The Thopaz+ portable digital system was evaluated by the Medical Technologies Advisory Committee (MTAC) of the National Institute for Health and Care Excellence (NICE). The manufacturer, Medela, submitted a case for the adoption of Thopaz+ that was critiqued by Cedar, on behalf of NICE. Due to a lack of clinical evidence submitted by the manufacturer, Cedar carried out its own literature search. Clinical evidence showed that the use of Thopaz+ led to shorter drainage times, a shorter hospital stay, lower rates of chest drain re-insertion and higher patient satisfaction compared to conventional chest drainage when used in patients following pulmonary resection. One comparative study of the use of Thopaz+ in patients with spontaneous pneumothorax was identified and showed shorter drainage times and a shorter length of hospital stay compared to conventional drainage. No economic evidence was submitted by the manufacturer, but a simple decision tree model was included. The model was improved by Cedar and showed a cost saving of £111.33 per patient when Thopaz+ was used instead of conventional chest drainage in patients following pulmonary resection. Cedar also carried out a sub-group analysis of the use of Thopaz+ instead of conventional drainage in patients with pneumothorax where a cost saving of £550.90 was observed. The main cost driver for the model and sub-group analysis was length of stay. The sub-group analysis was based on a single comparative study. However, the MTAC received details of an unpublished audit of Thopaz+ which confirmed its efficacy in treating patients with pneumothorax. Thopaz+ received a positive recommendation in Medical Technologies Guidance 37.