Clinical Experience of HeartMate II to HeartWare Left Ventricular Assist Device Exchange: A Multicenter Experience.

BACKGROUND: Despite improvements in pump design and durability, left ventricular assist device patients still suffer from life-threatening complications such as pump thrombosis (PT) and infection, often necessitating device exchange. Surgical exchange from HeartMate II (HM2; Abbott, Pleasanton, CA) to another HM2 is safe and associated with low mortality, but recurrent device thrombosis rates are high. Switching from axial-flow to centrifugal-flow pump, such as the HeartWare ventricular assist device (HVAD; Medtronic, Framingham, MA) may offer certain advantages due to it being a smaller, newer generation device, although there are limited data to support this strategy. Herein, we aimed to assess the surgical approach and feasibility, safety, and outcomes of surgical exchange from HM2 to HVAD. METHODS: We evaluated HM2 patients who underwent device exchange to HVAD due to PT or infection at 4 large-volume left ventricular assist device implant centers. RESULTS: Twenty-four patients underwent HM2 to HVAD exchange due to PT (92%) and refractory infection (8%). Patients were male (75%), white (88%), with ischemic cardiomyopathy (54%), Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) scale level 1-3 (90%), and destination therapy (62%). The majority underwent redo-sternotomy (79%) and the remainder underwent minimally invasive thoracotomy with subcostal approach. The existing HM2 outflow graft was maintained in 79% of cases. Recurrent PT was noted in 9% of patients. Mortality was 8% at 30 days and 33% at 1 year. CONCLUSIONS: The surgical exchange from a HM2 to HVAD is safe and feasible, despite the differences in device specifications and surgical adaptation required. Newer-generation pumps are increasingly considered for exchange in the setting of HM2 device complication, and increasing experience with modified surgical approaches may be valuable in the current era.

Organ-mounted robot localization via function approximation.

BACKGROUND: Organ-mounted robots adhere to the surface of a mobile organ as a platform for minimally invasive interventions, providing passive compensation of physiological motion. This approach is beneficial during surgery on the beating heart. Accurate localization in such applications requires accounting for the heartbeat and respiratory motion. Previous work has described methods for modeling quasi-periodic motion of a point and registering to a static preoperative map. The existing techniques, while accurate, require several respiratory cycles to converge. METHODS: This paper presents a general localization technique for this application, involving function approximation using radial basis function (RBF) interpolation. RESULTS: In an experiment in the porcine model in vivo, the technique yields mean localization accuracy of 1.25 mm with a 95% confidence interval of 0.22 mm. CONCLUSIONS: The RBF approximation provides accurate estimates of robot location instantaneously.

Combined carotid endarterectomy and transcatheter aortic valve replacement: Technique and outcomes.

BACKGROUND: Stroke and transient ischemic attack after transcatheter aortic valve replacement results in significantly higher morbidity and mortality. Severe carotid artery disease may be a contributing factor to this increased risk. We report our technique and outcomes of combined carotid endarterectomy (CEA) with transcatheter aortic valve replacement (TAVR). METHODS: From March 2013 to November 2017 a total of 753 TAVRs were performed at our institution for symptomatic severe aortic stenosis. Of this group, 16 patients underwent concomitant TAVR and CEA. A retrospective review was performed to assess risk, outcomes, and short-term survival. RESULTS: Sixteen patients underwent concomitant CEA/TAVR procedures for severe carotid and severe aortic stenosis. The mean Society of Thoracic Surgeons (STS) Risk Score was 7.0 ± 4.7. All patients had severe carotid artery stenosis and aortic stenosis. Nine patients had a transfemoral TAVR approach and eight patients had a transapical TAVR approach. The mean length of stay was 6.4 ± 3.7 days. At 30 days there were no cerebrovascular events and no mortalities. CONCLUSIONS: The use of concomitant CEA and TAVR in patients with severe aortic stenosis and severe carotid stenosis can be done safely without increased risk of complications. This approach may reduce the risk of stroke associated with TAVR in appropriately selected patients.

