Ultrasound-guided direct basilic-axillary approach in preoperative venography for hemodialysis access.

PURPOSE: Hemodialysis patients with suspected central vein stenosis or occlusion require venographic assessment before access surgery. Conventional venography may be unsatisfactory because of the limited ability to image central veins via peripheral arm veins that are inadequate or that have been damaged by multiple cannulations. Imaging of the central veins requires high flow contrast injection, which may be unattainable through small peripheral veins. We suggest a simple technique to improve central vein imaging by ultrasound-guided direct puncture of the basilic vein at its entry to the axilla. METHODS: We studied 20 patients in whom upper limb venography via peripheral veins was inadequate for the satisfactory demonstration of central vein anatomy and they underwent direct basilic-axillary vein puncture with Doppler ultrasound guidance. A 4Fr micropuncture catheter was used for manual injection of the contrast agent to image the central veins. RESULTS: All patients had inadequate upper limb venography via peripheral vein cannulation, and stenosis could not be ruled out due to poor visualization of the central veins. In all cases, venography by Doppler ultrasound-guided direct basilic-axillary vein puncture was very easy for both the radiologist and the patient, consistently providing high quality imaging without the need for repeated attempts at cannulation and without the need for infusion pumps. No complications were noted during or after the procedure. CONCLUSIONS: Venography by Doppler ultrasound-guided direct basilic-axillary vein puncture is a simple and rapidly performed technique that improves the visualization of the central veins.

Intra-operative central vein angioplasty during arteriovenous access creation.

Central vein stenosis or occlusion due to prior use of central vein hemodialysis catheters may lead to disabling extremity edema or cause early failure after arteriovenous access construction. Our integrated program for arteriovenous access management enables us to identify these stenoses pre-operatively. We carried out intra-operative angiography and angioplasty during arteriovenous access creation in 3 patients with good immediate and long-term results. Intra-operative endovascular therapy is a new application of peripheral vascular surgery techniques for patients with significant central vein stenosis undergoing access surgery, which exploits the high postoperative flow state to maintain patency after angioplasty. It may also be applicable in situations such as proximal arterial stenosis with anticipated steal syndrome and other conditions that may compromise access patency.

Ultrasound vs CT for the detection of ureteric stones in patients with renal colic.

The aim of our study was to compare the accuracy of non-contrast spiral CT with ultrasound (US) for the diagnosis of ureteral calculi in the evaluation of patients with acute flank pain. 62 consecutive patients with flank pain were examined with both CT and US over a period of 9 months. All patients were prospectively defined as either positive or negative for ureterolithiasis, based on follow-up evaluation. 43 of the 62 patients were confirmed as having ureteral calculi based on stone recovery or urological interventions. US showed 93% sensitivity and 95% specificity in the diagnosis of ureterolithiasis; CT showed 91% and 95%, respectively. Pathology unrelated to urinary stone disease was demonstrated in six patients. Although both modalities were excellent for detecting ureteral stones, consideration of cost and radiation lead us to suggest that US be employed first and CT be reserved for when US is unavailable or non-diagnostic.

Sonographic diagnosis of ureteral tumors.

We present our experience with transabdominal ultrasonographic diagnosis of ureteral tumors. During the years 1989 to 1998, 16 patients were diagnosed as having ureteral tumors. These patients were referred for sonographic examination for evaluation of hematuria (seven patients) or flank pain (four patients) or for follow-up screening in patients who were asymptomatic but at high risk for transitional cell carcinoma because of known past bladder tumor (five patients). Ten of these patients underwent intravenous urography examination, three patients had retrograde pyelography, and 11 patients underwent CT scanning. Ultrasonography revealed the ureteral tumors in all 16 patients, which appeared as hypoechoic intraluminal soft tissue. Three tumors were localized in the upper ureter, four in the middle ureter, and nine in the distal ureter. The degree of ureterohydronephrosis was minimal (two cases), mild (five cases), moderate (eight cases), or severe (one case). Eleven tumors caused local widening of the ureteral diameter. On intravenous urography, four patients had a nonfunctioning kidney, three patients had unexplained ureterohydronephrosis, and three patients showed ureteral filling defects, of which only two had irregular contours. On retrograde pyelography, two patients had filling defects (one of which with smooth margins), and one had a truncated ureter. On CT the tumor was clearly demonstrated in only seven patients. We found that ultrasonography can be a useful diagnostic tool in the workup of ureteral tumors.