Flexible endoscopic surgical port

Abstract: A flexible endoscopic surgical port comprises a trocar tube or cannula (62,142) made partially or entirely of flexible material which can be inserted into a body wall at an intercostal location to allow the insertion and manipulation of endoscopic surgical instruments within the thoracic cavity. The surgical port includes a hollow tubular body which is inserted through an intercostal opening in the body wall extending into the thoracic cavity with an annular flange (68,148) at one end of the tubular body projecting radially outward and engaging the body wall adjacent to the opening. The flange is able to flex relative to the tubular body whereby the surgical instrument (180) inserted in the tubular body can be manipulated over a wide range of motion inside the thoracic cavity. A retainer ring (160) can be installed at the end of the tubular body opposite to the flange (148) to secure the surgical port in the body wall. Improved obturators (54,100) are provided for installation of the flexible surgical port.

Description: FIELD OF THE INVENTION The present invention generally relates to a trocar assembly for inserting a flexible trocar tube into an opening at an intercostal location in a body wall. BACKGROUND OF THE INVENTION In the past, endoscopic surgery has been facilitated by the use of trocars as operative surgical ports to gain entrance into the body for insertion and manipulation of surgical instruments. Typically, these trocars or ports have employed a thin, rigid cannula as the passageway for various endoscopic instruments. Often, internal pressures in the body cavity are generated by an external positive pressure source and pressure is introduced internally into the body cavity through the trocar tube or cannula, which often employs valves or gaskets to maintain the internal pressure. An exception to this procedure is thoracoscopy, where internal pressures do not need to be maintained. Since the maintenance of internal pressures is not required for thoracoscopy, the associated valves and gaskets may be omitted from the trocars used in thoracic procedures. While it is possible for the thoracic surgery to be performed through small incisions, using existing, non-endoscopic instruments, skin sterility is difficult to maintain and damage to the instruments and to the tissue may occur due to abrasion and friction. Thus, it appears that for thoracic surgery, a need exists for using a trocar tube or port to protect the surgical instruments and the body tissue against damage when the instruments are inserted and manipulated inside the body cavity. Also, since the trocar tube or cannula must be inserted between the ribs for thoracic surgery, a concern about pain arises. A large, rigid trocar tube placed snugly within a relatively small intercostal space may have a tendency to exert pressure upon the intercostal nerve. Also, there is a tendency to disrupt the intercostal nerve by leaning on the instruments. The rigid trocar tube may, as well, limit the motion of the instruments being used to perform the surgery. Thus, it is desirable to provide a trocar tube or cannula for use as a surgical port in thoracoscopy which avoids the concentration of forces at the intercostal location and instead spreads out the forces when the instruments are inserted and manipulated in the body cavity. Also, it is desirable to provide a surgical port which allows a wide range of motion and use of curved instruments or instruments with non-round cross sections. US-A-4545374 suggests the use of a cannula for the insertion of surgical instruments, the cannula being constructed of flexible, resiliant material to accomodate minute bends or stresses caused by the surgeon. SUMMARY OF THE INVENTION The present invention recognizes that a soft or malleable trocar tube can be used to avoid pain and to protect the tissue and surgical instruments in performing thoracic surgery. While flexible trocars are known in the prior art, none has been provided with a variable cross section which is conformable to the available intercostal spacing of individual patients. The invention provides a trocar assembly to facilitate the insertion of a flexible trocar tube or cannula into an intercostal space. A trocar assembly according to the present invention comprises a handle and an elongated obturator mounted on the handle, the obturator having a piercing tip at its distal end; and an elongated trocar tube of flexible material, the obturator having an oval-shaped cross section adapted to stretch the flexible trocar tube into an ovoid shape sufficiently narrow in width to fit between the ribs at an intercostal location in the body wall of a patient. Preferably, the obturator has a collar spaced proximally from the distal end of the obturator, and the trocar tube comprises a hollow tubular body and an annular flange projecting radially outward from one end of the tubular body. In this embodiment, the trocar obturator is insertable into the hollow tubular body of the trocar