Oliver Reuthebuch

Advanced training model for beating heart coronary artery surgery: the Zurich heart-trainer

OBJECTIVEnCoronary artery surgery with beating heart technique is gaining increasing popularity. However, it is a challenging technique even for well-trained cardiac surgeons. Thus, a training model for beating heart surgery was developed to increase safety and accuracy of this procedure.nnnMETHODSnThe model consists of differentially hardened polyurethane resembling mechanical properties of the human heart. The covering used in this model is a 1:1 replica of the human thoracic wall with optionally embedded skeletal structures. Sternotomy, lateral thoracotomy or trocar placement is possible to access the lungs, the pericardium and the heart with adjacent vessels. Disposable artificial coronaries variable in size, wall quality or wall thickness are embedded in the synthetic myocardium. Two-layer vessels, which can simulate dissection, are available. Bypass conduits utilize the same material. Coronaries/bypasses as well as part of the ascending aorta are water-tight and can be rinsed with saline. Lungs can be inflated. A purpose-built pump induces heart movement with adjustable or randomized stroke volume, heart rate and arrhythmia induction.nnnRESULTSnThe model was tested in a recent Wet-Lab course attended by 30 surgeons. All conventional instruments and stabilizers with standard techniques can be used. Training with beating or non-beating heart was possible. Time needed for an anastomosis was similar to clinical experience. Each artificial tissue showed its individual nature-like qualities. Various degrees of difficulty can be selected, according to stroke volume, heart rate, arrhythmia, vessel size and vessel quality. The model can be quickly and easily set up and is fully reusable.nnnCONCLUSIONSnThe similarity to human tissue and the easy set-up make this completely artificial model an ideal teaching tool to increase the confidence of cardiac surgeons dealing with beating heart and minimally invasive surgery.

Graft occlusion after deployment of the Symmetry Bypass System.

Recently the Symmetry Bypass System (SJM, St. Paul, MN) became available. Now the system is frequently applied for vein-graft to aorta anastomoses in off-pump coronary artery bypass operations. This report describes a complication associated with the use of the Symmetry Bypass System (SJM) in a patient undergoing a standard off-pump coronary artery bypass procedure. A novel imaging system (SPY, Novadaq, Toronto, Canada) was applied for intraoperative assessment of graft function, and this system immediately diagnosed the occlusion of the proximal mechanical anastomosis caused by a mobile atheromatous aortic plaque.

Experiences in robotically enhanced IMA-preparation as initial step towards totally endoscopic coronary artery bypass grafting.

AIMnTo evaluate the feasibility of robotically enhanced preparation of internal mammary arteries (IMA).nnnMETHODnVia three trocars in left thoracic wall the left, right or both IMA were skeletonized under CO(2) insufflation and single lung ventilation using electrocautery.nnnRESULTSnIn 12 months, 26 LIMA, five BIMA and one RIMA were dissected. In five patients, the procedure had to be determined (IMA injury (two), respiratory insufficiency (two), and heart penetration (one)). Mean intrathoracic pressure was 9.7+/-1.5 mmHg. Mean time for LIMA and RIMA dissection was 66.7+/-21.1 and 99.2+/-8.7 min, respectively. In 10 patients, pericardium was incised and course of LAD assessed. However, in two patients, this coronary did not correlate with LAD. Time for instrument change depended on type of tool (cautery blade: 24.9+/-13.1 s, clip applier 72.8+/-28.4 s).nnnCONCLUSIONnRobotic dissection of IMA is reasonable. However, life-threatening complications can barely be managed due to inadequate tools and excessive time for instrument change. Incorrect determination of coronaries can result in misplaced anastomoses.

Less Invasive Surgical Treatment of Renal Cell Carcinomas Extending into the Right Heart and Pulmonary Arteries: Surgery for Renal Cell Carcinoma

Background: Radical resection using deep hypothermic circulatory arrest improves the survival of patients with transvenous intracardiac tumor extension of renal cell carcinomas. A less invasive surgical approach avoiding deep hypothermia, circulatory arrest, and cross‐clamping of the aorta is presented. Methods: Between 1987 and 1999, 12 patients (mean age 57 ± 8 years) underwent resection of a renal cell carcinoma extending into the right atrium, right ventricle, or pulmonary arteries. After median sterno‐laparotomy, nor‐mothermic cardiopulmonary bypass is used cannulating the ascending aorta, superior caval vein, and inferior caval vein below the renal veins. The tumor and the corresponding kidney are radically excised, including the renal vein. Tumor fragments from the inferior caval vein, the right heart, and pulmonary arteries are removed either on the fibrillating or beating heart. Results: Operative mortality was 0%. Mean cardiopulmonary bypass time was 53 ± 27 minutes (median 36; range 32–110 minutes). Mean blood loss per patient was 1200 mL. Mean duration of postoperative mechanical ventilation was 36 ± 12 hours (median 36; range 30–77 hours), mean intensive care stay 5.5 ± 5 days (median 3; range 1–48 days), and mean duration of hospitalization 22 ± 12 days (median 21; range 10–58 days). All patients were discharged home. Patients with multiple tumor manifestations outside the cardiovascular systems died within 9 months after the operation. Conclusions: The use of normothermic cardiopulmonary bypass is a less invasive method for radical resection of renal cell carcinoma with intracardiac tumor extension. Radical resection does not improve survival in patients with multiple distant metastases.

Total robotic-enhanced pericardiectomy for effusive pericarditis

With the DaVinci Robot only recently in clinical use, limitations of video-assisted thoracoscopy could disappear due to Endo-Wrist features, tremor cancellation and three-dimensional view. This report describes the total endoscopic pericardiectomy successfully achieved with robotic assistance in a 50-year-old man suffering from effusive pericarditis.

Proteomics highlights decrease of matricellular proteins in left ventricular assist device therapy

OBJECTIVESnWe investigated the impact of mechanical unloading with a left ventricular assist device (LVAD) on the myocardial proteome.nnnMETHODSnWe collected 11 patient-matched samples of myocardial left ventricular tissue of patients with non-ischaemic dilate cardiomyopathy, harvested at time of LVAD implant (pre-LVAD) and heart transplant (post-LVAD). Samples were studied by quantitative proteomics. Further we performed histological assessment of deposited collagens and immune infiltration in both pre- and post-LVAD samples.nnnRESULTSnA core set of u2009>1700 proteins was identified and quantified at a false discovery rate u2009<1%. The previously established decrease post-LVAD of alpha-1-antichymotrypsin was corroborated. We noted a post-LVAD decrease of matricellular proteins and proteoglycans such as periostin and versican. Also, proteins of the complement system and precursors of cardiac peptide hormones were decreased post-LVAD. An increase post-LVAD was evident for individual proteins linked to the innate immune response, proteins involved in diverse metabolic pathways, and proteins involved in protein synthesis. Histological analysis did not reveal significant alterations post-LVAD of deposited collagens or immune infiltration. The proteomic data further highlighted a pronounced inter-patient heterogeneity with regards to the impact of LVAD therapy on the left ventricular myocardial proteome. Finally, the proteomic data showed differential proteolytic processing in response to LVAD therapy.nnnCONCLUSIONSnOur findings underline a strong impact of LVAD therapy on the left ventricular myocardial proteome. Together with previous studies, protein markers of LVAD therapy such as alpha-1-antichymotrypsin are becoming apparent. Further, matricellular proteins are emerging as important components in response to LVAD therapy.