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Biomedical subjects

R R Heuser

Publications and source records attributed to R R Heuser.

At least 55 records · Page 3Linked to original sources
PubMed1995

Endovascular techniques in adult aortic coarctation: the use of stents for native and recurrent coarctation repair.

PURPOSE: To report initial experiences with stent implantation in the treatment of native and recurrent aortic coarctation in adults. METHODS: Two adult patients were diagnosed with aortic coarctation: in one, the native aorta was involved, and in the other, the stenosis involved a prior coarctation repair. Both patients were offered and selected angioplasty with possible stent implantation as an alternative to surgery. RESULTS: In the patient with recurrent narrowing, thrombolysis and balloon dilation preceded the successful deployment of three Palmaz stents along the grafted segment. In the case of native disease, one Palmaz stent was implanted primarily at the site of a critical, focal stenosis. No complications were encountered, and recovery was uneventful. Follow-up at 12 and 6 months, respectively, showed sustained clinical improvement with resolution of symptoms and excellent hemodynamic values. CONCLUSIONS: The positive outcome in these early cases supports further evaluation of the efficacy of adjunctive or primary stenting for treatment of native or recurrent aortic coarctation in adults.

Aortic Coarctation↗
PubMed1994

Long-term angiographic and clinical outcome after implantation of balloon-expandable stents in aortocoronary saphenous vein grafts.

Balloon angioplasty of aortocoronary saphenous vein graft lesions is associated with high restenosis and clinical event rates. The goal of this multicenter study was to assess long-term angiographic and clinical outcome of patients electively treated with single Palmaz-Schatz stents in aortocoronary saphenous vein grafts. In 198 patients (209 lesions), elective placement of single Palmaz-Schatz stents was attempted. Angiography was performed at baseline, immediately after stent placement, and at 6-month follow-up. Stent placement was successful in 98.5% of patients. One patient (0.5%) had stent thrombosis. Restenosis occurred in 34% (45 of 133) of the restudied lesions. Restenosis was lower in de novo lesions than in restenotic lesions (22% vs 51%, p < 0.001). Ostial lesions had a higher restenosis rate than nonostial lesions (61% vs 28%, p = 0.003). Freedom from death, myocardial infarction, coronary artery bypass surgery, and repeat angioplasty was present in 70% of patients. Eighty-two percent of patients with de novo lesions remained event-free at 1 year, whereas only 55% of patients with prior angioplasty were event-free at 1 year (p < 0.001). The use of the Palmaz-Schatz stent for the treatment of focal, de novo, aortocoronary saphenous vein graft lesions is associated with a high procedural success rate, a low angiographic restenosis rate, and low clinical event rates, including the need for repeat revascularization. The results of this study need validation by a prospective randomized trial comparing stent implantation with angioplasty.

Aged↗
PubMed1994

Immediate arterial hemostasis after cardiac catheterization: initial experience with a new puncture closure device.

A novel device for obtaining arterial hemostasis after invasive procedures was tested in 30 patients undergoing diagnostic catheterization (26 patients) or coronary angioplasty (4 patients). The device is deployed through an arterial sheath and forms a positive mechanical seal both inside and outside the defect in the arterial wall. The components are all bioabsorbable. Thirteen patients received a heparin bolus during the catheterization procedure. The activated clotting time recorded in 15 patients just prior to device deployment averaged 264 sec. 29 of 32 attempted device deployments were successful (91%); and the remaining 3 devices pulled completely out as called for by design in the event of incomplete deployment. Twenty-nine patients ultimately achieved successful hemostasis using the device, with the other patient receiving manual hemostasis. Of these 29, hemostasis was immediate and complete in 19 patients. Light digital pressure was required in another 8 patients for less than 5 min. There was minor delayed bleeding requiring supplemental light pressure in several cases. A total of 11 patients required supplemental pressure in addition to the hemostasis device. The use of bolus heparin was significantly (P = 0.05, Fisher's exact test) related to the requirement for supplemental pressure. Three patients developed hematomas, one of which was present prior to device deployment. The other two patients had received bolus heparin. No patient required transfusion or surgical repair. There was no change in the ankle/brachial systolic blood pressure index after device deployment or at late (30-60 day) follow-up. Ultrasound studies revealed no significant pathology relative to the device.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1994

Recombinant human superoxide dismutase (h-SOD) fails to improve recovery of ventricular function in patients undergoing coronary angioplasty for acute myocardial infarction.

