Difference Between Cardiopulmonary Bypass Time and Aortic Cross-Clamping Time as a Predictor of Complications After Coronary Artery Bypass Grafting

ABSTRACT Introduction: Along with cardiopulmonary bypass time, aortic cross-clamping time is directly related to the risk of complications after heart surgery. The influence of the time difference between cardiopulmonary bypass and cross-clamping times (TDC-C) remains poorly understood. Objective: To assess the impact of cardiopulmonary bypass time in relation to cross-clamping time on immediate results after coronary artery bypass grafting in the Registro Paulista de Cirurgia Cardiovascular (REPLICCAR) II. Methods: Analysis of 3,090 patients included in REPLICCAR II database was performed. The Society of Thoracic Surgeons outcomes were evaluated (mortality, kidney failure, deep wound infection, reoperation, cerebrovascular accident, and prolonged ventilation time). A cutoff point was adopted, from which the increase of this difference would affect each outcome. Results: After a cutoff point determination, all patients were divided into Group 1 (cardiopulmonary bypass time < 140 min., TDC-C < 30 min.), Group 2 (cardiopulmonary bypass time < 140 min., TDC-C > 30 min.), Group 3 (cardiopulmonary bypass time > 140 min., TDC-C < 30 min.), and Group 4 (cardiopulmonary bypass time > 140 min., TDC-C > 30 min.). After univariate logistic regression, Group 2 showed significant association with reoperation (odds ratio: 1.64, 95% confidence interval: 1.01-2.66), stroke (odds ratio: 3.85, 95% confidence interval: 1.99-7.63), kidney failure (odds ratio: 1.90, 95% confidence interval: 1.32-2.74), and in-hospital mortality (odds ratio: 2.17, 95% confidence interval: 1.30-3.60). Conclusion: TDC-C serves as a predictive factor for complications following coronary artery bypass grafting. We strongly recommend that future studies incorporate this metric to improve the prediction of complications.

Performance Evaluation of Geometrically Different Pediatric Arterial Cannulae in a Pediatric Cardiopulmonary Bypass Model

ABSTRACT Objective: To define a reference chart comparing pressure drop vs. flow generated by a set of arterial cannulae currently utilized in cardiopulmonary bypass conditions in pediatric surgery. Methods: Cannulae from two manufacturers were selected considering their design and outer and inner diameters. Cannula performance was evaluated in terms of pressure drop vs. flow during simulated cardiopulmonary bypass conditions. The experimental circuits consisted of a Jostra HL-20 roller pump, a Quadrox-i pediatric oxygenator (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set. The circuit was primed with lactated Ringer's solution only (first condition) and with human packed red blood cells added (second condition) to achieve a hematocrit of 30%. Cannula sizes 8 to 16 Fr were inserted into the cardiopulmonary bypass circuit with a "Y" connector. The flow was adjusted in 100 ml/min increments within typical flow ranges for each cannula. Pre-cannula and post-cannula pressures were measured to calculate the pressure drop. Results: Utilizing a pressure drop limit of 100 mmHg, our results suggest a recommended flow limit of 500, 900, 1400, 2600, and 3100 mL/min for Braile arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, respectively. For Medtronic DLP arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, the recommended flow limit is 600, 1100, 1700, 2700, and 3300 mL/min, respectively. Conclusion: This study reinforces discrepancies in pressure drop between cannulae of the same diameter supplied by different manufacturers and the importance of independent translational research to evaluate components' performance.

Financial Impact of Deep Sternal Wound Infections After Coronary Surgery: A Microcosting Analysis

