Epicardial Transplantation of Autologous Cardiac Micrografts During Coronary Artery Bypass Surgery

Systematic review and meta-analysis of the use of micrografting technology in humans

AimTo critically assess the evidence on micrografting technology to evaluate its effectiveness when used alone or as an adjunct to regenerative treatment in various medical and dental applications.MethodsSeven electronic databases, including Cochrane Central Register of Controlled Trials (CENTRAL), Medline Ovid, Embase Ovid, Cumulative Index to Nursing and Allied Health Literature EBSCOhost, Web of Science Core Collection, System for Information on Grey Literature in Europe, and Bielefeld Academic Search Engine, were searched until 15 July 2024. Risk of bias assessment and qualitative and quantitative (random-effect models) analyses were conducted.ResultsA total of 55 studies were identified. Most studies (n = 24) reported on burns, followed by 10 studies on ulcers/wounds, 7 on androgenetic alopecia, 3 on vitiligo, 3 on cartilage and bone defects, and 1 on coronary artery bypass graft surgery. Dental applications included sinus lift (three studies), socket preservation (two studies), and intrabody defects (two studies). A meta-analysis of four studies on the management of burns confirmed that micrografting led to reduced healing periods compared with other grafting techniques (weighted mean difference: -0.98, 95% confidence interval: -1.84 to -0.12, p = 0.03), with a high level of heterogeneity (83.57%) and risk of bias.ConclusionMicrografting technology may lead to shorter healing time and improved patient morbidity.

State of the Art in Left Atrial Appendage Occlusion

Left atrial appendage occlusion (LAAO) has become an important therapeutic target for stroke prevention in patients with nonvalvular atrial fibrillation. Over the past 2 decades, several advancements in LAAO devices (percutaneous and surgical) have been made for stroke prevention and arrhythmia therapy. However, there are several unanswered questions regarding optimal patient selection, the preferred LAAO approach and device, the management of periprocedural and postprocedural complications, including pericardial effusion, device-related thrombus, and device leaks. This review focuses on fundamental foundational concepts in various aspects of the left atrial appendage and management strategies as they relate to current clinical needs.

Efficacy of autologous micrografts technology: a promising approach for chronic wound healing and tissue regeneration-a pilot study

Introduction

This study explores the efficacy of Autologous Micrografts Technology (AMG) in treating chronic wounds refractory to traditional therapies.

Methods

AMGs, derived from adipose tissue or dermis using a mechanical fragmentation process, were applied to patients with post-surgical dehiscence. A comprehensive evaluation of wound healing outcomes, including surface area reduction and complete healing, was conducted over a 90-day follow-up period. Additionally, the study investigated the cellular antioxidant activity of AMG solutions and characterized the exosomes obtained through mechanical disaggregation.

Results

Results indicate significant improvements (p < 0.05) in wound healing, with 91.66% of patients showing at least a 50% reduction in lesion size and 75% achieving complete healing by day 90. Notably, AMG technology demonstrated immediate efficacy with fat-only application, while combined dermis and fat micrografts showed longer-term benefits, particularly in chronic wounds. The study also elucidated the mechanism of action of AMGs, highlighting their role in enhancing cellular antioxidant activity and exosome-mediated tissue regeneration.

Discussion

Overall, these findings underscore the promising potential of AMG technology as a versatile and effective treatment option for chronic wounds, warranting further investigation into its mechanisms and clinical applications.

Cell sheet transplantation for ischemic heart disease: a systematic review

OBJECTIVE

Cell sheet transplantation is emerging as an appealing alternative for ischemic heart disease patients as it potentially can increase stem cell viability and retention. But the outcomes and safety of this treatment are still limited in literature and the result varies widely. We conduct a systematic review to look at the efficacy and safety of this promising transplantation method.

METHODS

A systematic review was performed according to PRISMA guidelines. A comprehensive literature search was undertaken using the PubMed, Scopus, and Embase databases. Articles were thoroughly evaluated and analyzed.

