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Biomedical subjects

L Mathiak

Publications and source records attributed to L Mathiak.

17 recordsLinked to original sources
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1997

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↗
PubMed1995

Follow-up of primary Palmaz-Schatz stent placement for atherosclerotic renal artery stenosis.

A Palmaz-Schatz stent was successfully placed in 92 stenotic renal arteries (76 patients) for (1) hypertension in 62 (82%), and/or (2) chronic renal failure (serum creatinine > or = 1.5 mg/dl) and preservation of renal function in 39 (51%). Patients were followed to assess clinical and angiographic 6-month outcome. Angiography, performed in 45 of 62 eligible patients (73%) and in 56 of 74 treated arteries (76%), showed restenosis occurring in 14 renal arteries (25%). Serum creatinine improved or remained stable in 78% of patients. In patients with chronic renal failure, improvement or stability was observed in 55%. Blood pressure recordings significantly decreased for the entire cohort (systolic: 168 +/- 25 to 156 +/- 22 mm Hg, p < 0.0001; diastolic: 87 +/- 11 to 81 +/- 11 mm Hg, p < 0.005), and for hypertensive patients with normal creatinine (systolic: 179 +/- 20 to 155 +/- 23 mm Hg, p < 0.0001; diastolic: 92 +/- 9 to 83 +/- 12 mm Hg, p < 0.002). These follow-up data of a prospective, nonrandomized, observational study showed that stent recanalization of atherosclerotic renal artery stenoses was beneficial with regard to renal function and blood pressure response, and had a restenosis incidence of 25%.

Aged↗
PubMed1995

Primary stent deployment in occlusive subclavian artery disease.

Primary (without antecedent balloon dilation) Palmaz stent implantation was successfully performed in 27 consecutive patients entering with 31 obstructed subclavian arteries. Stents (n = 50) were successfully deployed, using the brachial (n = 7), femoral (n = 16), or combined (n = 8) approach, to revascularize 31 subclavian vessels [8 occluded (26%); 23 stenotic (74%)], using a 6 or 7.5 French delivery system. The indications for intervention were arm claudication in 8 patients (30%), subclavian steal syndrome in 11 patients (41%), angina pectoris secondary to impaired blood flow to the left internal mammary artery coronary bypass in 6 patients (22%), and recanalization of a left subclavian occlusion to permit central arterial access and performance of a second interventional procedure 2 patients (7%). The percent diameter stenosis improved from 85 +/- 12% to 6 +/- 7% (P < 0.001); and, the peak and mean translesion gradients decreased, respectively, from 56 +/- 35 mm Hg to 3 +/- 4 mm Hg (P < 0.01), and 29 +/- 18 mm Hg to 2 +/- 2 mm Hg (P < 0.01). Procedural complications encountered were one stent dislodgement with migration into and uneventful deployment within the right external iliac artery, and two brachial artery repairs. No acute vessel closures, deaths, myocardial infarctions, cerebrovascular accidents, transient ischemic attacks, or need for transfusions occurred. Therefore, primary subclavian artery stent deployment can be performed using low-profile sheath systems with excellent success (100%), resulting in immediate restoration of pulsatile flow, and few complications. The incidence of lesion recurrence remains for follow-up studies.

Adult↗
PubMed1994

The use of Gianturco-Roubin flexible metallic coronary stents in old saphenous vein grafts: in-hospital outcome and 7 day angiographic patency.

