A118 BALLOON-ASSISTED ENTEROSCOPY TIMING INCREASES DIAGNOSTIC YIELD IN PATIENTS WITH OVERT OBSCURE GASTROINTESTINAL BLEEDING: A RETROSPECTIVE STUDY

Background

Obscure gastrointestinal bleeding (OGIB) is defined as bleeding from an unknown etiology despite initial investigations with upper endoscopy and colonoscopy, of which 75-80% is attributed to a small bowel (SB) source. OGIB poses a significant diagnostic and therapeutic challenge, resulting in high morbidity and mortality with increased utilization of health care resources. Balloon-assisted enteroscopy (BAE) is a useful procedure for the evaluation and management of small bowel bleeding, with reported diagnostic and therapeutic rates up to 87% and 80%, respectively.

Purpose

This retrospective study aims to evaluate the diagnostic and therapeutic yields in a large cohort of adult patients presenting with different subtypes of OGIB who have undergone BAE, as well as to assess for association between various patient and disease factors, and clinical outcomes.

Method

We performed a retrospective review of 1057 cases of BAE at a large quaternary referral centre between 2016 to 2021 and 158 OGIB cases were identified. Sex, age, and, preprocedural variables including indication, time from video capsule endoscopy (VCE) to BAE and subclassification of SB bleed were collected. Endoscopic modality, findings, and therapeutic interventions were used to calculate diagnostic and therapeutic yields. The association between the timing of BAE relative to VCE and clinical outcomes including rebleeding rate, diagnostics and therapeutic yields were assessed. Bleeding free-survival was estimated using Kaplan-Meier function. All data analyses were performed with SPSS.

Result(s)

The overall diagnostic yield of BAE was 74%. Patients with active overt bleeding were found to have a statistically significant higher yield compared to those with inactive overt bleeding (94% vs 67%, P= 0.03). The therapeutic yield was 51%, with a significantly higher rate of injection therapy and hemoclip placement in those with active overt bleeding compared to those with inactive overt and occult bleeding (P< 0.001). BAE performed within 72 hours of overt GI bleeding was found to have a statistically significant higher diagnostic yield when compared to procedures performed after 72 hours (94% vs 67%, p =0.05). Univariable analysis revealed higher diagnostic yield in patients requiring transfusion within the past 12 months (P= 0.02) Finally, rebleeding-free survival in all patients at 1 year and 5 years was 98% and 68%, respectively.

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Conclusion(s)

Balloon-assisted enteroscopy continues to be an effective diagnostic and therapeutic modality for the investigation of obscure gastrointestinal bleeding. Our retrospective study shows a higher diagnostic yield in those presenting with active overt GI bleed as well as those who underwent BAE within 72 hours of overt GI bleeding. Furthermore, patients who required transfusion within the past 12 months are more likely to have a positive BAE finding.

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Disclosure of Interest

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A31 OUTCOMES OF PATIENTS UNDERGOING REPEAT VIDEOCAPSULE ENDOSCOPY (VCE) PRESENTING WITH OBSCURE GASTROINTESTINAL BLEEDING (OGIB)

Background

Videocapsule Endoscopy (VCE) as well as balloon-assisted enteroscopy (BAE) are useful tools in the diagnosis and management of obscure gastrointestinal bleeding (OGIB). There is limited data assessing the diagnostic yield of VCE in subjects with OGIB according to different subtypes: 1) obscure overt 2) inactive overt and 3) active overt.

Aims

We evaluated the diagnostic yield and outcomes of patients undergoing a second VCE in OGIB.

Methods

This is a retrospective analysis of all patients who underwent more than one VCE completed at the University of Alberta from January 1, 2015 to August 31, 2021. Demographic and background information was collected including previous endoscopy results, cross-sectional imaging, and subsequent interventions. Patient data was analyzed according to subtype of OGIB at presentation.

Results

During the study period, there were 59 subjects who met inclusion criteria. The indication for VCE was recurrent iron deficiency anemia (IDA), active OGIB, and/or inactive OGIB in 38 subjects. The median time to VCE after initial endoscopic evaluation was 61 days. Median age of cases was 61.5 years and 49% were female.

