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(12) United States Patent ao) Patent No.: us 6,488,643 Bi
Tumey et al. (45) Date of Patent: Dec. 3,2002
(54) WOUND HEALING FOOT WRAP
(75) Inventors: David M. Tumey, San Antonio, TX
(US); L. Tab Randolph, San Antonio,
(73) Assignee: KCI Licensing, Inc., San Antonio, TX (US)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/168,598
(22) Filed: Oct. 8, 1998
(51) Int. C I. A61F 13/00
(52) U.S. CI 602/13; 602/23; 602/30;
(58) Field of Search 602/13, 30, 23;
(56) References Cited
U.S. PATENT DOCUMENTS
3,245,405 A * 4/1966 Gardner
3,920,006 A 11/1975 Lapidus 128/24.1
4,614,179 A 9/1986 Gardner et al 128/64
4,738,257 A 4/1988 Meyer et al 128/156
5,031,604 A 7/1991 Dye 128/64
5,115,801 A 5/1992 Cartmell et al 602/48
5,176,663 A 1/1993 Svedman et al 604/305
5,244,457 A 9/1993 Karami et al 602/55
Caputo, G.M. et al, The Total Contact Cast: A Method for Treating Neuropathic Diabetic Ulcers, American Family Physician, Feb. 1, 1997, 605-11 and editorial 425-26. Cherry, G.W. et al., Bandaging in the Treatment ol Venous Ulcers: A European View, Ostomy/Wound Management, Nov./Dec. 1996, 13S-18S.
Mayrovitz, H.N. et al., Effects ol Compression Bandaging on Lower Extremity Skin Microcirculation, WOUNDS, Nov./Dec. 1996. 200-07.
Phillips, T, Leg Ulcer Management, Dermatology Nursing, Oct. 1996, vol. 5, No. 8, 333^10.
Sieggreen, M.Y. et al., Managing Leg Ulcers, Nursing, Dec. 1996, 41-46.
U.S. Patent Application No. 08/039,574 filed Mar. 25,1993. Kinetic Concepts, Inc., The Plexipulse All in 1 System, Date Unknown.
Rastgeldi, S. Article in Two Parts: "I. Pressure Treatment ol Peripheral Vascular Disease," and "II. Intermittent Pressure Treatment ol Peripheral Vascular Disease, A Survey ol Sixteen years Personal Experience," published in Opuscula Medica, Supplemetum XXXVII 1972, Gundad av Sixten Kallner 1956.
* cited by examiner
Primary Examiner—-John G. Weiss
Assistant Examiner—Kelvin Hart
A medical wrap for the promotion ol diabetic and like wound healing generally comprises a multi-layered sheet structure for removable application to a patient's foot, said sheet structure having interposed therein an integral bladder; an inlet for fluid inflation ol said bladder; and said sheet structure being adapted and said bladder being shaped to produce a non-shearing compressive force in the area ol the patient's first and filth metatarsal heads upon fluid inflation ol said bladder. The multi-layered sheet structure may comprise a first sheet and a second sheet, said first sheet forming the exterior ol said structure and said second sheet forming the interior ol said structure, said second sheet being more extensible than said first sheet. A padding layer ol ester foam, or the like, may also be incorporated into each sheet.
5 Claims, 2 Drawing Sheets
FIELD OF THE INVENTION
The present invention relates to wound healing devices. More particularly, the invention relates to a therapeutic foot wrap for application of positive pressure to the first and fifth metatarsal head and heel regions of a patient suffering diabetic ulceration and/or like wounds.
BACKGROUND OF THE INVENTION
An ulcer is commonly defined as a lesion on the surface of the skin, or on a mucous surface, manifested through a superficial loss of tissue. Ulcers are usually accompanied by inflammation and often become chronic with the formation of fibrous scar tissue in the floor region. Chronic ulcers are difficult to heal; they almost always require medical intervention and, in many cases, lead to amputation of the limb upon which they occur.
In general, ulcers may be attributed to any of a variety of factors reducing superficial blood flow in the affected region. Leg (including the foot) ulcers, in particular, are attributable to congenital disorders, external injury, infections, metabolic disorders, inflammatory diseases, ischaemia, neoplastic disorders and, most commonly, arterial disease, neuropathic disorders and venous insufficiency. Neuropathic and ischaemic ulcers commonly manifest in association with diabetes and, for this reason, are often referred to as diabetic ulcers. Although certainly not exhaustive, the table entitled Common Etiology of Leg Ulcers, highlights the frequency at which patients are placed at risk for the formation of this potentially devastating disease.
