Narrow-band imaging for scar (NBI-SCAR) classification: from conception to multicenter validation.

BACKGROUND AND AIMS: Surveillance post-endoscopic resection (ER) currently warrants biopsy samples from the resection site scar in most cases, although clinical practice is variable. A classification with standard criteria for scars has not yet been established. We aimed to create and validate a novel classification for post-ER scars by using specific criteria based on advanced imaging. METHODS: Key endoscopic features for scars with and without recurrence were (1) dark brown color, elongated/branched pit pattern, and dense capillary pattern and (2) whitish, pale appearance, round/slightly large pits, and irregular sparse vessels. Scars were first assessed with high-definition white-light endoscopy (HD-WLE) followed by interrogation with narrow-band imaging (NBI). Scars with at least 2 concordant characteristics were diagnosed with "high confidence" for NBI for scar (NBI-SCAR) classification. The final endoscopic predictions were correlated with histopathology. The primary outcome was the difference in sensitivity between NBI-SCAR and HD-WLE predictions. Secondary outcomes included the validation of our findings in 6 different endoscopy settings (Australia, United States, Japan, Brazil, Singapore, and Malaysia). The validation took place in 2 sessions separated by 2 to 3 weeks, each with 10 one-minute videos of post-ER scars on underwater NBI with dual focus. Inter-rater and intrarater reliability were calculated with Fleiss' free-marginal kappa and Bennett et al. S score, respectively. RESULTS: One hundred scars from 82 patients were included. Ninety-five scars were accurately predicted with high confidence by NBI-SCAR in the exploratory phase. NBI-SCAR sensitivity was significantly higher compared with HD-WLE (100% vs 73.7%, P < .05). In the validation phase, similar results were found for endoscopists who routinely perform colonoscopies and use NBI (sensitivity of 96.4%). The inter-rater and intrarater reliability throughout all centers were, respectively, substantial (κ = .61) and moderate (average S = .52) for this subset. CONCLUSIONS: NBI-SCAR has a high sensitivity and negative predictive value for excluding recurrence for endoscopists experienced in colonoscopy and NBI. In this setting, this approach may help to accurately evaluate or resect scars and potentially mitigate the burden of unnecessary biopsy samples.

Bile cast syndrome: Diagnosis and management, a case series.

Background and study aims Bile cast syndrome (BCS) is a complication of orthotopic liver transplantation (OLT). It occurs in 4 % to 18 % of OLT recipients and can present as cholangitis and graft damage or loss. Twenty-two percent of patients with BCS require repeat OLT. The diagnosis and management of BCS can be challenging. Our aim is to share our experience with BCS and to briefly review the diagnosis and management of the condition.

Ipilimumab as a Cause of Severe Pan-Colitis and Colonic Perforation.

Ipilimumab is a human monoclonal antibody that functions as a cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitor that is used to treat malignant melanoma. Due to ipilimumab's removal of immune regulation, specifically through the inactivation of CTLA-4, it is commonly associated with inflammatory and autoimmune events. Gastrointestinal (GI) related immune-related adverse events such as diarrhea occur in 29% of patients with 7.6% of patients specifically suffering from colitis. We describe a case of colonic perforation with ipilimumab use. Our goal is to raise awareness and alert practicing gastroenterologists of this particular adverse effect.​ A 74-year-old male patient presented to the emergency department with complaints of hematochezia, abdominal pain and decreased appetite. The patient's past medical history included desmoplastic BRAF mutation negative melanoma with metastatic disease to the face, liver, and trigeminal nerve. He underwent his last treatment of ipilimumab three weeks prior to presentation. In total, the patient received four doses of 3 mg/kg of ipilimumab every three weeks. Since the initiation of ipilimumab, he reported diarrhea as its adverse effect, which was treated with tapering doses of prednisone one month at a time. Colonoscopy revealed mucosal ulceration and erosion in the rectum, sigmoid colon, and remaining descending colon up to the splenic flexure and cecum. After the colonoscopy, the patient became tachycardic, hypotensive and complained of sudden abdominal pain. A computed tomographic (CT) scan of the abdomen showed free intraperitoneal air. He was immediately taken to the operating room (OR) for an emergent laparotomy. In the operating room, perforations were noted at the splenic flexure and the cecum with large amounts of succus spilling from the perforations. The majority of the large bowel appeared cyanotic and dusky; consequently, a sub-total colectomy with terminal ileostomy was performed. After the procedure, the patient was started on antibiotics for severe peritonitis and admitted to the intensive care unit (ICU) with septic shock. His clinical status continued to deteriorate due to acute respiratory failure, nosocomial pneumonia, severe protein calorie malnutrition and coagulopathy from disseminated intravascular coagulation (DIC). The patient did not recover from his illness and died a few days later. It is imperative that physicians caring for patients receiving treatment with CTLA-4 inhibitors frequently monitor for and promptly treat possible immune-related adverse effects. For patients with ipilimumab-related colitis, prompt identification of symptoms and early treatment with steroids are crucial in preventing harmful or possibly fatal immune-related adverse events. Gastroenterologists should be wary of this adverse side effect in this high-risk population when performing colonoscopy and take necessary precautions.