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Biomedical subjects

Kaan Kirali

Publications and source records attributed to Kaan Kirali.

At least 19 recordsLinked to original sources

Multivariate analysis for operative mortality in obstructive prosthetic valve dysfunction due to pannus and thrombus formation.

The objective of the present study was to investigate the risk factors for early hospital mortality in reoperations performed for obstructive prosthetic valve dysfunction. Between January 1994 and April 2005, 63 patients underwent reoperation for obstructive prosthetic valve dysfunction. The mean age of the patients was 40.3 +/- 12.8 years. The mitral valve was replaced in 47 (74.6%) patients, the aortic valve in 6 (9.5%) patients, and both valves in 10 (15.9%) patients. Forty-three (68.2%) patients underwent emergency reoperations. Early hospital mortality occurred in 13 (20.6%) patients. The ethiology of the valve dysfunction was pannus formation in 45 (71.4%) patients and thrombus formation in 18 (28.6%). Pannus and thrombus were localized at the atrial side of the prosthetic valve in 15 (23.9%) patients, at the ventricular side in 13 (20.6%), and at both sides in 35 (55.5%). Inadequate anticoagulation was diagnosed in 28 of 63 (44.4%) patients. The mean INR level in these 28 patients was 1.43 +/- 0.24. In multivariate analysis, the only risk factor for early hospital mortality was left ventricular ejection fraction (P = 0.015; Odds: 0.000, 95% CI: 0.000-0.043). It is concluded reoperations for prosthetic valve dysfunction have a high mortality rate. This study revealed that left ventricular dysfunction is the major determinant of surgical mortality in patients requiring reoperation for valve dysfunction due to pannus or thrombus.

Adolescent↗

Reversed-J inferior sternotomy for awake coronary bypass.

Many approaches for minimally invasive coronary bypass surgery are available and to further decrease the invasiveness, coronary artery bypass grafting has been performed under high thoracic epidural anesthesia without endotracheal intubation in the last years. Less invasive approach to coronary artery bypass graft operations is possible through combination of the high thoracic epidural anesthesia and a reversed-J sternotomy, and coronary revascularization can be accomplished without any additional technical difficulties and with a good exposure of both the left anterior descending artery and the left internal thoracic artery. This technique is less traumatic for patients and provides practical better oxygenation and shorter hospital stay.

Anesthesia, Epidural↗

Melatonin protects against ischemia/reperfusion injury in skeletal muscle.

Melatonin has been shown to diminish ischemia-reperfusion (I/R) injury in many tissues. The main aim of this study was to evaluate the protective antioxidant effect of melatonin in skeletal muscle during I/R injury. Wistar albino rats were randomly divided into three groups. Hindlimb ischemia was achieved by clamping the common femoral artery in two groups but not in control group. Limbs were rendered ischemic for 1.5 hr; at the end of the reperfusion period of 1.5 hr muscle tissue samples were taken for the histological evaluation and biochemical analysis. Melatonin (10 mg/kg) was injected i.p. in the I/R + Mel group at the onset of ischemia whereas the vehicle solution was injected in the I/R group. In I/R + Mel group histological damage was significantly less than in the I/R group (P < 0.001). In the I/R + Mel group, the mean malonedialdehyde level was lower than in the I/R group (P < 0.01) and was quite near to the levels in the control group (P > 0.05). Glutathione levels were found to be reduced in the I/R group compared with the control (P < 0.01) and I/R + Mel group (P < 0.01). Melatonin has a protective effect against I/R injury in skeletal muscle and may reduce the incidence of compartment syndrome, especially after acute or chronic peripheral arterial occlusions.

Animals↗

Effects of giant left atrium on thromboembolism after mitral valve replacement.

The aim of this study was to evaluate the incidence of thromboembolic events in patients with giant left atrium ( > 6.5 cm) after mitral valve replacement. From January 2000 to September 2002, a total of 126 patients who had undergone mitral valve replacement were divided into two groups according to the presence or absence of giant left atrium. Group A comprised 34 patients with left atrium over 6.5 cm without compression symptoms and Group B comprised 92 patients. The preoperative variables did not distinguish the patients in each group, except for atrial fibrillation; Group A 85.2% and Group B 61.9% ( p < 0.01). After mitral valve replacement, left atrium mean diameter was significantly decreased in Group A from 8.1 +/- 1.3 mm to 6.2 +/- 1.6 mm ( p < 0.01). There were no significant differences in thrombosis, hemorrhage and thromboembolism rates in both groups. Postoperative clinical and hemodynamic parameters demonstrated a positive clinical response to mitral valve replacement in patients with giant left atrium. During follow-up no direct relationship between thromboembolism and giant left atrium was evident.