ABSTRACT Introduction: Deep sternal wound infections (DSWI) are so serious and costly that hospital services continue to strive to control and prevent these outcomes. Microcosting is the more accurate approach in economic healthcare evaluation, but there are no studies in this field applying this method to compare DSWI after isolated coronary artery bypass grafting (CABG). This study aims to evaluate the incremental risk-adjusted costs of DSWI on isolated CABG. Methods: This is a retrospective, single-center observational cohort study with a propensity score matching for infected and non-infected patients to compare incremental risk-adjusted costs between groups. Data to homogeneity sample was obtained from a multicentric database, REPLICCAR II, and additional sources of information about costs were achieved with the electronic hospital system (Si3). Inflation variation and dollar quotation in the study period were corrected using the General Market Price Index. Groups were compared using analysis of variance, and multiple linear regression was performed to evaluate the cost drivers related to the event. Results: As expected, infections were costly; deep infection increased the costs by 152% and mediastinitis by 188%. Groups differed among hospital stay, exams, medications, and multidisciplinary labor, and hospital stay costs were the most critical cost driver. Conclusion: In summary, our results demonstrate the incremental costs of a detailed microcosting evaluation of infections on CABG patients in São Paulo, Brazil. Hospital stay was an important cost driver identified, demonstrating the importance of evaluating patients' characteristics and managing risks for a faster, safer, and more effective discharge.

Severe and Moderate Primary Graft Dysfunction in Adult Heart Recipients

ABSTRACT Introduction: The aims of this study were to determine the incidence of severe and moderate primary graft dysfunction (PGD) in our center, to identify, retrospectively, donors' and recipients' risk factors for PGD development, and to evaluate the impact of PGD within 30 days after heart transplantation. Methods: Donors' and recipients' medical records of 64 consecutive adult cardiac transplantations performed between January 2016 and June 2017 were reviewed. The International Society for Heart and Lung Transplantation (ISHLT) criteria were used to diagnose moderate and severe PGD. Associations of risk factors for combined moderate/severe PGD were assessed with appropriate statistical analyses. Results: Sixty-four patients underwent heart transplantation in this period. Twelve recipients (18.7%) developed severe or moderate PGD. Development of PGD was associated with previous donor cardiopulmonary resuscitation and a history of prior heart surgery in the recipient (P=0.01 and P=0.02, respectively). The 30-day in hospital mortality was similar in both PGD and non-PGD patients. Conclusion: The use of the ISHLT criteria for PGD is important to identify potential risk factor. The development of PGD did not affect short-term survival in our study. More studies should be done to better understand the pathophysiology of PGD.

Nonatherosclerotic Giant Right Coronary Artery Aneurysm

Abstract We present an unusual case of a 67-year-old woman with an incidental finding of a cardiac mass on a chest computed tomography. Coronary angiotomography confirmed the diagnosis of right coronary artery aneurysm, with 5.7×5.7 cm. The patient underwent aneurysm resection and coronary bypass surgery, with subsequent histologic study suggestive of arteritis sequelae. Giant coronary artery aneurysms have a high risk of complications and aneurysm exclusion must be beneficial. This is a rare condition that can also be part of a systemic inflammatory disease.

Preoperative Neutrophil-Lymphocyte Ratio Can Predict Outcomes for Patients Undergoing Tetralogy of Fallot Repair

Abstract Introduction: Elevated neutrophil-lymphocyte ratio (NLR) has been associated with poorer outcomes in cyanotic patients undergoing single ventricle palliation. Little is known about this biomarker on patients with tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. Our objective is to study the impact of preoperative NLR on outcomes of TOF patients undergoing total repair. Methods: This retrospective study included 116 consecutive patients between January 2014 and December 2018. Preoperative NLR was measured from the last complete blood count test before the surgery. Using the cutoff value of 0.80, according to the receiver-operating characteristic (ROC) curve, the sample was divided into two groups (NLR < 0.80 and ≥ 0.80). The primary endpoint was hospital length of stay (LOS). Results: ROC curves showed that higher preoperative NLR was associated with longer hospital LOS, with an area under the curve of 0.801±0.040 (95% confidence interval 0.722 - 0.879; P<0.001). High preoperative NLR was also associated with long intensive care unit (ICU) LOS (P=0.035). Preoperative NLR predicted longer hospital LOS with a sensitivity of 63% and a specificity of 81.4%. Conclusion: Higher preoperative NLR was associated with long ICU and hospital LOS in patients undergoing TOF repair.

