Surgery – Endoscope – Having imaging and illumination means
Reexamination Certificate
2000-02-11
2002-07-02
Dvorak, Linda C. M. (Department: 3739)
Surgery
Endoscope
Having imaging and illumination means
C600S131000, C600S183000, C600S235000, C606S190000
Reexamination Certificate
active
06413208
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a medical instrument for endoscopic removal of the saphenous vein, having an elongated shaft which has at the distal end a spatula tip and in whose proximal region is arranged a laterally projecting handle; and further having an endoscopic optical system which has an eyepiece cup that is arranged at the proximal end of the instrument.
The present invention further relates to a method for endoscopic removal of the saphenous vein.
An instrument of the aforesaid kind is known from the company document “Endo World,” CHIR No. 4-D, 1997, published by Karl Storz GmbH & Co., Tuttlingen, Germany. An instrument of this kind is illustrated on page 3 of this document under the designation “optical retractor.”
The saphenous vein (vena saphena magna) is a long leg vein that runs on the medial (i.e. inner) side of the leg from the inside of the ankle along the lower leg and thigh to the groin.
The saphenous vein is often removed for use as a transplant in cardiac and vascular surgery. In conventional surgical methods for removal of the great saphenous vein, either a single long incision is made along the inner side of the leg, or several short incisions, separated from one another, are made. Using instruments (called “vein dissectors”) introduced through these incisions, the saphenous vein is detached from the surrounding connective tissue and its lateral branching vessels. The detached and isolated vein is then removed through the incision or incisions. This hitherto usual manner of removal through a single long incision or several separate incisions entails the risk, however, of injury to the medial lymph bundle and thus infection of the operative area.
The article “Minimally invasive, video-assisted vein harvesting for cardiac and vascular surgical procedures” by Lutz et al. (1997), in European Journal of Cardio-Thoracic Surgery 12, pp. 519-521, describes an alternative method for removing the saphenous vein, in which the vein is removed using minimally invasive techniques under endoscopic observation. For this purpose, only a single small (2-3 cm long) incision is introduced in the vicinity of the knee joint. Through this incision, the instrument cited initially is introduced upward along the thigh portion of the vein into the groin, and downward along the lower-leg portion of the vein to the inner ankle. The vein is thereby detached from connective tissue and lateral branching vessels, and the entire vein is pulled out through the single incision in the knee region. This endoscopic removal technique is gentle on the tissues, as compared to the earlier removal method described above, because only the one incision is required, and the patient's postoperative discomfort and the risk of surgical infection are much lower. In addition, removal using this newer method always takes place under endoscopic visual supervision.
The instrument known from the aforementioned German company document. “Endo World,” which is suitable for the procedure described above, has an elongated shaft that carries at its proximal end a laterally projecting handle and an eyepiece cup belonging to an endoscopic optical system. The shaft is configured from the proximal to the distal end—at which a narrow spatula tip, tapering in the distal direction and slightly curved, is configured—as an approximately kidney-shaped trough for external reception of an optical shaft of the endoscopic optical system, i.e. the endoscope shaft rests on the outside of the shaft in the trough. The endoscopic optical system, made up of the optical shaft and eyepiece with eyepiece cup, can be removed from the shaft by pulling the endoscopic optical system in the proximal direction off the shaft, through an attachment segment of the handle. The shaft of the medical instrument is approximately 30 cm long in order to be able to reach the ends of the vein from the single incision in the knee region.
With the known instrument, the handle is attached to the shaft in such a way that the shaft is widened in the region of the handle, i.e. the outer side of the instrument, facing away from the handle, has a step in the region of the handle extension.
In addition, the eyepiece cup is arranged at the proximal end of the shaft in such a way that the longitudinal center axis of the eyepiece cup runs as a straight-line coaxial extension of the longitudinal center axis of the instrument shaft, so that the eyepiece cup extends circumferentially beyond the shaft on all sides.
This configuration of the known instrument is, however, disadvantageous in the context of a surgical procedure for removing the great saphenous vein.
This is because in the endoscopic procedure for removal of the great saphenous vein, the instrument is introduced through the incision in the knee region and is pushed upward along the vein to the groin, and downward into the ankle region.
In order to allow the entire vein to be removed through a single incision, the entire length of the medical instrument must be utilized, since the instrument must be advanced from the knee into the groin and down to the ankle along the vein. Since the vein runs just beneath the skin, the shaft of the instrument must be advanced almost parallel to the skin surface, so that the segment of the shaft located outside the incision as the shaft is advanced along the vein must be pushed forward while being held as closely as possible against the leg.
With the known instrument, the fact that the attachment segment of the handle and the eyepiece, as described above, project laterally in the proximal region of the shaft that remains outside the body means that the instrument is considerably widened in its proximal region above the shaft on the outer side of the instrument that rests against the leg. This widening, however, prevents the instrument from lying close to the patient's leg, with the consequence that the spatula tip cannot be slid forward along the vein just beneath the skin surface. Such is the case, at least, when the instrument has already been advanced a long way into the operative area. Because of the widening of the instrument in the proximal region on the outer side facing away from the handle, it is thus almost impossible to guide the spatula tip deep into the operative area along the saphenous vein while still parallel to the skin surface. Instead, the spatula tip penetrates into deeper tissue and can thereby result in undesirable damage to uninvolved tissue. To eliminate this risk, the known instrument can be used only up to a certain insertion depth of the shaft into the operative area. A further disadvantage of the known instrument furthermore consists in the fact that with increasing insertion depth of the shaft into the incision, the camera connected to the eyepiece for observation of the operation through the endoscopic optical system is, beyond a certain insertion depth, in such close contact against the patient's leg that the camera, whose housing dimension transverse to the shaft axis is wider than the shaft itself, prevents parallel subcutaneous advancement of the instrument. The camera furthermore prevents the introduction of further auxiliary instruments into the incision. Handling of the known instrument is thus also made more difficult.
U.S. Pat. No. 5,667,480 also discloses an instrument and method for endoscopic removal of the saphenous vein in which the aforesaid disadvantages also exist, namely that the shaft is widened in the region of the handle attachment, and that the eyepiece is axially aligned.
U.S. Pat. No. 5,373,840 discloses a comparable instrument, having a handle protruding laterally from the shaft and having an integrated endoscopic optical system that transfers the observed image directly to a monitor. An eyepiece can also be provided in conventional fashion instead of the monitor, but there is no indication as to how the eyepiece would then be arranged.
Against this background, it is the object of the present invention to make available a medical instrument of the aforesaid kind which makes
Beyersdorf Friedhelm
Lutz Christoph
Schöllhorn Joachim
Dvorak Linda C. M.
Karl Storz GmbH & Co. KG
Ram Jocelyn
St. Onge Steward Johnston & Reens LLC
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