Propofol-Induced Vasodilation in Human Internal Mammary Artery: Role of Potassium Channels.

OBJECTIVES: The aim of this study was to investigate the vascular effects and mechanisms of propofol in the human internal mammary artery (IMA). DESIGN: In vitro experimental study. SETTING: The study was conducted in the research laboratory of a pharmacology department. PARTICIPANTS: IMA segments were obtained from 52 patients undergoing coronary artery bypass surgery. INTERVENTIONS: The IMA rings were suspended in isolated organ baths, and the changes in the tension were isometrically recorded. The antagonistic effect of propofol (1 µM, 10 µM, and 100 µM) on contractions induced by potassium chloride (45 mM), phenylephrine (1 µM), 5-hydroxytryptamine (30 µM), and calcium chloride (10 µM-10 mM) was investigated. The relaxations induced by propofol also were tested in the presence of the nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (100 mM); the cyclooxygenase inhibitor, indomethacin (10 mM); and the potassium ion channel inhibitors, tetraethylammonium (1 mM), iberiotoxin (20 nM), glibenclamide (10 µM), 4-aminopyridine (1 mM), and barium chloride (30 µM). MEASUREMENTS AND MAIN RESULTS: Propofol caused a significant concentration-dependent vasorelaxation, which was endothelium independent. It inhibited the contractions induced by potassium chloride, phenylephrine, 5-hydroxytryptamine, and calcium chloride (p < 0.001), but it did not affect the basal tension. Propofol-induced relaxation was significantly inhibited by iberiotoxin and tetraethylammonium (p < 0.001); however, it was not affected by 4-aminopyridine, glibenclamide, and barium chloride. CONCLUSION: This study clearly reveals that propofol relaxes the IMA, and propofol-induced vasodilation may be related to large conductance calcium ion-activated potassium ion channel activation. Propofol use in coronary artery bypass surgery can be valuable via its favorable vasodilator effect to overcome perioperative vasospasm of IMA.

Comparison of intestinal ischemia after on-pump versus off-pump coronary artery bypass grafting surgery

Background/aim: Acute mesenteric ischemia (AMI), one of the gastrointestinal system complications, which occurs following cardiac surgery, is challenged in the literature with a diminished incidence of AMI by heart surgery without cardiopulmonary bypass (CPB) or with pulsatile CPB. This study aims to compare the incidence and mortality rate of mesenteric ischemia in a series of consecutive patients undergoing coronary artery bypass grafting (CABG) through on-pump and off-pump techniques. Materials and methods: This study included patients who underwent CABG between 1 January 2010 and 31 June 2016. All patients were divided into two groups: Group 1 comprised 6396 CABG patients operated on with the off-pump technique. Group 2 included 1210 patients who received CABG with the on-pump technique. Preoperative data were collected on the studied variables. Postoperative data included the development of intestinal ischemia and in-hospital mortality. Results: Of 7606 consecutive CABG patients, a total of 31 (0.4%) developed intestinal ischemia. The incidence of postoperative mesenteric ischemia was 0.28% in Group 1 and 1.07% in Group 2 (P = 0.000). The survival rates after AMI were 61.1% in Group 1 (off-pump) and 7.7% in Group 2 (on-pump) (P = 0.003). Time from the first occurrence of nonspecific GI complaints to laparotomy was similar in the off-pump and on-pump groups and had no effect on mortality. Conclusions: With regard to the incidence of mesenteric ischemia and survival after laparotomy, off-pump CABG patients revealed significant improvement compared with those operated on with the on-pump technique.

Sequential left internal mammary artery grafting in combination with the aortic no-touch technique.

