形似腎水腫之大型動靜脈瘻管，若不慎穿刺可能造成嚴重出血
胡哲源1，陳億聲2，林永明1
1成大醫院泌尿部，2安南醫院泌尿部
A huge intra-renal arteriovenous fistula mimicking hydronephrosis or cyst which capacitate severe bleeding if needle puncture was performed without caution
Che-Yuan Hu1, Yi-Sheng Chen2, Yung-Ming Lin1
1Department of Urology, National Cheng Kung University Hospital
2Department of Urology, Tainan Municipal An-Nan Hospital
Introduction:
Renal arteriovenous fistulas (AVFs) are uncommon. The estimated rate of renal AVFs in large autopsy series is less than 1 case per 30,000 patients [1]. They are often asymptomatic and found by image studies in health checkup, incidentally. Endovascular techniques have been described in previous literatures for AVFs as a first-line therapy and achieved excellent successful rates with the advantages of conservation and preservation of nephrons compared to partial or total nephrectomy. We reported a case of woman with an idiopathic asymptomatic giant renal AVF (7.4cm in diameter) dealt with transarterial embolization successfully.
Case report:
A 46-year-old female had no clinical history and received health checkup. Renal ultrasonography suggested right hydronephrosis (fig1A). But laboratory evaluation including serum creatinine (1mg/dl), BUN (16mg/dl), serum electrolyte and urine analysis were all within normal range. Intravenous pyelography revealed a well-defined cystic lesion compressing right renal pelvis and upper pole calyces (fig2). Color Doppler ultrasonography revealed intra-renal cystic lesion with 7 cm in diameter and bidirectional blood flow (fig1B). Computed tomography showed lobulated masses occupying in right renal pelvis with calyceal and extra-renal extension. Vein-like enhancement was noted following contrast injection in the nephrographic phase (fig3ABC). Magnetic resonance imaging with contrast showed the vascular lesion had the properties of early opacification in arterial phase and persistent enhancement in venous phase. Reconstructed magnetic resonance angiography revealed a right renal loculated vascular lesion with fistulous communication to the end of right renal artery (fig3D). Trans-arterial angiography demonstrated a notably dilated vascular structure with a length of 7.4cm. A feeding artery measured 0.7cm in width and 1.5cm in length was originated proximal to the bifurcation of segmental artery and ended with a palm-like vascular lesion. The high flow within the renal artery emptied into the renal vein via the saccular lesion (fig4ABC). Post-embolization arteriography revealed complete obliteration of the AVF(fig 4D). After transarterial embolization of the arteriovenous fistula, bi-directional blood flow was replaced by thrombus formation(fig 1C). The renal ultrasonography 4 months after the procedure revealed the lesion shrank (3.1cm in length).