About

Christopher Ko, M.D., MA, is an Assistant Clinical Professor at the University of Utah School of Medicine in Salt Lake City. He received his medical degree from Boston University School of Medicine and completed his Internal Medicine Residency at the University of Southern California/LAC+USC. Dr. Ko continued with his Gastrointestinal fellowship at the University of Southern California/LAC+USC, where he served as Chief GI Fellow during the last year of his fellowship. He then completed his Advanced Endoscopy Fellowship at the University of Michigan. Working primarily at the University of Utah School of Medicine’s Huntsman Cancer Institute and University of Utah Main Hospital, Dr. Ko’s main focuses are on the diagnosis and management of patients with gastrointestinal cancers and complex gastrointestinal diseases, with an emphasis on therapeutic endoscopy. He has a particular interest in complex therapeutic endoscopy, advanced endoscopic imaging, and multi-disciplinary management of complex diseases.

Research topics

• Medicine
• Internal medicine
• Surgery
• Cancer research
• Pathology
• Anesthesia
• Immunology
• Biology
• Radiology

Selected publications

• S6489 Early Buried Bumper Syndrome: A Targeted Approach to Salvage a Recent PEG Site and Restore Enteral Access

  The American Journal of Gastroenterology · 2025-10-01

  article

  Introduction: Buried bumper syndrome (BBS) is an uncommon but serious complication of percutaneous endoscopic gastrostomy (PEG) tube placement, in which the internal bumper migrates into the gastric wall. Risk factors include excessive bumper tension, malnutrition, and impaired wound healing. Clinicians should maintain a high index of suspicion in patients presenting with persistent or worsening abdominal pain after PEG placement. Imaging and endoscopic evaluation are critical for timely diagnosis and management, which may help prevent complications such as perforation or peritonitis. Case Description/Methods: A 51-year-old woman with a 20 Fr PEG placed 10 days prior presented with persistent and worsening abdominal pain, along with nausea and vomiting. A computed tomography (CT) scan revealed migration of the internal bumper into the gastric muscularis, consistent with early buried bumper syndrome. Esophagogastroduodenoscopy (EGD) confirmed the finding, with the bumper embedded within the gastric wall. The gastrostomy tract was wide measuring 10-12 mm in diameter with ulceration inside the tract, allowing the endoscope to pass easily through the fistula. Given her need for ongoing enteral nutrition and the recent timing of PEG placement, the team opted to salvage the existing tract. A guidewire was passed through the PEG to secure access, and the buried tube was gently removed using traction and torsion. A new 20 Fr PEG tube was then placed using a pull technique through the same tract. Due to mucosal oozing after removal of the old PEG tube and the large diameter of the fistulous tract, RADA 16 gel was applied to the fistula for hemostasis and healing, and the gastric side was endoscopically sutured to reduce the fistula diameter to approximately 7 mm. Final endoscopic appearance of the new PEG was satisfactory, and the patient's symptoms improved following the procedure and was able to continue using her PEG tube. Discussion: This case highlights a practical and minimally invasive approach to managing early BBS. BBS should be considered in patients with ongoing pain post-PEG placement, and imaging plus EGD can guide diagnosis and tailor interventions. While re-siting the PEG may be necessary, early identification may allow for preservation of the existing tract. The combination modality of endoscopic suturing and RADA 16 application successfully helped salvage the existing tract in our case. Salvage techniques may be appropriate in selected cases with early presentation and favorable anatomy.

  PublisherDOI

• Correction: Endoluminal radiofrequency ablation with stenting versus stenting alone in patients with malignant biliary obstruction: a meta-analysis of randomized trials

  Endoscopy · 2025-07-28

  erratum
  PublisherDOI

• ENDOSCOPIC ULTRASOUND (EUS)-GUIDED GALLBLADDER DRAINAGE VS EUS-GUIDED BILE DUCT DRAINAGE FOR FIRST LINE THERAPY OF MALIGNANT BILIARY OBSTRUCTION: AN INTERNATIONAL MULTICENTER STUDY

  Gastrointestinal Endoscopy · 2025-05-01

  article
  PublisherDOI

• BOC.01.4 ENDOSCOPIC ULTRASOUND (EUS)-GUIDED GALLBLADDER DRAINAGE VS EUS-GUIDED BILE DUCT DRAINAGE AFTER FAILED ERCP FOR MALIGNANT BILIARY OBSTRUCTION: AN INTERNATIONAL MULTICENTER STUDY

  Digestive and Liver Disease · 2025-04-01

  article
  PublisherDOI

• Natural orifice transluminal endoscopic surgery as salvage therapy for a migrated lumen-apposing metal stent in recurrent cholecystitis

  Gastrointestinal Endoscopy · 2025-06-17

  articleSenior author
  PublisherDOI

• COMPARISON OF ESOPHAGEAL STENT MIGRATION RATES AFTER FIXATION USING CLIPS WITH ANCHOR PRONGS VERSUS OVER-THE-SCOPE CLIPS

