Sonographic diagnosis of arteriovenous fistula and pseudoaneurysm after biopsy of a transplanted kidney

Abstract

Ultrasonography is useful in assessing the trans~ planted kidney for hydronephrosis and postoperative fluid collections. Percutaneous biopsy, however, re~ mains the definitive method of distinguishing between rejection and other causes of transplant failure. Unfortunately, biopsy procedures are not without complications, including bleeding, infection, and vascular problems such as A V fistula and pseudoaneurysms.t,2 CSDI provides a rapid, sensitive, and noninvasive technique for detecting vascular complications after biopsy of the transplanted kidney.• This report describes a postbiopsy examination in which CSDI diagnosed both an A V fistula and a pseudoaneurysm within the same renal allograft. •Please address all correspondence to Ethan J. Halpern, MD, Department of Radiology, Division of Diagnostic Ultrasound, Jefferson Medical College, 132 South lOth Street, Philadelphia, P A 19107-5244. CASE REPORTA 27 year old man had a percutaneous needle biopsy 2 weeks after receiving a cadaveric renal transplant. The sonographically guided biopsy was performed with no im· mediate complications. The immediate postprocedure sonogram was unremarkable.One week after the procedure the patient developed a fever. A follow-up sonographic examination demonstrated a hypoechoic mass in the lower pole of the transplant kidney at the site of the previous biopsy (Fig. 1).Color Doppler examination demonstrated swirling blood flow within this mass. Spectral doppler detected to-and-fro wave forms characteristic of a pseudoaneurysm (Fig. 2). Further evaluation with CSDI identified two enlarged vessels extending from the mass to the renal hilum (Fig. 2). One of the vessels had an arterial signal with elevated systolic and diastolic velocities. The second demonstrated a venous signal with increased pulsatility relative to the other intrarenal veins. A communication between these two vessels demonstrated high velocity flow with aliasing, representing the site of A V communication. Clinical examination performed after the sonographic study demonstrated a clearly audible bruit over the transplanted kidney.A follow-up scan performed 13 days after the initial discovery of the pseudoaneurysm revealed partial thrombosis of the pseudoaneurysm with continued patency of the A V fistula (Fig. 3). A repeat sonographic study 1 month later demonstrated complete thrombosis of the pseudoaneurysm but continued patency of the AV fistula (Fig. 4).

Renal Artery Embolization

“…Most of the time, they are asymptomatic when small and spontaneously thrombose. 43 However, when they are symptomatic, a patient can present with a pulsatile mass in the pelvis, flank pain, renal dysfunction secondary to compression of artery branches or shunting of blood, or hemorrhage from rupture. Although these lesions can be managed surgically, RAE is preferred if they are amenable to embolization to minimize the loss of normal functioning renal parenchyma (Fig.…”

Renal allograft arteriovenous fistula and large pseudoaneurysm

“…Subsequently in the course of repair processes of the perivascular tissues, they are liquefied and dissolved, leaving a sac continuous with the endluminal space (4). Biopsy‐induced AVFs and pseudoaneurysms are known to be accurately identified by echo‐Doppler imaging, which can detect intrarenal blood flow abnormalities (5, 6), and selective arteriography, which can evaluate size and localization (1, 7). Some authors have suggested conservative management of biopsy‐related renal allograft injury (7, 8).…”

Arteriovenous Fistula and Pseudoaneurysm: Two Important But Rare Complications of Percutaneous Renal Biopsy and Safety of the 16 G Automated Biopsy Needle

“…Biopsy-induced AVF and pseudoaneurysm are known to be correctly identifi ed by CDU imaging, which can distinguish intrarenal blood fl ow abnormalities (36) and by selective arteriography, which can evaluate size and localization (37). Although angiography is known as a gold standard for the diagnosis of postbiopsy AVF and pseudoaneurysm, CDU has been used effectively to detect AVF and pseudoaneurysm after biopsy (26,31,32,(37)(38)(39).…”