Longer Support Time Research Articles

Characterization of injuries and dressings of left ventricular assist device drivelines

Aim: To Identify and characterize driveline-related injuries among patients with HeartMate II® or HeartMate 3® and assess the dressings used during hospital stay. Method: Observational, cross-sectional study conducted between 2015 and 2023 at a large hospital in São Paulo, Brazil. Results: The sample consisted of 18 patients, with driveline injuries identified in 66.7%, categorized into stages one (83.3%), two (8.3%), and four (8.3%). Of these, 66.6% were diagnosed with driveline infection according to the Utah classification: stages two (50%), three (37.5%), and four (12.5%). A correlation was found between the occurrence of injuries and longer support time (p=0.035) and the presence of a diagnosis of driveline infections (p=0.013). The solutions most frequently used were Chloraprep™ (27.8%), Aqueous Chlorhexidine 0.5% (22.2%), and Saline 0.9% (22.2%), while the dressings were IV3000™ (72.2 %), Excilon™ (44.4%), and Biatain®Ag (33.3%). Conclusion: Driveline dressings are not standardized, indicating the need for new protocols and guidelines based on studies of high methodological quality and presenting robust evidence of the best solutions and dressings to prevent complications and promote better outcomes.

Role of Echocardiography in the Management of Patients with Advanced (Stage D) Heart Failure Related to Nonischemic Cardiomyopathy.

Echocardiography (ECHO) is indispensable for evaluation of patients with terminal chronic heart failure (HF) who require transplantation or mechanical circulatory support by a left- or biventricular assist device (LVAD or BiVAD, respectively). In LVAD candidates, ECHO represents the first-line investigation necessary for a timely discovery of heart-related risk factors for potentially life-threatening post-operative adverse events, including identification of patients who necessitate a biventricular support. ECHO is also required for intra-operative guiding of VAD implantation and finding of the most appropriate setting of the device for an optimal ventricular unloading, postoperative surveillance of the VAD support, and monitoring of the RV changes in LVAD recipients. Thanks to the ECHO, which has decisively contributed to the proof that prolonged VAD support can facilitate cardiac reverse remodeling and functional improvement to levels which allow successful weaning of carefully selected patients from LVAD or BiVAD, the previous opinion that chronic non-ischemic cardiomyopathy (NICMP) is irreversible could be refuted. In patients with normalized and stable right heart catheter-derived hemodynamic parameters obtained at short-term interruptions of VAD support, ECHO has proved able to predict post-weaning long-term freedom from HF recurrence in patients with pre-implant terminal chronic NICMP. The purpose of this article is to offer an actualized theoretical and practical support for clinicians engaged in this particularly challenging and topical issue especially due to the new practical aspects which have emerged in conjunction with the growing use of long-term ventricular assist devices as bridge-to-transplantation or as destination therapy, as well as the increasing evidence that, in some patients, such VAD can become a bridge-to-recovery, allowing the removal of the device after a longer support time.

A Closed-Circuit Ex Vivo Perfusion System for Pediatric Solid Organ Transplantation

<h3>Purpose</h3> Donation after cardiac death and ex-vivo organ perfusion are increasingly used strategies to mitigate donor organ shortage in cardiac transplantation. These concepts have mainly been established in adults, while neglecting the specific needs for application in children. To address this gap, we have developed an adjustable closed-circuit ex-vivo perfusion system that reduces priming volume, accommodates a wide range of organ sizes, and allows longer support times. <h3>Methods</h3> Silicone-infused thermoplastic polyurethane was used to construct a flexible biocompatible structure to closely envelop the heart. The cone-shaped bottom of the envelope serves as a drainage port to recirculate coronary sinus blood to a pump and oxygenator. Additional ports allow for aortic perfusion, left ventricular venting, deairing, pacing, ECG, and other monitoring. T-slot aluminum extrusion frames were constructed to suspend the device. A microprocessor with custom-built software was incorporated into the design to monitor and store key parameters, such as ECG, temperature, pressure in various compartments, and flow. <h3>Results</h3> Feasibility of ex-vivo perfusion was tested in a mock-loop setup. The design allowed use of commercially available and clinically approved oxygenators (Quadrox-i, Getinge, Sweden) and pumps (Rotaflow, Getinge, Sweden). Envelope design eliminated blood-air contact, while maintaining flow rates up to and above expected resting coronary blood flow values in adult hearts of 300ml/min. Flow consistency could be shown for extended runs of >3h. Perfusion of an isolated pig heart was performed to prove technical validity of the model. <h3>Conclusion</h3> We have developed an initial prototype for a novel ex-vivo organ perfusion capable of accommodating hearts of variable sizes from neonates to adults, ideally suited for the pediatric population. The system further aims at a reduction of blood trauma and foreign surface contact to increase support times without increasing inflammatory response and organ damage.

