Contemporary utilization of the axillary artery in cardiac surgery.

INTRODUCTION: The axillary artery is a reliable inflow vessel when addressing pathology of the aortic root and aortic arch that may preclude standard central cannulation strategies. This narrative review examines the use of the axillary artery in cardiac surgery. Anatomy, indications for use, cannulation strategies, and potential complications will be discussed. METHODS: A comprehensive review of the current literature was performed using PubMed, Cochrane Review, and authoritative committee guidelines. A narrative review incorporating current available evidence was undertaken. COMMENT: Use of the axillary artery in select cardiac surgical cases is reliable, reproducible, and may be preferable in certain cases involving ascending aortic pathology, reoperative surgery, porcelain aorta, access for transcatheter valve therapies, and peripheral mechanical circulatory support.

A machine learning approach to high-risk cardiac surgery risk scoring.

INTRODUCTION: In patients undergoing high-risk cardiac surgery, the uncertainty of outcome may complicate the decision process to intervene. To augment decision-making, a machine learning approach was used to determine weighted personalized factors contributing to mortality. METHODS: American College of Surgeons National Surgical Quality Improvement Program was queried for cardiac surgery patients with predicted mortality ≥10% between 2012 and 2019. Multiple machine learning models were investigated, with significant predictors ultimately used in gradient boosting machine (GBM) modeling. GBM-trained data were then used for local interpretable model-agnostic explanations (LIME) modeling to provide individual patient-specific mortality prediction. RESULTS: A total of 194 patient deaths among 1291 high-risk cardiac surgeries were included. GBM performance was superior to other model approaches. The top five factors contributing to mortality in LIME modeling were preoperative dialysis, emergent cases, Hispanic ethnicity, steroid use, and ventilator dependence. LIME results individualized patient factors with model probability and explanation of fit. CONCLUSIONS: The application of machine learning techniques provides individualized predicted mortality and identifies contributing factors in high-risk cardiac surgery. Employment of this modeling to the Society of Thoracic Surgeons database may provide individualized risk factors contributing to mortality.

Comprehensive Analysis of Stroke in the Long-Term Cohort of the MOMENTUM 3 Study.

BACKGROUND: The MOMENTUM 3 study (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) has demonstrated that the HeartMate 3 (HM3) pump is associated with reduced strokes compared with the HeartMate II (HMII) device. We now perform a comprehensive analysis of stroke events to evaluate their longitudinal occurrence, clinical correlates, patterns, and impact on outcome across the 2-year duration of support. METHODS: MOMENTUM 3 is a randomized controlled trial of the HM3 centrifugal-flow pump versus the HMII axial-flow pump in patients with advanced heart failure, regardless of the intended goal of support (bridge to transplantation or destination therapy). Baseline and postimplantation clinical correlates of stroke events were assessed with multivariable analyses. Longitudinal patterns, including device association, type of stroke (hemorrhagic versus ischemic), changing severity of impairment assessed with the modified Rankin Scale (disabling [modified Rankin Scale score >3] versus nondisabling [modified Rankin Scale score ≤3]) over time, and association with outcome, were determined. RESULTS: In 361 patients with the intended implant (189 HM3 and 172 HMII), 65 strokes (40 ischemic strokes and 25 hemorrhagic strokes) occurred in 52 patients at a median of 131 (range, 1-733) days. No difference in stroke rate was noted between 0 and 180 days of follow-up between devices. However, stroke incidence in the long-term period (181-730 days after left ventricular assist device) was 3.3 times lower for the HM3 group (HM3: 0.04 versus HMII: 0.13 events per patient-year; odds ratio, 0.23; 95% CI, 0.08-0.63; P=0.01). Treatment with the HM3 pump was the only independent predictor of lower stroke events. We found no direct association of blood pressure or antithrombotic regimens with observed stroke rates. A stroke event significantly lowered 2-year postimplantation survival regardless of subtype or initial severity of neurological impairment compared with patients without a stroke (43±12% for hemorrhagic stroke, 57±9% for ischemic stroke, 51±11% for disabling, and 51±11% for nondisabling compared with 85±2% 2-year survival for patients without stroke). CONCLUSIONS: The HM3 pump is associated with a marked reduction in stroke rates compared with the HMII device, with benefits observed in the long-term period (>6 months). The occurrence of stroke of any type (hemorrhagic and ischemic) or of any functional severity (disabling and nondisabling) is predictive of a poor 2-year clinical outcome. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov/ . Unique identifier: NCT02224755.

