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.

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.

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.

Factors defining occurrence of ischemic and hemorrhagic strokes during continuous flow left ventricular assist device support.

OBJECTIVE: LVAD-related strokes occur at a much higher rate compared to traditional open heart surgery. The pathophysiology of ischemic and hemorrhagic strokes after LVAD implantation is not well defined. The aim of this study was to better describe the etiopathogenesis of strokes during continuous flow LVAD support based on our institutional experience. METHODS: We performed a retrospective analysis of 200 patients, with and without stroke that underwent implantation of a continuous flow LVAD from 2011 to 2016. RESULTS: The incidences of stroke in our patient population were 13% (26/200), of which 50% (13/26) were ischemic and 50% hemorrhagic (13/26). Only 8% of strokes occurred within the first 48 h from LVAD implantation, all of which were ischemic. The median duration of support was 148 days for ischemic and 351 days (p = 0.012) for hemorrhagic strokes. The average mean arterial pressure measurements at the time of hospital discharge were 89 mmHg for patients who subsequently developed stroke and 72 mmHg (p = 0.03) for stroke-free patients. The average outpatient pressure measurements were 96 mmHg and 76 mmHg (p = 0.02) for the stroke and stroke-free patients, respectively. The mean velocity index showed the potential impairment of cerebral autoregulation. Multivariate analysis demonstrated that INR, COPD, aortic cross clamping, previous stroke, and device infections were statistically significant risk factors for stroke occurrence after LVAD implantation. CONCLUSIONS: In addition to LVAD-related thrombogenicity, the subsequent need for anticoagulation, and an acquired von Willebrand syndrome, several clinical factors, such as deviation from the anticoagulation regimen, hypertension, COPD, device infections, and aortic cross clamping, appear to have an influence on the extremely high rate of postoperative ischemic and hemorrhagic strokes.

Stroke after implantation of continuous flow left ventricular assist devices.

OBJECTIVE: Stroke remains a frequent and devastating complication after left ventricular assist device (LVAD) implantation, despite recent advances in device technology. The aim of this study was to analyze risk factors and outcomes of stroke following implantation of 200 continuous-flow LVADs at our institution. METHODS: We retrospectively analyzed patients who underwent LVAD implantation from 2011-2016. Data were available for a total of 200 patients. RESULTS: Post-LVAD stroke occurred in 13% of patients (26 of 200). Ischemic stroke occurred in 50% of patients (13 of 26), and hemorrhagic stroke in 50% (13 of 26). The median duration of LVAD support at the time of stroke was 257.4 days. Baseline characteristics did not differ significantly between the stroke and stroke-free cohorts. The mean international normalized ratio (INR) at the time of embolic stroke was 1.86 (range, 1.23-3.25) and 4.62 (range, 1.4-21.4) in patients with hemorrhagic stroke (P = .014). Mortality within 30 days of stroke was 31% (8 of 26). Mortality for hemorrhagic stroke was 63% (5 of 8) and 37% (3 of 8) for ischemic stroke ( P = .03). Among the 18 patients that survived stroke, 28% (5 of 18) received a heart transplant, 39% (7 of 18) are receiving ongoing LVAD support, and 33% (6 of 18) have died from unrelated causes. Multivariate analysis showed that INR level, aortic cross-clamping, a history of previous stroke, and postoperative infection were significant predictors for post-LVAD stroke. CONCLUSION: The occurrence of stroke significantly increases morbidity and mortality after LVAD implantation. Despite an adverse impact on survival and quality of life, several patients who suffered stroke still received a heart transplant. Furthermore, none of our patients had recurrence of a neurological event. Strict implementation of anticoagulation protocols is likely the mainstay of preventing this devastating complication.

Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplantation in the United States: A Multicenter Survey.

