Superior venous drainage in the "LifeBox": a portable extracorporeal oxygenator with a self-expanding venous cannula

Virtually Wall-Less versus Standard Thin-Wall Venous Cannula in the Minimally Invasive Mitral Valve Surgery: Single-Center Experience

Background and Objectives: Minimally invasive cardiac surgery (MICS) has been developing since 1996. Peripheral cannulation is required to perform MICS, and good venous drainage and a bloodless field are crucial for the success of this procedure. We assessed the benefits of using a virtually wall-less cannula in comparison with the standard thin-wall cannula in clinical practice. Materials and Methods: Between January 2021 and December 2022, we evaluated 65 elective patients, who underwent isolated minimally invasive mitral valve surgery. Both the virtually wall-less and the thin-wall cannulas were placed through a surgical cut-down. Patients' characteristics at baseline were similar in the two groups, except for the body surface area (BSA), which was greater in the virtually wall-less group compared to the thin-wall one. In the standard group, the size of the cannula was chosen depending on the patient's BSA, and the choice of the Smartcannula was based on their height. Results: There were no significant differences between the two groups in terms of negative pressure applied, target flow achieved, hemolysis, the need for blood transfusion, and the post-operative increases in liver and renal enzymes. However, in all the patients, the estimated target flow was achieved, thereby showing the better hemodynamic performance of the virtually wall-less cannula, since, in this group, the patients' BSA was significantly greater compared to the thin-wall group. Ultimately, the mean cross-clamp time, as an indirect index of the effectiveness of the venous drainage, is shorter in the virtually wall-less group compared with the thin-wall group. Conclusions: The virtually wall-less cannula should be preferred in minimally invasive mitral valve surgery due to its superior performance in terms of venous drainage compared with the standard thin-wall cannula.

Research progress of portable extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is primarily used for the supportive treatment of patients suffering from severe cardiopulmonary failure. With the continued development of ECMO technology, the relevant scenarios also extend pre-hospital and inter-hospital. In order to meet the needs of emergency treatment in communities, disaster sites and battlefields, inter-hospital transfer and evacuation; miniaturized and portable ECMO has become a current research hotspot.

AREA COVERED

The paper first introduces the principle, composition and common modes of ECMO and summarizes the research status of portable ECMO, Novalung and wearable ECMO, analyzes the characteristics and shortcomings of existing equipment. finally, we discussed the focus and development trend of portable ECMO technology.

EXPERT OPINION

Currently, portable ECMO has many applications in interhospital transport and there are various studies on portable and wearable ECMO devices, but the development of portable ECMO still faces many challenges. In the future, research related to integrated components, rich sensor arrays, Intelligent ECMO system and lightweight technology can make future portable ECMO more suitable for pre-hospital emergency and interhospital transport.

[Patient transport and networks for use of extracorporeal life support]

Neue Technologien und die kontinuierliche Weiterentwicklung extrakorporaler Unterstützungssysteme haben das Anwendungsspektrum des Extracorporeal Life Support (ECLS) in den letzten Jahren erweitert. Neben dem Einsatz im kardiogenen Schock oder unter Reanimation nehmen die Anfragen zur Übernahme instabiler Patienten aus peripheren Krankenhäusern zu. Durch organisatorische Herausforderungen wie die Etablierung von Netzwerken und ein strukturiertes Teamtraining aller Beteiligten ergibt sich eine rasche Verfügbarkeit des ECLS-Teams, um schnell beim zu versorgenden Patienten einzutreffen.

Performance Increase in Venous Drainage for Mini-Invasive Heart Surgery: Superiority of Self-Expanding Cannulas

Objective

Originally, the Smartcanula principle (collapsed insertion and expansion in situ) was developed for venous drainage by gravity. However, in minimally invasive surgery, augmentation with either constrained force vortex pumps or vacuum is often used. The current study was set up to assess whether smaller diameters of self-expanding venous cannulas are sufficient in conjunction with venous drainage augmentation resulting in smaller access orifices.

Methods

To evaluate cannulas intended for cardiopulmonary bypass, an in vitro circuit was set up with silicone tubing between the test cannula encased in a lower reservoir, the centrifugal pump, and after an upper reservoir. Afterload was set arbitrarily at 60 mm Hg using a centrifugal pump. The pressure value was measured using Millar pressure transducers. Flow rate (Q) was measured using an ultrasonic flow meter calibrated with volume tank and timer. Revolutions per minute of the centrifugal pump were calibrated with a stroboscope. Data display and data recording were controlled using a Lab View application. Self-expanding (24F Smartcanula) and control (25F Biomedicus) cannulas were used.

Results

Sixty measurements were recorded. At pump speed of 1500, 1570, 2000, 2500, and 3000 rpm, the Q values were 3.6, 5.2, 6.6, 9.3, and 11.8 L/min for the 24F self-expanding cannula and 3, 4.3, 5.4, 7.5, and 9.3 L/min for the control cannula. The pressure values were 3.6, −5.4, −15.9, −45.3, and 80.6 mm Hg. Biomedicus 25F showed Q values from 16% to 19% less as compared with 24F Smartcanula. The pressure values were 6, 7, 4, 2, and 2 times more as compared with 24F Smartcanula.

Conclusions

Our experimental evaluation demonstrated the superior performance of the Smartcanula with its self-expanding design in comparison with the reference commercially available standard cannulas. The Smartcanula with its small diameter is particularly welcome for minimally invasive surgery.

A systematic review of effectiveness and economic evaluation of Cardiohelp and portable devices for extracorporeal membrane oxygenation (ECMO)

In recent years, there have been substantial advancements in the development of different technologies for extracorporeal membrane oxygenation (ECMO) for in-hospital and out of hospital applications. However the effectiveness of these devices is not clearly known. The objective of this study was to evaluate the cost-effectiveness of Cardiohelp compared to other portable ECMO devices. In this systematic review, we searched Medline (via Ovid), Embase, Pubmed, Cochrane Library, SCOPUS, CRD and NICE. Articles were assessed by two independent reviewers for eligibility and quality of the evidence. Studies which compared Cardiohelp to other ECMO devices were included. Seven out of 1316 publication were included in this review, three of them were clinical trials and four were observational studies. The majority of the studies had limited quality. According to the measures of safety, Cardiohelp had safer technological features, but on the other hand, was more complex to use. Considering the effectiveness, Cardiohelp was not statistically different from other technologies. Cardiohelp showed slightly better performance than Centrimag in terms of cost per patient and cost-effectiveness. However, when clinical criteria were used to select the patients with good prognosis to administer the ECMO, incremental cost utility ratios (ICURs) for both Cardiohelp and Centrimag were below the level of willingness-to-pay threshold. According to the measures of safety and effectiveness, ECMO with Cardiohelp was not considerably different from other evaluated technologies. Moreover, ECMO with Cardiohelp or Centrimag can be considered cost-effective, provided that the patients are selected carefully in terms of neurological outcomes.