Mechanical cardiopulmonary resuscitation for venoarterial ECMO implantation in pulmonary embolism complicated by type B aortic dissection and retroperitoneal hemorrhage.

A patient with acute pulmonary embolism suffered cardiac arrest, received manual and mechanical cardiopulmonary resuscitation and tissue plasminogen activator before extracorporeal cardiopulmonary resuscitation was initiated. She suffered a type B aortic dissection and retroperitoneal hemorrhage secondary to resuscitation measures. This case report describes high-risk anticoagulation management for contradicting treatment goals in preparation for pulmonary embolectomy on cardiopulmonary bypass.

Percutaneous venoarterial extracorporeal membrane oxygenation as a bridge to double valve implantation in acute biventricular heart failure with profound cardiogenic shock.

A 71-year-old woman was admitted with acute hypoxic and hypercapnic respiratory failure and cardiogenic shock, secondary to acute on chronic biventricular systolic and diastolic congestive heart failure and severe aortic and mitral valve stenosis. She further presented with pulmonary hypertension and moderate-to-severe tricuspid regurgitation requiring high and increasing doses of vasopressors. The patient was percutaneously cannulated for venoarterial extracorporeal membrane oxygenation (VA-ECMO) and stabilized on ECMO, with a urine output of 17.3 L within the following 8 days. Balloon valvuloplasty and/or transcatheter aortic valve replacement were discussed but ruled out by the multidisciplinary team considering the mitral valve could not be fully addressed. Though lung function was not fully optimized, a window of opportunity was identified and used for double valve replacement on day 8 of VA-ECMO support. After a 24-hour vasoplegic period, the patient was extubated to continuous positive airway pressure and further transitioned to nasal cannula, following which she recovered well.

Positive Impact of an Aortic Center Designation.

BACKGROUND: In January 2015, we created a multidisciplinary Aortic Center with the collaboration of Vascular Surgery, Cardiac Surgery, Interventional Radiology, Anesthesia and Hospital Administration. We report the initial success of creating a Comprehensive Aortic Center. METHODS: All aortic procedures performed from January 1, 2015 until December 31, 2016 were entered into a prospectively collected database and compared with available data for 2014. Primary outcomes included the number of all aortic related procedures, transfer acceptance rate, transfer time, and proportion of elective/emergent referrals. RESULTS: The Aortic Center included 5 vascular surgeons, 2 cardiac surgeons, and 2 interventional radiologists. Workflow processes were implemented to streamline patient transfers as well as physician and operating room notification. Total aortic volume increased significantly from 162 to 261 patients. This reflected an overall 59% (P = 0.0167) increase in all aorta-related procedures. We had a 65% overall increase in transfer requests with 156% increase in acceptance of referrals and 136% drop in transfer denials (P < 0.0001). Emergent abdominal aortic cases accounted for 17% (n = 45) of our total aortic volume in 2015. The average transfer time from request to arrival decreased from 515 to 352 min, although this change was not statistically significant. We did see a significant increase in the use of air-transfers for aortic patients (P = 0.0041). Factorial analysis showed that time for transfer was affected only by air-transfer use, regardless of the year the patient was transferred. Transfer volume and volume of aortic related procedures remained stable in 2016. CONCLUSIONS: Designation as a comprehensive Aortic Center with implementation of strategic workflow systems and a culture of "no refusal of transfers" resulted in a significant increase in aortic volume for both emergent and elective aortic cases. Case volumes increased for all specialties involved in the center. Improvements in transfer center and emergency medical services communication demonstrated a trend toward more efficient transfer times. These increases and improvements were sustainable for 2 years after this designation.

Extracorporeal membrane oxygenation as a bridge to advanced heart failure therapies.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a key support modality for cardiogenic shock. The 2018 United Network for Organ Sharing (UNOS) heart transplant allocation algorithm prioritizes VA-ECMO patients. OBJECTIVE: To evaluate the role of VA-ECMO in bridging to advanced heart failure therapies. METHODS: We analyzed adult patients from the multicenter Extracorporeal Life Support Organization registry receiving VA-ECMO for cardiac support or resuscitation between 2016 and 2021 in the United States, comparing bridge-to-transplant (BTT) and non-BTT intent patients, as well as pre- vs post-2018 patients, on a wide range of demographic and clinical outcome predictors. RESULTS: Of 17,087 patients, 797 received left ventricular assist device (LVAD)/heart transplant, 7,931 died or had poor prognosis, and 8,359 had expected recovery at ECMO discontinuation. Patients supported with BTT intent had lower clinical acuity than non-BTT candidates and were more likely to receive LVAD/transplant. The proportion of patients who received VA-ECMO as BTT and received LVAD/transplant increased after 2018. Post-2018 BTT patients had significantly lower clinical acuity and higher likelihood of transplant than both post-2018 non-BTT patients and pre-2018 BTT patients. ECMO complications were associated with lower likelihood of transplant but were significantly less common post-2018 than pre-2018. CONCLUSIONS: After implementation of the 2018 UNOS allocation system, ECMO utilization as BTT or LVAD has increased, and the acuity of BTT intent patients cannulated for ECMO has decreased. There has not yet been an increase in more acute ECMO patients getting transplanted. This may partially explain the post-transplant outcomes of ECMO patients in the current era reported in UNOS.

