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K Bayazit

Publications and source records attributed to K Bayazit.

At least 37 records · Page 2Linked to original sources
PubMed1997

A comparison of the early and midterm results after dynamic cardiomyoplasty in patients with ischemic or idiopathic cardiomyopathy.

OBJECTIVE: The main goal of this study is to determine the efficiency of the cardiomyoplasty procedure on patients with cardiomyopathy of different origins (ischemic and idiopathic origins). METHOD: Between June 1993 and August 1995, 24 patients underwent dynamic cardiomyoplasty with the left latissimus dorsi muscle in our institution. Early and midterm results, as well as the changes in hemodynamics and functional status during follow-up, were compared. RESULTS: Early mortality rate was 20.8% (five patients). Concomitant coronary revascularization, a preoperative left ventricular ejection fraction below 20%, and a functional capacity of class IV (intermittently) were associated with early mortality. The mean follow-up time was 17.3 months. Survival analysis (including early mortality) extending to the twenty-fourth month revealed no difference between the ischemic and idiopathic groups (55% vs 85%, respectively, p = 0.09). Functional status improved in the both groups. Ejection fractions were improved after cardiomyoplasty in all patients, regardless of their cause. Cardiac indices were higher 6 months after the operation. Changes in pulmonary capillary wedge pressure, peak pulmonary artery pressure, and left ventricular end-diastolic volume were not significant. CONCLUSION: Although cardiomyoplasty improves functional capacity and hemodynamics in patients with both idiopathic and ischemic cardiomyopathy, the idiopathic group is thought to achieve optimal benefit with regard to lower complication rates and lower early mortality expectancy owing to the absence of concomitant coronary revascularization.

Adult↗
PubMed1996

Spinal cord protection with the use of prostacyclin during aortic occlusion.

This study was planned to investigate if prostacyclin (PGI2) would reduce spinal cord injury following aortic occlusion. Twelve dogs underwent 90 min of aortic occlusion. Six dogs received PGI2 and the remaining animals did not. PGI2 was administered at a dose of 25 ng/kg/min during occlusion of the aorta. There were five paraplegic animals in the control group and one in the PGI2 group 72 hr after aortic occlusion. Neurological recovery was better in the PGI2 group than in the control group (P < 0.05). Malondialdehyde level was 3.55 +/- 0.58 nmole/ml in the PGI2 group and 6.35 +/- 1.27 nmole/ml in the control group 60 min after aortic cross-clamp removal (P < 0.05). At the same time interval, protein thiol groups were 629 +/- 50 micromole/L in the PGI2 group and 376 +/- 69 micromole/L in the control group (P < 0.05). Distal arterial pressure and central venous pressure were 15 +/- 4 and 12 +/- 3 mm Hg in the control group and 33 +/- 5 and 7 +/- 1.6 mm Hg in the PGI2 group, respectively (P < 0.05). In this study exogenously administered PGI2 protected the spinal cord from the hazardous effects of aortic occlusion lasting 90 min.

Animals↗
PubMed1996

Comparative study on cardiomyoplasty patients with the cardiomyostimulator on versus off.

BACKGROUND: A major concern in evaluating dynamic cardiomyoplasty has been whether the synchronous stimulation of latissimus dorsi muscle is essential for benefit or not. We studied 10 patients to determine the efficacy of the systolic augmentation generated by the synchronous electrical stimulation of the latissimus dorsi muscle. METHODS: Left ventricular ejection fraction, end-systolic and end-diastolic volume indexes, and stroke volume index obtained during resting, peak exercise, and recovery periods ("on" values) were compared with those obtained 1 week after cessation of electrical stimulus ("off" values). Double product and estimated total body oxygen consumption at peak exercise were also calculated and compared. RESULTS: Higher ejection fractions (0.36 +/- 0.07 versus 0.33 +/- 0.06 at rest, 0.40 +/- 0.07 versus 0.33 +/- 0.07 at peak exercise, and 0.37 +/- 0.06 versus 0.31 +/- 0.06 at recovery).(ABSTRACT TRUNCATED)

Cardiomyoplasty↗
PubMed1996

Long-term results of reconstructions of the left anterior descending coronary artery in diffuse atherosclerotic lesions.

