WO2008112738A1 - Vesicoamniotic shunt - Google Patents

Abstract

An ASD-vesicoamniotic shunt improves the treatment of fetal bladder outlet obstruction by enabling facile making of a hole in the atria. It includes a delivery plunger, a trocar sheath, a delivery sheath housed within the trocar sheath, and an ASD-fistula device housed in the delivery sheath. The ASD-fistula device is deployed by retracting the delivery sheath while holding the delivery plunger against movement.

Description

VESICOAMNIOTIC SHUNT

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to currently pending U.S. Provisional Patent Application 60/894,237, entitled, "Vesicoamniotic Shunt", filed March 12, 2007, the contents of which are herein incorporated by reference

BACKGROUND OF THE INVENTION

1. Field of the invention.

This invention relates to surgical tools. More particularly, it relates to a modified Amplatz delivery system having applications in fetal therapy.

2. Description of the prior art

An atrial septal device (ASD) is conventionally used to seal a hole in the atria. It would be advantageous, however, if such a device could make a hole. A communication could then be made between the bladder of the fetus and the skin (fistula) for fetuses having obstructed urethras.

There is a need for an improved fetal vesicoamniotic shunt because conventional tools for treatment of fetal bladder outlet obstruction are suboptimal.

However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how the identified need could be met.

SUMMARY OF INVENTION

The long-standing but heretofore unfulfilled need for an improved fetal vesicoamniotic shunt is met by a new, useful, and nonobvious invention.

The novel ASD-vesicoamniotic shunt improves the treatment of fetal bladder outlet obstruction. The structure includes a delivery plunger, a trocar sheath, a delivery sheath housed within the trocar sheath, and an ASD-fistula device housed in the delivery sheath and deployable by retracting the delivery sheath while maintaining the delivery plunger against movement. BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:

Fig. 1 A is a diagrammatic depiction of a prior art vesicoamniotic shunt when inserted into a full bladder;

Fig. 1 B is a diagrammatic depiction of a prior art vesicoamniotic shunt when the full bladder of Fig. 1 A has been at least partially emptied;

Fig. 2 is a perspective view of an ASD-vesicoamniotic shunt prior to deployment of its ASD-fistula device;

Fig. 3 is a perspective view of the device depicted in Fig. 2 after deployment of the

ASD-fistula device has begun;

Fig. 4 is a perspective view of the device depicted in Fig. 3 after full deployment of the ASD-fistula device;

Fig. 5A is a top plan view of a novel atrial shunt device (ASD) when fully deployed;

Fig. 5B is a side elevational view of said device in its fully deployed configuration; and

Fig. 5C is a side elevational view of said device in its undeployed configuration inside the lumen of a delivery sheath.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Fig. 1A depicts a conventional vesicoamniotic shunt 10 (a double pigtail catheter) at time "0" when deployed in fetal bladder 12. Up to forty percent (40%) of conventional fetal vesicoamniotic shunts malfunction or become dislodged. Such malfunction is related to changes in the anatomical relationship of the bladder to the fetal skin once drainage begins. To illustrate this fact, Fig. 1 B depicts said conventional shunt 10 at time "1 ," when fetal bladder 12 has moved away from skin surface 14 due to drainage of said bladder. Such drainage applies tension to shunt 10 as is clear from a comparison of Figs. 1 A and 1 B, thereby increasing the chances that dislodgement will occur.

Novel ASD-vesicoamniotic shunt 20 is depicted in Figs. 2-4 and 5A-C. It improves the treatment of fetal bladder outlet obstruction. It includes delivery plunger 22, trocar sheath 24, delivery sheath 26 which is housed within said trocar sheath, and ASD-fistula device 28 which is housed in said delivery sheath. The skin of the fetus is denoted 30 and the bladder wall is denoted 32.

Deployment of ASD-fistula device 28 has begun in Fig. 3. Deployment is accomplished by holding delivery plunger 22 against movement and displacing trocar sheath 24 and hence delivery sheath 26 in the direction indicated by directional arrow 23 in Fig. 2. This removes leading disc 28b and waist 28c from the lumen of delivery sheath 26. Leading disc 28b therefore expands radially outwardly under its inherent bias.

Fig. 4 depicts said device in its fully deployed configuration. Trailing disc 28a has been removed from the lumen of delivery sheath 26 and has expanded under its inherent bias. The diameter of ASD-fistula device 28 when fully deployed is one and a half centimeters (1.5 cm). Waist 28c length is eight millimeters (8 mm), and the diameter of ASD-fistula device 28 is also eight millimeters (8 mm). Delivery plunger 22 should be centered with respect to fistula device 28, i.e., in longitudinal alignment with the longitudinal axis of symmetry of said device 28.

Fig. 5A depicts the novel ASD device 40 in plan view. Fig. 5B depicts said ASD device 40 in side elevation and Fig. 5C depicts said device 40 when in its unexpanded configuration, i.e., as it would appear while in the lumen of a delivery sheath. The discs are denoted 40a, 40b and the waist is denoted 40c.

An upstanding threaded cylinder 42 projects upwardly with respect to disc 40a. Delivery plunger 22 screw theadedly engages upstanding threaded cylinder 42, thereby securing ASD-fistula device 28 to delivery plunger 22. Eccentric opening or defect 44 is the fistula-creating hole. 5 It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying 10 drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. Now that the invention has 15 been described,

Claims

What is claimed is:

1. A method for making a hole in an atria, comprising the steps of:

providing a delivery plunger;

providing a trocar sheath;

housing a delivery sheath within a lumen of said trocar sheath;

housing an ASD-fistula device within a lumen of said delivery sheath;

deploying said ASD-fistula device from said housing of said delivery sheath by holding said delivery plunger against movement and displacing said trocar sheath and said delivery sheath in a distal-to-proximal direction;

whereby a leading disc, waist, and trailing disc of said ASD-fistula device is deployed from said lumen of said delivery sheath; and

whereby said leading disc and trailing disc expand radially outwardly under their respective inherent biases;

whereby a hole is created in said atria to improve the treatment of fetal bladder outlet obstruction.

2. The method of claim 1 , further comprising the steps of:

forming external screw threads on a leading end of said delivery plunger;

providing an upstanding threaded cylinder that projects upwardly with respect to said leading disc;

screw theadedly engaging said leading end of said delivery plunger to said upstanding threaded cylinder, thereby securing said ASD-fistula device to said delivery plunger;

whereby said opening is the fistula-creating hole.