Refik Tasoz

Comparative study of microfibrillar collagen hemostat (Colgel) and oxidized cellulose (Surgicel) in high transfusion-risk cardiac surgery

OBJECTIVE The effects of microfibrillar collagen hemostat (Colgel) and oxidized cellulose (Surgicel) on bleeding and allogeneic transfusions were compared in cardiac operations with a predicted high risk of bleeding. METHODS Between August 1999 and November 2001, 71 patients undergoing elective, high risk of bleeding operations were studied after giving informed consent. The procedures included repeat cardiac operations (aorta-coronary bypass operations or valvular operations), ascending aortic aneurysm repair necessitating deep hypothermic circulatory arrest, and ascending aortic grafting without deep hypothermic circulatory arrest. Subjects were excluded if they had recent (<5 days) acetylsalicylic acid ingestion, thrombolytic therapy, or anticoagulant therapy (heparin <4 hours preoperatively or warfarin <3 days preoperatively). Consenting subjects were randomized to receive either Colgel or Surgicel. RESULTS Chest tube drainage in the first 24 hours was 373 +/- 143 mL in the Colgel group and 571 +/- 144 mL in the Surgicel group (P =.01). Total postoperative chest tube drainage was 423 +/- 154 mL (range, 280-1100 mL) in the Colgel group and 677 +/- 128 mL (range, 285-1350 mL) in the Surgicel group (P =.01). In addition, chest tube drainage was compared between the 2 groups every 3 hours after operation. Blood loss in the first 3 postoperative hours was significantly less in the Colgel group (132 +/- 41 vs 228 +/- 57 mL, P <.001). In the following 3-hour interval, this significant difference persisted (67 +/- 24 vs 121 +/- 49 mL, P <.001). CONCLUSIONS In conclusion, the easy application, low cost, and significant blood-loss reduction effect of microfibrillar collagen powder renders this agent attractive for cardiac operations associated with high risk of bleeding.

Does sodium nitroprusside decrease the incidence of atrial fibrillation after myocardial revascularization?: a pilot study.

Background— Atrial fibrillation (AF) often occurs after coronary artery bypass grafting and can result in increased morbidity and mortality. In the present pilot study, our aim was to investigate whether sodium nitroprusside (SNP), as a nitric oxide donor, can reduce the frequency of post–coronary artery bypass grafting AF. Methods and Results— To investigate the effectiveness of SNP in the prophylaxis of AF, we conducted a prospective, randomized, placebo-controlled clinical study on 100 consecutive patients in whom we performed elective and initial CABG operations. A control group of 50 patients were treated with placebo (dextrose 5% in water), whereas the SNP group (n=50 patients) was treated with SNP (0.5 μg · kg−1 · min−1) during the rewarming period. High-sensitivity C-reactive protein levels were measured before surgery and 5 days postoperatively. All patients were monitored postoperatively with telemetry. Baseline characteristics were similar in both treatment groups. AF occurred in 12% of the SNP group and 27% of the control group. The occurrence of AF was significantly lower in the SNP group (P=0.005). The duration of AF in the SNP group was significantly shorter than that in the control group (5.33±1.86 and 7.55±1.94 hours, respectively; P=0.023). C-reactive protein levels were higher postoperatively in the control group than in the SNP group (P<0.05). Postoperative AF significantly prolonged postoperative hospital stay (P<0.05). Conclusions— The incidence of postoperative AF in the SNP group was reduced significantly. Further studies are needed to better delineate the anti-AF profile of SNP.

