Role of multidetector computed tomography angiography in non-variceal upper gastrointestinal bleeding: A comprehensive review

Value of multidetector computed tomography angiography in severe non-variceal upper gastrointestinal bleeding: a retrospective study in a referral bleeding unit

BACKGROUND

Non-variceal upper gastrointestinal bleeding is a common gastroenterological emergency associated with significant morbidity and mortality. Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment. As historically played a limited role in the diagnosis of acute non-variceal upper gastrointestinal bleeding, multidetector-row computed tomography angiography is emerging as a promising tool in the diagnosis of non-variceal upper gastrointestinal bleeding, especially for severe cases. However, to date, evidence concerning the role of multidetector-row computed tomography angiography in the non-variceal upper gastrointestinal bleeding diagnosis is still lacking.

AIM

The purpose of this study was to retrospectively investigate the diagnostic performance of emergent multidetector-row computed tomography angiography performed prior to any diagnostic modality or following urgent upper endoscopy to identify the status, the site, and the underlying etiology of severe non-variceal upper gastrointestinal bleeding.

METHODS

Institutional databases were reviewed in order to identify severe acute non-variceal upper gastrointestinal bleeding patients who were admitted to our bleeding unit and were referred for emergent multidetector-row computed tomography angiography prior to any hemostatic treatment (< 3 h) or following (< 3 h) endoscopy, between December 2019 and October 2022. The study aim was to evaluate the diagnostic performance of multidetector-row computed tomography angiography to detect the status, the site, and the etiology of severe non-variceal upper gastrointestinal bleeding with endoscopy, digital subtraction angiography, surgery, pathology, or a combination of them as reference standards.

RESULTS

A total of 68 patients (38 men, median age 69 years [range 25-96]) were enrolled. The overall multidetector-row computed tomography angiography sensitivity, specificity, and accuracy to diagnose bleeding status were 77.8% (95% CI: 65.5-87.3), 40% (95% CI: 5.3-85.3), and 75% (95% CI: 63.0-84.7), respectively. Finally, the overall multidetector-row computed tomography angiography sensitivity to identify the bleeding site and the bleeding etiology were 92.4% (95% CI: 83.2-97.5) and 79% (95% CI: 66.8-88.3), respectively.

CONCLUSION

Although esophagogastroduodenoscopy is the mainstay in the diagnosis and treatment of most non-variceal upper gastrointestinal bleeding cases, multidetector-row computed tomography angiography seems to be a feasible and effective modality in detecting the site, the status, and the etiology of severe acute non-variceal upper gastrointestinal bleeding. It may play a crucial role in the management of selected cases of non-variceal upper gastrointestinal bleeding, especially those clinically severe and/or secondary to rare and extraordinary rare sources, effectively guiding timing and type of treatment. However, further large prospective studies are needed to clarify the role of multidetector-row computed tomography angiography in the diagnostic process of acute non-variceal upper gastrointestinal bleeding.

A Self-Powered Lactate Sensor Based on the Piezoelectric Effect for Assessing Tumor Development

The build-up of lactate in solid tumors stands as a crucial and early occurrence in malignancy development, and the concentration of lactate in the tumor microenvironment may be a more sensitive indicator for analyzing primary tumors. In this study, we designed a self-powered lactate sensor for the rapid analysis of tumor samples, utilizing the coupling between the piezoelectric effect and enzymatic reaction. This lactate sensor is fabricated using a ZnO nanowire array modified with lactate oxidase (LOx). The sensing process does not require an external power source or batteries. The device can directly output electric signals containing lactate concentration information when subjected to external forces. The lactate concentration detection upper limit of the sensor is at least 27 mM, with a limit of detection (LOD) of approximately 1.3 mM and a response time of around 10 s. This study innovatively applied self-powered technology to the in situ detection of the tumor microenvironment and used the results to estimate the growth period of the primary tumor. The availability of this application has been confirmed through biological experiments. Furthermore, the sensor data generated by the device offer valuable insights for evaluating the likelihood of remote tumor metastasis. This study may expand the research scope of self-powered technology in the field of medical diagnosis and offer a novel perspective on cancer diagnosis.

Computed Tomography Angiography and Conventional Angiography for the Diagnosis and Treatment of Non-variceal Gastrointestinal Bleeding at a Tertiary Cancer Center

INTRODUCTION

To evaluate the diagnostic value of computed tomography angiography (CTA) and conventional angiography (CA) and the therapeutic value of transarterial embolization for acute gastrointestinal bleeding in patients with malignancy.

METHODS

A retrospective review of 100 patients who underwent CTA and/or CA for gastrointestinal bleeding at a comprehensive cancer center between the years 2011-2021 was performed. Clinical and patient outcome data were collected and analyzed using Kruskal-Wallis tests for continuous variables and chi-square tests or Fisher's exact tests (whichever is appropriate) for categorical variables in univariate analysis. All tests were two-sided at a significance level of 0.05. Analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC).

RESULTS

Fifty-two percent of our patients underwent CTA alone, 29% underwent CA alone, and 19% underwent both procedures. Overall, CTA was positive in 11.3% (8/71) of patients and CA was positive in 22.9% (11/38) of patients. Of patients who underwent both studies, 52.6% (10/19) were positive for both. ICU admission was associated with CTA and/or CA positivity (p=0.015). Of 48 patients with data for embolization, 50% of patients underwent transarterial embolization for bleeding, 11 patients had identifiable bleeding on CA, and 13 patients underwent prophylactic embolization at the site of suspected bleeding. Rebleeding following embolization was found in 33.3% (8/24) of patients, including six patients who underwent prophylactic embolization and two patients who were treated for visualized bleeding.

CONCLUSION

CTA and CA are two critical studies for patients with GI bleeding and a history of malignancy. Neither alone can effectively exclude an identifiable source of bleeding. In patients with a history of malignancy, transarterial embolization may be an effective treatment of both angiographically visible and occult sources of GI bleeding.