EP1648315A2

EP1648315A2 - Obturator tip

Info

Publication number: EP1648315A2
Application number: EP04717484A
Authority: EP
Inventors: Peter O'heeron
Original assignee: HEERON PETER O; O'Heeron Peter; Neosurg Technologies Inc
Current assignee: CooperSurgical Inc
Priority date: 2003-08-01
Filing date: 2004-03-04
Publication date: 2006-04-26
Also published as: EP1648315A4; WO2005016415A2; WO2005016415A3

Abstract

A trocar is disclosed which includes a housing assembly and a cannula assembly attached to the housing assembly to define an axial bore therethrough. The trocar further includes an obturator which slidably engages the axial bore defined by the cannula assembly. The obturator includes a shaft having a piercing end for insertion into a patient and a handling end for gripping by a surgeon. Attached to the piercing end of the shaft is a piercing tip having an upper face and a lower face which taper away from the shaft to form a non-conical, blunt head. The piercing tip further includes wing elements located on opposite sides of the piercing tip between the upper and lower faces. Each wing element of the invention having one or more sloped surfaces designed to separate tissue.

Description

TITLE: Obturator Tip INVENTOR: Peter T. O'Heeron

FIELD OF THE INVENTION

[0001] The present invention relates generally to surgical instruments and, more particularly, to an obturator for use in conjunction with one or more trocars for penetrating an anatomical cavity of a patient to provide communication with the cavity during a surgical procedure.

BACKGROUND OF THE INVENTION

[0002] A trocar is a surgical instrument that is used to gain access to the abdominal cavity. A trocar generally comprises two major components, a cannula and an obturator. In order to penetrate the skin, a small incision is made by the surgeon where the trocar is to be inserted. The distal end ofthe trocar is then inserted into the tissue. The obturator has a point or cutting edge at its distal end. By applying pressure against the proximal end ofthe obturator, the point is forced through the tissue until it enters a target location, such as the abdominal cavity. The cannula is inserted through the perforation made by the obturator and the obturator is withdrawn, leaving the cannula as an access to the abdominal cavity.

[0003] Because trocars typically include sharp blades, inadvertent tissue or organ puncture is a concern. To address this, trocars including a safety shield on the obturator were developed to lessen the possibility of unintentional puncture. The shield is biased in an extended position to cover the piercing tip ofthe obturator. When the surgeon desires to penetrate tissue with the trocar, the safety shield retracts and exposes the penetrating tip. The shield remains in the retracted position so long as pressure is continuously applied. In theory, when the surgeon fully punctures the body wall, the pressure is relieved and the safety shield returns to its extended position covering the penetrating tip. Unfortunately, such devices are not always effective. First, the external shield tends to provide an additional impediment to insertion, thus requiring greater incision force and compounding the risk of follow through injury. Second, the force ofthe safety shield passing through the skin tissue often results in tearing and other damage at the incision point. In addition to needlessly increasing the size of a surgical wound, this also tends to compromise the foundation ofthe cannula and may lead to undesirable leaks of fluids and gases during the operation. Third, many physicians complain that the recoil from the safety shield at almost the same moment as the trocar insertion tends to disorient them as to the precise location ofthe trocar after insertion. This results in wasted time and effort to reorient the trocar and greater risk of internal damage during the period of reorientation.

[0004] Certain trocars, for example, as disclosed in U.S. Patent Nos. 5,817,061 to Goodwin, and 5,591 , 192 to Privitera have employed a pair of blunt edged blades or tissue separators which are located on the tip of the trocar to facilitate the penetration or dissection of tissue.

[0005] Both ofthe trocar assemblies disclosed inU.S. Patent No. 5,817,061 to Goodwin and U.S. Patent No. 5,591,192 to Privitera are manufactured and sold by Ethicon Endo- Surgery, Incorporated. It is believed that trocars as described in the '061 and '192 patents have encountered significant problems since the tip ofthe obturator may be prone to failure. In particular, the tip ofthe trocars disclosed in the '061 and '192 patents are believed to have experienced incidents of snapping off during the insertion ofthe trocar.