The effect of preoperative digitalis and atenolol combination on postoperative atrial fibrillation incidence

PURPOSE The most frequent arrhythmia after coronary artery bypass surgery is atrial fibrillation (AF). The prevention and treatment of this type of arrhythmia is subobtimal. Digitalis, beta-blockers, diltiazem and amiodarone are the preferred drugs for the treatment. This study was designed to compare the effects of preoperatively started digitalis and atenolol in combination and separately, on the incidence of AF that occurs within 7 days following the operation. MATERIALS AND METHOD One-hundred and sixty patients who had similar demographic properties were randomly grouped as group I, that preoperatively received combined drug therapy (n=40), group II preoperatively used digitalis (n=40), group III atenolol (n=40), and group IV was the control group (n=40). RESULTS Postoperative AF incidence was 25, 15,4, and 17,9% in groups IV, III, and II, respectively, whereas it was 5% in group I which was lower than all other groups, but the difference was only significant between groups I and IV (P=0.012). CONCLUSION The combined use of atenolol and digitalis preoperatively was considered as an efficient treatment for lowering the incidence of AF following coronary artery bypass surgery.

Native valve Brucella endocarditis.

Brucellosis is frequently seen in Mediterranean and Middle East countries, including Turkey. We report the medical and surgical management of 31 cases of native endocarditis.

Antiarrhythmic effect of magnesium sulfate after open heart surgery: effect of blood levels

BACKGROUND Arrhythmias following cardiac surgery is still a difficult complication to treat. Magnesium sulfate is an effective antiarrhythmic agent with negligible side effects. In this study, effects of magnesium sulfate as a first line antiarrhythmic agent was compared with results of two different well-accepted antiarrhythmic agents. METHODS One hundred patients with arrhythmia were prospectively randomized to a study and a control group. Lidocaine and amiodarone were accepted as standard antiarrhythmic agents. Patients in study group were received magnesium sulfate routinely as a first line antiarrhythmic agent. Unresponsive arrhythmias were treated with standard antiarrhythmic agents. Control group patients received only standard antiarrhythmics. RESULTS Magnesium sulfate alone was effective in 56% of the study group whereas 74% of the control group were responsive to standard antiarrhythmics (P=n.s.). In study group, a subgroup analysis according to blood levels of Mg2+ revealed that magnesium sulfate was more effective in patients with low Mg2+ levels (63% for low Mg2+ levels, 55% for normal Mg2+ levels, 36% for high Mg2+ levels) and ventricular arrhythmias (60% for ventricular and 40% for supraventricular arrhythmias), without statistical significance. CONCLUSIONS Magnesium sulfate is an effective and safe antiarrhythmic agent for arrhythmias developed after open-heart surgery. Its antiarrhythmic effect may relate to its pharmacological properties and unrelated to normalization of the circulating magnesium concentrations. We recommend its use as a first line antiarrhythmic agent without routine measurement of blood levels.

Primary benign schwannoma of the heart

We report herein a case of a 61-year-old woman who was found to have a mass adjacent to the left atrium. The tumor was resected giving least damage to the left atrium on cardiopulmonary bypass with a subsequent histological diagnosis of a schwannoma. Neurogenic tumors comprise 10% to 34% of mediastinal tumors. Nerve sheath tumors are more common in adults than in children, and these are equally malignant in children and adults. Nerve sheath tumors of the heart are extremely rare. Although there are many malignant cardiac neurilemomas reported, only a few cases of benign schwannomas have been reported. We describe a rare primary benign schwannoma of the left atrium.

Conduction disturbances in coronary artery bypass surgery.

