Transcatheter aortic valve replacement in left ventricular assist device patient-overcoming the complications with transapical approach and circulatory arrest.

We present the patient with severe aortic insufficiency (AI) 5 years post left ventricular assist device (LVAD) implantation. His management was complicated with unsuccessful percutaneous aortic valve closure attempt, transcatheter aortic valve replacement (TAVR) implantation with a severe paravalvular leak, eventual valve dislodgment into the left ventricle (LV), and LVAD inflow cannula occlusion. We utilized a mini-thoracotomy approach to successfully retrieve the dislodged valve through the LV apex while deploying a valve-in-valve TAVR under direct visualization and deep hypothermic cardiac arrest. This case can serve as an example of the serious pitfalls and potential resolution strategies when treating LVAD-associated AI.

Direct right ventricular Impella LD implantation enables postoperative ambulation and may avoid sternal re-entry.

Right ventricular assist devices (RVADs) typically require groin cannulation or sternal re-entry which can be avoided by direct pulmonary artery implantation with an Impella. We report the first use of the Impella LD as a directly implanted RVAD.

Robotic thoracic surgery: an evolution in progress for the treatment of lung cancer.

The field of robotic thoracic surgery has exploded in the last five years. Robotic technology allows the surgeon to perform complex operations with smaller incisions. As robotic systems become smaller, more efficient and the surgeons gain more experience, the results will continue to improve. The goal is less trauma to the patient which will decrease hospital stay, complications and lower health care costs, while allowing faster healing and productivity.

A Novel Subxiphoid Approach for Bilateral Internal Thoracic Artery Harvesting.

OBJECTIVE: Bilateral internal thoracic artery (BITA) bypass can enable more complete arterial revascularization procedures. Minimally invasive cardiac surgery (MICS) can offer significant patient benefits. New minimally invasive technology for sternal retraction and tissue manipulation is needed to enable ergonomic and reliable minimally invasive ITA harvesting. The goal of this research was to develop technology and techniques, along with experimental testing and training models, for a sternal-sparing approach to in situ BITA harvesting through a small subxiphoid access site. METHODS: This study focused on optimizing custom equipment and methods for subxiphoid BITA harvesting initially in a porcine model (19 pig carcasses, 36 ITAs) and subsequently in 7 cadavers (14 ITAs). RESULTS: Fifty consecutive ITAs were successfully harvested using this remote access approach. The last 20 ITA specimens harvested from the porcine model were explanted and measured; the average length of the free ITA grafts was 12.8 ± 0.9 cm (range 10.8 to 14.2 cm) with a mean time of 23.3 ± 5.2 minutes (range 13 to 25 minutes) for each harvest. CONCLUSIONS: Early results demonstrate that both ITAs can be reliably harvested in a skeletonized fashion in situ through sternal-sparing, small subxiphoid access in 2 experimental models. This innovative approach warrants further exploration toward facilitating complete arterial revascularization and the further adoption of minimally invasive coronary artery bypass graft surgery.

Current outcomes of simultaneous carotid endarterectomy and coronary artery bypass graft surgery in North America.

OBJECTIVE: Management of patients with concomitant carotid and coronary artery disease has been controversial. Divergent strategies have been employed, including simultaneous carotid endarterectomy and coronary bypass (SCC) versus various staged procedures. Although no strict comparison group is available, this study defines current outcomes of SCC, compared qualitatively to two reference categories. METHODS: Utilizing the STS database from 2003 to 2007, patients who had SCC were compared with patients with cerebrovascular disease who had coronary bypass (CABG) with prior carotid endarterectomy (CEA), and those with carotid Doppler stenosis >75% and no carotid intervention. Logistic regression analysis adjusted for differences in baseline characteristics and operative mortality (OM), and a composite of neurological complications (NC) was assessed. RESULTS: Of 745,769 patients who underwent isolated CABG with/without CEA, 108,212 (14%) had cerebrovascular disease. Of this group, 5,732 (5%) underwent SCC. The SCC group had more males and lower preoperative risk factors. After statistical adjustment for all baseline differences, SCC had clinically and statistically higher OM and NC compared with any of the reference groups, with 20-40% higher event risk. CONCLUSIONS: Although no quantitative control group exists for comparison, SCC as recently performed in North America has a high risk compared with any of the reference groups. Suboptimal results associated with the SCC strategy suggest a need for quality improvement and research on the optimal management of patients with simultaneous carotid and coronary disease.

