The Nemours Foundation

Other

Gary Magram

An apparatus for draining cerebrospinal fluid from the ventricle of a brain includes an inner rigid tube and an outer flexible, elastic tube. The proximal end of the flexible tube has perforations to admit fluid into the elastic tube lumen in which the fluid is conducted to the distal end where the fluid exits into the remainder of a drain system, such as a ventriculoperitoneal shunt. The rigid tube contains an elbow bend intermediate the ends. In one form of the apparatus, the rigid tube has a first tubing nipple near one end and a second nipple intermediate the first nipple and the elbow bend. The first nipple extends outside and beyond the distal end of the flexible tube. The second nipple can be used to fasten the flexible tube to the rigid tube. The fastening method can employ a circumferential ligature as with suture thread or with a novel non-elastically deformable sleeve type of compression fitting. When implanted, the intercranial portion of the drain cannula descends directly into the ventricle from a burr hole in the skull and the extracranial portion remains flush adjacent the skull under the scalp. The rigid tube maintains the lumen in a patent condition at the burr hole despite the substantial angle between the distal and proximal portions of the flexible tube. The location of the two nipples permits fastening of the rigid tube to the flexible tube and joinder of the drain cannula to the drain system to be accomplished completely outside the burr hole.

Drain cannula

A guidewire useful for feeding a medical catheter through a body duct network to a distant target site within the body has a flexible distal portion. The distal portion facilitates threading the guidewire in a tortuous path through acute bends at branch junctions in the duct network. The guidewire end is able to feed into very delicate vessels such as ventricles of the brain and the spinal canal without puncturing the walls or damaging organs. The novel guidewire includes beads displaced longitudinally at the distal end of a core wire. The beads are separated by a gap distance. The core wire can flex at points within the gaps between beads which allows the dial end of the guidewire to bend at branch junctions and to conform to the curvature in the vessel duct. The beads can be fixed to the core wire or they can move freely along the distal portion. Also, beads freely sliding along the core wire can be compressed against each other to control the degrees of stiffness and curvature of the distal portion by manipulating the proximal end of the guidewire outside the body during deployment of the guidewire. An insertion tube is provided for initially feeding the flexible guidewire end into the body duct.

Cathether guidewire

A sample container and a fluid collection apparatus are disclosed for withdrawing samples for fluid analysis purposes of unpressurized body fluid from an internal body cavity. The container and apparatus are primarily useful for sampling cerebrospinal fluid obtained through a lumbar puncture or shunt tap. The container and apparatus provide a completely enclosed sample environment which protects the sample from external contamination during the sample-taking process. The enclosed environment also protects sample-taking personnel against direct contact with the fluid. The novel sample container includes an inflatable pouch with a balloon that expands on filling without significantly raising back pressure on the fluid draining from the patient. The pouch is affixed within a transparent, rigid sheath by an inlet port. The apparatus includes a needle assembly with an internal rubber septum. The septum prevents fluid from leaking out when a stylet is removed from the needle bore after the lumbar puncture is performed.

Body fluid collection apparatus

A method for securing the connection of a medical tube to a port of a fluid transfer instrument. The method provides connections with superior resistance to unexpected disconnection, and thus is particularly beneficial for joining elastic tubes which are implanted within the body for conducting body fluid from one internal location to another or between the body and an external location. The novel method includes inserting a rigid nipple on the port into the lumen of an elastically deformable tube to be joined to the port, placing an initially loose fitting, nonelastically deformable sleeve around the tube on the nipple, and deforming the sleeve radially toward the nipple to clamp the tube between the sleeve and nipple. The extent of deformation is controlled to prevent damaging the tube. A tool for clamping the sleeve to a controlled extent of deformation is also provided. The invention further provides novel medical tube couplings which include nonelastically deformable sleeves for clamping a tube to a nipple. The novel couplings are incorporated in medical tube connectors for splicing together tubes. The method and articles of this invention are preferably useful in ventriculoperitoneal shunt procedures. A shunt tube connector has been discovered which obviates the need to tie an intradural ligature around a tube joint of a proximal catheter for draining cerebrospinal fluid from a ventricle of the brain. Medical tube couplings of this invention are preferably made of titanium containing metal to provide radio-opacity without interfering with magnetic resonance imaging.

Cannula connector and method of connecting medical tubes

An apparatus is disclosed for draining cerebrospinal fluid from within a patient's body to a location outside the patient's body. The novel apparatus features a fluid accumulator located serially between the ventricular catheter and the external location. The accumulator holds an amount of fluid which can flow bidirectionally between the patient and the accumulator so as to replenish any excess fluid that surges from the patient due to sudden, unexpected movements, such as sneezing, coughing, suddenly changing from recumbent to upright position and systolic contractions. The accumulator serves to maintain the height of the fluid column in the apparatus at a steady level, despite the sudden movements. Thus the hydrostatic pressure exerted on the cerebrospinal spaces by the fluid, which controls intracranial pressure, remains substantially constant.

External cerebrospinal fluid drain apparatus

A valve for preventing excessive cerebrospinal fluid flow in ventriculoperitoneal shunt, known as 'siphoning', which occurs when a patient rapidly moves from a recumbent to an upright position, is described. The valve includes at least one valve unit containing within a cerebrospinal fluid (CSF)-filled cavity, a freely moveable float which is buoyant in CSF. The valve is subcutaneously implanted in the patient in an upright orientation in which the entrance port of the valve unit is elevated higher than the cavity while the patient is upright. In this orientation, the float rises to the top of the CSF-filled cavity where it seals against a seat of the entrance port. The float thus stops flow until intracranial pressure sufficiently exceeds the buoyant force. The casing generally has a contoured sectional profile. When the patient reclines, the valve orients so that the float rises to a high region of the casing which is away from the entrance seat thereby allowing CSF to flow through. The contour of the casing is selected to increase hydrodynamic force on the float in the direction of flow when flow rate increases. This causes the float to contact a seat of the valve unit exit port when flow exceeds a predetermined amount. The novel valve thus provides the capability to prevent excessive drainage even when the patient is recumbent, for example, caused by coughing or sneezing.

Antisiphoning valve

A prosthesis and method are disclosed for patching openings in body membranes such as the dura mater. The novel prosthesis includes patch comprising a patch flange and a suture flange extending circumferentially around the patch. The patch is implanted inside the membrane such that the patch completely covers the opening to be closed. The lip of the opening laps the suture flange and is secured by sewing sutures through the suture flange and the lip, but not through the patch. Accordingly, the tissue underlying the patch is shielded from the suture threads and perforations by the patch flange. The patch is of lubricious and biologically inert materials that is effectively nonadhesive to scar growth which forms on healing wounds. Thus, the novel prosthesis reduces the potential for adhesion between the underlying tissues and the membrane due to scar formation following surgery, particularly surgery on the central nervous system.

Body membrane prosthesis

A cerebrospinal fluid shunt includes an inner tube for supplying the fluid only from brain ventricles to the peritoneum region of a subject and an outer tube arranged so the fluid remains resident in the outer tube without flowing to the peritoneum region. Fluid in the outer tube exerts pressure through a wall of the inner tube on the fluid in the inner tube to regulate flow of the fluid through the inner tube to the peritoneum region. The shunt includes a catheter including plural openings through which the fluid flows. The openings are arranged so tissue growth through the openings does not occlude flow of the fluid within the catheter. The catheter and shunt having an external pressure responsive collapsible wall and an internal spring for inhibiting catheter collapsing and kinking.

Growing community of inventors

Greenville, DE, United States of America

Gary Magram