Adjustable vascular ring, means for treating sfs syndrome and implantable kit comprising such a ring, mould and method for obtaining such a ring
AssigneeMedical Innovation Developpement
InventorLudovic CAZENAVE
Life of this patent
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Abstract
The invention relates to a perivascular ring having an inner diameter adjustable by inflation/deflation and adapted to be implanted and closed about a vessel for controlling the inner diameter of said vessel and thus the flow and/or pressure of a fluid flowing in said vessel. The ring of the invention is capable of regulating blood flow to the liver, in particular after an hepatectomy or hepatic transplant, and to substantially improve the survival chances of the patient. The ring according the invention has an adjustable inner diameter (Øi) for implantation and locking about a vessel.
Claims20
1- Ring with an adjustable inner diameter, intended to be implanted and closed around a biological duct, preferably a vessel, in order to control the diameter of this duct and thus the flow rate and/or pressure of a fluid circulating in the duct, this ring comprising:
- an outer belt with a constant diameter in the closed position;
- an inner chamber that can be inflated and deflated in the closed position, so as to vary its inner diameter;
- a flexible inflation/deflation tube one end of which is connected to the inner chamber and the other end of which is intended to be connected to inflation means;
- the outer belt and the inner chamber forming open collars, the outer belt being equipped with closing means for closing the ring around the duct;
- wherein the inner chamber, at rest and in the closed position, has an inner diameter corresponding to the smallest reduced diameter required when in use for controlling the diameter of the duct and
- wherein the closing means comprise two lips capable of being joined to one another and to be separated from one another, after the ring is implanted and closed around a biological duct, by over-inflation of the inner chamber.
2- Ring according to claim 1, wherein the inner chamber has no invagination at rest and in the closed position of the ring and in that the inner edge of the inner chamber intended to be in contact with the duct has a substantially circular shape.
3- Ring according to claim 1, wherein the inner diameter decreases by inflation and increases by deflation.
4- Ring according to claim 1, wherein the outer lips extend in the centrifugal direction and are capable of being joined to one another in a diametral plane, in a reversible manner, in order to close the ring around the duct.
5- Ring according to claim 1, comprising at least one radio-opaque part.
6- Means for treating Small For Size syndrome suitable for hepatectomies and liver transplants, comprising the ring as defined in claim 1.
7- Means according to claim 6, also comprising inflation means connected to the end of the flexible tube, the ring being intended to be put in place and locked around the portal vein of a patient, upstream of the liver, the inflation means and the ring being adapted in order to reduce by at the most 55%, preferably by at the most 50%, the diameter of the portal vein Dvp to a minimal value Dvpr and in order to then allow the modulation of Dvp between Dvpr and its normal diameter Dvpn in which the ring does not reduce Dvp, said modulation consisting of deflating the ring in order to increase Øi and therefore Dvp from Dvpr to Dvpn, so as to reduce the portal pressure downstream of the ring and maintain the intrahepatic pressure at a value less than or equal to 20 mm Hg, preferably at 15 mmHg and thus to treat/limit Small For Size syndrome, suitable for hepatectomies and liver transplants.
8- Kit that can be implanted by surgical route, allowing the adjustment of the inner diameter of a duct and thus the flow rate of a fluid circulating in this duct, this kit comprising:
- a ring according to claim 1;
- an inflation/deflation module intended to be connected to the distal end of the flexible inflation/deflation tube, in order to allow the in situ injection of an inflation/deflation fluid into the inner chamber or the in situ extraction of an inflation/deflation fluid out of the inner chamber.
9- Kit according to claim 8, further comprising a suture for closing the ring, this suture being selected to break in the event of overpressure in the ring.
10- Ring according to claim 1, wherein the closing means comprise a suture threaded through at least one perforation made in the lips, the suture being selected to break in the event of overpressure in the ring.
11- Ring according to claim 10, wherein the suture is resorbable.
12- Ring according to claim 1, wherein the inner chamber forms, at rest and in the non-closed position of the ring, an open collar on an angular sector less than or equal to 5° and the outer belt forms, at rest and in the non-closed position of the ring, an open collar over an angular sector less than or equal to 10°,
13- Ring according to claim 1, wherein the lips have contact surfaces facing each other, the closing means comprising at least one perforation arranged on the contact surface of a first of the two lips and at least one protrusion protruding from the contact surface of a second of the two lips, the protrusion and the perforation being configured so that the protrusion is retained in the perforation by fitting, the fitting being selected to be released in the event of overpressure in the ring.
14- Ring according to claim 13, wherein the perforation is a through hole formed in the first lip and the protrusion is a tongue comprising a fitting portion attached to the contact surface of the second lip and sized to be retained in the through hole by friction fitting.
15- Ring according to claim 14, wherein the tongue comprises a grasping portion adjacent the fitting portion opposite the second lip, the grasping portion being sized to pass through the through hole and to be grasped by a user.
16- Ring according to claim 13, wherein the perforation is a through hole formed in the first lip and the protrusion is a tongue, the tongue comprising a fitting portion attached to the contact surface of the second lip and sized to be arranged within in the through hole, and an enlarged portion sized to rest on a surface of the first lip opposite the contact face of the first lip.
17- Ring according to claim 16, wherein the tongue comprises a grasping portion adjacent the fitting portion opposite the second lip, the grasping portion being sized to pass through the through hole and to be grasped by a user.
18- Means according to claim 7, wherein the inflation means and the ring are adapted to reduce by at the most 50% the diameter of the portal vein Dvp to a minimal value Dvpr.
19- Means according to claim 7, wherein the modulation of Dvp consists in deflating the ring in order to increase Øi and therefore Dvp from Dvpr to Dvpn, so as to reduce the portal pressure downstream of the ring and maintain the intrahepatic pressure at a value less than or equal to 15 mmHg.
20- Kit according to claim 9, wherein the suture is resorbable.