P474 Postoperative disease course after appendectomy as experimental treatment for patients with therapy refractory moderate to severe ulcerative colitis
Reijntjes, M.(1)*;Heuthorst, L.(1);Stellingwerf, M.(1);d'Haens, G.R.(2);Bemelman, W.A.(1);Buskens, C.J.(1);
(1)Amsterdam University Medical Centers, Surgery, Amsterdam, The Netherlands;(2)Amsterdam University Medical Centers, Gastroenterology, Amsterdam, The Netherlands;
Background
Increasing evidence suggests appendectomy as a potential experimental therapy for ulcerative colitis (UC). A prospective cohort study of laparoscopic appendectomy for treatment of therapy refractory UC showed a clinical response in nearly half of the patients with a substantial proportion of patients in endoscopic remission, after a postoperative follow-up of 3.7 years1. The current study aimed to explore disease course during long-term follow-up in patients undergoing appendectomy for therapy-refractory UC.
Methods
In this monocenter cohort series, all patients with therapy refractory UC referred for (procto)colectomy between 2012-2015 were counselled to undergo laparoscopic appendectomy instead. The primary endpoint was long-term clinical (>3 points decrease in partial mayo score) and endoscopic response (Endoscopic Mayo score ≤1) displayed in individual time lines. Secondary endpoints included duration and loss of clinical and endoscopic response, de-escalation of medication, and failure (medical treatment switch or colectomy).
Results
A total of 25 patients (12 men; median age 41.0 years) underwent appendectomy. The median postoperative follow-up time was 7.5 [IQR 6.4-8.6] years. Clinical response was observed in 60% (15/25) after a median follow-up of 4.0 [IQR 3.0-7.0] months, and was 32% (8/25) at the end of follow-up. Endoscopic response was observed in 48% (12/25) after a median follow-up of 17.5 [IQR 3.3-38.8] months and was 24% (6/25) at the end of follow-up. The median duration of clinical and endoscopic response was 80.0 [20.0-93.0] an 45.5 [21.8-56.8] months, respectively. Six (24%) patients de-escalated medication during follow-up, five of which without subsequent failure. Seventeen (68%) patients failed during postoperative follow-up after appendectomy, of which nine patients (36%) required colectomy a median of 5.0 [IQR 2.0-13.5] months after appendectomy.
Figure 1. Disease course after appendectomy per patient. 
Conclusion
During the postoperative course following appendectomy for refractory UC, approximately half of the patients demonstrated long-lasting endoscopic response, more than half demonstrated long-lasting clinical response, and one third underwent colectomy.
1Stellingwerf ME, Sahami S, Winter DC, Martin ST, D'Haens GR, Cullen G, Doherty GA, Mulcahy H, Bemelman WA, Buskens CJ. Prospective cohort study of appendicectomy for treatment of therapy-refractory ulcerative colitis. Br J Surg. 2019 Nov;106(12):1697-1704.