Katherine M. Marsh

Robotic Left Ventricular Assist Device Implantation Using Left Thoracotomy Approach in Patients with Previous Sternotomies.

Left ventricular assist devices (LVADs) are commonly used as either a bridge-to-transplant or a destination therapy. The traditional approach for LVAD implantation is via median sternotomy, but many candidates for this procedure have a history of failed cardiac surgeries and previous sternotomy. Redo sternotomy increases the risk of heart surgery, particularly in the setting of advanced heart failure. Robotics facilitates a less invasive approach to LVAD implantation that circumvents some of the morbidity associated with a redo sternotomy. We compared the outcomes of all patients at our institution who underwent LVAD implantation via either a traditional sternotomy or using robotic assistance. The robotic cohort showed reduced resource utilization including length of hospital stay and use of blood products. As the appropriate candidates become elucidated, robotic assistance may improve the safety and cost-effectiveness of reoperative LVAD surgery.

Robotic-assisted implantation of ventricular assist device after sternectomy and pectoralis muscle flap.

Left ventricular assist devices are increasingly important in the management of advanced heart failure. Most patients who benefit from these devices have had some prior cardiac surgery, making implantation of higher risk. This is especially true in patients who have had prior pectoralis flap reconstruction after sternectomy for mediastinitis. We outline the course of such a patient, in whom the use of robotic assistance allowed for a less invasive device implantation approach with preservation of the flap for transplantation.

First in Man: Sternal Reconstruction with Autologous Stem Cells.

Sternal nonunion is associated with high morbidity and treated using rigid plate and screw fixation. This is the first reported example of successful sternal reconstruction using adipose-derived stromal vascular fraction (SVF) stem cells in addition to traditional techniques. Mesenchymal stem cells, one component of the SVF, play an important role in bone healing and were therefore used to promote remedial processes in a patient with sternal nonunion. A 3D printed model of the patients sternum was used for preoperative planning of the plating. Intraoperatively, SVF was isolated using ultrasonic cavitation and previously planned sternal plating was completed. A total of 300 million cells were delivered via both local injection and intravenously before chest closure. The patients pain dramatically decreased, commensurate with healed areas of nonunion by 3 months and maintained at 6 months postoperatively, supported by three-dimensional computed tomography imaging. Utilizing autologous stem cells from the SVF in conjunction with existing plating techniques may provide an optimal platform to stabilize the sternum and promote bone healing, although additional study is recommended.

Metabolic Impact of Rapamycin (Sirolimus) and B-Estradiol Using Mouse Embryonic Fibroblasts as a Model for Lymphangioleiomyomatosis

IntroductionLymphangioleiomyomatosis (LAM) is a rare, progressive cystic lung disease that predominantly affects women of childbearing age. Exogenous rapamycin (sirolimus) has been shown to improve clinical outcomes and was recently approved to treat LAM, whereas estrogen (E2) is implicated in disease progression. No consistent metabolic model currently exists for LAM, therefore wild-type mouse embryonic fibroblasts (MEF +/+) and TSC2 knockout cells (MEF −/−) were used in this study as a model for LAM.MethodsOxygen consumption rates (OCR) and redox potential were measured to determine metabolic state across control cells, MEF +/+ and −/− cells treated with rapamycin (Rapa), and MEF +/+ and −/− cells treated with E2. An XF96 extracellular flux analyzer from Seahorse Bioscience® was used to measure OCR, and a RedoxSYS™ ORP was used to measure redox potential.ResultsOCR of MEF −/− cells treated with rapamycin (MEF −/− Rapa) versus MEF −/− control were significantly lower across all conditions. The static oxidation reduction potential of the MEF −/− Rapa group was also lower, approaching significance. The coupling efficiency and ratio of ATP-linked respiration to maximum respiration were statistically lower in MEF −/− Rapa compared to MEF +/+ Rapa. There were no significant metabolic findings across any of the MEF cells treated with E2. MEF −/− control cells versus MEF +/+ control cells were not found to significantly differ.ConclusionMEF cells are thought to be a feasible metabolic model for LAM, which has implications for future pharmacologic and biologic testing.

Wound Measurement, Score

Wound measurement is a helpful quantitative finding in wound assessment that can be used as a practical approach to track wound healing. The most common techniques for wound measurement include manual metric measurement, mathematical models, manual planimetry, digital planimetry, stereophotogrammetry, and digital imaging methods. An ideal wound measurement technique has high accuracy, reliability, and feasibility. Currently, no gold standard method exists for wound measurement, though digital methods are preferred since they are generally more accurate and precise than manual methods. With advancements in technology, newer wound measurement techniques are increasingly being developed and studied.

Anti-inflammatory properties of amniotic membrane patch following pericardiectomy for constrictive pericarditis

BackgroundSince constrictive pericarditis is most often idiopathic and the pathophysiology remains largely unknown, both the diagnosis and the treatment can be challenging. However, by definition, inflammatory processes are central to this disease process. Amniotic membrane patches have been shown to possess anti-inflammatory properties and are believed to be immune privileged. Due to these properties, amniotic membrane patches were applied intraoperatively in a complicated patient presenting with constrictive pericarditis.Case presentationA patient with a history of multiple cardiac surgeries presented with marked fatigue, worsening dyspnea and sinus tachycardia. He was found to have constrictive physiology during cardiac catheterization, with cardiac MRI demonstrating hepatic vein dilatation, atrial enlargement and ventricular narrowing. After amniotic membrane patch treatment and pericardiectomy, post-operative cardiac MRI failed to demonstrate any appreciable pericardial effusion or inflammation, with no increased T2 signal that would suggest edema.ConclusionsGiven the positive results seen in this complex patient, we suggest continued research into the beneficial properties of amniotic membrane patches in cardiac surgery.