UNLABELLED: One hundred twenty patients who had diffuse atherosclerotic lesions necessitating reconstruction of the left anterior descending artery with or without open endarterectomy and coronary artery bypass grafting were investigated retrospectively and compared with 130 patients who underwent conventional bypass grafting in the same time frame. METHODS: Sixty-one endarterectomies were performed with long arteriotomies (group I) and 59 patch reconstructions were placed over stenosing plaques without an endarterectomy (group II). Patients having only conventional coronary bypass constituted group III. RESULTS: Hospital mortalities were 6.5%, 5.1%, and 1.5% in group I, group II, and group III, respectively (p = not significant). Five patients in group I (8.1%), six in group II (10.1%), and two in group III (1.5%) had perioperative myocardial infarction (group II vs group III, p = 0.016). Angiographic restudy of grafts to the left anterior descending system revealed a patency rate of 81.5% in group I, 79.1% in group II, and 94.4% in group III patients after mean periods of 6.3, 5.7, and 6.1 years, respectively (p = not significant). Actuarial survivals at 7 years were 94% +/- 5.0%, 74.8% +/- 16%, and 90.9% +/- 7.4% in groups I, II, and III, respectively (group I vs group II, p = 0.007; group II vs group III, p = 0.008). Freedom from recurrent angina at 7 years was 42.7% +/- 15.6% in group I, 33.5% +/- 19% in group II, and 71.9% +/- 14.2% in group III (group I vs group III, p = 0.03; group II vs group III, p = 0.0001). Thirty-four percent of patients in group I, 24% in group II, and 60.4% in group III were working actively in the late postoperative period (p = 0.0001). CONCLUSION: Extended revascularizations of the left anterior descending coronary artery increase surgical risk, although not to a statistically significant degree, and should be performed only of necessity. However, once needed, revascularization is a lifesaving procedure with acceptable early and long-term results.

Actuarial Analysis↗
PubMed1996

Enoximone usage for experimental spinal cord protection during aortic cross-clamping.

Spinal cord preservation during aortic cross-clamping is of vital importance. Maintenance of spinal cord blood supply is one of the key points for spinal cord preservation. In this study enoximone was selected as an agent to reduce the risk of spinal cord injury because of its inotropic and vasodilator actions. Ten dogs underwent sixty minutes aortic occlusion. Five animals received enoximone and the others did not (the control group). Enoximone dosage was 10 microgram/kg/min. Four dogs in the control group suffered paraplegia. There were no paraplegic events in the enoximone group. Cerebrospinal fluid pressure was 17 +/- 3 mmHg in the control group, 15 +/- 4 mmHg in the enoxirmone group. Distal aortic pressure was 15 +/- 4 mmHg in the control group, 47 +/- 6 in the enoximone group (p < 0.001). In this study we conclude that enoximone is an effective agent to reduce the risk of spinal cord injury.

Animals↗
PubMed1996

Long term results of mitral valve replacement with preservation of the posterior leaflet.

BACKGROUND AND AIMS OF THE STUDY: It is commonly held that preservation of the annulo-ventricular continuity during mitral valve replacement has a beneficial effect on postoperative ventricular function. This paper presents our eight-year experience with this technique. MATERIALS AND METHODS: From 1986 to December 1992, 120 patients with rheumatic valve disease underwent mitral valve replacement (MVR) combined with preservation of the posterior leaflet of the mitral valve. The mean age was 33.87 years (range 16 to 63). The preoperative New York Heart Association (NYHA) class was III in 64% of the patients and IV in 3%. The early (30 day) mortality rate was 2.5% (3/120). Follow up was 100% complete. The total cumulative follow up was 477 patient-years (pty) with a mean 3.94 years (range: 2-8 years). RESULTS: The actuarial survival rate (including hospital mortality) was 87.6% at eight years. Advanced age (p = 0.0457), increased preoperative functional capacity (p = 0.0251), increased preoperative end-systolic diameter (p = 0.0352) and combined tricuspid reconstruction (p = 0.0001) were found to be independent parameters for a lower actuarial survival rate. Six patients (1.25%/pty) developed thromboembolic complications. Two of these were cerebrovascular accidents (0.41%/pty) and four were caused by mechanical valve thrombosis (1.83%/pty). Freedom from thromboembolic complications (including mechanical valve thrombosis) was 89.8% +/- 7.9%. Fifteen patients (3.14%/pty) developed valve failure, four (0.83%/pty) mechanical valve thrombosis and nine (1.88%/pty) bioprosthetic valve failure. Freedom from reoperation was 60.7% +/- 16.1%. One patient with a St. Jude Medical valve (0.2%/pty) suffered from prosthetic valve endocarditis. Three patients (0.62%/pty) died during the follow up period, and, freedom from all valve related complications was 51.4% +/- 16.1% at eight years. CONCLUSION: Preservation of the posterior leaflet during mitral valve replacement reduces the risk of early mortality and did not cause additional complications to the patients. Despite the beneficial effects of this technique in the long term this technique did not increase the long term survival in patients with associated impaired valvular and/or ventricular function.

