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Anthony J Comerota

Publications and source records attributed to Anthony J Comerota.

At least 19 recordsLinked to original sources
PubMed2006

Technique of contemporary iliofemoral and infrainguinal venous thrombectomy.

Patients with acute deep vein thrombosis involving the iliofemoral venous system experience the most severe postthrombotic sequelae. Treatment designed to reduce or eliminate the postthrombotic syndrome must necessarily remove thrombus to eliminate obstruction. Unfortunately, currently published guidelines do not recommend venous thrombectomy and actually recommend against its use because of the poor results initially reported. However, recent reports of venous thrombectomy and the long-term results of a large randomized trial confirm the significant benefit compared with anticoagulation alone. The technique of contemporary venous thrombectomy follows basic vascular surgical principles and offers patients the opportunity for complete or nearly complete thrombus extraction, thereby avoiding the significant morbidity of their anticipated postthrombotic syndrome. The techniques described herein represent the authors' approach to patients with few alternatives to clear the venous system. Because the patient benefit is well established, vascular surgeons should include contemporary venous thrombectomy as part of their routine operative armamentarium, offering this procedure to patients with extensive deep vein thrombosis involving the iliofemoral venous system, especially if other options are not available or have failed.

Femoral Vein↗
PubMed2006

Retrievable IVC filters: a decision matrix for appropriate utilization.

The use of vena caval filters for patients at high risk for or with venous thromboembolism has increased substantially during the past two decades. Advances in technology have improved the ease of insertion, increasing physicians' acceptance of the procedure. Until recently, all vena caval filters available in the United States were considered permanent, but since 2003, three nonpermanent-or retrievable-filters have been approved by the Food and Drug Administration. This article reviews the indications for caval filtration in patients at risk for venous thromboembolic events. A decision matrix is suggested for use of retrievable (optional) vena caval filters.

Decision Making↗
PubMed2006

Effect of antiplatelet agents clopidogrel, aspirin, and cilostazol on circulating tissue factor procoagulant activity in patients with peripheral arterial disease.

Tissue factor (TF) is the physiological initiating mechanism for blood coagulation. Platelets play an important role in monocyte TF expression, thrombosis and inflammation. Aspirin, clopidogrel and cilostazol, which inhibit platelet responses by different mechanisms, are widely used in patients with arterial diseases. We tested the hypothesis that platelet-inhibiting agents inhibit the levels of circulating TF procoagulant activity (TF-PCA) in patients with peripheral arterial disease (PAD). Twenty-six patients with lower extremity PAD, average age 65.9 +/- 8.4 years (mean +/- SEM), were studied at baseline and following sequential two-week treatment regimens with aspirin (325 mg daily), clopidogrel (75 mg daily) or a phosphodiesterase inhibitor cilostazol (100 mg twice daily) singly, and with each possible combination of these agents. Circulating TF-PCA in whole blood, and plasma factor VIIa, prothrombin fragment F1.2, thrombin-antithrombin complexes (TAT), and P-selectin were measured. Baseline TF-PCA levels in the patients were elevated (131 +/- 19 U/ml) compared to control subjects (23 +/- 2, p < 0.0001). TF-PCA levels declined following treatment with clopidogrel alone, and with combinations of clopidogrel with aspirin or cilostazol, with the lowest levels being with the triple-drug combination. Plasma P-selectin declined in all treatment groups. No changes were noted in plasma factor VIIa, F1.2 or TAT. In conclusion, treatment of PAD patients with antiplatelet agents decreases circulating TF, a molecule with prothrombotic and proinflammatory effects. These findings suggest an unrecognized mechanism, beyond inhibiting aggregation responses, for the efficacy of antiplatelet drugs in patients with arterial diseases.

Aged↗
PubMed2005

Effect on platelet function of cilostazol, clopidogrel, and aspirin, each alone or in combination.

Management of peripheral arterial disease (PAD) requires standard atherosclerotic risk management interventions. However, PAD is often complicated by walking pain (intermittent claudication [IC]), which requires symptom-specific therapies as well. Thus, all PAD patients are encouraged to take antiplatelet agents to reduce the associated risks of major cardiovascular events, and those with IC may also require treatment with cilostazol, an agent proven to increase exercise capacity and enhance quality of life in these patients. Although it was initially thought that cilostazol's antiplatelet properties might render it unsafe to use in combination with other platelet inhibitors because of possible additive effects, a recent study has dispelled such concerns. There is evidence that in a crossover trial of 21 patients with PAD and IC, aspirin alone, or clopidogrel alone, significantly increased bleeding times, but cilostazol alone did not. The combination of aspirin and clopidogrel had a greater effect on increasing bleeding time than either monotherapy, and no further bleeding time prolongation was observed, when cilostazol was added to any aspirin/clopidogrel regimen. These findings suggest that PAD patients with IC may be safely managed with both cilostazol and standard antiplatelet therapy, without increasing the risk of adverse bleeding effects.

