ASAIO Journal最新文献

Extracorporeal life support (ECLS) requires specialized cannulas for vascular access that are dependent on each patient's needs, size, and unique vascular anatomy. There are currently no commercially available drainage cannulas suitable for patients smaller than 1.5 kg. This study presents the development of a novel 6 Fr cannula for blood drainage to be used in these small patients. Cannulas were manufactured using stereolithography three-dimensional (3D) printing on Form 3 and Form 3B printers and tested in vitro using 3% glycerol. Drainage pressure at 100 ml/min was -39 ± 2 and -42.3 ± 9 mm Hg, for Form 3 and Form 3B, respectively. Maximum flow rate and drainage pressures were 185.8 ± 15 ml/min and -80 ± 2 mm Hg and 165 ± 21 ml/min and -85.7 ± 12 mm Hg for Form 3 and Form 3B, respectively. Three Form 3B cannulas were tested in vivo in an ECLS piglet model, the best of which had a maximum blood flow rate of 139 ml/min at -32 mm Hg drainage pressure. Cannulas 3D-printed using the Form 3 and Form 3B printers exhibited appropriate size and flow rates (~100 ml/kg/min) for ECLS needed to support premature patients with minimal complexity in the fabrication process. These cannulas should be optimized in preclinical research using translational models.

Cirrhosis was previously listed in Extracorporeal Life Support Organization (ELSO) guidelines as an absolute contraindication for venovenous extracorporeal membrane oxygenation (VV ECMO) and has since been removed. Minimal data report ECMO outcomes for this population, and thus little guides their ECMO candidacy decisions. We queried the ELSO Registry for all patients with cirrhosis who underwent VV ECMO between January 2014 and August 2024 to characterize outcomes compared with a propensity-matched cohort and to identify predictors of survival. Of 48,267 initial VV ECMO runs, 72 patients had cirrhosis (mean age 52 years, 56% male). Twenty (28%) patients survived to hospital discharge compared with 44% survival in the propensity-matched cohort. There were no statistically significant differences in ECMO complication rates or duration of support. Similarly, there were no statistically significant differences in survival and complication rates between patients with cirrhosis and complicated cirrhosis. Univariate and multivariate regression analyses did not identify reliable predictors of mortality. Overall, ECMO outcomes in patients with cirrhosis are worse than all-comers on ECMO but not substantially different than other broadly accepted ECMO indications such as extracorporeal cardiopulmonary resuscitation (ECPR). Until further data emerge, these data may be helpful to centers considering VV ECMO in patients with cirrhosis.

Computational fluid dynamics (CFD) is increasingly important in biomedical engineering; however, its use in medical device design remains constrained by regulatory requirements for model validation and verification. To address this, the Food and Drug Administration (FDA) proposed a benchmark nozzle geometry for standardized validation. This study employs a turbulence-based hemolysis model-the Ozturk-Papavassiliou-O'Rear (OPO) model-to investigate the FDA nozzle and identify red blood cell (RBC) damage caused by eddy structures similar in size to RBCs. Flow simulations were conducted for sudden contraction (SC) and gradual cone (GC) nozzle configurations at inlet velocities of 0.46 and 0.6 m/s (throat Reynolds of 3,500 and 6,500). Regions where eddies fall within the damaging Kolmogorov length scale were identified and analyzed. Hemolysis predictions were made using the eddy surface area distribution and validated against experimental hemolysis index (HI) data. For SC, a qualitative indicator, the cumulative eddy surface area of 6-20 μm, was provided; a numerical HI was postponed until a recalibration specific to SC and independent verification. For GC, the OPO model reproduced experimental trends in hemolysis risk localization but underpredicted absolute HI. These findings suggest that the OPO model offers a viable approach to predicting turbulence-resolved hemolysis in medical device design.

Venovenous extracorporeal membrane oxygenation (V-V ECMO) is a life-saving organ support for patients with severe respiratory failure. One of the possible complications involves cannula positioning, but the literature has largely focused on recirculation. We report five cases, from a cohort of 320 patients treated at a high-volume ECMO center, in which the tip of the long, non-multiperforated return cannula in a femoro-femoral V-V ECMO configuration inadvertently crossed the interatrial septum. This resulted in a veno-left atrial (V-LA) configuration with a massive right-to-left shunt of hyperoxygenated blood. The malposition was not clinically evident during the ECMO run and only became apparent during weaning attempts, when abrupt desaturation occurred. In retrospect, all patients exhibited strikingly high arterial partial pressure of oxygen (PaO₂) levels, absent recirculation, low sweep gas requirements, and excellent exercise tolerance-features that may help raise clinical suspicion. All cases were ultimately resolved by cannula repositioning, and no interatrial defect was identified in follow-up among the four survivors. Inadvertent V-LA ECMO is a rare but underrecognized complication. Early recognition is essential to avoid misinterpreting this phenomenon as treatment failure during weaning. Although it carries potential risks, such as systemic embolism or left atrial overload, it may also confer physiological benefits in selected clinical scenarios.