The clinical use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation (LTx) has greatly increased in recent years. However, clinical practices for ECMO as a bridge to LTx vary widely between LTx centers. To better define the current practice of ECMO as a bridge to LTx, we surveyed pre-LTx ECMO practices among all adult LTx programs in the United States. All US LTx centers were surveyed (n = 57) between January and December 2014. Responses were received from 33 of 57 centers (58%). Of 33 responding centers, six (18%) performed ≥50 LTxs per year (defined as high volume) and two (6%) performed <10 LTxs per year (low volume). Two-third of responding centers, 22/33 (67%), reported use of ECMO as a bridge to LTx. Of these 22 centers, 18 (82%) successfully used venovenous (VV) ECMO as a bridge to LTx using the dual-lumen Avalon cannula. Patient >65 years of age was judged an ECMO contraindication in 15/33 (45%) of responding centers, but 12/33 (36%) centers, including the six high-volume centers, had no official age cutoff for ECMO candidacy. There was no consensus on the maximum acceptable duration of pre-LTx ECMO therapy; although 18/33 (55%) of programs had no defined maximal duration of ECMO pre-LTx, 10/33 (30%) considered >10 days on ECMO support contraindicated. Our survey suggests that in the United States, ECMO is used frequently pre-LTx, particularly VV ECMO at high-volume centers. However, criteria for ECMO initiation, age eligibility, bedside care, and maximum duration of support varied significantly between survey respondents.

Risk assessment and outcomes of vasoplegia after cardiac surgery.

OBJECTIVE: The aim of this study was to analyze risk factors and outcomes of vasoplegia after cardiac surgery based on our experience with almost 2000 cardiac operations performed at our institution. METHODS: We retrospectively analyzed patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) between 2011 and 2013. Data were available for a total of 1992 patients. We defined vasoplegia as hypotension with persistently low systemic vascular resistance (<800 dyn/s/cm) and preserved Cardiac Index (>2.5). RESULTS: The rate of vasoplegia in our cohort was 20.3% (n = 405). The incidences of mild, moderate, and severe vasoplegia were 13.2, 5.7, and 1.5%, respectively. Factors that increased risk of vasoplegia included valve operations, heart transplants, dialysis-dependent renal failure, age >65, diuretic therapy, and recent myocardial infarction. B blocker therapy was protective against vasoplegia. CONCLUSION: Vasoplegic syndrome is still a frequently occurring adverse event following cardiac surgery. In high risk patients for vasoplegia, it may be sensible to proceed with preoperative volume loading (instead of diuresis), initiation of low dose vasopressin therapy if needed, and attempting to up titrate beta-blocker therapy.

Heart transplant outcomes in recipients of Centers for Disease Control (CDC) high risk donors.

BACKGROUND: A lack of donor hearts remains a major limitation of heart transplantation. Hearts from Centers for Disease Control (CDC) high-risk donors can be utilized with specific recipient consent. However, outcomes of heart transplantation with CDC high-risk donors are not well known. We sought to define outcomes, including posttransplant hepatitis and human immunodeficiency virus (HIV) status, in recipients of CDC high-risk donor hearts at our institution. METHODS: All heart transplant recipients from August 2010 to December 2014 (n = 74) were reviewed. Comparison of 1) CDC high-risk donor (HRD) versus 2) standard-risk donor (SRD) groups were performed using chi-squared tests for nominal data and Wilcoxon two-sample tests for continuous variables. Survival was estimated with Kaplan-Meier curves. RESULTS: Of 74 heart transplant recipients reviewed, 66 (89%) received a SRD heart and eight (11%) received a CDC HRD heart. We found no significant differences in recipient age, sex, waiting list 1A status, pretransplant left ventricular assist device (LVAD) support, cytomegalovirus (CMV) status, and graft ischemia times (p = NS) between the HRD and SRD groups. All of the eight HRD were seronegative at the time of transplant. Postoperatively, there was no significant difference in rejection rates at six and 12 months posttransplant. Importantly, no HRD recipients acquired hepatitis or HIV. Survival in HRD versus SRD recipients was not significantly different by Kaplan-Meier analysis (log rank p = 0.644) at five years posttransplant. CONCLUSION: Heart transplants that were seronegative at the time of transplant had similar posttransplant graft function, rejection rates, and five-year posttransplant survival versus recipients of SRD hearts. At our institution, no cases of hepatitis or HIV occurred in HRD recipients in early follow-up.

Open Seldinger-Guided Femoral Artery Cannulation Technique for Thoracic Aortic Surgery.

