Biomedical subjects
Publications and source records attributed to M Ozbaran.
Ectopic localisation of the pancreas is not an uncommon entity, but it is mostly seen in the gastrointestinal tract. Herein we report a 45-year-old woman with a cyst containing pancreatic tissue in the mediastinum. The English literature reveals only three previous cases of this extremely rare localisation of the pancreas.
Acute infective endocarditis affecting the aortic root and valve associated with development of a fistulous communication between the aorta and pulmonary artery was presented in a young Turkish girl. Emergency surgery was required. Operation consisted initially of closure of the defect on the main pulmonary artery with a pericardial patch. This was followed by allograft aortic root replacement.
BACKGROUND: Desmopressin acetate (DDAVP) has been implicated as a promising agent to reduce blood loss in patients undergoing cardiopulmonary bypass. METHODS: The effects of intraoperative desmopressin were studied in 66 patients undergoing coronary artery bypass grafting, randomized equally into desmopressin and control groups. The desmopressin group received 0.3 microg/kg desmopressin at the end of cardiopulmonary bypass. RESULTS: Fibrinogen level of both groups significantly reduced at postoperative 2nd hr, whereas a significant rise was observed at postoperative 24th hr with an intergroup difference favoring the control group (p=0.0307). In the desmopressin group, the activation time of factor VIII shortened during the whole postoperative period being significant (p=0.0127) at postoperative 24th hr. Postoperative von Willebrand factor (vWF) levels of the desmopressin group were significantly higher than the preoperative ones. The control group did not show such important changes in factor VIII and vWF measurements. Platelet aggregation times of both groups prolonged at postoperative 2nd hr. The control group showed significant elevation in ADP induced aggregation time at 2nd hr and significant reductions of platelet activation percentage in response to ADP, epinephrine, collagen and ristocetin at 2nd hr. Postoperative blood loss as well as blood transfusion need did not differ between the two groups. CONCLUSIONS: Despite the improved platelet functions, desmopressin does not seem to have obvious beneficial effects on postoperative hemostasis in patients without any bleeding disorder and undergoing elective cardiac surgery.
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BACKGROUND AND AIM OF THE STUDY: The study aim was to examine comparatively the effects of prosthetic and homograft valves in the aortic position on ventricular hemodynamics and structure. METHODS: Hemodynamic evaluations were performed at rest and during exercise in 38 patients who had undergone aortic valve replacement (AVR) with either a homograft (n = 19) or prosthetic valve (19-23 mm; n = 19). Using echocardiographic, electrocardiographic and hematologic methods, the pressure gradient (PG); aortic valve area; diameters of left anterior wall, posterior wall (PW) and interventricular septum (IVS); ejection fraction (EF); left ventricular mass (LVM) and mass index (LVMI); electrocardiographic data of LV hypertrophy; hemoglobin; hematocrit and lactate dehydrogenase (LDH) levels were measured. RESULTS: LVM and LVMI decreased significantly after surgery in both groups (p<0.001), but the decrease was significantly greater in the homograft group (p<0.05). The IVS and PW diameters in the homograft group decreased significantly postoperatively (p<0.05); the inter-group difference was also significant (p<0.01). In the homograft group there was a significant improvement in EF (p<0.05), and the exercise PG was significantly less. Both groups showed improved LV hypertrophy and correlation between V1S >24 mm criteria and LVMI measurements. Postoperative LDH levels in the homograft group were significantly lower than preoperative levels (p<0.05); the intergroup difference was also significant (p<0.001). CONCLUSIONS: Our data suggest that homografts, as compared to mechanical prostheses, provide significantly better hemodynamics in the aortic position.