After placement of a Gianturco-Roubin metallic, coiled coronary stent(s) following balloon angioplasty (PTCA), a pre-discharge (7 day) angiogram determined the patency of the old coronary bypass vein graft(s) (SVG) (> or = 5 years remote from their last surgery, mean age: 8.5 +/- 1.8 years). Metallic, coiled stents were successfully deployed in 95/96 (99%) patients within 100/101 (99%) SVGs. The indications for deployment were threatened [81 patients (84%)] or acute [15 patients (16%)] vein graft closure following PTCA. Intragraft urokinase infusion was performed in 17 patients (17%) [6 patients with baseline occlusions; 11 with abrupt closure post PTCA]. Complications encountered included three (3%) in-hospital deaths (two procedure related) two (2%) Q wave myocardial infarctions, six (6%) non-Q wave myocardial infarctions, and 22 (22%) bleeding problems. These included, not mutually exclusively, 21 (22%) requiring transfusions, six (6%) cases of gastrointestinal bleeding, six (6%) pseudoaneurysms, five (5%) retroperitoneal haemorrhages and two (2%) cerebrovascular accidents. All patients received dipyridamole, aspirin, dextran, and anticoagulation (heparin 10-20,000 U intra-procedurally); a heparin infusion was continued for 5 +/- 1 days, despite warfarin administration which attained a therapeutic prothrombin time (PT) (1.5-2 times control) by 3 +/- 1 days. Out of the 95 successfully treated patients, six with eight stented grafts were ineligible for pre-discharge angiography. Of the six, three died in hospital (four SVGs), one had an intracerebral haemorrhage (one SVG), and two were asymptomatic patients with chronic renal failure (three SVGs).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Stenting of a renal artery stenosis achieves better relief of the obstructive lesion than balloon angioplasty.

A balloon-expandable (Palmaz-Schatz) stainless steel stent was utilized following balloon angioplasty (PTRA) to determine if the obstructive lesion, using quantitative methods (automated measuring the diameter stenosis, and transstenotic peak systolic and mean pressure gradients), was significantly further reduced or abolished. Hemodynamic transstenotic gradient and stenoses measurements were made during 21 renal artery stenting procedures; prior and following PTRA, and subsequent to stent deployment. The stent sizes placed in the renal arteries were 5 mm (19%), 6 mm (67%), and 7 mm (14%). The results were as follows: [table: see text] The balloon-expandable (Palmaz-Schatz) stent significantly further reduced, and in fact effectively abolished, the obstructive renal artery lesion in comparison to balloon angioplasty (PTRA). The stent's effectiveness with regard lesion recurrence, maintenance, and preservation of renal function; cure or improved management of hypertension; and survival will be determined by careful clinic follow-up.

Aged↗
PubMed1991

Angiographic follow-up and clinical outcome of 126 patients after percutaneous directional atherectomy (Simpson AtheroCath) for occlusive peripheral vascular disease.

Angiographic and clinical follow-up data were obtained in 115/126 patients who underwent directional atherectomy for peripheral vascular disease; of the 126, ten were excluded for appropriate reasons and one was lost to follow-up. Thus, 115/116 successful atherectomy patients (99%) had follow-up of 182/213 lesions (86%): 74 patients (64%) with angiography (mean time 5.4 mon), and 41 patients (36%) clinically. One hundred twenty-eight of 183 lesions (70%) had angiographic follow-up; the lesion recurrence as a stenosis or as an occlusion was 53%. Lesion distribution did not differ between angiography and clinical follow-up groups: nearly 85% were within the superficial femoral or popliteal arteries. Despite data stratification, angiographic follow-up indicated that patients after successful directional atherectomy, at a mean follow-up time of 5 mos, have more than a 50% lesion recurrence rate. Although directional atherectomy (Simpson AtheroCath) utilizing present techniques has excellent primary success and acceptable complication rates, angiographic follow-up statistics are bothersome.

Aged↗
PubMed1990

Percutaneous transluminal angioplasty in patients greater than or equal to 5 years after their last coronary bypass graft surgery.

Angioplasty (PTCA) was successfully performed in 257 of 304 patients (85%) greater than or equal to 5 years after their last bypass surgery. A lesion was successfully dilated in 496 of 566 vessels attempted (88%): 332/386 coronary arteries (86%) and 164/180 vein grafts (91%). Significant complications included: 8 (2.6%) mortalities, 4 (1.3%) emergency surgeries, 13 (4.3%) Q-wave myocardial infarctions, and 14 (4.6%) distal embolizations. Distal embolization occurred in 13/180 (7%) vein graft lesions dilated and usually resulted in a non-Q-wave infarction (4/13 distal embolizations). A second PTCA was performed on 89 (35%) patients: 44% of them had lesion recurrence; 20% a new lesion requiring dilatation; and 30% both recurrence and new lesion. Follow-up (mean 3.7 years) revealed 78% of patients having an improved anginal status, and 58% no angina. The cumulative probability of survival at 60 months was 88 +/- 3%. Angioplasty can be effectively employed in patients greater than or equal to 5 years remote from their last bypass surgery in native arteries or saphenous vein grafts with good procedural and long-term success. Vein graft age inherently does not appear to be a contraindication to angioplasty.