RESULTS

Seven publications about cell sheet transplantation for ischemic heart disease patients were included. The primary outcomes measured were left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) class. Safety measurement was depicted by cardiac-related readmission and deaths. The follow-up time ranged from 3 to 36 months for clinical outcomes and 8.5 years for safety outcomes. Cell sheet transplantation showed improvement in LVEF and NYHA class in most studies. Cardiac-related readmission and adverse events of cell sheet transplantation range from 0 to 30.4%, all were nonfatal as no cardiac-related death was reported. Patient preoperative status seems can affect the patient's response to cell sheet therapy.

CONCLUSION

Cell sheet transplantation can safely improve LVEF and NYHA class in ischemic heart disease patients, even in very low ejection fraction patients with unsuccessful standard therapy before. Further studies with better patient inclusion, larger population, and long-term follow-up required to confirm these results.

Nonthrombogenic Roles of the Left Atrial Appendage: JACC Review Topic of the Week

The atrial appendage (LAA) is a well-established source of cardioembolism in patients with atrial fibrillation. Therefore, research involving the LAA has largely focused on its thrombogenic attribute and the utility of its exclusion in stroke prevention. However, recent studies have highlighted several novel functions of the LAA that may have important therapeutic implications. In this paper, we provide a concise overview of the LAA anatomy and summarize the emerging data on its nonthrombogenic roles.

Use of left atrial appendage as an autologous tissue source for epicardial micrograft transplantation during LVAD implantation

We report here the first clinical use of the left atrial appendage (LAA) for epicardial micrograft transplantation during left ventricular assist device (LVAD) implantation. Previously, a sample from the right atrial appendage (RAA) has been available for processing and administering micrograft therapy in cardiac surgery. Both LAA and RAA are rich sources of various types of myocardial cells and are capable of providing both paracrine and cellular support to the failing myocardium. The surgical approach of LAA micrografting facilitates epicardial micrograft therapy dose escalation and treatment of larger myocardial areas than done previously. Moreover, as collection of treated vs. untreated tissues from the recipient heart is possible following LVAD implantation at the time of heart transplantation, the evaluation of the therapy's mechanism of action can be further deciphered at cellular and molecular levels. This LAA modification of the epicardial micrografting technique has the overall potential to facilitate the adoption of cardiac cell therapy during heart surgery.

Structural and Functional Support by Left Atrial Appendage Transplant to the Left Ventricle after a Myocardial Infarction

The left atrial appendage (LAA) of the adult heart has been shown to contain cardiac and myeloid progenitor cells. The resident myeloid progenitor population expresses an array of pro-regenerative paracrine factors. Cardiac constructs have been shown to inhibit deleterious remodeling of the heart using physical support. Due to these aspects, LAA holds promise as a regenerative transplant. LAAs from adult mT/mG mice were transplanted to the recipient 129X1-SvJ mice simultaneously as myocardial infarction (MI) was performed. A decellularized LAA patch was implanted in the control group. Two weeks after MI, the LAA patch had integrated to the ventricular wall, and migrated cells were seen in the MI area. The cells had two main phenotypes: small F4/80+ cells and large troponin C+ cells. After follow-up at 8 weeks, the LAA patch remained viable, and the functional status of the heart improved. Cardiac echo demonstrated that, after 6 weeks, the mice in the LAA-patch-treated group showed an increasing and statistically significant improvement in cardiac performance when compared to the MI and MI + decellularized patch controls. Physical patch-support (LAA and decellularized LAA patch) had an equal effect on the inhibition of deleterious remodeling, but only the LAA patch inhibited the hypertrophic response. Our study demonstrates that the LAA transplantation has the potential for use as a treatment for myocardial infarction. This method can putatively combine cell therapy (regenerative effect) and physical support (inhibition of deleterious remodeling).