Surgery – Devices transferring fluids from within one area of body to... – With flow control means
Patent
1986-05-01
1989-05-09
Pellegrino, Stephen C.
Surgery
Devices transferring fluids from within one area of body to...
With flow control means
128 79, 128DIG25, 600 31, 623 1, 251342, A61F 248, F16K 1520
Patent
active
048285447
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
This invention relates to the control of blood flow, and more particularly to the control of blood flow through an artery to vein fistula.
BACKGROUND ART
The problem of blood flow control through an arterio-venous fistula or a veno-venous fistula is described, inter alia, in the following publications: and Gerard Taylor, Angiology 3, 415-430, 1952. patterns and encephalopathy": James Sarfeh et al, Ann. Surg. Vol. 197 No. 4 422-426.
As stated by Holman and Taylor, the effects of a fistula depend in large measure upon its size, but even more significantly, upon the relationship of its size to the calibre of the vessels in which the fistula lies. Bearing directly upon this relationship is the concept that a vessel at any given point in the arterial tree has an arterial end pressure sufficient to overcome the peripheral resistance distal to it, the one being commensurate with the other. The larger the vessel, therefore, the greater will be the peripheral resistance of the capillary bed supplied by it, and consequently the greater must be the arterial end pressure to overcome it.
Also, the larger the vessels between which a fistula lies, the greater will be the difference between the low pressure of the central venous bed and the high peripheral resistance of the capillary bed distal to the fistula, thus increasing the tendency for blood to avoid the capillary bed and to flow into the central venous bed.
Moreover, the larger the artery in which the fistula lies, the higher will be the artery end pressure directing blood through the fistula into the large central reservoir of low venous pressure with a corresponding increase in velocity of blood through the fistula. Given a uniform size of fistula, the nearer to the heart this fistula lies in the main arterial tree, the greater will be the volume of blood pouring through it.
Thus, the work of Holman and Taylor was, in essence, concerned with the location and size of a fistula rather than upon the control of flow of blood through the fistula.
The work of Sarfeh et al was concerned with the use of portacaval H-grafts of different diameters and not with the control of blood flow through the grafts.
Although neither of the abovementioned publications refers to any device for controlling the flow of blood through a fistula, an implantable device for restricting the flow of blood through a major blood vessel such as an artery is disclosed in U.S. Pat. No. 3,730,186 of Edmunds et al.
The Edmunds device consists of an inflatable, flexible annulus, generally circular in shape but not a closed circle, which has a non-distensible outer wall so that upon inflation all distention or expansion is inward.
The Edmunds device is placed around an artery or other blood vessel and the ring is then closed by suturing together pre-formed tabs attached to the annulus, or by suturing together the ends of an overlaping tape to hold the vessel firmly.
Upon inflation, inward distention of the inflatable annulus constricts the vessel and flow of blood therethrough is accordingly restricted. Inflation and deflation are effected through a self-sealing hollow bulb and a non-distensible tube connecting the bulb to the interior of the inflatable annulus.
Although U.S. Pat. No. 3,730,186 does disclose an implantable adjustable extravascular occluding band adapted to restrict the flow of blood, the only application described in the specification is concerned with the control of blood flow through an artery and does not relate to the diversion of blood flow from arteries between veins and venous sinks.
In general terms, blood flows from an artery through an organ (e.g. liver) which may be considered as an venous sink and then back to a vein. When the normal blood flow system ceases to operate correctly, various kinds of vascular problems may arise.
For example, in recent years, it has become increasingly clear that very frequently erectile impotence is associated with penile vascular problems, although they may not be the only contributive factors to the symptom which is oft
REFERENCES:
patent: 3419008 (1968-12-01), Plishner
patent: 3530928 (1970-09-01), Swinney
patent: 3534771 (1970-10-01), Eyerdam
patent: 3675656 (1972-07-01), Hakim
patent: 3699957 (1972-10-01), Robinson
patent: 3730186 (1973-05-01), Edmunds, Jr. et al.
patent: 3744063 (1973-07-01), McWhorter et al.
patent: 3750194 (1973-08-01), Summers
patent: 3758073 (1973-09-01), Schulte
patent: 3939821 (1976-02-01), Roth
patent: 3985140 (1976-10-01), Harris
patent: 3998222 (1976-12-01), Shihata
patent: 4044401 (1977-08-01), Guiset
patent: 4256093 (1981-03-01), Helms et al.
patent: 4428365 (1984-01-01), Hakky
patent: 4475899 (1984-10-01), Muller
patent: 4501263 (1985-02-01), Harbuck
patent: 4586919 (1986-05-01), Taheri
patent: 4587954 (1986-05-01), Haber
patent: 4592754 (1986-06-01), Gupte et al.
patent: 4640493 (1987-02-01), Dudzik
Lane Rodney J.
Pace Gary W.
Taylor George R.
Lewis Ralph
Pellegrino Stephen C.
Quotidian No. 100 PTY Limited
LandOfFree
Control of blood flow does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control of blood flow, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control of blood flow will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-86927