Adolescent↗

Operative mortality after valvular reoperations.

BACKGROUND: To determine the incidence and risk factors of mortality and morbidity in valvular reoperations. METHODS: Between January 1993 and December 2003, 309 valvular reoperations were performed. The reasons for reoperations were reconstructive surgery in first operation (110 patients, 35.5%), prosthetic valve endocarditis (12 patients, 3.8%), periprosthetic leakage (32 patients, 10.3%), new valve degenerations (12 patients, 3.8%), bioprosthetic dysfunction (92 patients, 29.7%), acute thrombotic stuck valve (30 patients, 9.7%), and pannus formation (21 patients, 6.7%). Mitral valves were replaced in 235 patients, aortic valves were replaced in 32 patients, 24 patients had aortic and mitral valve replacements, 2 patients had mitral and tricuspid valve replacements, and reconstruction of periprosthetic leakage was held in 16 patients. 264 patients had elective surgery, whereas 45 were operated on emergency basis. RESULTS: Hospital mortality was 14.23%. Mortality rate was found to be 10.6% for elective cases and 35.5% for emergency cases. Permanent pacemaker was required in 12 patients, 3 patients had cerebrovascular events, and mediastinitis was observed in 1 patient. Multivariate analysis demonstrated that age > 60 (P = .006; OR 7.3, 95% CI 1.7-30.1), emergency surgery (P = .001; OR 8.1, 95% CI 2.4-27.7), preoperative cerebrovascular accident (P = .003; OR 11.8, 95% CI 2.458.7), and concomitant ascending aorta replacement (P < .001; OR 27.4, 95% CI 6-127) were independent risk factors. CONCLUSION: Valvular reoperations can be carried out with acceptable morbidity and mortality in elective operations but mortality rates are still very high in emergent cases.

Adult↗

Composite bilateral internal thoracic artery grafts via standard sternotomy for lateral wall revascularization in conscious patients.

BACKGROUND: A new technique has been developed that permits complete arterial revascularization of the lateral wall of the heart using in situ bilateral internal thoracic artery grafts in awake patients. This technique, performed without cardiopulmonary bypass or mechanical ventilation, creates the least invasive revascularization method for the lateral wall of the heart yet described. METHODS: In 4 patients, double or triple vessel coronary artery bypass grafting was performed without general anesthesia. A high thoracic epidural anesthesia was started 1 hour before surgery. Bilateral internal thoracic arteries were harvested and all anastomoses were performed with the off-pump technique via standard median sternotomy. Circumflex branches were anastomosed with the left internal thoracic artery via a heart positioner. RESULTS: All patients remained awake throughout the whole procedure. There was no perioperative myocardial infarction or mortality. Pneumothorax was observed in only 1 patient and did not hinder the procedure. There were no hemodynamic changes during lateral wall revascularization. Two patients required unexpected coronary endarterectomy during circumflex and right coronary artery anastomoses. CONCLUSIONS: Complete arterial revascularization via median sternotomy using in situ bilateral internal thoracic artery grafts without general anesthesia is a feasible and safe procedure for multivessel disease. This approach allows for complete coronary artery revascularization in patients with contraindications for general anesthesia with or without cardiopulmonary bypass.

Anastomosis, Surgical↗

Using the bilateral internal mammary artery in the left or right coronary artery system: 5-year comparison of operation techniques and angiographic results.

OBJECTIVE: Using the bilateral internal mammary artery (IMA) in coronary artery bypass grafting (CABG) surgery has prolonged survival, improved functional capacity, and reduced the rate of reintervention without increasing postoperative early morbidity and mortality. METHODS: Between January 1996 and December 1997, 94 CABG operations were performed using the bilateral IMA. In Group A (n = 45), the right IMA was anastomosed to the left coronary artery system; in Group B (n = 49), the right IMA was anastomosed to the right coronary artery system. The left IMA was always anastomosed to the left coronary artery system in both groups. RESULTS: There was 1 death (Group A) (1.06%), and 1 late death (Group B) (1.07%). One patient in Group A underwent balloon angioplasty, and 1 patient in Group B underwent reoperation after the follow-up. Pre- and postoperative data were similar between both groups, except for off-pump CABG, which was higher in Group B (2.2% versus 36.7%; P <.001). Twenty-three randomized patients in each group underwent control angiography until May 2002. Angiographic results showed that the patency of the right IMA to the right or left coronary artery system was similar (78.26% versus 82.6%; P = .7). But the left IMA had a better patency rate than the right IMA (95.65% versus 80.43%; P = .02). The patency rates of the left and right IMA anastomosis on the beating heart in Group B were not significantly different (92.3% versus 76.9%; P = .27). The patency of right IMA anastomosis with or without off-pump technique in Group B was similar (76.9% versus 80%; P = .84). CONCLUSIONS: Bilateral IMA can be used with low morbidity and mortality. The angiographic and clinical results of off-pump CABG show that bilateral IMA can also be used in off-pump surgery with similar results.

