Soft lock wire guide and neuro-surgery assembly using same

A wire guide comprising:

• an elongate hollow tube with a distal segment that defines a plurality of openings arranged in a pattern so that the distal segment is more flexible than a proximal segment of the elongate hollow tube;
• an inner tube positioned inside the elongate hollow tube and having a closed distal end;
• an inflation device with a reservoir of liquid fluidly connected to a proximal end of the inner tube;
• the wire guide having a stiff condition in which the inner tube is pressurized by the liquid causing an external surface of the inner tube to bear against an internal surface of the elongate hollow tube;
• the wire guide having a soft condition in which the inner tube is depressurized causing the external surface of the inner tube to be at least partially out of contact with the internal surface of the elongate hollow tube;
• wherein the inner tube protrudes into a portion, which is less than all, of the plurality of openings when the distal segment is in a curved configuration and the wire guide is in the stiff condition;
• wherein a shape of each of the plurality of openings changes responsive to flexure of the distal segment away from a straight configuration.

A method of operating a neuro-surgery assembly that includes a wire guide with an elongate hollow tube with a distal segment that defines a plurality of openings arranged in a pattern so that the distal segment is more flexible than a proximal segment of the elongate hollow tube;

• an inner tube positioned inside the elongate hollow tube and having a closed distal end;
• the wire guide having a stiff condition in which the inner tube is pressurized by a liquid causing an external surface of the inner tube to bear against an internal surface of the elongate hollow tube;
• the wire guide having a soft condition in which the inner tube is depressurized causing the external surface of the inner tube to be at least partially out of contact with the internal surface of the elongate hollow tube;
• the method comprising the steps of:
• advancing a wire guide around a turn of a tortuous pathway toward a treatment site in a brain while the wire guide is in the soft condition;
• stopping the wire guide in the turn with the distal segment in a curved configuration;
• sliding a neuro-catheter over the wire guide toward the turn;
• changing the wire guide from the soft condition to the stiff condition when a distal end of the neuro-catheter is proximal to the distal segment, and the stiff condition includes the inner tube protruding into a portion, which is less than all, of the plurality of openings;
• sliding the neuro-catheter around the turn and over the distal segment toward the treatment site;
• changing the wire guide from the stiff condition back to the soft condition;
• stopping the neuro-catheter at the treatment site;
• maintaining the neuro-catheter at the treatment site while withdrawing the wire guide in the soft condition from the neuro-catheter.