Andrew Liman, MD

All Publications

• Pancreatitis Risk Genes Play a Major Role in Pediatric Pancreatitis: Insights From INSPPIRE. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Abu-El-Haija, M., Zhang, W., Wang, F., Cress, G., Dawson, B., Su, X., Thompson, T., Kotha, N., Chugh, A., Cohen, R. Z., Downs, E. M., Fishman, D. S., Freeman, A. J., Gariepy, C. E., Giefer, M. J., Gonska, T. Y., Greer, P., Grover, A. S., Liman, A. Y., Lindblad, D., Liu, Q. Y., Maqbool, A., Mark, J. A., McFerron, B. A., Mehta, M. S., Morinville, V. D., Ng, K., Noel, R. A., Ooi, C. Y., Perito, E. R., Wilschanski, M., Zheng, Y., Yuan, Y., Whitcomb, D. C., Uc, A., Lowe, M. 2026

  Abstract

  Clinical data show that genetic variants are significant risk factors for acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). To expand understanding of the role of genetics in ARP and CP, high-throughput next-generation sequencing of 14 genes was completed in a multi-center pediatric cohort.A cross-sectional study involving 944 pediatric ARP or CP subjects was conducted. CASR, CEL, CFTR, CLDN2, CPA1, CTRC, GGT1, PRSS1, PRSS2, PRSS3, SBDS, SLC26A9, SPINK1, and UBR1 were sequenced. The frequencies of identified variants were compared with frequencies in the gnomAD database. Group differences were calculated by odd ratios (OR), relative risks (RR), and one-tailed Fisher's exact test with false discovery rate (FDR) adjusted p-values.A total of 120 variants, including 79 never previously reported to be associated with pancreatitis, had an increased odd, with OR>1, (FDR≤0.01) compared with gnomAD. Of these, 38 focused variants found in CFTR (10 variants), PRSS1 (6), CTRC (6), SPINK1 (5), PRSS3 (3), GGT1 (3), CASR (2), CPA1 (2), and PRSS2 (1) were included for further analysis. Seventy-four percent of children with ARP or CP carried at least one genetic risk variant. In the ARP group, CASR (p=0.005) and CPA1 (p<0.001) contained the most prevalent variants. In CP, CTRC (p=0.012) and PRSS1 (p<0.001) variants were most common. The presence of any genetic risk variant was associated with faster disease progression from AP to CP compared to none (p=0.014). Variants in PRSS1, CTRC and SPINK1 significantly increased progression to CP.Our findings highlight the importance of assessing genetic risk variants in children with pancreatitis.

  View details for DOI 10.1016/j.cgh.2026.06.004

  View details for PubMedID 42303027

• Cold Snare Polypectomy in Pediatric Polyposis: A Multicenter Experience. Children (Basel, Switzerland) Friesen, H. J., Attard, T. M., Liman, A. Y., Yasui, O. W., Walsh, C. M., Gugig, R., Barakat, M. T. 2025; 12 (3)

  Abstract

  Background: Cold snare polypectomy (CSP) is a well-established and recommended technique in adult gastroenterology for the safe, efficient and complete removal of nonpedunculated lesions up to 10 mm, with piecemeal excision possible for larger lesions. However, the application of CSP in pediatric patients remains underexplored. This study summarizes a multicenter experience of CSP in pediatric polyposis patients, focusing on safety, efficacy and clinical outcomes. Methods: This retrospective study was conducted at two pediatric tertiary centers, encompassing patients aged 1 to 21 years with polyposis who underwent colonoscopy with CSP and hot snare polypectomy (HSP) between January 2022 and January 2023. Patient demographics, procedure characteristics, polyp details and clinical outcomes were analyzed. Results: A total of 477 CSPs were performed in 63 colonoscopies. Satisfactory bowel preparation was noted in 79% of procedures, with a pooled mean procedure duration of 52 min and cecal intubation achieved in 98%. Polyps resected by CSP ranged from 3 to 70 mm in size and were predominantly left-sided. Tissue retrieval was complete in 94% of cases and partial in 5%. Mild intraprocedural bleeding occurred in 25% of CSP cases, requiring endoclip placement in 19%, with no post-procedural bleeding or significant complications observed. Comparatively, CSP demonstrated favorable bleeding rates relative to HSP. At two-week follow-up, four patients required emergency evaluation for unrelated complaints, but with no adverse events attributed to CSP. Conclusions: CSP is a safe and effective technique for the removal of sessile polyps in pediatric patients with polyposis. Mild intraprocedural bleeding, when observed, was effectively managed with standard hemostatic techniques. These findings support the potential of CSP as a preferred modality for sessile polyp removal in pediatric patients, though further research is warranted to define its role across broader pediatric populations and practice settings.

