Pulmonary Artery Aneurysm: A Rarity and Surgical Enigma.

Given the low incidence of pulmonary artery aneurysms (PAAs), proven surgical indications do not yet exist. We present a patient with a 6.3 cm PAA who underwent an open sternotomy, pulmonary artery aneurysmectomy, and repair with an aortic homograft. We discuss surgical indications, including pain, growth in diameter, and diameter of 5.5 cm and larger. The current recommended surgical indication for the size of PAAs is based on recommendations for aortic aneurysms and observation in a small number of operable patients, highlighting the need for more discussion and reporting of this rare presentation.

Operative Teaching of Coronary Bypass and Need for Repeat Catheterization: Does it Matter Who is Sewing?

OBJECTIVE: There are no studies to date comparing the patency of coronary bypass grafts constructed by attending surgeons versus trainees and the potential consequences of any such disparities. We explored this issue by comparing the patency of individual anastomoses performed by residents versus the attending surgeon. DESIGN: We reviewed 765 continuous cases performed by a single surgeon which involved at least 1 coronary bypass anastomosis, totaling 2,173 distal anastomoses. At a median follow-up time of 36 months (interquartile range 20.5-47.3), 83 (10.9%) patients had undergone 110 cardiac catheterization procedures after their original operation for various indications. This angiographic information provided the data for our comparison cohorts. SETTING: Cardiac surgery practice within an academic setting PARTICIPANTS: Adult patient undergoing coronary bypass grafting RESULTS: Of the 83 patients that underwent repeat catheterization, 23 (27.7%) were resident cases, 25 (30.1%) were attending cases and 35 (42.2%) were mixed. There were 4/83 (4.8%) patients with angiographic evidence of internal mammary artery graft compromise of which 3/4 (75%) had been constructed by the attending surgeon. Angiographic evidence of saphenous vein graft compromise was appreciated in 16/83 (19.3%) patients of which 9/16 (56.3%) of the grafts were constructed by the attending surgeon. CONCLUSIONS: Liberal involvement of surgical trainees as primary operators in coronary revascularization cases led to equivalent rates of postoperative ischemic complications between the attending and resident groups. The outcome equivalence was also maintained when evaluated at the individual anastomosis patency level between the 2 groups. We conclude that academic programs should continue providing trainees significant experience as primary operating surgeons without fear of clinical outcome compromise.

Left atrial function and not volume predicts mid-to-late atrial fibrillation after mitral valve repair.

OBJECTIVES: Patients undergoing surgical mitral valve repair (MVr) for degenerative mitral regurgitation are at risk of even late postoperative atrial fibrillation (AF). Left atrial (LA) function has been shown superior to LA volume in evaluating the risk of AF in diverse cardiac conditions. We therefore investigated the prognostic value of LA function and volume in predicting mid-to-late postoperative AF after MVr (>30 days postoperatively). METHODS: We retrospectively identified all patients who underwent MVr for degenerative mitral regurgitation between 2012 and 2019 at our institution. Exclusion criteria were preoperative AF, concomitant procedures, re-operations, missing or insufficiently processable preoperative echocardiograms and missing follow-up. LA function and volume measurements were conducted using speckle-tracking strain echocardiographic analysis. Postoperative LA function was measured in a subgroup with sufficient postoperative echocardiograms. RESULTS: We included 251 patients, of whom 39 (15.5%) experienced AF in the mid-to-late postoperative period. Reduced LA strain parameters and more than mild preoperative tricuspid regurgitation were independently associated with mid-to-late postoperative AF. LA volume index had no association with mid-to-late postoperative AF in univariable analysis and did not improve the performance of multivariable models. Patients with mid-to-late AF exhibited diminished improvement in LA function after surgery. CONCLUSIONS: In MVr patients, LA function (but not volume) showed independent predictive value for mid-to-late postoperative AF. Including LA function into surgical decision-making and approach may identify patients who will benefit from earlier intervention with the aim to prevent irreversible LA damage with consequent risk of postoperative AF.

