Abstract: Objective To explore the indication of balloon dilatation and the selection of balloon diameter during tunneled cuffed catheter replacement in the presence of fibroblastic sleeve and/or superior vena cava stenosis or occlusion and examine the causes of long fibroblastic sleeve formation and superior vena cava stenosis. Methods Over the past 6 years, 130 patients with balloon dilatation and 12 patients with difficult catheterization due to no balloon dilatation were analyzed retrospectively. The causes and treatments of difficult catheterization were recorded. Results A total of 68 patients encountered difficulties of inserting peel-away sheath without balloon dilatation. Total median time of catheter indwelling (catheter in the same fibroblastic sleeve) was 5.0 (2.5-16.0) years. In 12 patients with difficult extubation, peel-away sheath could be placed only after fibroblastic sleeve was expanded by balloon. Azygos vein imaging was performed in 28 patients with severe stenosis or occlusion of superior vena cava or cava atrial junction. Catheters were inserted 23 times after balloon dilation and 5 times under guide wire guidance.The diameter range of expanded fibroblastic sleeve balloon was (6-12) mm;The diameter of balloon for dilated superior vena cava and atria cava junction lesions ranged from 7-12 mm. Among 21 patients without a previous history of catheterization and not replacing, 6/9 patients with original catheter tip in right atrium had no obvious stenosis of superior vena cava while 12 cases with original catheter tip placed at the junction of atria cava and superior vena cava had stenosis of junction of atria cava or superior vena cava. After operation, there were no vascular rupture, symptomatic pulmonary embolism or infection complications. Conclusion Difficulty of inserting peel-away sheath is an absolute indication of balloon dilatation of fibroblastic sleeve. Patients with difficulty in extubation and catheter retention for>2.5 years may need balloon dilatation of fibroblastic sleeve before inserting peel-away sheath. For patients with moderate/severe stenosis or occlusion at proximal end of superior vena cava or at the junction of cava and atrium, especially those with azygos vein development, expanding lesion site with balloon is preferred before catheterization. And 8 mm diameter balloon is recommended for expanding fibroblastic sleeve while 10 mm diameter balloon for expanding the stenosis at the junction of superior vena cava and atria cava. Severe stenosis or occlusive lesions should be expanded stepwise. Central vein stenosis rate with catheter tip in right atrium is lower.