Application of Contrast-Enhanced Ultrasound in the Diagnosis of Gastrointestinal Acute Gvhd - Single Centre Experience

Abstract

Introduction: Acute graft versus host disease (aGVHD) is one of the most common complications after allogeneic stem cell transplant, with gastro-intestinal (gut) involvement being associated with increased morbidity and mortality. The gastrointestinal symptoms are common and therefore pose differential diagnostic challenges. Biopsy with histopathological exam by endoscopy represent the gold standard for the diagnosis of gut aGVHD. In clinical practice, the endoscopy exam, a minimal invasive investigation, is difficult to tolerate by the patient and sometimes risky to perform due to the severe thrombocytopenia. For this reason, there is an urgent need to find some non-invasive diagnostic methods, such as standard ultrasound and contrast-enhanced ultrasound (CEUS), hoping that these investigations will help in the early diagnosis as well as in the follow-up response treatment. Aim: The aim of this study was to present our experience with CEUS in diagnosis of gut aGVHD after allogeneic stem cell transplantation Results: Between January 2019 and March 2022, in Fundeni Clinical Institute, 168 allogeneic stem cell transplants were performed. 20/168 were readmitted into the hospital with non-infectious diarrhea and with suspicion of gut aGVHD. All patients were investigated by classical GI tract ultrasound and CEUS. For 12 patients out of 20 we had histopathological confirmation of gut GVHD and could thus corelate with the CEUS findings. For all patients the bowel wall thickness was increased, and the most affected areas were ileal loops, followed by ileocecal region and ascending colon. The most common feature, contrast agent migration in the intestinal lumen (the penetration of microbubbles in the bowel lumen) was observed in 3/12 patients, but, 9/12 remaining patients performed CEUS after the first dose of treatment with corticotherapy. In conclusion, CEUS represent a noninvasive, simple and viable investigation for gut aGVHD, most valuable probably for ileal localization, where the endoscopic approach is difficult. Therefore, it is important to establish which is the exact period after the onset of symptoms when the microbubbles migrate in the bowel lumen and if this parameter can be used to monitor the response to treatment. Based on these results, we aim to introduce CEUS evaluation as standard investigation for aGVHD and monitor all the patients.