Initial VCE had clinically significant positive findings in 68% of cases (Table 1). The diagnostic yield was 75%, 56% and 74% in active OGIB, inactive OGIB, and IDA, respectively. Active bleeding or fresh blood was present in 33% of VCEs for active OGIB compared to 11% of inactive OGIB and 13% of subjects with IDA.

At second VCE investigation, there were positive findings in 42% of cases. Findings on second VCE differed from initial VCE in 17 of 38 cases. Findings that changed clinical management were found in 76% of patients after first and second VCE.

BAEs were performed in 20 subjects after VCE, with therapeutics applied in 75%. The most common findings were arteriovenous malformations (AVMs) (65%) and erosions/ulcers (15%).

Conclusions

The diagnostic yield of VCE is high in appropriately selected patients and did not significantly differ in patients with IDA, active, and inactive OGIB. Serial VCE is appropriate for the investigation of suspected recurrent small bowel bleeding when initial workup is nondiagnostic.

Funding Agencies

None

A93 USEFULNESS OF A NOVEL SMARTPHONE APP IN GASTROINTESTINAL ENDOSCOPY TO TRACK PROCEDURE NUMBERS AND THERAPEUTIC INTERVENTIONS

Background

Endoscopy teaching is an integral part of gastroenterology (GI) training. Though the number of completed endoscopic procedures does not equate competency, procedure tracking is useful for monitoring an individual’s learning progress. Currently, procedure tracking is typically done on an informal basis using paper or electronic spreadsheets. These methods are non-standardized and may not be shareable between trainees and their programs.

Endostation is a smartphone app created by the University of Alberta Therapeutic Endoscopy Program to facilitate the tracking of endoscopic procedures. The app allows trainees to record the number of endoscopies and details such as cecal intubation (CI), ERCP cannulation, and therapeutic interventions. Data can be accessed by users via the app and website (www.endostation.ca), allowing for close monitoring of trainees’ learning progress.

Aims

Our primary objective was to evaluate the usefulness of the app for tracking the number of endoscopic procedures and therapeutic interventions. Our secondary objective was to evaluate the acquisition of endoscopy skills based on quality endoscopic parameters such as CI rate and ERCP cannulation rate.

Methods

One therapeutic endoscopy fellow and two GI residents were recruited for the study. Participants were asked to document their procedures over the study period (9-month for therapeutic endoscopy fellow, 12-month for GI residents). Total number of procedures was summed for each trainee. Acquisition of endoscopy skills was tracked by comparing success rates of CI and ERCP cannulation at different points within the study period.

Results

The therapeutic endoscopy fellow recorded 415 cannulation attempts, 209 sphincterotomies, 282 stone extractions, 71 plastic stent placements, and 37 metal stent placements. There was a significant difference in the cannulation success rate when comparing the 1^st trimester and the 3^rd trimester of the study period (68% vs 85%; p= 0.0012) (Fig 1).

The two GI residents respectively recorded 335 and 170 colonoscopies plus 454 and 305 gastroscopies. Resident 1 recorded 58 polypectomies, 9 esophageal variceal banding, and 16 non-variceal hemostasis. Resident 2 recorded 17 polypectomies, 12 esophageal variceal banding, and 9 non-variceal hemostasis. The CI success rate was significantly higher for both residents when comparing the first 4 months of training vs the last 4 months [24% vs 88% for resident 1 (p=0.00001); 15% vs 42% for resident 2 (p= 0.001)] (Fig 1).

Conclusions

The smartphone app (Endostation) was a useful tool for endoscopic procedure tracking. Data from the app was useful in demonstrating improvement in CI rate and ERCP cannulation rate over the study period.

Funding Agencies

None

Systematic review: recurrent autoimmune liver diseases after liver transplantation

BACKGROUND

Autoimmune liver diseases (AILD) constitute the third most common indication for liver transplantation (LT) worldwide. Outcomes post LT are generally good but recurrent disease is frequently observed.

AIMS

To describe the frequency and risk factors associated with recurrent AILD post-LT and provide recommendations to reduce the incidence of recurrence based on levels of evidence.

