BACKGROUND OF THE INVENTION

Field of the Invention

The present patent application is generally related to treating wounds, and is more specifically related to trocars used to advance wound drain catheters through tissue for safely and efficaciously draining fluids from wounds.

Description of the Related Art

Trocars are often used to insert wound drain catheters into a drainage site adjacent a surgical wound. Typically, a trocar has a wound drain catheter attached to an end of the trocar so that the tubing of the wound drain catheter follows the trocar along a path through the patient's body.

Several techniques may be used to insert a wound drain catheter in a patient's body. For example, a surgeon may simply place a drain and a small section of the wound drain catheter in the wound, close the incision, and suture around the wound drain catheter. This technique is somewhat unsatisfactory, since it is difficult to completely seal the area around the wound drain catheter by suturing, and thus, the wound may become infected. A more satisfactory technique is to pass a trocar, pre-attached to an end of the wound drain catheter, through healthy tissue by entering the patient's body at a point within the wound and exiting the body at an opening formed in skin. The surgeon uses the trocar to pull the wound drain catheter through the tissue until the wound drain catheter is properly positioned, with the drain located in the wound. Since the wound drain catheter exits the body at a point adjacent the wound, the wound can be completely closed by suturing, thereby reducing the risk of infection.

In some instances, when positioning a wound drain catheter at a wound site, the trocar and the wound drain catheter separate, leaving the end of the wound drain catheter in the patient's body. If this occurs, the wound drain catheter must be removed and the procedure repeated. Such separation is typically due to the difficulty of attaching the trocar to the wound drain catheter.

In some instances, trocars are manufactured with a slight bend near the sharpened tip of the trocar to allow the trocar to be manipulated through the tissue and/or skin of the patient. The wound drain catheter will follow the path made by the trocar until the drainage end of the wound drain catheter is located at a desired position within the body and the extension portion of the wound drain catheter is located outside the patient's body. At that stage, the trocar is separated from the wound drain catheter, whereupon the free end of the wound drain catheter is connected to a source of vacuum.

U.S. Pat. No. 4,398,910 discloses the use of a trocar in the manner described above. U.S. Pat. No. 4,359,053 discloses the fastening of plastic tubing to a trocar for the same purpose.

Trocars are typically made of very hard surgical grade stainless steel or other materials so that they may be sharpened to a very fine point to allow the sharpened tip of the trocar to pass through body tissue and skin. In many instances, it is difficult to properly position the wound drainage tubing because it is difficult to pass the trocar through the patient's body without hitting a solid structure such as bone. It is also desirable to avoid organs and sensitive tissue as the trocar advances through a patient.

U.S. Pat. No. 3,398,910 discloses a trocar that is manufactured to have a slight bend of about 15 degrees to allow the trocar to be manipulated through the body of the patient to correctly position the wound drain catheter at a location desired by the surgeon.

U.S. Pat. No. 4,976,684 to Broadnax, Jr. discloses a trocar that is used to insert wound drainage tubing into the body of a patient. The trocar has a sharpened tip and a shaft that is capable of being bent by a surgeon to a configuration that is desired by the surgeon, which allows easier and more accurate insertion of the wound drain catheter in the desired location in the patient's body. The trocar has an area of reduced cross section, located near the sharpened tip, which allows the trocar to be bent with a force that is generated by the hands of the surgeon.

The use of a trocar having a sharpened tip to introduce wound drain catheters in patients requires great care to assure that the sharpened tip of the trocar does not injure sensitive tissues of the patient (e.g., vessels and nerves).

Thus, there remains a need for trocars that may be used to introduce wound drain catheters in patients in a way that reduces the risk of unwanted tissue damage. There also remains a need for trocars that are readily bendable for passing through patients without injuring sensitive tissue and organs. In addition, there remains a need for trocars having blunt tips that minimize the possibility of tissue damage. Moreover, there remains a need for trocars that have a reduced diameter midsection that is located about midway between the leading end and the trailing end of the elongated shaft of the trocar. Further still, there remains a need for trocars that maintain reliable connections with wound drain catheters so that the trocars and wound drain catheters remain secured together during deployment.