OBJECTIVE: Renal failure is known to increase the morbidity and mortality in patients undergoing cardiac surgery. The results of heart surgery in patients with non-dialysis-dependent, mild renal insufficiency are not clear. METHODS: One hundred nineteen adult patients with chronic renal failure underwent cardiac surgery. Group I consisted of 93 patients who had creatinine levels between 1.6 and 2.5 mg/dL but who were not supported by dialysis. Group II consisted of 18 patients with creatinine levels higher than 2.5 mg/dL who were not supported by dialysis. Group III consisted of 8 patients with end-stage renal disease who were receiving hemodialysis. RESULTS: The hospital mortality rates were 11.8%, 33.0%, and 12.5%, respectively. Morbidity was 21.5%, 44.4%, and 75.0%, respectively, in groups I, II, and III. Postoperative hemodialysis was needed in 2 (2.15%) patients from group I and 6 (33%) patients from group II. On multivariable logistic regression analysis, risk factors for mortality were preoperative creatinine level more than 2.5 mg/dL, angina class III-IV, emergency operation, excessive mediastinal hemorrhage, postoperative pulmonary insufficiency, low cardiac output, and rhythm disturbances. Risk factors for morbidity were preoperative creatinine level more than 2.5 mg/dL and postoperative dialysis. CONCLUSIONS: Chronic renal failure increases the mortality and morbidity in patients undergoing cardiac surgery. Renal insufficiency with creatinine levels higher than 2.5 mg/dL increases the risk of postoperative dialysis and prolongs the length of hospital stay. Careful preoperative management and intraoperative techniques, such as avoiding low perfusion pressure and using low-dose dopamine, may be useful for a good operative outcome.
Coronary arteriosclerosis seriously complicates the surgical treatment of aortic diseases. The aim of our retrospective study was to determine the incidence of coronary artery disease among our surgical patients in treatment for aortic dissection or aneurysm, and to determine whether coronary intervention before aortic surgery appears to affect outcomes. Between 1 January 1993 and 1 March 1998, our center treated 253 patients for aortic dissection or aneurysm. We examined these cases retrospectively for information on diagnostic and treatment methods, both for the aortic lesions and for concomitant coronary arteriosclerosis. Aortic dissection had been detected in 86 (33.9%) patients and aortic aneurysm in 167 (66.1%). Coronary angiography was performed to search for concomitant coronary artery disease in 29 (33.8%) patients with dissection and in 112 (67.1%) patients with aneurysm; of these, 11 (12. 7%) and 54 (32.3%), respectively, were found to have coronary disease. Among 43 patients with abdominal aortic aneurysm in whom coronary angiography was performed, concomitant coronary disease was detected in 36 (83.7%). Coronary artery bypass surgery was performed in 10 patients who had dissection and in 30 patients who had aneurysm; percutaneous transluminal coronary angioplasty was performed in 7 patients who had aneurysm. Perioperative mortality rates in the dissection and aneurysm groups, overall, were 23.2% and 13.8%, respectively Unfortunately, the prospective, random clinical study that would be necessary to prove the case for or against preoperative coronary angiography among subsets of patients in need of aortic repair would raise ethical questions, given the strength of the information already in our possession, gathered by less formal methods. Our study reinforces existing evidence that preoperative angiography can reduce mortality and morbidity in the elective repair of aortic aneurysm, especially thoracic or abdominal aneurysm. However, angiography should not be performed routinely in cases of aortic dissection and should be withheld in cases of type A dissection.
Heparin attachment to synthetic surfaces is one means of improving the biocompatibility of clinically used cardiopulmonary bypass (CPB) circuits. To assess the effect of heparin-coated circuits on complement consumption during CPB, 40 patients undergoing elective myocardial revascularization were prospectively randomized either to a group in which a completely Duraflo II heparin-coated circuit was used for perfusion (heparin-coated Group, n = 20 patients) or to a control group (n = 20 patients) in which an uncoated, but otherwise standard circuit was used. Full systemic heparinization was induced (activated clotting time, 480 seconds) in all the patients included in the study, regardless of which perfusion circuit was used. The two groups did not differ significantly in terms of bodyweight, aortic crossclamp and extracorporeal circulation times. No patient had difficulty in weaning from bypass and the postoperative period was uneventful in all patients. Concentrations of C3 and C4 were found to be within the "normal' range in the prebypass period in both groups. There were no significant intergroup differences with regard to C3 and C4 consumption during CPB. We conclude that Duraflo II heparin-coated circuits have no effect in reducing complement consumption during CPB in fully heparinized patients.
