Search PubMed⌕ Search

Biomedical subjects

Daniel G Clair

Publications and source records attributed to Daniel G Clair.

24 records · Page 2Linked to original sources
PubMed2002

Guidelines for the reporting of renal artery revascularization in clinical trials.

Although the treatment of atherosclerotic renal artery stenosis with use of percutaneous angioplasty, stent placement, and surgical revascularization has gained widespread use, there exist few prospective randomized controlled trials (RCTs) comparing these techniques to each other or against the standard of medical management alone. To facilitate this process as well as help answer many important questions regarding the appropriate application of renal revascularization, well-designed and rigorously conducted trials are needed. These trials must have clearly defined goals and must be sufficiently sized and performed so as to withstand intensive outcomes assessment. Toward this end, this document provides guidelines and definitions for the design, conduct, evaluation, and reporting of renal artery revascularization RCTs. In addition, areas of critically necessary renal artery revascularization investigation are identified. It is hoped that this information will be valuable to the investigator wishing to conduct research in this important area.

Angioplasty, Balloon↗
PubMed2002

Aortic dissection with branch vessel occlusion: percutaneous treatment with fenestration and stenting.

Aortic dissection involves a tear in the intimal and medial layers of the aortic wall. Early surgical treatment of this condition can be fraught with complications especially when the procedure to be performed involves treatment of renal and visceral vessels. Additionally, patients with this problem can have severe compromise of the flow to branches or the entire aortic distribution. Methods of endovascular therapy for these problems limit the surgical stress and often can be performed in less time than surgical revascularization might require. The use of endovascular stenting to improve vessel perfusion and fenestration of the dissection membrane to decrease pressure within the false lumen can be performed to relieve ischemic vascular beds and potentially decrease the risk of aneurysmal dilatation of the aorta. The increasing use of these techniques may allow stabilization of these patients before open repair of more proximal aortic dissection or a combination of therapy with endovascular stent grafting techniques.

Aortic Dissection↗
PubMed2002

A prospective, randomized study of saphenous vein patching versus synthetic patching during carotid endarterectomy.

OBJECTIVE: The objective of this study was the determination of whether the choice of either autogenous saphenous vein (ASV) or synthetic material for patch angioplasty significantly influences the results after carotid endarterectomy (CEA). METHODS: With Institutional Review Board approval, 195 patients (145 men and 50 women; mean age, 69 years) who underwent 207 CEAs were prospectively randomized to arteriotomy closure with ASV or synthetic patches from July 1996 to January 2000. One hundred and one patients (52%) were randomized to the ASV cohort, and 94 (48%) were randomized to the synthetic cohort. Aside from a slight gender imbalance (70% versus 79% male in the ASV versus the synthetic group), there were no clinically important differences in baseline demographic variables, risk factors, or surgical indications between the ASV and synthetic groups. RESULTS: With all 207 randomized procedures on an intent-to-treat basis, there were two early (<30 days) postoperative deaths (1%). There were three perioperative strokes in the ASV cohort (3.0%) and two in the synthetic cohort (2.1%; P =.99). Two of these early strokes occurred in a subset of nine patients who received neither patch material, all after randomization but before CEA. Two patients in each group had late strokes. The cumulative freedom from stroke rate at 1 year (ASV, 94%; synthetic, 95%) was virtually identical for both cohorts. With the 125 patients who had at least one postoperative duplex scan, the incidence rate of recurrent (>or=60%) carotid stenosis was 4.8% (three of 62) for the ASV group and 6.3% (four of 63) for the synthetic group (P =.99). CONCLUSION: No significant differences in the stroke, mortality, or restenosis rates were shown between the ASV and the synthetic cohorts. While conceding the power limitations inherent in this study, we conclude that CEA may be safely performed with similar early results with ASV or synthetic patches.

Aged↗
PubMed2002

Gender as a primary predictor of outcome after carotid endarterectomy.