BACKGROUND: Debate regarding the optimal cannulation site for aortic surgery continues. We report our recent experience with a simple and rapid open Seldinger-guided technique for femoral cannulation. Aside from speed and simplicity (no need for arterial incision or suture closure), this technique has the added benefit that the distal limb continues to be perfused, as no arterial snare is required. METHODS: We recently began routinely utilizing an open Seldinger-guided technique for femoral artery cannulation. The artery is exposed surgically but cannulated by guidewire inside a pursestring without arterial incision. The pursestring is simply tied when decannulation is performed. We report our experience with the routine application of this technique from August 2011 to April 2015. RESULTS: We reviewed the outcome of 337 consecutive peripheral arterial cannulations performed for thoracic aortic surgery (303 femoral, 34 axillary) using the open Seldinger technique. Within the femoral cannulation group, the hospital survival rate was 97% (295 of 303). The survival rate for elective operations was 98% (277 of 283), and 90% (18 of 20) for emergent/urgent. Seldinger-guided femoral cannulation was performed for replacement of the ascending/aortic arch in 88% (266 of 303), the descending thoracic aorta in 7% (22 of 303), and the thoracoabdominal aorta in 5% (15 of 303). There were no instances of intraoperative malperfusion phenomena, arterial dissection, or vascular injury or rupture. No patients had postoperative acute limb ischemia. Local wound complications were observed in 1% of patients (3 of 303). The stroke rate was 1.6% (5 of 303). The same open Seldinger technique was also used without complication in the axillary cannulation group. CONCLUSIONS: An open Seldinger-guided femoral (or axillary) cannulation technique is quick and easy to perform, with minimal vascular or other complications and extremely low risk of stroke. This technique is recommended for its speed, simplicity, and effectiveness, and for its preservation of distal arterial flow (which is occluded with the traditional arterial incision/arterial snare technique).

Short and long term outcomes of 200 patients supported by continuous-flow left ventricular assist devices.

AIM: To study the institutional experience over 8 years with 200 continuous-flow (CF) - left ventricular assist devices (LVAD). METHODS: We evaluated our institution's LVAD database and analyzed all patients who received a CF LVAD as a bridge to transplant (BTT) or destination therapy from March 2006 until June 2014. We identified 200 patients, of which 179 were implanted with a HeartMate II device (Thoratec Corp., Pleasanton, CA) and 21 received a Heartware HVAD (HeartWare Inc., Framingham, MA). RESULTS: The mean age of our LVAD recipients was 59.3 years (range 17-81), 76% (152/200) were males, and 49% were implanted for the indication of BTT. The survival rate for our LVAD patients at 30 d, 6 mo, 12 mo, 2 years, 3 years, and 4 years was 94%, 86%, 78%, 71%, 62% and 45% respectively. The mean duration of LVAD support was 581 d (range 2-2595 d). Gastrointestinal bleeding (was the most common adverse event (43/200, 21%), followed by right ventricular failure (38/200, 19%), stroke (31/200, 15%), re exploration for bleeding (31/200, 15%), ventilator dependent respiratory failure (19/200, 9%) and pneumonia (15/200, 7%). Our driveline infection rate was 7%. Pump thrombosis occurred in 6% of patients. Device exchanged was needed in 6% of patients. On multivariate analysis, preoperative liver dysfunction, ventilator dependent respiratory failure, tracheostomy and right ventricular failure requiring right ventricular assist device support were significant predictors of post LVAD survival. CONCLUSION: Short and long term survival for patients on LVAD support are excellent, although outcomes still remain inferior compared to heart transplantation. The incidence of driveline infections, pump thrombosis and pump exchange have declined significantly in recent years.

Robot-Assisted Minimally Invasive Ivor Lewis Esophagectomy With Real-Time Perfusion Assessment.