We reviewed the cases of 69 consecutive patients who underwent physiologic reconstruction of the left ventricular cavity with an endoventricular patch (endoaneurysmorrhaphy) after aneurysmectomy. Eight patients had isolated endoaneurysmorrhaphy, 60 patients had concomitant coronary artery bypass grafting, and 1 patient had concomitant closure of an atrial septal defect. The primary indications for operation were angina pectoris (New York Heart Association functional class I or II) in 42 patients and dyspnea (functional class III or IV) in 27 patients. The preoperative left ventricular ejection fraction evaluated with ventriculography was 28.95% +/- 7.27% (mean +/- standard error of the mean). The global perioperative mortality rate was 2.8%. Total follow-up was 139.3 patient-years. The late mortality rate was 4.3% per patient-year. A marked increase was found in the mean postoperative left ventricular ejection fraction of the patients: 41.91% +/- 11.83%. Survivors were interviewed in person: their functional status was class I or II in 58 patients and class III in 3 patients. We conclude that left ventricular endoaneurysmorrhaphy results in satisfactory functional improvement and can be performed with relatively low early and late mortality rates.
Changes in thyroid hormone levels during and after cardiopulmonary bypass (CPB) are well documented. However, little is known about the effects of pulsatile flow during CPB on thyroid hormone metabolism. To examine the effect of flow pattern, a prospective study was carried out using 30 patients undergoing coronary artery bypass grafting. Fifteen patients had pulsatile flow during CPB and 15, nonpulsatile flow. Serum samples were obtained preoperatively, during bypass, and at 2 and 24 hours postoperatively. Thyroid-stimulating hormone, thyroxine (T4), triiodothyronine (T3), free T4, and free T3 levels were measured by radioimmunoassay. All measured hormone levels except free T4 and thyroid-stimulating hormone decreased after the initiation of CPB. There were no differences in preoperative values between the two groups. However, levels of T3 and free T3 during and after CPB showed a significant difference between the two groups, with a smaller decrease in patients in whom pulsatile flow was used during bypass (p < 0.05). Thyroxine, and thyroid-stimulating hormone free T4 values showed no difference between the two groups at any sampling time. These data provide support for the use of pulsatile flow during CPB to establish a more physiologic state and maintain better thyroid hormone metabolism.
OBJECTIVE: Aneurysms and dissections of the thoracic aorta continue to present a surgical challenge and their incidence is increasing in recent years. The mortality rate of surgical treatment is still higher than those of other cardiovascular operations. Neurological injury is the most feared complication resulting from repair of these lesions. This study aims to determine the factors that influence the neurological outcome and mortality after thoracic aortic operations. METHODS: During the period from November 1993 through May 1999, 144 patients were operated on for conditions involving the ascending aorta and/or aortic arch. Ninety-five (66.0%) were operated for aortic dissection and 49 (34.0%) were for aortic aneurysms. Sixty-two patients (43.1%) had replacement of ascending aorta with distal open technique; 82 patients (56.9%) had hemiarch or total arch replacement or repair of the distal arch. RESULTS: Twenty-seven (18.7%) early deaths occurred. New stroke occurred in two patients (1.4%) and temporary neurological dysfunction in nine patients (6.3%). Deep hypothermic circulatory arrest with retrograde cerebral perfusion was used in all patients. On multivariate logistic regression analysis, risk factors for mortality were chronic renal failure, preoperative organ malperfusion, rupture, total circulatory arrest time > 60 minutes, postoperative acute renal failure, postoperative low cardiac output, sepsis, and multiple organ failure. Risk factors for neurological morbidity were preoperative chronic renal failure, preoperative hemodynamic instability, postoperative low cardiac output, and pulmonary complications. CONCLUSIONS: Hypothermic circulatory arrest with retrograde cerebral perfusion was not an independent predictor of neurological morbidity on multivariate analysis, even if the arrest period was more than 60 minutes. Lengths of circulatory arrest periods and clinical presentations of the patients are important determinants of mortality.