Slobodan Micovic

Comparison of Valve Annuloplasty and Replacement for Ischemic Mitral Valve Incompetence

OBJECTIVE Mitral incompetence is a chronic sequela of myocardial infarction. It is caused by apical displacement and tethering of the mitral valve leaflets after myocardial infarction, resulting in incomplete coaptation. The consensus is for mitral valve surgery in the presence of significant ischemic mitral regurgitation (IMR). Previously, the only option was mitral valve replacement (MVR) with a mechanical or tissue valve. The suboptimal results obtained prompted the development of several methods of mitral valve repair. Today, the most commonly used repair is undersized annuloplasty. METHODS We conducted a retrospective nonrandomized study of all patients who underwent operation for coronary artery disease and IMR between 2000 and 2006. The surgeon chose the surgical method used for the mitral valve procedure. The most commonly used procedures were restrictive mitral valve annuloplasty (MVP) and MVR with a mechanical prosthesis. We collected all pertinent preoperative, intraoperative, and early-postoperative data. We followed up with phone interviews of the patients and their relatives and with complete clinical and echocardiography examinations. RESULTS We carried out operations on 138 patients during the study period (MVR, 52 patients; MVP, 86 patients). The 2 groups had comparable demographic data and risk factors. The 2 groups were significantly different with respect to mean (+/-SD) New York Heart Association (NYHA) class (MVP, 2.72 +/- 0.62; MVR, 2.48 +/- 0.70; P < .01) and ejection fraction (MVP, 29.01% +/- 11.00%; MVR, 35.87% +/- 11.00%; P </= .01). The 30-day mortality rates for the MVR and MVP groups were significantly different (9.61% and 5.81%, respectively; P < .01). Our follow-up included 83% of the patients and continued for up to 84 months. The 2 groups showed no significant difference in mortality by the end of follow-up; however, the MVR patients had a better ejection fraction (37.79% versus 29.86%) and NYHA functional class (1.88 +/- 0.498 versus 2.36 +/- 0.564; P < .01). CONCLUSION Correcting chronic IMR with either repair or replacement produces a good mid-term survival rate (approximately 75%) for survivors in NYHA classes I and II. In our study, mortality rates for the MVP and MVR groups were similar, even though the repair group had a lower mean ejection fraction and a higher NYHA class before and after the operation. We therefore conclude that repair is superior to replacement in treating ischemic mitral insufficiency. A prospective randomized study is needed to better compare these 2 approaches.

Mitochondrial Molecular Basis of Sevoflurane and Propofol Cardioprotection in Patients Undergoing Aortic Valve Replacement with Cardiopulmonary Bypass

Background/Aims: Study elucidates and compares the mitochondrial bioenergetic-related molecular basis of sevoflurane and propofol cardioprotection during aortic valve replacement surgery due to aortic valve stenosis. Methods: Twenty-two patients were prospectively randomized in two groups regarding the anesthetic regime: sevoflurane and propofol. Hemodynamic parameters, biomarkers of cardiac injury and brain natriuretic peptide (BNP) were measured preoperatively and postoperatively. In tissue samples, taken from the interventricular septum, key mitochondrial molecules were determined by Western blot, real time PCR, as well as confocal microscopy and immunohisto- and immunocyto-chemical analysis. Results: The protein levels of cytochrome c oxidase and ATP synthase were higher in sevoflurane than in propofol group. Nevertheless, cytochrome c protein content was higher in propofol than sevoflurane receiving patients. Propofol group also showed higher protein level of connexin 43 (Cx43) than sevoflurane group. Besides, immunogold analysis showed its mitochondrial localization. The mRNA level of mtDNA and uncoupling protein (UCP2) were higher in propofol than sevoflurane patients, as well. On the other hand, there were no significant differences between groups in hemodynamic assessment, intensive care unit length of stay, troponin I and BNP level. Conclusions: Our data indicate that sevoflurane and propofol lead to cardiac protection via different mitochondrially related molecular mechanisms. It appears that sevoflurane acts regulating cytochrome c oxidase and ATP synthase, while the effects of propofol occur through regulation of cytochrome c, Cx43, mtDNA transcription and UCP2.