Translation and Validation of the Boston Technical Performance Score in a Developing Country

Abstract Introduction: The Technical Performance Score (TPS) was developed and subsequently refined at the Boston Children's Hospital. Our objective was to translate and validate its application in a developing country. Methods: The score was translated into the Portuguese language and approved by the TPS authors. Subsequently, we studied 1,030 surgeries from June 2018 to October 2020. TPS could not be assigned in 58 surgeries, and these were excluded. Surgical risk score was evaluated using Risk Adjustment in Congenital Heart Surgery (or RACHS-1). The impact of TPS on outcomes was studied using multivariable linear and logistic regression adjusting for important perioperative covariates. Results: Median age and weight were 2.2 (interquartile range [IQR] = 0.5-13) years and 10.8 (IQR = 5.6-40) kilograms, respectively. In-hospital mortality was 6.58% (n=64), and postoperative complications occurred in 19.7% (n=192) of the cases. TPS was categorized as 1 in 359 cases (37%), 2 in 464 (47.7%), and 3 in 149 (15.3%). Multivariable analysis identified TPS class 3 as a predictor of longer hospital stay (coefficient: 6.6; standard error: 2.2; P=0.003), higher number of complications (odds ratio [OR]: 1.84; 95% confidence interval [CI]: 1.1-3; P=0.01), and higher mortality (OR: 3.2; 95% CI: 1.4-7; P=0.004). Conclusion: TPS translated into the Portuguese language was validated and showed to be able to predict higher mortality, complication rate, and prolonged postoperative hospital stay in a high-volume Latin-American congenital heart surgery program. TPS is generalizable and can be used as an outcome assessment tool in resource diverse settings.

Applicability of the Disruptions in Surgery Index in the Cardiovascular Management Scenarios - A Marker for Developing Functionally Efficient Teams

Abstract Introduction: To support the development of practices and guidelines that might help to reduce adverse events related to human factors, we aimed to study the response and perception by members of a cardiovascular surgery team of various error-driven or adverse features that might arise in the operating room (OR). Methods: A previously validated Disruptions in Surgery Index (DiSI) questionnaire was completed by individuals working together in a cardiovascular surgical unit. Results were submitted to reliability analysis by calculating the Cronbach's alpha coefficient. Non-parametric Kruskal-Wallis test and Dunn's post-test were performed to estimate differences in perceptions of adverse events or outcomes between the groups (surgeons, nurses, anesthesiologists, and technicians). P<0.05 was considered statistically significant. Results: Cronbach's alpha reliability coefficients showed consistency within the recommended range for all disruption types assessed in DiSI: an individual's skill (0.85), OR environment (0.88), communication (0.81), situational awareness (0.92), patient-related disruption (0.89), team cohesion (0.83), and organizational disruption (0.83). Nurses (27.4%) demonstrated significantly higher perception of disruptions than surgeons (25.4%), anesthetists (23.3%), and technicians (23.0%) (P=0.005). Study participants were more observant of their colleagues' disruptive behaviors than their own (P=0.0001). Conclusion: Our results revealed that there is a tendency among participants to hold a positive self-perception position. DiSI appears to be a reliable and useful tool to assess surgical disruptions in cardiovascular OR teams, identifying negative features that might imperil teamwork and safety in the OR. And human factors training interventions are available to develop team skills and improve safety and efficiency in the cardiovascular OR.

Pericardial-Peritoneal Window as an Alternative Treatment for Large and Recurrent Pericardial Effusion Post-Pericardiotomy

Abstract Introduction: The presence of mild to moderate pericardial effusion after cardiac surgery is common and oral medical therapy is usually able to treat it. Larger effusions are less frequent and surgical intervention is usually necessary. However, there are some rare cases of large effusions that are recurrent even after intervention and become challenging to treat. Methods: We describe the case of a patient submitted to coronary artery bypass grafting (CABG) without any intraoperative complications, who was regularly discharged from the hospital. She was referred to our emergency department twice after surgery with large pericardial effusion that was drained. Even after those two interventions and with adequate oral medication, the large effusion recurred. Results: During follow-up, the patient had her symptoms resolved, with no need for further hospital admission. Her echocardiograms after the last intervention showed no pericardial effusion. The present surgical technique demonstrated to be easy to perform, thus it should be considered as a treatment option for these rare cases of large and repetitive effusions, which do not respond to the traditional methods. Conclusions: In challenging cases of recurrent and large pericardial effusions, the pericardial-peritoneal window is an alternative surgical technique that brings clinical improvement and diminishes the risk of cardiac tamponade.

