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Biomedical subjects

G Dorros

Publications and source records attributed to G Dorros.

At least 19 recordsLinked to original sources

Global experience in cervical carotid artery stent placement.

The purpose of this article is to review and update the current status of carotid artery stent placement in the world. Surveys to major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent information from these 24 centers in addition to 12 new centers has been obtained to update the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 5,210 procedures involving 4,757 patients. There was a technical success of 98.4% with 5,129 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 134 transient ischemic attacks (TIAs) for a rate of 2.82%. Based on the total patient population, there were 129 minor strokes with a rate of occurrence of 2.72%. The total number of major strokes was 71 for a rate of 1.49%. There were 41 deaths within a 30-day postprocedure period resulting in a mortality rate of 0.86%. The combined minor and major strokes and procedure-related death rate was 5.07%. Restenosis rates of carotid stenting have been 1.99% and 3.46% at 6 and 12 months, respectively. The rate of neurologic events after stent placement has been 1.42% at 6-12-month follow-up. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients that are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have not changed significantly since the first survey results. Cathet. Cardiovasc. Intervent. 50:160-167, 2000.

Carotid Stenosis↗

Catheter-based techniques for closure of coronary fistulae.

This study details different methodologies of percutaneous closure of arteriosystemic and arteriovenous coronary fistula. Seven patients underwent transcatheter intervention of 10 fistulas, with 7 fistulas successfully closed: 6 with embolic coil devices and 1 with a covered stent obstructing the fistula ostium. The major complication encountered was one death as a result of device recoil into a major epicardial vessel. Percutaneous transcatheter closure of coronary fistulas appears to be simple, facile, and effective. However, device recoil into an undesired arterial segment, while irritating in a noncoronary arterial tree, may be catastrophic when occurring in an epicardial coronary artery.

Aged↗

Four-year follow-up of Palmaz-Schatz stent revascularization as treatment for atherosclerotic renal artery stenosis.

BACKGROUND: Stent revascularization is perceived as superior to balloon angioplasty and surgical revascularization, but the paucity of stent publications precludes even historical comparison with surgical data. METHODS AND RESULTS: Palmaz-Schatz stent revascularization of renal artery stenosis was successfully performed on 163 consecutive patients for poorly controlled hypertension or preservation of renal function. Of these, 145 were eligible for > or =6-month clinical follow-up of the effect of the procedure on renal function, blood pressure control, number of antihypertensive medications, and survival. At 4 years, systolic and diastolic blood pressures significantly decreased (from 166+/-26 to 148+/-22 mm Hg and from 86+/-14 to 80+/-11 mm Hg, respectively; P<0.05), and blood pressure control was more facile in approximately half of the patients. Creatinine decreased or remained stable in approximately two thirds of the patients. The cumulative probability of survival was 74+/-4% at 3 years, with few deaths related to end-stage renal disease. Survival was good in patients with normal (92+/-4%) baseline renal function, fair (74+/-7%) in those with mildly impaired renal function, and poor (52+/-7%) in patients with elevated baseline creatinine levels (> or =2.0 mg/dL). The combination of impaired renal function and bilateral disease adversely affected survival. CONCLUSIONS: Renal artery stent revascularization in the presence of normal or mildly impaired renal function had a beneficial effect on blood pressure control and a nondeleterious effect on renal function. Survival was adversely affected by renal dysfunction despite adequate revascularization. Early diagnosis and adequate revascularization before the onset of renal dysfunction could beneficially affect blood pressure control, preserve or prevent deterioration of renal function, and improve patient survival.

Actuarial Analysis↗

Current global status of carotid artery stent placement.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Angioplasty, Balloon↗

Catheter therapy for fontan baffle obstruction and leak, using an endovascular covered stent.

A 6 1/2-year-old (weight 20 kg) patient was found to have significant cavo-atrial obstruction and significant right-to-left shunt via multiple large fenestrations in the baffle, with oxygen saturation of 81% 3 1/2 yr after a fenestrated Fontan operation. In one session, this patient had undergone placement of a Palmaz stent at the cavo-atrial narrowing in order to increase anterograde venous return into the pulmonary artery. This was unsuccessful in improving the oxygen saturation because of the large leak in the baffle. Therefore, at a second catheterization session, two telescoping dacron-covered experimental vascular self-expanding stents were placed from the right atrial origin (distal to the hepatic veins) into the pulmonary artery connection delineated by the Palmaz stent, with complete reconstruction of the baffle and improvement in oxygen saturation to 95%.