METHODS

A systematic review was performed for full-text papers published in English-language journals, using the keywords 'autoimmune hepatitis (AIH)', 'primary biliary cholangitis and/or cirrhosis (PBC)', 'primary sclerosing cholangitis (PSC)', 'liver transplantation' and 'recurrent disease'. Management strategies to reduce recurrence after LT were classified according to grade and level of evidence.

RESULTS

Survival rates post-LT are approximately 90% and 70% at 1 and 5 years and recurrent disease occurs in a range of 10-50% of patients with AILD. Recurrent AIH is associated with elevated liver enzymes and IgG before LT, lymphoplasmacytic infiltrates in the explants and lack of steroids after LT (Grade B). Tacrolimus use is associated with increased risk; use of ciclosporin and preventive ursodeoxycholic acid with reduced risk of PBC recurrence (all Grade B). Intact colon, active ulcerative colitis and early cholestasis are associated with recurrent PSC (Grade B).

CONCLUSIONS

Recommendations based on grade A level of evidence are lacking. The need for further study and management includes active immunosuppression before liver transplantation and steroid use after liver transplantation in autoimmune hepatitis; selective immunosuppression with ciclosporin and preventive ursodeoxycholic acid treatment for primary biliary cholangitis; and improved control of inflammatory bowel disease or even colectomy in primary sclerosing cholangitis.

Cyclosporine A protects against primary biliary cirrhosis recurrence after liver transplantation

Primary biliary cirrhosis (PBC) reoccurs in a proportion of patients following liver transplantation (LT). The aims of our study were to evaluate the risk factors associated with PBC recurrence and determine whether recurrent disease constitutes a negative predictor for survival. One hundred and eight patients receiving LT for end-stage PBC were studied. Recurrent disease was diagnosed in 28 patients (26%). Probability of recurrent PBC at 5 years was 13% and 29% at 10 years with an overall incidence of 3.97 cases per 100 patient years. By univariate Cox analysis use of tacrolimus (HR 6.28, 95% CI, 2.44-16.11, p < 0.001) and mycophenolate mofetil (HR 5.21, 95% CI, 1.89-14.33, p = 0.001) were associated with higher risk of recurrence; whereas use of cyclosporine A (CsA) and azathioprine were associated with reduced risk of recurrence (HR 0.13, 95% CI 0.05-0.35, p < 0.001 and HR 0.27, 95% CI 0.11-0.64, p = 0.003, respectively). In the multivariate Cox analysis, only CsA was independently associated with protection against recurrence (HR 0.17, 95% CI 0.06-0.71, p = 0.02). Five-year probability of survival was 83% and 96%, in patients without and with recurrence (log-rank test, p = 0.3). Although PBC transplant recipients receiving CsA have a lower risk of disease recurrence, the development of recurrent PBC did not impact on long-term patient survival.

Reverse transcriptase activity in patients with primary biliary cirrhosis and other autoimmune liver disorders

BACKGROUND

Patients with biliary disease make retroviral antibodies and the Human Betaretrovirus has been characterized in patients with primary biliary cirrhosis.

AIM

To screen patients with autoimmune liver disease for evidence of retroviral infection.

METHODS

Real-time reverse transcriptase polymerase chain reaction was used to detect Human Betaretrovirus, and a reverse transcriptase assay to measure reverse transcriptase activity in plasma.

RESULTS

Using reverse transcriptase polymerase chain reaction, 24% of primary biliary cirrhosis samples were positive for Human Betaretrovirus when compared to 13% with autoimmune hepatitis, 5% of other liver diseases and 3% of the non-liver disease control subjects. Reverse transcriptase activity was found in 73% of patients with autoimmune hepatitis, 42% with primary biliary cirrhosis, 22% of liver patients without viral or autoimmune disease and 7% of subjects without liver disease. In patients with autoimmune liver disease, detection of reverse transcriptase activity was related to higher ALT levels, whereas others stabilized on immunosuppressive therapy either preliver or postliver transplantation were less likely to be reverse transcriptase-positive.

CONCLUSIONS

Most patients with autoimmune hepatitis have detectable reverse transcriptase activity. Investigations will be required to assess whether this represents the expression of endogenous retroviruses and retrotransposable elements in inflamed tissue, or signifies the presence of exogenous retroviral infection.