International Journal of Medical Devices doi: 10.3390/ijmd1010005

Authors: Weilue He Ethan Sommer Megan C. Frost

Background: Terminal sterilization is a regulatory requirement for most medical devices. However, conventional sterilization methods can compromise temperature-sensitive and biologically reactive components. This study evaluates the sterilization efficacy and preliminary material compatibility of a novel room-temperature sterilization modality using gaseous nitric oxide (NO). Methods: NO was delivered using standardized Sterile Solution® (Sterile State Inc., Grand Rapids, MI, USA). To characterize microbial inactivation kinetics, the decimal reduction time (D-value) of commercial biological indicators (BIs), Bacillus atrophaeus Apex® Discs, was determined in accordance with ISO 11138. BIs were exposed to NO at ambient temperature (18.9–22.0 °C). D-values were calculated using both the survivor curve method (Holcomb–Spearman–Karber) and the fraction-negative method (Stumbo–Murphy–Cochran). Material compatibility was evaluated across four primary medical device and packaging plastics, including polyethylene (PE), poly(ethylene terephthalate) (PET), polypropylene (PP), and polyvinyl chloride (PVC)), representing 70% of the industry market share. After exposure to NO sterilization cycles, mechanical and chemical properties were characterized using tensile testing (ASTM D882-18) and Fourier-transform infrared (FTIR) spectroscopy relative to unexposed controls. Results: The calculated D-values ranged from 1.31 (78.7 min) to 1.34 h (80.4 min) across both analytical methods, corresponding to an estimated 6-Log reduction in Bacillus atrophaeus BIs in approximately 8 h. Meanwhile, plastics exposed to the NO sterilization cycle showed no significant changes in mechanical or chemical properties. Conclusions: These findings demonstrate that NO sterilization achieves semi-Log-linear inactivation of a widely accepted BI and represents a promising alternative to conventional gaseous sterilization methods such as ethylene oxide (EtO). By achieving a reliable sterility assurance level under mild ambient conditions without adversely affecting the physicochemical properties of commonly used plastic materials, NO sterilization may offer a practical solution for thermosensitive and delicate medical devices.

International Journal of Medical Devices doi: 10.3390/ijmd1010004

Authors: Amr Seifelnasr Xiuhua Si Jinxiang Xi

Efficient aerosol delivery to the maxillary sinuses remains challenging because narrow ostia limit sinus entry. This in vitro study evaluated whether low-frequency, large-amplitude pulsatile flow can deliver humidifier-generated water aerosols to the maxillary sinuses, compared retention with e-vapor under identical conditions, and identified setup modifications required for water aerosol transport. Experiments used three transparent anatomically realistic sinonasal models: two single-passage models with narrow-long (NL) and wide-short (WS) ostial geometries, and one dual-passage dual-maxillary-sinus (RL) model. Water aerosols and e-vapor were delivered using a modified servo-actuated syringe generator under fixed conditions: 50 mL stroke volume, 0.33 Hz frequency, 1 L/min vacuum-induced flow, and 1.5 min delivery. Water aerosols were larger than e-vapor aerosols (D50 = 5.553 µm vs. 3.394 µm) and required setup modification because of greater wall interactions, condensation, coalescence, and transport losses. Pulsatile delivery achieved plume entry into all tested maxillary sinuses. E-vapor showed greater retained mass than water aerosols in NL (1.060 ± 0.152 vs. 0.540 ± 0.089 mg) and WS (0.800 ± 0.071 vs. 0.520 ± 0.110 mg). Water-sensitive Sar-Gel visualization confirmed bilateral water aerosol retention in RL. These findings support pulsatile delivery as a feasible strategy for water aerosol transport to the maxillary sinuses but with a lower efficiency than e-vapor aerosols.