In vitro and in vivo evaluation of a novel bioresorbable magnesium scaffold with different surface modifications.

The novel Resoloy® rare earth magnesium alloy was developed for bioresorbable vascular implant application, as an alternative to the WE43 used in Biotronik's Magmaris scaffold, which received CE approval in 2016. Initially, the Magmaris showed very promising preclinical and clinical results, but the formation of an unexpected conversion product and a too fast loss of integrity has proven to be a flaw. The safety and efficacy of Resoloy, which is intended to be bioresorbed without any remnants, has been investigated in an in vitro degradation study and a porcine coronary animal model. Four different groups of scaffolds composed of Resoloy (Res) as the backbone material and additionally equipped with a fluoride passivation layer (Res‐F), a polyester topcoat (Res‐P), or a duplex layer composed of a fluoride passivation layer and a polymeric topcoat (Res‐PF) were compared to a Magmaris scaffold in an in vitro degradation test. Preclinical safety and efficacy of Res‐F and Res‐PF were subsequently evaluated in a coronary porcine model for 12 and 28 days. Scanning electron microscope, quantitative coronary angiography, micro‐computed tomography, histopathology, and histomorphometry analyses were conducted to evaluate preclinical parameters and degradation behavior of the scaffolds. Res‐PF with a duplex layer shows the slowest degradation and the longest supporting force of all test groups. The in vitro data are confirmed by the results of the in vivo study, in which Res‐PF exhibited a longer supporting force than Res‐F, but also caused higher neointima formation. Both studied groups showed excellent biocompatibility. A starter colonization of the strut area with cells during bioresorption was observed. The in vitro degradation test shows that a combination of MgF2 passivation and a PLLA topcoat on a Resoloy magnesium backbone (Res‐PF) leads to a much slower degradation and a longer support time than a Magmaris control group. In a preclinical study, the safety and efficacy of this duplex layer could be demonstrated. The beginning colonization of the degraded strut area by macrophages can be seen as clear indications that the resorption of the intermediate degradation product takes a different course than that of the Magmaris scaffold.

A poly(L‐lactic acid) monofilament with high mechanical properties for application in biodegradable biliary stents

AbstractIn this article, a poly(L‐lactic acid) (PLLA) monofilament with high mechanical properties which can be used to construct biodegradable biliary stents (BBS) is prepared. Compared with a commercial polydioxanone (PDO) suture, the PLLA monofilament has much higher Young's modulus. As a result, chronic outward force (COF) of the stent braided by PLLA monofilament is more than three times higher than that of the stent braided by PDO suture. Furthermore, by physicochemical indexes characterizations, it is acceptable that the PLLA monofilament has stable Young's modulus and higher elongation at break without brittle fracture risk during degradation in bile. In contrast, although PDO suture can also maintain Young's modulus well during degradation, its elongation at break is attenuated rapidly, which shows a high brittle fracture risk. These results indicate that PLLA monofilament is more suitable for constructing BBS with high COF, which are promising in treating more complex biliary strictures that need longer support time.