Aged↗
PubMed1990

Percutaneous transluminal aortic valvuloplasty--the acute outcome and follow-up of 149 patients who underwent the double balloon technique.

Double balloon percutaneous transluminal aortic valvuloplasty (PTAV) was performed on 149 patients (76 male (51%), mean age 76 +/- 11 years) whose symptoms included severe congestive heart failure in 127 cases (82%), syncope in 21 (14%) and angina in six (4%). Significant changes (P less than 0.05) in peak systolic (83 +/- 36 to 38 +/- 30 mmHg) and mean gradient (68 +/- 25 to 36 +/- 21 mmHg), and aortic valve area (0.6 +/- 0.2 to 1.0 +/- 0.4 cm2) were achieved in 130/149 patients (87%). Complications included an overall in-hospital mortality of 13%, (10.0% excluding the six deaths occurring in 18 moribund patients), a neurologic deficit incidence of 3%, and surgical arterial entry site repair 3.0% (14/47) of patients. Multivariate analysis identified congestive heart failure (NYHA Class IV), left ventricular ejection fraction, cardiac output and coronary artery disease as independent variables significantly affecting in-hospital mortality. Predictors of poor long-term survival were degree of heart failure, and coronary artery disease. The cumulative probability of survival at 24 months was 52 +/- 5% (excluding non-cardiac deaths, was 66 +/- 3%). Follow-up (mean time: 16 +/- 7 months) of 130 patients discharged alive revealed 41 late deaths (26 cardiac related). Sixty-two patients (70%) were symptomatically improved; 17 patients had symptom recurrence and underwent repeat valvuloplasty, and 10 patients valve replacement. Follow-up catheterization of 18 asymptomatic patients revealed that 11 patients had silently restenosed. These data indicate that aortic valvuloplasty is a palliative therapy for elderly patients, who are poor surgical candidates, with symptomatic calcific aortic stenosis with reasonable clinical success and long-term survival when considering their clinical status, but with a significant restenosis rate.

Aged↗
PubMed1989

Percutaneous transluminal aortic valvuloplasty: acute outcome and follow-up of 125 patients.

Percutaneous transluminal aortic valvuloplasty was performed on 125 patients (59 men [47%], mean age 76 +/- 13 years) between July 1986 and May 1988, with presenting symptoms of severe congestive heart failure in 88 (70%), moribund state in 15 (12%) and syncope in 17 (14%). Surgical valve replacement was considered unsuitable in 79% of cases. A multiple balloon technique was utilized in 119 patients (95%). Valvuloplasty produced significant changes in peak pressure gradient (87 +/- 38 to 32 +/- 17 mm Hg), mean pressure gradient (70 +/- 26 to 30 +/- 13 mm Hg) and valve area (0.6 +/- 0.2 to 1.0 +/- 0.3 cm2). Complications included: in-hospital mortality in 10% (6 of 13 deaths in moribund patients), neurologic deficit in 3% and myocardial infarction in 2%. Arterial repair was required at 12 (4%) of 325 entry sites. Multivariate analysis identified severe congestive heart failure, preprocedure left ventricular ejection fraction and cardiac output as the only independent variables significantly affecting mortality. The cumulative probability of survival at 12 months was 62 +/- 6% and, excluding non-cardiac deaths, was 77 +/- 5%. At a mean of 12 +/- 4 months' follow-up, 55 of 72 patients were symptomatically improved; 10 patients with symptom recurrence underwent repeat valvuloplasty and 5 had valve replacement. Cardiac catheterization was repeated in 12 symptomatically improved patients, 9 of whom had valve restenosis. These data indicate that aortic valvuloplasty should be considered a palliative therapy for elderly patients with symptomatic calcific aortic stenosis who are poor surgical candidates.

Aged↗
PubMed1989

Percutaneous atherectomy of occlusive peripheral vascular disease: stenoses and/or occlusions.

