Surgical Technique And Clinical Implications Of Transcatheter Aortic Valve Bioprosthesis Explantation.

There has been a worldwide rapid adoption of transcatheter aortic valve replacement (TAVR) as an alternative to surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis. Currently, more TAVR explants with SAVRs are performed than TAVR-in TAV. TAVR explantation is a technically hazardous procedure mainly due to significant aortic neo-endothelialization which incorporates the TAVR valve. Surgical techniques for TAVR explantation are not well established and surgeon experience at present is limited. In this manuscript, we describe our technique for surgical explantation of transcatheter aortic bioprosthesis. Familiarity with the procedure and its clinical implications is essential for all cardiac surgeons.

Simulation Training for Emergency Sternotomy in the Cardiovascular Intensive Care Unit.

BACKGROUND: Emergency resternotomy in the intensive care unit for a patient who has undergone cardiac surgery can be daunting for surgeons and critical care staff. Clinicians involved are often unfamiliar with the surgical instruments and techniques needed. LOCAL PROBLEM: After an emergency intensive care unit resternotomy resulted in suboptimal performance and outcome, protocols for emergency resternotomy were established and improved. METHODS: Education and simulation training were used to improve staff comfort and familiarity with the needed techniques and supplies. The training intervention included simulations to provide hands-on experience, improve staff familiarity with resternotomy trays, and streamline emergency sternotomy protocols. Preintervention and postintervention surveys were used to assess participants' familiarity with the implemented plans and algorithms. RESULTS: All 44 participants (100%) completed the preintervention survey, and 41 of 44 participants (93%) returned the postintervention survey. After the intervention, 95% of respondents agreed that they were prepared to be members of the team for an emergency intensive care unit sternotomy, compared with 52% of respondents before the intervention. After the intervention, 95% of respondents strongly agreed or agreed that they could identify patients who might need emergency sternotomy, compared with 50% before the intervention. The results also showed improvement in staff members' understanding of team roles, activation and use of the emergency sternotomy protocol, and differences between guidelines for resuscitating patients who experience cardiac arrest after cardiac surgery and the post-cardiac arrest Advanced Cardiovascular Life Support protocol. CONCLUSION: Results of this quality improvement project suggest that simulation training improves staff comfort with and understanding of emergency resternotomy.

Coronary artery bypass surgery in a patient with Bartter's syndrome - postoperative critical care management: a case report.

Bartter syndrome is a rare, renal tubulopathy caused by defective salt reabsorption in the thick ascending limb of the loop of Henle which results in salt wasting, hypokalemia, and metabolic disturbances. The electrolyte disturbances associated with this condition can be difficult to manage in the postoperative setting, especially in patients undergoing cardiac surgery. We report a case of a 62-year-old male with a history of diabetes, hypertension, coronary artery disease, and Bartter syndrome who underwent coronary artery bypass grafting and who developed severe lactic acidemia and severe electrolyte abnormalities postoperatively. Treatment consisted of aggressive resuscitation with crystalloid and intravenous (IV) electrolyte replacement.

Left ventricular assist devices: yesterday, today, and tomorrow.

The shortcomings of expense, power requirements, infection, durability, size, and blood trauma of current durable LVADs have been recognized for many years. The LVADs of tomorrow aspire to be fully implantable, durable, mitigate infectious risk, mimic the pulsatile nature of the native cardiac cycle, as well as minimize bleeding and thrombosis. Power draw, battery cycle lifespan and trans-cutaneous energy transmission remain barriers to completely implantable systems. Potential solutions include decreases in pump electrical draw, improving battery lifecycle technology and better trans-cutaneous energy transmission, potentially from Free-range Resonant Electrical Energy Delivery. In this review, we briefly discuss the history of LVADs and summarize the LVAD devices in the development pipeline seeking to address these issues.

Left Atrial-Veno Arterial Extracorporeal Membrane Oxygenation as a Bridge to Surgery for Endocarditis-Related Acute Severe Aortic Regurgitation.