Aim: This study aimed to investigate the short-term outcomes achieved with off-pump bypass combined with the aortic no-touch technique where sequential anastomoses between the left internal mammary artery (LIMA), left anterior descending (LAD) and diagonal artery were employed. Material and methods: A total of 583 patients (mean age 63, 80% male) who underwent off-pump bypass (LIMA-diagonal-LAD sequential) were enrolled in this retrospective analysis. Data regarding the frequency of in-hospital postoperative complications, intra-aortic balloon pump (IABP) and inotropic agent requirement, re-exploration for bleeding, and length of hospital stay were collected. Anastomosis patency was evaluated in 49 patients who underwent angiography. Results: 2.6% of the participants received inotropic agents and 0.5% required IABP. Frequency of acute renal failure, sternal wound infection, cerebrovascular event, respiratory failure, and hemodialysis was less than 1% in total. Among the 49 patients undergoing angiography at an average 41 ±17 months after bypass, the LIMA-LAD was patent in 98% and the LIMA-diagonal was patent in 84% of the subjects. Preoperative left ventricle ejection fraction (LVEF) and recent myocardial infarction (MI) prior to bypass were significantly correlated with postoperative IABP and inotropic agent requirement (r = 0.165, p < 0.01 for LVEF, p = 0.021 for recent MI). Conclusions: Off-pump bypass in combination with the aortic no-touch technique is associated with favorable postoperative outcomes including reduced postoperative stroke, renal dysfunction, IABP, and inotropic agent requirement compared to the results of previous randomized prospective studies published in the literature.

Intramyocardial Transplantation of Umbilical Cord Mesenchymal Stromal Cells in Chronic Ischemic Cardiomyopathy: A Controlled, Randomized Clinical Trial (HUC-HEART Trial).

BACKGROUND AND OBJECTIVES: The HUC-HEART Trial (ClinicalTrials.gov Identifier: NCT02323477) was a controlled, prospective, phase I/II, multicenter, single-blind, three-arm randomized study of intramyocardial delivery of human umbilical cord-derived mesenchymal stromal cells (HUC-MSCs) combined with coronary artery bypass-grafting (CABG) in patients with chronic ischemic cardiomyopathy (CIC). The trial aimed to assess (i) the safety and the efficacy of cell transplantation during one-year follow-up, (ii) to compare the efficacy of HUC-MSCs with autologous bone-marrow- derived mononuclear cells (BM-MNCs) in the same clinical settings. METHODS AND RESULTS: Fifty-four patients who were randomized to receive HUC-MSCs (23×106) (n=26) or BM-MNCs (70×107) (n=12) in combination with CABG surgery. The control patients (n=16) received no cells/vehicles but CABG intervention. All patients were screened at baseline and 1, 3, 6, 12 months after transplantation. Forty-six (85%) patients completed 12 months follow-up. No short/mid-term adverse events were encountered. Decline in NT-proBNP (baseline∼ 6 months) in both cell-treated groups; an increase in left ventricular ejection fraction (LVEF) (5.4%) and stroke volume (19.7%) were noted (baseline∼6 or 12 months) only in the HUC-MSC group. Decreases were also detected in necrotic myocardium as 2.3% in the control, 4.5% in BM-MNC, and 7.7% in the HUC-MSC groups. The 6-min walking test revealed an increase in the control (14.4%) and HUC-MSC (23.1%) groups. CONCLUSIONS: Significant findings directly related to the intramyocardial delivery of HUC-MSCs justified their efficacy in CIC. Stricter patient selection criteria with precisely aligned cell dose and delivery intervals, rigorous follow-up by detailed diagnostic approaches would further help to clarify the responsiveness to the therapy.

Isolated Sternal Cleft in a Patient With Coronary Artery Disease.

A cleft sternum is a very rare developmental anomaly. It is caused by failure of fusion of the two lateral mesodermal sternal bars which later form the sternum. Diagnosis of cleft sternum is generally made in the neonatal period, and it is usually associated with other congenital defects. Occasionally, patients with cleft sternum may be reported late in the childhood or even in adulthood. We present the case of an adult patient with sternal cleft diagnosed incidentally in the perioperative period at the time of off-pump coronary artery bypass grafting. No other skeletal or cardiac congenital anomalies had been noted previously in this patient.

Emergency Redo Mitral Valve Replacement Immediately after Caesarean Section.