Quadriceps muscle weakness influences the gait pattern in women with knee osteoarthritis

BackgroundOsteoarthritis is the most prevalent rheumatic disease in the population and is characterized by limitation of main functional activities of daily living, as the gait. Muscle strength is a variable that may be related to performance in daily tasks.Therefore, we to analyze the gait pattern in individuals with knee osteoarthritis (KOA) and to determine associations of gait variables with the level of muscle strength of knee extensors.MethodsSixty-seven female volunteers divided into 2 groups, a KOA group (KOAG, n = 36, 66.69 ± 7.69 years) and control (n = 31, 63.68 ± 6.97 years), participated in the study. The volunteers walked on a 10-m platform at their usual gait speed, using 2 pressure sensors positioned at the base of the hallux and calcaneus. The mean step time, support and double support times, swing time and gait speed were calculated. The evaluation of the quadriceps isometric torque was performed in an extensor chair, with hip and knee flexion at 90°. The procedure consisted of three maximal contractions of knee extension. Peak torque was determined by the highest torque value obtained after the onset of muscle contraction. For statistical analysis, one-way ANOVA and Pearson’s correlation were used, with p < 0.05.ResultsThe KOAG had a 54.76% longer support time, a 13% longer step time (p < 0.001), a 30% decrease in swing time (p < 0.001) and a 10.7% decrease in gait speed (p = 0.001) compared with controls. The quadriceps isometric torque was 34% (p = 0.001) lower in the KOAG. There was a correlation between kinematic variables and quadriceps torque.ConclusionWeakness of the quadriceps muscle in women with KOA influences gait pattern, resulting in reduced speed associated with a shorter swing time and longer support time.

A longer waiting game: Bridging children to heart transplant with the Berlin Heart EXCOR device—the United Kingdom experience

Mechanical circulatory support (MCS) is used to support children with end-stage heart failure to heart transplant. This was a retrospective cohort study of 7 years' experience with the Berlin Heart (BH) EXCOR (Berlin Heart AG, Berlin Germany) paracorporeal ventricular assist device (VAD) in 2 United Kingdom (UK) pediatric heart transplant centers and the effect of this program on the UK pediatric heart transplant service. Of 102 children who received BH support, 84% survived to transplant or BH explant and 81% survived to discharge. Neither age nor duration of support influenced outcome. Stroke, ongoing requirement for ventilation while on BH, and diagnosis other than dilated cardiomyopathy were the only independent mortality risk factors. Children who weighed < 20 kg had significantly (p = 0.03) longer support times than bigger children. The number of children treated with a BH increased over time (p = 0.01). Currently > 50% of pediatric heart transplants are bridged with a BH; however, pediatric transplants per year have not increased significantly (p = 0.07) CONCLUSIONS: BH use in the UK has allowed significant increases in the number of children with end-stage heart failure who can be successfully bridged to transplant and the length of time they can be supported. The total number of transplants has not increased.

First Berlin Heart EXCOR Pediatric VAD Interhospital Transports of Nonambulatory Patients with the Ikus Stationary Driver

Ventricular assist devices (VADs) are increasingly being used in pediatric patients to support cardiac failure. As more centers adopt this technology, there may be a need to transport these patients over long distances to facilitate patient care and organ transplantation. Food and Drug Administration indications for use state only that the patient must be a candidate for transplantation and does not place restrictions on the transplant capabilities of the implanting medical center. Nontransplanting institutions are able to use this technology with a predetermined agreement to transfer the patient to a partnering transplant center. We report the first two cases of interhospital air and ground transport of nonambulatory or intubated pediatric (<13 kg) patients supported by Berlin Heart EXCOR pediatric VADs and Ikus stationary drivers. We present our protocol for transporting this delicate patient population. In addition, we discuss important challenges encountered on these operations regarding vehicle transfers and the management of vehicle power supply. These two cases demonstrate that the transportation of pediatric patients on Berlin Heart VADs is feasible and safe and should be considered a treatment option in certain situations.

