[Background and Purpose] When measuring blood flow volume of the brachial artery, values may differ depending on measurement sites if the artery meanders. In this study, we aimed to verify the accuracy of flow volume measurement by echo and appropriate measurement sites for tortuous vessels. [Methods] The accuracy of flow volume measurement was verified by circulating a specified flow rate of pseudo-blood through a simulated circuit using an arterial pump and measuring the flow volume in a simulated straight vessel. In addition, flow volume was measured at multiple locations in a meandering simulated blood vessel model to verify the accuracy of each measurement site. Flow volume was also compared with time-averaged flow velocity (TAV) and time-averaged maximum flow velocity (TAMV). [Results] The blood flow volume calculated by TAV was underestimated immediately after passing through the meander, and became closer to the specified blood flow volume on moving away from the meander. [Conclusion] TAV was shown to be more accurate than TAMV for blood flow volume measurement. In addition, when measuring blood flow volume in meandering vessels, it is preferable to measure blood flow at a site away from any meandering passage.

Based on the 2019 and 2020 data listed in the WADDA system of the Japanese Society for Dialysis Therapy, the age-adjusted expected number of patients with dialysis was calculated by multiplying the national ratio of dialysis patients by age group by the population by age group in each prefecture. SIR by primary disease was calculated for each prefecture, using the expected number of incident dialysis patients as the denominator and the value obtained by correcting the actual number of such patients in each prefecture by the nationwide SIR as the numerator. There was a negative correlation between SIR of unknown primary disease and nephrosclerosis, and a weak negative correlation between unknown primary disease and diabetic nephropathy, and between unknown primary disease and chronic glomerulonephritis (p＜0.01, p＜0.05, and p＜0.05, respectively). It is necessary to diagnose the primary disease on dialysis, keeping in mind that nephrosclerosis, chronic glomerulonephritis, and diabetic nephropathy tend to be rare in prefectures where there are many dialysis patients with unknown primary disease.

We report a case of MPO-ANCA-positive rapidly progressive glomerulonephritis (RPGN) involving an elderly male with poorly controlled type 2 diabetes and interstitial pneumonia. Pathological findings on renal biopsy showed crescentic glomerulonephritis associated with post-infectious glomerular nephritis. Although induction therapy with prednisolone (PSL) and rituximab (RTX) for remission was performed, the renal function did not improve, and maintenance hemodialysis was initiated. Subsequently, in the absence of serious infections during maintenance therapy, steroid treatment was discontinued, with evidence of recovery of the residual renal function. After 11 months of RTX maintenance treatment, the patient was able to discontinue hemodialysis. Even with ANCA-associated vasculitis with RPGN in elderly patients with multiple comorbidities, in cases showing signs of a good renal prognosis, it may be possible to discontinue hemodialysis by continuing RTX therapy with appropriate infection prevention.