No abstract

Renal artery stenosis (RAS) is the most common correctable cause of hypertension. The current study was undertaken to evaluate the usefulness of color Doppler flow imaging as a screening examination in the detection of significant RAS. Fifty-five kidneys in 30 patients were examined with aortography and color Doppler flow imaging in a double-blind fashion. The peak systolic velocity (PSV) in the renal artery, the renal-aortic ratio (RAR) (ie, the ratio of the PSV in the renal artery to the PSV in the aorta), and the renal artery resistive index were determined and compared with the percentage of stenosis as determined with angiography. Ultrasound (US) criteria used to diagnose RAS were (a) an RAR of 3.5 or greater and/or (b) a renal artery PSV of greater than 100 cm/sec. Doppler tracings were obtained in 25 (69%) of 36 kidneys with a patent single renal artery. RAR and PSV each yielded a sensitivity of 0% in the diagnosis of RAS. Doppler tracings were obtained in three (50%) of six occluded renal arteries. Accessory arteries were present in 13 (24%) of 55 kidneys, but none were visualized with color Doppler flow imaging. The authors conclude that with current technical capability, color duplex US is not an adequate screening method for the detection of RAS.

Contemporary management of upper tract calculi in patients with a urinary diversion is associated with a high recurrence rate, especially among those with recurrent bacteriuria, regardless of whether the patient is initially rendered stone-free. Continued close surveillance and antibiotic prophylaxis seem to be essential in this high risk patient population.

Cyanoacrylate glue is a rapidly polymerizing agent used for vascular embolization. Polymerization occurs when the glue comes into contact with ions in the blood or on the vascular endothelium. Mixing iophendylate with cyanoacrylate causes slowing of polymerization, allowing flow-directed embolization into the nidus of an arteriovenous malformation (AVM) or the central neovascularity of a tumor or hemangioma. The authors attempted to define the relationship between the iophendylate-glue ratio and polymerization time with an in vivo swine model. In this model, glue setup occurred much more rapidly than predicted on the basis of in vitro studies. This appeared to be due to glue polymerizing on the endothelium at vessel bifurcations and at areas of acute angulation or marked vessel narrowing. On the basis of these data, the authors substantially increased the iophendylate-glue ratio in their most recent AVM embolization procedures and achieved nidus occlusion in each case. With use of the authors' guidelines, it is possible to achieve optimal distal flow-directed embolization with cyanoacrylate.

One hundred and five sequential transjugular core liver biopsies (TJLBx) were performed in 101 patients with coagulopathy and/or ascites using the 19-gauge Quick-Core Biopsy (QCB) needle. Two-hundred and seventy-three cores were obtained in 295 passes (92. 5%). One-hundred and two of the 105 procedures (97.1%) led to a histopathologic diagnosis. One of the three nondiagnostic biopsies was done because of severe autolysis of the liver. There was one subcapsular hematoma, one hepatic arteriovenous fistula, and one liver capsular puncture. Two minor neck hematomas occurred. One death was reported (unrelated to the procedure). QCB needle TJLBx is an effective and relatively safe way to obtain core liver samples.