  View details for DOI 10.3390/children12030291

  View details for PubMedID 40150574

• Magnetic endoscopic imaging in pediatric colonoscopy: A positive impact on procedure completion rate and procedure times. Journal of pediatric gastroenterology and nutrition Liman, A., Lal, R., Yasui, O. W., Gugig, R., Barakat, M. T. 2025

  Abstract

  To assess the impact of magnetic endoscopic imaging (MEI) on pediatric colonoscopy.We analyzed demographics, procedure completion, procedure times, complications, and whether or not MEI was used for all colonoscopies between April 27, 2023, and January 18, 2024. MEI was available for every case but used at the endoscopist's discretion. Attendings were surveyed on the frequency and duration of interventions during fellow-performed colonoscopies.We analyzed 310 colonoscopies, 113 (36%) of which used MEI. The average patient age was 13.8 years (range 5 months to 23 years). For the aggregate sample and attending-performed cases, there were fewer males in the groups that used MEI (p < 0.01). There were no other statistically significant differences in demographics or procedure indication when MEI was used. Terminal ileum (TI) intubation rate was higher when MEI was used in the aggregate sample (p = 0.02) and for fellow-performed cases (p = 0.04). TI intubation times and total procedure times were quicker when MEI was used in the aggregate sample and in both strata of attending-performed cases and fellow-performed cases (p < 0.001). One complication was reported in an attending-performed case that did not use MEI. Of the 145 fellow-performed procedures, 98 (68%) had completed surveys, 36 (36%) of which used MEI. There was no statistically significant difference in the number (p = 0.89) or duration (p = 0.96) of attending interventions when MEI was used.MEI use was associated with higher TI intubation rates, faster TI intubation, and shorter total procedure times. MEI may be a valuable adjunctive tool for pediatric endoscopists.

  View details for DOI 10.1002/jpn3.70011

  View details for PubMedID 39968857

• MINIMIZING DUODENOSCOPE-TRANSMITTED INFECTION COMES AT A COST: DUODENOSCOPES WITH SINGLE-USE END CAPS ASSOCIATED WITH HIGHER ADVERSE EVENT RATES IN PEDIATRIC ERCPS Barakat, M., Liman, A., Gugig, R. MOSBY-ELSEVIER. 2024: AB1087

  View details for Web of Science ID 001278323004209

• Initial Experience with Duodenoscopes with Single-Use End Caps in Pediatric Endoscopic Retrograde Cholangiopancreatography: Infection Prevention Comes at a Cost. Gastrointestinal endoscopy Barakat, M. T., Liman, A., Gugig, R. 2024

  Abstract

  BACKGROUND AND AIMS: Duodenoscopes with single-use end caps were introduced to minimize infection risk, but are unstudied in pediatrics.METHODS: We collected clinical data and endoscopists' evaluations of duodenoscopes with single-use end caps versus reusable duodenoscopes over 18 months.RESULTS: A total of 106 ERCPs were performed for patients aged 1-18 (mean 14.2) years. Forty-six involved single-use end caps, with 9 requiring crossover to reusable duodenoscopes. ERCPs involving single-use end caps resulted in more instances of mucosal trauma (10 vs 0, p<0.05) and post-ERCP pancreatitis (4 vs 1, p<0.05), and accounted for 8 of 9 ERCPs requiring advanced cannulation techniques. No post-ERCP infections occurred. Reported challenges included single-use end cap stiffness and difficulty with their alignment for cannulation.CONCLUSIONS: We report difficulty with advancement, greater reliance on advanced cannulation techniques, and higher rates of PEP when using duodenoscopes with single-use end caps in pediatric ERCP. This area warrants further study.

  View details for DOI 10.1016/j.gie.2024.03.009

  View details for PubMedID 38462055

• Pediatric ERCP: Evolving into an Outpatient Procedure. Digestive diseases and sciences Barakat, M. T., Liman, A. Y., Gugig, R. 2024

  Abstract

  While most adult ERCPs are performed on an outpatient basis, pediatric ERCPs are typically performed on an inpatient basis, or with ERCP followed by at least one night inpatient admission. We have begun performing a substantial proportion of our pediatric ERCPs on an outpatient basis, using our clinical judgment to guide the decision process. In the present study, we compare patient characteristics, indications, and adverse events associated with outpatient vs. inpatient ERCP.Using our endoscopy database, we identified patients 18 years of age and under who underwent ERCP from 2019 to 2021. Demographics, hospitalization status, indications, findings, interventions, as well as available adverse event and clinical outcomes data were analyzed.147 ERCP procedures were performed during the study period by one of two interventional endoscopists. A subset of 51 (34.7%) patients underwent outpatient ERCP. Comparison of the two groups (outpatient vs. inpatient ERCP) was notable for no statistically significant difference in patient age, range of indications, or proportion of index vs. subsequent ERCP. Overall rates of ERCP-associated adverse events were low and there was no statistically significant difference between adverse events in patients who underwent outpatient vs. inpatient ERCP.We analyzed outpatient and inpatient pediatric ERCP patient demographics and ERCP characteristics to identify factors that guide decision to determine whether pediatric ERCPs are performed on an outpatient vs. inpatient basis. There was no significant difference in adverse events associated with outpatient vs. inpatient pediatric ERCPs, attesting to the safety of outpatient ERCP for this subset of patients in the studied context. This is an area worthy of future prospective and multi-center study.

  View details for DOI 10.1007/s10620-024-08325-9

  View details for PubMedID 38418682

  View details for PubMedCentralID 1412491

• Preoperative esophagogastroduodenoscopy in pediatric bariatric surgery: A summary of the literature Journal of Pediatric Gastroenterology and Nutrition Liman, A., Koh, L., Barakat, M., Abu El Haija, M. 2024

  View details for DOI 10.1002/jpr3.12095

• ENDOSCOPIC ULTRASOUND-PANCREATIC RENDEZVOUS CAN BE SAFELY AND EFFECTIVELY PERFORMED IN PEDIATRIC PATIENTS WHEN PANCREATIC INTERVENTION IS NOT POSSIBLE WITH STANDARD ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY Barakat, M., Liman, A., Gugig, R. MOSBY-ELSEVIER. 2023: AB1187

  View details for Web of Science ID 001038022802580