Imaging Reveals Bowel Abnormalities in Patients With COVID-19

May 13, 2020

Patients with coronavirus disease 2019 (COVID-19) can have bowel abnormalities, including ischaemia, according to a study published in the journal Radiology.

Several studies have evaluated the chest imaging findings in COVID-19, which helped improve understanding of how the disease affects the lungs. More recently, reports have documented that gastrointestinal symptoms, liver injury, and vascular findings are common in patients with COVID-19. However, abdominal imaging findings have not yet been widely reported.

The current retrospective study included 412 patients consecutively admitted to a single quaternary care centre from March 27, 2020, to April 10, 2020, who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The cohort included 241 men and 171 women, with an average age of 57 years.

Of the patients, 17% had cross-sectional abdominal imaging, including 44 ultrasounds, 42 CT scans, and 1 MRI. Bowel abnormalities were seen on 31% of CT scans (3.2% of all patients) and were more frequent among patients in the intensive care unit (ICU) versus other in-patients. Bowel findings included thickening and findings of ischaemia such as pneumatosis and portal venous gas. Surgical correlation in 4 patients revealed unusual yellow discoloration of bowel in 3 of the patients, and bowel infarction in 2 patients.

“We found bowel abnormalities on imaging in patients with COVID-19, more commonly in sicker patients who went to the ICU,” said Rajesh Bhayana, MD, Massachusetts General Hospital, Boston, Massachusetts.

In 2 patients who had bowel resection, pathology demonstrated ischaemia with patchy necrosis. Both had fibrin thrombi in submucosal arterioles , suggesting bowel ischaemia in these patients might be caused by these blood clots.

Lung base findings led to a diagnosis of COVID-19 in 1 patient who presented with abdominal symptoms only.

Of right upper quadrant ultrasounds, 87% were performed for liver laboratory findings, and 54% demonstrated a dilated sludge-filled gallbladder suggestive of cholestasis, or a decrease in bile flow.

“Some findings were typical of bowel ischaemia, or dying bowel, and in those who had surgery we saw small vessel clots beside areas of dead bowel,” said Dr. Bhayana. “Patients in the ICU can have bowel ischaemia for other reasons, but we know COVID-19 can lead to clotting and small vessel injury, so bowel might also be affected by this.”

According to the researchers, possible explanations for the spectrum of bowel findings in patients with COVID-19 include direct viral infection, small vessel thrombosis, or nonocclusive mesenteric ischaemia.

The authors added that further studies are required to clarify the cause of bowel findings in patients with COVID-19 and to determine whether SARS-CoV-2 plays a direct role in bowel or vascular injury.

“Our study is preliminary, and more work is needed to understand the cause of bowel findings in these patients,” said Dr. Bhayana.

Reference: https://pubs.rsna.org/doi/10.1148/radiol.2020201908

SOURCE: Radiological Society of North America