tube with the collar on the obturator engaging the flange on the trocar tube and the distal end of the obturator extending from the hollow tubular body for inserting the trocar tube into an opening at an intercostal location in a body wall. The collar may be slidably mounted on the trocar obturator and adapted to remain in engagement with the flange as the trocar obturator is withdrawn from the trocar tube. The trocar tube or cannula can be installed at an intercostal space in the body wall with its flange external to the thoracic cavity. The end of the trocar tube distal to the flange may be inserted into an opening in the body wall by use of the obturator until the flange is positioned in contact with the external surface of the body wall. Then the obturator is pulled out of the trocar tube while retaining the trocar tube in place within the body wall. After the flange is secured in place on the body wall, surgical instruments may be inserted through the trocar tube and manipulated inside the body cavity to perform the desired surgical procedures. Alternatively, the trocar tube or cannula can be installed at an intercostal space on the body wall with its flange internal to the thoracic cavity. The trocar tube is inserted through the opening in the body wall with the flange positioned at the distal end of the trocar tube inside the body cavity. After the trocar tube is inserted in this fashion, the flange is spread out into contact with the internal surface of the body wall. With the flange contacting the internal surface of the body wall, the trocar tube presents an extremely clean internal profile which allows the maximum visualization and range of motion of the surgical instruments. Additionally, the proximal end of the trocar tube at the external surface of the body wall may be cut longitudinally into a plurality of flaps which are bent downward and secured to the external body surface by staples, sutures or other suitable fasteners. The trocar tube is adjustable to variable thicknesses of the body wall by varying the length of the cuts made at the external end of the trocar tube. Also, the cut sections or flaps of the trocar tube can be tensioned as desired. In a preferred embodiment of the invention, a retainer ring is placed on the external surface of the body wall surrounding the external or proximal portion of the trocar tube. Suitable fastener means is provided for attaching the ring to the cut sections or flaps of the trocar tube which are bent downward into engagement with the ring. The fastener means may be embodied as hook-like protrusions on the ring which are received in partially formed holes or weakened areas provided on the cut sections or flaps of the trocar tube. A plurality of longitudinally spaced partially formed holes or weakened areas can be formed in the trocar tube to provide an adjustable retention feature. In another embodiment, the trocar tube comprises a pair of spaced parallel stay rods with a flexible band connecting the mid-sections of the stay rods together. The stay rods are adapted for insertion through an intercostal opening in the body wall extending into the thoracic cavity with the flexible band located within the opening. Each of the stay rods is adapted to bend outwardly at its proximal and distal ends into engagement with the body wall to protect the body wall from trauma when a surgical instrument is inserted and manipulated in the surgical port. The stay rods may consist of malleable material which can be bent manually after insertion of the surgical port into the intercostal opening. Alternatively, the stay rods may consist of memory alloy which is temperature activated, e.g., by body heat, after insertion of the surgical port into the intercostal opening to bend the stay rods into the desired configuration. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of the preferred embodiments of the invention with reference to the drawings, in which: Figure 1 is a perspective view of a trocar for installing a trocar tube or cannula of a relatively large diameter in accordance with the invention; Figure 2 is a longitudinal section of the trocar tube or cannula of Figure 1; Figure 3 is a distal end view of the trocar tube or cannula with the trocar inserted therein prior to installation; Figures 4-7 illustrate the installation of the trocar tube or cannula of Figure 1; Figure 7A illustrates the insertion of an endoscopic surgical instrument into the trocar tube or cannula of Figure 1; Figure 7B illustrates the flexing of the trocar tube or cannula of Figure 1 when the instrument is manipulated from side to side; Figures 8-10 show another embodiment of the trocar tube or cannula having its outer ends divided into a plurality of flaps to be fastened to the body wall; Figures 11-13 show another embodiment of the trocar tube or cannula having its outer end divided into a plurality of flaps for attachment to a retainer ring; Figures 14-22 illustrate the procedure for installing the trocar tube or cannula of Figures 11-13 in a body