Surgery – Instruments – Suture retaining means
Reexamination Certificate
1997-03-14
2002-12-31
Gilbert, Samuel G. (Department: 3736)
Surgery
Instruments
Suture retaining means
C128S898000
Reexamination Certificate
active
06500194
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the treatment of stress urinary incontinence “SUI,” and, in particular, to improved methods and surgical devices for the surgical treatment of SUI in females. The devices disclosed herein are additionally useful in a wide variety of other surgical procedures.
Genuine stress incontinence is the involuntary loss of urine due to a sudden rise in intra-abdominal pressure. It has been estimated that between 40% and 50% of young, healthy nulliparous women admit to occasional mild stress incontinence; however, at least 80% of stress incontinence patients are in the perimenopausal age group and are multiparous. Raz
3
has suggested that the female urethral continence mechanism is dependent on the interaction of four urethral factor: urethral closing pressure, urethral length, urethrotrigonal anatomy, and urethral reception of intra-abdominal pressure.
The urethral closing pressure is predominantly a result of the interaction of smooth and striated muscle sphincter activity, but there is also some contribution by nonmuscular urethral factors such as the submucosal vascular plexus, the elastin and collagen content of the urethral tissues, and a sphincter like effect of the mucosa. There has been considerable diversity of opinion regarding the anatomic structure and the innervation of the urethral sphincters, and a variety of views have been expressed in the literature.
Lapides and associates have stressed the importance of urethral length in the maintenance of continence in the female. However, although it certainly interacts with other factors to contribute to continence, a short urethra alone will not produce incontinence. Urethral length varies considerably in normal women, and women with proven genuine stress urinary incontinence do not invariably have urethral shortening.
Urethrotrigonal anatomy, which can be demonstrated by lateral cystourethrography, should fulfill certain criteria. The bladder base should lie above the level of the inferior ramus of the symphysis, and with straining should not descend more than 1.5 cm. There should be a normal urethrotrigonal alignment with an angle normally less than 100 degrees, and the urethral axis should be approximately 35 degrees from the vertical. In the hypermobile situation loss of all of the normal anatomic features may occur, a radiologic finding that correlates with the clinical finding of cystourethrocele. However, clinical experience has shown that the coexistence of cystourethrocele and incontinence does not predict that the incontinence is of a genuine stress variety.
The transmission of intra-abdominal pressure to the intra-abdominal portion of the proximal urethra is also reported to be important in the maintenance of continence. This is a passive phenomenon, and is the result of the normal anatomic configuration just described. Whenever there is a rise in intra-abdominal pressure during such stresses as coughing or straining, the pressure is transmitted not only to the bladder but also to the proximal urethra, with resultant increase in the closing pressure, and prevention of leakage. If the urethral axis is altered, rotational descent will drop the proximal urethra and bladder base from its intra-abdominal location, and will obviously impair such pressure transmission.
A wide variety of operations have been used to correct this condition, generally involving the principles of elevating the bladder neck anteriorly and/or elongating and narrowing the proximal urethra. Two of the most popular operations today for female stress incontinence are the Marshall-Marchetti-Krantz and Birch vesicourethropexies. The Marshall-Marchetti-Krantz technique has at least an eighty-five percent success rate, against which other operative success rates must be measured. Recently, the Pereyra operation and its modifications have enjoyed some popularity, but less than basic techniques.
Notwithstanding the foregoing, however, there remains a need for an improved treatment for SUI. Preferably, the treatment is as noninvasive as possible under the circumstances, and will eliminate or minimize hospitalization and the use of general anesthetics. In addition, there remains a need for improved medical instrumentation such as drill guides and suture passers for use in connection with SUI treatment and other medical procedures.
SUMMARY OF THE INVENTION
There is provided in accordance with one aspect of the present invention a drill guide for directing a drill bit at a selected site on a bone. The drill guide comprises a housing, and at least two chambers extending axially within the housing. Each of the chambers has an opening at the distal end. A plunger is provided in each of the chambers, each plunger axially movable from a first retracted position to a second extended position. A probe is mounted on the distal end of each of the plungers, and adapted for retraction within the open end of the chamber and extension outside of the open end of the chamber. In a simplified embodiment, each of two or more probes is axially movably disposed within the housing, without the use of a distinct plunger. A drill guide channel extends axially through the housing, within a plane parallel to the plane joining the axes of the first and second chambers, and in between the axes of the first and second chambers.
Preferably, one or both of the plungers is provided with a releasable lock for releasably retaining the plunger in the retracted position, thereby minimizing the likelihood of accidental needle sticks. The preferred probe comprises a hypodermic needle or a sharpened solid wire. In a two probe embodiment, the axes of the first and second probes are separated by a distance within the range from about 5 mm to about 15 mm. Preferably, the axis of the drill guide channel is approximately equidistant from the axes of each of the probes.
In accordance with another aspect of the present invention, there is provided an alternate embodiment of a drill guide for use in locating drill sites in a patient's body. The drill guide comprises a body, a handle connected thereto, and one or more bores extending through said body. Each bore has an opening at a distal end. A probe is provided in each bore, the probe being axially movable from a retracted to an extended position. A drill guide bore, which may also act as one of the probe bores, extends axially through the body. A suture slot extends from outside of the body to the drill guide bore along the length of the body. Serrations are provided on the distal end of the body, aiding in maintaining the opening of a drilled hole. In a two probe embodiment, the axes of the probes are separated by a distance of about 5 to 10 mm. Preferably, the probes of this embodiment are a unitary element, such as a wire or needle. Further, it is desired that the drill guide bore and any probe bores lie in a line perpendicular to the longitudinal axis of the body.
In accordance with the further aspect of the present invention, there is provided a method of positioning a drill guide over a drilling site on bone, comprising the steps of providing a drill guide of the type having a housing, at least two axially extendable probes within the housing, and a drill guide extending through the housing. A first probe is extended from the retracted position to the extended position, and advanced through the tissue until it contacts a bone. The second probe is thereafter extended from the retracted position to the extended position, until the second probe contacts the bone. If the first extension of the second probe does not result in a contact, both probes are retracted within the housing, and the drill guide is translated along the sagittal or other axis. The first probe is thereafter reextended and the foregoing steps are repeated until both the first and second probes contact the bone.
In accordance with another aspect of the present invention, there is provided a method of installing a bone anchor in a bone, utilizing the drill guide defined above. In accordance with the installation method
Benderev Theodore V.
Legome Mark J.
Naves Neil H.
Gilbert Samuel G.
Sci-Med Life Systems, Inc.
Testa Hurwitz & Thibeault LLP
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