Treatment and Chest Reconstruction for Mediastinitis Following Sternotomy for Cardiac Surgery at the Heart Institute of the University of São Paulo Medical School

Abstract This study presents the method used for chest reconstruction and treatment of mediastinitis following cardiac surgery at the Heart Institute of the University of São Paulo Medical School. After infection control with antibiotic therapy associated with aggressive surgical debridement and negative pressure wound therapy, chest reconstruction is performed using flaps. The advantages and disadvantages of negative pressure wound therapy are discussed, as well as options for flap-based chest reconstruction according to the characteristics of the patient and sternum. Further studies are needed to provide evidence to support the decisions when facing this great challenge.

Impact of COVID-19 Pandemic in a Brazilian High-Volume Aortic Center

Abstract Introduction: The coronavirus disease 2019 (COVID-19) pandemic brought an unprecedented lack of control of what was to come. The intent of this document is to provide a balance of how much was ceased to be done for patients with aortic disease, to assess the mortality of these patients, and to show what happened to those who became COVID-19 positive during their hospitalization. Methods: From April 1st to July 31st 2020, the worst period of the pandemic in São Paulo, Brazil, the Institute's aortic surgical patients operated on were evaluated and those were compared with patients operated during the same period in 2019. Results: In 2019, 88 surgeries were performed; most of them were elective (66 [75%]), 10 were urgent, and 12 were emergency surgeries. In 2020, during the COVID-19 pandemic, we operated on only 31 patients, being 74.2% non-elective surgeries (P<0,001). There was a higher mortality for patients operated on during the pandemic surge of COVID-19 (P<0,001), but it was not specifically related to infected patients. Conclusion: The COVID-19 pandemic had an impact on surgical volume and outcome of patients with aortic disease, although it did not directly increase mortality.

Brazilian single-center experience with aortic root replacement in 448 patients: what is the best technique?

Abstract Introduction: The objective of this study was to evaluate whether a surgery with the use of valved conduit is capable of leading to better immediate and late results than those obtained by the valve-sparing aortic root reconstruction technique. Methods: Between January 2002 and June 2016, 448 patients underwent aortic root reconstruction. These were divided into three groups according to the technique used: 319 (71.2%) patients received mechanical valved conduits, 49 (10.9%) received biological valved conduits, and 80 (17.9%) underwent the valve-sparing aortic root reconstruction technique. The results were examined by univariate and multivariate analyses of Cox proportional hazards models with multiple logistic regression. Results: The hospital mortality rate was 7.5%. The mortality rates were 8.2%, 12%, and 2.5% in the mechanical valved conduit, biological valved conduit, and aortic valve-sparing groups, respectively, with no significant difference between groups (P=0.1). Thromboembolic complications and reoperation-free survival were also similar (P=0.169 and P=0.688). However, valve-sparing aortic root replacement was superior in terms of long-term survival (P<0.001), hemorrhagic-free survival (P<0.001), and endocarditis-free survival (P=0.048). Multivariate analysis showed that the following aspects had an impact on mortality: age > 70 years (P<0.001; hazard ratio [HR] 1.05), preoperative acute kidney injury (P<0.0042; HR 2.9), diagnosis of dissection (P<0.01; HR 2.0), previous cardiac surgery (P<0.027; HR 2.3), associated coronary artery bypass grafting (P<0.038; HR 1.8), reoperation for postoperative tamponade (P<0.004; HR 2.2) and postoperative acute kidney injury (P<0.02; HR 3.35). Conclusion: Valve-sparing technique seems to be the operation of choice, whenever possible, for aortic root reconstruction.

Heterotopic heart transplantation as a left ventricular biological assistance: a new two-stage method proposal

Abstract Since Barnard's first heterotopic heart transplant in 1974, Copeland's method has been the greatest contribution to heterotopic transplants but has the drawback of donor's right ventricular atrophy. This new method proposes a modification in the anastomosis of the superior vena cava aiming to pre-serve donor's right ventricular function by decompressing the pulmonary territory and reducing the pulmonary arterial pressure, as a biological ventricular assist device. Finally, a second intervention is proposed, where a "twist" is performed to place the donor's heart in an orthotopic position after re-moval of the native heart. A pioneering research on this method received approval from the ethics committee of the Heart Institute of São Paulo. We believe that this method has the potential to im-prove quality of life in a selected group of patients.

