Faculty Bibliography

The advantages of autogenous fistulas over grafts and catheters for vascular access in hemodialysis are well recognized and include lower rates of all-cause mortality and infection and significantly decreased total access costs. However, a substantial number of fistulas will never mature and are eventually abandoned. Percutaneous techniques are increasingly used to salvage fistulas to enable maturation and use. The authors report on a patient with a thrombosed immature brachiocephalic dialysis fistula with an occluded outflow vein, in whom fistula function was salvaged through creation of a percutaneous vein-to-vein anastomosis. This technique adds to the growing armamentarium of interventional therapies for occluded venous outflow in hemodialysis access sites

OBJECTIVE: The purpose of this study was to compare, with histopathologic examination of the liver explant as the reference standard, diffusion-weighted MRI with contrast-enhanced subtraction MRI in the assessment of necrosis of hepatocellular carcinoma (HCC) after trans arterial chemoembolization (TACE). MATERIALS AND METHODS: The cases of 21 patients with HCC who underwent MRI after TACE were evaluated. Two independent observers calculated the apparent diffusion coefficient (ADC) of HCC and measured percentage tumor necrosis on subtraction images. The ADCs of necrotic and viable tumor tissues were compared. ADC and percentage necrosis on subtraction images were correlated with percentage necrosis found at pathologic examination. Receiver operating characteristics analysis was performed on the diagnosis of complete tumor necrosis. RESULTS: Twenty-eight HCCs (mean diameter, 2.3 cm) were evaluated. There were significant differences between the ADC of viable tissue and that of necrotic tumor tissue (1.33 +/- 0.41 vs 2.04 +/- 0.38 x 10(-3) mm(2)/s, p < 0.0001). There was significant moderate correlation between ADC and the pathologic finding of percentage necrosis (r = 0.64, p < 0.001) and significant strong correlation between subtraction image and pathologic percentage necrosis (r = 0.89-0.91, depending on the phase; p < 0.001). In the diagnosis of complete tumor necrosis, ADC had an area under the curve, sensitivity, and specificity of 0.85, 75%, and 87.5% compared with 0.82-0.89, 100%, and 58.3-79.1% for subtraction imaging (p > 0.5 between ADC and subtraction imaging). CONCLUSION: Compared with diffusion-weighted imaging, contrast-enhanced MRI with subtraction technique had more significant correlation with the histopathologic findings in the evaluation of necrosis of HCC after TACE. There was no difference, however, between the two methods in diagnosis of complete tumor necrosis

PURPOSE: To assess the retrievability of the G2 inferior vena cava (IVC) filter and factors influencing the safety and technical success of retrieval. MATERIALS AND METHODS: From October 2006 through June 2008, G2 IVC filters were placed in 140 consecutive patients who needed prophylaxis against pulmonary embolism (PE). General indications for filter placement included history of thromboembolic disease (n = 98) and high risk for PE (n = 42); specific indications included contraindication to anticoagulation (n = 120), prophylaxis in addition to anticoagulation (n = 16), and failure of anticoagulation (n = 4). Filter dwell time, technical success of filter retrieval, and complications related to placement or retrieval were retrospectively evaluated in patients who underwent filter removal. RESULTS: Twenty-seven attempts at G2 filter removal were made in 26 patients (12 men; age range, 24-88 years; mean age, 55.4 y) after a mean period of 122 days (range, 11-260 d). Data were collected retrospectively with institutional review board approval. Filter removal was successful in all 27 attempts (100%). Tilting of the filter (> or =15 degrees ) occurred in five cases (18.5%), with probable filter incorporation into the right lateral wall of the IVC in one. Other complications of retrieval such as filter thrombosis, significant filter migration, filter fracture, and caval occlusion were not observed. CONCLUSIONS: G2 IVC filter retrieval has a high technical success rate and a low complication rate. Technical success appears to be unaffected by the dwell time within the reported range

Catheter coatings have the potential to decrease infection and thrombosis in patients with chronic dialysis catheters. We report our midterm experience with a heparin-coated dialysis catheter. This retrospective, case-control study was approved by our Institutional Review Board. A total of 88 tunneled dialysis catheters were inserted over a 13-month period via the internal jugular vein. Thirty-eight uncoated split-tip catheters and 50 heparin-coated catheters were inserted. Primary catheter patency was compared between the two groups using the log rank test, with infection and/or thrombosis considered as catheter failures. Dialysis parameters during the first and last dialysis sessions, including pump speed, actual blood flow, and arterial port pressures, were compared using unpaired t-tests. Primary patency of the uncoated catheters was 86.0 +/- 6.5% at 30 days and 76.1 +/- 8.9% at 90 days. Primary patency of heparin-coated catheters was 92.0 +/- 6.2% at 30 days and 81.6 +/- 8.0% at 90 days (p = 0.87, log rank test). Infection requiring catheter removal occurred in four patients with uncoated catheters and two patients with heparin-coated catheters (p = 0.23). Catheter thrombosis requiring catheter replacement or thrombolysis occurred in one patient with an uncoated catheter and two patients with heparin-coated catheters (p = 0.9). No differences in catheter function during hemodialysis were seen between the two groups. In conclusion, the heparin-coated catheter did not show a significantly longer patency compared to the uncoated catheter. The flow characteristics of this device were comparable to those of the conventional uncoated catheter. A demonstrable benefit of the heparin-coated catheter in randomized trials is needed before a recommendation for routine implementation can be made