Role Of Cardiopulmonary Bypass Research Articles

Tranexamic acid and convulsive seizures after isolated coronary artery bypass surgery: the role of cardiopulmonary bypass and renal function.

In cardiac surgical patients, tranexamic acid (TXA) has been associated with an increased risk of convulsive seizure (CS). We aimed to investigate whether in patients undergoing isolated coronary artery bypass grafting (CABG) surgery the use of cardiopulmonary bypass (CPB) impacts the risk of CS. We studied 4198 propensity score matched patients. Patients who underwent CABG surgery without CPB, received a single bolus of 1 g TXA. Patients who underwent CABG with CPB, additionally received a TXA dose of 0.5 g in the CPB prime and an infusion of 0.2 g/h until the end of CPB. The risk of CS in the CPB group and the group without CPB was 0.7% and 0.6%, respectively (risk ratio 1.08, 95% confidence interval 0.51-2.30; P > 0.99). Kidney function was significantly associated with the risk of CS (P = 0.005), the latter being highest in patients with glomerular filtration rates <30 ml/min/1.73 m2 (2.2%) and lowest in those patients with values >60 ml/min/1.73 m2 (0.4%). Our data in patients undergoing isolated CABG indicate no significant effect on CS risk by use of CPB when TXA doses of up to ∼2 g are given. However, caution regarding TXA administration is necessary in patients with renal impairment.

A Treatise on The Surgical Management and A Suggested Amendment of Surgical Classification of Left Ventricular Rupture Following Mitral Valve Replacement

The present perspective is a synthesis of 108 published investigations in the setting of different types of left ventricular rupture following mitral valve replacement (MVR). We identified 109 investigations and reviewed the clinical presentation, diagnostic modalities, surgical techniques and outcomes. Clinical presentation, roentgenography, cross-sectional transthoracic/transesophageal echocardiography and computerized tomography provided the diagnostic information and defined the causative mechanism. Magnetic resonance imaging had been used for further clarification of the native ventricular anatomy in high-risk subset of patients, undergoing non-traditional transapical off-pump mitral valve repair with neochordal implantation. In this article, we have attempted to address several concerning issues and controversies with reference to the possible causative mechanisms, preventive measures, the issue of chordal preservation during MVR, the degree of decalcification required in cases of heavily calcified mitral annulus, selection of appropriate sized prosthetic valves, the surgical importance of a small left ventricle, various techniques of repair, role of cardiopulmonary bypass and cardioplegic arrest during the repair of left ventricular rupture, the role of biodegradable epicardial tissue sealants, to repair or not to repair the atrio-ventricular groove hematoma during mitral valve surgery, and the role of intra-aortic balloon counterpulsation in the perioperative period. Additionally, we have highlighted a new type of left ventricular rupture described in the literature located between the base of the papillary muscle and the apex, which can be categorized as a complication of new technologies of mitral valve repair such as NeoChord device artificial chordal implantation. We have classified this category as type IV ventricular rupture. Overall, this review attempts to address the guidelines for different surgical approaches and techniques of repair of different types of left ventricular rupture for a successful outcome. We submit that an increased appreciation of the causative mechanisms of different types of left ventricular rupture and its prevention may well contribute to improved surgical management.

The role of cardiopulmonary bypass in lung transplantation.

