Underlying endothelial dysfunction (EnD) may present in the early stage of ED or psychogenic ED. We retrospectively evaluated 191 ED patients with effective nocturnal penile tumescence and rigidity (NPTR) recording, including detailed medical and psychosexual history, International Index of Erectile Function-5 and vascular parameter. All patients were allocated into psychogenic and organic groups according to the NPTR test. Brachial artery flow-mediated dilation (FMD) was used to diagnose EnD, and ED patients were classified into two groups: non-EnD (FMDX10) and EnD (FMDo10). General and vascular parameters were compared between psychogenic and organic groups, and non-EnD and EnD groups with ED were compared in terms of NPTR parameters. In all, 48.7% and 51.3% patients were diagnosed as psychogenic and organic ED, respectively. 73.1% of the psychogenic patients had EnD and 39.8% organic patients had normal endothelial function. In all parameters, only the FMD value showed significant difference between psychogenic and organic ED groups (8.26±2.57 vs 9.16±2.76, P ¼ 0.020). No statistical difference was founded in NPTR parameters between non-EnD and EnD groups (P40.05). In conclusion, NPTR cannot effectively identify the underlying vasculogenic ED from psychogenic ED. Psychogenic causes may cause or aggravate EnD in these ED patients with normal NPTR.

respectively. In the other 24 patients (29.3%, 24/82), simple aspiration technique was ineffective. An opposite position (from prone to supine or vice versa) was applied, and a new biopsy puncture site was chosen for reaspiration. This procedure was successful in 22 patients but not in 2 patients who had to have a chest tube insertion. The complete and partial regression rates were 25.0% (6/24) and 66.7% (16/24), respectively. Applying the new method, the total effective rate of aspiration improved significantly from 70.7% (58/82) to 97.6% (80/82). Conclusion:The opposite position aspiration can be safe, effective and minimally invasive treatment for CT-guided lung biopsy-induced pneumothorax thus reducing the use of chest tube significantly. Advances in knowledge: (1) Opposite position aspiration can elevate the success rate of aspiration significantly (from 70.7% to 97.6% in our study); (2) this procedure is a safe, effective and minimally invasive treatment for pneumothorax caused by biopsy; and (3) opposite position aspiration is a useful technique to reduce the use of chest tube, which has clinical significance.