wall; Figure 23 shows the insertion of an endoscopic surgical tool into the trocar tube or cannula; Figures 24 and 25 show the flexing of the trocar tube or cannula when the surgical tool is manipulated from side to side; Figure 26 is an interior perspective view of the trocar tube or cannula with the surgical tool inserted therein; Figure 27 is a perspective view of another embodiment of the trocar tube or cannula including longitudinal reinforcing ribs; Figure 28 is a perspective view of another embodiment of the trocar tube or cannula including criss-crossed reinforcing fibers; DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In Figure 1. a trocar, generally 100, includes a push head or handle 102 which supports an elongated, oval-shaped obturator 104 having a tapered, pointed tip 106. The trocar 100 includes a slidable flange or collar 108 having an oval-shaped slot 110 extending therethrough for slidably receiving the oval-shaped obturator 104. The slidable flange or collar 108 has rounded edges 112 at the top and bottom and flat edges 114 at its opposite sides. The oval-shaped obturator 100 is provided for installing a trocar tube or cannula 120 including a tubular body 122 with a relatively large diameter, e.g., 20 mm., compared with the intercostal spacing of the adjacent ribs in the body wall. The tubular body 122 has an open distal end 124 and an open proximal end 126 provided with an annular flange 128 projecting outward radially from the tubular body 122. Four holes 130 are circumferentially spaced about the flange 128 at equal angular intervals for receiving staples, sutures or other suitable fasteners to secure the flange 128 to the external surface of the body wall. Referring to Figures 4-7, the procedure is shown for installing the trocar tube or cannula 120 in the body wall 80 at an intercostal location between the adjacent ribs 82. The trocar 100 with the trocar flange 108 slidably mounted on the obturator 104 is inserted into the trocar tube or cannula 120 with the trocar flange 108 engaging the handle 102 and the annular flange 128 of the trocar tube 120. The obturator 104 extends through the tubular body 122 with the pointed end 106 extending beyond the distal end 124 of the tubular body 122. As shown in Figure 3, the tubular body 122 of the trocar tube or cannula 120 is flexed into a ovoid shape by the obturator 104. A slit or opening 84 (Figure 4) is cut into the body wall 80 at the desired intercostal location. The trocar 100 is manually moved to align the pointed end 106 of the obturator 104 with the intercostal opening 84. Then the trocar 100 is pushed downward to insert the obturator 104 and the trocar tube or cannula 120 into the body wall 80. The trocar flange 108 engages the annular flange 128 on the trocar tube or cannula 120 and advances the tubular body 122 into the body wall 80 as the trocar 100 is pushed downward. The trocar tube or cannula 120 is pushed downward by the trocar 100 until the annular flange 128 engages the external surface of the body wall 80 (Figure 5). Then the trocar handle 102 is pulled upwardly to remove the obturator 104 from the trocar tube or cannula 120 which is held in place by pressing downward on the trocar flange 108 to hold the annular flange 128 of the trocar tube 120 against the external surface of the body wall 80 (Figure 6). As the oval-shaped obturator 104 is withdrawn, the distal end 124 and proximal end 126 of the tubular body 122 tend to return to the natural circular cross section. Thereafter, if desired, the annular flange 128 is secured to the external surface of the body wall 80 by a set of surgical staples 132 (Figure 7) extending through the holes 130 in the flange 128. Alternatively, the flange 128 can be secured to the body wall 80 by sutures, adhesives or other suitable fasteners. As shown in Figures 7A and 7B, the trocar tube or cannula 120 provides a flexible surgical port which enables surgical instruments to be inserted and manipulated within the thoracic cavity. The annular flange 128 is sufficiently flexible to allow the tubular body 122 to be flexed from side to side to provide a relatively wide range of angular displacement. For example, when the trocar tube 120 is flexed from side to side transversely relative to the ribs 82, a total angular range of approximately 90 to 110 degrees is available for manipulation of the surgical instruments inside the body cavity. Also, when the trocar tube or cannula 120 is flexed from side to side longitudinally between the adjacent ribs 82, a total angular range of approximately 120 to 150 degrees is available for manipulation of the surgical instruments inside the body cavity. Referring to Figures 8-10, a trocar tube or cannula 140 includes a tubular body 142 having an open proximal end 144 and an open distal end 146 provided with an annular flange 148 projecting radially outward from the tubular body 142. The trocar tube or cannula 140 is installed as a surgical port with the annular flange 148 located inside the thoracic cavity in engagement