A light-reflecting balloon catheter for atraumatic tissue defect repair

Nell’uomo, la presenza di un difetto (soluzione di continuità a carico di qualsiasi tessuto biologico richiede la chiusura chirurgica dello stesso, spesso in condizioni di emergenza, che si basa per lo più sull’utilizzo di componenti sintetiche e/o metalliche, a loro volta responsabili di fenomeni infiammatori a causa della loro scarsa biocompatibilità. L’utilizzo di collanti biodegradabili e attivabili, rappresenta un’alternativa appetibile ai comuni metodi di sutura, ma la mancanza di un dispositivo, appositamente disegnato, ed in grado di rilasciare in maniera appropriata ed efficace il collante, senza risultare traumatico per il tessuto, nè limita la traslazione clinica. Il nostro team di ricerca ha sviluppato un dispositivo per la chiusura di difetti tissutali, multifunzionale, la cui tecnologia, basata su cateteri, non prevede l’impianto permanente di componenti sintetiche e/o metalliche e funziona mediante a) dispiegamento di un patch elastico e biocompatibile rivestito da collante foto-attivabile; b) dal rilascio di un doppio pallone necessario alla stabilizzazione del tessuto durante procedura e ad applicare il giusto grado di pressione sul patch; c) da un sistema di fibre ottiche per l’emanazione di luce ultravioletta e d) un rivestimento di alluminio per una uniforme dispersione della luce indispensabile per l’attivazione del collante. l dispositivo è stato valutato come strumento per la chiusura in vivo di difetti cardiaci nel modello animale di piccola taglia (ratto) e come strumento per la chiusura perventricolare di difetti settali nell’animale di grossa taglia (maiale). Nel modello suino, il patch si è dimostrato adeso e resistente al passaggio tangenziale del flusso sanguigno ad alta pressione, riducendo acutamente le dimensioni del difetto a <1.6 mm (non emodinamicamente significativo). Questa nuova piattaforma ha il potenziale di garantire la riparazione atraumatica e mini-invasiva dei difetti tissutali nei pazienti di ogni età, anche se tecnicamente difficili da raggiungere.A congenital or iatrogenic tissue defect often requires closure by open surgery or metallic components that can erode tissue. Biodegradable, hydrophobic light-activated adhesives represent an attractive alternative to sutures, but lack a specifically designed minimally invasive delivery tool, which limits their clinical translation. We developed a multifunctional, catheter-based technology with no implantable rigid components that functions by unfolding an adhesive-loaded elastic patch and deploying a double-balloon design to stabilize and apply pressure to the patch against the tissue defect site. The device uses a fiber-optic system and reflective metallic coating to uniformly disperse ultraviolet light for adhesive activation. Using this device, we demonstrate closure on the distal side of a defect in porcine abdominal wall, stomach, and heart tissue ex vivo. The catheter was further evaluated as a potential tool for tissue closure in vivo in rat heart and abdomen and as a perventricular tool for closure of a challenging cardiac septal defect in a large animal (porcine) model. Patches attached to the heart and abdominal wall with the device showed similar inflammatory response as sutures, with 100% small animal survival, indicating safety. In the large animal model, a ventricular septal defect in a beating heart was reduced to <1.6 mm. This new therapeutic platform has utility in a range of clinical scenarios that warrant minimally invasive and atraumatic repair of hard-to-reach defects

Nonischemic Donor Heart Preservation: New Milestone in Heart Transplantation History

Heart transplantation is considered the gold standard for the treatment of advanced end-stage heart failure. However, standard donors after brain death are decreasing, whereas patients on the heart transplant waitlist are constantly rising. The introduction of the ex vivo machine perfusion device has been a turning point; in fact, these systems are able to significantly reduce ischemic times and have a potential effect on ischemia-related damage reduction. From a clinical standpoint, these machines show emerging results in terms of heart donor pool expansion, making marginal donors and donor grafts after circulatory death suitable for donation. This article aims to review mechanisms and preclinical and clinical outcomes of currently available ex vivo perfusion systems, and to explore the future fields of application of these technologies

A step-by-step problem-solving strategy in a patient with heart failure and cerebral aneurysm

Left ventricular assist devices (LVAD) implantation is an established treatment for patients with end-stage heart failure. HeartMate 3 (HM3) is a continuous-flow centrifugal pump, recently introduced in the clinic, which has shown greater hemocompatibility compared to similar devices of previous generations. Nevertheless, anticoagulation is still required after HM3 implant to avoid pump dysfunction. Hereafter, we describe the case of a patient candidate to LVAD implantation for end-stage heart failure presenting a concomitant cerebrovascular lesion, accidentally found during pre-operative assessment, which would have contraindicated the procedure (for the prohibitive risk of cerebral hemorrhage), unless a step by step problem-solving approach was adopted