Prediction of operative mortality for patients undergoing cardiac surgical procedures without established risk scores.

OBJECTIVE: Current cardiac surgery risk models do not address a substantial fraction of procedures. We sought to create models to predict the risk of operative mortality for an expanded set of cases. METHODS: Four supervised machine learning models were trained using preoperative variables present in the Society of Thoracic Surgeons (STS) data set of the Massachusetts General Hospital to predict and classify operative mortality in procedures without STS risk scores. A total of 424 (5.5%) mortality events occurred out of 7745 cases. Models included logistic regression with elastic net regularization (LogReg), support vector machine, random forest (RF), and extreme gradient boosted trees (XGBoost). Model discrimination was assessed via area under the receiver operating characteristic curve (AUC), and calibration was assessed via calibration slope and expected-to-observed event ratio. External validation was performed using STS data sets from Brigham and Women's Hospital (BWH) and the Johns Hopkins Hospital (JHH). RESULTS: Models performed comparably with the highest mean AUC of 0.83 (RF) and expected-to-observed event ratio of 1.00. On external validation, the AUC was 0.81 in BWH (RF) and 0.79 in JHH (LogReg/RF). Models trained and applied on the same institution's data achieved AUCs of 0.81 (BWH: LogReg/RF/XGBoost) and 0.82 (JHH: LogReg/RF/XGBoost). CONCLUSIONS: Machine learning models trained on preoperative patient data can predict operative mortality at a high level of accuracy for cardiac surgical procedures without established risk scores. Such procedures comprise 23% of all cardiac surgical procedures nationwide. This work also highlights the value of using local institutional data to train new prediction models that account for institution-specific practices.

Induction therapy in lung transplantation: A contemporary analysis of trends and outcomes.

OBJECTIVES: We provide a contemporary consideration of long-term outcomes and trends of induction therapy use following lung transplantation in the United States. METHODS: We reviewed the United Network for Organ Sharing registry from 2006 to 2018 for first-time, adult, lung-only transplant recipients. Long-term survival was compared between induction classes (Interleukin-2 inhibitors, monoclonal or polyclonal cell-depleting agents, and no induction therapy). A 1:1 propensity score match was performed, pairing patients who received basiliximab with similar risk recipients who did not receive induction therapy. Outcomes in matched populations were compared using Cox, Kaplan-Meier and Logistic regression modeling. MEASUREMENTS AND MAIN RESULTS: 22 025 recipients were identified; 8003 (36.34%) were treated with no induction therapy, 11 045 (50.15%) with basiliximab, 1556 (7.06%) with alemtuzumab and 1421 (6.45%) with anti-thymocyte globulin. Compared with those who received no induction, patients receiving basiliximab, alemtuzumab or anti-thymocyte globulin were found on multivariable Cox-regression analyses to have lower long-term mortality (all p < .05). Following propensity score matching of basiliximab and no induction populations, analyses demonstrated a statistically significant association between basiliximab use and long- term survival (p < .001). Basiliximab was also associated with a lower risk of acute rejection (p < .001) and renal failure (p = .002). CONCLUSION: Induction therapy for lung transplant recipients-specifically basiliximab-is associated with improved long-term survival and a lower risk of renal failure or acute rejection.

Trends in Diversity in Integrated Cardiothoracic Surgery Residencies.