Simultaneous hybrid carotid stenting and coronary bypass surgery versus concomitant open carotid and coronary bypass surgery: a pilot, feasibility study

OBJECTIVES Concomitant carotid and cardiac surgery carries an increased perioperative morbidity and mortality risk. Whether the hybrid procedure of carotid artery stenting (CAS) and coronary bypass surgery decreases the risk of stroke and other complications is still unknown. The aim of this study was to assess early outcomes after simultaneous hybrid CAS and coronary bypass grafting versus open concomitant carotid and coronary bypass surgery. METHODS We included 20 patients in this study. According to the protocol, all the patients were divided into two groups: Group 1 (10 patients) with hybrid CAS and coronary bypass surgery and Group 2 (10 patients) with concomitant carotid and coronary surgery. Different preoperative, intraoperative and postoperative variables were compared. The primary end point was combined incidence of stroke and death 30 days after surgery or during initial hospitalization. The secondary end points were myocardial infarction, atrial fibrillation, blood loss and need for blood transfusion and duration of intensive care unit and hospital stay. RESULTS Groups 1 and 2 were similar in preoperative characteristics including age (65.3 ± 6.8 vs 70.7 ± 7.0, P = 0.191) New York Heart Association class (2.3 ± 0.5 vs 1.8 ± 0.7, P = 0.218), EuroSCORE (2.8 ± 2.0 vs 3.6 ± 2.3, P = 0.547), the degree of carotid stenosis (79 ± 12 vs 87 ± 13%, P = 0.224) and average left ventricular ejection fraction (44.3 ± 12.4 vs 43.4 ± 13.3%, P = 0.896). Also, the groups did not differ in intraoperative variables with an exception of extracorporeal circulation time (65.7 ± 14.1 vs 90.0 + 17.4 min, P = 0.023), which was significantly shorter in Group 1. Although rare, and without significant difference, primary end point occurred only in Group 2 (1 stroke and 1 death, 20%). There was no difference in the duration of mechanical ventilation, need for transfusion and duration of intensive care unit and hospital stay between the two groups. CONCLUSIONS Although limited by a small sample size, our results show that the hybrid procedure of carotid stenting and coronary surgery might be a good therapeutic option but further extended studies are needed to assess its real value.

Cor Triatriatum Dexter and Atrial Septal Defect in a 43-Year-Old Woman

Cor triatriatum dexter is a rare congenital heart anomaly in which a membrane divides the right atrium into 2 chambers. We report the case of a 43-year-old woman who had cor triatriatum dexter and a large atrial septal defect. During attempted percutaneous closure, the balloon disrupted the membrane and revealed that the defect had no inferior rim, precluding secure placement of an Amplatzer Septal Occluder. Surgical treatment subsequently proved to be successful. In patients with an incomplete membrane and a septal defect with well-defined rims, percutaneous treatment can be the first choice. In patients who have cor triatriatum dexter and unfavorable anatomic features or concomitant complex heart anomalies, open-heart surgery remains the gold standard for treatment.

A refined flanged Bentall technique using Valsalva tube graft: does it really wrap all of the proximal anastomosis line?