Adult↗

[Cardiovascular manifestations and treatment in Marfan syndrome].

Marfan syndrome is a dominantly inherited connective tissue disease characterized by cardiovascular, skeletal and ocular manifestations, which was firstly described by Antoine Marfan in 1896. The underlying disorder is a mutation, which impairs fibrillin synthesis and is associated with the FBN-1 gene on the 15th chromosome. Ghent Nosology is used for diagnosis. The progressive dilatation of the proximal aorta leading to dissection and rupture is the typical feature of the disease. Aortic aneurysm and aortic rupture are the lethal complications of the disorder. Increased life expectancy depends on the control and the prevention of the cardiovascular complications. The most frequent cardiovascular manifestation is the mitral valve involvement. The principal pathologic findings on the mitral valve are annular dilatation, fibromyxomatous changes of the leaflets and chordae, elongation and rupture of chordae and deposition of calcium. Prolapsus occurs in 80% of the cases. Elective surgery with optimal timing is associated with increased survival. In the follow-up of patients after surgery for aortic aneurysm and dissection, serial imaging studies in order to detect a new onset aneurysm or dissection on different sites of the aorta are essential.

Cardiovascular Diseases↗

Comparative PRKAR1A genotype-phenotype analyses in humans with Carney complex and prkar1a haploinsufficient mice.

Carney complex (CNC) is a familial multiple neoplasia syndrome characterized by cardiac and extracardiac myxomas in the setting of spotty skin pigmentation and endocrinopathy. We previously identified PRKAR1A (regulatory subunit 1alpha of protein kinase A) mutations in CNC. Mutational analyses of the PRKAR1A gene in 51 unrelated CNC probands now detect mutations in 65%. All mutations, except for one unique missense mutation, lead to PRKAR1A haploinsufficiency. Therefore, we studied the consequences of prkar1a haploinsufficiency in mice. Although we did not observe cardiac myxomas or altered pigmentation in prkar1a(+/-) mice, we did observe some phenotypes similar to CNC, including altered heart rate variability. Moreover, prkar1a(+/-) mice exhibited a marked propensity for extracardiac tumorigenesis. They developed sarcomas and hepatocellular carcinomas. Sarcomas were frequently associated with myxomatous differentiation. Tumors from prkar1a(+/-) mice did not exhibit prkar1a loss of heterozygosity. Thus, we conclude that although PRKAR1A haploinsufficiency does predispose to tumorigenesis, distinct secondary genetic events are required for tumor formation.

Alleles↗

Midterm results of aortic valve repair with the pericardial cusp extension technique in rheumatic valve disease.

BACKGROUND: The encouraging results of valve repair in the atrioventricular valves have influenced a decision about aortic valve (AV) reconstruction. We report our experience with pericardial cusp extension to repair rheumatic AV disease. METHODS: From 1993 to 1998, 46 patients (25 women, 21 men) with a mean age of 31.5 +/- 12.2 years (range, 15 to 58 years) underwent AV repair. Twenty-two (47.8%) patients had moderate and 24 (52.2%) had severe aortic insufficiency (AI). Severe cusp retraction was repaired with glutaraldehyde-treated autologous pericardium. Twenty-one patients had more than one maneuver (mean, 1.8) to attain competence besides augmentation, which consisted of the release of stenotic commissures (in 11 cases), thinning of the AV cusps (in 10 cases), and resuspension of the cusps (in 17 cases). Simultaneous mitral valve repair was performed on 17 patients. Eight patients received triple valve reconstruction. RESULTS: There was no early mortality. Thirty patients no longer had AI with any significant transvalvular gradients. Five patients were followed with mild residual AI, and 2 patients with moderate AI not requiring reoperation. Nine patients developing severe AI required AV replacement with a reoperation rate 19.6% (4.26%/patient-year). The mean interval between repair and reoperation was 28.2 +/- 18.3 months (range, 3 to 58 months). The mean observation time was 4.6 +/- 3 years (211.6 patient-years). Late mortality rate was 2.2% with 1 patient. The significant negative predictors of aortic reoperation determined by univariate analysis were preoperative New York Heart Association class (p = 0.002) and postoperative severe AI (p < 0.001). Cox hazard studies identified that all risk factors were insignificant for aortic reoperation. The actuarial rate of freedom from aortic reoperation was 76.1% +/- 7% at 7.5 years. CONCLUSIONS: Although AV repair by extension with pericardium is worth considering with an acceptable solution to achieve a good geometry from unequal cusps, especially in young rheumatic patients for preservation of the native AV, the patients should be followed periodically for reoperation risk.

