A Comparative Evaluation of SteamVR Tracking and the OptiTrack System for Medical Device Tracking.

Tracking of medical devices can be used in diverse situations, e.g., training as well as image guidance for surgery and surgery planning. Therefore, position and orientation of a device, for instance, an ultrasound probe, need to be identified as precisely as possible. This enables correct representation of digital 3D models in medical image processing platforms such as 3D Slicer or MevisLab. In this manuscript, a comparative evaluation of the low-cost Swept Angle Laser Tracking (SALT) system SteamVR Tracking and the multi-camera-based Opti-Track System is presented. Their potential for medical device tracking is demonstrated in the use case of ultrasound probe tracking for simulation purposes. An evaluation of tracking errors is performed using a Universal Robotics UR5 industrial robot under non-laboratory conditions, involving common issues such as reflections and occlusions. A discussion on the tracking accuracy of both systems is given. The communication of tracking data is established for 3D Slicer and MeVisLab with the use of the PLUS Toolkit via the OpenIGTLink protocol.

Endovascular treatment for nontraumatic rupture of the descending thoracic aorta: long-term results.

BACKGROUND: This study evaluated the long-term results of thoracic endovascular aortic repair (TEVAR) of nontraumatic rupture of the descending thoracic aorta. METHODS: This was a retrospective and observational single-center study. During the 10-year study period, 21 patients (6 males) with an average age of 66.1 ± 12.4 (range 31-81) years underwent emergency TEVAR for nontraumatic rupture of the descending thoracic aorta. The underlying aortic pathologies causing the rupture were degenerative aneurysms in 11 patients, complicated type B dissection in nine, and erosion hemorrhage due to neoplasia in one patient. RESULTS: The 30-day mortality rate was 9.5% (2/21). Two patients died postoperatively: one from a repeat aortic rupture and the other from pneumonia. Two patients underwent early endovascular reintervention. After a median follow-up of 65.6 ± 50.4 (range 1.5-44) months, 10 patients died, resulting in a late mortality of 52.6% (10/19). Six patients (31.5%) developed major complications requiring late reintervention. There was no mortality with reintervention. CONCLUSIONS: Endovascular treatment of the descending thoracic aorta in patients with nontraumatic rupture is a promising treatment option in an emergency setting with a relatively low mortality rate. Despite encouraging early results, TEVAR is associated with a high reintervention rate and poor survival due to nonaortic or procedure-related mortality in the long term.

Secondary interventions after endovascular thoracic aortic repair.

BACKGROUND: Endovascular stent grafting of the descending thoracic aorta has evolved rapidly and is now the standard of care for certain patient subsets. However, the durability of this technique is limited by the development of technique-specific complications at mid-term follow-up. The aim of this study was to evaluate the incidence, techniques, and outcomes of secondary intervention for complications after stent grafting of the descending thoracic aorta. METHODS: Between March 2001 and November 2011, 152 patients underwent endovascular thoracic aortic repair (TEVAR). We identified 19 (12.5%) patients from this cohort who required secondary interventions. RESULTS: The indications for TEVAR were type B aortic dissection in 12 patients, thoracic aortic aneurysm in six patients, and intramural hematoma in one patient. The mean time between TEVAR and secondary intervention was 20.49 ± 24.90 months (range, 1.2-83 months). A secondary endovascular intervention was required in eleven patient, six patients required secondary surgical therapy, and hybrid procedures were performed in two patients. Endoleaks were the most common indication for a secondary intervention. The 30-day mortality rate was 10.5% (2/19). Two perioperative deaths were observed following surgical therapy. During the mean follow-up of 78.06 ± 37.37 months (range, 23-142 months) after TEVAR, four unrelated deaths occurred, two patients were lost to follow-up, and four patients required a further intervention. CONCLUSIONS: Secondary intervention after endovascular stent grafting of the descending thoracic aorta was not infrequently required and can be performed with acceptable risks. However, serial, systematic follow-up is essential to detect late complications and to perform secondary procedures, preferably under elective circumstances.

Perioperative results of the aortic root replacement in strict graft inclusion technique.

