Device for removing abnormal tissue from the human gastrointestinal tract

Abstract: A method of removing abnormal tissue from the gastrointestinal tract of a patient, comprises the steps of introducing an endoscope (10) into the patient's gastrointestinal tract and applying suction to such abnormal tissue to pull the abnormal tissue into a ligator at the distal end of said endoscope (10). A ligation band (20) is then applied to the base of the abnormal tissue within the ligator to form a polyp. An electro-surgical snare is then used to sever the polyp from the surrounding tissue.

Description: FIELD OF THE INVENTION This invention relates to a device for the removal of portions of the mucosa or submucosa from the digestive tract of a human being. BACKGROUND OF THE INVENTION Diagnostic and therapeutic gastrointestinal endoscopy is commonly used to gain access to the digestive tract for the purpose of observing and removing tissue. Common endoscopic therapeutic instruments include cutting, ablating und unclogging through various know mechanisms. Techniques for obtaining tissues for biopsies include the use of forceps (with or without coagulation), snares or, for cytologic examination, needles and brushes. While these techniques permit the accomplishment of many diagnostic and/or therapeutic goals, in some instances they are inadequate. For example, there currently exists no satisfactory device for the removal of flat malignant mucosal lesions or lesions in the submucosa. On some occasions, deep specimens are required for a diagnosis (e.g. lymphoma or Menetrier's disease) in which cases current procedures are limited. Techniques such as "lift and cut" resection and polypectomy after a submucosal injection of a saline or glucose solution have been used but these procedures are not always successful because on some occasions the tissue does not elevate and in others the injection may actually flatten the area making tissue removal more difficult. These procedures, known as endoscopics mucosectomy are becoming increasingly popular, particulary in Japan where early gastric cancer is common. Elastic band ligation is a process used to control bleeding in portions of the gastrointestinal tract. For example, in the treatment of hemorrhoids or esophageal varices, mucosal and submucosal tissue may be entrapped by an elastic ligature causing strangulation, sloughing off and eventual fibrosis of the lesion. Steigmann U.S. patent No. 4,735,194 illustrates a single band ligating instrument which has achieved commercial success as the Steigmann-Goff Clearvue™ single band ligator. Ligating instruments such as the Steigmann-Goff Clearvue™ ligator are useful in the treatment of esophageal varices and hemorrhoids in which veins that are bleeding of may tent to bleed are isolated by ligation bands; however, ligation has not previously been used for the purpose of treating cancerous and precancerous conditions that may exist in the gastrointestinal tract, in which the abnormal tissue tends to lie flat and is not readily subject to conventional ligation procedures. U.S. Patent No, 4,493,320 relates to a bipolar electrocautery snare for use with endoscopic surgical instruments. The snare includes a unitary double lumen member that includes a septum or divider extending along its length which forms an electrically insulating barrier between the two snare wires. U.S. Patent No. 5,336,222 discloses an integrated catheter assembly that enables a physician to select among hemostatic and injection therapies. U.S. Patent No. 5,014,709 discloses a method and apparatus for high resolution holographic recordation and microscopic examination of an holographic image of biological tissue. Early esophageal cancer is an important problem in many parts of the world. With appropriate screening tests, the diagnosis can be made when the disease is limited to the mucosa or even in a premalignant phase. There an known procedures for the destruction or early esophageal cancer (e.g. laser photocoagulation) but there is an existing need for a device which will permit the efficient and complete removal of tissue from patients with early esophageal cancer and in the other conditions described above. It is an object of this invention to provide an improved device for the removal of cancerous and precancerous tissue within the gastrointestinal tract. SUMMARY OF THE INVENTION The device according the invention comprise a suction channel extending along a length of the endoscope for applying suction to the abnormal tissue to pull the abnormal tissue into a ligator at the distal end of the endoscope, further an inner tube axially disposed at a distal end of the endoscope for applying a ligation band to a base of the abnormal tissuee within the ligator to form a polyp consisting of the abnormal tissue, and an electrosurgical snare including an outer sheath and a wire loop forming a loop which lies in a plane at approximately a right angle to the longitudinal axis of the sheath for severing the polyp. