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.

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.

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.

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.

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.

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 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.

Exploring National Surgical Quality Improvement Program respiratory comorbidities: developing a predictive understanding of postoperative respiratory occurrences, Clavien 4 complications, and death.

BACKGROUND: For preoperative risk stratification, little is known about the implications of respiratory comorbidities in relation to postoperative complications in the diverse population of surgical patients. We hypothesized that patients with preoperative respiratory comorbidities would be at increased risk of postoperative respiratory occurrences and death. METHODS: Under the data use agreement and with the approval of the Henry Ford Health System Institutional Review Board (IRB #6830), we reviewed 5 y (2005-2009) of National Surgical Quality Improvement Program participant use files. Respiratory comorbidities were defined as current smoker, chronic obstructive pulmonary disease, dyspnea, and current pneumonia. Respiratory outcomes tracked in the National Surgical Quality Improvement Program included reintubation, postoperative pneumonia, and prolonged ventilation. We defined Clavien 4 and 5 outcomes to include postoperative septic shock, postoperative dialysis, pulmonary embolism, myocardial infarction, cardiac arrest, prolonged ventilatory requirements, need for reintubation, and death. RESULTS: Of 971,455 patients identified, 361,412 had respiratory comorbidities. As the number of respiratory comorbidities increased, we found a statistically significant increase in the occurrence of postoperative respiratory adverse events, including Clavien 4 and 5 complications. Multivariate regression analysis showed that respiratory comorbidities and age were independent predictors of mortality. All data reported here were significant at P < 0.001. CONCLUSIONS: This study showed a significant association between respiratory comorbidities and postoperative adverse events, including Clavien 4 complications and death. Further prospective studies are required to explore this association.

A modified frailty index to assess morbidity and mortality after lobectomy.

BACKGROUND: Frailty has yet to be explored as a risk factor for thoracic surgery. We hypothesized that our modified frailty index (mFI) may be a predictor of morbidity and mortality following lobectomy. MATERIALS: National Surgical Quality Improvement Program (NSQIP) participant use files were reviewed (2005-2010). Patients undergoing lobectomy were identified based on Current Procedural Terminology code 32480. We used an mFI with 11 variables, based on mapping the Canadian Study of Health and Aging Frailty Index to the NSQIP comorbidities. Data were analyzed using χ(2) test, independent sample t-test, Jonckheere-Terpstra test, and logistic regression. RESULTS: Of 1940 open lobectomy patients identified, morbidity and mortality uniformly increased as the mFI increased; 14.9% of patients (75/504) with mFI of 0 had at least one complication, compared with 32% of patients (91/284) with mFI of 0.27 (P < 0.001). An mFI of 0 was associated with a mortality rate of 1% (5/504), compared with 5.6% (16/284) for mFI of 0.27 (P < 0001). Failure to wean from the ventilator, reintubation, surgical site infections, pneumonia, and Clavien 4 and above complications occurred in 1.8% (9/504), 2.6% (13/504), 2.2% (11/504), 5.4% (27/504), and 4.2% (21/504), respectively, in patients with an mFI of 0, compared with 7.4% (21/284), 7% (22/284), 3.2% (9/284), 10.9% (31/284), and 14.4% (41/284), respectively, in patients with mFI of 0.27. CONCLUSIONS: This study demonstrates that the mFI may identify patients at higher risk for morbidity and mortality post-lobectomy. With the aging population, preoperative selection is important in minimizing morbidity and mortality and improving risk stratification for informed decision-making.

Simplified frailty index to predict adverse outcomes and mortality in vascular surgery patients.

BACKGROUND: Frailty has been established as an important predictor of health-care outcomes. We hypothesized that the use of a modified frailty index would be a predictor of mortality and adverse occurrences in vascular surgery patients. METHODS: Under the data use agreement of the American College of Surgeons, and with institutional review board (IRB) approval, the National Surgical Quality Improvement Program (NSQIP) Participant Utilization File was accessed for the years 2005-2008 for inpatient vascular surgery patients. Using the Canadian Study of Health and Aging Frailty Index (FI), 11 variables were matched to the NSQIP database. An increase in FI implies increased frailty. The outcomes assessed were mortality, wound infection, and any occurrence. We then compared the effect of FI, age, functional status, relative value units (RVU), American Society of Anesthesiology (ASA) score, and wound status on mortality. Statistical analysis was done using chi-square analysis and stepwise logistic regression. RESULTS: A total of 67,308 patients were identified in the database, 3913 wound occurrences, 6691 infections, 12,847 occurrences of all kinds, and 2800 deaths. As the FI increased, postoperative wound infection, all occurrences, and mortality increased (P < 0.001). Stepwise logistic regression using the FI with the NSQIP variables of age, work RVU, ASA class, wound classification, emergency status, and functional status showed FI to have the highest odds ratio (OR) for mortality (OR = 2.058, P < 0.001). CONCLUSIONS: A simplified FI can be obtained by easily identifiable patient characteristics, allowing for accurate prediction of postoperative morbidity and mortality in the vascular surgery population.

