P.F. Lung

Developing a core outcome set for fistulising perianal Crohn’s disease

Objective Lack of standardised outcomes hampers effective analysis and comparison of data when comparing treatments in fistulising perianal Crohn’s disease (pCD). Development of a standardised set of outcomes would resolve these issues. This study provides the definitive core outcome set (COS) for fistulising pCD. Design Candidate outcomes were generated through a systematic review and patient interviews. Consensus was established via a three-round Delphi process using a 9-point Likert scale based on how important they felt it was in determining treatment success culminating in a final consensus meeting. Stakeholders were recruited nationally and grouped into three panels (surgeons and radiologists, gastroenterologists and IBD specialist nurses, and patients). Participants received feedback from their panel (in the second round) and all participants (in the third round) to allow refinement of their scores. Results A total of 295 outcomes were identified from systematic reviews and interviews that were categorised into 92 domains. 187 stakeholders (response rate 78.5%) prioritised 49 outcomes through a three-round Delphi study. The final consensus meeting of 41 experts and patients generated agreement on an eight domain COS. The COS comprised three patient-reported outcome domains (quality of life, incontinence and a combined score of patient priorities) and five clinician-reported outcome domains (perianal disease activity, development of new perianal abscess/sepsis, new/recurrent fistula, unplanned surgery and faecal diversion). Conclusion A fistulising pCD COS has been produced by all key stakeholders. Application of the COS will reduce heterogeneity in outcome reporting, thereby facilitating more meaningful comparisons between treatments, data synthesis and ultimately benefit patient care.

A Systematic Review: The Management and Outcomes of Ileal Pouch Strictures

Background Restorative proctocolectomy with ileal pouch-anal anastomosis removes the diseased tissue in ulcerative colitis but also allows gastrointestinal continuity and stoma-free living. Pouch strictures are a complication with a reported incidence of 5-38%. The three areas where pouch strictures occur are in the pouch inlet, mid-pouch and pouch-anal anastomosis. Aim To undertake a systematic review of the literature and to identify management strategies available for pouch-anal, mid-pouch and pre-pouch ileal strictures and their outcomes. Methods A computer-assisted search of the online bibliographic databases MEDLINE and EMBASE limited to 1966 to February 2016 was performed. Randomized controlled trials, cohort studies, observational studies and case reports were considered. Those where data could not be extracted were excluded. Results Twenty-two articles were considered eligible. Pouch-anal strictures have been initially managed using predominately dilators which include bougie and Hegar dilators with various surgical procedures advocated when initial dilatation fails. Mid-pouch strictures are relatively unstudied with both medical, endoscopic and surgical management reported as successful. Pouch inlet strictures can be safely managed using a combined medical and endoscopic approach. Conclusion The limited evidence available suggests that pouch-anal strictures are best treated in a stepwise fashion with initial treatment to include digital or instrumental dilatation followed by surgical revision or resection. Management of mid-pouch strictures requires a combination of medical, endoscopic and surgical management. Pouch inlet strictures are best managed using a combined medical and endoscopic approach. Future studies should compare different treatment modalities on separate stricture locations to enable an evidenced-based treatment algorithm.

P575 A new tool for the surveillance of Crohn's perianal fistulae

Background: Magnetic Resonance Imaging (MRI) is the tool used to assess response to medical therapy for the treatment of perianal Crohn’s fistulae. Quantifying fistula volumes would be more beneficial than relying on subjective MRI reports. We aim to use computer software and MRI segmentation to design 3D models of fistula tracks and measure baseline and post-biologics treatment fistula volumes. Methods: Ten baseline and post-biologics MRI images of Crohn’s perianal fistulae were randomly selected. Three-Dimensional fistula models were independently created by a surgeon and radiologist • Manual fistula volumes were calculated for each patient and the results compared • Data were obtained on Perianal Disease Activity Index (PDAI) scores, clinical and radiological healing for these patients. Data were analysed using Spearman’s correlation to determine whether a change in fistula volume over a one-year period correlated with a change in PDAI score over the same time period. Fistula volumes and PDAI score were also correlated with degrees of clinical healing. Results: Baseline volumes for the surgeon showed a median of 9766mm3 (IQR 4636, 30980). Post-biologics volumes had a median of 4200mm3 (IQR 2720, 20070). A change in baseline and post-treatment volumes was also observed by the radiologist; the median volume was 9207mm3 (IQR 5132, 21710) for the baseline MRIs and 2872mm3 (IQR 1827, 18830) for the post-treatment ones.

