Sentence:  The pulmonary vein , however , without the limiting supportive tissue septa as in type 1 , , follows a more direct path to the hilum and does not <WSD>maintain</WSD> this close relationship ( figs. 8 , 22 ) . 
Meaning of the word marked with <WSD> tags:  keep in a certain state, position, or activity; e.g., "keep clean"