Abstract:
A medical device, such as a nasal-jejunal feeding tube, having an arrangement of flaps cut from the outer surface of the catheter and configured so as to not readily adhere to the catheter outer surface. The arrangement of flaps are configured to resist egress so as to permit peristaltic contractions of the body to propel the device forward, yet will allow the device to be removed from the body without the flaps causing significant trauma to the tissues of the body canal.

Description:
RELATED APPLICATIONS 
     This application is continuation-in-part of U.S. application Ser. No. 09/184,331, filed Nov. 2, 1998 now U.S. Pat. No. 6,589,213, which is a continuation-in-part of U.S. application Ser. No. 08/989,413, filed Dec. 12, 1997 (now abandoned), both entitled “Body Canal Intrusion Instrumentation Having Bidirectional Coefficient of Surface Friction with Body Tissue”. 
     This application also claims the benefit of U.S. Provisional Application No. 60/292,146, filed May 18, 2001, entitled “Body Canal Intrusion Instrumentation Having Bidirectional Coefficient of Surface Friction with Body Tissue”. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates to instrumentation for invading body canals non-destructively and with a minimum of trauma, and more particularly, to the interface between the instruments and body tissue during dynamic ingress and egress of surgical instrumentation into the canals. 
     BACKGROUND OF THE INVENTION 
     It has been the direction of the prior art to fashion the surface structure of instrumentation used for the non-destructive invasion of body canals with a very slippery surface to facilitate ingress of the instrumentation into the body canal. The resulting slippery surface also produces low friction during egress of the instrumentation from the body canal. 
     As set forth in detail in U.S. application Ser. No. 09/184,331, filed Nov. 2, 1998, entitled “Body Canal Intrusion Instrumentation Having Bidirectional Coefficient of Surface Friction with Body Tissue”, and which is hereby incorporated by reference, it has been found that the ingress of the medical device or other instrumentation into a desired body site can be facilitated by the utilization of a surface structure on the device having a bi-directional coefficient of friction with respect to the tissue within the body cavity or canal that is engaged by the device during ingress. For example, it has been found that naturally occurring peristaltic contractions tend to grasp and carry the device toward the desired work site. This significantly decreases the risk of puncture by the device, as well as reduces the time required by the surgeon for entry and positioning of the device at the desired work site. These advantages are particularly important during procedures such as the insertion of a gastric or jejungal feeding tube through the esophagus and into or through the stomach or small intestine. 
     Large flaps or barbs have been used on the outside surface of catheters and related devices for the purpose of stabilizing or anchoring the device within the body canal. These flaps or barbs are designed to prevent both ingress and egress of the device once the device has been positioned at the desired location within the body canal. These flaps or barbs are typically rigid, and are attached to the outside of the device in a hinged manner. However, these devices can be very traumatic to the tissue of the body canal, and can be very uncomfortable to the patient, when manipulated within the body or upon egress from the body canal. 
     In view of the above, there is a need for a medical device or other instrumentation having a series of flaps that function in a bi-directional manner to engage the tissue of the body canal so as to assist with ingress of the device, but which will permit egress of the device without causing trauma or discomfort to the patient. 
     BRIEF SUMMARY OF THE INVENTION 
     The foregoing problems are solved and a technical advance is achieved in a medical device, such as a gastrointestinal catheter, for use in delivering fluid-like materials to the gastrointestinal tract. Such fluid-like materials could include feeding materials, drugs, contrast materials or saline. 
     The illustrative embodiment of the present invention is directed to a nasal-jejunal feeding tube having an arrangement of flaps cut from the outer surface of the catheter and configured so as to not readily adhere to the catheter outer surface. The arrangement of flaps are also configured so as to resist egress to the degree that allows the body to propel the device forward, yet will allow the device to be removed from the body without the flaps causing significant trauma, such as inflammation, to the tissues of the body canal, and thereby minimizing or eliminating patient discomfort. 
     The preferred embodiment illustrated herein comprises a 14 FR nasal-jejunal feeding tube having a minimum overall length of 154 cm. A series of flaps are formed on the outer surface of the distal 50 cm of the catheter portion. Four longer flaps are formed near the distal end of the feeding tube, and are arranged about the perimeter of the feeding tube at approximately equal intervals (i.e., at 90° intervals with respect to each other). A number of shorter flaps are distributed along the length of the feeding tube inwardly or proximally from the four longer flaps. These shorter flaps alternate along opposite sides of the feeding tube at approximately 2 cm intervals for the distal 50 cm of the catheter. The feeding tube also includes several apertures distributed along the distal portion of the catheter. These feeding tube apertures alternate along opposite sides of the feeding tube at approximately 2 cm intervals, and are generally disposed at 900 intervals with respect to the shorter flaps. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a side view of an illustrative embodiment of a body canal intrusion instrument in accordance with the teachings of this invention. In particular, FIG. 1 is a side view of the distal portion of a nasal-jejunal feeding tube made in accordance with the teachings of this invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is directed to a medical device  100 , such as a gastrointestinal catheter, for use in delivering fluid-like materials to the gastrointestinal tract. Such fluid-like materials could include feeding materials, drugs, contrast materials or saline. In particular, an illustrative embodiment of the present invention is shown in FIG. 1, which depicts the distal portion of a nasal-jejunal feeding tube having a plurality of bidirectional surface elements  102  distributed along the outer surface  104  of the catheter portion  106  of the device  100 . 