Innovation in the imaging of perianal fistula: a step towards personalised medicine:

Background: Perianal fistula is a topic both hard to understand and to teach. The key to understanding the treatment options and the likely success is deciphering the exact morphology of the tract(s) and the amount of sphincter involved. Our aim was to explore alternative platforms better to understand complex perianal fistulas through three-dimensional (3D) imaging and reconstruction. Methods: Digital imaging and communications in medicine images of spectral attenuated inversion recovery magnetic resonance imaging (MRI) sequences were imported onto validated open-source segmentation software. A specialist consultant gastrointestinal radiologist performed segmentation of the fistula, internal and external sphincter. Segmented files were exported as stereolithography files. Cura (Ultimaker Cura 3.0.4) was used to prepare the files for printing on an Ultimaker 3 Extended 3D printer. Animations were created in collaboration with Touch Surgery™. Results: Three examples of 3D printed models demonstrating complex perianal fistula were created. The anatomical components are displayed in different colours: red: fistula tract; green: external anal sphincter and levator plate; blue: internal anal sphincter and rectum. One of the models was created to be split in half, to display the internal opening and allow complexity in the intersphincteric space to better evaluated. An animation of MRI fistulography of a trans-sphincteric fistula tract with a cephalad extension in the intersphincteric space was also created. Conclusion: MRI is the reference standard for assessment of perianal fistula, defining anatomy and guiding surgery. However, communication of findings between radiologist and surgeon remains challenging. Feasibility of 3D reconstructions of complex perianal fistula is realized, with the potential to improve surgical planning, communication with patients, and augment training.

Acceptability, effectiveness and safety of a Renew® anal insert in patients who have undergone restorative proctocolectomy with ileal pouch-anal anastomosis

Restorative proctocolectomy has gained acceptance in the surgical management of medically refractive ulcerative colitis and cancer prevention in familial adenomatous polyposis. Incontinence following restorative proctocolectomy occurs in up to 25% of patients overnight. The Renew® insert is an inert single‐use device which acts as an anal plug. The aim of this study was to assess the acceptability, effectiveness and safety of the Renew® insert in patients who have undergone restorative proctocolectomy. The device has yet to be assessed in patients who have undergone restorative proctocolectomy.

Review article: pathogenesis of Crohn's perianal fistula-understanding factors impacting on success and failure of treatment strategies

Evidence from groups who have studied fistula aetiology and extrapolation from interventional studies supports a multifactorial hypothesis of Crohns perianal fistula, with several pathophysiological elements that may contribute to fistula formation, persistence and resistance to treatment.

PTU-216 Three-dimensional volume measurements are more accurate than clinical assessment of response to anti-tnf therapy for crohn’s anal fistulae

Introduction The use of anti-TNF therapy for the treatment of fistulising perianal Crohn’s disease relies heavily on clinical and radiological assessments in order to assess response. We have shown that a third of patients sustain radiological remission at 3-years follow-up. It is difficult to predict response based on MRI images as they are difficult to interpret. Having a three-dimensional (3-D) fistula model and being able to quantify the changes in the fistula volume would be more beneficial than relying on complex and subjective MRI reports. We aim to use computer software and MRI segmentation to design 3D models of Crohn’s anal fistulae, measure baseline and 3 years post-biologics treatment fistula volumes and compare with clinical and MRI healing. Method Three-Dimensional fistula models were independently created by the surgeon and radiologist using the previously validated surgical computer software. Thirty-eight patients were selected and volumes were measured at baseline and 3-years post biological therapy. Kappa statistics were used to assess correlation between the healing categories for the three assessment techniques: volume measurements, clinical and MRI healing. Binary logistical regression analysis was used to assess predictors of changes in 3-D anal fistula volumes. Results A change in baseline and post-treatment volumes was observed. The three assessment tools were clinical healing, radiological healing and change in 3-D anal fistula volumes. The agreement between each pair of assessment techniques were measured using Kappa values. There was fair agreement between 3-D volumes and MRI healing (K = 0.34; 95% CI = 0.11, 0.57). Poor agreement was noted between 3-D volumes and clinical healing (K = 0.05; 95% CI = -0.15, 0.25) and the agreement was also poor for clinical and MRI healing (K = 0.10; 95% CI = -0.12, 0.32). On binary logistical regressional analysis, the single independent factor predictive of 3-D volume change was the duration of the disease. An increased duration of disease was associated with a reduced likelihood of an improvement in volumes (OR = 0.57; 95% CI = 0.33, 0.9, p = 0.045). Five-year increase in the duration of disease was associated with two-fold decrease in the odds of improvement. Conclusion MRI volume measurements of 3D Crohn’s fistula models provide an accurate assessment tool. The measurement of perianal fistulae volumes is more is useful than using MRI reports alone as it gives a quantitative measure that can be used to assess the efficacy of therapy. Serial fistula volume measurements should be used for monitoring the response to biological therapy for perianal Crohn’s fistula patients. Disclosure of interest None Declared.