Beating-heart registration for organ-mounted robots.

BACKGROUND: Organ-mounted robots address the problem of beating-heart surgery by adhering to the heart, passively providing a platform that approaches zero relative motion. Because of the quasi-periodic deformation of the heart due to heartbeat and respiration, registration must address not only spatial registration but also temporal registration. METHODS: Motion data were collected in the porcine model in vivo (N = 6). Fourier series models of heart motion were developed. By comparing registrations generated using an iterative closest-point approach at different phases of respiration, the phase corresponding to minimum registration distance is identified. RESULTS: The spatiotemporal registration technique presented here reduces registration error by an average of 4.2 mm over the 6 trials, in comparison with a more simplistic static registration that merely averages out the physiological motion. CONCLUSIONS: An empirical metric for spatiotemporal registration of organ-mounted robots is defined and demonstrated using data from animal models in vivo.

A parallel wire robot for epicardial interventions.

This paper describes the design and preliminary testing of a planar parallel wire robot that adheres to the surface of the beating heart and provides a stable platform for minimally invasive epicardial therapies. The device is deployed through a small subxiphoid skin incision and attaches to the heart using suction. This methodology obviates mechanical stabilization and lung deflation, which are typically required during minimally invasive beating-heart surgery. The prototype design involves three vacuum chambers connected by two flexible arms. The chambers adhere to the epicardium, forming the vertices of a triangular base structure. Three cables connect a movable end-effector head to the three bases; the cables then pass out of the body to external actuators. The surgical tool moves within the triangular workspace to perform injections, ablation, or other tasks on the beating heart. Tests in vitro and in vivo were conducted to demonstrate the capabilities of the system. Tests in vivo successfully demonstrated the ability to deploy through a subxiphoid incision, adhere to the surface of the beating heart, move the surgical tool head within the robot's workspace, and perform injections into the myocardium.

Insertion of an Abiomed Impella® left ventricular assist device following bioprosthetic aortic valve placement.

BACKGROUND: Post-cardiotomy cardiogenic shock is an infrequent devastating complication with few options for support. MATERIALS AND METHODS: We present a case highlighting use of the Impella 5.0 (ABIOMED; Danvers, MA) for postcardiotomy cardiogenic shock after coronary artery bypass and bioprosthetic aortic valve replacement. RESULTS: Support was maintained for 7 days before being successfully weaned with myocardial recovery and no damage to the bioprosthetic aortic valve. CONCLUSIONS: This is the first published report of successful use of an Impella 5.0 (ABIOMED; Danvers, MA) for post-cardiotomy cardiogenic shock through a new implanted bioprosthetic aortic valve.

Use of extracorporeal membrane oxygenation support during an emergent decompression of a thoracic epidural abscess.

STUDY DESIGN: Case report. OBJECTIVE: To present the first reported case of using extracorporeal membrane oxygenation (ECMO) support in an emergent decompression and evacuation of a thoracic epidural abscess. SUMMARY OF BACKGROUND DATA: Thoracic epidural abscesses with neurological deficits require surgical evaluation and intervention in most cases. We report a case of a 35-year-old patient with an acute onset of paraplegia diagnosed with a thoracic epidural abscess. The patient was emergently taken to the operating room and was unable to tolerate prone positioning secondary to cardiopulmonary collapse. ECMO was initiated for cardiopulmonary support to complete the case. METHODS: Retrospective chart review of patient case. RESULTS: The patient was stabilized with ECMO support and tolerated a T4-T8 laminectomy and decompression. The source of the patients abscess was hematogenous and at 6 months of clinical follow-up, the patient has no motor or sensory function of his bilateral lower extremities. CONCLUSION: The use of ECMO support in adult spinal surgery has not been previously reported in the literature. Therefore we describe the first reported use of ECMO to maintain cardiopulmonary support in a patient unable to tolerate prone positioning during spine surgery. ECMO support can be a viable option in adult patients who need emergent spinal surgery but are unable to tolerate prone positioning secondary to cardiopulmonary complications.

