title: Diagnostic value of computerized tomography venography in detecting stenosis and occlusion of subclavian vein and superior vena in chronic renal failure patients.
abstract: BACKGROUND
  Currently, venography is the standard diagnostic method to examine veins before implementing access, which is invasive in nature. Computerized tomography venography (CTV) can simultaneously indicate deep and superficial venous systems in the upper extremity and their relation to the surrounding anatomical structures; however, its diagnostic value in the detection of central venous disease has yet to be defined. The aim of this study was to determine the diagnostic value of CT venography compared to venography in the diagnosis of stenosis and the occlusion of subclavian veins and the superior vena in renal failure patients.
  
  
  METHODS
  This cross-sectional study was conducted from January to September 2015 on patients with chronic renal failure undergoing upper extremity venography at the Radiology Department of Imam Reza Hospital in Mashhad, Iran. We excluded patients with catheters in their jugular and subclavian vein routes, venous hypertension with reverse-function fistula, or sensitivity to contrast agents. Several factors, including age, gender, catheterization record in jugular and subclavian veins, and fistula record in the upper extremity, as well as clinical symptoms consisting of edema, dermatitis, and ulcers in these organs, were recorded in the corresponding form. Then, the patients consecutively underwent indirect venography and CT venography and traces of stenosis (more than 50%) or complete occlusion in the subclavian vein and superior vena were recorded. The data were analyzed using SPSS software by the chi-squared test, and sensitivity, specificity, and positive and negative predictive values were calculated by means of MedCalc Online, version 16.2.
  
  
  RESULTS
  The study was conducted on 40 patients (26 males and 14 females) with a mean age of 46.7 ± 10.4 years. In this study, 58 subclavian veins, as well as 32 superior vena cava, were studied. The results showed that the diagnostic value of CTV in the detection of subclavian stenosis had a sensitivity and a specificity of 88.2 and 97.5%, respectively. Moreover, in the superior vena cava, the greatest CTV diagnostic sensitivity and specificity was related to vein stenosis detection (sensitivity = 88.8%; specificity = 100%).
  
  
  CONCLUSIONS
  It seems that the CTV, based on its high sensitivity, specificity, and predictive value, can be used as an efficient tool in the study of stenosis in subclavian veins and superior vena in patients undergoing venography.
authors.affiliation: M.D., Resident of Radiology, Department of Radiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Banafsheh
authors.initials: B
authors.lastname: Bakhshoude
authors.affiliation: M.D., Associate Professor, Department of Vascular Surgery, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Ravari
authors.affiliation: M.D., Associate Professor, Department of Vascular Surgery, Vascular and Endovascular Surgery Research Center, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Gholam Hosein
authors.initials: GH
authors.lastname: Kazemzadeh
authors.affiliation: M.D., Associate Professor, Department of Radiology, Vascular and Endovascular Surgery Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Masoud Pezeshki
authors.initials: MP
authors.lastname: Rad
keywords: CT venography; Central venous; Hemodialysis; Renal failure; Venography