Endovascular repair of thoracic aortoenteric fistulas.

Aortoesophageal fistula is a rare manifestation of thoracic aortic surgery or esophageal disease. We describe a patient who underwent emergent endovascular repair of an aortoesophageal fistula due to a ruptured penetrating ulcer of the descending thoracic aorta and review the literature on this subject.

Aortic Prosthetic Valve Endocarditis: Analysis of The Society of Thoracic Surgeons Database.

BACKGROUND: This study sought to characterize the current US experience of aortic prosthetic valve endocarditis (PVE) compared with native valve endocarditis (NVE). METHODS: The Society of Thoracic Surgeons Database was queried for entries of active aortic infective endocarditis (IE). Two analyses were performed: (1) trends of surgical volume and operative mortality (2011-2019); and (2) descriptive and risk-adjusted comparisons between PVE and NVE (2014-2019) using multivariable logistic regression. RESULTS: From 2011 to 2019, there was a yearly increase in the proportion of PVE (20.9% to 25.9%; P < .001) with a concurrent decrease in operative mortality (PVE, 22.5% to 10.4%; P < .001; NVE, 10.9% to 8.5%; P < .001). From 2014 to 2019, active aortic IE was identified in 9768 patients (NVE, 6842; PVE, 2926). Aortic root abscess (50.1% vs 25.2%; P < .001), aortic root replacement (50.1% vs 12.8%; P < .001), homograft implantation (27.2% vs 4.1%; P < .001), and operative mortality (12.2% vs 6.4%; P < .001) were higher in PVE. After risk adjustment, PVE (odds ratio [OR], 1.5; 95% CI,1.16-1.94; P < .01), aortic root replacement (OR, 1.49; 95% CI,1.15-1.92; P < .001), Staphylococcus aureus (OR, 1.5; 95% CI,1.23-1.82; P < .001), and unplanned revascularization (OR, 5.83; 95% CI,4.12-8.23; P < .001) or mitral valve surgery (OR, 2.29; 95% CI,1.5-3.51; P < .001) correlated with a higher operative mortality, whereas prosthesis type (P = .68) was not an independent predictor. CONCLUSIONS: IE in the United States has risen over the past decade. However, operative mortality has decreased for both PVE and NVE. PVE, extension of IE requiring aortic root replacement, and additional unplanned surgical interventions carry an elevated mortality risk. Prosthesis selection did not affect operative mortality.

Repair of Massive Stanford Type A Aortic Dissection in a Jehovah's Witness Using Bloodless Surgery.

Refusal of blood product transfusion presents a unique challenge in patients requiring major cardiac surgery. We present a case of a 45-year-old African American female Jehovah's Witness with a history of aortic dissection who presented to the emergency department with worsening back pain. Imaging revealed aneurysmal dilatation of her known Stanford type A dissection measuring 10.9 cm. A staged carotid-subclavian bypass followed by aortic valve, ascending aorta, and aortic arch replacement with debranching was performed using a bloodless strategy.

Long-term outcomes of etiology specific annuloplasty ring repair of ischemic mitral regurgitation.