Incidence of aortic arch anomalies in patients with thoracic aortic dissections.

BACKGROUND AND AIM OF STUDY: Traditionally aortic arch anomalies have been viewed as a "normal" and clinically insignificant; therefore, they are often overlooked by radiologists and go unreported. Arch anomalies have been reported to occur in 7% to 15% of patients without thoracic aortic aneurysm or dissection. This study aims to define the incidence of aortic arch anomalies in patients with a thoracic aortic dissection (TAD). METHODS: We retrospectively reviewed all patients from 2006 to 2010 with a TAD admitted to a single institution. Thoracic computed tomography images of 176 patients with dissected thoracic aortas and 179 consecutive, unselected age-matched patients without dissection as controls were reviewed to determine the incidence of bovine arch and other arch anomalies. Statistical analysis of demographic data and clinical outcomes was performed to evaluate significant differences between the groups. RESULTS: Arch anomalies occurred in 34% of patients with TAD compared to controls (19%, p = 0.0017). The most common variant was a common origin of the innominate and left common carotid arteries ("bovine" arch) found in 31% of dissection patients compared to 15% in the control group (p = 0.0004). Overall arch anomalies occurred in 27% of all Type A dissections and 39% (p = 0.1409) of all Type B dissections. The association was statistically significant in patients ages 50 to 79 with TAD (36.4%, p = 0.0011) and in African Americans collectively (43.2%, p = 0.0033). CONCLUSIONS: Aortic arch anomalies occur frequently in patients with TAD and therefore may represent a proclivity for this life threatening condition.

Contemporary incidence and risk factors for carotid artery disease in patients referred for coronary artery bypass surgery.

BACKGROUND: In the past decade, there has been an increase in the amount of patients with medical co-morbidities referred for coronary artery bypass surgery (CABG). Significant carotid artery disease in patients undergoing CABG procedures increases the risk of neurological complications. We review the results of routine carotid screening in patients undergoing CABG to determine the contemporary incidence and risk factors for carotid artery disease. METHODS: Between 2008 through 2010, 673 patients were referred for isolated coronary artery bypass surgery at a single institution. Patients were identified through a systematic review of The Department of Cardiothoracic Surgery Society of Thoracic Surgery Outcomes Database. A retrospective analysis of prospectively collected demographic, clinical data and outcomes were performed. All patients with screening preoperative carotid duplex were reviewed. We defined the degree of carotid disease as: none to mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%). Multivariate analysis was performed to identify risk factors. RESULTS: 559 (83%) patients underwent screening preoperative carotid ultrasonography prior to CABG. The incidence of carotid artery disease (>50% stenosis) was 36% with 18% unilateral moderate disease, 10% bilateral moderate and 8% severe disease. Risk factors associated with carotid artery disease included: advanced age, renal failure, previous stroke, peripheral vascular disease, left main coronary artery disease, and previous myocardial infarction. CONCLUSIONS: There is a significant incidence of carotid artery stenosis in patients referred for CABG. Routine screening will identify patients with carotid artery disease and may reduce the risk of postoperative stroke.

Salvage peripheral extracorporeal membrane oxygenation using Cobe Revolution(®) centrifugal pump as a bridge to decision for acute refractory cardiogenic shock.

OBJECTIVES: Acute refractory cardiogenic shock with early multisystem organ failure has a poor outcome without mechanical circulatory support. We review our experience with emergent peripheral cardiopulmonary support as a bridge to decision in these patients. METHODS: A retrospective review from January 2009 through December 2010 was conducted of 26 consecutive adult patients at a single institution with acute refractory cardiogenic shock who underwent salvage peripheral cardiopulmonary support. RESULTS: There were 18 men and 8 women with a mean age of 54 years (range 18 to 76). Indications for support: acute myocardial infarction (n = 16), decompensated chronic heart failure (n = 2), refractory arrhythmic arrest (n = 3), acute valvular pathology (n = 4), and unknown (n = 1). Patients with primary postcardiotomy shock were excluded. Median duration of support was 3 days (range 1 to 14). Decisions included: withdraw of support (n = 4), recovery (n = 5), and bridge to a procedure (n = 17). The procedures were percutaneous coronary intervention (n = 4), left ventricular assist device (n = 9), heart transplantation (n = 1), and miscellaneous cardiac surgery (n = 3). Overall survival to discharge was 65%. In the recovery and bridge to a procedure group, 78% were discharged from the hospital and survival at three months was 72%. CONCLUSIONS: Salvage peripheral cardiopulmonary support is a useful tool to rapidly stabilize acute refractory cardiogenic shock permitting an assessment of neurologic and end-organ viability.

