Diagnostic accuracy of Doppler ultrasonography for assessment of internal thoracic artery graft patency.

OBJECTIVE: The main purpose of this study was to assess the patency of left internal thoracic artery (LITA) graft by using color Doppler ultrasonography (CDUSG) and furthermore to determine the sensitivity and specificity of CDUSG for patency by using coronary angiography as the reference standard. METHODS: This study is an observational cohort study on diagnostic accuracy that was held between August 2008 and October 2009. CDUSG was performed in 138 consecutive patients who had angina symptom or positive ischemic findings following coronary artery bypass surgery. LITA blood flow velocity at peak-systole (PSV), diastole (PDV) and end-diastole (EDV) was recorded. All patients were also assessed by coronary angiography for LITA graft patency. Statistical analysis was performed by using independent samples t-test, Mann-Whitney U test, chi-square test and receiver operating curve analyses (ROC). RESULTS: Seventy-eight of all patients had functional LITA grafts and 59 patients had dysfunctional LITA grafts according to CDUSG-derived parameters, whereas we cannot conclude about one patient's LITA graft functionality. The LITA grafts were visualized angiographically in all cases. Of all 138 patients, 60 patients had dysfunctional LITA grafts after angiographic evaluation. The ROC analyses showed that PDV (AUC=0.899, 95% CI 0.844 to 0.953; p<0.001) and EDV (AUC=0.900; 95% CI 0.847 to 0.953; p<0.001) values were also strongly associated with graft functionality. We found out that CDUSG predicts LITA graft functionality with a sensitivity and specificity of 100% and 98.4% respectively. The accuracy of the CDUSG was calculated as 99.3%. CONCLUSION: CDUSG is a reliable non-invasive method for assessment of LITA graft patency.

The relationship between low intraoperative hematocrit levels during cardiopulmonary bypass and postoperative neurological events.

OBJECTIVE: The objective of our study is to analyze whether low intraoperative hematocrit levels have an effect upon postoperative neurological events. METHODS: Our study included 140 patients who underwent isolated coronary bypass under cardiopulmonary bypass between 2009 and 2012. The main group of the study was 70 patients with intraoperative hematocrit levels lower than 22%. These patients' 30-day postoperative neurological (particularly stroke) follow up was registered as the main data of the study. Another group of 70 patients possessing the same demographic features who underwent open heart surgery with hematocrit levels remaining above 22% were registered as the control group for perioperative neurological data. RESULTS: The average age of the patients with hematocrit levels below and above 22% was 56.8 ± 5.8 years and 54.1 ± 7.3 years, respectively. The mean follow-up period of the patients was 37.2 ± 8.6 days. None of the patients had any neurological postoperative sequalae. No mortalities occurred. One patient who had mild paresthesia and motor weakness of the left hand had no pathological finding on computed tomography and was diagnosed with peripheral neuropathy due to intraoperative sternal retraction. CONCLUSION: Because our study revealed no cerebrovascular events, coronary bypass surgery under cardiopulmonary bypass may be safely conducted even in patients with hematocrit levels lower than 22%.

Effectiveness of prophylactic levosimendan in high-risk valve surgery patients.

OBJECTIVE: Levosimendan has anti-ischaemic effects, improves myocardial contractility and increases systemic, pulmonary and coronary vasodilatation. These properties suggest potential advantages in high-risk cardiac valve surgery patients where cardioprotection would be valuable. The present study investigated the peri-operative haemodynamic effects of prophylactic levosimendan infusion in cardiac valve surgery patients with low ejection fraction and/or severe pulmonary arterial hypertension. METHODS: Between May 2006 and July 2007, 20 consecutive patients with severe pulmonary arterial hypertension (systolic pulmonary artery pressure ≥ 60 mmHg) and/or low ejection fraction (< 50%) who underwent valve surgery in our clinic were included in the study and randomised into two groups. Levosimendan was administered to 10 patients in group I and not to the 10 patients in the control group. Cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (MPAP) were recorded for each patient preoperatively and for 24 hours following the operation. RESULTS: CO and CI values were higher in the levosimendan group during the study period (p < 0.05). MPAP and PVR values were significantly lower in the levosimendan group for the 24-hour period (p < 0.05) and SVR values were significantly lower after 24 hours in both groups. When clinical results were considered, no difference in favour of levosimendan was detected regarding the mortality and morbidity rates between the groups. CONCLUSION: Levosimendan improved the haemodynamics in cardiac valve surgery patients with low ejection fraction and/or severe pulmonary arterial hypertension, and facilitated weaning from cardiopulmonary bypass in such high-risk patients when started as a prophylactic agent.