  Gastrointestinal Endoscopy · 2025-05-01

  articleSenior author
  PublisherDOI

• Reduced migration of esophageal fully covered self-expandable metal stents affixed with clips with anchor prongs

  iGIE · 2025-01-18 · 2 citations

  articleOpen accessSenior author

  Background and Aims: Fully covered self-expandable metal stents (FCSEMSs) are a common therapeutic treatment for benign and malignant esophageal disorders. Stent migration is a common adverse event of FSCEMSs. We describe clips with anchor prongs (CAPs) as a novel technique to reduce FCSEMS migration. Methods: We retrospectively analyzed 27 patients with FCSEMSs affixed with CAPs and 28 patients without FCSEMS affixation for stent migration as the primary endpoint and used previously published data to determine the relative risk reduction (RRR). Results: = .02). The only adverse event reported in those with (n = 4) or without (n = 14) CAP fixation was postprocedural pain. Conclusions: CAPs may reduce stent migration, providing a novel option for the endoscopist seeking a means of securely attaching esophageal FCSEMSs.

  PublisherOA PDFDOI

• S201 EUS-Guided Choledochoduodenostomy vs ERCP Transpapillary Metal Stenting for Distal Malignant Biliary Obstruction: Outcomes From a Single Center Experience

  The American Journal of Gastroenterology · 2025-10-01

  article

  Introduction: Endoscopic retrograde cholangiopancreatography with metal stenting (ERCP-M) is standard care to treat distal malignant biliary obstruction (dMBO). Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) with a lumen apposing metal stent has emerged as rescue therapy when ERCP-M fails and as a potential alternative first line therapy. Studies show comparable results, but involved endoscopists experienced in EUS biliary drainage (EUS-BD). We review outcomes of EUS-CDS for dMBO at our institution, with minimal prior EUS-BD experience. Methods: Adult patients with dMBO treated by 2 endoscopists (4 EUS-CDS total, prior to study) with ERCP-M or EUS-CDS from 1/1/22 to 7/30/24 were included for retrospective analysis. Demographics, comorbidities, cancer type/extent, clinical success (bilirubin decrease >30% by 1 week or >50% by 30 days), 30-day complication/readmission rates, and biliary reintervention rates were compared between cohorts. One year stent patency (time from index procedure to first reintervention, death, or surgery) was assessed by Kaplan-Meier method with log rank. Predictors of stent dysfunction were evaluated by univariable and multivariable Cox regression. Results: A total of 174 patients were included; 36 EUS-CDS, 138 ERCP-M. EUS-CDS technical success was 97%; 75% (27/36 cases) were performed as first line. Cases were restricted to a bile duct diameter ≥14 mm. Cohort characteristics were similar except for greater bile duct diameter and bilirubin in the EUS-CDS group. Both groups achieved high clinical success; 98% ERCP-M, 100% EUS-CDS. One-year stent patency did not significantly differ between cohorts. There was no difference in time to discharge, 30-day complication/readmission rates, stent occlusion or need for repeat biliary intervention. The most common 30-day complication was cholangitis (n = 3, 75%) after EUS-CDS and pancreatitis (n = 10, 45%) after ERCP-M. On univariable analysis, BMI (for every 10 kg/m2 increase), metastatic disease and prior chemotherapy (hazard ration [HR] 1.52, 2.2, 2.15, respectively) were associated with higher reintervention. BMI and metastatic disease remained significant on multivariable analysis (HR 1.74 and 2.18). There was no difference in reintervention between groups after adjusting for these covariables. Conclusion: Our experience suggests that EUS-CDS, with proper training, is adoptable for therapeutic endoscopists without prior EUS-BD expertise with outcomes comparable to ERCP-M for salvage and first line treatment of dMBO.

  PublisherDOI

• Single-stage EUS-guided gastrogastrostomy secured with clips with anchor prongs to treat massive GI hemorrhage in Roux-en-Y gastric bypass

  Gastrointestinal Endoscopy · 2025-02-28

  articleSenior author
  PublisherDOI

• BOC.04.5 ENDOSCOPIC ULTRASOUND (EUS)-GUIDED GALLBLADDER DRAINAGE VS EUS-GUIDED BILE DUCT DRAINAGE FOR FIRST LINE THERAPY OF MALIGNANT BILIARY OBSTRUCTION: AN INTERNATIONAL MULTICENTER STUDY

  Digestive and Liver Disease · 2025-04-01

  article
  PublisherDOI

Recent grants

• NIH Grant R01NS017954

  NIH · $3.4M · 2007

Frequent coauthors

• Rémy Nicolle

  Inserm

  32 shared

• Richard S. Kwon

  31 shared

• Nina G. Steele

  30 shared

• Nicole Peterson

  29 shared

• Sarah M. Kabala

  29 shared

• Michael Mattea

  29 shared

• Padma Kadiyala

  University of Michigan–Ann Arbor

  29 shared

• Samantha B. Kemp

  29 shared

Education

• M.D.

  Boston University School of Medicine

• Other, Internal Medicine Residency

  University of Southern California/LAC+USC

• Other, Gastrointestinal fellowship

  University of Southern California/LAC+USC

• Other, Advanced Endoscopy Fellowship

  University of Michigan