Neoplastic Disorders: Neuropathic Disorders:
Common Etiology of Leg Ulcers
Absence of valves, chromosomal disorders, Klinefelter's syndrome, connective tissue defects affecting collagen and elastic fibers, arteriovenous aneurysms, prolidase deficiency. Laceration, contact dermatitis, decubitus, inoculation (drug addiction), burns, cold, irradiation.
Viral, bacterial, fungal.
Diabetes mellitus, colonic stasis from sugar/
Vasculitus, pyoderma gangrenosum, rheumatoid arthritis, panniculitus. Peripheral vascular disease, embolus, scleroderma hypertension, sickle-cell anemia. Skin neoplasms, leukemia. Spina bifida, leprosy, diabetes mellitus, neoropathy syringomyelia.
Posture (prolonged standing, legs crossed, long legs), abdominal pressure (tumor, pregnancy), employment, physical activity (apathy, paralysis, osteoarthritis), effort (weight lifting), deep vein thrombosis (50% tibial fractures, 25% abdominal surgery, 25% myocardial thrombosis, 50% strokes), blood stasis, hemolytic anemias.
Perhaps as striking as the incidence of this disease, is the 60 magnitude of the resources dedicated to the combat of its occurrence. It is estimated that leg ulcers cost the U.S. healthcare industry in excess of $1 billion annually in addition to being responsible for over 2 million annual missed workdays. Unfortunately, the price exacted by ulcers 65 is not merely financial. Leg ulcers are painful and odorous open wounds, noted for their recurrence. Most tragic, dia
betic ulcers alone are responsible for over 50,000 amputations per year. As alarming as are these consequences, however, the basic treatment regimen has remained largely unchanged for the last 200 years. In 1797, Thomas Baynton of Bristol, England introduced the use of strips of support bandages, applied from the base of the toes to just below the knee, and wetting of the ulcer from the outside. Standard of care treatment for ulcers affecting the foot has developed little beyond prevention oriented approaches. When management of the underlying disease condition fails to prevent ulcer formation, debridement and occlusive bandaging is about the only remaining option. As discussed in more detail herein, versions of these therapies remain the mainstay treatment to this day and, clearly, any improvement is of critical importance.
As noted above, the most common causes of leg ulcers are venous insufficiency, arterial disease, neuropathy, or a combination of these problems. Venous ulcers, in particular, are associated with abnormal function of the calf pump, the natural mechanism for return to the heart of venous blood from the lower leg. This condition, generally referred to as venous insufficiency or venous hypertension, may occur due to any of a variety of reasons, including damage to the valves, congenital abnormalities, arteriovenous fistulas, neuromuscular dysfunction, or a combination of these factors. Although venous ulcers tend to be in the gaiter area, usually situated over the medial and lateral malleoli, in severe cases the entire lower leg can be affected, resembling an inverted champagne bottle.
Diabetic and arterial ulcers, in particular, are associated with degenerative disease resulting in progressively narrowed vessel lumen which, in turn, causes obstructed blood flow. These types of ulcers are frequently found at sites of localized pressure or trauma. The diabetic patient (neuropathic ulcers), who may also suffer arterial disease, will often have impaired sensation in the foot area and will therefore likely be unaware of repeated trauma. This exacerbates ulceration in the traumatized or pressure-bearing areas, commonly the first and fifth metatarsal heads and over the heel.
Clinical modalities for prevention of venous ulcers generally focus on the return of venous blood from the lower extremities to the heart. Mechanical prophylaxes are widespread in the art of prevention and are often referred to as foot pumps or wraps, leg pumps or wraps and sequential compression devices, all of which function to prevent deep vein thrombosis ("DVT"), a common precursor to venous stasis ulcers. An exemplary foot pump is commercially available from Kinetic Concepts, Inc. of San Antonio, Tex. under the trademark "PLEXIPULSE." An exemplary sequential compression device is described in U.S. Pat. No. 5,031,604 issued Jul. 16, 1991 to Dye ("Dye").
As generally described in Dye, mechanical prophylaxes for DVT prevention are directed toward the improvement of venous return. To this end, devices like that of Dye are adapted to take advantage of the naturally occurring valvular structure of the veins to squeeze the blood from a patient's limb. For instance, the trademark "PLEXIPULSE" device is adapted to intermittently compress the patient's plantar venous plexus, promoting the return of blood from the patient's foot upward and through the calf region. Likewise, and as generally described at column 2, lines 33 et seq. of Dye, leg compression devices are usually adapted to squeeze the patient's leg first near the ankle and then sequentially upward toward the knee. This milking-type sequence may or may not be performed on a decreasing pressure gradient, but is always designed to move blood from the extremity toward