Cardiac Catheterization↗

The acute outcome of tibioperoneal vessel angioplasty in 417 cases with claudication and critical limb ischemia.

A non-randomized, consecutive series of 417 first procedure tibioperoneal vessel angioplasty (TPVA) cases were analyzed to determine if angioplasty were an alternative revascularization technique for critical limb ischemia (CLI) and claudicants patients. TPVA was performed on 312 patients (70% male; age 66 +/- 10 years) with success attained in 406/417 cases (96%) of 605/657 lesions (92%): [461/469 stenoses (98%) and 144/188 occlusions (77%) *(P < 0.05)]. Claudication and CLI patients had similar rates of success. In claudication patients clinical success was 130/133 (98%); lesion success was 197/208 (92%); stenosis was 148/151 (98%); and occlusion was 49/57 (86%). In CLI patients clinical success was 270/284 (95%); lesion success was 408/449 (91%); stenosis was 313/318 (98%); and occlusion was 95/131 (73%). We conclude that TPVA is an effective revascularization technique for obstructed tibioperoneal vessels, with excellent success in stenotic (98%) and reasonable results in occluded vessels (77%). These data demonstrate TPVA effectiveness in CLI patients and in carefully selected claudicants with appropriate indications (severe, lifestyle limiting claudication) and readily amenable anatomy, and TPVA for CLI patients appears to be an effective revascularization technique.

Acute Disease↗

In vivo crushing of an aortic stent enables endovascular repair of a large infrarenal aortic pseudoaneurysm.

PURPOSE: To report an unusual approach to endovascular exclusion of a large aortic pseudoaneurysm. METHODS AND RESULTS: A 63-year-old male had an unsuccessful endovascular repair of an aortic anastomotic pseudoaneurysm that left an expanded, uncovered Palmaz stent lying obliquely within the aorta. After nearly 3 years, the pseudoaneurysm enlarged to 7 cm, and the patient became symptomatic. Repair of the pseudoaneurysm was accomplished by crushing the indwelling stent to allow placement of a stent-graft. CONCLUSIONS: Malpositioned stents that are hindering an endoluminal procedure may be crushed against the arterial wall in vivo to facilitate passage of endovascular instruments or devices.

Aneurysm, False↗

Stent deployment resolves a petrous carotid artery angioplasty dissection.

A patient with a symptomatic petrous carotid artery stenosis underwent balloon angioplasty, which was complicated by a flow-limiting dissection. The problem was resolved by deploying a balloon-expandable coronary stent. The patient suffered no neurologic deficit, was discharged within 12 hours, and was asymptomatic at last follow-up, 5 months after the procedure, without warfarin therapy. This therapeutic option may prove useful as a means to correct endovascular procedural complications.

Aortic Dissection↗

Stent revascularization for atherosclerotic renal artery stenosis. 1-year clinical follow-up.

Patients who had undergone stent revascularization of renal artery stenosis for poorly controlled hypertension, preservation of renal function, or both were monitored to assess the procedure's effect upon subsequent renal function and blood pressure control. At 1-year follow-up, systolic and diastolic blood pressures had significantly decreased (166 +/- 26 to 156 +/- 25 mmHg and 86 +/- 14 to 80 +/- 13 mmHg, respectively; P < 0.05), and creatinine levels decreased or remained stable in approximately two thirds of the patients. Renal artery stent revascularization appears to have a beneficial effect upon blood pressure control and a nondeleterious effect upon renal function in the majority of patients.

Aged↗

Palmaz stent compression in patients following carotid artery stenting.

UNLABELLED: Carotid artery stenting is being investigated as a therapeutic strategy for the management of bifurcation stenosis. Palmaz stents were deployed successfully in the carotid arteries of 112 patients using high-pressure balloon inflations. In 11 out of 70 patients who came for 6-mo follow-up angiography, a stent collapse was noted. Carotid ultrasound was able to detect stent collapse in only two patients at follow-up. Only one patient who had collapse of stent along its entire length was symptomatic at follow-up. Repeat balloon angioplasty was performed in 5 patients, 3 of whom had a Wallstents deployed within the Palmaz stent. CONCLUSION: Stent collapse was observed in a significant number of Palmaz stents within 6 mo of placement in the carotid arteries. These observations should influence the choice of stents for the treatment of extracranial carotid disease.

