fig7

Figure 7. Kaplan-Meier curve showing primary- and primary-assisted patency rates. Solid and dotted lines indicate primary patency and primary-assisted patency, respectively. Vertical lines on both lines indicate censored observations. The primary patency rates at 1, 3, 5, and 10 years after the initial drainage tube placement were 75%, 70%, 70%, and 68%, respectively. The primary-assisted patency rates at 1, 3, 5, and 10 years after the initial drainage tube placement were 94%, 92%, 88%, 88%, respectively