SUMMARY OF THE INVENTION

In one embodiment, a trocar preferably includes an elongated shaft having a leading section, a trailing section, a reduced diameter midsection located between the leading and trailing sections, and a longitudinal axis extending from a leading end of the leading section to a trailing end of the trailing section of the elongated shaft. The trocars may have French sizes of about Fr 10-Fr 24.

In one embodiment, the leading section of the elongated shaft has a tapered region that terminates at a blunt tip located at the leading end of the elongated shaft. In one embodiment, a trocar having a blunt tip may help reduce a risk of unwanted puncturing of tissue and may also improve safety during use by a doctor, nurse, or other user.

In one embodiment, the trailing section of the elongated shaft has a connector located at the trailing end of the elongated shaft.

In one embodiment, the leading and trailing sections of the elongated shaft have a first diameter and the reduced diameter midsection of the elongated shaft has a second diameter that is smaller than the first diameter for enabling the elongated shaft to be bent at the reduced diameter midsection.

In one embodiment, the elongated shaft is made of various materials including but not limited to metals, biocompatible metals, medical grade steel, stainless steel, 303 stainless steel, and polymers.

In one embodiment, the leading and trailing sections of the elongated shaft are relatively more rigid than the reduced diameter midsection of the elongated shaft. In one embodiment, the reduced diameter midsection is more flexible, bendable and/or malleable than the leading and trailing sections of the elongated shaft.

In one embodiment, the elongated shaft includes an outer surface having a cylindrical shape. The elongated shaft may have cross-section having a circular shape.

In one embodiment, the tapered region includes a sloping surface that tapers away from the longitudinal axis of the elongated shaft.

In one embodiment, the blunt tip includes a flat surface having an outer perimeter. In one embodiment, the blunt tip has a convexly curved surface surrounding the outer perimeter of the flat surface and extending from the outer perimeter of the flat surface to the sloping surface of the tapered region.

In one embodiment, the sloping surface of the tapered region and the longitudinal axis of the elongated shaft cooperatively define an angle of about 3-5 degrees. In one embodiment, the flat surface of the blunt tip has an outer diameter of about 0.030-0.045 inches.

In one embodiment, the first diameter of the leading and trailing sections of the elongated shaft is about 0.125-0.250 inches, and the second diameter of the reduced diameter midsection is about 0.0875-0.0975 inches.

In one embodiment, the elongated shaft has a length of about 6 inches. In one embodiment, the leading section of the elongated shaft has a length of about 2.75 inches. In one embodiment, the tapered region of the leading section has a length of about 0.741 inches. In one embodiment, the reduced diameter midsection has a length of about 0.400-0.500 inches.

In one embodiment, the reduced diameter midsection is located midway between the leading and trailing ends of the elongated shaft.

In one embodiment, the connector includes an end knob having a curved surface, and one or more annular ridges located between the end knob and an end face at the trailing end of the trailing section of the elongated shaft.

In one embodiment, the end knob has an end knob outer diameter and the annular ridges have respective annular ridge outer diameters that are larger than the end knob outer diameter.

In one embodiment, a wound drain catheter may be secured to a trailing end of the trocar. In one embodiment, the wound drain catheter is a flexible tube made of a biocompatible material such as silicone. In one embodiment, the wound drain catheter has a first end and a second end. In one embodiment, the first end of the wound drain catheter is secured to the connector. In one embodiment, the wound drain catheter has an outer diameter that matches the first diameter of the leading and trailing sections of the elongated shaft. In one embodiment, a drain is secured to the second end of the flexible wound drain catheter.