BACKGROUND: Animal studies have demonstrated a burst of oxygen free radical generation after reperfusion of ischemic myocardium that could be blocked by administration of the free radical scavenger recombinant human superoxide dismutase (h-SOD). A multicenter, randomized, placebo-controlled clinical trial was designed to test the hypothesis that free radical-mediated reperfusion injury could be reduced by intravenous administration of h-SOD begun before percutaneous transluminal coronary angioplasty (PTCA) in patients with acute transmural myocardial infarction. METHODS AND RESULTS: One hundred twenty patients were randomized to receive placebo (n = 59) or h-SOD (n = 61) given as a 10-mg/kg intravenous bolus followed by a 60-minute infusion of 0.2 mg.kg-1.min-1. Left ventricular function was analyzed via paired contrast left ventriculograms performed before PTCA and after 6 to 10 days and paired radionuclide ventriculograms performed within 24 hours of PTCA and after 4 to 6 weeks. Both h-SOD- and placebo-treated patients showed improvement in global and regional left ventricular function after successful reperfusion. Compared with the placebo group, no additional improvement was observed in the patients treated with h-SOD. CONCLUSIONS: The results of this clinical trial failed to demonstrate a beneficial effect of h-SOD on global or regional left ventricular function in patients who underwent successful PTCA for treatment of acute myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed1993

New treatment approach for chronic total occlusions of saphenous vein grafts: thrombolysis and intravascular stents.

Balloon dilation of saphenous vein graft (SVG) occlusions has a lower success rate than angioplasty of native coronary arteries. To improve this outcome, a new therapy for chronic total SVG occlusions was developed. In three aortocoronary bypass graft patients with class III-IV angina and chronic occlusion of the SVGs to the left anterior descending artery (age of occlusions: 2-24 wk, age of graft 1-13 yr), standard recanalization was achieved with a guide wire and intracoronary urokinase infusion (0.5-1.0 million unit bolus followed by 100,000 IU/hr for 11-24 hr; mean infusion time: 19.7 hr). In each patient, a residual focal stenosis (average 82.5%) was successfully dilated and stented (single 4.0 mm Palmaz-Schatz in two patients and a 3.5 mm Strecker stent in the other). All patients had complete relief of symptoms and no sequelae. During a mean 7.7 mon follow-up, 6-mon arteriographic evaluation in two patients showed minimal intra-stent narrowing (26% and 34%). In the Strecker stent patient, the device proved too small for the vein graft, leading to an 89% stent stenosis found on follow-up arteriography at 5 mon. The stent was redilated successfully with a 5% residual narrowing. After urokinase recanalization of chronic total SVG occlusions, intravascular stents may improve the long-term results seen with conventional SVG angioplasty.

Aged↗
PubMed1993

The use of a new wire in a 6-year-old coronary artery occlusion: the Jagwire recanalization guidewire.

Chronic total occlusions are difficult to treat, usually because they cannot be crossed with a guidewire or dilating catheter. A variety of angioplasty systems designed to facilitate coronary angioplasty of chronic total occlusions have been used. We report the case of a 6-year-old occlusion of the right coronary artery that was treated with the Jagwire, a new guidewire designed for use in challenging lesions. This device successfully crossed the lesion and resulted in a successful angioplasty. The patient's angina dramatically improved following the procedure.

Angioplasty, Balloon, Coronary↗
PubMed1993

Preliminary observations on the use of the Palmaz stent in the distal portion of the abdominal aorta.

The opportunities to avoid surgical treatment of distal abdominal aortic occlusive disease are expanding because of the proliferation in catheter-based techniques. Since January 1990, 24 symptomatic patients with distal abdominal disorders have been treated percutaneously with balloon angioplasty and intraluminal stenting. A total of 38 Palmaz stents were deployed at distal abdominal aortic sites; 21 additional iliac stents were implanted. After the procedure all patients improved clinically, and 83% (21/24) improved by objective measurement (average ABI 0.93 +/- 0.21). Three access-related complications occurred (two hematomas, one thrombus), but no complications were related to the stents. At up to 29 months of follow-up (average 10.3 +/- 6.7 months), clinical improvement persists in all patients (average ABI 0.93 +/- 0.22). In 11 patients eligible for follow-up aortography, all aortic stents are patent without evidence of restenosis. With the low likelihood for restenosis in the abdominal aorta, the long-term outcome of aortic stenting looks promising and may equal or surpass that found in the iliac region.

Aged↗
PubMed1993

Angioscopy: a valuable tool in the deployment and evaluation of intracoronary stents.

Intracoronary stents were designed to improve balloon dilation results; however, to accomplish this, various criteria of optimal stent deployment must be met. Standard imaging techniques are neither sensitive nor specific enough for intraprocedural use in the verification of these implantation parameters. To assess the usefulness of angioscopy in the procedural and follow-up evaluations of Palmaz-Schatz and Strecker coronary stent deployment, 17 patients underwent angioscopy, 15 during stent placement and 2 during follow-up for stent restenosis. In the latter cases, thrombus formation was suspected; however, angioscopy showed tissue subtotally occluding the lumen without thrombus, so thrombolytic therapy was avoided. Similarly, among the 15 intraprocedural assessments, angioscopy disclosed intravascular thrombus unappreciated on angiography in two cases; another patient at high risk for intravascular thrombus was found not to have clot. In four patients, angioscopy disclosed residual narrowing in need of redilation at the Palmaz-Schatz stent articulation site. Thus in 9 (53%) of 17 stent patients, angioscopic findings either guided therapeutic selection or significantly modified the anticipated procedure. Angioscopy offers important information critical to the accurate placement and evaluation of intracoronary stents.

