Remote monitoring of left ventricular assist device parameters after HeartAssist-5 implantation.

Although several left ventricular assist devices (LVADs) have been used widely, remote monitoring of LVAD parameters has been available only recently. We present our remote monitoring experience with an axial-flow LVAD (HeartAssist-5, MicroMed Cardiovascular, Inc., Houston, TX, USA). Five consecutive patients who were implanted a HeartAssist-5 LVAD because of end-stage heart failure due to ischemic (n=4) or idiopathic (n=1) cardiomyopathy, and discharged from hospital between December 2011 and January 2013 were analyzed. The data (pump speed, pump flow, power consumption) obtained from clinical visits and remote monitoring were studied. During a median follow-up of 253 (range: 80-394) days, fine tuning of LVADs was performed at clinical visits. All patients are doing well and are in New York Heart Association Class-I/II. A total of 39 alarms were received from three patients. One patient was hospitalized for suspected thrombosis and was subjected to physical examinations as well as laboratory and echocardiographic evaluations; however, no evidence of thrombus washout or pump thrombus was found. The patient was treated conservatively. Remaining alarms were due to insufficient water intake and were resolved by increased water consumption at night and summer times, and fine tuning of pump speed. No alarms were received from the remaining two patients. We believe that remote monitoring is a useful technology for early detection and treatment of serious problems occurring out of hospital thereby improving patient care. Future developments may ease troubleshooting, provide more data from the patient and the pump, and eventually increase physician and patient satisfaction. Despite all potential clinical benefits, remote monitoring should be taken as a supplement to rather than a substitute for routine clinical visits for patient follow-up.

Robotics in cardiac surgery: the Istanbul experience.

BACKGROUND: Robots are sensor-based tools capable of performing precise, accurate and versatile actions. Initially designed to spare humans from risky tasks, robots have progressed into revolutionary tools for surgeons. Tele-operated robots, such as the da Vinci (Intuitive Surgical, Mountain View, CA), have allowed cardiac procedures to start benefiting from robotics as an enhancement to traditional minimally invasive surgery. METHODS: The aim of this text was to discuss our experience with the da Vinci system during a 12 month period in which 61 cardiac patients were operated on. There were 59 coronary bypass patients (CABG) and two atrial septal defect (ASD) closures. RESULTS: Two patients (3.3%) had to be converted to median sternotomy because of pleural adhesions. There were no procedure- or device-related complications. CONCLUSION: Our experience suggests that robotics can be integrated into routine cardiac surgical practice. Systematic training, team dedication and proper patient selection are important factors that determine the success of a robotic surgery programme.

Which may be effective to reduce blood loss after cardiac operations in cyanotic children: tranexamic acid, aprotinin or a combination?

BACKGROUND: Children with cyanotic heart disease undergoing cardiac surgery in which cardiopulmonary bypass is used are at increased risk of postoperative bleeding. In this study, the authors investigated the possibility of reducing postoperative blood loss by using aprotinin and tranexamic acid alone or a combination of these two agents. METHODS: In a prospective, randomized, blind study, 100 children undergoing cardiac surgery were investigated. In group 1 (n = 25) patients acted as the control and did not receive either study drugs. In group 2 (n = 25) patients received aprotinin (30.000 KIU.kg(-1) after induction of anesthesia, 30.000 KIU.kg(-1) in the pump prime and 30.000 KIU.kg(-1) after weaning from bypass). In group 3 (n = 25) patients received tranexamic acid (100 mg.kg(-1) after induction of anesthesia, 100 mg.kg(-1) in the pump prime and 100 mg.kg(-1) after weaning from bypass). In group 4 (n = 25) patients received a combination of the two agents in the same manner. Total blood loss and transfusion requirements during the period from protamine administration until 24 h after admission to the intensive care unit were recorded. In addition, hemoglobin, platelet counts and coagulation studies were recorded. RESULTS: Postoperative blood loss was significantly higher in the control group (group 1) compared with children in other groups who were treated with aprotinin, tranexamic acid or a combination of the two agents (groups 2, 3 and 4) during the first 24 h after admission to cardiac intensive care unit (40 +/- 18 ml.kg(-1).24 h(-1), aprotinin; 35 +/- 16 ml.kg(-1).24 h(-1), tranexamic acid; 34 +/- 19 ml.kg(-1).24 h(-1), combination; 35 +/- 15 ml.kg(-1).24 h(-1)). The total transfusion requirements were also significantly less in the all treatment groups. Time taken for sternal closure was longer in the control group (68 +/- 11 min) compared with treatment groups 2, 3 and 4, respectively (40 +/- 18, 42 +/- 11, 42 +/- 13 min, P < 0.05). The coagulation parameters were not found to be significantly different between the three groups. CONCLUSIONS: Our results suggested that both agents were effective to reduce postoperative blood loss and transfusion requirements in patients with cyanotic congenital heart disease. However, the combination of aprotinin and tranexamic acid did not seem more effective than either of the two drugs alone.