Temporary mechanical circulatory support for Takotsubo cardiomyopathy secondary to primary mediastinal B-cell lymphoma.

BACKGROUND: Left heart mechanical circulatory support (MCS) through the left chest via the pulmonary vein and descending thoracic aorta is a good option for patients with an inaccessible anterior mediastinum and/or poor peripheral access. MATERIALS AND METHODS: We report the case of a 19-year-old small female with a newly discovered bulky primary mediastinal diffuse large B-cell lymphoma (PMBL) who developed refractory inverted Takotsubo cardiomyopathy (TC) with cardiogenic shock. RESULTS: Temporary MCS was implemented in order to stabilize the patient and proceed with a chemotherapy treatment. Given the patient's oncologic "frozen" mediastinum and the presence of poor peripheral arterial access, the left heart temporary MCS was successfully implanted through a left mini-thoracotomy via the left inferior pulmonary vein and descending thoracic aorta. CONCLUSIONS: This is the first report of temporary MCS to treat inverted TC and diffuse PMBL.

Aortic valve replacement in patients with systemic mastocytosis.

Systemic mastocytosis is a hematologic disorder with important perioperative implications. A variety of stimuli and medications can cause severe anaphylaxis in these patients. We report successful preoperative, intraoperative, and postoperative management of a patient with systemic mastocytosis who underwent an aortic valve replacement and review the literature pertaining to cardiac surgery in these patients.

Strategies and outcomes of cardiac surgery in Jehovah's Witnesses.

BACKGROUND: Jehovah's Witnesses (JW) are a Christian faith, with an estimated 1.1 million members in the United States, well recognized for their refusal of blood and blood products. JW may not be considered for cardiac surgery due to perceived higher risks of morbidity and mortality. This study reviews our contemporary strategies and experience with JW undergoing routine and complex cardiac surgery. METHODS: From November 2001 to April 2010, 40 JW were referred for cardiac surgery at a single quaternary referral institution. A retrospective analysis of demographic data, perioperative management, and clinical outcomes was examined. Published validated clinical risk calculator and model for prediction of transfusion were used to identify high-risk patients (risk of mortality >6% or probability of transfusion >0.80). RESULTS: The mean age was 70 (± 9.5) years with 21 men and 19 women. Patients were classified as high risk (45%, n = 18) and low risk (55%, n = 22) with demographics and comorbidities listed in Table 2. Operative procedures included: isolated coronary artery bypass grafting (CABG) (n = 19), isolated valve replacement/repair (n = 7), valve/CABG (n = 7), reoperative valve replacement (n = 4), reoperative CABG (n = 2), valve/ascending aorta replacement (n = 1), and CABG/ascending aorta replacement (n = 1). All JW were evaluated by The Department of Bloodless Medicine to individually define acceptable blood management strategies. The mean preoperative hemoglobin was 14.1 g/dL (±1.6). Overall mortality was 5% (n = 2) all of which were in the high-risk group. DISCUSSION: Using a multidisciplinary approach to blood management, JW can safely undergo routine and complex cardiac surgery with minimal morbidity and mortality.

Thoracic endovascular aortic repair of an aberrant right subclavian artery: technique and long-term outcome.