Percutaneous atherectomy was performed using the Simpson Atherocath on 131 patients (87 male, 66%) with a mean age of 65 years. Clinical characteristics included evidence of significant coronary disease in 50%, hypertension in 46%, diabetes in 41%, and prior neurologic deficit in 32% of patients. The indication for atherectomy was claudication in 114 (87%) and rest pain, gangrene, or ulcer in 17 patients (13%). Atherectomy was successfully performed in 136/139 stenoses (98%) and in 56/56 occluded vessels with or without prior balloon angioplasty. No serious complications resulting in limb loss or emergency vascular surgery were encountered. Histopathology of retrieved specimens showed that 66% had atheromatous plaque, 45% had tunica media, and 30% had a form of thrombus. Material obtained from an occluded vessel was more likely to have thrombus and tunica media present than that from a stenosis (P less than 0.02 and P less than 0.05, respectively). Early angiographic follow-up (mean time, 17 weeks) showed a relatively low (17%) lesion recurrence rate. Percutaneous atherectomy can be successfully utilized in stenotic and occluded peripheral arteries with good success and no serious complications; stenoses appear to have a low recurrence rate.

Aged↗
PubMed1989

[Complex coronary angioplasty. I. Single or multiple dilatations in the involvement of several vessels in patients with coronary heart disease].

Coronary angioplasty was successfully performed in 658 of 752 multivessel disease patients. One lesion was attempted in 338 patients (45%), 2 or more in 414 patients (55%). Complications occurred in 39 patients (5.2%): 19 (2.5%) had a transmural infarction; 26 (3.5%) urgent surgery, and 14 (1.9%) died. Recurrence occurred in 233 (35%) of 658 patients with 162 (94.7%) of 171 having a successful 2nd angioplasty. Clinical improvement (followup: 31 months) remained in 81% of successful patients. Survival was not affected by the number of dilatations performed but was adversely affected by the presence of prior aorto-coronary bypass, surgery and ventricular dysfunction. Angioplasty can be an effective treatment without the need to dilate all vessels.

Angioplasty, Balloon, Coronary↗
PubMed1989

[Complex coronary angioplasty. II. Dilatation of the multiple lesions in stenosis of one or several coronary vessels].

Angioplasty (PTCA) was successfully performed in 404 (94%) of 428 patients. Two lesions were attempted in 74%, 3 in 21% and 4 or more in 6% of cases. Significant complications included: 11 (2.5%) transmural infarctions, 9 (2.1%) emergency surgeries, and 6 (1.4%) mortalities. A lesion recurrence occurred in 106 (26%) of 404 patients with 81 (91%) of 89 patients having a successful 2nd PTCA. A 2nd recurrence occurred in 15 (19%) of 81 patients with 13 of 15 patients having a successful 3rd PTCA. Followup (mean: 28.3 months) showed an improved anginal status in 83% of patients. The probability of survival at 51 months was 93%. Multiple lesion PTCA in carefully selected patients has a good success rate and an acceptable complication rate.

Angioplasty, Balloon, Coronary↗
PubMed1988

Probe, a balloon wire: initial experience.

Coronary angioplasty is unsuccessful in less than 3-5% of cases because the balloon catheter fails to follow a guidewire that has traversed a lesion. Between June 1986 and August 1987, 31 lesions were unable to be crossed with at least two standard angioplasty catheters. Finally, a 2.0-mm-diameter Hartzler LPS (ACS) was utilized and successfully crossed and dilated 16 out of 31 lesions (52%). In the remaining 15 lesions, the Probe (USCI) 2.0 mm diameter x 1.5 cm long balloon wire was able to cross the lesions in 13 (82%) and successfully dilated 12. In one case, lesion rigidity prevented the balloon from expanding at 14 atm. A right coronary artery lesion was attempted in 11 cases, and a left anterior descending and circumflex artery lesion in two patients each. No complications were encountered. In seven out of 12 successful Probe cases, a larger balloon catheter was used to further dilate the artery. This new balloon wire has increased our success rate in severe stenoses and in tortuous vessels with severe distal lesions, in which presently available angioplasty equipment has failed.

Angioplasty, Balloon↗