A drainage tube assembly comprises an inner tubular member and an outer tubular member. The inner tubular member has an inner wall, an outer wall, and a plurality of apertures extending from the outer wall thereof to the inner wall thereof. The outer tubular member has an inner wall, an outer wall, and a plurality of apertures extending from the outer wall thereof to the inner wall thereof. The inner tubular member and the outer tubular member are coaxial with the outer wall of the inner tubular member abutting the inner wall of the outer tubular member. Corresponding ones of the apertures of the inner tubular member and the apertures of the outer tubular member are aligned. The inner tubular member is slidably removable from the drainage tube assembly. The apertures of the inner and outer tubular members may be oblique relative a longitudinal axis of the drainage tube assembly.