Artificial organs最新文献

Introduction: Left ventricular assist device (LVAD) therapy may lead to an aortic regurgitation, limiting left ventricular unloading and causing adverse events. Whether concomitant aortic valve replacement may improve outcomes in patients with preoperative mild-to-moderate aortic regurgitation remains unclear.

Methods: A retrospective propensity score-matched analysis of adult patients with preoperative mild-to-moderate aortic regurgitation undergoing durable LVAD implantation between 01/01/2011 and 30/11/2021 was performed. Patients undergoing concomitant valve surgery other than biological aortic valve replacement were excluded, resulting in 77 with concomitant biological aortic valve replacement and 385 without.

Results: Following 1:1 propensity score matching, two groups of 55 patients with and without biological aortic valve replacement were obtained, (mean age 59 ± 11 years, 92% male, 59.1% HeartWare). Aortic regurgitation was mild in 72.7% and 76.4% and moderate in 27.3% and 23.6% in non-replacement and replacement cohorts respectively. The 30-day survival was 89.1% vs. 85.5% (p = 0.59), 1-year survival 69.1% vs. 56.4% (p = 0.19), and 2-year survival 61.8% vs. 47.3% (p = 0.10) in the non-replacement and replacement groups, respectively. After a mean follow-up of 1.2 years, non-replacement patients had a higher incidence of pump thrombosis (11 [20%] vs. 3 [5.5%], p = 0.022) and fewer major bleedings (2 [3.6%] vs. 11 [20%], p = 0.008).

Conclusion: Compared with those treated conservatively, patients with mild-to-moderate aortic regurgitation undergoing concomitant aortic valve replacement during LVAD implantation have a similar survival up to 2 years on support. Patients with concomitant valve replacement had a higher risk of bleeding complications but fewer pump thromboses.

Background: Preclinical and clinical studies have demonstrated the advantages of oxygenated hypothermic machine perfusion (HMPO₂) during kidney preservation. However, the optimal oxygenation levels during HMPO₂ remain undetermined. The aim of this study was to compare different levels of oxygenation (0%, 21%, 50%, and 100%) during 22 h of active oxygenated HMP (HMPO₂) using oxygen preloading by bubbling oxygenation in the preservation solution and continuous surface oxygenation during MP in a porcine DCD model.

Methods: After 60 min of warm ischemia time, both kidneys of an 80 kg pig were procured and randomized to one of the following groups: (1) 22-h static cold storage (n = 6), (2) 22-h HMP without active oxygenation (n = 6), (3) 22-h HMPO₂ 21% O₂ (n = 6), (4) 22-h HMPO₂ 50% O₂ (n = 6), and (5) 22-h HMPO₂ 100% O₂ (n = 6). The primary outcome measure was to compare the different oxygen levels among the different groups assessed by cortex kidney tissue oxygen partial pressures (tpO₂).

Results: Continuous HMPO₂ resulted in a significant modification of cortex kidney tpO₂. In addition, tpO₂ was dependent on the percentage of oxygenation. One hundred percent oxygen resulted in a significantly higher tpO₂ compared to all other study groups. In line with that, ATP resynthesis was significantly higher in the HMPO₂ 100% group.

Conclusions: This study demonstrates that continuous HMPO₂ results in a significant modification of tpO₂ compared with SCS, and the degree of tpO₂ is positively correlated with the percentage of active oxygenation during HMP. Metabolic profile analyses (ATP resynthesis) suggest that the aerobic mechanism is better supported with higher oxygen levels (50% and 100% oxygenation).

Background: Artificial anal sphincter is a novel method for the treatment of fecal incontinence. Aiming at the problems of complex mechanical structure, high mechanical failure rate, large volume and poor biocompatibility of existing artificial anal sphincters, this article proposes a novel flexible artificial anal sphincter with bionic structure.

Methods: A novel flexible artificial anal sphincter was proposed with bionic structure by analogy with the puborectalis, flexible transmission by flexible tendons, good biocompatibility by using thermoplastic urethane and medical silicone, small size and lightweight. The interaction between the rectum and the artificial anal sphincter is simulated by the finite element analysis, and the changes of the anorectal angle and the stress during the traction process of the rectum are analyzed.

Results: The results suggest that the formed anorectal angle of <90° may effectively control defecation, so the effectiveness of the artificial anal sphincter is preliminarily verified. When the traction angle was 71° and the intestinal tube was basically closed, the maximum equivalent stress was 148.45 kPa, the maximum and minimum principal stress were 88.37 and 82.74 kPa, which were all below the safety pressure that initially verified the safety of the artificial anal sphincter.

Conclusion: The novel flexible artificial anal sphincter may effectively reduce the stress between the device and the rectum and improve the biomechanical compatibility.

Background: The objective of this study is to determine the incidence of major bleeding events in patients implanted with continuous flow left ventricular assist devices (CF-LVADs) bridged with enoxaparin (LMWH) compared to intravenous unfractionated heparin (IV UFH) for a subtherapeutic INR on warfarin.

Methods: A single-center, retrospective, cohort study was conducted including patients with CF-LVADs implanted between January 1, 2012 and July 1, 2020 who received at least one inpatient dose or outpatient prescription for LMWH or IV UFH at least 60 days after CF-LVAD implantation. The primary endpoint was the incidence of major bleeding.

Results: In total, 176 orders were screened and 90 orders in 62 unique patients were included. Major bleeding and thromboembolic events occurred in 1 (2.5%) versus 4 (10.0%) orders (p = 0.36) and 3 (7.5%) versus 1 (2.5%) orders (p = 0.62) in the LMWH and IV UFH groups, respectively. One patient had a fatal thromboembolic event in each group. More patients receiving IV UFH had minor bleeding events (10 [25.0%] vs. 3 [7.5%]; p = 0.03).

Conclusions: There was no difference between bleeding and thromboembolic events in patients implanted with CF-LVADs prescribed LMWH or IV UFH for bridging of subtherapeutic INRs. Larger prospective randomized data are needed to validate these findings.

Background: There is a lack of documented cases regarding complications during ECMO transfer in middle-income countries. Using portable ECMO devices facilitates patient transport but entails significantly higher costs, necessitating evidence of their practical utility. This study aims to describe complications during ECMO transfer in Argentina and to compare complication rates between the integrated portable ECMO and non-portable ECMO systems.

Methods: A multicenter observational retrospective study was conducted across four high-complexity hospitals in Argentina. Patients over 18 years old who underwent ECMO transfer between January 2017 and July 2023 were included. Complications were classified based on the Ericsson severity classification, a widely accepted system that categorizes complications based on their severity and the need for immediate organ support. The effect of the ECMO systems (portable and non-portable ECMO system) on complication rates was assessed using logistic regression weighted by inverse probability weighting (IPWT) analysis after propensity score assessment to adjust for confounders.

Results: The study included 65 patients who were transferred for ECMO. Complications occurred in 40% (95%CI: 28%, 52%; n=26) of transfers, with grade 2 complications being the most prevalent at 20% (95%CI 11%, 32%; n=13). Integrated portable ECMO systems were associated with fewer complications during ECMO transfer, showing a crude OR of 0.25 (95%CI 0.08, 0.75), and after adjustment by IPWT, an OR of 0.27 (95%CI 0.08, 0.93).

Conclusions: ECMO transfers in middle-income countries exhibit complication rates similar to those in high-income countries. Our study found fewer complications in transfers using integrated portable ECMO systems and those involving distances exceeding 100 km. These findings suggest that the use of portable ECMO systems, despite their higher costs, may be beneficial in reducing complications during patient transport in middle-income countries.