Combined radiofrequency modified maze and mitral valve procedure through a port access approach: early and mid-term results.

OBJECTIVE: The aim of this study was to assess the feasibility and effectiveness of irrigated radiofrequency (RF) modified Maze procedure through a port access approach during mitral valve surgery and evaluate early and mid-term results. MATERIAL AND METHOD: During a 16 months time period, 67 patients with chronic atrial fibrillation (AF) eligible for port access mitral valve surgery were randomly assigned to either Group A, in which they underwent a combined procedure (N = 33) or Group B, in which a valve procedure alone was performed (N = 34). Both groups were similar in terms of age, sex, valve pathology, duration of AF left atrial diameter and left ventricle function (P > 0.05). Four had undergone previous operations. RESULTS: Median follow-up was 10 months for both groups, 95% CI (9.18-10.8). One patient in each group died early postoperatively (3 and 2.9%). Two patients required reoperation for bleeding, one in each group (3 and 2.9%). There were two conversions to right thoracotomy. In Group A, freedom from AF was 100% at the end of the operation (76% sinus, 24% pacemaker) Six and twelve months freedom from AF was 87.2 and 93.6%, respectively. In Group B, freedom from AF at the end of operation was 41%. At the end of 6 and 12 months, freedom from AF was 9.4% (P = 0.0001). One patient in Group A required a permanent pacemaker (3%). During follow-up, one patient in Group A died of non-cardiac causes (3%). In Group B, there were two late deaths: one cardiac (2.9%) and one neurologic (2.9%). There were no thromboembolic events detected in Group A during follow-up, whereas two patients in Group B suffered this complication (6%, P = 0.081). At 12 months, functional capacity had improved for patients in both groups (P < 0.0001). CONCLUSION: The combination of mitral valve surgery and irrigated RF Maze procedure was safe and efficient through a port access approach. There were no procedure related complications like esophageal or coronary artery injury. Early and mid-term results were favourable with 93.6% of patients free of AF at 1 year in comparison to the 9.4% of the control group. The data is not sufficient to reach any conclusions in terms of thromboembolic rates, despite favourable results for the RF Maze group. Nevertheless, in terms of feasibilty, sinus rhythm restoration and overall outcome, early results are encouraging and we advocate the use of the combined procedure through a port access approach.

Intraoperative saline-irrigated radiofrequency modified Maze procedure for atrial fibrillation.

BACKGROUND: This study was conducted to evaluate the effectiveness of the saline-irrigated radiofrequency modified Maze operation for treatment of chronic atrial fibrillation, and to compare the results of the left and biatrial procedures. METHODS: During a period of 11 months, 62 patients with chronic atrial fibrillation who were having concomitant cardiac surgery underwent the procedure. The mean age of the patients was 52 +/- 14 years. Patients underwent either a biatrial (group A; n = 39) or left atrial (group B; n = 23) procedure. RESULTS: Two patients (3.2%) died early in the postoperative period. Three patients (4.8%) required reoperation for bleeding. One patient in group A (1.6%) received a permanent pacemaker. Patients in both groups were free of atrial fibrillation at the end of the procedure (group A: sinus 86.9%, pacemaker 13%; group B: sinus 90.5%, pacemaker 9.5%) (p > 0.05). At 1-month and longer-term follow-up, sinus rhythm was maintained in 92% and 95% of cases in group A, respectively, whereas this rate was 71% and 81% in group B (p > 0.05). Holter monitor surveillance revealed a higher rate of atrial fibrillation, atrial arrhythmias, and atrial flutter in group B (p < 0.05). Transthoracic echocardiography revealed improvement over time in left atrial transport function in both groups (p < 0.05). CONCLUSIONS: The saline-irrigated radiofrequency modified Maze procedure was performed safely and efficiently. Both the left and biatrial procedures were successful in terms of restoring sinus rhythm during short-term follow-up. Long-term follow-up with more cases is needed to show the superiority of one method over the other.