Aspirin↗
PubMed2005

Suprarenal endograft fixation avoids adverse outcomes associated with aortic neck angulation.

The advent of endovascular therapy has had a profound impact on repair of abdominal aortic aneurysms (AAA). Prudent patient selection, particularly in regard to unfavorable anatomy, is emerging as perhaps the most important determinant of endovascular abdominal aortic aneurysm repair (EVAR) outcome. The aim of this study was to examine the association of one such anatomic factor, proximal aortic neck angulation, with the incidence of adverse events following EVAR. Prospectively collected data on 289 EVAR repairs with the Talent endograft (Medtronic, Inc., Minneapolis, MN) from March 1998 to June 2000 were analyzed. Stent graft-specific adverse events studied were migration, endoleak, kinking, thrombosis, and AAA expansion. Computed tomography (CT) scanning with three-dimensional post-processing and/or aortography was used to measure aortic neck angle. Patients were categorized into one of four groups according to their neck angle: I (0-10 degrees); II (11-39 degrees); III (40-59 degrees); or IV (60-85 degrees). Outcomes were evaluated by chi-squared analysis and ANOVA. There was a direct correlation between AAA diameter and neck angle (p = 0.002). There was no difference in endoleak rate (p = 0.877), stent migration (p = 0.850), or AAA expansion rate (p = 0.599) between groups. Device kinking >45 degrees was associated with neck angulation > or = 60 degrees (p = 0.013), but not with other adverse outcomes. The average neck angle was 30 degrees in patients with endoleaks and 31 degrees in patients without endoleaks. Increasing aortic neck angulation was not associated with the selected adverse outcomes within 1 year following EVAR with the Talent stent graft using suprarenal fixation with the exception of graft kinking. This may be related to the graft design that permits suprarenal aortic fixatiou of the proximal stent graft, Whether severe degrees of angulation of 60 degrees or greater can be safely treated with suprarenal fixation requires further study.

Aorta, Abdominal↗
PubMed2005

Endovascular stenting to treat chronic long-segment inferior vena cava occlusion.

Chronic inferior vena cava (IVC) occlusion is often associated with debilitating symptoms. Supportive therapy is the treatment offered to most patients, often with poor symptom control. Patients have had to learn to cope with the sequelae of the syndrome and to accept lifelong disability and pain. This may no longer be the case, because endovascular procedures have emerged as a promising alternative for treatment of chronic IVC occlusion. We present 2 case reports of long-standing long-segment IVC occlusion successfully treated with endovascular procedures that incorporated progressive balloon dilation and stenting. The remarkably rapid relief of pain and swelling and overall improvement in quality of life warrants attempts to correct the condition in other patients with IVC occlusion.

Adult↗
PubMed2005

Carotid endarterectomy in octogenarians: does increased age indicate "high risk?".