Coronary artery bypass graft during the covid-19 pandemic

Abstract Since the beginning of the coronavirus disease (COVID-19) pandemic, in March 2020, the number of people infected with COVID-19 worldwide increases continuously. Brazil is being followed with great concern in the international media, as it can, very soon, be the epicenter of the pandemic. Initial surgical data suggest that patients who acquire COVID-19 in the perioperative period are prone to a higher morbidity and mortality, however, evidence in cardiac surgery is still scarce. This article aims to aggregate to the growing evidence suggesting that perioperative infection with severe acute respiratory syndrome coronavirus 2 contributes to a more morbid evolution of the case.

Cardiac magnetic resonance analysis of mitral annular dynamics after mitral valve repair

OBJECTIVES: The aim of this study was to analyze mitral annulus (MA) dynamics using cardiac magnetic resonance (CMR) in patients with degenerative mitral insufficiency who underwent mitral valve repair (MVR). METHODS: Mitral valve imaging was performed by CMR in twenty-nine patients with degenerative mitral insufficiency who underwent MVR between July 2014 and August 2016, with quadrangular resection of the posterior leaflet without ring annuloplasty. They were prospectively followed up from the preoperative period up to 2 years postoperatively. RESULTS: We observed a significant reduction in all measurements of the MA after surgery. The mean systolic circumference of the MA was reduced from 13.28±1.95 cm to 11.50±1.59 cm, and the diastolic circumference was reduced from 12.51±2.01 cm to 10.66±2.09 cm in the immediate postoperative period, measures that remained stable 2 years after MVR (p<0.001). The mean maximum area of the MA was significantly reduced from 14.34±4.03 to 10.45±3.17 cm2 when comparing the immediate postoperative period and the 2 year follow-up (p<0.001). The same occurred with the mean minimum area of the MA, which was reduced from 12.53±3.68 cm2 to 9.23±2.84 cm2 in the same period, and this reduction was greater in the antero-posterior diameter than in the mid-lateral diameter. The mobility of the MA was preserved after surgery, ranging between 19.6% and 25.7% at 2-year follow-up. CONCLUSION: We observed a significant reduction in the MA size after MVR, with preservation of the MA mobility at the 2-year follow-up.

Impact of vacuum-assisted venous drainage on forward flow in simulated pediatric cardiopulmonary bypass circuits utilizing a centrifugal arterial pump head

Abstract Objective: To analyze the impact of vacuum-assisted venous drainage (VAVD) on arterial pump flow in a simulated pediatric cardiopulmonary bypass circuit utilizing a centrifugal pump (CP) with an external arterial filter. Methods: The simulation circuit consisted of a Quadrox-I Pediatric oxygenator, a Rotaflow CP (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set primed with Lactated Ringer's solution and packed red blood cells. Venous line pressure, reservoir pressure, and arterial flow were measured with VAVD turned off to record baseline values. Four other conditions were tested with progressively higher vacuum pressures (-20, -40, -60, and -80 mmHg) applied to the baseline cardiotomy pressure. An arterial filter was placed into the circuit and arterial flow was measured with the purge line in both open and closed positions. These trials were repeated at set arterial flow rates of 1500, 2000, and 2500 mL/min. Results: The use of progressively higher vacuum caused a reduction in effective arterial flow from 1490±0.00 to 590±0.00, from 2020±0.01 to 1220±0.00, and from 2490±0.0 to 1830±0.01 mL/min. Effective forward flow decreased with increased levels of VAVD. Conclusion: The use of VAVD reduces arterial flow when a CP is used as the main arterial pump. The reduction in the forward arterial flow increases as the vacuum level increases. The loss of forward flow is further reduced when the arterial filter purge line is kept in the recommended open position. An independent flow probe is essential to monitor pump flow during cardiopulmonary bypass.