US2192699A - Surgical instrument - Google Patents

Description

March 5, 1940. c. sToRz 2,192,699

SURGICAL INS TRUMENT Filed April i, 1938 INVENTOR. C/fiflZf-S Tapz ATTORNEYS,

Patented Mar. 5, 1940 UNITED STATES PATIENT. OFFICE SURGICAL INSTRUMENT Charles R. Storz, St. Louis, Mo.

Application April 1, 1938, Serial No. 199,381

cornea to a cornea which has lost its transparency.

The eye from which the normal section is takenmay be called the donor eye, and that which receives the normal section may be called the host eye. The cornea of the eye is convex in shape and is composed of relatively tough tissue. The anterior chamber immediately behind it contains the aqueous humor.

In the corneal transplant operation a section is removed from the host eye and replaced with a section from the donor eye. It is highly important for the transplanted section to be the same size and shape as the removed section, so that the transplanted section will accurately fit the opening in the host cornea. The edge-walls of the opening and of the new section should be tapered inwardly in the direction from front to back, so that the new section will not fall inwardly. This is especially important because it is undesirable for the gut or other suture by which the new section is held in place to pass entirely through any part of the cornea and particularly because penetration of the new section should be entirely avoided. In securing the new section in place, therefore, the gut is secured to the host cornea beyond the edges of the opening, as by threading'it into such cornea but without penetrating the posterior layers of the cornea, and stretches of the gut are arranged to overlie the new section, to hold it inwardly. The taper of the edgewalls of the opening and of the new section is thus relied upon entirelyto prevent the new section from moving inwardly.

In previous methods of performing this operation the section to be removed is marked, as with a trephine when the section is to be in the shape of a disk, or .by marking with a pair of parallel knives two pairs of shallow cuts, with one pair at right angles to the other, to outline a square section. The gut is then threaded in a suitable pattern, but left with considerable slack in the stretches which will eventually overlie the transplanted section. Then, holding these slack stretches of gut aside, the cornea section to be removed is cut by hand, either with a knife or with scissors. This cutting requires extremely careful work, for as has been pointed out the opening must have inclined edgewalls and must be of such regular shape that a duplicate section can be cut from a normal cornea to accurately fit that opening. When the opening hasbeen made, a section from the donor eye is-transferr-ed (01. 128-303) to the opening in the host eye, and the gut is then drawn tight and tied.

It is the object of my invention to provide an instrument which will be suitable for cutting a disk from a cornea; will accurately duplicate such disk when used to out a section from another cornea, so that the disk from one cornea will be of identical shape and size as the opening left by the section cut from the other cornea; and will cut in such a way that the edge-walls of the disk and opening will be tapered, and the disk edge-wall will accurately mate with'the edgewall of the opening which is to receive it.

An instrument embodying my invention may be in the form of a hand punch with two pivoted jaws. The lower jaw is relatively small in cross section so that it can be inserted under the cornea through an incision near the edge thereof. It has an opening near its end, with sharp upper edges and of a size adapted to receive the desired transplant disk.. The upper jaw carries a punchmember which has a spherical end of slightly larger diameter than the diameter of the opening in the lower jaw and is so located that as the jaws are closed the spherical end approaches the opening in the first-named. jaw axially thereof. When such an instrument is used, the central portion of the spherical surface first engages the cornea and deforms it by. pressing the engaged portion downward to reverse its curvature. As the sphere is pressed further toward the lower jaw it co-operates with the edges of the opening in such lower jaw to cut away the deformed corneal portion while so deformed. When the sphere is then retracted, the cut section or disk of the cornea resumes its normal curvature and condition. In the resulting disk, the edge-walls are tapered. I believe this is because the deformation which exists during the cutting stretches the inner layers of the disk to a greater extent and at different locations than any stretching which occurs in the outer layers. In consequence, when the disk returns to its normal condition such inner layers have a smaller diameter than'do the outer layers.

