50 research outputs found
Stereo-Based Endoscopic Tracking of Cardiac Surface Deformation
Abstract. We propose an image-based motion tracking algorithm that can be used with stereo endoscopic and microscope systems. The tracking problem is considered to be a time-varying optimization of a parametric function describing the disparity map. This algorithm could be used as part of a virtual stabilization system that can be employed to compensate residual motion of the heart during robot-assisted off-pump coronary artery bypass surgery (CABG). To test the appropriateness of our methods for this application, we processed an image sequence of a beating pig heart obtained by the stereo endoscope used in the da Vinci robotic surgery system. The tracking algorithm was able to detect the beating of the heart itself as well as the respiration of the lungs.
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Should Status II Patients Be Removed From the Pediatric Heart Transplant Waiting List? A Multi-institutional Study
The survival benefit of cardiac transplantation (CTx) among Status 2 (stable outpatient) adult recipients has been questioned, but few studies have addressed this issue in pediatric patients. This study examined the following hypothesis: “Status 2 pediatric recipients have a survival benefit with CTx.”
Between 1993 and 2003, 2,375 patients were listed for CTx at 24 institutions; 614 (26%) of these patients were Status 2. By multivariate competing outcomes hazard function analysis, death after listing and post-transplant survival were analyzed.
A single-phase hazard function described the risk of death after listing, with 20% actual mortality within 2 months after Status 1 listing. The “natural history” of Status 2–listed patients was estimated by the risk of death, whereas waiting and risk of deterioration to Status 1 at CTx (weighted by the probability of death at 3 months after Status 1 listing). At 4 months after CTx, survival with CTx exceeded the predicted “natural Hx” survival in all diagnostic categories out to 4 years of follow-up.
Pediatric patients currently listed as Status 2 have a survival benefit with transplant out to at least 4 years. A pediatric allocation system restricted to Status 1 patients could only be justified if the vast majority of such patients could be transplanted within 1 to 2 months
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392: Infection and Rejection Risk Using Induction with Interleukin II Receptor Blockers vs. Antithymocyte Globulin vs. No Induction: A Multi-Institutional Study
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Long-Term Survivors Following Pediatric Heart Transplantation: A PHTS Database Analysis
Short-term outcomes following pediatric heart transplantation have improved over time with 1-year survival of over 90%, but comparable improvements in longer-term survival continues to have important barriers. We sought to investigate long-term outcomes following pediatric heart transplantation and to identify favorable factors associated with long-term survival.
The Pediatric Heart Transplant Society (PHTS) database was queried for pediatric heart transplant recipients from 1993-2010. Patients with graft survival ≥10 years were compared to the general cohort and to patients with follow up ≥3 but <10 years. Kaplan-Meier analysis was used to evaluate overall survival and 3-year conditional survival. Factors associated with graft loss after 3-year conditional survival were identified using Cox proportional hazard modeling.
3,436 patients were transplanted between 1993-2010, of whom 1355 (39.4%) had ≥10 years of follow up (median 13.7 years (range 10.0-27.5)). Of those surviving to 10 years post-transplant, 84.4% and 74.3% survived to 15 and 20 years, respectively. Of the complete PHTS cohort, overall survival at 15 years was 53.3%. Patients <1 year at transplant who survived to 10 years had improved survival compared to other age groups (Figure). In 10-year survivors, the leading cause of subsequent mortality was cardiac allograft vasculopathy (CAV). Risk factors for graft loss after 3 years post-transplant were age, female gender, African American race, use of steroids at 2 years, rejection (particularly with hemodynamic compromise) and CAV (p-value for all <0.05). Use of mTORi was not associated with long-term survival.
Heart transplantation remains an effective therapy in pediatric patients with a growing number of long-term survivors. Of modifiable risk factors, cessation of steroids may provide long-term survival benefit. Additional studies on social determinants of health are warranted to address increased mortality among African Americans