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.

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.

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.

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.

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.

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.

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.

Weathering the storm: how can thoracic surgery training programs meet the new challenges in the era of less-invasive technologies?

OBJECTIVE: The introduction of new technologies has shifted some resident index procedures to nonsurgical specialists. We examined the operative case volume of thoracic surgery residents during the last 6 years to objectively identify changes and trends. METHODS: Program and resident data from 2002 to 2007 were entered into a database and analyzed. Program match information was obtained from the National Resident Matching Program. Resident operative experience and board examination results were obtained from the American Board of Thoracic Surgery. RESULTS: A total of 795 residents qualified for the written American Board of Thoracic Surgery examination; 627 residents graduated from 2-year programs, and 168 residents graduated from 3-year programs. The total number of resident cases was higher in 3-year programs compared with 2-year programs in all 10 index categories studied (P < .01). The total volume of cases has not significantly increased in 2-year programs. The volume of coronary artery bypass graft surgeries decreased in every resident program model studied. The volume of general thoracic cases increased in all program models. Two-year, 2-resident programs had the lowest volume in 5 of the 10 categories, reaching significance in 3 categories. The written board pass rate was lower among 2-year programs than among 3-year programs (86% vs 95%, respectively, P = .003). CONCLUSION: Training programs have so far weathered the storm by maintaining index volume with a new case mix, but significant trends in revascularization procedures are concerning. This study indicates a significant advantage in case volume and board pass rates among 3-year programs. Thoracic residency programs should be reorganized so that the number of residents does not exceed the capacity of the program to provide a meaningful experience.

A perspective on the surgical management of congestive heart failure.

Surgical treatment of patients with congestive heart failure (CHF) has steadily advanced from rescue procedures such as aneurysmectomy, rupture repair, ventricular assist devices (VADs), and transplantation to procedures that can prevent or delay the progression of cardiac dysfunction and failure. The latter include operations such as coronary artery bypass grafting (CABG) and mitral valve repair for patients with ischemic cardiomyopathy (ICMP) and mitral annular dilatation, ventricular restoration and remodeling, and cardiac resynchronization therapy. As the number of heart transplants reported worldwide continues to decline over the past decade (by over 30%), newer surgical therapies have emerged. A need arises for clinical registries such as the NIH-sponsored LVAD registry and registries for biventricular pacing and AICD implantation, for total artificial heart implants, and for mitral valve repair in patients with ICMP. Prospective trials comparing sole ventricular restoration therapy (SVR) to SVR with concomitant CABG/MVR, coronary sinus versus epicardial LV pacing for ventricular resynchronization therapy, trials comparing LVAD as destination therapy to AICD implants, mitral valve repair versus chordal-sparing valve replacement for ischemic and valvular cardiomyopathy, and off-pump versus on-pump CABG for patients with ICMP are urgently needed. Future research should also be directed toward drugs targeting "B-cell mediated" humeral vascular rejection--the Achilles heel of cardiac transplantation, xenotransplantation, permanently implantable VADs, gene therapy, and myocardial cell regeneration therapy.

Progress towards a more physiologic approach to donor heart preservation: the advantages of hyperpolarized arrest.

BACKGROUND: The University of Wisconsin (UW) solution is the gold standard for heart preservation but has limitations in terms of both duration and adequacy of protection. Our laboratory has been interested in a more physiologic approach to heart preservation by maintaining the heart at its resting membrane potential (hyperpolarized arrest) with the K(ATP) channel agonist pinacidil. This study compared our extracellular solution (WashU) with the UW intracellular depolarizing solution and quantified the protective effect of pinacidil in both solutions. METHODS: Thirty-two rabbit hearts received 1 of 4 solutions in a crystalloid-perfused Langendorff apparatus: (1) UW, (2) WashU containing 0.5 mmol/liter pinacidil, (3) UW with 0.5 mmol/liter pinacidil, or (4) WashU without pinacidil. Thirty minutes of perfusion was followed by data acquisition consisting of left ventricular pressure-volume curves generated by inflating an intraventricular balloon. All hearts were placed in cold storage for 8 hours, followed by 1 hour of reperfusion before data acquisition. RESULTS: Post-ischemic developed pressure (DP) was better preserved by WashU (76.8% +/- 3.8%) than by UW (48.3% +/- 2.5%). Diastolic compliance was better preserved by WashU (239.9% +/- 77.2%) compared with UW (711.1% +/- 193.1%). Removing pinacidil from our solution resulted in decreased DP (46.6% +/- 3.2%) and diastolic compliance (688.8% +/- 158.2%) Adding pinacidil to UW had a limited effect on DP and compliance. CONCLUSIONS: Our results support the superiority of the WashU hyperpolarizing solution for heart preservation over UW. Pinacidil was beneficial in maintaining cardiac function and compliance. This benefit was not observed when pinacidil was placed into the UW depolarizing solution.

Comparison of skill training with robotic systems and traditional endoscopy: implications on training and adoption.

BACKGROUND: Robotic systems are being used by an increasing number of surgeons. This environment is markedly different from that of traditional surgery and involves videoscopic guidance, remote surgical control, and the loss of haptic feedback. Defining how surgeons learn with these systems is necessary to establish training protocols for this technology. This study compared the learning curve for a robotic surgical system with that of traditional endoscopy in the performance of two standardized skill drills. MATERIALS AND METHODS: Twenty participants (average age 27 +/- 4 years, six females) repeated two standardized endoscopic dexterity and depth perception drills for 15 repetitions with the ZEUS robotic surgical system and manual endoscopic instruments (MAN). A score combining time and precision was given for each repetition. The learning curves and overall performance with and without robotic assistance were compared. RESULTS: For both MAN and ZEUS, improvements in performance were significantly greatest during the first five repetitions (P < 0.01, for both). Participants reached the training curve plateau faster with ZEUS than with conventional instruments (8th versus 10th for both drills). Using robotic assistance, dominant and non-dominant hand performance were statistically similar. The number of errors committed with ZEUS were significantly fewer for drill two (0.09 errors/repetition versus 0.24 errors/repetition, P = 0.002) compared to manual technique. CONCLUSIONS: This study demonstrated that training curves for conventional and robotic-assisted systems are remarkably similar. This should prove useful in the training and education of this new technology. This study further suggested that robotics may increase ambidexterity by improving non-dominant hand performance.