Results of elective repair at 6 months or younger in 277 patients with tetralogy of Fallot: A 14-year experience at a single center

To report practice and outcomes in infants undergoing elective repair of tetralogy of Fallot. A review of a retrospective cohort of elective complete repair of infants age 6 months or younger from 1995 to 2009 was performed. Patients were excluded because of previous interventions, hypercyanotic episodes, intensive care admissions, additional major cardiac defects, or if they were not discharged after birth. Length of stay, mortality, and complications were recorded. Association was determined using logistic or linear regression models and univariate testing determined the multivariate model. There were 277 patients included. The hospital mortality rate was zero. A total of 87.4% of patients were discharged home within 7 days of repair, and 21.6% of patients were discharged on or before the third postoperative day. The postoperative course was uncomplicated in 245 patients (88.4%). Longer support time was associated independently with increased odds of complications (P < .001). Longer support time, younger age, chromosomal abnormality, and presence of a complication were associated independently with a longer hospital stay (all P < .001). Patients younger than 3 months (n = 110) had a longer median hospital stay (4 vs 3 days; P < .001) and longer support times (77.3 ± 35.1 min vs 66.4 ± 34 min; P < .01). Elective tetralogy of Fallot repair was performed at 6 months or younger with low morbidity, no hospital mortality, and an 11.6% complication rate. Longer support times, lower weight, chromosomal abnormalities, and complications were associated with a significantly increased duration of hospital stay.

Bridge to Lung Transplantation with Veno-Venous Extracorporeal Membrane Oxygenation for End-Stage Lung Disease: A Single Center Experience

Purpose Veno-venous extracorporeal membrane oxygenation (ECMO) has been reported as a successful treatment strategy for patients with refractory, albeit reversible lung disease. Its use as a bridge to transplantation (BTT) for patients with irreversible lung disease is less well described. We report our institutional experience with ECMO as a bridge to transplant. Methods and Materials All patients with end stage lung disease who were placed on VV ECMO as BTT between 2009 and 2012 were identified. Underlying disease, indication for ECMO support, time from intubation to cannulation for ECMO, duration of support and outcomes were analyzed. Results During that time period, 28 patients were placed on ECMO as BTT. Underlying disease included restrictive lung disease (n=22), obstructive lung disease (n=5) and pulmonary hypertension (n=1). The median interval from intubation to initiation of ECMO was four days (range 0-15 days). The median duration of support was 12 days (range 1-155 days). Thirteen patients received lung transplants and fifteen patients died. Of the thirteen patients who were successfully BTT, seven patients survived to discharge, three remain in the hospital and three died. Conclusions The prognosis of patients with end stage lung disease is poor. Despite longer support times than previously reported series, our experience demonstrates the efficacy of ECMO as a bridge to transplant.

The Pediatric Mechanical Circulatory Support Program in Innsbruck, Austria, and the Impact of Such Programs on Lack of Donor Hearts in Europe

Strategy and results of the Innsbruck Mechanical Circulatory Support Program are presented, and the impact of such programs on pediatric heart transplantation (HTX) in Europe is discussed. Venoarterial extracorporeal membrane oxygenation (vaECMO) and ventricular assist devices (VADs) were used in 21 pediatric patients (median age 3.3 years, 2 days to 17 years) for acute heart failure (AHF) following a bridge or bridge-to-bridge strategy. Twelve patients were treated with vaECMO: eight were weaned after 2-10 days, two died, and two were switched to a VAD. Of the last, one was weaned 47 days later and the other underwent HTX 168 days later. In nine patients, VAD was implanted without preceding vaECMO. One such patient died (cerebral hemorrhage) after 236 days; of the remaining eight patients three were weaned and five underwent HTX. Waiting time for HTX (high-urgency status) varied from 4 to 372 days. Fifteen patients were discharged (follow up: 2-74 months); 14 are doing very well (New York Heart Association (NYHA) Functional Classification Class I, neurologically normal), whereas one suffers from severe neurologic damage, presumably from resuscitation before vaECMO. Data from Eurotransplant on pediatric HTX in 2004, 2005, and 2006 (33, 49, and 34 transplanted hearts, respectively; recipients <16 years of age) are discussed. Mechanical circulatory support (MCS) substantially improves survival with AHF in pediatric patients. Medium-term support (up to 400 days in our patients) is possible and outcome of survivors is excellent. Wide spread use of MCS might slightly aggravate the lack of donor organs, which could result in longer support times.