S11 Utility of computed tomography (CT) to predict need for early surgery and recurrence after first episode of primary spontaneous pneumothorax (PSP)

Introduction and objectivesCT scanning is not presently advocated by British Thoracic Society (BTS) guidelines after first episode of primary spontaneous pneumothorax (PSP). There is emerging evidence that emphysema like changes and CT based Dystrophy Severity Score (DSS) can predict need for early surgical intervention and recurrence after first episode of PSP. We aimed to assess the role of CT based DSS during first episode of PSP in predicting need for early surgery and recurrence.MethodsRetrospective analysis of consecutive PSP episodes at first presentation (n=197) admitted to our institution from 01/01/2012 – 31/12/2017. Patients were categorized as low grade (score 0–3) or high grade (score 4–6) based on DSS on CT scan assessed by a thoracic radiologist who was blinded to eventual patient outcomes. DSS was calculated based on the type, number and distribution of blebs and bullae (adapted from World J Surg. 2016;40(5):1112–20).Results45 PSP patients had CT at first presentation. Median age was 31 years, 82% male and 73% smoker.8 patients had low grade DSS; all were managed non-surgically and none had recurrence over 12 months.37 patients had high grade DSS. 25 high grade DSS patients (67.5%) were managed by surgical intervention and 3 had contralateral recurrence over 12 months. 12 high grade DSS patients (32.5%) were managed non-surgically; 2 patients had ipsilateral recurrence over 12 months.Abstract S11 Table 1Comparison of low grade with high grade DSS for predicting early surgical intervention and rate of recurrence after first episode of PSP Low grade DSS (n= 8) High grade DSS (n= 37) P value Median age, years (IQR) 35 (23.5 – 46.7) 31 (24 – 34.5) 0.51 Male, n (%) 8 (100%) 29 (78%) 0.32 Right sided, n (%) 3 (37.5%) 17 (46%) 0.72 Current/Ex-smoker, n (%) 5 (62.5%) 28 (75.7%) 0.66 Median LOS, days (IQR) 5 (3.2 – 8.5) 8 (4 – 12) 0.52 Surgical intervention, n (%) 0 25 (68%) 0.0006 Recurrence at 1 year , n (%) 0 5 (13.5%) 0.57 ConclusionsCT based DSS seems to predict need for early surgery and recurrence after first episode of PSP. CT can be used to risk stratify patients after first episode of PSP and identify patients at high risk of failure of conventional treatment and early recurrence. Further prospective randomized studies are required to validate these findings.