Does on-pump normothermic beating-heart valve surgery with low tidal volume ventilation protect the lungs?

BACKGROUND: Postoperative pulmonary dysfunction following cardiopulmonary bypass (CPB) usually develops secondary to the inflammatory process with contact activation, hypothermia, operative trauma, general anesthesia, atelectasis, pain, and pulmonary ischemia/reperfusion due to cross-clamping. The aim of the present study was to evaluate the effects of an on-pump, normothermic, and beating-heart technique and of low-volume ventilation on lung injury. METHODS: We compared the results for 20 patients who underwent operations with an on-pump, normothermic, and beating-heart technique of mitral valve surgery with low-volume ventilation (group 1) with the results for 23 patients who underwent their operations with an on-pump, hypothermic cardiac-arrest technique (group 2). In both groups, blood samples were collected from the right superior pulmonary vein, and inflammation and oxidative stress markers (malondialdehyde, lactic acid, platelet-activating factor, and myeloperoxidase) were studied. RESULTS: Malondialdehyde, myeloperoxidase, and lactate values were significantly lower in group 1 than in group 2 just before the termination of CPB (P < .05). We observed no differences between the 2 groups with regard to values for platelet-activating factor. CONCLUSIONS: Inflammation and oxidative stress markers were lower in the group of patients who underwent beating-heart valve surgery with low-volume ventilation. These results reflect less of an ischemic insult and lower inflammation compared with the results for the patients who underwent conventional operations.

Beating heart versus conventional mitral valve surgery.

OBJECTIVES: The present study aimed to compare the results of beating heart technique and conventional mitral valve surgery (MVS). METHODS: Three hundred and nineteen patients who underwent MVS between April 2005 and December 2006 were enrolled in the study. While 125 patients underwent beating heart MVS (group 1), the conventional approach was used for 194 patients (group 2). Of those patients who underwent beating heart MVS, 75 underwent MVS without cross-clamping the aorta. Coronary sinus retroperfusion was used during surgery in the remaining 50 patients. The right anterolateral thoracotomy was performed in nine out of the 29 patients requiring re-operation, while resternotomy was performed in 20. RESULTS: No significant differences were shown between the groups in the preoperative period in terms of the Parsonnet mortality score, Ontario mortality score, and length of intensive care stay. However, there were significant differences with respect to EuroSCORE risk score, EuroSCORE mortality, and Parsonnet risk score, and length of hospital stay according to Ontario risk scoring. It was established that the patients in group 1 had a shorter length of hospital stay [group 1: six days (range, 4-37 days); group 2: 10 days (range, 4-62 days)]. Group 1 was observed to have shorter time periods when the groups were compared regarding operative time [group 1: 130 min (range, 100-270 min); group 2: 240 min (range, 100-360 min)], cross-clamping (XCL) time [group 1: 27.5 min (range, 3-99 min); group 2: 60.5 min (range, 30-163 min)], and cardiopulmonary bypass time [group 1: 57 min (range, 22-150 min); group 2: 90 min (range, 39-388 min)]. There were also significant differences in favor of group 1 in terms of postoperative need for inotropic support [group 1: 26 patients (16%); group 2: 68 patients (35%)]. Although there were no statistically significant differences in the groups in terms of mortality rates according to the Parsonnet scoring system, with the exception of the moderate risk group, it was noted that the mortality rates in the beating heart group were lower. CONCLUSIONS: This study concluded that beating heart MVS can be performed successfully, particularly for patients at higher risk which will lead to increased morbidity and mortality in postoperative period.

Treatment of mechanical aortic valve thrombosis: fibrinolytic treatment versus surgical intervention: result of eight cases.