Towards detection of brain injury using multimodal non-invasive neuromonitoring in adults undergoing extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary bypass that provides life-saving support to critically ill patients whose illness is progressing despite maximal conventional support. Use in adults is expanding, however neurological injuries are common. Currently, the existing brain imaging tools are a snapshot in time and require high-risk patient transport. Here we assess the feasibility of measuring diffuse correlation spectroscopy, transcranial Doppler ultrasound, electroencephalography, and auditory brainstem responses at the bedside, and developing a cerebral autoregulation metric. We report preliminary results from two patients, demonstrating feasibility and laying the foundation for future studies monitoring neurological health during ECMO.

Chronic transmural atrial ablation by using bipolar radiofrequency energy on the beating heart.

BACKGROUND: Recently, there has been renewed interest in the development of minimally invasive procedures to treat atrial fibrillation. Unipolar radiofrequency catheters are plagued by poor results, in part because of their inability to produce transmural lesions. This study tested the ability of bipolar radiofrequency energy to create chronic transmural lesions on the beating heart that isolated atrial myocardium. METHODS: Five sheep underwent a right thoracotomy. Baseline pacing was performed from the following targeted areas: right atrial appendage, superior vena cava, inferior vena cava, and right pulmonary veins. A cuff of atrial myocardium around the targeted tissue was clamped between the 2 arms of the device. Radiofrequency energy was delivered at 750 mA and continued until the tissue conductance between the electrodes reached a stable minimum level. After ablation, pacing was used to document tissue isolation. The animals survived for 30 days. RESULTS: Twenty circumferential lesions were produced at the initial operation. The mean ablation time was 9.3 +/- 4.0 seconds, and the mean peak temperature was 48.4 degrees C +/- 6.4 degrees C. All lesions acutely and chronically isolated the targeted tissue. Trichrome staining showed that all lesions were transmural. There were no instances of pulmonary vein stenosis or thrombosis. CONCLUSIONS: Bipolar radiofrequency energy can produce permanent transmural linear lesions on the beating heart. Online measurement of tissue conductance reliably predicted lesion transmurality. This new technology may enable surgeons to perform a curative minimally invasive operation for atrial fibrillation on the beating heart.

The Cox maze III procedure for atrial fibrillation: long-term efficacy in patients undergoing lone versus concomitant procedures.

BACKGROUND: For the last decade, the Cox maze III procedure has been available for the treatment of atrial fibrillation. It is unknown whether the operation has similar efficacy in patients with lone atrial fibrillation compared with that in patients with atrial fibrillation associated with coronary, valve, or congenital heart disease. This study examined the long-term outcome of patients who underwent this procedure either as a lone operation or as a concomitant procedure. METHODS: From 1988 to 2001, 198 patients underwent a Cox maze III procedure; 112 were lone operations, and 86 were concomitant procedures. Major complications included renal failure, reoperation for bleeding, mediastinitis, stroke, and balloon pump insertion. Follow-up was performed by means of mail and telephone questionnaires with both the patients and their cardiologists. All patients who had any history of arrhythmia or who were taking medication had their rhythm documented by means of electrocardiography. RESULTS: The lone operation group was significantly younger (51.3 +/- 10.5 vs 58.8 +/- 9.9 years) and had a higher male/female ratio (4:1 vs 2:1). There was no difference in operative mortality between groups (1.8% vs 1.2%). At a follow-up of 5.4 +/- 2.9 years, 96.6% (172/178) of all patients were free of atrial fibrillation. There was no difference between the lone operation and concomitant procedure groups (95.9% vs 97.5%). CONCLUSION: The Cox maze III procedure has equivalent operative risk and long-term efficacy in patients undergoing both lone operations and concomitant procedures. The Cox maze III procedure remains the standard against which alternative procedures for atrial fibrillation must be judged.

Effect of target stenosis and location on radial artery graft patency.