Adolescent↗
PubMed1996

Hemodynamic effects of acute intestinal ischemia.

Twelve animals entered in this study with the aim of documenting that superior mesenteric artery small occlusions lasting for one hour have adverse effects on the myocardium. Three hours after cross clamp removal CO decreased to 1.07 +/- 0.11 from 1.99-0.09 a preoperative value (p < 0.01) and PCWP increased to 17 +/- 3 from 8 +/- 3 a preoperative value. MOE reduced to 40-5% 3 hours after cross clamp removal. MLE was -0.21 +/- 0.11 three hours after clamp removal. Changes in MOE and MLE were commented as a defect in myocardial aerobic metabolism. As a result of this study it was concluded that toxic mediators are released from the intestine being reperfused after temporary occlusions of the SMA impair myocardial metabolism, resulting in decreased hemodynamic functions.

Animals↗
PubMed1995

Beneficial effects of prostacyclin treatment on reperfusion of the myocardium.

A total of 20 patients with coronary artery disease were studied in order to assess the benefits of prostacyclin administration on reperfusion of the ischaemic myocardium after cardiopulmonary bypass. Ten received prostacyclin (25 ng/kg per min) while ten were untreated controls. There was no difference between groups with regard to age, preoperative ejection fraction and aortic cross-clamping times. There were no in-hospital deaths in either group. The administration of prostacyclin significantly altered the metabolic side effects of reperfusion followed by hypothermic cardioplegic arrest. Myocardial oxygen consumption after cardiopulmonary bypass was significantly higher in the prostacyclin-treated group than in controls (18.5 ml versus 13 ml; P < 0.01). Prostacyclin treatment significantly reduced the leucocyte activity: leukotriene B4 concentrations were 58 pmol/l in prostacyclin-treated patients compared with 93 pmol/l in controls (P < 0.01). Such recovery of metabolic status during reperfusion resulted in better haemodynamic function in patients receiving prostacyclin.

Coronary Artery Bypass↗
PubMed1995

Routine coronary arteriography before abdominal aortic aneurysm repair.

BACKGROUND: As cardiac complications constitute the principal cause of early and late morbidity and mortality after the surgical treatment of abdominal aortic aneurysm (AAA), a prospective study was planned to evaluate the effects of revascularization of coronary arteries on survival after AAA repair during early and long-term follow-up periods. PATIENTS AND METHODS: A total of 125 patients underwent elective repair of AAA between 1986 and 1994. Coronary arteriography was performed in all cases. All cases with critical left anterior descending artery (LAD) lesions underwent a coronary artery bypass operation either simultaneously or shortly before AAA repair. In addition, percutaneous transluminal coronary angioplasty (PTCA) was performed for symptomatic and critical stenosis of arteries other than the LADs, or if noncritical but symptomatic stenosis of the LADs existed. Early and late follow-up data were obtained for all cases, and late-term cumulative survival rates were calculated. RESULTS: Coronary artery lesions were found in 66 (53%) cases. In 24 cases, AAA repairs were performed 2.3 (mean) months after coronary artery bypass grafting (CABG), whereas in 4 cases both procedures were performed simultaneously. PTCA was performed in 4 cases 3 to 4 days prior to the abdominal surgery. Even though the coronary artery lesions were found inoperable in 7 cases, these patients underwent repair of AAA because of rapidly expanding and painful aneurysms. Early mortality rate was 4% (5 cases), in which 3 of these were from the group inoperable for CABG. A mean follow-up of 3.17 years (3 to 87 months) was achieved for all discharged patients. Cumulative survival rates for 6 months and 1, 2, 3, and 6 years were 99%, 99%, 95%, 93%, and 89%, respectively. CONCLUSIONS: The results of this study emphasize the importance of coronary artery revascularization for early, and especially for late, survival after AAA repair.