OBJECTIVE: Post hoc analysis results of the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study suggest that carotid endarterectomy (CEA) may not be as efficacious in women as it is in men. This study was undertaken for the evaluation of whether there is a difference between men and women in early postoperative outcome after CEA and whether such a difference is consistent across other predictors. METHODS: We conducted a retrospective review of all CEAs entered into our departmental registry between January 1, 1989, and November 30, 2000. A total of 3422 CEAs was performed in 3077 consecutive patients. The ratio of men to women was 2:1, and the ratio of patients who were asymptomatic to patients who were symptomatic was 2.3:1. The following in-hospital outcome data were analyzed: transient ischemic attack (TIA), stroke, mortality, combined TIA or stroke, and combined stroke or mortality. Univariate and multivariate analysis results of selected risk factors for an adverse perioperative event were assessed with generalized estimating equation analysis with backwards selection. The following risk factors were considered: gender, preoperative neurologic status, urgency of operation, type of arteriotomy repair, reoperative CEA for recurrent stenosis, history of cardiopulmonary disease, previous coronary artery intervention, simultaneous CEA and coronary bypass grafting surgery, renal failure, and diabetes. RESULTS: Univariate analysis results of gender differences revealed that women were at higher risk for a postoperative TIA or stroke (3.3% for women versus 2.1% for men; odds ratio [OR], 1.6; confidence interval [CI], 1.04 to 2.5; P =.03) and for postoperative stroke or mortality (3.1% for women versus 2.1% for men; OR, 1.6; CI, 1.04 to 2.5; P =.03). Multivariate analysis results showed that female gender was an independent predictor for a postoperative TIA or stroke (OR, 1.7; CI, 1.1 to 2.6; P =.03). Further analysis disclosed that women who were asymptomatic were at greater risk than were men for postoperative stroke or mortality (OR, 2.3; CI, 1.3 to 3.9; P =.003). Conversely, there was no gender association for postoperative stroke or mortality in the consideration of only patients who were symptomatic (OR, 1.0; CI, 0.45 to 2.1; P =.95). The interaction between women and preoperative symptoms approached significance (P =.07) with respect to postoperative stroke and mortality rate, which suggests that the gender effect could be influenced by the clinical presentation. CONCLUSION: The combined TIA or stroke and stroke or mortality rates are higher in women as compared with men in the postoperative period, but these risks remain acceptable when CEA is performed for appropriate indications. The interaction between symptoms and gender suggests that, in patients who are asymptomatic, women are more likely than are men to have early complications. However, there is no gender difference in patients who are symptomatic. Therefore, despite a low postoperative complication rate, CEA is appropriate in both women who are asymptomatic and women who are symptomatic only if the postoperative TIA, stroke, and mortality rates are appreciably lower than in the natural history of medical management of these patients.

Aged↗
PubMed2002

Contemporary results of juxtarenal aneurysm repair.

OBJECTIVE: The increasing use of aortic endografts predictably will add to the complexity of open abdominal aortic aneurysm (AAA) repair and, therefore, the proportion of surgically treated infrarenal AAAs that are juxtarenal in location (JRA) will grow. This study reviews a single-center experience with JRAs. METHODS: Between June 1994 and December 2000, 138 patients underwent elective repair of a JRA, comprising 16.1% of 859 consecutive asymptomatic and intact symptomatic nonruptured infrarenal AAAs repaired over the same period. All patients with JRA needed proximal suprarenal clamping (SRC) or supravisceral (SVC) clamping. Patient demographics, selected risk factors, and operative details were recorded. Univariate analyses of selected risk factors for an adverse perioperative event were assessed, and multivariate analyses were performed with linear and logistic regression with backwards selection. RESULTS: SRC was used in 95 patients (69%), and 43 patients (31%) underwent SVC. The mortality rate was 5.1% (7/138) for JRA repair, and 2.8% (20/720) for infrarenal AAA repair (P =.03). The mortality rate was significantly greater for those patients who received SVC compared with SRC (11.6% versus 2.1%; P =.02). Multivariate analysis identified SVC position as the only independent predictor of mortality (odds ratio [OR], 6.1; 95% CI, 1.1 to 32.9; P =.035). Transient renal insufficiency occurred in 39 patients (28.3%), but only eight patients (5.8%) needed dialysis. Patients who had SVC had a significantly greater rate of renal insufficiency than those who received SRC (41.9% versus 22.1%; P =.02). Multivariate analysis showed SVC position (OR, 3.3; 95% CI, 1.4 to 7.8; P =.008), diabetes (OR, 3.7; 95% CI, 1.1 to 12.9; P =.04), and preoperative renal insufficiency (OR, 5.8; 95% CI, 2.2 to 15.4; P <.001) were independent predictors of postoperative renal insufficiency. Renal ischemia during proximal clamping cannot alone explain renal complications because clamp time was shorter in patients with SVC (24.9 +/- 2.4 minutes versus 32.2 +/- 1.5 minutes; P =.009). CONCLUSION: JRA repair can be accomplished with a low mortality rate, but a more proximal clamp position may adversely affect outcome in these patients. Postoperative renal insufficiency is related to diabetes, preoperative renal insufficiency, and SVC position. These results suggest SRC is safer than SVC for proximal aortic clamp control of JRAs. Although clamp level must be tailored to patient anatomy, outcome may be improved if the clamp level can be kept distal to the superior mesenteric artery origin.

Aged↗