OBJECTIVE: The purpose of this study was to evaluate the effect of target vessel characteristics on radial artery patency when used as a composite T graft. METHODS: Between October 1993 and March 2001, 1022 patients underwent coronary bypass with the internal thoracic artery-radial artery composite T graft. Of these, angiography has been performed on 109 patients at a mean 27.1 months (range, 2-70 months) postoperatively for symptoms of ischemia. By means of Cox proportional hazard models, the relationships between anastomotic patency and target vessel location, proximal stenosis, target diameter, and quality were assessed. RESULTS: A total of 231 radial artery anastomoses were evaluated. The mean stenosis for patent anastomoses was 82% compared with 71% for occluded anastomoses (P <.001). Anastomotic patency for targets with moderate stenosis (< or = 70%) was worse than that for vessels with critical stenosis (> or = 90%; relative risk, 1.7; 95% confidence interval, 1.3-2.2; P <.001). Patency for targets of the right coronary artery was statistically inferior to that for targets of the left anterior descending artery (relative risk, 1.8; 95% confidence interval, 1.2-2.9; P =.01) and bordered on significance versus that for the circumflex artery distribution (relative risk, 1.6; 95% confidence interval, 1.0-2.8; P =.06). When directed toward critically stenosed targets of the left anterior descending or circumflex arteries, radial artery patency was not statistically different that that of the internal thoracic artery (P =.19). CONCLUSION: Radial artery patency is sensitive to both target location and proximal target stenosis. Selective use of the radial artery to targets of the left anterior descending and circumflex distributions remains encouraging. Radial artery grafts to targets of the right coronary artery or those with moderate stenosis appear to be at particularly high risk of failure.

A prospective, single-center clinical trial of a modified Cox maze procedure with bipolar radiofrequency ablation.

OBJECTIVE: The Cox maze III procedure has excellent long-term efficacy in curing atrial fibrillation. It has not been widely practiced because it is technically challenging and requires prolonged cardiopulmonary bypass. The aim of this study was to examine a simplified Cox maze III procedure that uses bipolar radiofrequency energy as an ablative source. METHODS: Beginning January 2002, a total of 40 consecutive patients underwent a modified Cox maze III procedure with bipolar radiofrequency energy. Nineteen had a lone maze procedure and 21 had a maze procedure plus a concomitant operation. One month after the operation, the first 8 patients were investigated with high-resolution magnetic resonance imaging. Patients were followed up monthly with clinical examination and electrocardiography. RESULTS: There was no operative deaths. The crossclamp times were 47 +/- 26 minutes for the modified lone Cox maze III procedure and 92 +/- 37 minutes for the Cox maze III procedure plus concomitant procedures. These were significantly shorter than our previous times for the traditional Cox maze III procedure (93 +/- 34 minutes and 122 +/- 37 minutes, respectively, P <.05). Follow-up magnetic resonance imaging showed no evidence of pulmonary vein stenosis, and atrial contractility was preserved in all patients. There were no late strokes. At 6-month follow-up, 91% of patients (21/23) were in sinus rhythm. CONCLUSIONS: Bipolar radiofrequency ablation can be used to replace the surgical incisions of the Cox maze procedure. This energy source did not result in pulmonary vein stenosis. The modification of the Cox maze III procedure to use bipolar radiofrequency ablation simplified and shortened this procedure without sacrificing short-term efficacy.

Physiological consequences of bipolar radiofrequency energy on the atria and pulmonary veins: a chronic animal study.

BACKGROUND: Alternative energy sources have been proposed for the transvenous and surgical treatment of atrial fibrillation. This study examined the physiologic consequences of a novel energy source, bipolar radiofrequency energy, in a chronic animal model in order to determine its ability to produce transmural lesions on the beating heart. METHODS: Five dogs underwent baseline pacing from the following target areas: right and left atrial appendage, superior and inferior vena cavae, and right and left pulmonary veins. A cuff of atrial myocardium, proximal to the target tissue was clamped and ablated between the arms of the bipolar radiofrequency energy device. Tissue conductance was used as a transmural indicator. After ablation, the pacing protocol was repeated. Baseline and postablation pulmonary vein flows were measured. Animals were survived for 30 days, and permanent electrical isolation was evaluated by pacing, epicardial mapping, and histology. RESULTS: Mean ablation time was 5.0 +/- 1.8 seconds and mean peak tissue temperature was 46.7 degrees C +/- 2.8 degrees C. All lesions (30/30) acutely and permanently isolated atrial tissue. There was no change in pulmonary vein flow. Mapping studies with pacing of atrial tissue on both sides of the lesion confirmed isolation. Histology demonstrated that all lesions were linear, continuous, and transmural with no thrombus formation or stenosis. CONCLUSIONS: Bipolar radiofrequency energy rapidly produced permanent transmural linear lesions on the beating heart. Measurement of tissue conductance reliably predicted transmural lesions. This new technology may enable the development of a less invasive, surgical approach to atrial fibrillation.

Delayed paraplegia after thoracic and thoracoabdominal aneurysm repair: a continuing risk.