Adult↗
PubMed1995

Late results of mitral valve replacement with Carpentier-Edwards high profile bioprosthesis in young adults.

Carpentier-Edwards (C/E) high profile supra-annular porcine bioprostheses were implanted in 163 patients between September 1982-February 1987 in the mitral position due to rheumatic disease. The patients' ages ranged between 15 and 58 years (mean: 36.5 +/- 11.5). One hundred-two of the patients (62.5%) were female. The hospital mortality was 9.8% (16/163). The total cumulative follow-up period was 1093 patient-years (p-y) with a mean of 7.3 +/- 3.5 p-y (range 6 months-12 years). Linearised occurrence rates of the late complications were as follows: Thromboembolism 0.82%/p-v, anticoagulant-related bleeding 1.0%/p-y, prosthetic valve endocarditis 0.09%/p-y. Actuarial survival rates for 5 and 12 years were 87% +/- 6% and 76% +/- 9%, respectively, with 95% confidence limits. Freedom from structural deterioration was 92% +/- 5% for 5 years and 44% +/- 11% for 12 years. Freedom from all valve-related complications was 81% +/- 7 for 5 years and 26% +/- 9 for 12 years. In conclusion, this prosthesis provides satisfactory clinical performance in young population despite the high risk of degeneration with good prognosis and better tolerability of reoperation.

Actuarial Analysis↗
PubMed1995

Risk factors of reoperations for prosthetic heart valve dysfunction in the ten years 1984-1993.

From January 1984 to December 1993 a total of 154 patients (89 men and 85 women) required 160 reoperations for prosthetic heart valve dysfunction. Four patients required a second, two patients a third reoperation. Age was (mean +/- SD [range]) 38.8 +/- 10.2 (17 to 64) years. The primary operation was mitral valve replacement in 105 patients, aortic valve replacement in 20, and both aortic and mitral valve replacement in 29. The time interval between initial valve replacement and reoperation was 66.4 +/- 40 (3 to 288) months for the mechanical prostheses and 68.7 +/- 32 (24 to 140) months for bioprostheses; the difference was not statistically significant. Primary tissue failure was the most common cause of the reoperation for bioprostheses and valve thrombosis for mechanical prostheses. The hospital mortality rate was significantly higher in the replacement of mechanical prostheses (14/58 = 24.1% vs. 7/102 = 6.8%, p = 0.004). Low preoperative functional capacity and valve thrombosis were linked to higher mortality rates. It is discussed that monoleaflet mechanical valves yielded the highest operative mortality and that, excluding these, the risk of mortality in prosthetic valve reoperations today does not differ much from that in primary valve replacements.

Adult↗
PubMed1995

Comparison of the early results of coronary artery bypass grafting with and without extracorporeal circulation.

To compare the safety and efficacy of coronary artery bypass grafting without using extracorporeal circulation with standard cardiopulmonary bypass technique, based on certain early postoperative criteria, we designed a fully randomized and prospective study on two similar groups of 25 patients (off-pump and on-pump groups). The groups were compared for hemodynamic data (cardiac index, systemic vascular resistance, left- and right-ventricular stroke-work indices, inotropic and mechanical support needs) and enzyme levels (CK-MB and SGOT), as well as mortality, perioperative infarction rate, homologous transfusion requirements, and the symptomatology in the first follow-ups. There was no mortality or perioperative myocardial infarction in either group. Inotropic (25% vs. 4%) and mechanical (4% vs. 0) support requirements and homologous blood consumption (percentages of patients that needed no transfusion: 20% vs. 72%) were greater in the on-pump group. Results were otherwise similar. It is concluded that, in technically suitable cases, off-pump coronary artery bypass surgery is as safe and efficient as the standard on-pump technique and can be used in particular when cannulation, hypothermia, or cardiopulmonary bypass must be avoided. With these properties, this technique could take an important place in the cardiac surgeon's armamentarium.

Adult↗
PubMed1995

Cardiomyoplasty.

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Cardiomyoplasty↗