A case of non-traumatic rectus sheath hematoma in a post-kidney transplant patient undergoing catheter embolization during anticoagulation treatment for atrial fibrillation.

A 65-year-old man, a post living donor kidney transplant patient, was admitted to the intensive care unit (ICU) with a severe bacterial infection. He also tested positive for coronavirus disease and had a cough. On admission, heparin was administered for atrial fibrillation. On the third day of hospitalization, his general condition had recovered, and he was discharged from the ICU to the general ward. On the fourth day of hospitalization, he experienced abdominal pain, and a hard mass was palpated in the left lower abdomen. On the fifth day of hospitalization, contrast-enhanced computed tomography showed an extensive rectus sheath hematoma (RSH) extending from the left lower abdominal wall to the left side of the bladder, with extravasation from a small branch of the left inferior epigastric artery. Heparin was discontinued, and transcatheter arterial embolization was performed to control the bleeding. RSH is a rare disease, and cases of extensive hematoma in post-kidney transplant patients occur even less frequently. Patients taking anticoagulants and those with chronic kidney disease are at high risk for RSH, so physicians should be cognizant of this disease when these patients develop abdominal pain.