[Comparison of sternotomy off-pump coronary artery bypass and minimally invasive technique for isolated single vessel grafting].

OBJECTIVE: To compare the outcomes of minimally invasive coronary artery bypass grafting operation performed via a small thoracotomy versus da Vinci S system (Endo-A-CAB) with sternotomy off-pump coronary artery bypass grafting (OPCAB) for single vessel lesion. METHODS: From April 2000 to August 2011, a total of 194 patients with single coronary artery stenosis accepted CABG on beating heart were divided into 2 groups by different surgical approaches. Group A (n = 99) received sternotomy OPCAB while Group B (n = 95) underwent Endo-A-CAB. All patients had a history of unstable angina and coronary arteriography showed severe stenosis in left anterior descending artery (LAD). The procedure performed in Group B included robotic internal mammary artery (IMA) harvesting and single manual anastomosis to LAD and/or diagonal branch through small incision thoracotomy. IMA flow was evaluated by the Doppler flow meter after the completion of anastomosis. Grafting patency was evaluated postoperatively by computed tomography angiography (CTA) or angiography. RESULTS: The ventilation time and postoperative drainage volume in Group B were less than those in Group A ((5.1 ± 2.1) vs (10.1 ± 5.8) h, P = 0.03; (411 ± 295) vs (605 ± 244) ml, P = 0.000). No significant difference existed in blood flow, mortality and postoperative complication morbidity between two groups. All symptoms of angina disappeared. CONCLUSION: As a new advanced modality of revascularization, in comparison with OPCAB, Endo-A-CAB procedure is a less invasive and safer method of coronary artery bypass grafting for single vessel lesion.

[Surgical treatment with modified Morrow procedure in hypertrophic obstructive cardiomyopathy].

OBJECTIVE: To summarize the experience of ventricular septal myectomy (modified Morrow procedure) in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: From June 2003 to March 2011, 38 patients (26 male and 12 female) with HOCM underwent modified Morrow procedure. The mean age was 36.3 years (ranging from 18 to 64 years). The diagnosis was made by echocardiography and spiral CT. The mean systolic gradient between the left ventricle and the aorta from transthoracic echocardiography (TTE) was (89±31) mmHg (ranging from 50 to 184 mmHg, 1 mmHg=0.133 kPa) before operation. There was moderate or severe systolic anterior motion (SAM) in 38 cases and mitral regurgitation in 29 cases. Ventricular septal myectomy with modified Morrow procedure was performed in all 38 cases. TEE was used intraoperatively to evaluate the results of the surgical procedures. After 1 to 2 weeks of operation, TTE was performed to evaluate the effect of operation. All patients were followed up with TTE after operation. RESULTS: All patients were discharged without complications. Intraoperative TEE showed that the mean systolic gradient between the left ventricle and the aorta was decreased from (95±36) mmHg before procedures to (14±11) mmHg after operation (t=13.265, P=0.000), and the thickness of ventricular septum was decreased from (28±8) mm to (12±3) mm (t=11.656, P=0.000). TTE showed that the mean systolic gradient between the left ventricle and the aorta was decreased from (89±31) mmHg preoperatively to (18±13) mmHg (t=12.729, P=0.000) in 1 to 2 weeks after operation. Mitral regurgitation and SAM were significantly improved or disappeared (t=7.930, t=5.213, both P=0.000). During the follow-up, all patients promptly became completely asymptomatic or complained of mild effort dyspnea only and syncope was abolished, and TTE showed that the pressure gradient was kept on the postoperative level or slightly decreased (P=0.494). CONCLUSIONS: Ventricular septal myectomy with modified Morrow procedure is a mostly effective method for patients with HOCM. Good surgical exposure and the hypertrophied septum thoroughly excised are paramount for successful surgery.

[Early and midterm outcomes of coronary artery bypass grafting in octogenarians].

OBJECTIVE: To investigate the early and midterm postoperative outcomes and analyze risk factors of coronary artery bypass grafting (CABG) in octogenarians. METHODS: Clinical data of 38 patients aged 80 years or greater receiving isolated coronary artery bypass grafting from September 2001 to November 2010 were reviewed. There were 33 male and 5 female patients, aging from 80 to 87 years with a mean of (82.6 ± 1.2) years. Twelve patients underwent conventional (on-pump) CABG and 26 patients underwent off-pump CABG. The number of bypass grafts was 1 to 5 (mean 2.5 ± 1.1). Left internal mammary artery was used in 37 (97.3%) patients. RESULTS: The perioperative mortality was 2.6% (1/38). Postoperative complications included stroke (4 cases), respiratory infection (1 case). The atrial arrhythmias occurred in 25 patients. Intensive care unit and hospital length of stay lasted (3.8 ± 1.4) days and (15 ± 6) days, respectively. Totally 38 patients were followed up for 4 to 70 months. Six patients died during the follow-up period. The 92.6% patients recovered without any cardiac events. CONCLUSIONS: Isolated CABG can be performed safely with acceptable postoperative morbidity and mortality in octogenarians. Appropriate surgical strategy and intensive perioperative treatment must be enhanced in octogenarians who underwent CABG.

[Diagnostic study on the coronary artery bypass grafts lesions using 64 multi-slice computed tomography angiography].