Mechanical circulatory support for cardiogenic shock complicated by acute severe aortic regurgitation poses a unique challenge for traditional veno arterial extracorporeal membrane oxygenation (ECMO) because of rapidly rising left ventricular pressures accentuated by the increased afterload from retrograde flow in femoral cannulation. This process necessitates rapid left ventricular unloading while also allowing for adequate native left ventricular function. Herein, we describe a case of cardiogenic and septic shock secondary to methicillin-resistant Staphylococcus aureus complicated by acute severe aortic regurgitation temporized by left atrial-veno arterial (LA-VA) ECMO via the Livanova TandemHeart system. Left ventricular unloading created a window of hemodynamic stability allowing for optimization of multiorgan failure and infectious source control before surgical aortic valve replacement.

Ruptured Penetrating Atherosclerotic Ulcer Repaired With an Amplatzer Atrial Septal Occluder.

Ascending aortic pseudoaneurysms are an infrequent but life-threatening complication of cardiac and aortic surgery. Although rare, these pseudoaneurysms can form as a complication of penetrating atherosclerotic ulcers. We report a case of a ruptured penetrating atherosclerotic ulcer repaired percutaneously with an Amplatzer Atrial Septal Occluder (Abbott, Plymouth, MN, USA).

Fundamentals of weaning veno-arterial and veno-venous extracorporeal membrane oxygenation.

Recent advances in veno-arterial (VA) and veno-venous (VV) extracorporeal membrane oxygenation (ECMO) technology and management have enabled us to support patients with cardiac and/or pulmonary failure, who may have previously been considered untreatable. VA ECMO and VV ECMO are by definition transient therapies and serve as a bridge to recovery, bridge to decision, bridge to transplant, or bridge to no recovery. Weaning ECMO should be considered for all patients once native cardiac and pulmonary function show signs of recovery. Currently, there are no universally accepted protocols for weaning VA and VV ECMO, and consequently, each individual center follows their own weaning protocols. The aim of this review article is to describe different approaches to safely wean from VA and VV ECMO.

Ventilatory Failure And Pulmonary Embolism In Covid-19 Requiring Enhanced Venous Drainage For Extracorporeal Membrane Oxygenation.

COVID-19 infection manifests as a spectrum of respiratory and vascular complications, including acute respiratory distress syndrome (ARDS) and pulmonary embolism. Herein, we describe a case of a healthy young male who presented with ARDS refractory to mechanical ventilation and concomitant bilateral pulmonary emboli managed with extracorporeal membrane oxygenation (ECMO) and embolectomy. The embolectomy and initial veno-venous ECMO configuration failed to correct the patient's hypoxemia despite maximal flows. This was thought to be due to a high-output state secondary to vasodilatory shock preventing adequate drainage from the existing single drainage ECMO cannulation, following which a second venous cannula was placed to form a unique veno-veno-venous ECMO circuit that resolved the persistent hypoxemia. The case underscores the importance of identifying embolic events and vasodilatory shock in COVID-19 patients, both of which need to be addressed simultaneously to avoid worsening right ventricular failure (via both mechanical and hypoxia-driven pathways) and the resulting veno-arterial ECMO along with its associated complications.

Valvectomy Versus Replacement for the Surgical Treatment of Tricuspid Endocarditis.

