Ahmet Baris Durukan

Hydroxyethyl starch 6%, 130/0.4 vs. a balanced crystalloid solution in cardiopulmonary bypass priming: a randomized, prospective study

BackgroundSince the advent of cardiopulmonary bypass, many efforts have been made to avoid the complications related with it. Any component of the pump participates in occurrence of these adverse events, one of which is the type of prime solution. In this study, we aimed to compare the effects of 6% hydroxyethyl starch 130/0.4 with a commonly used balanced electrolyte solution on postoperative outcomes following coronary bypass surgery.MethodsTwo hundred patients undergoing elective coronary bypass surgery were prospectively studied. The patients were randomized in to two groups. First group received a balanced electrolyte solution and the second group received 6% hydoxyethyl starch 130/0.4 as prime solution. The postoperative outcomes of the patients were studied.ResultsThe mean age of the patients was 61.81 ± 10.12 in the crystalloid group whereas 61.52 ± 9.29 in the HES group. There were 77 male patients in crystalloid group and 74 in HES group. 6% hydroxyethyl starch 130/0.4 did not have any detrimental effects on renal and pulmonary functions. The intensive care unit stay and postoperative hospital length of stay were shorter in hydroxyethyl starch group (p < 0.05 for each). Hydroxyethyl starch did not increase postoperative blood loss, amount of blood and fresh frozen plasma used, but it decreased platelet concentrate requirement. It did not have any effect on occurrence of post-coronary bypass atrial fibrillation (p > 0.05).Conclusions6% hydroxyethyl starch 130/0.4 when used as a prime solution did not adversely affect postoperative outcomes including renal functions and postoperative blood transfusion following coronary bypass surgery.

Comparison of effects of epidural bupivacaine and intravenous meperidine analgesia on patient recovery following elective abdominal aortic surgery

Background The efficacy of epidural anesthesia and analgesia in management of perioperative stress has been established. Perioperative pain management strategies decrease surgical complications and aid recovery. In this study, we aimed to document and compare the efficacy of epidural bupivacaine and intravenous meperidine on recovery of patients with elective abdominal aortic surgery performed under general anesthesia. Material/Methods Patients undergoing elective abdominal aortic surgery between February 2009 and November 2011 were studied prospectively. Patients were randomized into epidural bupivacaine (n=40) and intravenous meperidine (n=40) groups regarding postoperative analgesia strategy. The preoperative demographic characteristics, perioperative outcomes, postoperative adverse effects of analgesia strategy, time to initiate oral intake, sedation scores, visual analogue scale results, and mobility scores were compared. Results The mean ages of the patients were 61.7±8.1 in the epidural group and 59.4±9.7 in the intravenous group (p>0.05). The preoperative demographic characteristics of the patients were comparable between the groups. There were no statistically significant differences between groups regarding anesthesia times, intubation times, intensive care unit stay, hospital length of stay, postoperative vomiting, and postoperative cardiac, renal, and cerebral complications. Postoperative nausea was more prevalent in the meperidine group (p<0.05). In the epidural group, time to begin oral intake was shorter, sedation scores and visual analogue scale results were lower, and mobility scores were higher (p<0.05 each). Conclusions Epidural analgesia allowed earlier recovery compared to intravenous analgesia in patients undergoing elective abdominal aortic surgery, but did not affect postoperative outcomes and complications.

Evaluation of Skill-Acquisition Process in Mitral Valve Repair Techniques: A Simulation-Based Study

INTRODUCTION Increased patient awareness, duty-hour restrictions, escalating costs, and time constraints in the operating room have revolutionized surgical education. A bovine heart model was designed for training in mitral valve repair procedures. In this article, we aimed to share our experience with this model and to test the validity of simulation with respect to skill acquisition during the training course. METHODS After reviewing instructional video recordings of mitral valve repair techniques, 5 junior residents (first and second year) and 5 senior residents (year 4 or higher), who had no experience in mitral valve repair surgery previously, performed mitral valve repair techniques on bovine heart model in a three-month period. Nine different internet videos demonstrating surgical techniques were watched prior to performance in each case. Different text books were studied before the study course. Following repair in each case, the left ventricle of each bovine heart was statically pressurized, the coaptation depth was measured, and the regurgitation (if any) was scored. Each performance was recorded. At the end of the study, video records were evaluated in a blind fashion by 3 different surgeons experienced in mitral valve repair techniques. The monthly scores obtained were statistically analyzed. RESULTS The mean coaptation depth values measured on a monthly basis were as follows: 2.75±0.63, 4.90±0.91, and 6.55±0.88 for the junior residents and 4.30±0.65, 5.45±0.68, and 7.00±0.64mm for the senior residents. Regurgitation scores noted were 2.20±0.52, 1.65±0.58, and 0.10±0.30 for the junior residents and 1.50±0.60, 0.65±0.67, and 0.70±0.65 for the senior residents During the study period, the practice improved in terms of the aforementioned parameters in both groups (p<0.05). CONCLUSIONS This simulation model of mitral valve repair helped in skill acquisition on monthly basis in both resident groups.

