction provided by the TCs was analyzed in 117 data sets (60 in the XPF group, 57 in the standard group). The mean radiation dose reductions (ie, radiation protection) provided by XPF and standard TCs were 90.7% and 72.4%, with an adjusted mean difference of 17.9% (95% confidence interval: 7.7%, 28.1%; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) favoring XPF. XPF TCs are a lightweight alternative to standard 0.5-mm lead-equivalent TCs and provide superior radiation protection during fluoroscopy-guided interventions.
Radiology, 2000
To determine whether computed tomographic (CT) scans and attenuation measurements on contrast mat... more To determine whether computed tomographic (CT) scans and attenuation measurements on contrast material-enhanced and nonenhanced CT scans could be used to characterize adrenal masses, in particular, to characterize these lesions by using adrenal washout characteristics at contrast-enhanced CT. Eighty-six patients (49 men, 37 women; age range, 29-86 years; mean age, 72 years) with 101 adrenal lesions depicted at contrast-enhanced CT underwent delayed (mean, 9 minutes) enhanced scanning. Seventy-eight patients also underwent nonenhanced CT. Mean diameter of the benign lesions was 2.1 cm (range, 1.0-4.2 cm); mean diameter of the malignant lesions was 2.3 cm (range, 1.0-4.1 cm). Region-of-interest measurements were obtained at nonenhanced, dynamic enhanced, and delayed enhanced CT and were used to calculate a relative percentage washout as follows: 1 - (Hounsfield unit measurement on delayed image / Hounsfield unit measurement on dynamic image) x 100%. Ninety-nine of 101 lesions were correctly characterized as benign or malignant with a relative percentage washout threshold of 50% on delayed scans; benign lesions demonstrated more than 50% washout; and malignant lesions, less than 50% washout. Two benign lesions demonstrating less than 50% washout were characterized as benign by using conventional CT. Calculation of relative percentage washout on dynamic and delayed enhanced CT scans may lead to a highly specific test for adrenal lesion characterization, reduce the need for, and possibly obviate, follow-up imaging or biopsy.
Minimally Invasive Therapy & Allied Technologies, 1999
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Papers by Constantino Pena