BACKGROUND: Aberrant right subclavian artery (ARSA) is the most common congenital arch anomaly, which can be complicated by aneursymal dilation at its ostium. We describe a successful repair of an ARSA with a three-stage operative procedure using a left carotid to subclavian bypass, coiling of the ARSA, and thoracic endovascular aortic repair with long-term clinical and radiographic follow-up.

Preoperative statin is associated with decreased operative mortality in high risk coronary artery bypass patients.

BACKGROUND: Statins are widely prescribed to patients with atherosclerosis. A retrospective database analysis was used to examine the role of preoperative statin use in hospital mortality, for patients undergoing isolated coronary artery bypass grafting (CABG.) METHODS: The study population comprised 2377 patients who had isolated CABG at Allegheny General Hospital between 2000 and 2004. Mean age of the patients was 65 +/- 11 years (range 27 to 92 years). 1594 (67%) were male, 5% had previous open heart procedures, and 4% had emergency surgery. 1004 patients (42%) were being treated with a statin at the time of admission. Univariate, bivariate (Chi2, Fisher's Exact and Student's t-tests) and multivariate (stepwise linear regression) analyses were used to evaluate the association of statin use with mortality following CABG. RESULTS: Annual prevalence of preoperative statin use was similar over the study period and averaged 40%. Preoperative clinical risk assessment demonstrated a 2% risk of mortality in both the statin and non-statin groups. Operative mortality was 2.4% for all patients, 1.7% for statin users and 2.8% for non-statin users (p < 0.07). Using multivariate analysis, lack of statin use was found to be an independent predictor of mortality in high-risk patients (n = 245, 12.9% vs. 5.6%, p < 0.05). CONCLUSIONS: Between 2000 and 2004 less than 50% of patients at this institution were receiving statins before admission for isolated CABG. A retrospective analysis of this cohort provides evidence that preoperative statin use is associated with lower operative mortality in high-risk patients.

Outcomes of tricuspid valve repair and replacement: a propensity analysis.

BACKGROUND: The purpose of this study was to compare operative mortality and long-term outcome of patients undergoing tricuspid valve replacement versus tricuspid valve repair. METHODS: From February 1986 to July 2006, 315 patients underwent tricuspid valve surgery including 93 replacements (72 biologic, 21 mechanical) and 222 repairs. To control for selection bias and varying comorbidities, a matched cohort of patients undergoing repair versus replacement was selected using propensity score analysis (68 patients in each group). RESULTS: In the propensity-matched cohorts, operative mortality was similar for tricuspid valve replacement (13% +/- 4%) and repair (18% +/- 5%; p = 0.64). Intensive care unit length of stay was similar between cohorts (replacement, 4 days; repair, 3 days; p = 0.45), but the replacements had a significantly longer hospital lengths of stay (9 days versus 6 days; p = 0.01). In the replacement cohort, survival was 85% at 1 year, 79% at 5 years, and 49% at 10 years. In the repair cohort, survival rates were similar with 80% at 1 year, 72% at 5 years, and 66% at 10 years (p = 0.66 versus replacement). CONCLUSIONS: Surgical treatment of tricuspid valve disease, regardless of the operative approach, is associated with significant early and late mortality. However, there is no difference favoring tricuspid valve repair over replacement. Thus, we should not hesitate to consider tricuspid valve replacement for patients in whom we believe there is a reasonable chance for recurrence of regurgitation after repair.

Outcomes and health-related quality of life after esophagectomy for high-grade dysplasia and intramucosal cancer.