Aged↗
PubMed1993

Use of the Doppler guide wire for intraluminal diagnosis to facilitate coronary intervention.

The FloWire Doppler flow guide wire has recently been approved for intracoronary application, joining angioscopy and intravascular ultrasonography as new methods for transluminal evaluation of coronary lesions. The 0.018-inch FloWire provides a high-fidelity continuous Doppler signal. Velocity measurements are continuously displayed on the FloMap monitor in a gray-scale spectral pattern, providing quantitation of an entire spectral distribution of flow velocities. This torquable, steerable guide wire can be used in small and distal branches of the coronary tree. We describe the clinical use of the FloWire Doppler guide wire in three patients who had coronary anatomic abnormalities that could not be assessed by other techniques. In each case the Doppler guide wire facilitated analysis of the physiologic significance of the coronary stenosis. The information gained was crucial in selecting safe and effective treatment for these patients.

Aged↗
PubMed1992

Intracoronary stent implantation via the brachial approach: a technique to reduce vascular bleeding complications.

To reduce the incidence of vascular complications of intracoronary stent implantation, we used the brachial approach. We attempted implantation of the Palmaz-Schatz stent via the brachial artery approach at 10 lesions in 9 patients. Stent delivery was successful at 8 lesions. Balloon angioplasty was successfully performed in the 2 failed cases, 1 of whom required surgical repair of the brachial artery. Intravenous anticoagulation was uninterrupted from the time of stent placement until therapeutic prothrombin times from oral warfarin therapy were obtained. Neither acute nor long-term major bleeding occurred in the 9 patients. There were no embolic events, myocardial infarctions, or deaths. One subacute thrombosis occurred, and the patient underwent bypass surgery. To evaluate the risks and benefits of the brachial approach, we compared these 9 patients with 41 who had stent placement by the femoral approach during the same period. Lesion characteristics were similar in these 2 groups. There were no significant differences in the success rate or angiographic outcome between the 2 groups. Seven (17%) patients in the femoral group had vascular access complications requiring surgery, compared with 1 (11%) in the brachial group. No patient in the brachial group required transfusion, compared with all 7 of the patients who had femoral vascular complications. The potential reduction in bleeding complications makes the brachial approach to stent implantation attractive in selected patients.

Aged↗
PubMed1992

ACS RX flow support catheter as a temporary stent for dissection or occlusion during balloon angioplasty: initial experience.

The ACS RX flow support catheter, which functions as a temporary stent, was placed successfully during four procedures in three patients who had suboptimal results following angioplasty. This investigational device allowed prolonged perfusion and supported the vessel wall when coronary blood flow was compromised, avoiding emergent coronary artery bypass graft surgery during two procedures. In the remaining procedures the device was used as a bridge to surgery. These early applications of the flow support catheter following failed balloon angioplasty suggest a rapid, effective alternative to the autoperfusion balloon when it fails or is contraindicated because of the lesion location.

Aged↗
PubMed1992

Palmaz-Schatz stent implantation in stenosed saphenous vein grafts: clinical and angiographic follow-up.

Balloon-expandable stents may reduce the restenosis rate following coronary angioplasty. To evaluate this potential in saphenous vein grafts, 26 patients with 30 discrete stenoses underwent conventional balloon dilation and successful Palmaz-Schatz stent implantation as part of a multicenter trial. All patients had resolution of their angina following the procedure. In a mean 5-month follow-up period, 14 patients (54%, 16 lesions) had repeat arteriography; two patients (14%) developed recurrent ischemia ascribed to their venous grafts from in-stent restenosis (2 of 16 lesions, 13%). Two asymptomatic patients (8%) died: one from cardiac arrest (stent patent) and one from stroke (no autopsy). The clinical recurrence rate (cardiac death, myocardial infarction, bypass surgery, repeat angioplasty, or symptom recurrence) was 15%. These preliminary results show trends toward an improved primary success rate with combined vein graft angioplasty/stenting and a lower restenosis rate in stented saphenous vein grafts, but continuing follow-up will be needed to verify these observations.

Aged↗
PubMed1992

Alterations of phasic coronary artery flow velocity in humans during percutaneous coronary angioplasty.

