Partial heart transplantation for pediatric heart valve dysfunction: A clinical trial protocol.

Congenital heart defects are the most common type of birth defects in humans and frequently involve heart valve dysfunction. The current treatment for unrepairable heart valves involves valve replacement with an implant, Ross pulmonary autotransplantation, or conventional orthotopic heart transplantation. Although these treatments are appropriate for older children and adults, they do not result in the same efficacy and durability in infants and young children for several reasons. Heart valve implants do not grow with the. Ross pulmonary autotransplants have a high mortality rate in neonates and are not feasible if the pulmonary valve is dysfunctional or absent. Furthermore, orthotopic heart transplants invariably fail from ventricular dysfunction over time. Therefore, the treatment of irreparable heart valves in infants and young children remains an unsolved problem. The objective of this single-arm, prospective study is to offer an alternative solution based on a new type of transplant, which we call "partial heart transplantation." Partial heart transplantation differs from conventional orthotopic heart transplantation because only the part of the heart containing the heart valve is transplanted. Similar to Ross pulmonary autotransplants and conventional orthotopic heart transplants, partial heart transplants contain live cells that should allow it to grow with the recipient child. Therefore, partial heart transplants will require immunosuppression. The risks from immunosuppression can be managed, as seen in conventional orthotopic heart transplant recipients. Stopping immunosuppression will simply turn the growing partial heart transplant into a non-growing homovital homograft. Once this homograft deteriorates, it can be replaced with a durable adult-sized mechanical implant. The protocol for our single-arm trial is described. The ClinicalTrials.gov trial registration number is NCT05372757.

Recent advances in porcine cardiac xenotransplantation: from aortic valve replacement to heart transplantation.

INTRODUCTION: Cardiac xenotransplantation presents significant potential to the field of heart failure by addressing the high demand for donor organs. The availability of xenograft hearts would substantially augment the number of life-saving organs available to patients and may ultimately liberalize eligibility criteria for transplantation. AREAS COVERED: In this review, we will discuss the need for cardiac xenotransplantation and the history of research and clinical practice in this field. Specifically, we address immunologic concepts and clinical lessons learned from heart valve replacement using xenogeneic tissues, the advancement of xenotransplantation using organs from genetically modified animals, and the progression of this research to the first-in-man pig-to-human heart transplantation. EXPERT OPINION: Cardiac xenotransplantation holds tremendous promise, but the indications for this new treatment in adults will need to be clearly defined because mechanical support with ventricular assist devices and total artificial hearts are increasingly successful alternatives in heart failure. Cardiac xenotransplantation will also serve as temporary bridge to allotransplantation in babies with complex congenital heart disease who are too small for the currently available mechanical assist devices and total artificial hearts. Moreover, xenotransplantation of the part of the heart containing a heart valve could deliver growing heart valve implants for babies with severe heart valve dysfunction.

Patterns in Academic Cosmetic Surgery Practice: Population Differences and Procedure Preferences.

PURPOSE: Although growth in cosmetic surgery remains constant in the private setting, academic cosmetic surgery practices are often underdeveloped. Our study aims to determine which patient populations access academic cosmetic surgery services. METHODS: The 2018 Health Care Utilization Project Nationwide Ambulatory Surgery Sample database was used for data analysis. Encounters for the following American Society of Plastic Surgery top 5 procedures for 2020 were selected: blepharoplasty, breast augmentation, liposuction, rhinoplasty, and rhytidectomy. Patient encounter data were collected because it relates to median income, geographic location, and primary payer status. RESULTS: The 2018 Nationwide Ambulatory Surgery Sample data set contained 44,078 encounters at academic surgical centers for the procedures listed previously. Low-income patients account for 13.7% of academic cosmetic surgery encounters compared with 37.9% for high-income patients. Breast augmentation rates are higher among low-income patients (20.5% vs 17.2%, P < 0.001), and high-income patients undergo rhytidectomy more frequently (5.7% vs 3.0%, P < 0.001). In the academic setting, patients from large metropolitan areas encompass the majority of cosmetic encounters (71.0%), and these patients are more likely to proceed with rhinoplasty, rhytidectomy, and liposuction procedures (P < 0.001). Patients from smaller metropolitan areas undergo blepharoplasty more frequently compared with those from larger metropolitan areas (56.4% vs 41.8%, P < 0.001). Self-pay and privately insured patients comprise the majority of academic cosmetic surgery encounters (40.8% and 29.9%, respectively). Eighty-eight percent of Medicare patients within this cohort underwent blepharoplasty, whereas self-pay patients accessed breast augmentation, liposuction, and rhytidectomy more often than other insured patients. CONCLUSIONS: Income status, patient location, and primary payer status play an important role in academic cosmetic surgery access rates and procedure preferences. Academic cosmetic practices can use these insights to tailor their services to the populations they serve.

Physiological Ventricular Simulator for Valve Surgery Training.

Surgical simulation is becoming increasingly important in training cardiac surgeons. However, there are currently no training simulators capable of testing the quality of simulated heart valve procedures under dynamic physiologic conditions. Here we describe a dynamic ventricular simulator, consisting of a 3D printed valve suspension chamber and a model 1423 Harvard apparatus pulsatile pump, which can provide close to physiologic hemodynamic perfusion of porcine aortic roots attached to the valve chamber for education and training in cardiac surgery. The simulator was validated by using it to test aortic valve leaflet repairs (n = 6) and aortic valve replacements (n = 3) that were performed by two trainees. Procedural success could be evaluated by direct visualization of the opening and closing valve, hemodynamic measurements and echocardiography. We conclude that, unlike other methods of simulation, this novel ventricular simulator is able to test the functional efficacy of aortic procedures under dynamic physiologic conditions using clinically relevant echocardiographic and hemodynamic outcomes. While validated for valve surgery, other potential applications include ascending aortic interventions, coronary re-implantation or catheter-based valve replacements.