Antenatal shunt

• US 4,474,569 A
• Filed: 06/28/1982
• Issued: 10/02/1984
• Est. Priority Date: 06/28/1982
• Status: Expired due to Term

• Current Assignee: DePuy Orthopaedics Incorporated (Johnson & Johnson)
• Original Assignee: Denver Surgical Developments Incorporated
• Inventors: Newkirk, John B.
• Primary Examiner(s): Coven, Edward M.
• Application Number:
  US06/392,872
• Time in Patent Office: 827 Days
• Field of Search: 604/8, 604/9, 604/10, 604/891, 604/171, 604/247, 604/51, 604/164, 604/175
• US Class Current: 604/8
• CPC Class Codes: A61M 2210/145 Embryo, fetus
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves

Abstract

An antenatal shunt is provided for implantation in utero to drain blocked fluid cavities within a fetus. The shunt includes a proximal catheter having one or more expandable wing anchors strategically positioned on the catheter, a distal tube having an additional anchor and a retracting tab provided at the free end of the distal tube. A check-valve may be provided in the catheter to allow fluid to flow in only one direction through the shunt. The shunt is sized and arranged to be implanted by means of a hollow surgical needle into the fetus by the use of ultrasonography as a guidance aid. Suitable apertures are provided in the proximal and distal free ends of the shunt to allow the flow of fluid from the fluid cavity in the fetus to the amniotic sac. Expandable anchors are included which are capable of being folded for insertion and movement through the needle during implantation. The arms expand upon release from the needle to provide a secure anchoring arrangement. The antenatal shunts provided in the present invention can be utilized for various fetal abnormalities such as antenatal hydrocephalus or a blocked urinary condition.

Claims

1. An antenatal micro-shunt for complete implantation inutero in a fetus by use of a thin-hollow surgical needle, so that a blocked fluid cavity within the fetus can be continuously drained, said shunt comprising:

a thin body tube fabricated from a flexible material and having an internal fluid passageway, said tube having an outside diameter small enough to pass freely through the interior of said surgical implanting needle;

the proximal and distal ends of said tube each having at least one aperture formed diametrically through the tube to allow the entrance of the fluid to the internal passageway;

two or more anchors are attached to the body of said tube, at least one of said anchors is attached near the distal end of the tube while at least one other anchor is attached to a portion generally near the midpoint of said tube;

at least one of the anchors near the midpoint of said tube has angularly positioned expandable arms wherein when said shunt is being implanted through said needle the arms are folded against the body of the tube to allow it to pass freely through the needle and to expand in an outwardly direction forming an acute angle with the body of the tube when the anchor clears the end of the needle whereby the anchor can be placed on one side of the membrane forming the cavity to be drained with the arms angled toward the membrane while the distal end anchor attached thereto prevents the tube from passing through the membrane in the opposite direction;

said angled arm anchor is formed from a single strip of thin, flexible material having an oval aperture formed near the midpoint of said strip, the tube being threaded through the aperture of said strip and the strip being permanently affixed to the outside of said tube, the narrowest dimension of said oval aperture being sized slightly smaller than the outside diameter of the tube so that the ends of the strip are biased in the same direction to form an acute angle with the longitudinal axis of the tube; and

at least one of the anchors formed near the distal end of said tube is an enlarged sleeve mounted on the outer surface of the tube, said sleeve having an outside diameter sufficient to restrict the inward movement of said tube into said cavity while at the same time being smaller than the inside diameter of said needle to allow said implantation.

2. An antenatal shunt as described in claim 1, wherein:

at least one of the anchors near the distal end of the tube is an expandable anchor with the arms arranged to expand angularly outward from said tube to form an acute angle in a direction toward the midpoint expandable anchor whereby the expandable arm anchors can be positioned on either side of the membrane of the cavity to be drained to prevent dislodgement of the body tube in either direction.

3. An antenatal shunt as described in claim 1, which further includes:

a valve for restricting the fluid flow through the tube in only one direction whereby the fluid will exit from the blocked cavity and through the distal end of said tube.