Method and Apparatus for Placing a Cannula in a Bladder

Apparatus for enlarging a small surgical pathway through a bladder wall and an abdominal wall and placing a cannula in the enlarged opening, comprising a placement guide, an obturator and the cannula, wherein:

• the cannula comprises a conduit extending between a forward end and a rear end, the conduit defining a central channel extending between the forward and rear ends of the conduit, the central channel providing access through the cannula;
• the placement guide comprises an elongated flexible guide tube extending between a forward end and a rear end, the guide tube defining a lumen extending from the forward end to the rear end, the placement guide also having a flexible membrane at a forward end of the guide tube which expands out from the guide tube as a placement balloon in response to fluid supplied through the lumen;
• the obturator comprises a housing and a hollow obturator shaft and at least one blade, the obturator shaft extending between a forward end and a rear end, at least one blade positioned at the forward end of the obturator shaft and movable between an extended position where the blade projects outward from the forward end of the obturator shaft and a retracted position where the blade withdraws interiorly into the forward end of the obturator shaft, the obturator also comprising an actuation member and a selective actuation mechanism, the actuation member movably positioned within the obturator shaft and operatively connected at the forward end to the blade to move the blade between the extended position and the retracted position with movement within the actuation member, the rear end of the actuation member extending into the housing, the actuation mechanism positioned within the housing and operatively connected to the rear end of the actuation member to move the actuation member in response to selective actuation of the activation mechanism to thereby move the blade between the extended and retracted positions;
• the obturator further comprising a selectively releasable connecting mechanism for connecting the obturator and the cannula as a unit with the obturator shaft extending through the central channel and the conduit of the cannula surrounding the obturator shaft, the forward end of the obturator shaft extending forward beyond the forward end of the cannula and the blade located forward beyond the forward end of the cannula when the obturator and the cannula are connected as a unit;
• the obturator further defining a center passage which extends from the housing through the obturator shaft and through the forward end of the obturator shaft, the center passage receiving the guide tube of the placement guide with the forward end of the placement guide extending forward from the forward end of the obturator shaft and with the rear end of the placement guide extending rearward from the center passage, the center passage permitting movement of the connected obturator and cannula along the guide tube;
• and
• the actuation mechanism and the actuation member operatively moving the blade between the extended and retracted positions with the guide tube of the placement guide positioned in the center passage.