Ventilation during cardiopulmonary bypass did not attenuate inflammatory response or affect postoperative outcomes.

Introduction Cardiopulmonary bypass causes a series of inflammatory events that have adverse effects on the outcome. The release of cytokines, including interleukins, plays a key role in the pathophysiology of the process. Simultaneously, cessation of ventilation and pulmonary blood flow contribute to ischaemia–reperfusion injury in the lungs when reperfusion is maintained. Collapse of the lungs during cardiopulmonary bypass leads to postoperative atelectasis, which correlates with the amount of intrapulmonary shunt. Atelectasis also causes post-perfusion lung injury. In this study, we aimed to document the effects of continued low-frequency ventilation on the inflammatory response following cardiopulmonary bypass and on outcomes, particularly pulmonary function. Methods Fifty-nine patients subjected to elective coronary bypass surgery were prospectively randomised to two groups, continuous ventilation (5 ml/kg tidal volume, 5/min frequency, zero end-expiratory pressure) and no ventilation, during cardiopulmonary bypass. Serum interleukins 6, 8 and 10 (as inflammatory markers), and serum lactate (as a marker for pulmonary injury) levels were studied, and alveolar–arterial oxygen gradient measurements were made after the induction of anaesthesia, and immediately, one and six hours after the discontinuation of cardiopulmonary bypass. Results There were 29 patients in the non-ventilated and 30 in the continuously ventilated groups. The pre-operative demographics and intra-operative characteristics of the patients were comparable. The serum levels of interleukin 6 (IL-6) increased with time, and levels were higher in the non-ventilated group only immediately after discontinuation of cardiopulmonary bypass. IL-8 levels significantly increased only in the non-ventilated group, but the levels did not differ between the groups. Serum levels of IL-10 and lactate also increased with time, and levels of both were higher in the non-ventilated group only immediately after the discontinuation of cardiopulmonary bypass. Alveolar–arterial oxygen gradient measurements were higher in the non-ventilated group, except for six hours after the discontinuation of cardiopulmonary bypass. The intubation time, length of stay in intensive care unit and hospital, postoperative adverse events and mortality rates were not different between the groups. Conclusion Despite higher cytokine and lactate levels and alveolar–arterial oxygen gradients in specific time periods, an attenuation in the inflammatory response following cardiopulmonary bypass due to low-frequency, low-tidal volume ventilation could not be documented. Clinical parameters concerning pulmonary and other major system functions and occurrence of postoperative adverse events were not affected by continuous ventilation.

May toxicity of amiodarone be prevented by antioxidants? A cell-culture study

BackgroundAtrial Fibrillation is the most common arrhythmia encountered following cardiac surgery. The most commonly administered drug used in treatment and prophylaxis is amiodarone which has several toxic effects on major organ functions. There are few clinical data concerning prevention of toxic effects and there is no routinely suggested agent. The aim of this study is to document the cytotoxic effects of amiodarone on cell culture media and compare the cytoprotective effects of commonly used antioxidant agents.MethodsL929 mouse fibroblast cell line was cultured and 100,000 cells/well-plate were obtained. First group of cells were treated with increasing concentrations of amiodarone (20 to 180 μM) alone. Second and third group of cells were incubated with one-fold equimolar dose of vitamin C and N-acetyl cysteine prior to amiodarone exposure. The viability of cells were measured by MTT assay and the cytoprotective effect of each agent was compared.ResultsThe cytotoxicity of amiodarone was significant with concentrations of 100 μM and more. The viabilities of both vitamin C and N-acetyl cysteine treated cells were higher compared to untreated cells.ConclusionsVitamin C and N-acetyl cysteine are commonly used in the clinical setting for different purposes in context of their known antioxidant actions. Their role in prevention of amiodarone induced cytotoxicity is not fully documented. The study fully demonstrates the cytoprotective role of both agents in amiodarone induced cytotoxicity on cell culture media; more pronounced with vitamin C in some concentrations. The findings may be projectile for further clinical studies.