OBJECTIVE: To evaluate the diagnostic accuracy in the assessment of coronary artery bypass grafts using 64 multi-slice computed tomography angiography (64-MSCTA) technology. METHODS: There were 228 patients post coronary artery bypass grafting (CABG) underwent 64-MSCTA from July 2005 to April 2007. Thirty-one patients with 82 bypass grafts performed coronary angiography (CAG) because of angina or grafts lesion showed by 64-MSCTA. RESULTS: All bypass grafts could be visualized by 64-MSCTA. Thirteen bypass graft occlusions and fourteen significant stenosis were detected by 64-MSCTA and confirmed by CAG. One venous grafts distal anastomosis was missed and another one was miss diagnosed as stenosis. One false negative and one false positive CT-finding resulted in a sensitivity of 93.3%, a specificity of 98.1%, a positive predictive value of 93.3%, a negative predictive value of 98.1% and an accuracy of 97.1% for grafts stenosis. As to the grafts lesion, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for grafts occlusion were 96.4%, 98.1%, 96.4%, 98.1% and 97.6%, respectively. CONCLUSION: 64-MSCTA demonstrates high diagnostic accuracy in the assessment of graft patency and suitable for the follow-up of patients post CABG.

[A comparative study on grafts' blood flow after on-pump and off-pump coronary artery bypass surgeries].

OBJECTIVE: To compare the grafts' blood flow after on-pump and off-pump coronary artery bypass graftings. METHODS: Five hundred and forty-seven cases were studied, including four hundred and three cases undergoing off-pump coronary artery bypass (OPCAB, off-pump group) and one hundred and forty-four cases undergoing on-pump coronary artery bypass (CCABG, on-pump group). In all cases left internal mammary artery (LIMA) was routinely anastomosed to left anterior descending artery (LAD), and saphenous vein (SV) to the other target vessels in sequential mode when there were more than two anastomoses. After all anastomoses were completed and hemodynamic status was stable, transit time flow-meter was utilized to measure and record the grafts' flow wave, pulsatility index (PI), value of mean flow, diastolic and systolic peak flow, vascular resistance, insufficiency ratio and mean blood pressure. RESULTS: PI, insufficiency ratio and diastolic peak flow of LIMA in off-pump group were 2.7 +/- 1.8, (2.2 +/- 4.3)%, (46.8 +/- 2.7) ml/min respectively; those in on-pump group were 2.8 +/- 2.0, (3.4 +/- 3.1)% and (52.8 +/- 3.7) ml/min respectively. And those of SV in off-pump group were 2.8 +/- 0.1, (1.8 +/- 0.3)% and (85.8 +/- 3.2) ml/min respectively and those in on-pump group were 2.6 +/- 0.2, (1.3 +/- 0.2)% and (93.9 +/- 5.6) ml/min respectively. For both LIMA and SV grafts' blood flow there was no significant difference in PI, insufficiency ratio, diastolic peak flow and mean blood pressure in both groups (P > 0.05). The mean flow and systolic peak flow in off-pump group were significantly less than those in on-pump, while the vascular resistance in off-pump group was significantly greater than that in on-pump group (P < 0.01). CONCLUSION: There is no significant difference in grafts' patency between OPCAB and CCABG.

[Clinical analysis of 1018 cases of coronary artery bypass grafting].

OBJECTIVE: To analyze retrospectively 1018 patients who underwent coronary artery bypass grafting surgery (CABG) in order to summarize surgical techniques and clinical outcome. METHODS: From 1997 through 2004, data of same surgeon for 508 patients who underwent conventional coronary artery bypass surgery on pump (CCABG) and 510 patients who underwent off-pump CABG (OPCAB) were collected and analyzed retrospectively. Eight hundred and fifty-two patients had unstable angina, 582 patients were over 60 years old (57.2%) and 784 patients had concomitant diseases including valve lesion, hypertension, diabetes, myocardial infarction, left ventricular aneurysm with septal defect, stroke, chronic obstructive pulmonary diseases, renal failure and cancer. A hundred and fifty-six patients had left main stem (LIMS) stenosis and 671 patients, triple-vessel disease. RESULTS: Total mortality was 0.39% (4-case death) and morbidity, 1.6% (sternal dehiscence, stroke and mediastinitis). The grafts per patient with CCABG and OPCAB were 3.3 +/- 0.6 vs. 2.5 +/- 0.4. Left internal mammary artery use was 93.8% of the patients, 29 patients were implanted intra-aortic balloon pump intraoperatively. Follow-up was 4 months to 7 years. CONCLUSIONS: Scientific surgical strategies, excellent surgical techniques and improvement of cardiac anesthesia and cardiopulmonary bypass make the mortality and morbidity decrease significantly, CABG surgery is safe and effective in patients with coronary artery disease.

Relation between responsiveness to neurotransmitters and complexity of epileptiform activity in rat hippocampal CA1 neurons.

PURPOSE: Our previous works suggested that sensitivity of neurons with chaotic firing patterns to stimuli is significantly greater than that in neurons with periodic firing patterns, which shows that responsiveness of neurons may depend on the complexity of the firing series. This study was performed to determine the relation between responsiveness of the hippocampal CA1 neurons with epileptiform activity (EA) to neurotransmitters and their complexity of firing series. METHODS: Firing series of CA1 neurons were recorded extracellularly in rat hippocampal slice. Approximate entropy was used to describe the complexity of the interspike interval (ISI) series. EA was induced by local application of penicillin (1,000 IU/ml). The change of firing rate induced by neurotransmitters (glutamate and gamma-aminobutyric acid) was compared with that of the degree of complexity of ISI series in the process of EA. RESULTS: The excitatory responses to glutamate and the inhibitory responses to gamma-aminobutyric acid in CA1 neurons appeared to be decreased during the process of penicillin-induced EA. However, during this same process, the approximate entropy of the ISI series also was decreased significantly. CONCLUSIONS: The results suggest that the reduced responses to neurotransmitters of the CA1 neurons appear to be closely related to the onset of EA. Furthermore, these neurons show that the changes in responsiveness are closely parallel to the decrease of degree of complexity of firing series during penicillin epileptogenesis.