We read with great interest the article by Koshiyama et al. [1] regarding reinforcement of the proximal anastomosis during composite graft replacement of the aortic root, using one of the modifications of the Bentall and DeBono technique [2]. Modified Bentall procedures have many beneficial effects such as prevention of excessive bleeding and development of false aneurysm, avoidance of the kinking of coronary arteries, as well as reduced tension on ‘button’ coronary anastomoses. However, a major weakness in the composite graft replacement of the ascending aorta is haemostasis at the proximal suture line. A refined, flanged Bentall technique using Vasalva tube graft reported by Koshiyama et al. [1] is similar to the flanged technique reported by Yakut [3], previously. The Valsalva sinus portion of the graft is resected, leaving 10 mm in length as the flange and is everted outwards using Koshiyama’s technique [1], whether a segment (several millimetres in a length) of the proximal end of vascular graft is everted outwards to form the flange of the graft using Yakut’s technique [3]. The polypropylene running suture (3–0 or 4–0) is used to anastomose the cuff of the prosthetic valve to the bottom border of the chosen conduit. Subsequently, the flange is returned to its original position. In both techniques, the homemade composite conduit is seated on the aortic annulus, using continuous 3–0 polypropylene suture [3], or everting pledgeted 2–0 polyester sutures [1], which are passed through the flange below the sewing cuff of the prosthetic valve. Koshiyama et al. [1] stated that using 3–0 polyprolene suture to sew the flange and the margin of the residual proximal aortic wall enabled them to wrap tightly all of the proximal anastomosis line. However, as it can be easily seen on figure 1D of their manuscript [1], only the pledgets of the tied everting pledgeted 2–0 polyester sutures are covered, while the knots of these sutures are still ‘naked’, outside, on the flange, between the flange and prosthetic tube, thus leaving pinholes of the everting mattress sutures as the potential sites of bleeding. On the contrary, Chen et al. [4] modified the composite graft by adding a short skirt (which was made of a part of the distal end of the prosthetic tube) to a standard composite graft root. After the proximal end of the modified composite conduit was secured in the aortic annulus, the short skirt was sewn to the remaining native proximal aortic wall to really wrap all of the proximal anastomosis line. However, we have to point out that Copeland et al. [5] reported an elegant, easily reproducible, and efficient technique to reduce bleeding from the proximal anastomosis after the Bentall procedure. After the composite conduit is seated into the aortic annulus and the sutures are tied, an additional 3–0 polypropylene suture is used to sew the cut edge of the proximal aortic wall and the prosthetic sewing cuff or the prosthetic tube, thus reinforcing and really completely covering all of the proximal anastomosis line.

Preoperative Insight Into the Quality of Radial Artery Grafts.

We investigated the impact of preoperative ultrasonography of the forearm circulation on radial artery conduit selection. Preoperative ultrasound of the forearm circulation was performed routinely in 536 patients planned for radial artery harvesting. The safety assessment of the harvest included the following algorithm of tests: the ultrasound, the Allen test, and pulse oximetry. The quality criteria that were used to exclude a radial artery from harvesting were small size of the artery, diffuse atherosclerosis, calcifications, and severe neointimal hyperplasia. The overall rejection rate due to safety reasons was 16.4%. Seventy-one (13.2%) radial arteries did not fulfill the conduit quality criteria and consequently these arteries were not harvested. In 13.4% of radial arteries, localized arterial wall disease was found in the distal third of the artery. The distal part of the artery was discarded and the rest was used as a conduit. Our results indicate that the ultrasound provides an accurate preoperative insight into the radial artery morphology, enabling selection of the arteries with favorable morphological features.

Concomitant reconstruction of arch vessels during repair of aortic dissection.

Surgery for acute aortic dissection is challenging, especially in cases of cerebral malperfusion. Should we perform only the aortic repair, or should we also reconstruct the arch vessels when they are severely affected by the disease process? Here we present a case of acute aortic dissection with multiple tears that involved the brachiocephalic artery and caused cerebral and right upper-extremity malperfusion. The patient successfully underwent complete replacement of the brachiocephalic artery and the aortic arch during deep hypothermic circulatory arrest, with antegrade cerebral protection. We have found this technique to be safe and reproducible for use in this group of patients.

Effect of Elective Bentall Procedure on Left Ventricular Systolic Function and Functional Status: Long-Term Follow-Up in 90 patients