In one embodiment, a trocar system preferably includes a shaft having a leading section, a trailing section, a reduced diameter midsection located between the leading and trailing sections, and a longitudinal axis extending from a leading end of the leading section to a trailing end of the trailing section of the elongated shaft. In one embodiment, the leading section of the shaft has a tapered region that terminates at a blunt tip located at the leading end thereof, and the trailing section of the shaft has a connector located at the trailing end thereof.

In one embodiment, the leading and trailing sections of the shaft have a first diameter and the reduced diameter midsection of the shaft has a second diameter that is smaller than the first diameter for enabling the shaft to be bent at the reduced diameter midsection.

In one embodiment, a first end of a flexible wound drain catheter is secured to the connector at the trailing end of the trailing section of the shaft. In one embodiment, the flexible wound drain catheter has an outer diameter that matches the first diameter of the leading and trailing sections of the shaft.

In one embodiment, the tapered region of the leading section of the elongated shaft preferably includes a sloping surface that tapers away from the longitudinal axis of the elongated shaft.

In one embodiment, the blunt tip desirably includes a flat surface. In one embodiment, the flat surface is orthogonal to the longitudinal axis of the elongated shaft of the trocar. In one embodiment, the flat surface of the blunt tip has an outer perimeter and a convexly curved surface surrounding the outer perimeter of the flat surface and extending from the outer perimeter of the flat surface to the sloping surface of the tapered region.

In one embodiment, a method for draining fluid from a mammal preferably includes attaching a flexible wound drainage catheter to a trocar. In one embodiment, the trocar may have an elongated shaft including a leading section, a trailing section, a reduced diameter midsection located between the leading and trailing sections, and a longitudinal axis extending from a leading end of the leading section to a trailing end of the trailing section of the elongated shaft.

In one embodiment, the leading section of the elongated shaft preferably has a tapered region that terminates at a blunt tip located at the leading end thereof. In one embodiment, the trailing section of the elongated shaft preferably has a connector located at the trailing end thereof.

In one embodiment, the leading and trailing sections of the elongated shaft desirably have a first diameter and the reduced diameter midsection of the elongated shaft has a second diameter that is smaller than the first diameter for enabling the elongated shaft to be bent at the reduced diameter midsection

In one embodiment, the method preferably includes bending the trocar to an angulated configuration, and after the bending the trocar, passing the trocar through skin of a mammal, whereby the trocar maintains the angulated configuration while passing through the skin of the mammal.

In one embodiment, the method preferably includes passing the trocar out of the skin of the mammal, while maintaining the flexible wound drain catheter within the mammal.

In one embodiment, the method includes draining fluid from the mammal through the flexible wound drain catheter, such as by coupling a source of vacuum to an end of the wound drain catheter that extends outside the body of the patient.

In one embodiment, a method of implanting wound drain catheter may include bluntly dissecting tissue starting from the inside of a body cavity to create a partial pathway toward the skin layer, introducing the blunt point of a trocar carrying a wound drain catheter into the partial pathway, using a sharp instrument to create a small incision in the skin at the location where the blunt point of the trocar will emerge, advancing the trocar through the incision, and detaching the wound drain catheter from the trocar.

In one embodiment, the tapered region of the leading section of the elongated shaft includes a sloping surface that tapers away from the longitudinal axis of the elongated shaft. In one embodiment, the blunt tip preferably includes a flat surface having an outer perimeter and a convexly curved surface surrounding the outer perimeter of the flat surface and extending from the outer perimeter of the flat surface to the sloping surface of the tapered region.

In one embodiment, the first diameter of the leading and trailing sections of the elongated shaft is about 0.125-0.250 inches, and the second diameter of the reduced diameter midsection is about 0.0875-0.0975 inches.

In one embodiment, the elongated shaft of the trocar preferably has a length of about 6 inches, the leading section of the elongated shaft has a length of about 2.75 inches, the tapered region of the leading section has a length of about 0.741 inches, and the reduced diameter midsection has a length of about 0.400-0.500 inches.

These and other preferred embodiments of the present patent application will be described in more detail herein.