BACKGROUND: Integrated cardiothoracic surgery residencies began 2006 to address workforce shortages in cardiothoracic surgery. As more attention has been given to racial and gender disparities, our goal was to examine trends in diversity among integrated cardiothoracic residents. METHODS: All US accredited integrated cardiothoracic programs that had accepted residents through 2020 were included. A resident list was collected through online websites and direct institutional contact. Gender, race, and year of entry were recorded. Linear regression models were used to evaluate racial and gender trends over time. RESULTS: From 2006 through 2020, 321 residents were accepted into integrated cardiothoracic training programs. Men comprised 72% (232/321) of the cohort. The racial distribution was 66.4% White (213/321), 26.2% Asian (84/321), 5.3% Hispanic (17/321), and 2.2% African American (7/321). Over the study period the time slope for Whites was -2.95 (P < .01), indicating an approximately 3% decrease each year. The time slope for Asians was 1.60 (P < .01), whereas the time slope did not change significantly for African Americans (0.10, P = .94) or Hispanics (0.13, P = .91). Adjusting for the number of integrated programs each year as a covariate did not change trends for any race. The time slope did not change significantly over the time period for men (-0.25, P = .71). CONCLUSIONS: Gender and racial diversity have not improved over time in integrated cardiothoracic residencies. Institutions should strive to recruit medical students from underrepresented backgrounds and increase their focus on gender diversity.

Rationale and Design of the Randomized Controlled Trial of New Oral Anticoagulants Versus Warfarin for Post Cardiac Surgery Atrial Fibrillation: The NEW-AF Trial.

OBJECTIVE: This manuscript describes the rationale and design of a randomized, controlled trial comparing outcomes with Warfarin vs Novel Oral Anticoagulant (NOAC) therapy in patients with new onset atrial fibrillation after cardiac surgery. BACKGROUND: New onset atrial fibrillation commonly occurs after cardiac surgery and is associated with increased rates of stroke and mortality. in nonsurgical patients with atrial fibrillation, NOACs have been shown to confer equivalent benefits for stroke prevention with less bleeding risk and less tedious monitoring requirements compared with Warfarin. However, NOAC use has yet to be adopted widely in cardiac surgery patients. METHODS: The NEW-AF study has been designed as a pragmatic, prospective, randomized controlled trial that will compare financial, convenience and safety outcomes for patients with new onset atrial fibrillation after cardiac surgery that are treated with NOACs versus Warfarin. RESULTS: Study results may contribute to optimizing the options for stroke prophylaxis in cardiac surgery patients and catalyze more widespread application of NOAC therapy in this patient population. CONCLUSIONS: The study is ongoing and actively enrolling at the time of the publication. The trial is registered with clinicaltrials.gov under registration number NCT03702582.

Late onset atrial fibrillation in patients undergoing surgical aortic valve replacement.

OBJECTIVE: Aortic valve disease is a risk factor for atrial fibrillation (AF), and AF is associated with increased late mortality and morbidity after cardiac surgery. The evolution of alternative approaches to AF prophylaxis, including less invasive technologies and medical therapies, has altered the balance between risk and potential benefit for prophylactic intervention at the time of surgical aortic valve replacement (SAVR). Such interventions impose incremental risk, however, making an understanding of predictors of new onset AF that persists beyond the perioperative episode relevant. METHODS: We conducted a retrospective single-institution cohort analysis of patients undergoing SAVR with no history of preoperative AF (n = 1014). These patients were cross-referenced against an institutional electrocardiogram (ECG) database to identify those with ECGs 3-12 months after surgery. Logistic regression was used to identify predictors of late AF. RESULTS: Among the 401 patients (40%), who had ECGs in our institution 3-12 months after surgery, 16 (4%) had late AF. Patients with late AF were older than patients without late AF (73 vs. 65, p = .025), and underwent procedures that were more urgent/emergent (38% vs. 15%, p = .015), with higher predicted risk of mortality (2.2% vs. 1.3%, p = .012). Predictors associated with the development of late AF were advanced age, higher preoperative creatinine level and urgent/emergent surgery. CONCLUSIONS: The incidence of late AF 3-12 months after SAVR, is low. Prophylactic AF interventions at the time of SAVR may not be warranted.

The Longest Documented Postoperative Survivor of a Brock Procedure 63 Years Later.

