Influence of preoperative and intraoperative factors on recovery after aortic root surgery.

OBJECTIVE: To determine the influence of intraoperative factors relative to preoperative risk factors on recovery after aortic root replacement (ARR). METHODS: Retrospective review of baseline and intraoperative characteristics was performed of 822 patients at our Aortic Center from 2005 to 2019. Inclusion criteria were all patients age 18 and older who underwent ARR at our institution from 2005 to 2019. The primary endpoint was the aggregate outcome of "failure to achieve uneventful recovery (FUR)," as previously defined. RESULTS: In total, 207 (25%) patients experienced FUR. The following preoperative and intraoperative variables were significantly associated with FUR in the multivariable analysis: cardiopulmonary bypass time (OR 1.01, 95% CI 1.01-1.02) open chest management (OR 5.67, 95% CI 2.65-12.1), ejection fraction (OR 1.03, 95% CI 1.01-1.04), chronic kidney disease > stage 3a (OR 2.37, 95% CI 1.54-3.63), bicuspid aortic valve (OR 1.54, 95% CI 1.21-1.96), and female sex (OR 1.30, 95% CI 1.06-1.61). Cardiopulmonary bypass time and open chest management were among the top three partial R2 contributors to the logistic regression model variance. CONCLUSIONS: These findings suggest efficacy in using intraoperative parameters to predict postoperative outcomes after ARR.

A Knife Penetrating the Right Ventricle, Interventricular Septum, and 2 Valves: A Case Report.

Penetrating chest trauma may result in significant intracardiac injury. A traumatic ventricular septal defect is a rare complication that requires surgical management, particularly if heart failure ensues. We report a case of delayed repair of an outlet-type ventricular septal defect and perforation of the aortic and pulmonary valve leaflets following a stab wound. This report highlights diagnostic and surgical considerations and also presents an opportunity to review the conotruncal anatomy, which may be relatively unfamiliar to many adult cardiac surgeons.

Outcomes After Anatomic Versus Physiologic Repair of Congenitally Corrected Transposition of the Great Arteries: A Systematic Review and Meta-Analysis.

Surgical treatment for congenitally corrected transposition of the great arteries is widely debated, with both physiologic repair and anatomic repair holding advantages and disadvantages. This meta-analysis, which includes 44 total studies consisting of 1857 patients, compares mortality at different time points (operative, in-hospital, and post-discharge), reoperation rates, and postoperative ventricular dysfunction between these two categories of procedures. Although anatomic and physiologic repair had similar operative and in-hospital mortality, anatomic repair patients had significantly less post-discharge mortality (6.1% vs 9.7%; P = .006), lower reoperation rates (17.9% vs 20.6%; P < .001), and less postoperative ventricular dysfunction (16% vs 43%; P < .001). When anatomic repair patients were subdivided into those who had atrial and arterial switch versus those who had atrial switch with Rastelli, the double switch group had significantly lower in-hospital mortality (4.3% vs 7.6%; P = .026) and reoperation rates (15.6% vs 25.9%; P < .001). The results of this meta-analysis suggest a protective benefit of favoring anatomic repair over physiologic repair.

Identification of a pathway for electron uptake in Shewanella oneidensis.

Extracellular electron transfer (EET) could enable electron uptake into microbial metabolism for the synthesis of complex, energy dense organic molecules from CO2 and renewable electricity1-6. Theoretically EET could do this with an efficiency comparable to H2-oxidation7,8 but without the need for a volatile intermediate and the problems it causes for scale up9. However, significant gaps remain in understanding the mechanism and genetics of electron uptake. For example, studies of electron uptake in electroactive microbes have shown a role for the Mtr EET complex in the electroactive microbe Shewanella oneidensis MR-110-14, though there is substantial variation in the magnitude of effect deletion of these genes has depending on the terminal electron acceptor used. This speaks to the potential for previously uncharacterized and/or differentially utilized genes involved in electron uptake. To address this, we screened gene disruption mutants for 3667 genes, representing ≈99% of all nonessential genes, from the S. oneidensis whole genome knockout collection using a redox dye oxidation assay. Confirmation of electron uptake using electrochemical testing allowed us to identify five genes from S. oneidensis that are indispensable for electron uptake from a cathode. Knockout of each gene eliminates extracellular electron uptake, yet in four of the five cases produces no significant defect in electron donation to an anode. This result highlights both distinct electron uptake components and an electronic connection between aerobic and anaerobic electron transport chains that allow electrons from the reversible EET machinery to be coupled to different respiratory processes in S. oneidensis. Homologs to these genes across many different genera suggesting that electron uptake by EET coupled to respiration could be widespread. These gene discoveries provide a foundation for: studying this phenotype in exotic metal-oxidizing microbes, genetic optimization of electron uptake in S. oneidensis; and genetically engineering electron uptake into a highly tractable host like E. coli to complement recent advances in synthetic CO2 fixation15.

Rapid curation of gene disruption collections using Knockout Sudoku.

Knockout Sudoku is a method for the construction of whole-genome knockout collections for a wide range of microorganisms with as little as 3 weeks of dedicated labor and at a cost of ∼$10,000 for a collection for a single organism. The method uses manual 4D combinatorial pooling, next-generation sequencing, and a Bayesian inference algorithm to rapidly process and then accurately annotate the extremely large progenitor transposon insertion mutant collections needed to achieve saturating coverage of complex microbial genomes. This method is ∼100× faster and 30× lower in cost than the next comparable method (In-seq) for annotating transposon mutant collections by combinatorial pooling and next-generation sequencing. This method facilitates the rapid, algorithmically guided condensation and curation of the progenitor collection into a high-quality, nonredundant collection that is suitable for rapid genetic screening and gene discovery.

Rapid construction of a whole-genome transposon insertion collection for Shewanella oneidensis by Knockout Sudoku.

Whole-genome knockout collections are invaluable for connecting gene sequence to function, yet traditionally, their construction has required an extraordinary technical effort. Here we report a method for the construction and purification of a curated whole-genome collection of single-gene transposon disruption mutants termed Knockout Sudoku. Using simple combinatorial pooling, a highly oversampled collection of mutants is condensed into a next-generation sequencing library in a single day, a 30- to 100-fold improvement over prior methods. The identities of the mutants in the collection are then solved by a probabilistic algorithm that uses internal self-consistency within the sequencing data set, followed by rapid algorithmically guided condensation to a minimal representative set of mutants, validation, and curation. Starting from a progenitor collection of 39,918 mutants, we compile a quality-controlled knockout collection of the electroactive microbe Shewanella oneidensis MR-1 containing representatives for 3,667 genes that is functionally validated by high-throughput kinetic measurements of quinone reduction.