OBJECTIVE: : Thrombosis of mechanical heart valve prosthesis is a rare fatal complication after heart valve replacement. Although surgical intervention is the suggested treatment in many series, fibrinolytic treatment offers a good alternative. We describe eight cases with mechanical aortic valve thrombosis and compare their results after fibrinolytic treatment or redo aortic valve replacement. METHODS: : Between February 2008 and March 2009, eight patients with previous mechanical prosthetic aortic valve replacement history were admitted to our center with mechanical aortic valve thrombosis. Four patients were operated, and the remaining four patients received low-dose fibrinolytic treatment. All patients' data were collected prospectively. RESULTS: : Two of the four operated patients died. In the fibrinolytic group, all patients totally recovered, and there was no mortality or morbidity during the follow-up period. CONCLUSIONS: : We thought that fibrinolytic treatment is a feasible and effective method for thrombosed mechanical aortic valve. However, much more populated patient groups are needed for the vigorous inference.

Levosimendan and severe pulmonary hypertension during open heart surgery.

Weaning from cardiopulmonary bypass is the most important stage during mitral valve surgery, especially in patients with severe pulmonary hypertension. We report two patients with severe pulmonary hypertension who were operated on because of valvular heart disease. To reduce the pulmonary artery pressure, levosimendan was used because of its vasodilatory and cytoprotective effects. All patients tolerated the operation and levosimendan administration. Their postoperative course was uneventful. Levosimendan can be used to treat pulmonary hypertension during operations for heart valve disease. Patients clearly benefit from the vasodilator action of the drug for reducing pulmonary artery pressure.

Tricuspid valve replacement and levosimendan.

Isolated tricuspid valve replacement, which is not a common operation, is associated with poor short and long-term results, and the postoperative morbidity and mortality rates are high. The main reason for these adverse effects is the acute manifestation of chronic right heart failure. To treat right heart failure, we used levosimendan for its inotropic and vasodilatatory effects, and it does not increase the calcium overload in myocardial cells. We report two cases of tricuspid valve replacement operations performed using levosimendan. Both patients receiving levosimendan tolerated the operations well, and their postoperative courses were uneventful.

Residual postmyocardial infarction ventricular septal defect repair through right atrium with right thoracotomy on beating heart technique.

BACKGROUND AND AIM: The incidence of residual opening after repair of postmyocardial infarction ventricular septal defect (VSD) was reported to be 10% to 25%. Redo surgery with remedial sternotomy is more complex than primary surgery and is consequently associated with higher mortality and morbidity due to the myocardial and patent coronary grafts injury during pericardial dissection. METHODS: A 59-year-old female patient had coronary artery bypass grafting and closure of post myocardial infarction ventricular septal defect with patch 10 months earlier in a different cardiac center. She was admitted to the hospital for severe congestive heart failure. RESULTS: She was operated because of the residual opening after repair of post myocardial infarction ventricular septal defect. Post myocardial infarction ventricular septal defect closure was performed through the right atrium by on-pump beating heart technique via the right thoracotomy. CONCLUSIONS: Closure of post myocardial infarction ventricular septal defect with this technique offers an alternative and safe approach to repair of the residual VSD when the coronary bypass grafts are patent.

Mitral valve replacement with the beating heart technique in a patient with previous bypass graft from ascending to descending aorta due to aortic coarctation.

BACKGROUND AND AIM: Conventional mitral valve replacement (MVR) is carried out under cardioplegic arrest with cross-clamping of the ascending aorta during cardiopulmonary bypass. In this case, MVR was performed with on-pump beating heart technique without cross-clamping the aorta because of the diffuse adhesion around the ascending aorta, and tube graft presence between ascending and descending aortas. METHODS: A 47-year-old female patient had aorto-aortic bypass graft from ascending aorta to descending aorta with median sternotomy and left thoracotomy in single stage because of aortic coarctation 2 years ago in our cardiac center. She was admitted to the hospital with palpitation and dyspnea on mild exertion. Transthoracic echocardiography revealed 4th degree mitral insufficiency. RESULTS: MVR was carried out through remedian sternotomy with on-pump beating heart technique without cross-clamping the aorta. CONCLUSIONS: MVR with on-pump beating heart technique offers a safe approach when excessive dissection is required to place cross-clamp on the ascending aorta.