The accompanying drawing illustrates my invention:

Fig. 1 shows a pair of punch-pliers embodying my invention;

Fig. 2 is an enlarged side elevation of the jaws of such punch-pliers with parts broken away to show details of construction;

Fig. 3 is a transverse sectionon the line 3--3 of Fig. 2; and

Fig. 4 is a somewhat idealized sectional view of a portionof a cornea'into which a new section has been transplanted by the use of an instrument embodying my invention.

The punch-pliers shown in the drawing have a pair of jaws l0 and H pivoted to each other by the screw l2. A handle l3 integral with the jaw 10 extends rearwardly from its pivot point with a stretch M of considerable length that is parallel with the jaw l0 and is straight. This stretch it leads into an outwardly curved portion l5, which in turn leads to a portion 15 of reverse curvature which is adapted to be grasped by the hand of the operator. A similar handle I? inte gral with the jaw I l extends rearwardly from its pivot point. The two jaw-handle members are crossed at the pivot point so that when the handles are pressed together, the jaws move together. To hold the handles in normally open position, the portion l5 of the handle [3 has secured to it a leaf spring 58 which extends forwardly away from the stretch [4 into engagement with the base of a groove in the straight stretch of the handle H.

The jaw i s is made of a hard material, such as tool steel, and is desirably of relatively small cross-section. It is'tapered smoothly from near its pivot point and at its end isprovided with an opening 28 whose axis extends perpendicular to its inner face. Desirably, the walls of the open,- ing flare outwardly from such inner face toward the lower face, so that they are frusto-conical, for this provides a sharp edge where such openingwalls intersect the inner face of'the jaw Ill.

The upper jaw ii, at a location similar to that of the opening 2! in the jaw it is provided with a ball-socket 22. The center of the socket 22 is so located that when the jaws if! and ll are in fully closed position the socket center lies on the axis of the opening 26. A punch member or plunger 25 is mounted in the socket 22 by being provided at its upper end with a. ball 26 adapted to fit within such socket 22. Shortly below the ball 2b the plunger 25 is provided with laterally projecting shoulders 21. A leaf spring 28 which is secured to the base of the jaw H, extends forwardly, and has a bifurcated forward end which loosely embraces the plunger 25 immediately be low the shoulders 27 and presses upwardly against such shoulders to hold the ball 26 in the socket 22. The lower end of the plunger 25 has an enlargement 29 which provides a hemispherical end for suchplunger. The sphere diameter is slightly larger than the smallest diameter of the opening 29, so that such sphere will not pass through the opening 2E9; For example, when the smallest diameter of the opening is 5 mm., which I consider to be a suitable size, the sphere diameter may be from 5.5 to 6 mm.

The axis of the plunger 25, in the closed position of the jaws, is substantially perpendicular to the inner face of thejaw is so that as the jaws are closed the spherical surface of such plunger 25 approaches the cutting edges at the intersection of the Wall of the opening 25 with such inner face at substantially the-same rate and from substantially the same relative direction at all points around such edge. The plunger 25, by reason of its ball and socket mounting in the jaw H has a limited universal movement so that it is capable of centering itself in the opening 2! throughout the range of cutting movement as the jaw approaches closed position.

- It will be noted that the outer faces of the straight stretches of the handles 13 and Il'-- identified by the reference numeral M of the handle l3-lie between the parallel planes of the outer surfaces of, the jaws l0 and II when such jaws are in closed position. This makes it possible during an operation for such plane of the jaw III to lie quite close to the face of the subject.