with the internal surface of the body wall 80. The tubular body 142 is longitudinally scored at its outer or proximal end 144 to provide a plurality of thinned strips or score lines 150 which facilitate the separation of the proximal end 144 into a plurality of flaps 152 capable of bending downward into engagement with the external surface of the body wall 80. The trocar tube or cannula 140 is adjustable to variable thicknesses of the body wall 80 by the length of the cuts made along the score lines 150 at the outer-or proximal end 144 of the tubular body 142. Each flap 152 is provided with a a partially formed hole 154 comprising a thinned or weakened area, if desired, for receiving a surgical staple 156 to secure the flap 152 to the body wall 80. Alternatively, sutures, adhesives, or other suitable fasteners can be used to secure the flaps 152 to the body wall 80. Referring to Figures 11-13, in a preferred form of the trocar tube or cannula 140, a flat, annular retainer ring 160 is provided with a central opening 162 which allows the ring 160 to be slipped over the outer or proximal end 144 of the tubular body 142 into engagement with the external surface of the body wall 80. The ring 160 is provided with a plurality of attachment devices, e.g., a series of circumferentially spaced hook-like protrusions 164, for attaching the flaps 152 of the tubular body 142 to the ring 160. The hook-like protrusions 164 are uniformly spaced apart about the circumference of the ring 160 for alignment with the partially formed holes 154 when the flaps 152 are bent downward toward the ring 160. Each flap 152 has one or more partially formed holes or weakened areas 154 arranged in a longitudinal row to permit adjustment of the trocar tube or cannula 140 to accommodate various thicknesses of the body wall 80. The rows of partially formed holes or weakened areas 154 also permit the tension in the flaps 152 to be adjusted. When the flaps 152 are bent downward into engagement with the retainer ring 160, each hook-like protrusion 164 is punched into one of the partially formed holes or weakened areas 154 to secure the flaps 152 to the retainer ring 160. Alternatively, other attachment devices, such as Velcro™, can be used to secure the flaps 152 to the ring 160. Preferably, the partially formed holes or weakened areas 154 are recessed indentations or thinned areas which are not punched through until the flaps 152 are pressed into engagement with the retainer ring 160. In the preferred form, the trocar tube or cannula 140 consists of elastomeric material, e.g., polyeurathane, which is flexible and resilient. The ring 160 can be comprised of a stiff rigid material, a soft flexible material, or a combination of both materials in which the soft flexible material is used for an inner portion of the ring 160 adjacent to the tubular body 142 and the stiff rigid material is used for an outer portion of the ring 160. This construction of the ring 160 may be achieved by co-molding techniques. Referring to Figures 14 and 15 the trocar tube or cannula 140 is installed by using a trocar, generally 170, comprising a handle 172 which supports an elongated obturator 174 provided with a pointed distal tip 176 and an annular flange 162 adjacent to the handle 172. The obturator 174 is oval in cross section to allow the trocar tube 140 to be received in the intercostal spacing of the adjacent ribs 82 in the body wall 80. The obturator 174 is inserted into the unflanged end of the trocar tube or cannula 140 so that the flange 148 is located adjacent to the pointed distal end 176 of the obturator 174. An incision 84 is made at intercostal location in the body wall 80 where it is desired to insert the trocar tube or cannula 140. The trocar 170 is manually moved into proximity with the incision 84 and the pointed distal end 176 of the obturator 174 is aligned with the incision 84. As shown in Figures 16 and 17, the trocar 170 is pushed into the incision 84 to insert the obturator 174 and the trocar tube or cannula 140 into the body wall. As the trocar 170 is advanced, the flange 148 is flexed upwardly by the body wall 80 to allow the tubular body 142 to pass through the body wall 80 between the adjacent ribs 82. As shown in Figures 18 and 19, when the trocar tube or cannula 140 is fully inserted into the body wall 80, the flexible flange 148 returns to its natural position projecting radially outward from the tubular body 142 and the flange 148 engages the internal surface of the body wall 80. Referring to Figures 20 and 21, after the trocar tube or cannula 140 is fully inserted into the body wall 80, the trocar 170 is removed. The ring 160 is slipped over the outer or proximal end 144 of the tubular body 142 and the ring 160 is secured by staples 166 to the external surface of the body wall 80. The longitudinal score lines 150 are cut down to the vicinity of the ring 160 to divide the outer or proximal end 144 of the tubular body 142 into the flaps 152. Referring to Figures 22 and 23, the flaps 152 are bent