Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery最新文献

Objective: An optimal valve replacement prosthesis demands durable leaflet technology, superior hemodynamic performance, and ease of use. Preclinical evaluation of polymer leaflets has historically demonstrated mechanical failure related to biodegradation. We present the preclinical evaluation of the novel TRIA™ polymer valve (Foldax, Salt Lake City, UT, USA) and a case report of TRIA mitral valve replacement.

Methods: A uniquely formulated, biostable, and biocompatible polymer (LifePolymer™ [LP], Foldax) has been designed to meet the functional demands of cardiac hemodynamics. Preclinical in vitro evaluation included biocompatibility testing, thrombogenicity testing, and toxicologic assessment followed by evaluation in the arteriovenous shunt of nonhuman primates and in the aortic position in sheep. Clinical evaluation of early human aortic and mitral implantation included computed tomography imaging and echocardiographic examination.

Results: In vitro studies of LP demonstrated no evidence of toxicity or tissue injury, no cytological injury in cell culture, and no intracutaneous sensitization. LP proved to be nonhemolytic by direct and extract methods, and complement activation was insignificant. Genotoxicity analysis proved LP to be nonmutagenic. All standard toxicologic assessments were within the margin of safety. Biostability was confirmed without polymer degradation or excessive comparative thrombogenicity. Ovine 6-month aortic valve explantation showed no leaflet calcification and minimal fibrinous depositions. An early human case example shows no evidence of leaflet thrombus formation at 6 months and a mean mitral gradient of 3 mm Hg at 12 months.

Conclusions: LP has met the requirements for a prosthetic polymer human heart valve. The surgical TRIA Mitral Valve has demonstrated promising early human clinical success, potentially facilitating a lifetime valve replacement strategy.

Objective: Pediatric mitral valve replacement remains a significant challenge due to the lack of growth-capable prostheses, often necessitating multiple reoperations. Partial heart transplantation (PHT) has shown promise in the semilunar position but has not been studied in the atrioventricular (AV) position. This study evaluates the feasibility and growth potential of AV PHT in an in vivo porcine model.

Methods: Three Yorkshire piglets underwent AV PHT, with the donor mitral valve implanted into the tricuspid position due to animal intraoperative tolerance limitations. The first 2 animals were used to refine surgical technique. The third piglet was designated for 2-month survival with serial echocardiographic monitoring. Donor valves were procured on the day of surgery to minimize ischemic time. Postoperative immunosuppression included tacrolimus, mycophenolate mofetil, and methylprednisolone.

Results: The survival animal tolerated the procedure well and remained clinically stable. Echocardiography demonstrated significant growth of the PHT mitral annulus from 2.0 cm to 4.3 cm, compared with 2.4 cm to 3.0 cm in the native annulus. The length of the PHT leaflet increased from 1.3 cm to 2.4 cm, whereas the length of the native leaflet increased from 1.1 cm to 1.9 cm. Nonprogressive moderate regurgitation was observed without stenosis. Gross examination confirmed excellent tissue integration without calcification or fibrosis.

Conclusions: This study demonstrates the in vivo feasibility and growth potential of AV PHT, representing a promising step toward growth-capable valve replacement for pediatric patients with irreparable mitral valve disease.

Despite efforts to improve donor heart allocation policies, geographic disparities, logistical challenges and patient criteria limit organ availability. However, recent surgical innovations offer potential solutions. These include partial heart transplantation and xenotransplantation. Partial heart transplantation is a new procedure with the potential to address several clinical challenges in treating congenital heart defects. Cardiac xenotransplantation involves the transplantation of genetically modified porcine hearts into humans, offering a potential solution to the shortage of donor organs. Although immunologic barriers and ethical concerns remain, ongoing research aims to mitigate the risks and optimize outcomes, providing hope for patients in need. These innovative surgical approaches offer promising avenues for addressing the critical shortage of donor hearts and with ongoing research, may hold the potential to revolutionize heart transplantation, and improve outcomes for patients facing terminal heart failure.

Objective: To assess the midterm outcomes and feasibility of using 3-dimensional total endoscopic surgery (3D TES) for complete correction of partial atrioventricular septal defect (PAVSD) in children.

Methods: A descriptive study from January 2018 to June 2024 involved 20 patients with PAVSD who underwent surgical repair using 3D TES. The average patient age and average weight were 9.1 (range: 4 to 15) years and 25.02 kg, respectively. Mitral valve regurgitation was classified as mild in 2 patients, moderate in 12, and severe in 6, whereas tricuspid valve regurgitation was mild in 13 patients and moderate in 7.

Results: Peripheral circulation was established in all patients. Cardiopulmonary bypass and aortic cross-clamp times were 86.2 min and 142.2 min, respectively. The mechanical ventilation time averaged 4.9 h. Postoperative echocardiography included complete closure of the atrial septal defect, with mild mitral valve regurgitation in 16 patients and no regurgitation in 4. Tricuspid valve regurgitation was mild in 11 patients, and 9 patients had no regurgitation. During an average postoperative follow-up period of 3.35 years, there were no mortalities or cases requiring reoperation.

Conclusions: The 3D TES demonstrates feasibility, safety, and efficacy in treating PAVSD in children, with apparent aesthetic advantages.

Objective: The aim of the current study was to analyze the clinical and surgical outcomes of patients undergoing isolated tricuspid valve surgery (ITVS) from the available literature. It currently remains uncertain whether arrested heart (AH) surgery has superior postoperative outcomes over beating heart (BH) for ITVS.

Methods: A systematic review and meta-analysis were conducted by searching PubMed, ScienceDirect, Scopus, DOAJ, SciELO, and Cochrane databases from 2000 until November 2024. The protocol was registered with the International Prospective Register of Systematic Reviews under the PROSPERO registration number CRD42024622618.

Results: A total of 22 studies met the inclusion criteria. These studies were published between 2012 and 2023 and included a combined total of 1,627 patients, with 1,053 in the BH group and 574 in the AH group. The present analysis showed that patients undergoing BH surgery were generally more comorbid and more frequently underwent minimally invasive procedures as compared with patients undergoing AH surgery. The BH and AH groups reported no significant differences in postoperative outcomes. At follow-up, BH was associated with higher recurrent >2+ tricuspid regurgitation rates (P = 0.048), but this did not affect late survival (hazard ratio [HR] = 0.90, 95% confidence interval [CI]: 0.68 to 1.19, P = 0.457) or reintervention for TV (HR = 1.18, 95% CI: 0.61 to 2.29, P = 0.622) rates.

Conclusions: A consensus between BH and AH for ITVS is still lacking. However, BH ITVS procedures appear to be the preferred surgeon choice for higher-risk patients. At follow-up, the BH group showed higher rates of recurrent tricuspid regurgitation >2+, without affecting late survival or rates of TV reintervention.