%0 Journal Article %A S Addley %A A Lechi %A A Bali %A V Asher %A S Abdul %A A Phillips %T 530 Evaluating the feasibility, morbidity and benefit of diaphragmatic surgery in advanced ovarian cancer. 74 consecutive cases over a 7 year period %D 2021 %R 10.1136/ijgc-2021-ESGO.420 %J International Journal of Gynecologic Cancer %P A245-A246 %V 31 %N Suppl 3 %X Introduction/Background*Diaphragmatic disease may be present in 90% of patients with stage IIIc/IV ovarian cancer. Whilst diaphragmatic involvement previously represented a potential obstacle to complete cytoreduction, techniques and surgeon experience – and hence feasibility of diaphragmatic debulking – have evolved since first described in 1989. With the most important prognostic indicator being achievement of R0 status, a preparedness to undertake diaphragmatic procedures demonstrates maximal cytoreductive effort for optimal patient outcome.Methodology All women undergoing diaphragmatic surgery for advanced tubo-ovarian or primary peritoneal carcinoma in a tertiary-referral cancer centre between 2014-2020 were identified and data collected retrospectively.Result(s)*74 patients were identified. Mean age was 63.7years. 78.4% (n=58) of cancers were tubo-ovarian and 21.6% (n=16) primary peritoneal. 51.4% (n=38) of patients had radiologically stage III disease; and the remainder (n=36) stage IV.The frequency of diaphragmatic procedures increased from 3/year in 2014 to 19/year by 2020. 40.5% (n=30) of surgeries were undertaken as primary debulking and 59.5% (n=44) as delayed primary surgery. 95.9% (n=71) were undertaken in addition to other ultra-radical procedures – 97.3% (n=72) of cases being assigned high or intermediate surgical complexity scores. The majority of patients had right-sided diaphragmatic disease. In 74.3% (n=55) of case, diaphragmatic peritoneal stripping was performed; resection in 50% (n=37); and in 5.4% (n=4) ablation. R0 was achieved in 91.9% (n=68). No procedure-specific intra-operative complications occurred. Mean surgery time was 433minutes and blood loss 1242 millilitres.All patients had planned post-operative admission to HDU/ITU. Mean length of in-hospital stay was 13.9days. 21 pulmonary complications occurred: 13.5% (n=10) developed pleural effusion requiring chest drain; 9.5% (n=7) pneumonia; 4.1% (n=3) pulmonary embolus and 1.4% (n=1) sub-splenic haematoma. Median overall survival was 55 months (95% CI 33.4-77.6)Abstract 530 Figure 1 Abstract 530 Figure 2 Conclusion*Surgeons should anticipate diaphragmatic disease in advanced ovarian or peritoneal cancer – and regard debulking of such an important prognostic factor. Diaphragmatic procedures appear feasible, without significantly increasing peri-operative morbidity in the context of ultra-radical surgery. %U https://ijgc.bmj.com/content/ijgc/31/Suppl_3/A245.2.full.pdf