Reservoir and conduit function of right atrium: impact on right ventricular filling and cardiac output.

The purpose of this study was to investigate the relationship between right atrial (RA) reservoir and conduit function and to determine how hemodynamic changes influence this relationship and its impact on cardiac output. In 11 open-chest sheep, RA reservoir and conduit function were quantified as RA inflow with the tricuspid valve closed versus open, respectively. Conduit function was separated into early (before A wave) and late (after A wave) components. The effects of inotropic stimulation, partial pulmonary artery occlusion, and pericardiotomy were tested. At baseline with the pericardium intact, reservoir function accounted for 0.56 (SD 0.13) of RA inflow, early conduit for 0.29 (SD 0.07), and late conduit (during RA contraction) for 0.16 (SD 0.11). Inotropic stimulation decreased conduit function and increased reservoir function, but these effects did not reach statistical significance. With partial pulmonary artery occlusion, early conduit function fell to 0.20 (SD 0.11) (P < 0.04), and the conduit-to-reservoir ratio decreased by 41% (P < 0.03). Similarly, after pericardiotomy, early conduit function fell to 0.14 (SD 0.09) (P < 0.004), reservoir function increased to 0.72 (SD 0.08) (P < 0.04), and, consequently, the early conduit-to-reservoir ratio decreased by 63% (P < 0.006). Cardiac output was inversely related to the conduit-to-reservoir ratio (r = 0.39, P < 0.001). This study demonstrated that the right atrium adjusts its ability to act more as a reservoir than a conduit in a dynamic manner. The RA conduit-to-reservoir ratio was directly related to the right ventricular pressure-RA pressure gradient at the time of maximum RA volume, with increased ventricular pressures favoring conduit function, but it was inversely related to cardiac output, with an increase in the reservoir contribution favoring improved cardiac output.

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.

A prospective multicenter trial of bipolar radiofrequency ablation for atrial fibrillation: early results.

BACKGROUND: The Cox-Maze III remains the gold standard for the surgical treatment of atrial fibrillation. However, the "cut-and-sew" technique is time consuming and technically challenging. The pulmonary veins are the source of ectopy in the majority of patients with atrial fibrillation. The safety and efficacy of bipolar radiofrequency to electrically isolate the pulmonary veins was evaluated in a prospective multi-center trial. METHODS: Beginning in January 2002, 30 patients at three medical centers underwent pulmonary vein isolation using bipolar radiofrequency and were followed for 6 months. Twenty-four of the patients also underwent a modified Cox-Maze III. Electrical isolation of the pulmonary veins was confirmed with intraoperative pacing. Pulmonary vein patency was assessed by magnetic resonance imaging or three-dimensional computed tomography in 15 patients at 1 month. RESULTS: Mean age was 60.9 +/- 11.7 years. Nineteen patients had paroxysmal atrial fibrillation. All pulmonary veins were isolated in every patient. The left pulmonary veins underwent 3.0 +/- 1.4 applications for a total of 26.4 +/- 10.5 seconds. The right pulmonary veins underwent 2.8 +/- 1.1 applications for a total of 26.3 +/- 12.6 seconds. There was no operative mortality. At 1 month, imaging revealed no evidence of pulmonary vein stenosis. At 6 months, 96% of patients were in normal sinus rhythm. CONCLUSIONS: The use of bipolar radiofrequency for electrical isolation of pulmonary veins and to replace other Cox-Maze III incisions is safe and effective at controlling atrial fibrillation. This emerging technology may shorten and simplify the surgical management of atrial fibrillation.

Successful performance of Cox-Maze procedure on beating heart using bipolar radiofrequency ablation: a feasibility study in animals.

BACKGROUND: The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation with proven long-term efficacy. However, its application has been limited by its complexity and significant morbidity. The purpose of this study was to test the feasibility and safety of performing the Cox-Maze procedure using bipolar radiofrequency ablation on the beating heart without cardiopulmonary bypass. METHODS: After median sternotomy, 6 Hanford mini-pigs underwent a modified Cox-Maze procedure using bipolar radiofrequency energy. The animals survived for 30 days. Atrial function, coronary artery, pulmonary vein anatomy, and valve function were assessed by magnetic resonance imaging. At reoperation, pacing documented electrical isolation of the pulmonary veins. Induction of atrial fibrillation was attempted by burst pacing with cholinergic stimulation. Histologic assessment was performed after sacrifice. RESULTS: There were no perioperative mortalities or neurologic events. At 30 days, atrial fibrillation was unable to be induced, and pulmonary vein isolation was confirmed by pacing. Magnetic resonance imaging assessment revealed no coronary artery or pulmonary vein stenoses. Although atrial ejection fraction decreased slightly from 0.344 +/- 0.0114 to 0.300 +/- 0.055 (p = 0.18), atrial contractility was preserved in every animal. Histologic assessment showed all lesions to be transmural, and there were no significant stenoses of the coronary vessels or injuries to the valves. CONCLUSIONS: Virtually all of the lesions of the Cox-Maze procedure can be performed without cardiopulmonary bypass using bipolar radiofrequency energy. There were no late stenoses of the pulmonary veins. Clinical trials of this new technology on the beating heart are warranted.