Open thoracic surgical implantation of cardiac pacemakers in rats.

Genetic engineering and implantable bioelectronics have transformed investigations of cardiovascular physiology and disease. However, the two approaches have been difficult to combine in the same species: genetic engineering is applied primarily in rodents, and implantable devices generally require larger animal models. We recently developed several miniature cardiac bioelectronic devices suitable for mice and rats to enable the advantages of molecular tools and implantable devices to be combined. Successful implementation of these device-enabled studies requires microsurgery approaches that reliably interface bioelectronics to the beating heart with minimal disruption to native physiology. Here we describe how to perform an open thoracic surgical technique for epicardial implantation of wireless cardiac pacemakers in adult rats that has lower mortality than transvenous implantation approaches. In addition, we provide the methodology for a full biocompatibility assessment of the physiological response to the implanted device. The surgical implantation procedure takes ~40 min for operators experienced in microsurgery to complete, and six to eight surgeries can be completed in 1 d. Implanted pacemakers provide programmed electrical stimulation for over 1 month. This protocol has broad applications to harness implantable bioelectronics to enable fully conscious in vivo studies of cardiovascular physiology in transgenic rodent disease models.

Risk factors for cerebrovascular accident after isolated coronary artery bypass grafting in Veterans.

BACKGROUND: Cerebrovascular accident (CVA) after coronary artery bypass grafting (CABG) is a devastating complication. Patient comorbidities and intraoperative elements contribute to the risk of CVA. The aim of this study is to identify risk factors for CVA in Veterans undergoing CABG. METHODS: Veterans undergoing isolated CABG from 2008 to 2019 were retrospectively identified using the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. Thirty-day postoperative outcomes were observed. Univariate analysis followed by multivariable logistic regression identified independent risk factors for postoperative CVA. Receiver operating characteristic diagnostics identified optimal inflection points between continuous risk factors and odds of CVA. RESULTS: Twenty-eight thousand seven hundred fifty-seven patients met inclusion criteria. Incidence of CVA was 1.1% (310 cases). In multivariate analysis, preoperative cerebrovascular disease had the strongest association with postoperative CVA (adjusted odds ratio = 2.29; p < .001). There was an inverse relationship between CVA incidence and ejection fraction (EF), with EF of 35%-39% conferring a 2.11 times higher risk compared to EF >55% (p < .001). CVA incidence was not different in on-pump versus off-pump cases; however, after 104 min or more on bypass patients had a 55% greater adjusted odds of CVA (p < .001). Other risk factors included poor kidney function, prior myocardial infarction, and intra-aortic balloon pump use. CONCLUSION: The risk of CVA after CABG is multifactorial and involves multiple organ systems, including cardiac disease, poor renal function, and cerebrovascular disease, which was the strongest contributing risk factor. Optimization of these comorbidities and time on bypass may help improve clinical outcomes and lower the risk of this devastating complication.

Racial Disparities in 30-Day Outcomes After Colorectal Surgery in an Integrated Healthcare System.

BACKGROUND: Racial disparities in colorectal surgery outcomes have been studied extensively in the USA, and access to healthcare resources may contribute to these differences. The Veterans Health Administration (VHA) is the largest integrated healthcare network in the USA with the potential for equal access care to veterans. The objective of this study is to evaluate the VHA for the presence of racial disparities in 30-day outcomes of patients that underwent colorectal resection. METHODS: Colon and rectal resections from 2008 to 2019 were reviewed retrospectively using the Veterans Affairs Surgical Quality Improvement Program database. Patients were categorized by race and ethnicity. Multivariable analysis was used to compare 30-day outcomes. Cases with "unknown/other/declined to answer" race/ethnicity were excluded. RESULTS: Thirty-six-thousand-nine-hundred-sixty-nine cases met inclusion criteria: 27,907 (75.5%) Caucasian, 6718 (18.2%) African American, 2047 (5.5%) Hispanic, and 290 (0.8%) Native American patients. There were no statistically significant differences in overall complication incidence or mortality between all cohorts. Compared to Caucasian race, African American patients had longer mean length of stay (10.7 days vs. 9.7 days; p < 0.001). Compared to Caucasian race, Hispanic patients had higher odds of pulmonary-specific complications (adjusted odds ratio with 95% confidence interval = 1.39 [1.17-1.64]; p < 0.001). CONCLUSIONS: The VHA provides the benefits of integrated healthcare and access, which may explain the improvements in racial disparities compared to existing literature. However, some racial disparities in clinical outcomes still persisted in this analysis. Further efforts beyond healthcare access are needed to mitigate disparities in colorectal surgery. CLASSIFICATIONS: [Outcomes]; [Database]; [Veterans]; [Colorectal Surgery]; [Morbidity]; [Mortality].