The risk-benefit for utilizing cardio-pulmonary bypass (CPB) in lung transplantation (LTx) remains debatable. This study compares outcomes after LTx utilizing different CPB strategies - elective CPB vs. off-pump vs. off-pump with unplanned conversion to CPB. A total of 302 LTx performed over seven yr were divided into three groups: "off-pump" group (n = 86), "elective on-pump" group (n = 162), and "conversion" group (n = 54). The preoperative donor and recipient demographics and baseline characteristics and the postoperative outcomes were analyzed; 1:1 propensity score matching was used to identify patients operated upon using elective CPB who had risk profiles similar to those operated upon off-pump (propensity-matching 1) as well as those emergently converted from off-pump to CPB (propensity-matching 2). Preoperative group demographic characteristics were comparable; however, the "off-pump" patient group was significantly older. The "conversion" group had a significantly greater number of patients with primary pulmonary hypertension, pulmonary fibrosis, preoperative mechanical ventilation, and preoperative extracorporeal life support (ECLS). Postoperatively, patients from the "conversion" group had significantly poorer PaO2 /FiO2 ratios upon arrival in intensive care unit (ICU) and at 24, 48, and 72 h postoperatively, and they required more prolonged ventilation, longer ICU admission, and they experienced an increased need for ECLS than the other groups. Overall, cumulative survival at one, two, and three yr was significantly worse in patients from the "conversion" group compared to the "off-pump" and "elective on-pump" groups - 61.9% vs. 94.4% vs. 86.9%, 54.4% vs. 90.6% vs. 79.5% and 39.8% vs. 78.1% vs. 74.3%, respectively (p < 0.001). The "off-pump" group had significantly better PaO2 /FiO2 ratios, and a significantly shorter duration of ventilation, ICU stay, and hospital length of stay when compared to the propensity-matched "elective on-pump" group. There were no statistically significant differences in postoperative outcomes and overall survival between the "converted" group and the propensity-matched "elective on-pump" group. Despite segregation of unplanned CPB conversion cases from elective on-pump cases, patients with comparable preoperative demographic/risk profiles demonstrated better early postoperative outcomes and, possibly, an improved early survival with an off-pump strategy. A considerable proportion of high-risk patients require intraoperative conversion from off-pump to CPB, and this seems associated with suboptimal outcomes; however, there is no significant benefit to employing an elective on-pump strategy over emergent conversion in the high-risk group.

Böbrek Hücreli Karsinomda Cerrahi Tedavi, Kardiyopulmoner Baypasın Hayati Rolü

Böbrek Hücreli Karsinomda Cerrahi Tedavi, Kardiyopulmoner Baypasın Hayati Rolü

Reply to Koestenberger and Ravekes

We would like to thank Koestenberger et al. [1] for their comments regarding our manuscript titled ‘Disparity in right vs left ventricular recovery during follow-up after ventricular septal defect correction in children’ [2]. We fully agree with Koestenberger et al. [1] that it would be interesting to gain further knowledge regarding ventricular performance in patients with different subtypes of ventricular septal defects (VSDs). The location of the VSD and implanted patch and its relation to the tricuspid valve ring may certainly influence right ventricular (RV) free wall motion. Both tricuspid annular plane systolic excursion (TAPSE) and RV peak systolic tissue Doppler imaging velocity (S0) are assessed at the base of the RV free wall, close to the tricuspid valve ring. Accordingly, both TAPSE and RV S0 could be different in patients with different subtypes of VSDs. Hence, we appreciate the suggestion made by Koestenberger et al. [1] to calculate the z scores of TAPSE and RV S0, as previously defined [3, 4], to shed further light on the subtype analysis. The calculation of preoperative z scores yielded a mean ± standard deviation of TAPSE of 0.9 ± 2.3 and a mean RV S0 z score of 0.6 ± 1.5. One day postoperatively, z scores significantly decreased, displaying a mean TAPSE z score of −5.7 ± 1.3 and a mean RV S0 z score of −4.5 ± 1.2. At medium-term follow-up, z scores were still low, with a mean TAPSE z score of −1.6 ± 1.4 and RV S0 z score of −1.5 ± 0.9. Similar to previous results, one-way analysis of variance of these z scores did not reveal significant differences between subtypes of VSD patients preoperatively or at medium-term follow-up. Yet, considering the small number of patients and relatively large standard deviations of z scores, a lack of statistical power could still be the cause of this absence. Accordingly, these additional analyses could not shed further light on the differences between subtypes. However, current z score calculations do further validate the conclusion of our manuscript, of a persistent impairment of RV performance after surgery for a VSD. In a previous study by our group, including patients with a variety of congenital heart defects, a similar decrease in RV performance following surgery was observed [5]. Furthermore, a longer aortic cross-clamp time was associated with a lower RV S0 in this study. These results emphasize the detrimental role of cardiopulmonary bypass in ventricular deterioration after surgery and highlight the importance of follow-up of RV performance after surgery. Hence, we join Koestenberger et al. [1] in their hope for routine RV function analysis in postoperative VSD patients.