Surgery for heart diseases during pregnancy, especially necessitating cardiopulmonary bypass, is believed to trigger maternal and fetal risks and should be performed only when medical therapy has been unsuccessful to alleviate the cardiac decompensation. A 33-year-old pregnant woman in her 33rd week of gestation was admitted to our hospital. She had rheumatic mitral valvular stenosis and had undergone mitral valve replacement (MVR) with a mechanical prosthesis 11 years earlier in another center. Echocardiography revealed a thrombotic mass obstructing the leaflets of the mechanical mitral valve. Emergency redo bioprosthetic MVR concomitant with caesarean section was performed uneventfully. Both mother and baby were discharged in good condition.

Single Stage Repair for Aortic Coarctation associated with Intracardiac Defects Using Extra-Anatomic Bypass Graft in Adults.

BACKGROUND AND OBJECTIVES: Coarctation of the aorta in adulthood is generally associated with other cardiovascular disorders requiring surgical management. An extra anatomic bypass grafting from the ascending to descending aorta by posterior pericardial approach via median sternotomy could be a reasonable single stage surgical strategy for these patients. SUBJECTS AND METHODS: Seven male patients aged between 14-41 years underwent an extra anatomic bypass grafting for coarctation repair concomitantly with the surgical management of the associated cardiovascular disorders via median sternotomy. Preoperative mean systolic arterial blood pressure was 161.8±24.5 mmHg, although the patients were under treatment of different combinations of antihypertensive agents. Additional surgical procedures were: aortic valve replacement (n=4), ventricular septal defect (VSD) closure (n=2), ascending aortic replacement (n=3) and Bentall procedure (n=1). None of our patients have been previously diagnosed or operated on for coarctation. Data were evaluated during their hospital stay and in post-operative follow-up. RESULTS: The post-operative course was uneventful in all but one patient was re-operated on due to bleeding. There was neither mortality nor significant morbidity during the in-hospital period and all patients were discharged within 5-9 (mean: 6.3±1.5) days. The mean follow up period was 71.83±23 months (range: 23-95 months). Unfortunately one of our patients could not be contacted for a follow up period because of invalid personal data. CONCLUSION: Coarctation of the aorta in adulthood associated with other cardiovascular disorders can be operated on simultaneously via an extra anatomic bypass grafting technique with low morbidity and mortality.

Coronary artery bypass grafting in the awake patient: three years' experience in 137 patients.

OBJECTIVE: Our experience with 137 patients operated on without general anesthesia is reviewed to explore the validity of our surgical strategy. METHODS: Between October 1998 and January 2002, 137 patients underwent coronary artery bypass grafting with high thoracic epidural anesthesia. There were 47 female and 90 male patients, ranging in age from 37 to 92 years (mean, 68 +/- 12 years). Two patients underwent reoperation. Nineteen patients had contraindications for general anesthesia. Target vessels involved were the left anterior descending artery in 122, the right coronary artery in 6, the left anterior descending artery plus right coronary artery in 7, and the left anterior descending artery plus circumflex artery in 2 patients. Coronary artery bypass was performed through limited access in 74 patients (H-graft in 42 and rib cage lifting in 32 patients) and through a median sternotomy in 63 patients. Cardiopulmonary bypass was not used. RESULTS: In 39 (28.4%) patients pneumothorax was observed during surgical intervention. There was no mortality. Of the 137 patients, 132 (96.3%) completed the procedure awake. In 58 patients the intensive care unit was not used. Eight patients were discharged from the hospital on the day of their operation. Mean length of hospitalization was 1 day (range, 0-3 days). One hundred thirty-one patients were followed up for a period of 3 months and 3 years after their operations, and 94.7% of the patients were symptom free. Control angiograms were obtained in 41 patients. Graft patency was 100%, with one radial artery graft spasm. CONCLUSIONS: Our initial experience confirms the feasibility and safety of performing coronary artery bypass grafting in the conscious patient without general anesthesia. Further study is required to define the possible extent and limitations of this strategy.

Left main coronary disease: improved early outcomes after off-pump coronary artery bypass grafting in high-risk patients.

