The value of intravascular ultrasound in the treatment of central venous obstructions in hemodialysis patients

Introduction: Digital subtraction angiography (DSA) is the gold standard in diagnosis and treatment of central venous obstructions (CVOs) in hemodialysis access. However, growing data suggest that DSA might underestimate the degree and morphology of venous outflow stenosis. This could lead to inappropriate CVO management. Intravascular ultrasound (IVUS) has been shown to identify lesion characteristics remaining obscure with angiography. With the current study we suggest IVUS as an eminent imaging modality in CVO management. Methods: Twelve patients (8 male, mean age 62.4 +/- 9 years) were analyzed for suspicion of symptomatic CVO. Both angiography and IVUS evaluation were performed to determine the degree of obstruction before and after PTA. Stent placement was indicated when significant residual stenosis (>50% lumen reduction) was suspected. Results: Conventional plain angiography determined 8 out of 12 central venous lesions significant. Secondary signs of obstruction, i.e., collateral filling, was present in all 12 cases. After PTA, persistent significant stenosis was observed in 3 out of 12 patients. IVUS showed significant lumen reduction in all 12 cases. Additionally, IVUS showed a median cross-sectional area of 24 +/- 12 mm(2) before PTA and 37 +/- 23 mm(2) after PTA (NS). Furthermore, IVUS showed signs of intraluminal fibrotic trabeculations in 9 patients. Stenting was performed in 10 patients with >50% lumen reduction on IVUS after PTA. Conclusions: Conventional angiography seems unreliable to identify all significant aspects of a central venous outflow obstruction. Additional use of IVUS might aid in the decision-making process and select the optimal treatment strategy.