Is resternotomy a risk for continuous-flow left ventricular assist device outcomes?

BACKGROUND: The number of patients undergoing resternotomy continues to rise. Although catastrophic hemorrhage remains a dreaded complication, most published data suggest that sternal reentrance is safe, with negligible postoperative morbidity and mortality. A significant proportion of left ventricular assist device (LVAD) implantations are reoperative cardiac procedures. The aim of our study was to compare outcomes between first time sternotomy and resternotomy patients receiving continuous-flow LVADs, as a bridge to transplantation or destination therapy. METHODS AND MATERIALS: From March 2006 through February 2012, 100 patients underwent implantation of a HeartMate II or HeartWare LVAD at our institution. Patients were stratified into two groups, primary sternotomy and resternotomy. Variables were compared using two-sided t-tests, chi-square tests, Cox proportional hazards models, and log-rank tests to determine whether there was a difference between the two groups and if resternotomy was a significant independent predictor of outcome. RESULTS: We identified 29 patients (29%) who had resternotomy and 71 patients (71%) who had first time sternotomy. The resternotomy group was significantly older (56 years vs. 51 years, p = 0.05), was more likely to have ischemic cardiomyopathy (ICM) (69% vs. 30%, p < 0.001), chronic obstructive pulmonary disease (COPD) (31% vs. 14%, p = 0.05) and had longer cardiopulmonary bypass times (135 min vs. 100 min, p = 0.011). Survival rates at 30 days (93.1% vs. 95.8%, p = 0.564), 180 days (82.8% vs. 93%, p = 0.131), and 360 days (82.8% vs. 88.7%, p = 0.398) were similar for the resternotomy and primary sternotomy groups, respectively. Postoperative complications were also comparable, except for re-exploration for bleeding which was higher for the resternotomy group (17.2% vs. 4.2%, p = 0.029), although blood transfusion requirements were not significantly different (1.4 units vs. 1.2 units, p = 0.815). Left and right heart catheterization measurements and echocardiographic (ECHO) findings after 1 and 6 months of LVAD therapy were similar between the two groups. CONCLUSIONS: Survival at 30, 180, and 360 days after LVAD implantation is similar between the resternotomy and primary sternotomy group. No major differences in complications or hemodynamic measurements were observed. Although a limited observational study, our findings agree with previously published resternotomy outcomes.

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.

Clostridium difficile of the ileum following total abdominal colectomy, with or without proctectomy: who is at risk?

BACKGROUND: Clostridium difficile enteritis is considered a rare entity, although recent data suggest a significant increase in prevalence and incidence. There is paucity of data evaluating risk factors of C difficile enteritis following total colectomy. OBJECTIVE: The aim of this study was to determine the incidence and risk factors of C difficile enteritis for patients who had undergone total abdominal colectomy with or without proctectomy. DESIGN: This study involves a retrospective chart review of 310 patients. Univariate analysis was performed on potential risk factors (p ≤ 0.05) with the use of a logistic regression model, and a Fisher exact test was used for variables that had no occurrences of C difficile. These groups of variables were then examined in a multiple variate setting with stepwise logistic regression analysis. SETTINGS: This study was conducted at a tertiary referral center. PATIENTS: A data analysis was performed on patients who had undergone total abdominal colectomy with or without proctectomy who were tested for C difficile of the ileum. RESULTS: Twenty-two of 137 patients that were tested (16%) were positive for C difficile of the ileum. Univariate analysis of known risk factors for C difficile demonstrated that black race was a protective factor against C difficile (p = 0.016). The multivariate analysis demonstrated that emergency surgery (p = 0.035), race (p = 0.003), and increasing age by decade (p = 0.033) were risk factors for C difficile. LIMITATIONS: This study was limited by the small patient sample, and it was not a randomized trial. CONCLUSIONS: Black race is protective, and whites are 4 times more likely to acquire C difficile of the ileum after undergoing a total abdominal colectomy with or without proctectomy. The data also demonstrated that an increased age by a decade and emergency surgery are risk factors for C difficile enteritis, whereas the described risk factors of C difficile of the colon and type of colon surgery do not appear to influence the risk of C difficile of the ileum.