BACKGROUND AND OBJECTIVES: Studies using Doppler catheters to assess blood flow velocity and vasodilator reserve in proximal coronary arteries have failed to demonstrate significant improvement immediately after coronary angioplasty. Measurement of blood flow velocity, flow reserve and phasic diastolic/systolic velocity ratio performed distal to a coronary stenosis may provide important information concerning the physiologic significance of coronary artery stenosis. This study was designed to measure these blood flow velocity variables both proximal and distal to a significant coronary artery stenosis in patients undergoing coronary angioplasty. METHODS: A low profile (0.018-in.) (0.046-cm) Doppler angioplasty guide wire capable of providing spectral flow velocity data was used to measure blood flow velocity, flow reserve and diastolic/systolic velocity ratio both proximal and distal to left anterior descending or left circumflex coronary artery stenosis. These measurements were made in 38 patients undergoing coronary angioplasty and in 12 patients without significant coronary artery disease. RESULTS: Significant improvement in mean time average peak velocity was noted in distal coronary arteries after angioplasty (before 19 +/- 12 cm/s; after 35 +/- 16 cm/s; p less than 0.01). Increases in proximal average peak velocity after angioplasty were less remarkable (before 34 +/- 18 cm/s; after 41 +/- 14 cm/s; p = 0.04). Mean flow reserve remained unchanged after angioplasty both proximal (1.5 +/- 0.5 vs. 1.6 +/- 1; p greater than 0.10) and distal (1.6 +/- 1 vs. 1.5 +/- 0.8; p greater than 0.10) to a coronary stenosis. Before angioplasty, mean diastolic/systolic velocity ratio measured distal to a significant stenosis was decreased compared with that in normal vessels (1.3 +/- 0.5 vs. 1.8 +/- 0.5; p less than 0.01). After angioplasty, distal abnormal phasic velocity patterns generally returned to normal, with a significant increase in mean diastolic/systolic velocity ratio (1.3 +/- 0.5 vs. 1.9 +/- 0.6; p less than 0.01). Phasic velocity patterns and mean diastolic/systolic velocity ratio measured proximal to a coronary stenosis were not statistically different from values in normal vessels (1.8 +/- 0.8 vs. 1.8 +/- 0.5; p greater than 0.10) and did not change significantly after angioplasty (1.8 +/- 0.8 vs. 2.13 +/- 0.9; p greater than 0.10). CONCLUSIONS: Flow velocity measurements may be performed distal to a coronary stenosis with the Doppler guide wire. Phasic velocity measurements made proximal to a coronary stenosis differed from those in the distal coronary artery. Both proximal and distal flow reserve measurements made immediately after angioplasty were of limited utility. Changes in distal flow velocity patterns and diastolic/systolic velocity ratio appeared to be more relevant than the hyperemic response in assessing the immediate physiologic outcome of coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1992

The use of the holmium:YAG laser in coronary disease: the utility of a unique lensed fiber catheter.

Alternatives to balloon angioplasty, which has a restenosis rate of 25%-68%, are being sought for patients at high risk for restenosis. The mid-infrared holmium laser may have properties more advantageous for coronary angioplasty than the ultraviolet excimer laser. The Coronary HaloCath (Trimedyne, Inc.) has a diverging lens that allows the beam diameter to approximate the catheter tip diameter, increasing the size of the channel that can be created by laser ablation. This unique ability may make it more efficacious in treating arteriosclerotic disease. This device was used to treat: 1) a chronic total occlusion, creating a recanalized diameter larger than the catheter diameter; and 2) an ostial right coronary stenosis, which opened more readily than would have been expected with balloon angioplasty. The Coronary HaloCath may prove useful in difficult-to-treat coronary lesions.

Aged↗
PubMed1991

Holmium laser angioplasty after failed coronary balloon dilation: use of a new solid-state, infrared laser system.

A new solid-state laser system was used in a case of saphenous vein graft occlusion untreatable by standard very low-profile balloon angioplasty. The 2100 nm infrared pulsed thulium/holmium: YAG laser successfully recanalized an obtuse marginal bypass graft without complications. The holmium laser has several advantages over excimer systems and may prove an effective adjunct or alternative to coronary balloon angioplasty.

Aged↗
PubMed1989

Angina and vasospasm at rest in a patient with an anomalous left coronary system.

An anomalous left main coronary artery with passage between the right ventricular infundibulum and aortic root has been incriminated as the causation of sudden death in a small number of individuals, many of whom are quite young. Mechanical features such as angulation and compression are most often incriminated. A 59-year-old man with such a coronary anomaly who had chest pain at rest, ST segment elevation, and ventricular tachycardia, but who had no evidence of effort-related myocardial ischemia, is reported. Improvement in the degree of coronary tone in the anomalous left main coronary with intracoronary nitroglycerin administration was demonstrated. This represents the first report of an individual with an anomalous left main coronary system with ventricular tachycardia/ventricular fibrillation and documented vasospasm in the anomalous artery.

Angina Pectoris↗