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K Bayazit

Publications and source records attributed to K Bayazit.

At least 19 recordsLinked to original sources
PubMed1999

Minimally invasive mitral valve surgery: the subxiphoid approach.

BACKGROUND: This report describes mitral valve replacement using a unique subxiphoid approach with a lower ministernotomy and a skin crease incision and compares the operative and echocardiographic results to patients undergoing mitral valve replacements using previously described strategies. METHODS: Fifty-four patients underwent mitral valve replacement using a subxiphoid approach (group 1); 32 patients underwent mitral valve replacement, 11 patients underwent mitral valve replacement + tricuspid reconstruction, 2 patients underwent mitral valve replacement + tricuspid valve replacement, and 9 patients underwent mitral reconstruction. This group of patients was compared to 11 patients who underwent mitral valve replacement through a superior ministernotomy (group 2) and 29 patients who underwent mitral valve replacement with full median sternotomy (group 3, 22 mitral valve replacements, 2 mitral valve replacements + tricuspid reconstruction, 2 mitral reconstructions, and 3 mitral reconstructions + tricuspid reconstruction). RESULTS: There was no operative mortality in all groups. The operation lasted significantly longer in group 2 patients compared to group 1 and 3 patients (p < 0.01). Postoperative mediastinal drainage was significantly lower in groups 1 and 2 (p < 0.001). Pain assessment revealed no difference between the groups. Three patients in group 1 presented with pericardial effusion. Except for this complication, early postoperative echocardiographic findings of the patients were similar in all three groups. All patients were in New York Heart Association functional class I or II at the second postoperative month, irrespective of the surgical technique used. CONCLUSIONS: There was no prominent superiority of the ministernotomy approaches over the standard median sternotomy approach. However, the reliability of the subxiphoid approach is documented echocardiographically and any type of mitral replacement can be performed with this approach.

Adult↗
PubMed1999

Carotid disease in patients scheduled for coronary artery bypass: analysis of 678 patients.

The purpose of this article is to investigate the frequency of carotid disease and to identify high-risk groups among patients scheduled for isolated coronary artery bypass grafting (CABG) procedures under nonemergent conditions. A total of 678 consecutive patients underwent preoperative carotid artery duplex scanning (CADS) before CABG procedures. Morphology of carotid artery was determined and five groups were formed. Age, sex, cervical bruit, diabetes mellitus (DM), hypertension, smoking, history of cerebrovascular event (CVE), peripheral vascular disease (PVD), and severity of coronary artery disease were investigated to describe the high-risk group for carotid artery disease. In 41% of patients carotid examination produced normal findings; 46.2% had less than 60% luminal stenoses, 7.1% had 60-79% stenoses, 4.6% had 80-99% stenoses, and 1.2% had total occlusion. Previous cerebral ischemic events (CVE) (p<0.05), hypertension (p < 0.01), smoking (p < 0.01), advanced age (p < 0.01), and female sex (p < 0.01) were identified as high-risk factors for carotid artery stenoses. There was a linear association between carotid disease and coronary disease (p < 0.05). Documentation of previous CVE, hypertension, smoking, advanced age, female sex, and severe coronary artery disease may be helpful in identifying patients at high risk for carotid artery stenoses.

Adult↗
PubMed1998

Optimization of synchronization delay in latissimus dorsi dynamic cardiomyoplasty.

BACKGROUND: Optimal synchronization delay (SD) for triggering the implanted cardiomyostimulators in patients undergoing latissimus dorsi dynamic cardiomyoplasty has not been clearly defined. Generally a synchronization delay time of 45 to 60 ms is used in the current practice, in which the implanted cardiomyostimulator stimulates the latissimus dorsi muscle 45 to 60 ms after mitral valve closure acquired with M-mode echocardiography. We investigated the effect of shortening or prolonging the delay time on cardiac functions. METHODS: We studied 10 patients who were in their first 2 years postoperatively. Three values for SD (SD = 0 ms, 45 to 60 ms, and 150 to 160 ms) were echocardiographically evaluated for their influence on both systolic and diastolic left ventricular parameters. RESULTS: Ejection fractions were 0.27 +/- 0.07, 0.28 +/- 0.07, and 0.32 +/- 0.06; peak aortic velocities were 0.85 +/- 0.8, 0.86 +/- 0.11, and 0.92 +/- 0.8 m/s; and velocity-time integrals were 0.16 +/- 0.03, 0.16 +/- 0.03, and 0.19 +/- 0.03 m for the SD values of 0, 45 to 60 ms, and 150 to 160 ms, respectively. Diastolic parameters were also measured. Isovolumetric diastolic relaxation time was 97.5 +/- 49, 97.20 +/- 44, and 111.8 +/- 49 ms; deceleration time was 83.67 +/- 32, 88.48 +/- 35, and 92.68 +/- 34 ms; and ratio or velocity-time integral of e wave to velocity-time integral of a wave was 3.09 +/- 0.98, 2.48 +/- 0.69, and 2.38 +/- 0.65 for the SD values of 0, 45 to 60 ms, and 150 to 160 ms, respectively. Systolic functions were better when SD was set at 150 to 160 ms, but there was a diastolic compromise. On the other hand, diastolic parameters were more favorable when SD = 0 (i.e., cardiomyostimulator triggered without delay) but the systolic assist was suboptimal. Systolic and diastolic parameters seemed relatively well-balanced with the current practice of setting the synchronization delay at 45 to 60 ms. CONCLUSIONS: The most favorable systolic effects were obtained with a prolonged delay of synchronization (150 to 160 ms), at some expense of diastolic functions. On the other hand, with a short or absent delay, diastolic parameters were improved but systolic parameters became suboptimal. Therefore, the current practice of setting the SD between 45 and 60 ms after echocardiographic mitral valve closure is suggested for the optimal timing for cardiomyostimulator stimulation in patients who have undergone latissimus dorsi dynamic cardiomyoplasty. Yet a great deal of individualization is necessary, and fixed preset values cannot definitely be determined because one setting does not fit all patients.