BACKGROUND: Left main coronary artery (LMCA) stenosis is a risk factor in coronary artery bypass grafting (CABG). Although improved outcomes of off-pump CABG have been well documented, LMCA stenosis is often perceived as a contraindicationfor off-pump CABG. In this study, we compared on-pump and off-pump techniques in high-risk patients with LMCA disease. AIM: Documentation of safety and feasibility of off-pump CABG in patients with LMCA disease. METHODS: One hundred ninty nine patients with LMCA disease and a EuroScore ≥ 5 were operated upon between 2007 and 2010. One hundred patients (Group I) were operated upon using off-pump techniques, while 99 (Group II) were operated upon using conventional on-pump techniques. Perioperative variables and outcomes at first six months were compared. RESULTS: Despite higher mean age and EuroScore (70.9 ± 4.8 vs. 65.6 ± 7.9, p < 0.001, and 6.09 ± 0.8 vs. 5.31 ± 0.68,p < 0.001, respectively), and lower ejection fraction (41.4 ± 7.3 vs. 49.0 ± 6.2, p < 0.001), hospital mortality (1% vs. 6.1%,p = 0.065), postoperative inotropic support (9% vs. 48.4%, p < 0.001), blood loss (680.6 ± 265.0 vs. 847.2 ± 382, p < 0.001) and transfusions of blood (0.57 ± 0.79 U vs. 1.49 ± 0.82 U, p < 0.001), and hospital stay (6.57 ± 2.04 vs. 7.68 ± 3.44,p = 0.006) were lower in Group I. In both groups, mean number of distal anastomoses and completeness of revascularisation were similar. CONCLUSIONS: Using the off-pump technique is safe and improves postoperative early outcomes in high-risk patients with LMCA disease.

Epidural anesthesia versus general anesthesia in patients undergoing minimally invasive direct coronary artery bypass surgery.

OBJECTIVE: Minimally invasive direct coronary artery bypass (MIDCAB) surgery in the awake patient with epidural anesthesia had been previously reported. However, there is no prospective randomized study comparing MIDCAB surgery with epidural anesthesia versus general anesthesia. METHODS: The study was conducted as a prospective and randomized study. Between January 2002 and May 2003, 76 patients were randomly assigned into either MIDCAB under general anesthesia (GA Group) or MIDCAB under epidural anesthesia (EA Group). The EA Group patients did not receive concomitant general anesthesia and they were conscious throughout the procedure. All patients had a left internal thoracic artery to left anterior descending coronary artery bypass using the same MIDCAB techniques. There were 42 patients in the GA Group and 34 patients in the EA Group. For statistical analysis, unpaired t-test for independent samples was used for comparison of continuous variables, and Pearson Chi-Square test was used for comparison of discrete variables. RESULTS: The demographic characteristics of the groups were similar. There was no mortality or major morbidity in both groups. The EA Group patients had lower arterial oxygen saturations (93.3+/- 3.2% versus 97.4+/- 1.3%, p<0.001) and higher partial carbon dioxide pressures (45.8+/- 3.6 mmHg versus 41.5+/- 2.5 mmHg, p<0.001), but these were not clinically significant. The EA Group patients had significantly less intensive care unit (ICU) (5.5+/- 6.5 hours versus 18.2+/- 4.8 hours, p<0.001) and hospital stay periods (31.4+/- 20.7 hours versus 58.6+/- 17.9 hours, p<0.001), as well as significantly less postoperative pain (visual analog score 1.06+/-0.6 versus 2.3+/-0.6, p<0.001) and blood loss (184.2+/- 169.0 ml versus 371.7+/- 315.3 ml, p<0.001). There was no any difference in regard to patient satisfaction after the procedure between the two groups. Long -term results were equally satisfactory in both groups. CONCLUSION: It can be concluded that, similar surgical results can be achieved by MIDCAB surgery with general or epidural anesthesia. Although epidural anesthesia has no impact on the degree of patient satisfaction after the procedure, it yields significantly shorter ICU and hospital stay periods, which may result in more efficient use of hospital resources.

Facile stabilization and exposure techniques in off-pump coronary bypass surgery.

Off-pump coronary artery bypass grafting can not be performed without adequate stabilization and exposure techniques. Although most of the commercially available systems provide effective stabilization and exposure, their use were generally deemed time consuming and cumbersome. Achieving the same and even better results with simple traction sutures has led to the abandonment of commercially available systems. Although not a primary concern, the radial suture traction technique is also extremely cost efficient.