BACKGROUND Conduction disturbances are very common after coronary artery bypass grafting (18-45%). Long cross-clamp time, method of cardioplegia, depth of hypothermia, and patient age are some of the risk factors. We planned this study to ascertain the effect of crystalloid or tepid blood cardioplegia (CP) on conduction disturbances. METHODS One hundred patients were randomly divided into two groups. The first group received tepid blood CP and the second received cold crystalloid CP. St. Thomas II CP was used as CCP and the same CP was mixed with blood with a ratio of 4:1 in the tepid CP group. In both groups as an initial bolus, a 10 to 15 ml/kg CP was infused with a pressure of 75 mmHg. Additionally, 400 ml of CP were given every 20 min during the cross clamping period in addition to infusion of 50-100 ml of CP after each distal anastomosis. Blood samples for CK, CK-MB, LDH and Troponin T measurements were obtained at induction, before bypass, after cross clamping, before de-clamping, after de-clamping and after bypass. Postoperative ECGs were analyzed by a cardiologist. RESULTS There were no deaths in both groups but the mean hospitalization was 8.4 +/- 1.7 days in group I, and 14.4 +/- 3.1 days in group II (P=0.004). Although there were significant rises in CK, CK-MB, LDH and Troponin T levels in both groups after CPB or de-clamping, the difference in increment between the two groups was not significant. Twelve patients in group II (24%) developed new fascicular blocks, four of these caused hemodynamic instability and needed inotropic treatment but only one was discharged with LAHB. Four patients in group I (8%) also developed new conduction disturbances within the first hour, but all completely resolved. Incidence of conduction disturbances was significantly increased in the crystalloid CP group (P=0.019). CONCLUSION There were no significant differences in cardiac enzyme measurements between cold crystalloid and tepid blood CP, but crystalloid CP caused more fascicular blocks. We conclude that myocardial protection was equal in both cardioplegia methods whereas conduction disturbances have been assumed to be caused by cold injury to the conduction tissues.

Effects of carbamazepine on spinal cord ischemia

BACKGROUND Prophylactic treatment with carbamazepine has been shown to reduce the cerebral damage and neurologic deficit in ischemic conditions. A randomized controlled study based on a rabbit model was designed to study the effect of carbamazepine on a spinal cord ischemic reperfusion injury. METHODS Thirty New Zealand rabbits were randomly assigned to 1 of the 2 groups (n = 15 per group): group I (control group) and group II (carbamazepine group). Spinal cord ischemia was induced by infrarenal aortic crossclamp for 25 minutes in both groups. Functional evaluation with the Tarlov score during a 2-day observation period and histopathologic assessment of the lumbar spinal cord were performed. Changes in spinal cord morphology were observed with hematoxylin-eosin staining and electron microscopy. Gray matter damage was assessed on the basis of the number of normal neurons in the ventral horn. RESULTS Diffuse destruction of gray matter with moderate to severe vacuolization and essentially no normal ganglion cells was observed in the spinal cord of rabbits in the control group, whereas specimens of rabbits assigned to the carbamazepine group showed ganglion cells with normal nuclei and cytoplasm (P < .0001). Neurologic impairment was significantly attenuated in the carbamazepine group compared with the Tarlov scores of the control group (P < .0001 at day 2). CONCLUSION Carbamazepine may protect the spinal cord from ischemic reperfusion injury that is associated with ameliorated neurologic and histopathologic results.

Giant Posterolateral Left Ventricular Aneurysm Diagnosed 6 Weeks After Incomplete Surgical Revascularization

We report the surgical repair of a true left ventricular aneurysm diagnosed 6 weeks after incomplete surgical revascularization.

Off-pump coronary artery surgery in a patient with essential thrombocythaemia: two life-threatening complications in the same patient.

Essential thrombocythaemia (ET) is a rare chronic myeloproliferative disease characterised by persistent thrombocytosis. Cerebral, myocardial and peripheral thrombosis are frequently seen complications, but bleeding and venous thrombosis are more rare. Here, a case of essential thrombocythaemia complicated by cerebral and myocardial thrombosis is presented. The patient’s platelet count was 680×109/litre on admission. Electrocardiogram showed a slight ST elevation in leads V1 to V4. A coronary angiography was performed and it revealed a severe stenosis of the left anterior descending artery. The patient had a successful off-pump coronary artery bypass grafting surgery. After the operation the platelet count was 390×109/litre. The patient received hydroxyurea and aspirin treatment preoperatively and continued postoperatively. ET is a rare myeloproliferative disease; its complications are also rare, but the occurrence of two life-threatening complications in the same patient is rarer still. Further investigations are needed to determine the risk stratification for patients with ET undergoing cardiac surgery.