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal view in partial section of the endoscopic ligating instrument illustrating certain features in accordance with this invention, Figs 2-8 are schematic representations of a device illustrating certain features in accordance with the preferred embodiment of the invention; and Fig. 9 is a cross-sectional view of the distal end of a snare in accordance with the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT The invention relates to a mucosectomy device which can be applied to any part of the gastrointestinal tract, including the esophagus, the stomach and the small intestine. For purposes of explanation, the invention is described in its preferred embodiment for removal of a mucosal lesion in the esophagus. In practicing the invention, it is contemplated that a conventional ligator and snare may be used although in a preferred embodiment, and as described in detail below, a specially constructed snare is used. Fig. 1 illustrates a flexible endoscope 10 equipped with a ligator of the type which may be used to practice the invention. Endoscope 10 includes a suction channel 11 and fiberoptics illumination channel 12, both exiting at terminal 13 which is connected to an control box (not shown) for supplying suction and illumination. Eyepiece 14 provides means for viewing the ligation procedure either directly or by video camera and subsequent projection onto a video monitor. Trip wire 15, located in biopsy channel 16, is equipped with weighted handle 17, and is fastened to inner tube 18 at notch. Ligating ring 20 is mounted on inner tube 18 at notch 19. Ligating ring 20 is mounted on inner tube 18, which is positioned within outer tube 21. Outer tube 21 is fastened securely to endoscope 10 by means of threaded connection 22. In utilization of the instrument, elastic ring 20 is mounted over the forward end of the tube 18. Trip wire 15 exiting via biopsy channel 16 is attached to notch 19 at the rearward end of tube 18 and the assembly is placed inside tube 21, which had been securely attached to endoscope 10. Tube 18 is seated within tube 21 with ring 20 protruding just beyond the end of the tube 21, as shown in Fig. 1. Trip wire 15 exiting at the rearward end of endoscope 10 is held in tension by weighted handle 17. After placement of an endoscopic overtube in the patient, the instrument is introduced into the alimentary tract. The target lesion is visualized and the instrument is advanced under direct vision until tube 18 surrounds the intended target. Once full 360° contact is made, suction is activated drawing the lesion into tube 18. When the lesion is totally within tube 18, trip wire 15 is pulled, ring 20 slides off and becomes securely fixed around the base of the target lesion. Figures 2-8 show how a mucosectomy may be performed in the esophagus in accordance with the invention. Endoscope 10 is introduced into the esophagus at a position adjacent the area to be resected (Fig. 2). After the endoscope is in position, a spray catheter 30 (Fig. 3) is introduced through suction channel 11 and the area in question 31 stained, for example, with Lugol's iodine which is a conventional stain that will turn brown when it contacts tissue cells containing glycogen. Cancerous and precancerous cells do not contain glycogen and therefore do not accept the stain. In this way the abnormal tissue 31 can be identified endoscopically. After the section in question has been stained, the spray catheter 30 is removed and an injection catheter 32 (Fig. 4) introduced through suction channel 11 of the endoscope. A saline solution (for example, 0,9% NaCl) is injected into the stained area to elevate it from the surrounding tissue of the esophagus (Fig. 5.). Other materials such as glucose solution may be used to elevate the abnormal area. The injection catheter 32 and the endoscope 10 are removed from the patient's esophagus and a single fire ligator secured to the distal end of the endoscope, as shown in Fig. 1. The endoscope is then reintroduced into the patient's esophagus so that the distal end of