Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2000-01-27
2001-05-29
Kennedy, Sharon (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
Reexamination Certificate
active
06238370
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for dilating and restoring the lacrimal duct in the human eye, through which lacrimal fluid flows from the eye into the nasal cavity.
2. Description of the Prior Art
In the human eye, lacrimal fluid serves not only to moisten the cornea surrounding the eye in the front zone and hence to avoid desiccation of the eye but has also a cleaning effect, for instance by washing out of the eye, so to speak, foreign bodies, bacteria or any other contaminants by means of the lacrimal fluid. Excess lacrimal fluid flows through the lacrimal duct, which is present on the nasal side at the eye, into the nasal cavity where the lacrimal fluid is evaporated and absorbed by the respiratory air and serves, for instance, to moisten the respiratory passages.
In cases where the lacrimal duct is partly or completely obstructed by internal adenoid infection or deposits, the natural outflow of lacrimal fluid is at least hindered or stopped completely. In such cases lacrimal fluid collects in the eye, preferably in the zone of the lower eyelids, with the formation of small stationary lakes of lacrimal fluid, so to speak, where contaminants may collect which constitute sources of infection for the eye cavity.
Such cases of insufficient outflow of lacrimal fluid occur, in particular, on elderly people, which can be treated either by medication and/or by surgery; in surgical operations the lacrimal duct is laid bare again even though it has so far not been possible to ensure that after the operation the lacrimal duct will not be obstructed again. Moreover, a surgical operation imposes a serious strain on the patient, which causes pain and particularly a long-lasting healing process and convalescence of the eye so that the patent's vision is restricted, at least temporarily.
SUMMARY OF THE INVENTION
The present invention is based on the problem of defining a device for dilating and restoring the lacrimal duct on the human eye, through which lacrimal fluid flows from the eye into the nasal cavity, of such a type that the strain on a patient to be treated can be substantially so reduced that an operation to be performed with the of the present invention device can take place in the outpatient department, without exposure of the patient to long-lasting complicated healing processes on the lacrimal duct to be treated as a result of traumatic irritation. The device should furthermore ensure that after performance of the operation the unrestricted function of the lacrimal duct will be restored and that moreover a repeated obstruction of the lacrimal duct will be largely precluded.
In accordance with the invention the device for dilating and restoring the lacrimal duct on the human eye, through which lacrimal fluid flows from the eye into the nasal cavity, is a cannula system presenting the following individual components:
A first hollow canal is provided on its distal end with at least one longitudinal cut. A guide, which is preferably configured as a hollow cannula in its turn, passes through the first hollow cannula and dilates the distal end of the first hollow cannula over which the longitudinal gap extends. Above the outside contour of the first hollow cannula a hollow body is provided, equally at the distal zone thereof, which surrounds the outside contour of the first hollow cannula and which is mounted thereon for displacement.
Finally, a second hollow cannula is provided which can be pushed over the first hollow cannula and which extends up to the end on the proximal side of the hollow body mounted on the fist hollow cannula, hence locking the second below cannula so as to prevent axial sliding on the proximal side.
The aforementioned individual components constitute a cannula system which allows firstly for a penetration into the lacrimal duct through the opening of the lacrimal duct present at the eye zone on the nasal side, and for dilating the obstructed lacrimal duct. An optical system for observation is preferably guided through the internal canal of the guide, and an irrigation canal is provided so that the operation of introducing the cannula system into the lacrimal duct can be visually observed and controlled on an appropriate transmission monitor, with the irrigating or through-drainage liquid exposing, on the one hand, the field of vision ahead of the tip of the cannula and supporting, on the other hand, the operation of penetration inside the lacrimal duct.
The device excels itself, however, particularly by the provision that a hollow body is provided on the distal end zone of the cannula system, which can be selectively introduced, together with the cannula system, into the lacrimal duct and can be fixed there. The cannula system is so designed that the hollow body, which is pushed onto the outer periphery of the first hollow cannula in the distal end zone, is fixed both in a direction towards the distal end and in a direction towards the proximal end of the cannula system. The proximal fixation is realized by means of the second hollow cannula which is pushed over the first cannula and which presents a bearing surfare on the distal side, against which the hollow body pushed onto the first hollow cannula bears by its end on the proximal side. The first hollow cannula is provided on the distal tip with a longitudinal gap for fixing the hollow body on the distal end of the cannula system, and presents preferably moreover an internal volume which tapers towards the distal tip. When the guide is inserted into the first hollow cannula the distal tip of the guide hits against the narrowing conical internal contour of the first hollow cannula, pressing the halves of the cannula apart on the distal tip so that the outer diameter of the first hollow cannula will be enlarged on the distal zone. The enlargement of the outer diameter is envisaged in such a way that the hollow body, which is seated on the first hollow cannula, cannot be pushed beyond the tip of the first hollow cannula. In this manner, the hollow body is locked and prevented from sliding on the first hollow cannula both on the distal and the proximal side. In this condition, the inventive cannula system of the present invention is introduced into the lacrimal duct to be treated until a desired position is reached inside the lacrimal duct so that, for instance, the hollow body, which is preferably configured as a metal spiral, will extend in the longitudinal direction over the entire lacrimal duct. In this position, the internal guide is removed from the first hollow cannula, which causes the retraction of the distal dilation to the normal diameter of the hollow cannula. In a further step, the first hollow cannula is retracted relative to the second hollow cannula, while the hollow body, which is seated on the first hollow cannula in the form of a metal spiral, remains at the envisaged site inside the lacrimal duct, specifically since the hollow body is locked by the second hollow cannula and protected from sliding on the proximal side, which may be induced when the first hollow cannula is retracted. Only upon the complete removal of the first hollow cannula from the second hollow cannula it is possible to remove the second hollow cannula as well from the lacrimal duct so that merely the hollow body introduced into the lacrimal duct will fixedly be retained therein.
Immediately upon removal of the first hollow cannula, it is moreover possible to introduce an observation endoscope through the second hollow cannula, which is placed in the lacrimal duct, for checking the hollow body for correct seating in the lacrimal duct. In the event of a subsequent correction the first hollow cannula must then be inserted through the second hollow cannula into the lacrimal duct and subsequently the guide must be introduced into the first hollow cannula so that the hollow body will be locked in both directions for protection from sliding along the hollow cannula. In this state the hollow body must be re-adjusted relative to the lacrimal duct so that the
Hassel Jörg
Heske Norbert
Neuhann Thomas
Antonelli Terry Stout & Kraus LLP
Kennedy Sharon
Serke Catherine
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