Elastic band ligation device with anti-pinch feature and method for treatment of hemorrhoids

Abstract

An elastic band ligation device for treatment of hemorrhoids including an inner tubular member for retaining a stretched elastic band over the front end thereof, a plunger in the tubular member with a handle extending away from the front end of the inner tubular member, the handle for sliding the plunger away from the rear end of the inner tubular member to provide a suction for drawing hemorrhoidal tissue into the inner tubular member through the opening at the front end. An obturator is disposed within the inner tubular member having a rounded end, the end of the obturator and the inner surface of the inner tubular member defining an anti-pinch structure. An outer tubular pusher sleeve is configured to provide a limited friction fit over the inner tubular member, with an external end of the outer tubular pusher sleeve adjacent the stretched elastic band.

What is claimed is: 
     
         1 . An elastic band ligation device for treatment of hemorrhoidal tissue, comprising:
 an inner tubular member having a front end and a rear end, for retaining a stretched elastic band over the front end thereof, the front end having an opening,   a plunger in the inner tubular member with a handle extending away from the front end of the inner tubular member, the handle for sliding the plunger away from the rear end of the inner tubular member to provide a suction for drawing hemorrhoidal tissue into the inner tubular member through the opening at the front end,   an obturator within the inner tubular member having a distal end, the distal end of the obturator and the inner surface of the inner tubular member defining an anti-pinch structure for reducing pinching of tissue between the outer surface of the end of the obturator and the inner surface of the inner tubular member,   an outer tubular pusher sleeve configured to provide a limited friction fit over the inner tubular member, with an external end of the outer tubular pusher sleeve adjacent the stretched elastic band.   
     
     
         2 . The elastic band ligation device according to  claim 1 , wherein the obturator and the plunger are integrally formed. 
     
     
         3 . The elastic band ligation device according to  claim 2 , wherein outer surface of the end of the obturator is convergent towards the distal tip of the obturator and creates an angle of 30 degrees or less between the outer surface of the obturator end and the inner surface of the inner tubular member. 
     
     
         4 . The elastic band ligation device according to  claim 3 , wherein the angle is 5-25 degrees. 
     
     
         5 . The elastic band ligation device according to  claim 1 , wherein the distal end of the obturator has a region of reduced diameter towards the tip to facilitate entry of the device into the rectum of the patient and to reduce the incidence of pinching of tissue as the obturator is withdrawn into the device after deployment of a band onto the hemorrhoidal tissue. 
     
     
         6 . The elastic band ligation device according to  claim 1 , wherein a flexible anti-pinch wiper element material is connected to the end of the inner tubular member and abuts against the outer surface of the end of the obturator to prevent tissue from being trapped or pinched between the outer surface of the end of the obturator and the inner surface of the inner tubular member. 
     
     
         7 . The elastic band ligation device according to  claim 6 , wherein the wiper element is flexible and is made of a thin plastics material. 
     
     
         8 . The elastic band ligation device according to  claim 1 , wherein the end of the obturator has parallel walls rounded at the tip of the obturator, to reduce pinching of tissue. 
     
     
         9 . The elastic band ligation device according to  claim 1 , further comprising a locking mechanism provided at an opposite end of the outer tubular pusher sleeve for locking the outer pusher sleeve and the inner tubular member to prevent relative movement therebetween, said locking mechanism being provided with a tab which when pressed in use disengages the outer pusher sleeve from the inner tubular member and allows the outer pusher sleeve to be moved towards the front end of the inner tubular member and into contact with the elastic band to urge the elastic band away from the front end of the inner tubular member and into engagement with hemorrhoidal tissue extending through the opening in the inner tubular member. 
     
     
         10 . The elastic band ligation device according to  claim 9 , wherein the tab is provided with a lug extending transversely from the tab towards the inner tubular member. 
     
     
         11 . The elastic band ligation device according to  claim 9  wherein the inner tubular member is provided with a locking ring against which the tab abuts to prevent relative movement of the inner tubular member and the outer pusher sleeve. 
     
     
         12 . The elastic band ligation device according to  claim 11 , wherein the locking ring has an abutment surface. 
     
     
         13 . The elastic band ligation device according to  claim 12 , wherein the lug engages the abutment surface to prevent relative movement of the inner tubular member and the outer pusher sleeve. 
     
     
         14 . The elastic band ligation device according to  claim 13 , wherein upon pushing the tab away from the inner tubular member, the lug moves out of abutting relationship with the abutment surface which allows the outer pusher sleeve to be moved relative to the inner tubular member towards the front end of the device, thereby to push an elastic band off the front end of the device onto hemorrhoidal tissue. 
     
     
         15 . The elastic ligation device according to  claim 9 , wherein the outer pusher sleeve includes cut-outs adjacent the tab for permitting adjustment to tune the force required to deflect the tab away from the inner tubular member. 
     
     
         16 . The elastic ligation device according to  claim 1 , wherein a circumferential ring marker is provided on the external circumference of the outer tubular pusher sleeve as a depth marker to the user with regard to the extent of insertion of the device into the rectum of the patient. 
     
     
         17 . The elastic ligation device according to  claim 1 , further comprising an elastic band introducer for facilitating introduction of bands onto the inner tubular member. 
     
     
         18 . The elastic ligation device according to  claim 17 , wherein the introducer has a tapered region and a flat region. 
     
     
         19 . The elastic ligation device according to  claim 18 , wherein the introducer has surface ribs and channels extending along the tapered region. 
     
     
         20 . The elastic band ligation device according to  claim 17 , wherein the introducer has a slot in the flat region which receives the distal end of the inner tubular member  4 .