Aorta↗
PubMed1998

Coronary artery bypass grafting on the beating heart without the use of extracorporeal circulation: review of 2052 cases.

OBJECTIVE: A total of 2052 patients operated on with the off-pump technique (coronary artery bypass grafting on the beating heart without the use of extracorporeal circulation) between June 1993 and March 1996 are retrospectively reviewed. Predictors for early mortality, perioperative myocardial infarction, and low cardiac output state were statistically analyzed. METHOD: Our indications for an off-pump procedure were either patients with technically suitable coronary lesions (the vast majority) or patients who could not tolerate cannulation, hypothermia, or cardiopulmonary bypass because of the poor left ventricular function (198 patients) and/or associated diseases or conditions (73 patients). RESULTS: Overall operative mortality was 1.9% and perioperative myocardial infarction occurred in 59 patients (2.9%). According to logistic regression analysis, associated bronchial asthma (p = 0.0001), hypertension (p = 0.05), poor quality of the left anterior descending artery (p = 0.02), and ungrafted circumflex coronary artery disease (p = 0.007) were the early mortality predictors. Nonbypassed circumflex disease was also associated with a high incidence of perioperative myocardial infarction and low cardiac output state. No homologous blood or packed red cell transfusion was required in 74.2% of the patients. CONCLUSION: On the basis of the presented data, off-pump coronary artery bypass grafting appeared to be a safe and effective technique in selected patients with appropriate coronary lesions.

Adult↗
PubMed1998

Left ventricular aneurysm repair: an assessment of surgical treatment modalities.

OBJECTIVE: Different closure techniques (linear vs. circular), as well as the efficacy of revascularization in the left ventricular aneurysm repair, with regard to immediate and mid-term results, were assessed and factors having influence on the early mortality and morbidity and survival were analyzed. METHOD: Between January 1991 and November 1996, 248 patients underwent surgical repair for postischemic left ventricular aneurysm. A total of 26 of them were female (10.50%). Linear closure was employed in 121 patients (48.8 %) and circular (patch endoaneurysmorraphy) closure in 127 (51.2%). Coronary revascularization was added in 203 (81.9%) cases. Patients were followed for an average follow-up time of 39.3 months. RESULTS: Early mortality rate was 6% (15 patients). The difference in mortality rate by the repair method was not statistically significant (8.3% in the linear closure group and 3.9% in the circular closure group, P = 0.15). Absence of preoperative angina pectoris (P = 0.029), dyspnea as the presenting symptom, a preoperative left ventricular segmental wall motion scoring of 14 or greater, a cardiopulmonary bypass duration exceeding 2 h (P = 0.004), an aortic clamping time exceeding 1 h (P = 0.026) were associated with early mortality. Concomitant coronary revascularization had no effect on early mortality. However, low cardiac output state was less frequent in patients with concomitant coronary revascularization (P = 0.022). Functional status improved in both groups. Follow-up extending to 81st month revealed no difference in survival between the groups (84% for linear closure group and 92% in circular closure group, including operative mortality, P = 0.12). However, functional status improvement was better in the patients who underwent circular repair (P = 0.0077). Revascularization appeared as having no important influence on both survival and functional status. A preoperative left ventricular segmental wall motion scoring of 14 or greater was associated with a higher incidence of early mortality, low cardiac output syndrome and poor long-term survival. CONCLUSION: Left ventricular aneurysm repair is an important therapeutic intervention and can be performed with reliable results, regardless of repair method, either linear or circular. Long term results revealed better functional status in circular repair group. Concomitant coronary revascularization reduced the incidence of low cardiac output state. Performance of the unaffected regions of myocardium was found to be an important determinant of both early and late outcome.

Adolescent↗
PubMed1998

Bloodstream, respiratory, and deep surgical wound infections after open heart surgery.