BACKGROUND: Reductive annuloplasty repair of ischemic mitral regurgitation (IMR) is associated with high rates of recurrent MR, which may be improved with etiology-specific annuloplasty rings. METHODS: From October 2005 to May 2015, 128 consecutive patients underwent repair of IMR with the GeoForm ring. Clinical data was extracted from our local Society of Thoracic Surgeons database and electronic medical records. Mortality data was obtained from the Michigan State Social Security Death Index. RESULTS: The average age of patients was 65±11 years with mean pre-op left ventricular ejection fraction (LVEF) of 30%±10% and MR grade of 3.1±0.9 (0-4+). Thirty-day mortality was 4.7%, rate of renal failure 7.9%, rate of atrial fibrillation 27.3%, and no strokes were observed. Of the surviving patients, 89% (109/122) had a follow-up echocardiogram beyond 1 month with a mean echocardiographic follow-up of 59±39 months. LVEF improved from 30%±10% to 38%±14%, P<0.001) while end-diastolic (5.9±0.0 to 5.3±0.9 cm, P<0.001) and end-systolic (5.0±1.0 to 4.4±1.1 cm, P<0.001) left ventricular (LV) diameters decreased, as compared to pre-operative values. Seven patients were found to have recurrent moderate or greater IMR in follow-up to 10 years with three being due to ring dehiscence. One-, 5-, and 10-year freedom from recurrent moderate or severe IMR was 98%, 94%, and 80% respectively. One-, 5-, and 10-year survival was 91%, 77%, and 44%, respectively. CONCLUSIONS: Overall, etiology-specific ring repair of IMR was associated with low rates of recurrent MR on long-term follow-up, coupled with significant LV reverse remodeling and improvement in ejection fraction.

Primary neuroendocrine tumour of the left ventricle.

Neuroendocrine tumours are rare neoplasms typically arising in the gastrointestinal tract that may result in carcinoid syndrome and/or acquired valvular dysfunction. Herein, we present a unique case of a 68-year-old asymptomatic woman with a primary left ventricular neuroendocrine tumour.

Initial results of a thoracic aortic endovascular program: safer in high-risk patients.

Results are presented from our single-institutional experience with thoracic endovascular aortic repair to confirm that it is safe in patients with significant comorbidities. A retrospective review of all patients undergoing endovascular or open thoracic aortic repair at our institution since 2002 was performed. Main outcome measures included clinical presentation, demographics, preoperative risk factors, operative details, and clinical outcomes. The endovascular group included 37 patients (22 males), whereas the open group included 19 patients (eight males). Eight patients per group were treated emergently for trauma or rupture (22% and 42%, respectively; p=0.11). Endovascular patients were significantly older with more comorbid conditions (p<0.05). However, the overall perioperative complication rate was similar in the two groups (32.4% and 31.6%, respectively). Postoperative renal failure occurred only in four open patients (21.1% vs. 0%, p < 0.05). Operative time, ventilator days, and total length of stay were also greater for open patients (p<0.05). There was one death in the endovascular group and three in the open group (2.7% and 15.8%, respectively; p=0.07). Endovascular patients had shorter operative time and length of stay, fewer ventilator days and intensive care unit days, and fewer transfusions. Although the endovascular patients were significantly older with more comorbidities, the complication rate was similar to the open group. Also, there was a trend toward lower mortality in the endovascular group (p=0.07). Endovascular repair is the procedure of choice for treating the descending thoracic aorta in high-risk patients even in the emergent setting.

Radiographic evaluation of intussusception: utility of left-side-down decubitus view.

PURPOSE: To assess the incremental value of the left-side-down decubitus view in radiographic evaluation of ileocolic intussusception. MATERIALS AND METHODS: The institutional review board approved this retrospective investigation with waiver of informed consent. Between February 24, 2002, and January 25, 2007, 304 studies (300 patients; mean age, 1.3 years; range, 0.1-3.9 years) met the following inclusion criteria: kidney ureter bladder (KUB) and decubitus views obtained, with subsequent proof of diagnosis. Using a consensus approach, two pediatric radiologists evaluated KUB and decubitus views for four variables: (a) discrete mass and (b) small-bowel obstruction (positive criteria); (c) air or stool in ascending colon and (d) cecal air or stool (negative criteria). On the basis of these criteria, each study was graded as negative, positive, or indeterminate for intussusception. Diagnostically determinate studies and the ability to visualize or exclude intussusception were calculated to determine sensitivity and specificity. The difference between proportions was calculated, along with 95% confidence intervals. Agreement between the supine KUB view and supine KUB plus left-side-down decubitus views was tested with the McNemar test. RESULTS: Intussusception was present in 58 of 304 studies (19%). Adding the decubitus view to the KUB view increased the number of determinate studies from 110 of 304 (36.2%) to 205 of 304 (67.4%) (difference, 31.2 percentage points; P < .001). Intussusception was correctly identified with KUB view alone in 35 of 58 studies (60.3%); this value increased to 43 of 58 (74.1%) with KUB plus decubitus views (P = .0215). Intussusception was correctly excluded with the KUB view alone in 63 of 246 studies (25.6%); this increased to 143 of 246 studies (58.1%) with addition of the decubitus view (P < .0001). CONCLUSION: The addition of decubitus views increased the number of diagnostically determinate studies and increased the ability to diagnose or exclude intussusception. The authors believe that a left-side-down decubitus view should be included in the initial evaluation of patients suspected of having intussusception, particularly when the supine view is diagnostically indeterminate.