     In the illustrative embodiment shown, a group of four (4) distal flaps  108  are disposed about the perimeter of the catheter outer surface  104  at approximately equal intervals (i.e., at 90° intervals). The distal flaps  108  are positioned near the distal tip  110  of the device  100 . In the preferred embodiment, the distal flaps  108  comprise a first oppositely disposed pair of distal flaps  112  located approximately 0.7 cm from the distal tip  110  of the feeding tube  100 , and a second oppositely disposed pair of distal flaps  114  located approximately 1.0 cm from the distal tip  110  of the device  100 , as measured from the base  116  of each of the flaps  112 ,  114 . 
     In the preferred embodiment shown, each of the distal flaps  108  are approximately 1.0 cm in length, when straightened. The distal flaps  108  are preferably formed by cutting a portion of the catheter outer surface  104 . In addition, each of the distal flaps  108  are curved (or curled) so as to prevent the flaps  108  from adhering to the outer surface  104  of the catheter, and so as to orient the tips  120  of the distal flaps  108  forwardly (i.e., towards the distal tip  110  of the device  100 ). Preferably, each of the distal flaps  108  is curved by utilizing a cutting technique that results in the formation of a distal flap  108  that tends to curve outwardly from the outer surface  104  of the catheter. Depending on the type of material from which the catheter is manufactured, curving of the distal flaps  108  may also be accomplished by heat curving. 
     The configuration and orientation of the distal flaps  108  resist egress of the device  100 , and also causes the device to be propelled forwardly by naturally occurring peristaltic contractions of the tissue of the body canal (not shown). In particular, when the device  100  is being inserted into the body canal, the distal flaps  108  provide a relatively large diameter near the distal tip  110  of the device  100  that can be readily grasped by the tissue of the body canal during peristaltic contractions. However, when the device  100  is being removed from the body canal, the forward orientation of the tips  120  prevent trauma to the tissue. In addition, the distal flaps  108  are sufficiently flexible to prevent trauma to the tissue of the body canal upon either ingress or egress of the device  100 . 
     A plurality of secondary flaps  118  are disposed along the outer surface  104  of the catheter inwardly (or proximal) from the distal tip  110  and the distal flaps  108 . In the preferred embodiment shown, the secondary flaps  118  are distributed along the distal  50  cm of the catheter portion  106  of the feeding tube. The secondary flaps  118  alternate along opposite sides of the feeding tube at approximately 2 cm intervals. In other words, the secondary flaps  118  comprise a first series of secondary flaps  126  disposed along the top side of the feeding tube (as viewed in FIG. 1) and spaced at approximately 4 cm intervals, and a second series of secondary flaps  128  disposed along the bottom side of the feeding tube (as viewed in FIG. 1) and spaced there between. 
     Although not shown in the drawing of the illustrative embodiment, it should be appreciated that the secondary flaps  118  can be arranged in numerous other configurations. For example, the secondary flaps  118  can be disposed along the catheter portion  106  of the feeding tube in a spiral or random configuration. The secondary flaps  118  can also be disposed along more than two sides of the catheter portion  106 . It is also not necessary for the secondary flaps  118  to be disposed in an alternating fashion along opposite sides of the catheter portion  106 . 
     In the preferred embodiment, each of the secondary flaps  118  measures approximately 0.5 cm in length, when straightened. Each of the secondary flaps  118  has a truncate shape comprising a base  122  measuring approximately 0.016 cm in width, and a tip  124  measuring approximately 0.010 cm in width. The secondary flaps  118  are preferably formed by cutting a portion of the catheter outer surface  104 . 
     In addition, each of the secondary flaps  118  are moderately curved outwardly so as to prevent the secondary flaps  118  from adhering to the outer surface  104  of the catheter, and to allow the tip  124  to engage the tissue of the body canal (not shown). Preferably, each of the secondary flaps  118  is curved by utilizing a cutting technique that results in the formation of a secondary flap  118  that tends to curve outwardly from the outer surface  104  of the catheter. Depending on the type of material from which the catheter is manufactured, curving of the secondary flaps  118  may also be accomplished by heat curving. 
     The secondary flaps  118  are also configured so as to orient the tips  124  of the secondary flaps  118  rearwardly (ie., away from the distal tip  110  of the device  100 ). This rearward orientation of the secondary flaps  118  resist egress of the device  100 , and causes the device to be propelled forwardly by naturally occurring peristaltic contractions of the tissue of the body canal during the insertion process. In addition, the relatively low profile of the secondary flaps  118  minimizes trauma to the tissue during the removal process. The secondary flaps  118  are also sufficiently flexible to prevent trauma to the tissue of the body canal upon either ingress or egress of the device  100 . 
     The feeding tube further comprises feeding tube apertures  130  disposed along the distal portion of the catheter. The feeding tube apertures measure approximately 0.5 cm in diameter, and provide openings through which feeding material can exit the interior of the feeding tube and enter the body canal or cavity. In the embodiment shown, the feeding tube apertures  130  are alternately disposed along opposite sides of the feeding tube at approximately 2 cm intervals, and are preferably located on the sides of the feeding tube that are 90° offset from the sides of the feeding tube along which the secondary flaps  118  are located (i.e., along the front and back sides of the feeding tube as viewed in FIG.  1 ). The illustrative embodiment comprises a total of five (5) feeding tube apertures  130 . 
     The above described arrangement and dimensions provided for elements thereof are merely exemplary. Any other undisclosed or incidental details of the construction or composition of the various elements of the disclosed embodiments of the present invention are not considered to be critical to the achievement of the advantages of the present invention, so long as the elements possess the attributes required to perform as disclosed herein. The selection of these and other details of construction are believed to be well within the ability of one of ordinary skill in the relevant art in view of the present disclosure. Illustrative embodiments of the present invention have been described in detail for the purpose of disclosing practical, operative structures whereby the invention may be practiced advantageously. The designs described herein are intended to be exemplary only. The novel characteristics of the invention may be incorporated in other structural forms without departing from the spirit and scope of the invention.