Noncardiac Surgery

Noncardiac Surgery

Invited Commentary

Invited Commentary

Resuscitation After Prolonged Cardiac Arrest: Role of Cardiopulmonary Bypass and Systemic Hyperkalemia

The purpose of this study was to determine (1) the role of emergency cardiopulmonary bypass (CPB) after prolonged cardiac arrest and failed cardiopulmonary resuscitation, and (2) the use of systemic hyperkalemia during CPB to convert intractable ventricular fibrillation (VF). Thirty-one pigs (34 +/- 2 kg) underwent 15 minutes of cardiac arrest after induced VF, followed by 10 minutes of cardiopulmonary resuscitation-advanced life support. Peripheral CPB was used if cardiopulmonary resuscitation failed to restore stable circulation. Damage was assessed by evaluating hemodynamics, biochemical variables (creatine kinase-MB, neuron-specific enolase), neurologic deficit score, and brain magnetic resonance imaging. Cardiopulmonary resuscitation alone was successful in only 19% (6 of 31 pigs). Cardiopulmonary bypass was initiated in 81% of animals (25 of 31 pigs) either for hypotension (5 of 25 pigs) or intractable VF (20 of 25 pigs). Defibrillation was successful in 7 of 20 animals during the first 10 minutes after initiating CPB. Ventricular fibrillation persisted more than 10 minutes in 13 of 20 pigs, and animals were treated either with repeated defibrillation (6 of 13 pigs) or with a potassium bolus (7 of 13 pigs) to induce transient cardiac arrest. Overall survival at 24 hours was 84% with cardiopulmonary resuscitation (100% of pigs with hypotension; 71% in CPB-VF < 10 minutes). Despite CPB, fatal myocardial failure occurred after VF duration of more than 10 minutes in all pigs treated with electrical defibrillation, whereas hyperkalemia allowed 100% cardioversion and 86% survival. Biochemical variables remained elevated in all groups. Similarly, severe brain injury was present in all animals as confirmed by neurologic deficit score (197 +/- 10) and magnetic resonance imaging. Emergency CPB after prolonged cardiac arrest improves survival and allows systemic hyperkalemia to convert intractable VF, but fails to reduce neurologic damage.

Randomized controlled trial on the cardioprotective effect of bone marrow cells in patients undergoing coronary bypass graft surgery

This randomized study investigates whether bone marrow cells (BMCs) can reduce ischaemic injury during cardiac surgery. Forty-four elective coronary artery bypass grafting patients were randomized to control group or BMCs group (whereby autologous BMCs were administered with each dose of cardioplegia antegradely into the coronaries). Troponin I and CK-MB were measured during the first 48 h after surgery and were not significantly different between the control and BMCs groups. The role of cardiopulmonary bypass (CPB) on the cardioprotective effects of BMCs was also studied using an in vitro model of stimulated ischaemia and reoxygenation on right atrial appendages obtained from controls either before or 10 min after the initiation of CPB. Bone marrow cells significantly reduced myocardial injury in muscles obtained prior to CPB. This effect was comparable with ischaemic preconditioning (IP), although their combination did not afford additional benefit. However, when muscles were harvested after CPB, myocardial injury in the ischaemic group alone was less, and BMCs or IP did not exert further protection. Bone marrow cells did not afford additional benefit when used as an additive to cardioplegia during CPB. However, BMCs offer cardioprotection as potent as IP, when the heart is not subjected to stress, such as CPB, that per se can precondition the myocardium.

Role of Cardiopulmonary Bypass and Arrested Heart Status in the Early Cell Distribution after Intracoronary Infusion of Bone Marrow Stromal Cells

Systemic distribution of bone marrow stromal cells (BMSCs) after intracoronary infusion (ICI) and the role of cardiopulmonary bypass (CPB) in cell distribution still remain unclear. This study was designed o analyze the cell distribution after ICI in variations of heart status in a swine myocardial infarction model. After inducing a myocardial infarction, iron oxide labeled male cells (1 x 10(8)) were infused through the coronary artery of the beating swine heart in Group 1. In Group 2, CPB was set up and then the same volume of cells was infused after cardioplegic arrest. In Groups 3 and 4, the animals underwent either beating or arrested ICI with the same volume of saline. Three days later, cell distribution was assessed by T2* change with magnetic resonance imaging and sex-determining region on Y-chromosome with quantitive polymerase chain reaction. Only a few transplanted cells were localized in the heart and no difference was found between Groups 1 and 2. The majority of BMSCs would be trapped in extracardial organs, and more cells resided in the spleen in arrested heart status. The majority of BMSCs transplanted by ICI would be entrapped by the extracardial organs. The arrested heart with CPB during ICI does not favor more cell retention in the injured myocardium. The optimal approach of delivery of BMSCs still needs further investigation.

