Successful management of renal abscess secondary to diabetes mellitus with surgical treatment and hyperbaric oxygen therapy.

Renal abscess (RA) is a collection of infective fluid in or around the renal parenchyma. It typically occurs in immunocompromised patients, including those with diabetes mellitus (DM), poor nutritional status, or steroid administration. We herein report a case of RA associated with DM in which hyperbaric oxygen (HBO₂) therapy greatly contributed to the resolution of this disease. The patient was an 85-year-old man with poorly controlled type 2 DM. Contrast-enhanced computed tomography for postoperative follow-up of appendiceal cancer showed a mass lesion with poor contrast enhancement extending from the upper pole of the left kidney to the dorsal side. Therefore, a diagnosis of RA was established. The lesion was percutaneously punctured, and a drainage tube was placed. Antibiotics following sensitivity testing were administered. The catheter was removed six days after its placement. However, pus discharge continued from the catheter removal site, with persistent redness around the wound. Therefore, a lumbotomy incision for abscess drainage was performed on the 49th day. However, the pus discharge persisted, and we decided to perform HBO₂ therapy, expecting decreases in bacterial proliferation, reduction in local edema, and improvement of host defense. HBO₂ therapy for 90 min at two atmospheres absolute was performed ten times. The amount of pus discharge decreased, and redness improved from the fifth day after HBO₂ therapy. One month after starting HBO₂ therapy, the wound was closed, and the pus discharge resolved completely. Four years have passed since the HBO₂ therapy, and there have been no symptomatic or imaging relapses of RA.