OBJECTIVE: Carotid endarterectomy (CEA) is proven to be the most effective treatment for symptomatic carotid artery stenosis of 50% or greater and asymptomatic carotid stenosis of 60% or greater. Although the prevalence of carotid artery disease increases with age, most prospective and randomized trials have excluded patients older than 80 years, implying that they are either at higher procedural risk or have decreased life expectancy. Since advanced age (>/=80 years) has been viewed as a "high-risk" indicator for CEA, age >/=80 years has been used as an indication for alternative treatment. The study was conducted to determine if age >/=80 years is related to increased morbidity, mortality, and length of stay in patients undergoing CEA. METHODS: In the 12-year period from 1993 to 2004, 2217 CEAs were performed in 1961 patients. Three hundred sixty procedures were performed in 334 patients >/=80 years. Demographics, presentation, risk factors, operative outcome, and survival were analyzed. Contemporary literature was reviewed and the results summarized. RESULTS: In patients aged >/=80 years, compared with their younger cohort, there was no difference in stroke (1.1% vs 0.8%, P = .333) but there was a higher operative mortality (1.9% vs 0.8%, P = .053). The combined stroke/death rate was higher in octogenarians (3.1% vs 1.5%, P = .041). This difference was due to the greater stroke/death rate in symptomatic octogenarians vs asymptomatic octogenarians (6.0% vs 0.9%, P = .007). The average postoperative length of stay was 3.2 +/- 4.8 days for octogenarians compared with 2.4 +/- 3.5 days for their younger counterparts ( P < .001). Thirty-seven percent of the octogenarians were discharged on the first postoperative day vs 51% ( P < .001), whereas 13% remained hospitalized beyond 5 days vs 8% ( P = .003). Although Kaplan-Meier survival curves show a higher mortality in octogenarians, survival after CEA approaches that of the overall population. A summary of the contemporary literature of CEA in 2204 patients >/=80 shows an operative stroke rate of 2.23% and death rate of 1.28%, with a combined stroke/death rate of 3.51%. CONCLUSION: CEA is a safe and effective procedure in the octogenarian. The combined stroke/death rate is increased in patients aged >/=80, indicating increased risk, predominantly in symptomatic patients. Although CEA risk in octogenarians is higher compared with a younger cohort, outcomes remain within acceptable national guidelines and within outcome measures known to confer benefit compared with best medical care. Therefore, the term "high risk" should not be arbitrarily applied to patients reaching the 80-year threshold. This is confirmed by the contemporary literature.

Age Factors↗
PubMed2004

Unilateral lower extremity paralysis after coil embolization of an internal iliac artery aneurysm.

Neurologic complications after treatment of internal iliac artery (IIA) aneurysms are rare, especially if confined to one IIA. We report a patient in whom profound right lower extremity paresis developed after unilateral right IIA coil embolization for treatment of a 4-cm IIA aneurysm, despite the presence of a patent contralateral IIA. This case illustrates the important, yet unpredictable, nature of pelvic blood flow to the distal spinal cord and lumbosacral plexus and the unpredictable consequence of IIA occlusion.

Aged↗
PubMed2004

Gender differences in blood velocities across carotid stenoses.

OBJECTIVES: Carotid duplex scanning is the standard test for documenting carotid disease. Carotid endarterectomy effectively reduces stroke in selected patients with carotid artery disease. Data from large national randomized trials suggest that the benefits of CEA may be gender dependent. Because many diagnoses are made and treatment is based on the results of carotid duplex ultrasound scanning alone, it is important to determine whether different diagnostic thresholds should be used in men and women. The purpose of this study was 2-fold: to examine whether there is an overall gender difference in carotid velocity at similar arteriographic stenoses, and to determine whether there are significant differences at clinically relevant thresholds of disease. METHODS: A database of 938 carotid arteriogram entries was established prospectively, with accompanying measurements of peak systolic velocity (PSV) and end-diastolic velocity (EDV). The percent of internal carotid artery stenosis seen on arteriograms was calculated according to criteria from the North American Symptomatic Carotid Endarterectomy Trial. Analyses were made in 536 carotid arteries in men and 402 carotid arteries in women. In addition, the single most diseased artery per patient was analyzed by gender. PSV and EDV were averaged for data subsets according to 10% intervals of internal carotid artery stenoses. Velocity for each interval was compared between men and women with the Student t test. Receiver operator characteristic curves were developed to define optimal duplex criteria for 60% and 70% stenosis. RESULTS: For all intervals, PSV and EDV averaged 9% and 6% higher, respectively, in women than in men. Significant gender differences existed between PSV and EDV for 60% and 70% stenosis (P = .03). When a single vessel per patient was analyzed these observations persisted, but lost significance for PSV at 60% stenosis (P = .18). Receiver operator characteristic curves at 90% sensitivity demonstrated that optimal PSV for 60% stenosis was 160 cm/s and 180 cm/s, and for 70% stenosis was 185 cm/s and 202 cm/s, in male and female patients, respectively. CONCLUSIONS: Women have higher carotid blood flow velocity than men do. Gender differences exist, and are notably different at clinically relevant thresholds for intervention. These data indicate that different criteria should be used for interpreting carotid velocity profiles in women than in men, and have potentially important implications for patient care.

Adult↗
PubMed2004

Ultrasound findings after radiofrequency ablation of the great saphenous vein: descriptive analysis.

