Surgery – Miscellaneous – Methods
Reexamination Certificate
1996-11-19
2001-02-20
Dawson, Glenn K. (Department: 3761)
Surgery
Miscellaneous
Methods
C606S203000, C606S201000
Reexamination Certificate
active
06189538
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the fields of interventional radiology, vascular surgery, cardiology, oncology and medical devices. More specifically, the present invention relates to a novel tourniquet and novel methods for its use.
2. Description of the Related Art
The use of systemic thrombolytic agents to treat deep vein thrombosis (DVT) has been reported previously.
1-5
While these investigations have demonstrated a certain degree of efficacy, the combination of high doses of a thrombolytic agent and the prolonged infusion times necessary to lyse venous clots have raised different safety concerns and limited acknowledgment of thrombolytic therapy as a viable treatment for deep vein thrombosis.
6
This method has had limited success in treating extremity deep vein thrombosis because collateral pathways become the preferred routes of venous outflow, and relatively little thrombolytic agent reaches the thrombus. However, because early clot lysis and re-opening of occluded veins can preserve venous valves and thus prevent or mitigate the development of chronic venous insufficiency,
7,8
investigators have persevered in their attempts to discover safer ways to lyse deep venous thrombi. Early lysis of arterial occulsions has been achieved by using local delivery, instead of systemic infusion of the thrombolytic agent.
9-12
Bleeding complications have remained low compared to systemic infusions.
Using this same treatment philosophy, a few preliminary investigations have successfully used local catheter-directed delivery of a thrombolytic agent to lyse venous clots in the subclavian/axillary veins,
13-17
and more recently in the iliofemoral segment of the lower extremity.
18-24
The results from these preliminary trials have shown improved efficacy and safety of locally-delivered thrombolytic therapy for the treatment of deep vein thrombosis. Thrombus not in easy reach of catheters, however, has not been easily and successfully treated.
The prior art is deficient in the lack of effective means of treating deep vein thrombosis in which the thrombus can not be easily treated using a catheter. The present invention fulfills this longstanding need and desire in the art.
SUMMARY OF THE INVENTION
The present invention provides an effective means of treating deep vein thrombosis in which the thrombus cannot be easily treated using a catheter; i.e., actively lysed by flow-directed therapy. In some cases the flow-directed technique is sufficient to remove thrombus and in other situations, flow-directed infusion is an important adjunct to catheter-directed delivery. Described here is the flow-directed infusion technique for treatment of deep vein thrombosis using pedal assess.
The value of flow-directed thrombolysis derives from the principle that systemic blood flow follows the path of least resistance. The technique of redirecting venous flow with a strategically placed tourniquet provides an effective means of delivering a lytic agent to thrombotic deep veins in the lower extremity. In this manner, venous flow remains imperceptable with duplex and standard venography but becomes a vehicle for delivery of the lytic agent to obstructed vessels. This is a particular advantage when occluded veins are not accessible to catheters, or where catheter placement is difficult or undesired. The involvement of multiple infrapopliteal veins, causing significant impedance to venous outflow, cannot be effectively treated with a single catheter. More often, with multi-segmental venous thrombosis, it is important to mobilize the flow in both the iliofemoral and popliteal tibial areas simultaneously in order to reach a satisfactory outcome. The flow-directed method delivers a high concentration of urokinase to thrombosed deep veins via small pedal cannula. The catheter-directed infusion in the iliac and femoral veins may be combined with a pedal infusion when there is significant occlusive thrombus throughout the extremity. Simultaneous infusions are complimentary and result in more rapid treatment of extensive multi-segmental thrombus. The pedal infusion is effective when used alone for short-segment femoral popliteal and infrapopliteal thrombosis. Research continues to indicate the importance of the posterior tibial valves. Lysis of thrombus in these veins may be significant for preventing post-thrombotic syndrome.
In one aspect of the present invention, there is provided a non-pneumatic tourniquet for use in treating deep vein thrombosis comprising: a band, said band having a first end and a second end, wherein said first end and said second end have means for adjustably connecting to one another; and an adjustable disc, said disc comprised of substantially hard, non-compressable material and wherein said disc is adjustably connected to said band.
In another aspect of the present invention, there is provided a method of treating deep vein thrombosis in which the thrombus cannot be easily treated using a catheter, i.e., actively lysed by flow-directed therapy. To this end, one embodiment of the present invention is drawn to a method for treating deep vein thrombosis, comprising the steps of: placing an intravenous needle in a vein in an area to be treated; determining a pattern of venous blood flow in said area to be treated; securing a tourniquet around said area to be treated, wherein a disc of said tourniquet is positioned over said vein so as to apply pressure to said vein; checking re-direction of blood flow through said area to be treated; infusing said vein through said needle; releasing said tourniquet after an appropriate period of time; and re-securing said tourniquet after an appropriate period of time. To illustrate a detailed example of one embodiment of a method of using the novel tourniquet of the present invention, 1) a small gauge intravenous needle is placed in the dorsal vein of the foot; 2) radioopaque contrast media (“dye”) is injected usually under fluoroscopy to determine the venous anatomy and pattern of venous blood flow; 3) the tourniquet is secured just about the inner ankle bone with the capped disc positioned at the location of the saphenous vein; 4) using fluoroscopy, one then confirms the effective redirecting of contrast into the deep middle veins of the leg; 5) skin is marked to designate the proper location if disc placement as well as tourniquet level; 6) a urokinase infusion is connected to pedal IV the site for continuous “flow-directed” infusion; and 7) release the tourniquet is released 10 minutes/hour and replaced.
Other and further aspects, features, and advantages of the present invention will be apparent from the following description of the presently preferred embodiments of the invention given for the purpose of disclosure.
REFERENCES:
patent: 3586001 (1971-06-01), Sanderson
patent: 4182338 (1980-01-01), Stanulis
patent: 4944289 (1990-07-01), Matthews
patent: 4997438 (1991-03-01), Nipper
patent: 5295996 (1994-03-01), Blair
patent: 5512056 (1996-04-01), Stevens et al.
patent: 5695520 (1997-12-01), Bruckner et al.
patent: 5848981 (1998-12-01), Herbranson
patent: 5873890 (1999-02-01), Porat
Adler Benjamin Aaron
Dawson Glenn K.
LandOfFree
Tourniquet and method of using does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tourniquet and method of using, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tourniquet and method of using will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2595981