[0006] There remains a need for an obturator tip capable of piercing and separating tissue so as to lessen the risk of follow through injury.

SUMMARY OF THE INVENTION

[0007] An obturator in accordance with the present invention comprises a shaft which slidably engages the axial bore defined by the cannula assembly of a trocar. The shaft has a distal end for insertion into a patient and a proximal end for gripping by a surgeon. The distal end has a non-conical, blunt head capable of dividing tissue as opposed to cutting tissue. The distal end ofthe shaft ofthe obturator includes a tip having an upper face and lower face which have flat and gently sloping bevels from the shaft portion toward the distal end to assist in the insertion. The distal end also includes two flat side faces interposed between the upper and lower flat faces. The side faces also slope from the shaft to the distal end. The distal end having a glide tip which is interposed between the upper and lower flat faces in a plain substantially equidistant between the upper and lower faces.

[0008] The tip ofthe obturator ofthe present invention comprises an insert blade residing partially within the tip and protruding outwardly away from the shaft portion of the obturator. The blade having a non-conical, blunt head portion and two wing elements located on opposing sides of the blade. In one embodiment, the wing elements have upper and lower surfaces designed to carefully and efficiently separate tissue during a procedure. In one embodiment, the upper surfaces of the wing elements have a downward slope away from the distal end of the obturator and terminate distally at or below the midpoint ofthe thickness ofthe blade.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing; it being understood that the drawings contained herein are not necessarily drawn to scale; wherein:

[0010] Figure 1 is a prospective view of one embodiment of a trocar in accordance with the present invention.

[0011] Figure 2 is an enlarged prospective view of the tip of an obturator of one embodiment ofthe present invention.

[0012] Figure 3 is a front elevation view ofthe tip of an obturator of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] With reference to Figure 1, a trocar (5) in accordance with the present invention comprises a housing assembly (10) to which is attached a cannula assembly (20). The cannula assembly (20) comprises a hollow tube, and when attached to the housing assembly (10), a bore is defined through the trocar (5).

[0014] Still with reference to Figure 1, a trocar (5) in accordance with the present invention also includes an obturator (30) having a shaft (31) with a handling end (32) and a piercing end (33). hi one embodiment, an arcuate-shaped cap (34) is attached to the handling end (32) ofthe shaft (31) to facilitate insertion and maneuvering ofthe obturator assembly (30) by a surgeon. A piercing tip (35) is attached to the piercing end (33) ofthe shaft (31). The obturator (30) slides in the bore defined by the combination of the housing assembly (10) and cannula assembly (20).

[0015] While the shaft (31) ofthe obturator assembly (30) is preferably formed from a stainless steel material, those skilled in the art will appreciate that the obturator shaft may be formed from a variety of suitable materials. With reference to Figures 2 and 3, an obturator tip (30) in accordance with the present invention is shown. Tip (35) comprises an upper face (36A) and a lower face (36B). The upper face (36A) and lower face (36B) are flat and slope or taper away from the shaft (31) toward the distal end ofthe obturator. Tip (35) also comprises side faces (38L and 38R), which are flat and between upper and lower faces (36A and 36B). In one embodiment, side faces taper or slope away from shaft (31) toward the distal end (33). [0016] The body (36) ofthe piercing tip (35) partially houses an insert or molded blade (37). The blade (37) comprises a blunt, non-conical head (38) and two wing elements (39A and 39B, respectively) which protrude outward from the body (36) ofthe piercing tip (35). Each ofthe wing elements (39A and 39B, respectively) has an upper surface (40 A) and a lower surface (40B). In one embodiment, the wing elements are located between the upper face (36A) and lower face (36B) of the body (36) and are spaced approximately 180 degrees apart. The blade (37) may be fabricated from metal or a hard plastic material.