BACKGROUND AND AIM: Bleeding may sometimes be a serious problem after the termination of the aortic root replacement. Therefore, the strict graft inclusion technique has been developed to avoid major complications. We present the early results after aortic root replacement in strict graft inclusion technique. MATERIALS AND METHODS: The strict graft inclusion technique was performed in 28 patients between April 2001 and June 2006 in St-Johannes-Hospital-Dortmund, Dortmund, Germany. There were nine female and 19 male patients. The mean age was 57.78 +/- 12.01 years (28 to 77 years). A type A aortic dissection and an ascending aortic aneurysm with aortic valve lesion were the indication to operation in patients. RESULTS: There were no early mortality and postoperative rethoracotomy. The mean postoperative bleeding over mediastinal drains was 565 +/- 310 mL. (100-2250 mL). In exception of the patients with preoperative double thrombocyte aggregation inhibitors therapy and postoperative consumption coagulopathy, the mean postoperative bleeding over mediastinal drain was 443.04 +/- 171.59 mL (100-1100) in the first 24 hours, the transfusion rate was minimal, mean 0.39 +/- 0.64 packed red blood cells (RBC) (0-4) and mean 0.14 +/- 0.27 packed fresh frozen plasma (FFP) (0-4), whereas only in 18 patients (78.26%) out of 23 patients was a transfusion not necessary. The intraoperative and postoperative requirement for substitution of erythrocyte concentrate was mean 1 +/- 1.28 packed RBC (0-5) and FFP concentrate was mean 1.21 +/- 1.90 packed FFP (0-12). CONCLUSIONS: The strict graft inclusion technique for aortic root replacement represents a safe and feasible method to avoid bleeding from coronary ostial anastomoses, from aortic annular suture lines, and annular leak.

Congenital coronary artery fistulas in adults: concomitant pathologies and treatment.

BACKGROUND: Coronary artery fistula is a rare congenital malformation. Complications such as intracardiac shunts, endocarditis, myocardial infarction, aneurysm and sudden death can be observed. The purpose of this article is to present our experience with concomitant cardiac pathologies and discuss various therapeutic approaches including surgical and percutaneous intervention. MATERIALS AND METHODS: During 18,272 diagnostic cardiac catheterizations, coronary artery fistulas were identified incidentally in 10 patients (0.05%). There were 3 female and 7 male patients. The patients' ages ranged from 42 to 76 years. All patients with coronary artery fistula were preoperatively in New York Heart Association functional class and Canadian Cardiovascular Society class II or III. RESULTS: In addition to coronary artery fistula, coronary artery disease was detected in 4 patients (40%), a ventricular septal defect and an aneurysm of the sinuses of Valsalvae with aortic regurgitation in one patient (10%) and an anomalous origin of the LAD from the pulmonary trunk in one patient (10%) during cardiac catheterization. Four (40%) of the total of 10 patients had only coronary artery fistula. Surgical closure of the coronary artery fistula was performed in 7 patients (70%). An interventional fistula closure with a coil device was confirmed by cardiac catheterization in another 3 patients (30%). One patient of the latter group showed a small residual shunt from the LAD to the pulmonary trunk. No death or long-term morbidities could be observed. CONCLUSIONS: Coronary artery fistulas are incidentally diagnosed during coronary artery angiographies in adults and should be closed to prevent complications.

Direct aortic interposition of anomalous left anterior descending coronary artery without cardiopulmonary bypass.

An anomalous origin of the left anterior descending (LAD) coronary artery arising from the pulmonary artery is a congenital malformation rarely described in adults. We describe the case of a 42-year-old man with this malformation who underwent an interposition of the LAD coronary artery to the ascending aorta with an off-pump technique. The clinical presentation, angiographic findings, and surgical treatment are discussed.

Safe hemostasis by application of a new strict graft inclusion technique for replacement of the aortic root.

Bleeding from a coronary anastomosis and aortic annulus is sometimes a problem in the technique for aortic root replacement described by Bentall and DeBono and Cabrol and colleagues. Exposure and repair of these suture lines may be quite difficult after the termination of bypass. This article describes a new technique for aortic root replacement. In our experience to date, 6 patients with aneurysm of the ascending aorta and root and a calcified aortic valve stenosis as well as 1 patient with aortic dissection type A have benefited from this new procedure.