BACKGROUND: Surgical resection is viewed as the most effective way to ensure both locoregional control and long-term survival in esophageal cancer. Although minimally invasive esophagectomy has been widely accepted as an alternative to open surgery, the role of robotic assistance has yet to be elucidated. We report our institutional experience with robotic-assisted Ivor Lewis esophagectomy using real-time perfusion assessment and demonstrate this as a safe and technically feasible alternative to traditional open Ivor Lewis esophagectomy. METHODS: A retrospective chart review of all patients undergoing robotic-assisted Ivor Lewis esophagectomy at a single institution from 2011 to 2014 was performed. Operative and postoperative outcomes were recorded. RESULTS: Fifty-four patients underwent robotic-assisted Ivor Lewis esophagectomy during the study period. Indication for surgery was cancer in 49 patients, 38 of whom underwent neoadjuvant chemoradiation therapy. The average operative time was 6 hours 2 minutes, and the average blood loss was 74 mL. There was 1 postoperative mortality (1.9%). Three (5.5%) patients experienced an anastomotic leak. The average number of lymph nodes harvested in cancer patients was 16.2 (range, 3 to 35). The average length of stay was 12.9 days. CONCLUSIONS: Our study demonstrates that robotic-assisted Ivor Lewis esophagectomy using real-time perfusion assessment is a safe and technically feasible alternative to traditional open Ivor Lewis esophagectomy. It allows for R0 resection with adequate lymph node harvesting and a short hospital stay.

Outcomes of patients with right ventricular failure on milrinone after left ventricular assist device implantation.

Previous studies have grouped together both patients requiring right ventricular assist devices (RVADs) with patients requiring prolonged milrinone therapy after left ventricular assist device (LVAD) implantation. We retrospectively identified 149 patients receiving LVADs and 18 (12.1%) of which developed right ventricular (RV) failure. We then separated these patients into those requiring RVADs versus prolonged milrinone therapy. This included 10 patients who were treated with prolonged milrinone and eight patients who underwent RVAD placement. Overall, the RV failure group had worse survival compared with the non-RV failure cohort (p = 0.038). However, this was only for the subgroup of patients who required RVADs, who had a 1, 6, 12, and 24 month survival of 62.5%, 37.5%, 37.5%, and 37.5%, respectively, versus 96.8%, 92.1%, 86.7%, and 84.4% for patients without RV failure (p < 0.001). Patients treated with prolonged milrinone therapy for RV failure had similar survivals compared with patients without RV failure. In the RV failure group, age, preoperative renal failure, and previous cardiac surgery were predictors of the need for prolonged postoperative milrinone. As LVADs become a more widely used therapy for patients with refractory, end-stage heart failure, it will be important to reduce the incidence of RV failure, as it yields significant morbidity and increases cost.

Cryptococcal aortitis presenting as a symptomatic abdominal aortic aneurysm.

We report a case of cryptococcal aortitis in a 59-year-old man presenting as a symptomatic suprarenal abdominal aortic aneurysm (AAA). The patient underwent repair of his aneurysm using a rifampin-soaked graft with omental wrapping. Intraoperative Gram stains showed yeast organisms, the cultures eventually grew Cryptococcus neoformans with results available 43 days postoperatively. He was started on antifungal therapy intraoperatively and will be on lifelong antifungal treatment. Our case is the first report of cryptoccocal aortitis presenting as a symptomatic AAA; the diagnosis of a true mycotic aneurysm was made intraoperatively.

Lessons learned from 150 continuous-flow left ventricular assist devices: a single institutional 7 year experience.

Continuous-flow (CF) left ventricular assist devices (LVADs) have become the standard of care for patients with advanced heart failure refractory to optimal medical therapy. The goal of this study was to review our 7 year single institutional experience with CF LVADs. Mean age was 50.4 + 12.5 (17-69) years for bridge-to-transplantation (BTT) patients and 57.6 + 10.4 (31-81) years for destination therapy (DT) patients (p < 0.001). Overall, 38 patients (26%) were female and 58 (41%) were African American. Etiology of heart failure was ischemic in 54 patients (37%) and nonischemic in 93 patients (63%). Overall survival at 30 days, 6 months, 12 months, and 2 years was 93%, 89%, 84%, and 81%, respectively. Gastrointestinal bleeding (GIB) was the most common complication (24%), followed by stroke (18%), right ventricular (RV) failure (18%), ventilator-dependent respiratory failure (10%), reoperation for bleeding (10%), and driveline infection (9%). These data demonstrate excellent survival with low mortality for both BTT and DT patients on long-term LVAD support. However, for LVAD therapy to become the gold standard for long-term treatment of end-stage heart failure and a plausible alternative to heart transplantation, we need to continue to improve the incidence of frequent postoperative complications, such as RV failure, driveline infections, strokes, and GIB.

