エコーガイド下移植腎生検後の合併症における危険因子と移植腎予後に関する検討

抄録

【Objective】 Percutaneous and ultrasound-guided renal allograft biopsy (RAB) is the gold standard procedure with which to evaluate renal allograft dysfunction. Major complications after RAB include hematoma, hematuria, and arteriovenous fistula (AVF) in the graft. Since RAB is a relatively invasive test, we evaluated the risk of complications and subsequent prognosis of the graft.

【Methods】 This was a single center retrospective cohort analysis of 325 RABs carried out on 272 patients between 2013 and 2016. Biopsy was conducted percutaneously and with ultrasound-guidance using an 18G or 16G needle. We compared the medical background of patients with and without RAB complications, with special reference to renal functions after RAB in an AVF group and a non-AVF group.

【Results】 In total, we identified 40 complications (12.3%) in 325 RABs, including 1 hematoma (0.3%), 7 hematuria (2.2%), 30 AVF in 30 patients (9.2%), and 2 deep vein thromboses (DVT; 0.62%). Comparisons of patient backgrounds between those with complications (n=40) and those without (n=232) revealed that there was a significant difference in graft weight (205±55 g versus 177±46 g; p=0.023) and everolimus intake (p=0.047). In one case involving hematoma, a small mass had developed around the graft, which spontaneously disappeared over the course of a few days. Although one case presented macroscopic hematuria, this resolved spontaneously. Serum eGFR levels following biopsy were comparable between the AVF group (n=30) and the non-AVF group (n=242) with no graft loss by AVF. Two patients with symptomatic DVT required re-admission: both had a high BMI (>30). While one case developed pulmonary embolism, both were resolved with anticoagulant therapy.

【Conclusion】 Approximately one in every 10 RAB cases was associated with a complication. Graft weight and everolimus intake were significant risk factors for RAB complications. While AVF was the most frequent complication (9.2%), the subsequent function of the grafts was comparable with that of non-AVF cases. However, a life-threatening complication of pulmonary embolism occurred in one case, probably due to compression around the allograft and bed rest for a few hours after the procedure. Our data suggest that physicians need to consider the formation of thrombosis following RAB, particularly in obese patients.