OBJECTIVE: As an emerging endovascular alternative to ligation and stripping of the incompetent greater saphenous vein (GSV), radiofrequency ablation was monitored with ultrasound scanning to evaluate anatomic results. Neovascularization and inflammation are potential consequences that lead to the appearance of small vessels. The natural history of the below-knee untreated GSV segment may be important in our understanding of ongoing chronic venous disease. An ultrasound follow-up study was conducted to determine the prevalence of small vessel networks, defined as veins and arteries less than 2 mm in diameter, adjacent to the saphenofemoral junction (SFJ); prevalence of small vessel networks adjacent to the treated GSV in the thigh; and fate of the below-knee untreated GSV distal to the ablated segment. METHODS: One hundred six extremities with radiofrequency ablation of the GSV for treatment of superficial venous insufficiency were followed up with high-resolution ultrasound imaging 4 to 25 months (median, 9 months) after the procedure. Ninety-three limbs had concomitant ligation and division of the SFJ and its tributaries, and 13 limbs underwent radiofrequency ablation without SFJ ligation. Ultrasound was used to evaluate patients for small vessel networks, and concomitant findings of small vessel networks and recanalization at the SFJ and adjacent to the treated GSV. The status of the below-knee segment of untreated GSV was evaluated for patency and reflux. Data analysis compared the findings in the ligation group with those in the no-ligation group, with the chi 2 test and Fisher exact test. RESULTS: We found small vessel networks in 65% (n = 69) of extremities: 15% (n = 16) at the SFJ only, 26% (n = 28) in the thigh only, and 24% (n = 25) at both the SFJ and thigh, resulting in a small vessel network prevalence of 39% (n = 41) at the SJF and 50% (n = 53) in the thigh. The prevalence of small vessel networks at the SFJ was significantly less after radiofrequency ablation with SFJ ligation (34%, 32 of 93) than after radiofrequency ablation without ligation (69%, 9 of 13; P = .035). Small vessel networks and GSV recanalization at the SFJ was more common in patients undergoing radiofrequency ablation without ligation (46%, 6 of 13) than after radiofrequency ablation with ligation (14%, 13 of 93; P = .014). The prevalence of small vessel networks in the thigh was not affected by SFJ ligation. The below-knee GSV was patent in 79% (84 of 106), and 58% (61 of 106) demonstrated reflux, a decrease from the pre-radiofrequency ablation rate of 71% (75 of 106), possibly because thrombosis extended distally beyond the ablated segment in 16% (17 of 106) of the legs. CONCLUSIONS: Small vessel networks were detected adjacent to or in connection with most of the radiofrequency ablation-treated GSVs. SFJ ligation was associated with fewer small vessel networks and proximal GSV recanalization. Most below-knee untreated GSV segments remained patent, and most exhibited reflux.

Adult↗
PubMed2004

Aortic diameter is an insensitive measurement of early aneurysm expansion after endografting.

PURPOSE: To determine the sensitivity of various methods of diameter measurement to detect abdominal aortic aneurysm (AAA) size change following endovascular grafting. METHODS: Sixty-eight patients (59 men; mean age 68 years, range 47-84) with 3-dimensional reconstruction of 196 computed tomography (CT) studies (68 preoperative, 128 follow-up) were studied. Implanted devices included 50 bifurcated and 18 straight stent-grafts. All diameter measurements were obtained from reformatted CT slices perpendicular to the center of blood flow. Three diameter measurements were made for each study: (1) transverse (TR), (2) anteroposterior (AP), and (3) maximum diameter in any orientation (Dmax). Volume measurements were calculated from the lowest main renal artery to the aortic bifurcation. Changes in diameter and volume were determined by subtracting follow-up measurements from preop measurements. Diameter and volume changes >5 mm and 10%, respectively, were considered significant. RESULTS: AAA volume significantly increased in 20 (15%) studies, decreased in 84 (66%), and remained unchanged in 24 (19%). Agreement between methods of diameter measurement (TR, AP, Dmax) and volume change were 35%, 15%, and 25% for volume increase >10%, respectively, and 70%, 88%, and 74%, respectively, for volume decrease >10%. The orientation of maximum diameter varied in individual serial exams in 19 (28%) patients. Three of 12 patients with a study showing volume increase failed to demonstrate endoleak. CONCLUSIONS: Diameter measurements were not sensitive in detecting enlarging AAA after endografting. Volume measurement determined by 3D reconstruction is the preferred method for early diagnosis of patients with enlarging AAA that may indicate increased risk of rupture after aortic endografting.