Factors determining post-operative readmissions after left ventricular assist device implantation.

BACKGROUND: In the current era of extensive healthcare reform, there has been a heightened focus on the frequency and cause for readmissions within 30 days of discharge given that readmissions are not reimbursed by most providers. The aim of our study was to determine the frequency, etiology and patterns of 30-day readmissions among recipients of continuous-flow left ventricular assist devices (LVADs) at our institution as well to determine whether there were any significant predictors of readmission. METHODS: From March 2006 through June 2013, 150 patients underwent implantation of a continuous-flow LVAD at our institution. Patients were stratified into two groups based on their 30-day readmission status. A total of 12 patients died before discharge and were excluded from our analysis. Causes for 30-day readmissions and duration of hospital stay for the readmissions were recorded. Numerous pre-operative variables and post-operative complications were compared using 2-sided t-tests and chi-square tests between patients who were and were not readmitted within 30 days of their discharge after their LVAD implant. RESULTS: The 30-day readmission rate was 26.1% (36 of 138), with approximately 70% of post-operative readmissions occurring within 10 days of the patient's initial hospital discharge. Recurrent heart failure (12 of 36, 33.3%) and gastrointestinal bleeding (8 of 36, 22.2%) were the most common causes for 30-day readmission. The median length of stay (LOS) for readmission was 11.7 days. Thirty-day readmission did not affect short- or long-term survival. On univariate analysis, post-operative gastrointestinal bleeding (GIB) was a significant risk factor for 30-day readmissions (HR 1.4, 95% CI 0.19 to 0.99, p = 0.05), and overall length of stay was a significant factor in reducing 30-day readmission rates (HR 0.91, 95% CI 0.85 to 0.99, p = 0.02). CONCLUSIONS: Our experience indicates that 30-day readmission rates after LVAD implantation remain relatively high, with most occurring within 10 days of discharge. Recurrent heart failure and GIB were the most common causes of post-operative rehospitalization. In addition, GIB during the index hospitalization was a significant predictor of 30-day readmission.

Method of treating patients with acute type A aortic dissection and lower extremity malperfusion.

The management of an acute type A aortic dissection in the setting of peripheral vascular malperfusion is not well defined. Several institutions proceed with initial percutaneous intervention to restore end organ perfusion, followed by delayed operative repair of the type A dissection. This strategy is associated with high mortality rates from aortic rupture, myocardial infarction, and stroke. We describe a technique, where acute limb ischemia is concomitantly managed with the replacement of the ascending aorta/hemiarch or aortic arch. In addition to axillary artery cannulation, the ischemic lower extremity is perfused through a polytetrafluoroethylene (PTFE) graft, which is connected to the cardiopulmonary bypass (CPB) circuit.

Does elective or emergent operative status influence outcomes in patients undergoing implantation of left ventricular assist devices?

BACKGROUND: Acuity models to predict survival after left ventricular assist device (LVAD) implantation do not include operative status as one of the calculated variables. The effect of elective versus emergent LVAD implantation on outcomes has not been examined. METHODS: Patients were stratified into 2 groups based on operative status (elective versus emergent). Variables were compared to determine whether there were differences in outcomes between elective versus emergent LVAD recipients RESULTS: Of the 130 patients, 59 underwent an elective procedure, whereas 71 had their LVAD implanted as an urgent/emergent operation. Patients in the urgent/emergent cohort had significantly worse preoperative hepatic and renal function and higher central venous pressures. Survival rates at 30 days, 6 months, 1 year, and 2 years were analogous for both cohorts. Patients in the emergent cohort had a higher incidence of postoperative right ventricular failure, with the requirement for short-term right ventricular support in 9.9% versus 1.7% (P = 0.054). The incidence of other LVAD-related complications, were similar in both groups. Emergency status did not predict postoperative mortality in univariate analysis. CONCLUSIONS: Although patients who underwent emergent LVAD implantations had worse preoperative renal and liver function and a higher incidence of postoperative right ventricular failure, they exhibited similar midterm survival and a similar incidence of other postoperative complications.