Aged↗

Coronary blood flow velocities during rotational atherectomy.

This study was designed to evaluate the alterations in doppler derived coronary blood flow velocities and flow reserve following rotational ablation. Changes in doppler derived coronary blood flow velocity variables have been valuable in assessing the physiological outcome following coronary balloon angioplasty. Rotational ablation's mechanism of plaque removal could alter distal vascular bed characteristics, and, as a result, intracoronary blood flow velocities and the coronary flow reserve. A 12-MHz doppler guidewire recorded intracoronary phasic velocities and coronary flow reserve (as assessed by the hyperemic response to adenosine [12-18 mcg intracoronary]) in 28 patients, before and after rotational ablation of 30 lesions. Adjunctive balloon angioplasty was performed in 27 of 28 patients (96%). Rotational ablation and adjunctive balloon angioplasty successfully reduced the lesion diameter (87 +/- 9% to 14 +/- 11%; P < 0.001). A significant increase in the mean distal average peak velocity (25 +/- 13 cm/sec, before; 47 +/- 22 cm/sec, after; P < 0.001), and decrease in the proximal to distal average peak velocity ratio, (2.1 +/- 1.3; to 1.2 +/- 0.4; P = 0.002) was recorded. The mean distal diastolic to systolic velocity ratio (before, 1.4 +/- 0.7; after, 1.6 +/- 0.8; P = 0.44) and the coronary flow reserve (before, 1.6 +/- 0.6; after, 1.5 +/- 0.5; P = 0.34) did not increase despite increases in distal velocities, following successful intervention. Doppler derived distal coronary blood flow velocities increased following rotational ablation and adjunctive balloon angioplasty, with resolution of transstenotic velocity gradient. Changes in distal phasic velocity pattern and coronary flow reserve, immediately after the intervention, were not useful in the assessment of the functional outcome and may be related to abnormalities in distal vascular bed vasoreactivity produced by rotational ablation.

Aged↗

Percutaneous endovascular stent-graft repair of iliac artery aneurysms.

PURPOSE: To report a percutaneous technique for endovascular repair of iliac artery aneurysms using commercially available materials. METHODS: Ten patients (9 males; mean age 65 +/- 11 years) presented with 11 isolated iliac artery aneurysms; 3 patients were asymptomatic. Stent-grafts were customized for each patient from polytetrafluoroethylene grafts with Palmaz stents sutured at either end of the tube. The devices were delivered percutaneously through standard 14F sheaths and deployed by balloon dilation. RESULTS: All iliac aneurysms were excluded without procedural incident. One patient with chronic renal insufficiency (baseline serum creatinine 1.9 mg/dL) experienced transient contrast-induced renal failure inhospital. The average hospital stay was 2.5 days (range 1 to 7). One vessel thrombosed 2 weeks following the procedure; the culprit stenosis at the site of arterial cannulation was dilated. One patient died of myocardial infarction at 6 weeks. The remaining eight grafts are patent and free of endoleak at a mean 14-month follow-up. CONCLUSIONS: This percutaneous technique appears to be an acceptable alternative to open surgical repair.

Aged↗

Evaluation of endovascular abdominal aortic aneurysm repair: anatomical classification, procedural success, clinical assessment, and data collection.

PURPOSE: To detail a methodology for evaluation of endovascular abdominal aortic aneurysm (AAA) repair that has been achieved through consensus of an international multidisciplinary team of investigators. METHODS: This schema features an anatomical classification for AAAs, a definition of procedural success, and a procedure for clinical assessment, as well as the necessary data collection forms. Patient data include demographics, procedural and clinical success, complications, and follow-up. Procedural details can be related to anatomic situations, comorbid processes, devices, and effective aneurysmal exclusion. RESULTS: These data would allow assessment of the procedures, physician learning curves, procedural indications, techniques, methodologies, the relationship of indications to success and complications, devices and subsequent graft patency, and aneurysmal exclusion. CONCLUSIONS: The use of this standardized data collection system could enable physicians and industry to better understand endovascular AAA repair and ultimately improve patient care.

Aortic Aneurysm, Abdominal↗