Apparatus is provided for implanting a prosthetic device (108) in a patient, the apparatus includes a trocar tube (101), a first portion of which is configured to be placed in a left ventricle (12) of the patient during a procedure for implantation of the prosthetic device (108), and a second portion of which is configured to be placed in an extracardiac location during the procedure. The first portion is shaped so as to define at least one opening to an interior thereof. One or more flexible bypass tubes (103, 104, 106), each of which is coupled to the second portion, and each of which is configured to be coupled to at least one artery (20, 21, 30) of the patient, so as to create a blood flow bypass path during the procedure, from the left ventricle (12), via the opening and the bypass tubes (103, 105, 106), to the at least one artery (20, 21, 30). Other embodiments are also described.
