US autopsies help doctors understand COVID-19

  By Theresa Pablos, AuntMinnie staff writer

 June 3, 2020 -- A hospital in São Paulo used a portable ultrasound machine to perform autopsies on 10 patients with fatal cases of COVID-19. The authors described the modality's benefits for studying the effects of the disease caused by the novel coronavirus in a paper published on May 22 in Histopathology.

Using a technique called ultrasound-based minimally invasive autopsies (MIA-US), an ultrasound examiner and technologist took tissue samples from the most affected parts of each patient's organs. The findings confirmed that COVID-19 affects multiple organs and tissues, including the kidneys, spleen, lymph nodes, brain, testicles, and skin.

The ultrasound team also wore head-to-toe personal protective equipment, including two aprons, rubber boots, plastic sleeves, three glove layers, a rubber cap, an N95 mask, a surgical mask, and eye protection.

During the autopsies, the examiner and technologist used a portable ultrasound machine with multifrequency broadband transduces and standard image quality. They scanned patients' organs to identify the most-affected locations, then cut 10-cm openings at the appropriate locations to take ultrasound-guided tissue samples from the lung, liver, kidneys, spleen, and heart. They also took unguided samples from the quadriceps, skin, and brain.

The samples revealed significant lung findings, including exudative and/or proliferative diffuse alveolar damage. The authors also found severe alveolar epithelial changes, which they described as more intense and prevalent than findings for other respiratory viruses.

Many but not all findings outside of the lungs could be attributed to the comorbidities of the patients or to septic shock, the authors noted. For instance, eight patients had fibrinous thrombi in alveolar arterioles and a high density of alveolar megakaryocytes, which the authors believed could be evidence of a hypercoagulative state in severely ill patients. The researchers also found cases with superficial perivascular dermatitis, myositis, orchitis, and myocarditis.

Abdominal imaging reveals bowel injuries in COVID-19 patients

Matt O'Connor | May 12, 2020 | Advanced Visualization

https://www.healthimaging.com/topics/advanced-visualization/imaging-bowel-injuries-covid-19?utm_source=newsletter&utm_medium=hi_monthly

A number of studies have shown how COVID-19 can impact a patient’s lungs, but new research suggests individuals may experience bowel abnormalities as well.

Boston-area physicians retrospectively looked at more than 400 patients admitted to a single center to reach their conclusions, published May 11 in Radiology. They found that abnormalities were most commonly seen in sicker patients with the coronavirus who were also admitted to the intensive care unit.

... "abdominal manifestations” in those who are infected, said study author Rajesh Bhayana, MD, abdominal imaging fellow at Massachusetts General Hospital’s Department of Radiology.

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

As part of their study, Bhayana et al. included patients who tested positive for severe acute respiratory syndrome coronavirus between March 27 and April 10. With an average age of 57 years, 17% of individuals had cross-sectional abdominal imaging, which included 44 ultrasounds, 42 CT scans and one MRI.

In total, 31% of CTs showed bowel abnormalities, which represented 3.2% of all patients involved in the study. Findings included thickening and ischemia-related discoveries such as pneumatosis (gas in the bowel wall) and portal venous gas. In two individuals who had bowel resection, the team found ischemia with patchy necrosis, and both had injuries that suggested bowel ischemia may be caused by small blood clots.

There are a number of potential explanations for this laundry-list of findings, the authors noted, including direct viral infection, small vessel thrombosis, or nonocclusive mesenteric ischemia. But one thing is for sure: More studies are required to determine if SARS-CoV-2 plays a direct role in bowel or vascular injury in those with COVID-19.