Effects of intravenous triiodothyronine during coronary artery bypass surgery.

A prospective randomized and double-blind study was performed to evaluate whether perioperative triiodothyronine administration has any effect on cardiovascular performance after coronary artery bypass surgery. Sixty patients were assigned to 2 groups of 30 each. When crossclamping ended, group A received an intravenous bolus of triiodothyronine, followed by infusion for 6 hours. Group B received a placebo. Serum triiodothyronine levels and hemo-dynamic parameters were serially measured. Mean postoperative cardiac index was slightly, but not significantly, higher in group A, whereas systemic vascular resistance was significantly lower in group A. Compared with preoperative values, serum triiodothyronine levels dropped significantly in group B at the end of cardiopulmonary bypass and remained low 12 hours postoperatively, while levels rose significantly in group A. No significant differences were detected between the groups in the incidence of arrhythmia, the need for inotropic support, intensive care unit stay, mortality, and morbidity. Perioperative administration of triiodothyronine increased cardiac output slightly and decreased systemic vascular resistance, but it had no effect on operative outcome. Routine use after coronary surgery is thus not recommended.

Does normoxemic cardiopulmonary bypass prevent myocardial reoxygenation injury in cyanotic children?

OBJECTIVE: To evaluate whether the deleterious effect of cardiopulmonary bypass (CPB) can be prevented by controlling PaO(2) in cyanotic children. DESIGN: Prospective, randomized, clinical study. SETTING: Single university hospital. PARTICIPANTS: Pediatric patients undergoing cardiac surgery for repair of congenital heart disease (n = 24). INTERVENTIONS: Patients were randomly allocated into 3 groups. Patients in the acyanotic group (group I, n = 10) had CPB initiated at a fraction of inspired oxygen (F(I)O(2)) of 1.0 (PO(2), 300 to 350 mmHg). Cyanotic patients were subdivided as follows: Group II (n = 7) had CPB initiated at an F(I)O(2) of 1.0, and group III (n = 7) had CPB initiated at an F(I)O(2) of 0.21 (PO(2), 90 to 110 mmHg). A biopsy specimen of right atrial tissue was removed during venous cannulation, and another sample was removed after CPB before aortic cross-clamping. The tissue was incubated in 4 mmol/L of t-butylhydroperoxide, and the malondialdehyde (MDA) level was measured to determine the antioxidant reserve capacity. Blood samples for cytokine levels, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 response to CPB were collected after induction of anesthesia and at the end of CPB before protamine administration. MEASUREMENTS AND MAIN RESULTS: After initiation of CPB, MDA level rose markedly in the cyanotic groups compared with the acyanotic group (210 +/- 118% v 52 +/- 34%, p < 0.05), which indicated the depletion of antioxidants. After initiation of CPB, TNF-alpha and IL-6 levels of the cyanotic groups were higher than for the acyanotic group (168 +/- 77 v 85 +/- 57, p < 0.001; 249 +/- 131 v 52 +/- 40; p < 0.001). When a comparison between the cyanotic groups was performed, group II (initiating CPB at an F(I)O(2) of 1.0) had significantly increased MDA production compared with group III (initiating CPB at an F(I)O(2) of 0.21) (302 +/- 134% v 133 +/- 74%, p < 0.05). Group II had higher TNF-alpha and IL-6 levels than group III (204 +/- 81 v 131 +/- 52, p < 0.001; 308 +/- 147 v 191 +/- 81, p < 0.01). CONCLUSION: Conventional clinical methods of initiating CPB at a hyperoxemic PO(2) may increase the possibility of myocardial reoxygenation injury in cyanotic children. This deleterious effect of reoxygenation can be modified by initiating CPB at a lower level of oxygen concentration. Subsequent long-term studies are needed to determine the best method of decreasing the oxygen concentration of the CPB circuit.

Clinical experience with coronary sinus catheterization in minimally invasive aortic valve surgery under transesophageal echocardiography guidance.

We aimed to show conventional coronary sinus (CS) catheter could be used with transesophageal echocardiography (TEE) guidance through the limited surgical field in aortic valve surgery with 'J' sternotomy. This method was performed in 14 patients and completed successfully in 12. We believe that in minimally invasive aortic valve surgery, the insertion of the conventional retrograde cardioplegia catheter to the CS with routine way may not be possible but application of TEE guidance is cost-effective and easily applicable method without significant complications.