Aged↗
PubMed2004

Post-endograft abdominal aortic aneurysm shrinkage varies among hospitals: observations from multicenter trials.

PURPOSE: To evaluate differences in abdominal aortic aneurysm (AAA) shrinkage among hospitals following protocol-driven patient selection and using endografts from a single manufacturer. METHODS: Standardized inclusion criteria for the Talent endograft multicenter trials included AAA diameter >/=40 mm and proximal neck limits of length >/=5 mm, diameter 14 to 32 mm, and angle </=60 degrees. AAA reporting standards categories were used to classify distal aorta and common iliac artery involvement. Serial computed tomographic scans through 12-month follow-up were examined by independent core laboratory review. Significant shrinkage was defined as a >/=5-mm decrease in the AAA largest minor axis diameter. Trial sites with >10 complete study cases were selected for stepwise logistic regression analysis. In the 13 trial sites meeting this criterion, 323 patients (mean age 74; 93% men) were treated for aneurysms with a mean pretreatment diameter of 53 mm. RESULTS: At 12 months, significant AAA shrinkage occurred in 192 (59%) cases. The AAA shrinkage rate was 71% to 82% at 3 sites, 60% to 64% at 4 sites, 45% to 50% at 4 sites, and 35% and 27% at the 2 remaining sites. In the multivariate analysis, the hospital site showed a strong, independent association with aneurysm shrinkage (p<0.04). Neck and pretreatment AAA diameters were also found to be important factors (p<0.04). Age, gender, AAA classification, neck length, and angle were not significant correlates. Sixty-four (20%) endoleaks (29 type I, 34 type II, and 1 type III) were observed. The incidence of proximal endoleak was significantly different among sites (p<0.001) and highest in the 3 sites with the lowest AAA shrinkage rate. CONCLUSIONS: AAA shrinkage rates vary significantly among hospitals using the same endograft and protocol-defined patient selection criteria. Site-specific factors appear to be an important variable leading to successful endograft repair, as defined by post-endograft aneurysm shrinkage.

Aged↗
PubMed2003

Managing PAD with multiple platelet inhibitors: the effect of combination therapy on bleeding time.

PURPOSE: Patients with lower-extremity peripheral arterial disease (PAD) face a high risk of cardiovascular morbidity and mortality. Platelet inhibition (PI) significantly reduces this risk. Combination PI is common and increasingly indicated in patients with PAD; however, the effect on platelet function has not been objectively evaluated. Aspirin (ASA), clopidogrel (Clop), and cilostazol (Cilo) are the three most commonly used PI drugs in patients with PAD. A prospective, sequential evaluation of platelet function using the template bleeding time (BT) was performed for PAD patients taking these medications singly and in combination. METHODS: Twenty-one patients with PAD, averaging 65.9 years of age, were studied. Patients were placed on sequential two-week regimens of the following therapies: washout (no PI), ASA (325 mg daily), ASA + Cilo (100 mg twice daily), washout, Cilo, Cilo + Clop (75 mg each day), washout, Clop, Clop + ASA, and Clop + ASA + Cilo. At the end of each phase, trained personnel measured the BT. RESULTS: Baseline bleeding time for the group was 4.29 +/- 1.69 minutes. ASA (BT = 6.64 +/- 3.52) and Clop (BT = 10.17 +/- 5.4) significantly prolonged bleeding time (P < 0.01); however, no significant effect was observed with Cilo alone (BT = 5.41 +/- 2.69). Combined treatment with ASA + Clop (BT = 17.39 +/- 4.59) had a more pronounced effect on BT compared with either agent alone (P < 0.01). The addition of Cilo to either ASA (BT = 8.3 +/- 4.27) or Clop (BT = 12.7 +/- 7.46) or the combination of ASA + Clop (BT = 17.92 +/- 4.69) did not prolong BT. CONCLUSION: All patients with PAD require platelet inhibition, and many require pharmacotherapy for intermittent claudication. The platelet inhibitors aspirin and clopidogrel are used for the reduction of ischemic events. They significantly prolong bleeding time individually and to a greater extent in combination. Cilo is used to improve walking distance in patients with intermittent claudication. When Cilo is added to ASA, Clop, or the combination of the two, there is no additional increase in bleeding time. Therefore, Cilo can be used in combination with other platelet inhibitors without an additional effect on platelet function as reflected by the bleeding time.

Aged↗