Adolescent↗

Off-pump awake coronary revascularization using bilateral internal thoracic arteries.

BACKGROUND: A new technique has been developed that permits complete arterial revascularization of the lateral and/or inferior wall of the heart using in situ bilateral internal thoracic artery grafts in awake patients. This technique, without cardiopulmonary bypass and mechanical ventilation, creates the least invasive revascularization method for the lateral and/or posterior wall of the heart yet described. METHODS: In 7 patients double or triple vessel coronary artery bypass grafting was performed without general anesthesia. A high thoracic epidural anesthesia was started one hour before surgery. Bilateral internal thoracic arteries were harvested and all anastomoses were performed with the off-pump technique by standard median sternotomy. Circumflex, or the right coronary artery, were anastomosed with bilateral internal thoracic arteries using a heart positioner. Six patients received double bypass grafting and one patient received triple bypass grafts (bilateral internal thoracic arteries and one radial artery). RESULTS: All patients remained awake throughout the whole procedure. There was no perioperative myocardial infarction or mortality. Pneumothorax was observed in three patients, but it was repaired in two. Only one patient completed the procedure with unilateral pneumothorax. There were no hemodynamic and pulmonary problems during lateral or posterior wall revascularization. Two patients required unexpected coronary endarterectomy during circumflex and right coronary artery anastomoses. CONCLUSIONS: Complete arterial revascularization by median sternotomy using in situ bilateral internal thoracic artery grafts without general anesthesia is a feasible and safe procedure for multivessel disease. This approach gives a chance for awake revascularization of the right and/or circumflex coronary artery.

Adult↗

Partial cardiac autotransplantation for reduction of the left atrium.

Various surgical procedures have been employed to treat a greatly enlarged left atrium. We review the use of partial cardiac autotransplantation to reduce left atrial volume in 7 patients with rheumatic mitral valve disease and left atrial and ventricular volume in 2 patients with idiopathic dilated cardiomyopathy. There were 5 males and 4 females aged 25 to 62 years. The patients with rheumatic etiology had atrial fibrillation, while those with dilated cardiomyopathy had sinus rhythm. The mitral valve was replaced in 6 patients and reconstructed in 3. Mean aortic cross clamp time in the operations involving isolated left atrial resection was 119 +/- 44 min. Mean left atrial volume fell from 331 mL to 92 mL, while mean left atrial diameter decreased from 8.6 cm to 4.7 cm. Sinus rhythm was restored in 5 of the 7 patients who had preoperative atrial fibrillation. There was no operative mortality. The patients with dilated cardiomyopathy died in the postoperative period, one on the 14th day from low cardiac output and the other on the 113th day from multiorgan failure. Partial cardiac autotransplantation can be effective in reducing heart chamber size in selected patients, especially those with giant left atrium.

Adult↗

Evolution of repaired and non-repaired tricuspid regurgitation in rheumatic mitral valve surgery without severe pulmonary hypertension.

The aim of this study was to evaluate the usefulness of repairing significant tricuspid regurgitation (> or = grade 2) without severe pulmonary hypertension (< or = 50 mm Hg). Between 1993 and June 2001, 88 consecutive patients were operated on for rheumatic mitral valve disease associated with significant tricuspid regurgitation and without severe pulmonary hypertension. The severity of the tricuspid valve disease was assessed by echocardiography. Sixty-three patients had severe (> or = grade 3) tricuspid regurgitation (Group I), and 25 patients had moderate (grade 2) tricuspid regurgitation (Group II). There was no hospital mortality. six patients died during follow-up. The overall actuarial survival rate for 8 years was 92.1% +/- 3.1%. Cox proportional hazard regression analysis showed that age ( p = 0.006) and pulmonary complication ( p = 0.01) were associated with increased late mortality. Freedom from death was similar in both groups at 8 years (93.1% +/- 3.3% versus 88% +/- 8%, p = 0.7). Severe postoperative tricuspid regurgitation (> or = grade 3), caused by the failure of tricuspid repair or leaving the valve untouched, impaired long-term survival after surgery, and actuarial survival was 96.1% +/- 2.7% and 83% +/- 7.8% at 7 years ( p = 0.048), respectively. Severe tricuspid regurgitation, functional or organic, should be corrected at the time of mitral valve surgery, whereas untouched functional moderate tricuspid regurgitation improves after mitral valve surgery.