the ligator is adjacent the elevated abnormal area (Fig. 6). Suction is applied through suction channel 11 to pull the abnormal are into the ligator. The trip wire 15 is then pulled to apply a ligator band 18 around the base of the abnormal area so that when the ligator is removed, a banded mushroom-like polyp 34 is formed (Fig. 7). The endoscope 10 is removed from the patient and the ligator is detached from the endoscope. The endoscope again is inserted into the esophagus. When the banded "polyp" is in view, a conventional snare comprising a wire loop 36 and sheath 38 may be introduced through the biopsy channel 16 of the endoscope. The snare is positioned so that the wire loop envelops the artificially created polyp (Fig. 8). When the wire loop 36 is pulled into the sheath 38 the polyp is cut from the esophagus and cauterised. The polyp may be withdrawn physically by the snare through the endoscope or released into the patient's gastrointestinal tract. The snare used in Fig. 8 may be conventional, for example, a monopolar electrosurgery device which simultaneously cuts and cauterises tissue, such as a polyp or the like. Typically, such snares comprise a wire loop which may be retracted into a sheath causing the loop tighten around the polyp. The application of voltage simultaneously severs the polyp and cauterises the wound. The distal end of a snare especially adapted for use with the invention is shown in Fig. 9. The outer sheath of the snare is shown at 38 and the wire loop at 36. A conductive pull wire 29 is attached to the loop 36 by a connector 37 which may be crimped and soldered to adjacent ends of wire 39 and loops 36. Unlike conventional snares, the free end of the wire 36 is connected to a small ferrule 40 which is attached, for example, by adhesive, to the distal end of the sheath 38. The wire loop 36 may be soldered to the ferrule 40. With this arrangement, the loop 36 may be permanently bent at points so that when the wire 39 is pushed distally (as shown in Fig. 9), the lop which is formed lies in a plane at an angle close to ninety degrees with respect to the longitudinal axis of sheath 38. In contrast to conventional snares in which the loop when extended lies in the same plane as the longitudinal axis of the sheath, the arrangement of Fig. 9 is particularly useful in removing a "polyp" formed by the use of the ligator of Fig. 1 as represented in Fig. 6 and 7. The handle of the snare at its proximal end may be conventional handle of the snare at its proximal end may be conventional and, therefore, is not illustrated. Having thus described a preferred embodiment of the present invention, it is to be understood that the above described is merely illustrative of the principles pf the present invention, and that other devices may be devised by those skilled in the art without departing from the scope of the appended claims. LIST OF REFERENCES: 10 flexible endoscope 11 suction channel 12 illumination channel 13 terminal 14 eyepiece 15 trip wire 16 biopsy channel 17 handle 18 inner tube 19 notch 20 ligating ring 21 outer tube 22 connection 30 spray catheter 31 area in question 32 injection catheter 34 mushroom-like polyp 36 wire loop 37 connector 38 sheath 39 pull wire 40 ferrule

Claims: A device inserted into an endoscope for removing abnormal tissue from the gastrointestinal tract of a patient, comprising: a suction channel (11) extending along a length of the endoscope (10) for applying suction to the abnormal tissue to pull the abnormal tissue into a ligator at the distal end of the endoscope (10), an inner tube (18) axially disposed at a distal end of the endoscope (10) for applying, a ligation band (20) to a base of the abnormal tissue within the ligator to form a polyp (34) consisting of the abnormal tissue, and an electrosurgical snare including an outer sheath (38) and a wire loop (36) forming a loop (36) which lies in a plane at approximately a right angle to the longitudinal axis of the sheath (38) for severing the polyp (34). A device according to claim 1, further comprising: an injection catheter (32) for raising abnormal tissue before pulling of the tissue into the ligator. A device according to claim 1, further comprising: a removable spray catheter (30) axially disposed with the endoscope (10) for applying a stain to the abnormal tissue prior to ligation.

Inventors: LANTAGNE STEVEN, LIEBMANN VERN L, LANTAGNE, STEVEN, LIEBMANN, VERN L.
Applicants: BARD INC C R, C.R. BARD, INC.
Application year: 1996
Main classification: A61B17
IPC codes: A61B18, A61B17, A61B19