BACKGROUND: Paraplegia or paraparesis after otherwise successful thoracic or thoracoabdominal aortic reconstruction is a devastating complication for patient and physician. Interventions for its prevention have focused primarily on the intraoperative period. We have recently noted a significant incidence of delayed-onset neurologic deficit. METHODS: We reviewed our most recent 5-year experience with thoracic and thoracoabdominal reconstruction to examine the incidence of and potential contributors to delayed paraplegia or paraparesis. RESULTS: Between June 1996 and June 2001, 60 patients (29 men, 31 women) underwent repair of isolated thoracic (n = 26) or thoracoabdominal aortic aneurysm (Crawford I, n = 7; Crawford II, n = 14; Crawford III, n = 12; Crawford IV, n = 1) by the cardiac and vascular surgical services collaboratively. Repair was performed endovascularly in 6, and open with either circulatory arrest in 12, partial left heart bypass in 37, or partial femorofemoral bypass in 5. Operative mortality was 9.3% (5 of 54 patients) for open repair and 0% for endovascular repair. Paraplegia or paraparesis occurred in 6 (10%) patients of which 83.3% (5 of 6) were delayed in onset. All patients with delayed paraplegia or paraparesis had degenerative aneurysms of Crawford extent II (n = 3) or III (n = 2), had intraoperative left heart bypass, and had perioperative spinal drainage. Delayed paraplegia or paraparesis occurred up to 27 days postoperatively, and was associated with a documented episode of hypotension in 60% (3 of 5) of patients. CONCLUSIONS: Improvements in intraoperative management may have reduced immediate paraplegia or paraparesis among vulnerable patients only to leave them at risk of delayed-onset deficit. Postoperative care, including assiduous attention to avoidance of even transient hypotension, must be tailored to this patient population.

Radial artery patency: are aortocoronary conduits superior to composite grafting?

BACKGROUND: The radial artery (RA) can be used as either an aortocoronary (RA-Ao) or composite graft (T graft). Optimum use for the RA has yet to be established. We compared RA patency with these two techniques. METHODS: Between October 1993 and June 2001, 1505 patients underwent coronary artery bypass grafting using the RA as either a composite (n = 1022) or RA-Ao graft (n = 483). Angiograms performed on 203 (13.5%) patients with signs or symptoms of ischemia at an average of 26.1 +/- 18.5 months postoperatively were reviewed. RESULTS: Patients with RA-Ao grafts had a greater incidence of postoperative angiography versus patients with composite grafts (19% versus 11%; p < 0.01). Patients receiving T grafts had a greater number of anastomoses per patient (4.1 +/- 0.6 versus 3.0 +/- 1.0; p < 0.01) and a higher incidence of total arterial revascularization (100% versus 41%; p < 0.01). Regardless of grafting strategy, patency was significantly worse for targets of the right coronary artery (58% T graft; 67% RA-Ao; p < 0.01 for both) and for targets with less than or equal to 70% stenosis (59% T graft; 57% RA-Ao; p < 0.01 for both). The site of proximal anastomosis failed to effect RA patency (relative risk, 1.2; 95% confidence interval, 0.7 to 1.8; p = 0.50). CONCLUSIONS: The site of the proximal anastomosis does not appear to influence patency. Both RA-Ao and composite conduits are sensitive to target location and stenosis. Advantages of composite grafting include greater conduit length and minimizing aortic manipulation at the expense of increased complexity and the potential for hypoperfusion. These factors should be considered when choosing an RA grafting strategy.

Surgical robotics: impact of motion scaling on task performance.

BACKGROUND: Robotic systems have been shown to enhance surgical dexterity, and the advantage has been hypothesized to result from the removal of tremor and addition of motion scaling. But these purported gains over traditional laparoscopic instrumentation have not been quantified. This study was designed to compare the surgical accuracy between conventional laparoscopic instruments and a robotic surgical system and evaluate the importance of tremor filtration (TF) and motion scaling (MS) in these robotic systems. STUDY DESIGN: Fifteen participants with no previous surgical experience were enrolled. To simulate microsurgical techniques, a 29-gauge needle was used to puncture the center of 6 microscopic archery targets (circle diameters 0.5, 1.5, and 2.5 mm). The robotic system was configured to three different degrees of MS and compared with the unassisted laparoscopic platforms in accuracy. RESULTS: Accuracy with robotic assistance with TF alone (1:1 MS) was not significantly different from unassisted laparoscopic control. Both moderate (2.5:1) and fine (7:1) MS significantly improved accuracy over traditional laparoscopic control (p < 0.001 for both). Robotic assistance with MS equalized the performance of both hands (p = 0.03) in precision, and manual laparoscopy demonstrated no statistical difference in handedness (p = 0.80). CONCLUSIONS: Motion scaling, rather than tremor filtration, plays the major role in the enhanced accuracy seen in robotic surgical systems. Robotic assistance with MS significantly improved accuracy above laparoscopic instruments alone and robotic assistance with tremor filtration alone. MS also creates ambidexterity in an otherwise unidextrous population, optimizing the surgeon's ability to undertake tasks requiring microsurgical accuracy.

