ACR Appropriateness Criteria® Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update.

Diverticulosis remains the commonest cause for acute lower gastrointestinal tract bleeding (GIB). Conservative management is initially sufficient for most patients, followed by elective diagnostic tests. However, if acute lower GIB persists, it can be investigated with colonoscopy, CT angiography (CTA), or red blood cell (RBC) scan. Colonoscopy can identify the site and cause of bleeding and provide effective treatment. CTA is a noninvasive diagnostic tool that is better tolerated by patients, can identify actively bleeding site or a potential bleeding lesion in vast majority of patients. RBC scan can identify intermittent bleeding, and with single-photon emission computed tomography, can more accurately localize it to a small segment of bowel. If patients are hemodynamically unstable, CTA and transcatheter arteriography/embolization can be performed. Colonoscopy can also be considered in these patients if rapid bowel preparation is feasible. Transcatheter arteriography has a low rate of major complications; however, targeted transcatheter embolization is only feasible if extravasation is seen, which is more likely in hemodynamically unstable patients. If bleeding site has been previously localized but the intervention by colonoscopy and transcatheter embolization have failed to achieve hemostasis, surgery may be required. Among patients with obscure (nonlocalized) recurrent bleeding, capsule endoscopy and CT enterography can be considered to identify culprit mucosal lesion(s). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Donor-Derived Hepatic Neuroendocrine Tumor: Pause Before Proceeding With Liver Retransplantation.

Gastrointestinal neuroendocrine tumors (NET) are rare but the age-adjusted incidence in the United States has increased, possibly due to improved radiographic and endoscopic detection. In advanced NET, hepatic metastases are common. Orthotopic liver transplant (OLT) is currently considered an acceptable therapy for selected patients with limited hepatic disease or liver metastases where complete resection is thought to have curative intent. The development of NET of donor origin is very uncommon after organ transplant, and it is unclear if the same treatment strategies applied to hepatic NET would also be efficacious after OLT. Here, we describe a unique case of an OLT recipient with a donor-derived NET that was treated with redo OLT as the primary therapy. The donor-derived NET recurred in the recipient's second liver allograft suggesting an extrahepatic reservoir. This case describes the natural history of such a rare event. Here, we highlight the treatment options for hepatic NET and challenge the role of OLT for a donor-derived hepatic NET.

Multivariate analysis of prognostic factors for survival following doxorubicin-eluting bead transarterial chemoembolization for hepatocellular carcinoma.

PURPOSE: To identify prognostic factors for survival in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization with doxorubicin-eluting beads (DEBs). MATERIALS AND METHODS: In a retrospective, single-center analysis, tumor- and patient-related factors were recorded for univariate and multivariate analyses via Kaplan-Meier and Cox regression. Infiltrative HCC phenotype and portal vein invasion (PVI) were correlated, and patients with either or both were classified as having radiographically advanced (RAdv) HCC. The primary endpoint was overall survival, which was calculated from the time of first DEB chemoembolization procedure. RESULTS: A total of 168 patients underwent 248 procedures, of which 215 (86.7%) were outpatient procedures. Mean length of stay was 0.33 days, and 25 patients (10.1%) were readmitted within 30 days. A total of 33 patients underwent liver transplantation and were excluded from survival analyses. A total of 130 had cirrhosis; 62, 50, and 18 had Child class A, B, and C disease, respectively. Forty-one patients had infiltrative HCC phenotype, 28 of whom also had PVI. Multivariate analysis of survival in all patients showed α-fetoprotein (AFP), performance status (PS), RAdv HCC, Child classification, albumin level, and ascites to predict survival. In patients without RAdv HCC, AFP, PS, Child classification, albumin level, and International Normalized Ratio were independent predictors. Increased bilirubin level was not an independent risk factor for death. CONCLUSIONS: Independent prognostic factors in patients with HCC undergoing DEB chemoembolization have been identified. Increased bilirubin level was not an independent risk factor. These data can be used in HCC patient selection and counseling for DEB chemoembolization.

Embolization of hepatocellular carcinoma with drug-eluting beads: doxorubicin tissue concentration and distribution in patient liver explants.

BACKGROUND & AIMS: To follow the local tissue delivery of doxorubicin in HCC explants from patients embolized with drug-eluting beads and to compare it with histologic modifications. METHODS: Six patients with HCC underwent chemoembolization with doxorubicin-eluting beads (caliber 100-300 µm, dose 75-150 mg) followed by liver transplantation at different time points (8 h to 36 days). On sections of the explanted liver, the tissue concentration of doxorubicin was determined radially around bead-occluded vessels with microspectrofluorimetry. The intra/peritumoral location of the beads and the modifications of the surrounding tissue were determined on an adjacent hematein-eosin-saffron-stained section and compared to drug measurements. RESULTS: Doxorubicin was detected in the tissue surrounding the beads at all times of explantation. The drug impregnates an area of at least 1.2 mm in diameter around the occluded vessel. The tissue concentration of drug ranges from 5 µM at 8 h to 0.65 µM at 1 month. In patient transplanted at 8 h, no major tissue modification was observed and we found 42% of the beads occluding intratumoral vessels. Drug concentration was not different around intratumoral and peritumoral occluded vessels. After 9-14 days, necrosis was present around 37% of vessels and at 32-36 days, around 40% of vessels. Necrotic tissue was associated with a deeper penetration and a higher concentration of the drug than non necrotized areas, though statistically significant only at 32-36 days. CONCLUSIONS: Doxorubicin-eluting beads provide a sustained delivery of drug for a period of 1 month and local tissue concentrations above cytotoxic threshold in HCC-bearing livers.