Nosocomial infections are one of the most feared complications after open heart surgery. A large retrospective study was conducted to evaluate the nature and scope of the problem. Between 1992 and 1998, 9352 patients who had undergone open heart surgery were evaluated. Bloodstream infections, pneumonia, and deep sternal wound infections were included. Univariate and logistic regression analyses were conducted to identify the high-risk patients that were likely to become infected. Three hundred forty-six infections in 276 patients were diagnosed. Age, preoperative albumin level, banked blood requirement, duration of operation, diabetes mellitus, previous open heart surgery, moderate or severe pericardial adhesions, obesity, postoperative low cardiac output, and postoperative cerebrovascular accident were found to be significant in univariate and logistic regression analyses for infectious outcome. Univariate analysis also revealed additional significant factors: fresh frozen plasma requirement, duration of cardiopulmonary bypass and cross-clamp, preoperative high levels of blood urea and glucose, presence of occlusive peripheral arterial disease, preoperative history of hypertension, and nasal carriage of Staphylococcus aureus. Methicillin resistant S. aureus was involved in 58.4% of the infections. Risk factors should be individualized for patients and every effort should be carried out to minimize infectious outcome.

Adolescent↗
PubMed1998

Mitral valve replacement with St. Jude Medical prosthesis and low-dose anticoagulation in patients aged over 50 years.

BACKGROUND AND AIMS OF THE STUDY: These studies were designed to assess the effect of low-dose anticoagulation in elderly patients after mitral valve replacement. METHODS: Between 1986 and 1995, 250 patients aged > or = 50 years underwent isolated mitral valve replacement at the Cardiovascular Surgery Clinic of Turkiye Yuksek Ihtisas Hospital. The overall hospital mortality rate was 8%. Postoperatively, all patients received 2.5 mg/day warfarin, and 225 mg/day dypridamole and 250 mg/day aspirin following removal of mediastinal tubes. This regimen was continued indefinitely thereafter. RESULTS: Postoperatively, the mean International Normalized Ratio (INR) was 1.4 +/- 0.67 (range: 0.9 to 4.19) and mean prothrombin time 13.33 +/- 1.98 min (range: 11.7 to 21.3 min). Mean follow up was 1.42 +/- 1.2 years (range: 2 months to 8.3 years); total cumulative follow up was 322.75 patient-years (pt-yr). During follow up, six patients (1.85% per pt-yr) developed thromboembolic complications (including mechanical valve thrombosis), two (0.62% per pt-yr) developed oral anticoagulant-related bleeding, and two (0.62% per pt-yr) developed paravalvular leak. Five patients died during follow up (late mortality rate 1.2% per pt-yr). The nine-year actuarial survival rate was 93.9 +/- 4.8% for the entire group. CONCLUSIONS: Low-dose oral anticoagulation after mitral valve replacement with St. Jude Medical prosthesis in elderly patients provided satisfactory clinical results.

Actuarial Analysis↗
PubMed1997

Septal myectomy in hypertrophic obstructive cardiomyopathy: late results with stress echocardiography.

BACKGROUND: This study was performed to assess the functional capacity of the survivors of septal myectomy for the treatment of hypertrophic obstructive cardiomyopathy in long-term follow-up as assessed by dobutamine stress echocardiography. METHODS: Sixty-nine patients with hypertrophic obstructive cardiomyopathy underwent septal myectomy between 1975 and 1996. The mean age was 25.4 +/- 13.6 years (range, 6-58 years), and 10 of the patients were women. The early mortality was 4.3%. Hospital survivors (95.7%) were followed up for a mean of 43.8 +/- 28.7 months (range, 6-114 months). RESULTS: The postoperative mean functional capacity of the group was 1.47 +/- 0.56. No late deaths were reported. Forty-nine patients (74.2%) were evaluated with standard echocardiographic techniques, and 29 (43.9%) patients underwent dobutamine stress echocardiography. There was a significant decrease in the thickness of the interventricular septum after surgery. The mean preoperative and postoperative septal thickness was 1.99 +/- 0.59 cm (range, 1.3-3.8 cm) and 1.55 +/- 0.41 cm (range, 0.96-2.8 cm), respectively (p < 0.004). The mean posterior wall thickness was significantly less than the preoperative value (p = 0.008) and the left ventricular end-diastolic diameter was slightly greater in the postoperative measurements, but the difference was not significant (p = 0.162). Postoperative left ventricular outflow systolic gradients were reduced significantly when compared with preoperative values (preoperative mean, 78.4 +/- 33.6 mm Hg, range, 50-212 mm Hg versus postoperative mean, 17.9 +/- 15.9 mm Hg: range, 0-40 mm Hg; p < 0.0001). CONCLUSION: Septal myectomy for patients with hypertrophic obstructive cardiomyopathy is a safe procedure with excellent clinical and functional results in the long-term follow-up.

Actuarial Analysis↗
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↗