Preoperative risk stratification for thoracic surgery using the American College of Surgeons National Surgical Quality Improvement Program data set: functional status predicts morbidity and mortality.

BACKGROUND: Preoperative risk stratification for noncardiac thoracic surgery focuses on predicting postoperative lung capacity and cardiac risk. We hypothesized that preoperative functional status may be a predictor of morbidity and mortality after thoracic surgery. METHODS: The National Surgical Quality Improvement Program Participant Use Files from 2005 to 2009 were accessed, and current procedural terminology codes for procedures involving the lung and pleura were used to identify thoracic surgery patients. Patients were grouped by independent or dependent preoperative functional status. Risks of infectious and noninfectious complications were evaluated. Chi-square, Fisher exact, and multivariate analyses with stepwise logistic regression were used. This study was approved by the Institutional Review Board. RESULTS: Of 6,373 patients, 812 had a preoperative dependent functional status. Dependent patients had significantly higher rates of infection, other adverse events, and mortality. They were 9.3 times more likely (odds ratio [OR] 9.3) to have prolonged ventilation (P < 0.001) and 3.1 times more likely to be reintubated (P < 0.001). Postoperative pneumonia occurred in 10% (OR 2.7, P < 0.001). Postoperative mortality was 7.7 times higher (P < 0.001). Preoperative functional status, wound classification 3, and emergency procedures were independent predictors of both morbidity and mortality. Performing a thoracotomy was an independent risk factor for postoperative morbidity but not mortality (P < 0.001, OR 2 versus P = 0.415, OR 1.1). CONCLUSIONS: Thoracic surgery patients, classified as functionally dependent preoperatively are at high risk for major morbidity and mortality. Although a limited observational study, results show that functional status is an essential component of preoperative assessment for thoracic surgery patients.

Type A aortic dissection presenting with isolated paraplegia.

Acute type A thoracic aortic dissections most commonly present with sudden onset of severe chest and/or back pain. We summarize the case of a patient with an acute type A dissection who presented with acute, painless paraplegia caused by malperfusion of the artery of Adamkiewicz. Although an uncommon cause of acute paraplegia, type A dissections should be included in the differential diagnosis.

Incidental diagnosis of idiopathic gonadal vein thrombosis.

Gonadal vein thrombosis is a rare but well recognized entity which predominantly occurs in the post partum period. It is also associated with gynecological malignancies, cesarean deliveries, abortions, hypercoagulability and pelvic inflammatory disease. Prompt diagnosis and treatment is warranted to avoid serious complications. We report the rare case of idiopathic, unprovoked gonadal vein thrombosis.

Barrett's esophagus after resection of the gastroesophageal junction: effects of concomitant fundoplication.

BACKGROUND: Barrett's metaplasia has been known to occur after esophagectomy or gastrectomy in which the gastroesophageal junction with its associated lower esophageal sphincter has been resected. It is thought to be secondary to the refluxogenic nature of the operation. The present study was based on the hypothesis that patients who undergo a fundoplication with the resection would have a lower incidence of the development of postoperative Barrett's metaplasia. METHODS: All patients who underwent any type of esophagectomy or proximal gastrectomy in which the gastroesophageal junction was resected and an esophagogastrostomy performed were eligible for the study. Data gathered included age, gender, preoperative diagnosis, operation, postoperative pathology, occurrence and timing of postoperative upper endoscopy, and presence of Barrett's metaplasia on postoperative endoscopy. Statistical analysis was done with Fisher's exact test. RESULTS: Of the 179 patients who underwent resection, 151 had follow-up endoscopy documenting the presence or absence of Barrett's esophagus. Follow-up ranged from 6 months to 10 years. Of the 53 patients without fundoplications, 8 (18%) had Barrett's esophagus on follow-up upper endoscopy. Of the 98 patients with fundoplications, 5 (6%) had Barrett's esophagus (P = 0.04). CONCLUSIONS: The present study suggests that concomitant fundoplication with resection of the gastroesophageal junction may have some protective effect against the development of Barrett's esophagus. A randomized trial will be required to prove this assertion. Also, it is still unclear as to the consequences of the development of post-resection Barrett's esophagus.