HYPOTHESIS: The reported morbidity and mortality associated with esophagectomy for high-grade dysplasia (HGD) and intramucosal cancer (IMC) have led asymptomatic patients to consider less invasive and possibly less effective treatments. This study provides a critical assessment of outcomes and health-related quality of life (HRQL) after esophagectomy for HGD and IMC. DESIGN: Cohort analytic study. SETTING: Section of thoracic surgery at a tertiary referral center. PATIENTS: All patients who presented between May 1991 and February 2003 with a biopsy-proven diagnosis of Barrett esophagus with HGD or IMC were assessed. MAIN OUTCOME MEASURES: Prospective analysis of postoperative morbidity, mortality, HRQL, and gastrointestinal symptoms. RESULTS: Follow-up was complete in 36 patients. Mean follow-up was 4.9 years (range, 0.5-12.0 years). The incidence of postoperative invasive cancer was 39%, with stages ranging from I to IIB. There were 4 major complications (11%) and no operative mortality. Twenty-eight patients were alive, with a cancer-free survival of 85%. The HRQL outcomes (Medical Outcomes Study 36-Item Short-Form Health Survey) were comparable with those of age- and sex-matched controls. Significant differences in postesophagectomy gastrointestinal symptoms were seen with a decreased incidence of heartburn (P < or = .001) and increased requirement for a slower speed of eating. Twenty-two (79%) of the 28 patients described their current eating pattern as "normal or insignificantly impacted." CONCLUSIONS: Esophagectomy for HGD and IMC can be accomplished with low morbidity and mortality. Furthermore, most patients are able to resume a normal eating pattern, and postoperative HRQL can be equivalent to that of the general population.

The role of epidural anesthesia and analgesia in surgical practice.

OBJECTIVE: To review the potential and proven benefits and complications of epidural anesthesia/analgesia. SUMMARY BACKGROUND DATA: Advances in analgesia/anesthesia have improved patient satisfaction and perioperative outcomes. Epidural anesthesia/analgesia is one of these advances that is gaining rapid acceptance due to a perceived reduction in morbidity and overall patient satisfaction. METHODS: A MEDLINE search was conducted for all pertinent articles on epidural anesthesia/analgesia. RESULTS: Retrospective, prospective, and meta-analysis studies have demonstrated an improvement in surgical outcome through beneficial effects on perioperative pulmonary function, blunting the surgical stress response and improved analgesia. In particular, significant reduction in perioperative cardiac morbidity ( approximately 30%), pulmonary infections ( approximately 40%), pulmonary embolism ( approximately 50%), ileus ( approximately 2 days), acute renal failure ( approximately 30%), and blood loss ( approximately 30%) were noted in our review of the literature. Potential complications related to epidural anesthesia/analgesia range from transient paresthesias (<10%) to potentially devastating epidural hematomas (0.0006%). CONCLUSIONS: Epidural anesthesia/analgesia has been demonstrated to improve postoperative outcome and attenuate the physiologic response to surgery.

Long-term biliary function after reconstruction of major bile duct injuries with hepaticoduodenostomy or hepaticojejunostomy.

HYPOTHESIS: Normal biliary function can be achieved after reconstruction for major bile duct injuries using either hepaticoduodenostomy (HD) or Roux-en-Y hepaticojejunostomy (HJ). DESIGN: Retrospective analysis of consecutive patients requiring biliary enteric reconstructions from February 1, 1993, through January 1, 2002, for bile duct injuries. SETTING: Academic multispecialty referral clinic. PATIENTS: Twenty-seven consecutive patients were evaluated who underwent biliary enteric reconstruction for bile duct injury caused during cholecystectomy. Patients were reconstructed either by HD (18 patients) or HJ (9 patients). INTERVENTIONS: Patients' medical records were reviewed and long-term evaluations were obtained via telephone questionnaire by 2 separate observers (R.J.M. and F.T.L.). Biliary function was evaluated in all using symptoms and liver function test results. Cholangiography was obtained, if indicated clinically. These were reviewed for stricture or dilatation. Any biliary interventions were recorded. MAIN OUTCOME MEASURES: Comparison of long-term biliary function after HD vs HJ reconstructions. RESULTS: All patients were contacted after a median postoperative time of 54 months. Excellent or good results were observed for biliary function in 25 (92%) of the 27 patients. These results were obtained regardless of the type of reconstruction-HD (18 patients) or HJ (9 patients). CONCLUSIONS: We found biliary function to be normal at more than 4 years after biliary-enteric reconstruction for bile duct injury. When surgically feasible, we prefer HD to HJ.