Successful surgical management of ventricular fibromas in children

Objectives A uniform management strategy has not been established for the treatment of large ventricular fibromas identified in children. The goal of the present study was to review our experience with surgical resection of this uncommon tumor. Methods We performed a retrospective review of all patients with a diagnosis of ventricular fibromas who had undergone surgical intervention at our institution from July 1990 to June 2013. The clinical records and pathology reports were reviewed and available follow-up data obtained. Results A total of 20 patients had a ventricular fibroma. The median age at presentation was 4 years (range, 5 months to 12 years). Of these, 18 (89%) presented with ventricular tachycardia (n = 15) or frequent ectopy (n = 3), and 1 (6%) with outflow tract obstruction; 1 (6%) was asymptomatic and diagnosed during routine evaluation for a murmur. One patient had undergone previous ablation, and one had had an automated internal cardiac defibrillator implanted for ventricular tachycardia control. Before tumor resection at our institution, 1 patient had been listed for transplantation at an outside institution and 1 had undergone previous extracardiac Fontan without tumor resection. All patients underwent successful tumor excision with no recurrence of ventricular arrhythmia during a median follow-up period of 3.3 years (range, 1 month to 14.7 years). One patient underwent planned staged tumor resection. No patient died. Conclusions Primary ventricular fibromas, even when very large, can be managed by surgical resection, with excellent short- and intermediate-term ventricular function and relief of arrhythmic events

Preliminary Computational Analysis of Three Configurations for an Innovative Ventricular Chamber

(1) Background: shape, dimension, hemodynamics, and hemocompatibility are just a few of the several challenging key points that must be addressed in designing any suitable solution for the ventricular chamber of mechanical circulatory support devices. A preliminary evaluation of different geometries of bellow\u2010like ventricular chambers is herein proposed. The chambers were made with a polycarbonate urethane that is acknowledged to be a hemocompatible polymer. (2) Methods: an explicit dynamic computational analysis was performed. The actuation of the three chambers was simulated without the presence of an internal fluid. Maximum stress and strain values were identified, as well as the most critical regions. Geometric changes were checked during simulated motion to verify that the dimensional constraints were satisfied. (3) Results: one chamber appeared to be the best solution compared to the others, since its dimensional variations were negligible, and effective stresses and strains did not reach critical values. (4) Conclusions: the identification of the best geometric solution will allow proceeding with further experimental studies. Fluid\u2013structure interactions and fatigue analyses were investigated

The Role of Transoesophageal Echocardiography in High Risk Patients Undergoing Cardiovascular Surgery

Introduction The aim of this study is to examine the role of transoesophageal echocardiography (TOE) in the evaluation and management of high risk patients undergoing cardiac-vascular surgery. Methods From March 2009 to September 2012, 2344 patients underwent cardiac surgery at the Prince Sultan Cardiac Center. Out of them, 835 were high-risk patients (Euroscore >=6). TOE was performed on 465 pts (group A) while in 370 pts (group B) only preoperative TTE was performed. There were no differences in surgical procedure between the 2 groups. In group A, left and right ventricular functions were assessed by bidimensional (left ventricular ejection fraction) and M-MODE (tricuspid anular plan systolic excursion, TAPSE) TOE. Primary end-points analysed were low output syndrome (LOS), acute renal failure (ARF), acute respiratory failure (ARespF), ICU stay, hospital stay and intraoperative mortality. Results We observed low incidence statistically significant for all the end-points in group A vs group B (LOS: 8.0% vs 16.5%, p<.05; IRA: 2.5% vs 18.5%, p<.05; ArespF: 4% vs 14%, p<.05; ICU stay: 2.0 days vs 6.0 days, p<.05; hospital stay: 8 days vs 18 days, p<.05; intraoperative mortality: 4% vs 10%, p<.05). Conclusion Intraoperative TOE evaluation is associated with better clinical outcomes. It seems related to more appropriate management of fluid administration, inotropic use and dosage, operative time reduction. All this factors led to reduce incidence of morbidity, mortality, ICU and Hospital stay. This results strongly support the routinely use of TOE in high risk patients who undergo cardiovascular surgery, and also anticipate that good results are likely to be obtained in the management of endovascular procedures