Efficacy of thermoreactive nitinol clip implantation in reconstruction of sternal dehiscence.

BACKGROUND Sternal dehiscence is a severe complication of open heart surgery. Reinforced wiring, a system of reinforced sternal closure, fixation of a rigid plate, and implantation of thermoreactive nitinol clips (TRC) are some surgical procedures used. The aim of this study was to evaluate the role of TRC for secondary sternal reconstruction. METHODS Of 1198 patients who underwent their operations via median sternotomy in 2 separate medical centers, sternal dehiscence was observed in 16 patients overall (1.33%). The mean (SD) age of the patients was 64.06 ± 9.18 years (range, 40-77 years). Sternal dehiscence was diagnosed in all patients between the fifth and 30th postoperative days. RESULTS TRC were implanted in all of the patients who developed sternal dehiscence (16 patients). One patient developed severe respiratory failure, became ventilator dependent, and died from pneumonia on postoperative day 24. The other 15 patients were discharged without complications. Postoperative follow-up of the surviving patients revealed adequate and satisfactory sternal stability. CONCLUSION Implantation of TRC is an effective and easy method for fixing the sternum and can be performed rapidly and securely.

Obesity is still a risk factor in coronary artery bypass surgery.

OBJECTIVE Even with the improvements in surgical techniques and perioperative care, obesity is still a risk factor for occurrence of adverse events following cardiac surgery. In this observational, retrospective study, we aimed to document the effects of obesity on surgical outcomes in patients undergoing coronary artery bypass surgery and find out the effects of improvements in cardiac surgery. METHODS Between January 2011 and March 2013, isolated coronary artery bypass surgery was performed on 790 patients. The body mass index values of the patients were calculated and patients were divided into two groups; below 30 were classified as non-obese group whereas above 30 were classified as obese group. The odds ratio was obtained by using univariate analysis in order to document the effects of obesity on outcomes. RESULTS There were 548 (69.3%) patients in non-obese group, whereas 242 (30.7%) patients in obese group. The cardiopulmonary bypass (80.47±23.58 vs. 80.89±28.46, p=0.449) and aortic clamp times (54.13±16.60 vs. 54.19±19.85, p=0.511) and number of bypass grafts (3.09±1.02 vs. 2.96±1.00, p=0.11) were comparable between the groups. The mean number of fresh frozen plasma used was higher in obese patients (1.37±1.75 vs. 1.48±4.63, p=0.02). Intubation time was higher in obese patients (10.57±6.87 vs. 12.71±35.31, p=0.014). Total amount of postoperative drainage was higher in non-obese patients (766.77±472.27 vs. 648.72±371.39, p<0.001). The superficial infection/mediastenitis (0.4% vs. 2.5%, p=0.012), dehiscence (0.2% vs. 3.7%, p<0.001) and postoperative renal failure rates (4.7% vs. 8.7%, p=0.031) were higher in obese patients. The incidence of atrial fibrillation was lower in obese patients (19.7% vs. 12.8%, p=0.019). The mortality (0.5% vs. 1.7%, p=0.210) and postoperative stroke rates (1.1% vs. 0.8%, p=1.000) were similar in both groups. CONCLUSION We documented that obesity is still a risk factor for occurrence of postoperative adverse events. We believe that improved perioperative care together with meticulous regimens can improve postoperative outcomes in patients undergoing coronary artery bypass surgery.