BACKGROUND: Optimal surgical treatment of infective tricuspid endocarditis is debatable, especially in the setting of inherent social and pathologic concerns. This study compared tricuspid valve repair, replacement, and excision for the treatment of infective endocarditis METHODS: A single-center cardiac surgery database was queried to identify patients aged older than 18 years who underwent tricuspid valve operations for infective endocarditis between 2012 and 2016. Patients were divided into three groups by the type of tricuspid valve operation: valvectomy, repair, or replacement. Patients were evaluated to identify differences between preoperative factors and outcomes, including death, length of stay, and complications. RESULTS: During the study period, 63 patients underwent surgical treatment of infective tricuspid valve endocarditis. Demographic and baseline characteristics were comparable across all groups, except that the valve repair group was older compared with valvectomy and replacement (46 vs 29 and 31 years, respectively; p = 0.007), with more hypertension, elevated creatinine, and a lower incidence of diffuse, bilateral pulmonary emboli. Staphylococcus species were the most common organisms. The incidence of death, bleeding requiring reoperation, major stroke, prolonged ventilator time, intensive care unit stay, and overall hospital length of stay were similar in all groups. Of patients undergoing initial valvectomy, 36% were available for follow-up at 1 year, highlighting the challenges associated with the intravenous drug abuse cohort. Patients who underwent tricuspid valvectomy in the group available for follow-up had significantly lower unplanned readmission rates at 1 year. CONCLUSIONS: Tricuspid valve endocarditis patients who undergo tricuspid valve excision, repair, and replacement have similar 30-day operative mortality, as defined by The Society of Thoracic Surgeons. Excision patients have significantly lower unplanned readmission rates at 1 year. Tricuspid valvectomy is an acceptable initial treatment in this high-risk group as part of a surgical strategy to identify patients who are candidates for eventual valve replacement. Further study of long-term outcomes and survival is warranted.

Surgical Treatment of Benign Superior Vena Cava Syndrome.

The obstruction of blood flow through the superior vena cava (SVC) into the right atrium may present as a severe clinical syndrome. One of the benign causes of SVC obstruction is the long-term use of indwelling catheters and wires, increasing the chances of SVC thrombosis. The treatment of the benign SVC syndrome is focused on achieving long-term durability and patency of the superior venocaval system and normal life expectancy. We report the successful surgical management of a patient with severe symptomatic SVC syndrome and emphasize technical details that might be of value in treating this challenging pathologic condition.

Pseudoangiomatous Stromal Hyperplasia on Core Needle Biopsy Does Not Require Surgical Excision.

Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon, benign localized fibrotic lesion. Historically, PASH has been difficult to differentiate from angiosarcoma. This difficulty has led to recommendations of surgical excision. We sought to identify the incidence of upgraded pathology to atypia or malignancy on surgical excisional biopsy after identification of PASH on core needle biopsy (CNB). A 5-year retrospective review at a single institution was conducted including all cases of PASH confirmed on CNB. The data set was divided into patients who underwent excisional biopsy and those followed only by imaging. Primary end points included the incidence of subsequent malignancy or high-risk pathology on histologic analysis or the presentation of suspicious imaging. Thirty-seven patients were reviewed, 19 (51.4%) underwent surgical excision and 18 (48.6%) were followed with imaging alone. A palpable mass was noted in 36.8 per cent of patients in the excisional group versus 5.6 per cent in the imaging group (P = 0.02). The median follow-up for the excisional and imaging groups were 43 and 35 months, respectively (P = 0.85). The 95 per cent confidence interval for the presence of malignancy was 0 to 9.4 per cent. Although further characterization of PASH is needed, our data support using CNB with follow-up imaging as a safe alternative to excisional biopsy in the absence of symptoms or other clinical factors. However, further research in this area is needed.

A matrix-assisted laser desorption/ionization compatible reagent for tagging tryptophan residues.

Chemical tagging of amino acids is an important tool in proteomics analysis, and has been used to introduce isotope labels and mass defect labels into proteolytic peptides by derivatization of cysteine or lysine residues. Here, we present a new reagent with chemical specificity for tryptophan residues. Previously, 2-nitrobenzenesulfenyl chloride has been used as a highly specific reagent for labeling tryptophan residues. We show that this tag undergoes UV dissociation during matrix assisted laser desorption/ionization (MALDI). The multiplicity of photofragments increases the difficulty of characterizing the derivatization products. To overcome this problem, we have synthesized a new reagent, 2-(trifluoromethyl)benzenesulfenyl chloride, which is shown to react quantitatively with tryptophan in peptides and proteins. Most significantly, it exhibits high photostability in MALDI-Fourier transform mass spectrometry analyses.