radially outward and downward into contact with the ring 160: The hook-like protrusions 164 on the ring 160 are punched through the partially formed holes or weakened areas 154 in the flaps 152 to secure the flaps 152 to the ring 160. Each flap 152 is stretched to the desired tension and pressed against the ring 152 to punch the hook-like protrusion 164 through the corresponding partially formed hole or weakened area 154 to secure the trocar tube or cannula 140 in the opening in the body wall 80. The annular flange 148 is firmly held against the internal surface of the body wall 80. The trocar tube or cannula 140 and the retainer ring 160 provide a surgical port in the body wall 80 through which endoscopic surgical instruments, e.g., a grasping forceps 180, can be inserted and manipulated inside the thoracic cavity. Referring to Figures 24 and 25, the flexibility of the trocar tube or cannula 140 allows a relatively severe angle of entry for the endoscopic instruments into the thoracic cavity. For example, the grasping forceps 180 can be inserted through the surgical port at a severe angle between the adjacent ribs 82 to allow the forceps to manipulate a collapsed lung 90. As shown in Figure 25, the tubular body 142, the annular flange 148 and the flaps 152 are all capable of being flexed to permit the forceps 180 to be manipulated at different angles within the thoracic cavity. Also, the retainer ring 160 can be partially or completely made of flexible material to allow the forceps 180 to be moved from side to side at different angles with minimal interference from the surgical port. The flexibility of the trocar tube or cannula 140 permits severe angles of entry for the endoscopic instruments while maintaining an external surface flush with the body wall to avoid clutter in the exterior work space. Also, the flexible material of the trocar tube or cannula 140 acts as a cushion to protect the intercostal nerves and vessels, particularly at severe angles of entry by the endoscopic instruments. As shown in Figure 26, the annular flange 148 is held against the internal surface of the body wall and presents a clean, smooth internal profile to allow maximum visualization and motion of the surgical instruments. Because the annular flange 148 and the retainer ring 160 are firmly held against the internal and external surfaces of the body wall 80, the surgical port provides enhanced tissue protection over the open incision in the body wall 80. In Figure 27, a trocar tube or cannula 190 including a tubular body 192 and an annular flange 194 of flexible material is provided with a plurality of longitudinal reinforcing ribs 196 on the tubular body 192. The reinforcing ribs 196 enhance the axial stiffness of the tubular body 192 and permit bending of the tubular body 192 when endoscopic instruments are inserted into the trocar tube or cannula 190 and manipulated inside the body cavity. Alternatively, as shown in Figure 28, the tubular body 192 may be provided with a plurality of criss-crossed reinforcing fibers 198 which enhance the axial stiffness and permit bending of the trocar tube or cannula 190. The invention in its broader aspects is not limited to the specific details of the preferred embodiments shown and described, and those skilled in the art will recognize that the invention can be practiced with modification within the scope of the appended claims.

Claims: A trocar assembly for inserting a flexible trocar tube (120), into an opening at an intercostal location in a body wall, comprising: a handle (102); and an elongated obturator (104) mounted on said handle and having a piercing tip (106) at its distal end; and an elongated trocar tube (120) of flexible material said obturator having an oval-shaped cross section adapted to stretch the flexible trocar tube (120) into an ovoid shape sufficiently narrow in width to fit between the ribs at the intercostal location in the body wall. A trocar assembly according to claim 1 wherein said elongated trocar tube comprises a hollow tubular body (122) and an annular flange (128) projecting radially outward from one end of said tubular body, and said elongated obturator (104) has a collar (108) spaced proximally from the distal end (106) of said obturator, said trocar obturator (104) being insertable into said hollow tubular body (122) of said trocar tube with said collar (108) engaging said flange (128) and said distal end (106) extending from said hollow tubular body. A trocar assembly according to claim 2 wherein said collar (108) is slidably mounted on said obturator (104). A trocar assembly according to any preceding claim wherein the flexible trocar tube (120) is formed of elastomeric material.

Inventors: GALLAGHER LAURA, HILDWEIN ROGER L, NAGAO REX, RIESTENBERG PAUL, STALEY J D JR, USCHOLD ROBERT C, GALLAGHER, LAURA, HILDWEIN, ROGER L., NAGAO, REX, RIESTENBERG, PAUL, STALEY, J.D., JR., USCHOLD, ROBERT C.
Applicants: ETHICON INC, ETHICON INC.
Application year: 1993
Main classification: A61B17
IPC codes: A61F2, A61B17, A61B1