Can valved mitral prosthesis be implanted within all kinds of the mitral annuloplasty rings

This article has been accepted for publication and undergone full peer review but has not beenthrough the copyediting, typesetting, pagination and proofreading process which may lead todifferences between this version and the Version of Record. Please cite this article as an ‘Accepted Article’, doi: 10.1002/ccd.24553

Does the anatomy of mitral paravalvular leakage increase the risk of device embolization in percutenous treatment modalities

The publication by Guler et al. [1] highlights a very problematic area in valvular surgery, the treatment of paravalvular leakage (PVL). They successfully treated mitral PVL transapically in a highrisk patient with an Amplatzer duct occluder device. They avoided all the known complications of redo surgery and the additional risks that might be brought by the comorbidities of the patient. The relation of the PVL with the hinge points of the prosthetic valve was very well emphasized, which is one of the most important determinants of procedural success rates. They also used three-dimensional transoesophageal echocardiography and demonstrated the procedure with excellent pictures. In this valuable report, there is a particular topic we would like to discuss. We know that mitral PVL has a detrimental course, especially compared with aortic PVL (16 ± 8 vs 70 ± 12% event-free survival rates in 8 years) [2]. This finding mandates immediate therapeutic intervention. In percutenous modalities of PVL occlusion, there is no real rim-like atrial septum. The anatomy may increase the tendency for residual leakages after the first occluder deployment. In addition, this strategy, particularly in the aortic position, may cause a new PVL in the anterior or posterior aspect of the device, which may require a second or third occluder implantation and even embolization after first occluder implantation. Therefore, the size of the connector that connects both discs should be of the same diameter as the defect. Sriratanaviriyakul et al. [3] reported a similar case in which they had to implant a second occluder device. So, it should be emphasized that, due to anatomical features, size matters in occluder device treatment of PVLs to prevent secondary leakages and possible embolization. Because, as the number of implanted occluder devices increase due to unfavorable anatomy, the risk of embolization will also increase. Embolized occluder devices, even in simple secundum atrial septal defects, increase the mortality 20-fold compared with elective surgery [4]. In conclusion, we believe that interventional treatment modalities of PVL will save patients’ lives with decreased adverse event rates. We would like to congratulate the authors for their success and thank them for sharing their experience with the readers.

The fanfolding modification for removing chest tube clogging after cardiac surgery

Karimov et al. [1] emphasize an interesting subject ignored by surgeons in many aspects compared with surgical procedures. However, when not followed seriously, chest tube (CT) clogging can result in catastrophic complications [2, 3]. We congratulate the authors to draw attention to CT drainage, which is as important as ‘operative planning’. Duncan and Erickson [4] state that ‘When the full length of CTs was stripped (135 cm), intrathoracic pressure increased to −400 cmH2O (=294 mmHg) (whereas 5 cm of tubing resulted in a mean pressure of −87 cmH2O (=63.9 mmHg))’. However, it may not be clinically applicable. Because when the internal volume of 135-cm-long CTs with inner diameter of 0.952 cm (3/8 inch) is measured, its volume is determined to be no more than 130 ml. According to Pascal’s Law, if a U-tube is filled with water and subsequently, the air at the top of the one arm is evacuated by a piston, the height difference between two arms represents suction pressure. The same principle can be applied to chest drainage system (CDS). Namely, if the reservoir of the CDS is completely filled with water and 130 ml of air is evacuated from the connector end of CT, the height of water column within the CT is measured about 120 cmH2O, which is much less than 400 cmH2O. Likewise, if a 5-cm-long tube is stripped, the evacuated volume is 4.4 ml, creating a suction pressure of 4.06 cmH2O (=2.9 mmHg) in the thoracic cavity. Briefly, it can be said that such high suction pressures cannot be created by stripping/milking (S/M). Otherwise, the clinical implications of high negative suction pressure created by S/M would have been observed, since the pressure change in the thoracic cavity may not transient as the authors declared in the study [1]. The supporting point is that the CDS uses an under water seal which cannot allow flow through the thoracic cavity after S/M. It was suggested in the systematic Cochrane review that techniques, including stripping, milking and fanfolding, used for removing clots from tubes are not superior to each other [5]. The fanfolding technique involves folding sections of the tube over each other and squeezing [5]. According to our clinical experience, we would like to talk about the ‘Fanfolding modification’. In this technique, the tube is clamped distally before fanfolding, subsequently the fanfolded segment is released suddenly after squeezing and the clamp is removed. The manoeuvre is continued until oscillation is approved, especially in pericardial CT. Cardiac tamponade has never been observed with the manoeuvre at the intensive care duty during our residency course ( 1640 cases in a 6-years period). While avoiding volume changes in the chest, the main effect is the removal of clot and maintaining the oscillation for intact flow to the reservoir. Although the modification is clearly beneficial, the more sophisticated systems described by the co-authors [6] are quite good, and would gain wide acceptance by many surgeons.