Cerebral injury during paediatric heart surgery: perfusion issues.

Suboptimal neurodevelopmental outcome is common in children who have congenital heart disease. Its aetiology is often multifactorial. This review focuses on the role of cardiopulmonary bypass. Hypothermia is the mainstay of cerebral protection. Low flow and regional low flow are preferred to deep hypothermic circulatory arrest in many situations. Cooling and rewarming, aortopulmonary collaterals, pH, air emboli, the systemic inflammatory response, haematocrit, oxygenation, glucose and ultrafiltration can influence neurodevelopmental outcome. Although no pharmacological agents have been shown to have a beneficial effect on neurodevelopmental outcome in clinical practice in children, animal work on the use of steroids several hours before surgery is encouraging.

Protection of the human heart with ischemic preconditioning during cardiac surgery: role of cardiopulmonary bypass

Objective Studies on the effects of ischemic preconditioning in the human heart have yielded conflicting results and therefore remain controversial. This study investigated whether ischemic preconditioning was able to protect against myocardial tissue damage in patients undergoing coronary artery surgery with cardiopulmonary bypass and on the beating heart. Methods A total of 120 patients were studied and divided into 3 groups: group I: cardiopulmonary bypass with intermittent crossclamp fibrillation; group II: cardiopulmonary bypass with cardioplegic arrest using cold blood cardioplegia; group III: surgery on the beating heart. In each group (n = 40), patients were randomly subdivided (n = 20/subgroup) into control and preconditioning groups (1 cycle of 5 minutes of ischemia/5 minutes reperfusion before intervention). Ischemic preconditioning was induced by clamping the ascending aorta in groups I and II or by clamping the coronary artery in group III. Serial venous blood levels of troponin T were analyzed before surgery and at 1, 4, 8, 24, and 48 hours after termination of ischemia. In addition, in vitro studies using right atrial specimens obtained before the institution of cardiopulmonary bypass, and then again 10 minutes after initiation of bypass, were performed. The specimens were equilibrated for 30 minutes before being allocated to 1 of the following 2 groups (n = 6 per group): (1) ischemia alone (90 minutes of ischemia followed by 120 minutes of reoxygenation) or (2) preconditioning with 5 minutes of ischemia and 5 minutes of reoxygenation before the long ischemic insult. Creatine kinase leakage (U/g wet weight) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction (mmol/l per gram wet weight), an index of cell viability, were assessed at the end of the experiment. Results There were no perioperative myocardial infarctions or deaths in any of the groups studied. The total release of troponin T was similar in groups I and II (patients undergoing surgery with cardiopulmonary bypass) and in the release profile; they were unaffected by ischemic preconditioning. In contrast, the total troponin T release for the first 48 hours was significantly reduced by ischemic preconditioning in group III (patients undergoing surgery without cardiopulmonary bypass) from 3.1 ± 0.1 to 2.1 ± 0.2 ng · h · mL. Furthermore, the release profile that peaked at 8 hours in the control group shifted to the left at 1 hour. In the in vitro studies, the atrial muscles obtained before cardiopulmonary bypass were protected by ischemic preconditioning (creatine kinase = 2.6 ± 0.2 and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction = 152 ± 24 vs creatine kinase = 5.4 ± 0.6 and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction = 87 ± 16 in controls; P < .05); however, the muscles obtained 10 minutes after initiation of cardiopulmonary bypass were already protected (creatine kinase = 0.8 ± 0.1 and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction = 316 ± 38), and ischemic preconditioning did not result in further improvements. Conclusions Ischemic preconditioning is protective in patients undergoing coronary artery surgery on the beating heart without the use of cardiopulmonary bypass, but it offers no additional benefit when associated with bypass regardless of the mode of cardioprotection used, because cardiopulmonary bypass per se induces preconditioning.

The role of cardiopulmonary bypass and surfactant in pulmonary decompensation after surgery for congenital heart disease

J Thorac Cardiovasc Surg 1999;117:1025-6

Concomitant cardiac and pulmonary operation: the role of cardiopulmonary bypass.