In using an instrument of this sort, an incision ismade near the edge of the cornea of the eye which is to become the host, and the jaw i0 is inserted through that incision until the opening 2!] lies beneath that portion of the cornea which it is desired to remove. The jaws are then closed, and the spherical surface of the plunger 25 engages the convex outer surface of the cornea, pressing it inwardly into the opening 28 and reversing its curvature. The jaw-closing operation is continued, with sufficient pressure applied through the handles [3 and H, to cut through the cornea tissue. The disk which is thus cut from the cornea will remain in the opening 2!] and may be withdrawn with the jaw it) through the incision through which the jaw H] was originally inserted. The instrument may also be used, either before or after the operation on the host eye, to out a disk from the donor eye. This latter disk will be of substantially identical size with the disk removed from the host eye and will therefore accurately fit the opening in the host cornea. The edge-walls of the opening and of the disk to be inserted will be tapered, and will mate one with the other. An accurate fit will thus be ob.- tained and the interfitting tapered walls will permit the transplanted disk to be held in place by being merely held against outward movement. The taper at the edge-walls is mainly due to the fact that when cutting occurs, the inner layers of the cornea are stretched to a materially greater extent than the outer layers, so that return to normal draws such inner layers to a smaller diameter than the outer layers. I believe it is also in part due to the way in which the cutting is done. As the reversion of. curvature of the corneal section begins, during the closing of the jaws, the sharp edge of the opening 28 tends to hold the immediately adjacent layers against movement. At the outer layers, hOVV6VcT, the cornea is simply laid against the spherical surface and tends to move with that surface. Those outer layers, therefore, tend to be moved radially inwardly with respect to the edge supporting the inner layers. The cutting begins at those inner layers, which then tend to contract to normal condition, and thus assist this relative movement of the outer layers, so that from. the point of view of the normal relationship, the cut at the outer layers is radially outwardly beyond the cut at the inner layers.

I claim as my invention:

1. A corneal transplant punch, comprising a pair of jaws relatively movable toward each other, a punch member carried by one of said jaws Which presents a convex surface toward the other jaw, such other jaw being provided with an opening adapted to receive a central portion of said surface and to have its edges engaged by a surrounding portion of said surface, said punch member being mounted for limited universal movement .With respect to the jaw which carries it.

2. A corneal transplant punch as defined in claim 1, in which the convex surface is spherical.

3. A punch adapted to cut from a cornea a circular section-of predeterm ned size and with its edges tapering from the convex toward the concave side thereof, comprising a pair of jaws 75 relatively movable toward each other, a socket in one of said jaws, a punch member having its end received in such socket, means for holding such end in such socket, a hemispherical surface on the other end of said punch member, the other jaw of said pair being provided with an opening the intersection of whose walls with the inner jaw-face forms a circle of slightly smaller diameter than said hemispherical surface, the relationship of said parts being such that the centers oi said socket and said hemispherical sur face lie substantially on the axis of said circle.

4. An instrument for excising corneal transplant sections, comprising a member for engaging the concave posterior side of a cornea and provided with a hole defined by sharp edges, means including a member having a smoothly curved convex surface for reversing the curvature of a corneal portion located centrally of said hole to carry a central part thereof into the open end of said hole, said means being adapted to sever such deformed corneal portion from its surrounding tissue.

5. In an instrument for excising corneal transplant sections, means including a member having a smoothly curved convex surface for reversing the curvature of a portion of said cornea to stretch its inner layers, and means for severing such portion from surrounding tissue while so deformed, whereby upon the return of such parts to normal shape the edge-walls of the resulting cut will be tapered.

6. An instrument for excising corneal transplant sections, comprising a member adapted to be inserted through a slit near the edge of a cornea to lie behind its posterior surface, said member being provided with an opening disposed to lie axially of said cornea, a second member having a smoothly curved convex surface of slightly larger projected area than said opening and adapted upon movement toward said opening and against the convex anterior surface of the cornea to cause said cornea to be laid against such curved surface to reverse the curvature of said cornea and stretch its inner layers, the edges of said opening being adapted to cut through said deformed portion of said cornea starting at such stretched inner layers, whereby to cut a corneal section of predetermined size which in normal condition has its edges tapered from its anterior toward its posterior surfaces and is adapted to fit an opening similarly out in another cornea, and means for moving said second member substantially axially of said opening in said first member.

'7. An instrument as defined in claim 6, in which the opening in said first member is circular and said curved surface is spherical and of a diameter approximately from ten to twenty percent greater than the diameter of such openmg.

8. An instrument as defined in claim 4 in which the opening is of approximately 5.0 mm. diameter and the curved surface is spherical on a diameter of approximately from 5.5 mm. to 6.0 mm. diameter.

CHARLES R. STORZ.

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