Minimally Invasive Evaluation of Venous Leg Ulcers in an Outpatient Setting Using Rapid Evaporative Ionization Mass Spectrometry Coupled with a Carbon Dioxide Laser

@article{Pruekprasert2025,
  title = {Minimally Invasive Evaluation of Venous Leg Ulcers in an Outpatient Setting Using Rapid Evaporative Ionization Mass Spectrometry Coupled with a Carbon Dioxide Laser},
  author = {Pruekprasert, Kanin and Tan, Matthew and Simon, Daniel and Ford, Lauren and Davies, Alun and Takats, Zoltan and Onida, Sarah},
  journal = {Journal of Vascular Surgery: Venous and Lymphatic Disorders},
  volume = {13},
  number = {2},
  year = {2025},
  publisher = {Elsevier},
  abstract = {Objectives Conventional mass spectrometry has been utilized for venous leg ulcer (VLU) evaluation; however, its translational applications in clinical settings have been limited due to the need of lengthy sample pre-preparation. Rapid evaporative ionization mass spectrometry (REIMS) is a new technique that allows for rapid acquisition of molecular spectra at ambient environment. This study introduces an innovative method for in vivo evaluation of VLU by integrating REIMS with a carbon dioxide (CO2) surgical laser. The aim is to develop a rapid and minimally invasive diagnostic platform suitable for outpatient use. Methods To enable machine coupling, customized 3D-printed interfaces and circuit designs were developed and validated using porcine tissues prior to the human study. In the outpatient setting, a low-power CO2 laser was applied directly to superficially ablate VLU tissues, generating aerosols that contained fragmented tissue samples for REIMS analysis. Molecular spectra were acquired both before and after biofilm removal from various regions of the ulcer, including the biofilm, ulcer bed, ulcer edge, and adjacent skin. Statistical methods such as Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were employed to develop a tissue classification model, which was subsequently cross-validated. Additionally, differential compound analysis was performed to identify specific molecular variations between different VLU tissue regions. Results A total of 1266 molecular profiles were obtained from 18 VLUs in 12 patients, corresponding to biofilm (n = 329), ulcer bed (n = 299), ulcer edge (n = 312), and adjacent skin (n = 326) (Fig 1). The tissue classification model among all tissue categories demonstrated an accuracy of 80.33% upon cross-validation. Excluding spectra from adjacent skin, the biofilm detection from ulcer tissues achieved a sensitivity of 88.72% and a specificity of 93.79%, with positive and negative predictive values of 88.45% and 93.94%, respectively. Differential compound analysis revealed significant variations of compounds between tissue categories, for example, upregulated phosphatidylserine and phosphatidylethanolamine in the wound bed compared with the biofilm, and higher ceramide expression in the adjacent skin and ulcer edge compared with the wound bed (Fig 2). Conclusions The integration of REIMS with CO2 laser has demonstrated potential as a minimally invasive, rapid diagnostic platform for the evaluation of VLUs in outpatient setting. This platform enables precise tissue classification and biofilm detection and highlights molecular differences within VLU tissues. Future research should explore the clinical applications and potential integration of this technology into VLU management.},
}