To assess the safety and efficacy of concomitant pulmonary resection and cardiac operation requiring cardiopulmonary bypass, the records of 19 patients were reviewed. Eighteen patients (94.7%) presented with cardiac symptoms and were found to have pulmonary pathology of indeterminate etiology. Pulmonary resections were performed through a median sternotomy in all but 1 patient, who underwent posterolateral thoracotomy and right middle lobectomy after repositioning because dense adhesions prevented adequate dissection through the initial incision. A total of 24 resections were performed. Sixteen (66.7%) were performed on cardiopulmonary bypass. Six wedge resections (25.0%) were performed before bypass. Two lobectomies (8.3%) were performed after infusion of protamine sulfate. Nine patients (47.4%) had benign pathology, 7 (36.8%) had primary carcinoma, and 3 (15.8%) had metastatic disease. Bleeding complications occurred in 15.8% of patients (3/19). There was 1 perioperative death (5.3%), which was due to adult respiratory distress syndrome after intraoperative hemorrhage followed lobectomy for bullous disease. Another patient required lateral extension of the sternotomy during an episode of exsanguinating intraparenchymal pulmonary hemorrhage, which resulted in lobectomy, as well as costochondral and sternal osteomyelitis. A third patient required exploration for bleeding at the staple line. Postoperative complications occurred in 7 patients (36.8%) and were predominantly respiratory (5/7, 71.4%) (p = 0.006). The median postoperative hospitalization was 15 days. Although comparison of patients who underwent pulmonary resection during bypass with those who had resection either before heparinization or after protamine infusion showed no significant difference with respect to age, incidence of malignancy, operation performed, complications, postoperative hospitalization, or survival, this was probably due to the small number of patients in the study.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical significance of elevated CSF and plasma histamine in cerebral aneurysm surgery utilizing cardiopulmonary bypass with total circulatory arrest.

Recently there has been a renewed interest in the neurosurgical treatment of large cerebral aneurysms and AV malformations utilising cardiopulmonary bypass (CPB) and total circulatory arrest (TCA). However, the differing tolerance limits of coagulation and bleeding, pH control and fluid constraint are difficult to reconcile. Although clinical assessment, electro encephalogram (EEG) and intracranial pressure-monitoring assist in identification of cerebral damage, CPB and TCA inflict their own penalties with resultant uncertainty in post-operative neurological evaluation, and producing difficulties in interpretation and management. Additionally, an unanswered question is, to what extent the known cardiac and cerebral effects of circulating histamine might influence the post-circulatory arrest recovery in these patients, and whether this would further compromise the neurological result. We report our experience of 9 such cases who underwent this procedure, and were able to achieve a satisfactory neurological result in 7 patients with differing lesions. During the operation both CSF (from the open cranium) and blood (from the right internal jugular vein) were sampled at intervals for subsequent plasma histamine estimation. Despite markedly elevated histamine levels during CPB and TCA, this was not associated with an unfavourable neurological outcome. These early findings have given us encouragement to the useful role of CPB and TCA in these complex neurosurgical presentations, and raise interesting questions about the clinical importance of histamine-evoked cerebral ischaemia that has been demonstrated in experimental models.

Effect of Cardiopulmonary Bypass on Postoperative Nutrition of Cardiac Surgery Patients

Introduction: Nutrition is an important factor for recovery following cardiac surgery. Most patients loose appetite and have reduced nutrition following cardiac surgery. Several factors including pain, anxiety, medications, whole body inflammatory response, Cardiopulmonary bypass (CPB) have role in postoperative anorexia and reduced nutrition. Objective: Objective of this study is to find out the role of CPB in postoperative anorexia and nutrition. Methodology: This prospective study was conducted at NICVD. 30 randomly selected adult patients who had undergone open heart surgical procedures were compared to same number of closed heart surgery patients. The daily food intake was calculated from the ICU data-sheets and calorie value obtained. The values were compared between the open and closed heart surgery patients. Results: It was noted that the open heart surgery patients took significantly less amount of food and calorie compared to the closed heart surgery patients. Conclusion: Open heart surgery is a situation where post operative nutrition plays a very significant role in patient's recovery. But unfortunately there is a tendency of the patient's taking low calorie intake for various reasons. This may have a critical role postoperatively. So adequate measures should be adopted to ensure proper postoperative nutrition following open heart surgery. DOI: 10.3329/bmj.v38i2.3574 Bangladesh Medical Journal 38(2) 2009 53-55