International Journal of Medical Devices doi: 10.3390/ijmd1010003

Authors: Fotios Leventis Hani Ali-Ghosh Sanjay Asopa Sunil K. Ohri

Background: Transcatheter mitral valve implantation (TMVI) represents an evolving therapeutic strategy for patients with severe mitral valve disease who are at high or prohibitive risk for conventional surgery. Since the first human implantation in 2012, multiple dedicated and adapted devices have entered clinical investigation, yet only one dedicated system—the Tendyne prosthesis (Abbott Structural)—holds regulatory approval. This systematic review evaluates the current landscape of available and emerging TMVI devices, examines the clinical outcome data, discusses key indications and limitations, analyses the role of computed tomography (CT) in predicting left ventricular outflow tract (LVOT) obstruction caused by the unopposed anterior mitral leaflet, and compares TMVI outcomes with conventional surgical mitral valve replacement (SMVR) in the specific context of severe mitral annular calcification (MAC). Methods: A systematic search of PubMed, EMBASE, Cochrane Central, and Web of Science was performed for studies published from January 2010 to March 2025 reporting outcomes of TMVI in native valve disease, valve-in-valve (ViV), valve-in-ring (ViR), or valve-in-MAC (ViMAC) procedures. Studies reporting CT-based LVOT planning, neo-LVOT quantification, and LVOT obstruction outcomes were specifically sought. Meta-analyses comparing TMVI with redo surgical mitral valve replacement were included. A total of 63 studies (n > 12,000 patients across all subgroups) were included in the qualitative synthesis; 28 studies were included in the quantitative synthesis. Results: Nine dedicated TMVI devices are currently under clinical investigation, with only Tendyne holding CE Mark and FDA approval. In ViV/ViR cohorts, TMVI was associated with significantly lower in-hospital mortality (OR 0.72, 95% CI 0.57–0.92; p = 0.008) and 30-day mortality (OR 0.49; p = 0.04) compared with redo SMVR, with no significant difference at one year (OR 1.03; p = 0.91). In ViMAC cohorts, 30-day mortality ranged from 14 to 24%, which was substantially higher than in the ViV outcomes. CT-based virtual simulation of the neo-LVOT area—the residual outflow tract created by anterior mitral leaflet displacement—is the most validated predictor of LVOT obstruction, with a threshold of ≤1.7 cm2 yielding 96% sensitivity and 92% specificity. The LAMPOON technique (laceration of the anterior mitral leaflet to prevent outflow obstruction) has expanded the eligibility for patients who were previously excluded due to LVOT risk. Surgical MVR in severe MAC carries a median 30-day mortality of 6.3% (range 0–27.3%), while ViMAC TMVI with dedicated devices yields 6.8% 30-day mortality, without a definitive randomised comparison. Conclusions: TMVI offers a viable alternative to redo surgery in high-risk patients with failed bioprostheses or rings. In severe MAC, both surgical and transcatheter approaches carry significant risk; patient selection, CT-guided LVOT planning, and use of dedicated devices are critical to optimising outcomes. The ongoing SUMMIT randomised controlled trial will provide the first high-quality comparative data. Future developments in transseptal delivery and LVOT-safe device architectures are expected to broaden the eligible population.

International Journal of Medical Devices doi: 10.3390/ijmd1010002

Authors: Keat Ghee Ong

The field of medical devices has no shortage of ideas [...]

International Journal of Medical Devices doi: 10.3390/ijmd1010001

Authors: Ziyu Wang Tiansong Wang Ming Chen Jiahui Chen Arielle J. Perez Januka Budhathoki-Uprety Ashley C. Brown Jessica M. Gluck Martin W. King

As one of the most frequently performed surgeries worldwide, hernia repair addresses a pathological condition caused by muscle weakness and defects in the muscle wall. Despite its prevalence, hernia surgery remains challenging due to complications such as organ occlusion, seroma, persistent pain, tissue adhesions, and wound infection. Surgical meshes have become the preferred choice for abdominal wall hernia repair, aiming to restore the physical integrity and functionality of the musculofascial layers. Although various types of hernia mesh are available on the market to mitigate post-reconstruction complications, none have proven to be a perfect solution for reducing hernia recurrence. In this review, we explore the etiology of hernias, the materials and structures used in designing hernia meshes, and the emerging multifunctional trends aimed at addressing not just one aspect of the complications but the overall range of complications following hernia repair. We discuss strategies to mitigate side effects and establish the characteristics of ideal hernia repair meshes. Lastly, this review outlines future research directions for developing successful hernia repair solutions, emphasizing the need for innovative approaches to enhance patient outcomes and minimize recurrence rates.