Apparatus is provided for use with a tubular structure (2) in a body of a patient. The apparatus includes an adhesive including first and second components, a container (27), one or more patches (3), and an applicator (1). The container (27) contains the first component of the adhesive and not the second component of the adhesive. The one or more patches (3) include the second component of the adhesive and not the first component of the adhesive. The applicator (1) is configured to removably hold the one or more patches (3), and to place the one or more patches (3) at least partially around the tubular structure (2). Other embodiments are also described.