Machine perfusion (MP) is commonly used donors after circulatory death (DCD) heart transplants (HT) as direct procurement and perfusion technique, limited data exist regarding MP use for DCD donors from extended distances (ED). In the United Network for Organ Sharing (UNOS) database, 725 isolated DCD-HTs were identified between October 18, 2018, and December 31, 2023, excluding re-transplants and multi-organ transplants. Outcomes were compared according to travel distances: control (≤500 miles, n = 465) versus group ED (>500 miles, n = 260). Propensity score matching was performed (239 pairs). Travel distance was longer in group ED (224 [108-363] vs . 720 [576-903] miles; p < 0.001), as was time from cross-clamp to implantation (5.4 [3.8-6.3] vs . 6.8 [5.7-8] hours; p < 0.001). One year survival was comparable between groups (control, 92.4 ± 2.5% vs . group E, 91.8 ± 3.6%; p = 0.29). Extended distances donor was not associated with mortality (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.43-1.53; p = 0.51). Cross-clamp-to-implantation time >8 hours was associated with mortality (reference: 0-4 hours; HR = 4.04; 95% CI = 1.50-10.86; p = 0.006), while 4-8 hours was not (HR = 1.35; 95% CI = 0.57-3.2; p = 0.497). In conclusion, DCD-HT with donors from ED using MP showed similar transplant outcomes compared with DCD-HT with donors within 500 miles. However, donor cross-clamp to implantation time >8 hours was associated with worse survival, which may be considered for donor and recipient selection.

The storing of dry-assembled and primed extracorporeal membrane oxygenation (ECMO) circuits is common practice and endorsed by the Extracorporeal Life Support Organization (ELSO) for up to 30 days. We conducted an anonymous survey among chief perfusionists in German neonatal and pediatric ECMO centers to identify key parameters of the actual clinical practices. Ten of 15 (67%) participating centers do not pre-assemble and pre-prime circuits in apprehension of future patients. The average storing times in 33% of the centers exceed the ELSO recommended 30 days up to 150 days. Longer storing times may be the result of less annual cases compared with adult ECMO. The addition of concentrated erythrocytes in the priming fluid may be one reason for ad-hoc de-airing. None of the participating centers treats children exclusively, omitting the center's overall experience as reason for the different practices in adults and children. Nonetheless, the average time required for assembly and de-airing was extended by 40% compared with adult ECMO while the perceived urgency in emergency situations was increased. Overall, this study shows distinct differences between adult and neonatal/pediatric ECMO regarding circuit preassembly and prepriming that indicate the need for improved standard operating procedures and specific research.

Computational cardiovascular models hold promise for simulations in education and bedside clinical decision support. To enhance patient-specific modeling, individual anthropometrics are imperative, as physiology varies with body size due to fundamental energetic relations expressed in allometric scaling laws. We hypothesize that computational cardiovascular models can be advanced towards individualization by implementing scaling laws based on patient age, weight, height, and sex. A scaling methodology was developed for the lumped-parameter cardiovascular model Aplysia Cardiovascular Lab. Male and female subjects were based on Swedish growth charts from birth to adult size and simulated to test model realism. Realistic physiology was generated for underweight, overweight, and average male and female patients from birth to 80 years. Model output included comprehensive measures of hemodynamics, cardiac function, respiratory function, gas exchange, ventilatory mechanics, and energy expenditure. In comparison to published data, aggregate Z scores for infant, pediatric, and geriatric simulations were 1.16, 0.69, and 0.10, respectively. Allometric scaling laws can be used to generate parameter sets of males and females of disparate sizes and ages in line with published data. This sets the stage for modeling diverse patient populations and novel approaches toward individualized clinical applications.

The impact of hemolysis during microaxial flow pump (mAFP; Impella, Danvers, Massachusetts, US) support on early outcomes after durable left ventricular assist device (d-LVAD) implantation is unknown. Three hundred and eleven consecutive patients undergoing d-LVAD implantation after mAFP support (Impella 5.0/5.5 72.3%) were retrospectively included. The incidence and predictors of hemolysis (plasma-free hemoglobin >20 mg/dl or lactic dehydrogenase (LDH) >2.5-fold the upper reference limit) before d-LVAD implantation were assessed, along with its impact on early post-d-LVAD outcomes. The primary outcome was a composite of hemocompatibility-related adverse events (HRAEs: stroke/gastrointestinal bleeding/pump thrombosis). Hemolysis occurred in 40.8%. Impella 2.5/CP versus 5.0/5.5 was the single independent predictor of hemolysis (adj-hazard ratio [HR] = 2.68, 95% confidence interval [CI] = 1.04-6.94, p = 0.031). Post-d-LVAD HRAEs occurred more frequently among patients with hemolysis (31.9% vs. 20.6%; p = 0.041), mainly driven by hemorrhagic stroke and gastrointestinal bleeding. At multivariate analysis, hemolysis remained independently associated with HRAEs (adj-HR = 1.62, 95% CI = 1.02-2.58; p = 0.041). Patients with hemolysis were more likely to need a temporary right ventricular assist device following d-LVAD implantation (28.3% vs. 16.8%; p = 0.012), with no difference in mortality (23.6% vs . 21.2%; p = 0.355). In conclusion, among patients undergoing d-LVAD implantation with mAFP bridge, hemolysis is common, occurs more frequently among patients supported with Impella 2.5/CP, and is an independent predictor of post-d-LVAD HRAEs.