An infant with critical pulmonary valve stenosis underwent a Brock procedure in 1957 with subsequent repair of pulmonary stenosis and an atrial septal defect at age 6. At age 17 she underwent repair for paradoxical embolization secondary to a residual atrial septal defect. She presented 54 years later with recurrent pulmonary stenosis and a symptomatic 6.2-cm pulmonary artery aneurysm repaired with a 23-mm aortic homograft. This patient is the longest reported postoperative survivor after a Brock procedure. She continues to do well 63 years after her initial surgery.

Factors Related to Survival in Low-Glomerular Filtration Rate Cohorts Undergoing Lung Transplant.

BACKGROUND: Historically, a glomerular filtration rate (GFR) of less than 50 mL/min per 1.73 m2 has been considered a contraindication to lung transplantation. Combined or sequential lung-kidney transplantation is an option for those with a GFR less than 30 mL/min per 1.73 m2. Patients with a GFR of 30 to 50 mL/min per 1.73 m2 are provided with no options for transplantation. This study explores factors associated with improved survival in patients who undergo isolated lung transplantation with a GFR of 30 to 50 mL/min per 1.73 m2. METHODS: The United Network for Organ Sharing database was queried for adult patients undergoing primary isolated lung transplantation between January 2007 and March 2018. Regression models were used to identify factors associated with improved survival in lung recipients with a preoperative GFR of 30 to 50 mL/min per 1.73 m2. The propensity score method was used to match highly performing patients (outpatient recipients aged less than 60 years) with a GFR of 30 to 50 mL/min per 1.73 m2 with patients who had a GFR greater than 50 mL/min per 1.73 m2. Kaplan-Meier, Cox, and logistic regression analyses compared outcomes in matched populations. RESULTS: A total of 21,282 lung transplantations were performed during the study period. Compared with patients with a GFR greater than 50 mL/min per 1.73 m2, survival was significantly worse for patients with a GFR of 30 to 50 mL/min per 1.73 m2. Multivariate analysis of patients with a GFR of 30 to 50 mL/min per 1.73 m2 demonstrated outpatient status and age less than 60 years to be predictive of superior survival. After propensity matching, survival of this highly performing subset with a GFR of 30 to 50 mL/min per 1.73 m2 was no different from that of patients with a normal GFR. CONCLUSIONS: Outpatient recipients aged less than 60 years represent an optimal subset of patients with a GFR of 30 to 50 mL/min per 1.73 m2. Lung transplant listing should not be declined based only on a GFR less than 50 mL/min per 1.73 m2.

Use of Surgical Simulation by Underrepresented High School Students to Address Diversity Gaps in Surgery.

Recent tragedies have displayed systemic inequities in our society. Our institution has created a program for underrepresented high school students in our surgical simulation lab. The students have responded very favorably, and their interest in a surgical career and self-confidence increased significantly.

Specialized dendritic cells induce tumor-promoting IL-10+IL-17+ FoxP3neg regulatory CD4+ T cells in pancreatic carcinoma.

The drivers and the specification of CD4+ T cell differentiation in the tumor microenvironment and their contributions to tumor immunity or tolerance are incompletely understood. Using models of pancreatic ductal adenocarcinoma (PDA), we show that a distinct subset of tumor-infiltrating dendritic cells (DC) promotes PDA growth by directing a unique TH-program. Specifically, CD11b+CD103- DC predominate in PDA, express high IL-23 and TGF-ß, and induce FoxP3neg tumor-promoting IL-10+IL-17+IFNγ+ regulatory CD4+ T cells. The balance between this distinctive TH program and canonical FoxP3+ TREGS is unaffected by pattern recognition receptor ligation and is modulated by DC expression of retinoic acid. This TH-signature is mimicked in human PDA where it is associated with immune-tolerance and diminished patient survival. Our data suggest that CD11b+CD103- DC promote CD4+ T cell tolerance in PDA which may underscore its resistance to immunotherapy.