Because there are so few data on the long-term effects on left ventricular systolic function and functional status in patients who electively undergo Bentall procedures, we established a retrospective study group of 90 consecutive patients. This group consisted of 71 male and 19 female patients (mean age, 54 ± 10 yr) who had undergone the Bentall procedure to correct aortic valve disease and aneurysm of the ascending aorta, from 1997 through 2003 in a single tertiary-care center. We monitored these patients for a mean period of 117 ± 41 months for death, left ventricular ejection fraction and volume indices, and functional capacity as determined by New York Heart Association (NYHA) class. There were no operative deaths. The survival rate was 73.3% during follow-up. There were 10 cardiac and 13 noncardiac deaths, and 1 death of unknown cause. Echocardiography was performed before the index procedure and again after 117 ± 41 months. In surviving patients, statistically significant improvement in left ventricular ejection fraction, in comparison with preoperative values (0.49 ± 0.11 vs 0.41 ± 0.11; P <0.0001), was noted at follow-up. Similarly, we observed statistically significant reductions in left ventricular end-systolic (39.24 ± 28.7 vs 48.77 ± 28.62 mL/m(2)) and end-diastolic volumes (54.63 ± 6.97 vs 59.17 ± 8.92 mL/m(2); both P <0.0001). Most patients (53/66 [80.3%]) progressed from a higher to a lower NYHA class during the follow-up period. The Bentall procedure significantly improved long-term left ventricular systolic function and functional status in surviving patients who underwent operation on a nonemergency basis.

Consecutive Observational Study to Validate EuroSCORE II Performances on a Single-Center, Contemporary Cardiac Surgical Cohort

OBJECTIVE To compare and validate the original EuroSCORE risk stratification models with the renewed EuroSCORE II model in a contemporary cardiac surgical practice. DESIGN A consecutive observational study to validate EuroSCORE II performances, conducted as retrospective analysis of prospectively collected data. SETTING A tertiary university institute for cardiovascular diseases. PARTICIPANTS Adult patients undergoing cardiac surgery between January and December 2012. METHODS One thousand eight hundred sixty-four consecutive patients were scored preoperatively using additive and logistic EuroSCORE as well as EuroSCORE II. The discriminative power of the EuroSCORE models was tested by calculating the area under the receiver operating characteristic curve (AUC). The calibration of the models was assessed by Hosmer-Lemeshow statistics and with observed-to-expected mortality ratio. MEASUREMENTS AND MAIN RESULTS The in-hospital overall mortality was 3.65%, with predicted mortalities according to additive EuroSCORE, logistic EuroSCORE, and EuroSCORE II of 5.14%, 6.60%, and 3.51%, respectively. The observed-to-expected (O/E) mortality ratio confirmed good calibration for the entire cohort only for EuroSCORE II (1.05, 95% confidence interval 0.81 - 1.29). Hosmer-Lemeshow test confirmed overall good calibration only for additive EuroSCORE (p = 0.129). The EuroSCORE II confirmed very good discriminatory power for a prolonged intensive care unit (ICU) stay of>2 days and>5 days (AUCs>0.75). Acceptable discriminatory power was confirmed for a prolonged postoperative stay of>7 days and>12 days (AUCs>0.70). CONCLUSION EuroSCORE II confirmed very good discriminatory capacity, good calibration ability (O/E mortality ratio), and good capability to predict prolonged ICU and postoperative stays in a contemporary patient cohort undergoing cardiac surgery.

The current role of surgery in treating adult patients with patent ductus arteriosus.

OBJECTIVE Surgical closure of patent ductus arteriosus (PDA) is still required in selected adult patients. We analyzed the morphology of the anomaly and coexisting pathological findings in adult patients who were recently referred to our institute for surgical PDA repair. PATIENTS AND INTERVENTIONS Six adult PDA patients who were not considered candidates for percutaneous closure underwent surgical PDA correction. In three patients with isolated PDA, computed tomographic scan revealed short, wide, and distorted ductus. In the remainder three patients, concomitant heart or aortic disease was found. Transpulmonary approach under total cardiopulmonary bypass or hypothermic circulatory arrest was performed. RESULTS In all patients, a Dacron patch was used to close the duct. The balloon occlusion technique with normothermic cardiopulmonary bypass was performed in four patients. In one of these patients, the balloon occlusion was not feasible because of unfavorable ductal anatomy, and PDA was closed in short hypothermic circulatory arrest. In two patients with aortic aneurysm, PDA closure and aortic reconstruction were performed in deep hypothermic circulatory arrest. No significant complications occurred during postoperative course. After the mean follow-up period of 48 months, neither ductal reopening nor aneurysmal degeneration of remnant ductal tissue was found. CONCLUSION Surgical PDA closure in adults remains the treatment of choice in wide, deformed PDAs unsuitable for percutaneous closure and PDAs associated with surgical aortic or heart disease.