The effect of robotic assistance on learning curves for basic laparoscopic skills.

BACKGROUND: We hypothesized that laparoscopic tasks performed with ZEUS robotic assistance would be done with greater precision and with a different learning curve than when performed in a standard laparoscopic trainer. METHODS: Participants were divided into the surgically experienced (n = 11) and the surgically naive (n = 17). Two laparoscopic tasks (bead transfer and rope pass) were repeated for five repetitions. RESULTS: For all drills and participants, completion time and error rate decreased across the five repetitions for each platform. Precision averaged 97% for both platforms over all drills. For both groups, completion time for tasks was shorter on the laparoscopic platform. ZEUS allowed for greater consistency in performance. CONCLUSIONS: Compared with performance on a standard laparoscopic trainer, robotic assistance allows for increasing speed and consistency while maintaining precision over multiple repetitions. Understanding how robotics affects learning curves will allow for modifications in the training experience with this new technology.

The use of eptifibatide for suspected pump thrombus or thrombosis in patients with left ventricular assist devices.

BACKGROUND: Pump thrombosis in patients with left ventricular assist devices (LVADs) continues to present treatment challenges. Anti-coagulation strategies used to treat this complication are empiric and without firm data for guidance. The addition of a platelet glycoprotein IIb/IIIa inhibitor to intravenous anti-coagulation has been suggested by several case series and recent guidelines. The aim of this study was to evaluate our use of eptifibatide for the treatment of suspected pump thrombus/thrombosis. METHODS: This retrospective, single-center cohort study was performed at Barnes-Jewish Hospital. The medical informatics system was queried to identify all LVAD patients who received eptifibatide for suspected pump thrombus/thrombosis from January 1, 2011, through April 30, 2013. RESULTS: A total of 17 patients (16 HeartMate II [Thoratec, Pleasanton, CA], 1 HeartWare [HeartWare International Inc, Framingham, MA]) with 22 separate administration attempts received eptifibatide (dose range, 0.1-2 µg/kg/min) for suspected pump thrombus/thrombosis presenting as one or more of the following findings: elevated lactate dehydrogenase, decreased haptoglobin, elevated plasma free hemoglobin, LVAD dysfunction, or new, persistently high LVAD power. The mean time from device implantation to eptifibatide therapy was 47.34 days (range, 3.88-397.67 days). Of the 22 attempts, 5 (22.7%) resulted in resolution of 1 or more patient-specific indicators of LVAD thrombus/thrombosis. Three patients (17.6%) had resolution of an indicator while also remaining free from continued hemolysis, death, pump exchange, or emergent heart transplant. Bleeding events were common, with 11 patients (64.7%) experiencing bleeding during the infusion. Seven patients (41.2%) died, with intraparenchymal hemorrhage as the cause of death in 2 patients. Pump exchange was performed in 3 patients. CONCLUSIONS: Our limited experience indicates the risk of using eptifibatide outweighs the proposed benefit of salvaging the existing LVAD in the setting of suspected pump thrombus/thrombosis at our institution.

Thirty-five day Impella 5.0 support via right axillary side graft cannulation for acute cardiogenic shock.

We describe the use of an Impella 5.0 for mechanical support in acute cardiogenic shock after an acute myocardial infarction. A 61-year-old man with a history of severe coronary artery disease who underwent coronary artery bypass grafting with ischemic cardiomyopathy presented with cardiogenic shock after an ST-elevation myocardial infarction. An Impella Recover LP 5.0 (Abiomed, Danvers, MA USA) was inserted via a right axillary side graft, using transesophageal echocardiographic and fluoroscopic guidance. The patient remained in the intensive care unit, where he required a tracheostomy to be weaned off the ventilator. He required renal replacement therapy with subsequent complete recovery. His Impella support was weaned, and on postoperative day 35, the device was removed. The patient developed axillary thrombosis the morning after removal, requiring thrombectomy. Discharge echocardiogram showed mild left ventricular enlargement with global hypokinesis and left ventricular ejection fraction of 25%. The Impella 5.0 device can safely and effectively be used in the long-term support of cardiogenic shock.