Adult↗

Combined coronary artery bypass grafting and lung surgery.

Combined coronary bypass and lung surgery was performed in 3 patients. Through a median sternotomy or a left thoracotomy, bypass grafting was performed on beating heart or under cardiopulmonary bypass, followed by the lung operation. The lung lesion was diagnosed as carcinoma in 2 patients and hydatid cyst in 1 patient. With few exceptions, beating heart coronary bypass through a median sternotomy can be performed in a combined operation.

Aged↗

Surgical outcome of subtypes of aortic arch dissection.

This study was conducted to investigate if the site of primary intimal tear involving the aortic arch and the surgical approach affect the early and late results of total aortic arch replacement. Between 1993 and November 2001, 42 patients underwent graft replacement of the total aortic arch for aortic dissection. Their mean age was 51.9 +/- 9.8 years, and 38 of them were male. All operations were performed under hypothermic circulatory arrest with retrograde cerebral perfusion. Hospital mortality was 28.6% (12 patients). There were 2 late deaths. Multivariate analysis showed that chronic obstructive pulmonary disease and ascending aortic replacement with or without valve replacement were significant independent determinants of early death. Patients with the intimal tear originating in the ascending aorta showed a tendency towards lower 7-year survival rates than those with a tear at other aortic sites or with multiple tears, while the presence of chronic obstructive pulmonary disease adversely affected early and late outcomes. We conclude that the primary site of an intimal tear that involves the aortic arch affects early and late survival, but concomitant non-cardiac diseases play an even more important role in the early outcome as they increase the complexity of the operation.

Adult↗

[Surgical treatment of iatrogenic cardiac traumas induced by heart catheterization].

BACKGROUND: A retrospective evaluation was made on iatrogenic cardiac traumas requiring surgical treatment, that were induced by cardiac catheterizations and interventions performed within a 17-year period. METHODS: A total of 64,911 patients underwent cardiac catheterizations and interventions from 1985 to 2002. Complications of iatrogenic cardiac traumas induced by these interventions were examined together with the surgical treatment performed within 24 hours after catheterization. RESULTS: Iatrogenic cardiac trauma requiring prompt surgical intervention was documented in 20 patients (6 females, 14 males; mean age 51 years; range 31 to 69 years). These were due to coronary angiography/balloon angioplasty-stenting in 14 (70%), percutaneous mitral balloon valvuloplasty in four (20%), and to heart catheterization in two patients (10%). Acute cardiac tamponade was detected in 10 patients (50%) resulting from perforations to the cardiac chambers in six, coronary arteries in two, and major vessels in two patients. Surgical interventions included coronary artery by-pass in 14, mitral valve surgery in four, and repair of major vessels in two patients. Perioperative mortality occurred in two patients. Six patients developed complications contributing to morbidity, including perioperative myocardial infarction (3 patients), infection (2 patients), and prolonged intubation (1 patient). CONCLUSION: In case of major cardiac complications induced during cardiac catheterizations, early diagnosis and prompt surgical intervention are of vital importance regardless of considerably high risks.

Adult↗

[Traumatic vascular complications due to intraaortic balloon pump support].

BACKGROUND: The use of an intraaortic balloon pump (IABP) catheter was retrospectively evaluated in terms of risk factors, insertion techniques, and complications in patients with low cardiac output. METHODS: A total of 1036 patients (804 males, 232 females; mean age 53.4 years; range 16 to 75 years) received IABP support from 1985 to March 2002. Of these, 789 patients (76.1%) underwent open heart surgery, 247 patients (23.8%) developed low cardiac output during medical treatment. Insertion of IABP was performed via the femoral artery either percutaneously by the Seldinger technique in 897 patients (86.6%), or by direct surgical exposure in 88 patients (8.5%). Open surgical IABP insertion was performed through an 8 mm Dacron graft placed with an end-to-side anastomosis to the common femoral artery (88 patients) or to the ascending aorta (23 patients). RESULTS: The overall mortality rate was 35.1% (364 patients). Vascular complications were associated with IABP in 104 patients (10%), of which 57 patients (5.5%) required surgical treatment. Major complications were aortic arch dissection in two patients and paraplegia in two patients. Vascular complications tended to increase with female gender, older age, diabetes, and peripheral vascular disease. The mean duration of IABP support in the presence of vascular complications was 7.8 days (range 5 hours to 77 days). CONCLUSION: Application of unsheathed IABP and proper evaluation of peripheral circulation seem to decrease the incidence of vascular complications.

Adolescent↗