Pulmonary tuberculous and tuberculous pericardial tamponade post lung transplant.

Pulmonary tuberculosis (TB) associated with tuberculous pericarditis after lung transplantation is a very rare entity. Here we report a unique case of cardiac tamponade due to tuberculous pericarditis, in a patient 4 months after single right lung transplantation, the patient underwent a subxyphoid pericardial window. The pericardial effusion analysis showed exudate effusion with high level of lymphocyte concentration. Both patient and donor didn't have history of TB or TB Exposure.

Ascending Aortic Graft Pseudoaneurysm With Sternal Erosion: A Presentation of Candidal Infection.

Fungal aortic graft infections are unusual and have been reported primarily in the abdominal aortic position. Ascending aortic graft infections secondary to Candida species have been reported rarely and invariably localized to the confines of the aortic graft. We present an interesting case of an ascending aortic graft infection with Candida albicans, with evidence of invasion of the sternum and overlying soft tissues.

A propensity matched analysis of outcomes and long term survival in stented versus stentless valves.

BACKGROUND: To compare the perioperative and long term survival after aortic valve replacement using stentless versus stented valves in a large cohort of patients grouped using propensity score matching. METHODS: From 1991 to 2012, 4,563 patients underwent aortic valve replacement with stentless and stented valves at our institution. Propensity score matching identified 444 pairs using 13 independent variables: incidence of operation, smoking status, renal failure, hypertension, diabetes, peripheral vascular disease, cerebrovascular disease, chronic lung disease, ejection fraction, gender, age, valve status, and use of coronary artery bypass graft. Data were collected from our Society of Thoracic Surgeons database and the Social Security Death Index. Groups were compared using univariate and Kaplan-Meier analysis. RESULTS: The two groups demonstrated no significant differences for the 13 matching variables and the majority of 30-day outcomes (p > 0.05). The stented valve group showed a higher incidence of postoperative bleeding (3.6% vs 1.1%, p = 0.015), but a lower incidence of stroke (0.9% vs. 2.9%, p = 0.028). One, five, and 10-year survival was 95.0, 80.7, and 52.8% for stented and 93.2, 80.5, and 51.3% for stentless valves. Overall survival did not differ significantly between the two groups (p = 0.641). CONCLUSIONS: Stentless and stented valves had identical 30-day outcomes except for a higher postoperative incidence of bleeding and a lower incidence of stroke in the stented group. There was no significant difference in long term survival between valve types. Both valves may be used for aortic valve replacement with low morbidity and excellent long term survival.

Outcomes in patients undergoing complex cardiac repairs with cross clamp times over 300 minutes.

BACKGROUND: Long cross clamp times have been associated with poor clinical outcomes, yet some patients require extremely long ischemic times to repair complex surgical problems. The purpose of this study was to examine short and mid-term survival and to identify risk factors for mortality and morbidity in patients with cross clamp times greater than or equal to 300 min. METHODS: Review of our institution's Society of Thoracic Surgeons database identified 202 patients who underwent surgical procedures necessitating aortic cross clamp times 300 min or greater between 2001 and 2012. Short-term (30-day) clinical outcomes were derived from this database and survival was assessed utilizing the Social Security Death Index. Univariate and multivariate analyses were used to determine the relationship between independent variables and mortality and postoperative outcomes. RESULTS: The average age of the patients was 69.5 ± 10.6 (mean ± standard deviation) years and the mean ejection fraction was 52 ± 12 %. 70.3 % of patients were male. Mean cross clamp time was 346 ± 45 min, and total bypass time was 421 ± 70 min. Thirty-day mortality was 12.4 %. The incidence of bleeding and stroke were 6.4 % and 4.0 % respectively. Prolonged ventilation occurred in 26.7 % of patients, and incidence of renal failure was 10.4 %. One, three, five, and seven year survival of the patients who survived the first 30 days post-surgery was 91.9 %, 83.2 %, 75.6 % and 65.7 % respectively. Proportional hazards analysis determined that the statistically significant hazard ratios for mid-term mortality for female gender, age, and prolonged postoperative ventilation were 2.11, 1.04 and 2.72, respectively (p < 0.05 for each). CONCLUSIONS: Cardiac procedures requiring extremely long ischemic times have significant early mortality and morbidity. However, mid-term survival in the patients who survive is good. Decision-making regarding operability in complex cases should allow for long ischemic times.