[0017] In one embodiment, the blade ofthe present invention has a thickness (t) and a longitudinal axis (A). In one embodiment, the upper surfaces of each wing element are beveled such that they slope downwardly away from the distal end ofthe obturator. In one embodiment, the sloping upper surface ofthe blade terminates distally at or above the longitudinal axis ofthe blade. In one embodiment, the longitudinal axis (A) of blade (37) is located at the center point ofthe thickness (t) ofthe blade (37). Thus, the first surface of the blade slopes downwardly until it terminates distally at or below the midpoint ofthe thickness ofthe blade.

[0018] While the piercing tip (35) may be removably attached to the piercing end (33) of the shaft (31) ofthe obturator (30), the piercing tip may also be formed on the piercing end ofthe shaft such that the obturator is a monolithic piece.

[0019] The rounded end (38) ofthe obturator tip, as well as the beveled wing elements (39 A and 39B), respectively, function to divide tissue and muscle as opposed to cutting tissue and muscle. The upper and lower flat sloping faces (36 A and 36B) permit the tip (33) to be inserted into the patient relatively easily, and the sloping surfaces ofthe wing elements also aid in the insertion of the tip. In short, the rounded end (38) of the obturator tip and the sloped surfaces of the wing elements work in combination to prevent injury to the patient during a procedure. It should also be noted that the lower surfaces ofthe wing elements may slope in an upwardly direction. In one embodiment, the lower surfaces ofthe wing elements slope upwardly toward the rounded end ofthe obturator tip and terminate distally at or below the midpoint ofthe thickness ofthe blade.

[0020] An obturator having a tip in accordance with the present invention has a number of advantages over prior art obturators. It can be used on the initial penetration ofthe patient when the location of a vital obstruction may not be known, and it eliminates cutting of tissue and muscle as well as the trauma and recovery time resulting therefrom. No shielding mechanism is required with the obturator tip of the present invention, resulting in reduced costs. In short, the obturator tip ofthe present invention creates a smaller wound than a cutting blade, which results in quicker healing and better fascia fixation ofthe cannula. Finally, use of an obturator tip in accordance with the present invention results in dilation of the wound track instead of cutting of the wound track, which reduces the risk of herniation.

[0021] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications ofthe disclosed embodiments, as well as alternative embodiments ofthe invention, will become apparent to persons skilled in the art upon reference to the description ofthe invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope ofthe invention.

Claims

PATENT CLAIMSI claim:

1. An obturator tip for use with a trocar, said obturator having a distal end, a proximal end, and a shaft therebetween, said tip comprising:

upper and lower flat faces which slope from said shaft of said obturator toward said distal end of said obturator;

substantially flat side faces positioned between said upper and said lower faces, said flat side faces sloping from said shaft toward said distal end of said obturator; and

an insert or molded blade residing partially within said tip and protruding outwardly away from said shaft, said blade having a non-conical, blunt head portion and two wing elements located on opposing sides of said blade, said wing elements having upper and lower surfaces, said upper surface sloping downwardly away from said distal end of said obturator.

2. The obturator tip of claim 1 , wherein said insert blade has a longitudinal axis and said upper surface of said insert blade terminates distally at or below said longitudinal axis.

3. The obturator tip of claim 2, wherein said longitudinal axis is located half-way between said upper and lower surfaces of said blade.

4. The obturator tip of claim 1, wherein said insert or molded blade is fabricated from metal.

5. The obturator tip of claim 1, wherein said insert or molded blade is fabricated from plastic.

6. The obturator tip of claim 1 , wherein said distal end of said obturator comprising a handling member shaped to define a grasping portion.

7. An obturator tip for use with a trocar, said obturator having a distal end, a proximal end, and a shaft therebetween, said tip comprising:

substantially flat side faces positioned between said upper and said lower faces, said flat side faces sloping from said shaft toward said distal end of said obturator;

an insert or molded blade residing partially within said tip and protruding outwardly away from said shaft, said blade having a non-conical, blunt head portion and two wing elements located on opposing sides of said blade, said wing elements having upper and lower surfaces, said upper surface sloping downwardly away from said distal end of said obturator; said blade having a longitudinal axis located half-way between said upper and lower surfaces of said insert blade, said upper surface of insert blade terminating distally at or below said longitudinal axis.