Endoclip

An endoclip is a metallic mechanical device used in endoscopy in order to close two mucosal surfaces without the need for surgery and suturing. Its function is similar to a suture in gross surgical applications, as it is used to join together two disjointed surfaces, but, can be applied through the channel of an endoscope under direct visualization. Endoclips have found use in treating gastrointestinal bleeding (both in the upper and lower GI tract), in preventing bleeding after therapeutic procedures such as polypectomy, and in closing perforations of the gastrointestinal tract. Many forms of endoclips exist of different shapes and sizes, including two and three prong devices, which can be administered using single use and reloadable systems, and may or may not open and close to facilitate placement.

tructure and function

The endoclip was first described by Hayashi and Kudoh in 1975, cite journal |author=Devereaux CE, Binmoeller KF |title=Endoclip: closing the surgical gap |journal=Gastrointest. Endosc. |volume=50 |issue=3 |pages=440–2 |year=1999 |pmid=10462677 |doi=10.1053/ge.1999.v50.99616] and was termed the "staunch clip". Initial attempts to incorporate the clip into applications in endoscopy (such as clipping bleeding blood vessels) were limited by the applicator system of the clip. However, by 1988, an easy to use applicator delivery system was developed, and a functional reloadable endoclip system was described. cite journal |author=Binmoeller KF, Thonke F, Soehendra N |title=Endoscopic hemoclip treatment for gastrointestinal bleeding |journal=Endoscopy |volume=25 |issue=2 |pages=167–70 |year=1993 |pmid=8491134 |doi=] This consisted of a stainless steel clip (of size approximately 6 mm long and 1.2 mm wide at the prongs) with a metal deployment device (that could be used to insert the clip into the endoscopic camera, and deployed outside the camera) enclosed in a plastic sheath. These clips were initially reloadable.

Endoclips in use today have a variety of additional sizes, shapes and sizes. Clips with two and three prongs (TriClip, Cook Medical cite web |url= http://www.cookmedical.com/esc/dataSheet.do?id=700|title= TriClip Endoscopic Clipping Device|accessdate=2007-05-15 |format= |work= ] ) have been described and used for various applications. cite journal |author=Lin HJ, Lo WC, Cheng YC, Perng CL |title=Endoscopic hemoclip versus triclip placement in patients with high-risk peptic ulcer bleeding |journal=Am. J. Gastroenterol. |volume=102 |issue=3 |pages=539–43 |year=2007 |pmid=17100962 |doi=10.1111/j.1572-0241.2006.00962.x] Rotatable clips have been devised to improve localization of deployment. cite journal |author=Yoshikane H, Hidano H, Sakakibara A, Niwa Y, Goto H |title=Feasibility study on endoscopic suture with the combination of a distal attachment and a rotatable clip for complications of endoscopic resection in the large intestine |journal=Endoscopy |volume=32 |issue=6 |pages=477–80 |year=2000 |pmid=10863916 |doi=] Also, clips that open and close (as opposed to single-deployment) have also been developed (Resolution Clip, Boston Scientific [cite web |url= http://www.bostonscientific.com/med_specialty/deviceDetail.jsp?task=tskBasicDevice.jsp&sectionId=4&relId=7,334,335,336&deviceId=16057&uniqueId=MPDB4329| title= Resolution Clip |accessdate=2007-05-15 |format= |work= ] ), and also facilitate the appropriate location of deployment. cite journal |author=Jensen DM, Machicado GA, Hirabayashi K |title=Randomized controlled study of 3 different types of hemoclips for hemostasis of bleeding canine acute gastric ulcers |journal=Gastrointest. Endosc. |volume=64 |issue=5 |pages=768–73 |year=2006 |pmid=17055872 |doi=10.1016/j.gie.2006.06.031]

When a treatable lesion is identified on endoscopy (such as a bleeding vessel), an endoclip can be inserted through the channel of the endoscope until the sheathed clip is visible on the endoscopic image, and the handle for deployment handed to the nurse assistant. The clip is unsheathed by retraction at the handle, positioned, and "fired" by the assistant to treat the lesion.

Applications of endoclips

Gastrointestinal bleeding

Endoclips have found a primary application in hemostasis (or the stopping of bleeding) during endoscopy of the upper (through gastroscopy) or lower (through colonoscopy) gastrointestinal tract. Many bleeding lesions have been successfully clipped, including bleeding peptic ulcers, Mallory-Weiss tears of the esophagus, cite journal |author=Yamaguchi Y, Yamato T, Katsumi N, Morozumi K, Abe T, Ishida H, Takahashi S |title=Endoscopic hemoclipping for upper GI bleeding due to Mallory-Weiss syndrome |journal=Gastrointest. Endosc. |volume=53 |issue=4 |pages=427–30 |year=2001 |pmid=11275881 |doi=10.1067/mge.2001.111774] Dieulafoy's lesions, cite journal |author=Teo EK, Fock KM |title=Dieulafoy's disease treated by endoscopic haemostatic clipping |journal=J. Gastroenterol. Hepatol. |volume=13 |issue=3 |pages=320–1 |year=1998 |pmid=9570248 |doi=] stomach tumours, cite journal |author=Cheng AW, Chiu PW, Chan PC, Lam SH |title=Endoscopic hemostasis for bleeding gastric stromal tumors by application of hemoclip |journal=Journal of laparoendoscopic & advanced surgical techniques. Part A |volume=14 |issue=3 |pages=169–71 |year=2004 |pmid=15245670 |doi=10.1089/1092642041255522] and bleeding after removal of polyps. cite journal |author=Letard JC, Kaffy F, Rousseau D, Nivet JM |title= [Post-polypectomy colonic arterial hemorrhage can be treated by hemoclipping] |language=French |journal=Gastroenterol. Clin. Biol. |volume=25 |issue=3 |pages=323–4 |year=2001 |pmid=11395682 |doi=] Bleeding peptic ulcers require endoscopic treatment if they show evidence of high risk stigmata of re-bleeding, such as evidence of active bleeding or oozing on endoscopy or the presence of a visible blood vessel around the ulcer. cite journal |author=Sung JJ, Chan FK, Lau JY, Yung MY, Leung WK, Wu JC, Ng EK, Chung SC |title=The effect of endoscopic therapy in patients receiving omeprazole for bleeding ulcers with nonbleeding visible vessels or adherent clots: a randomized comparison |journal=Ann. Intern. Med. |volume=139 |issue=4 |pages=237–43 |year=2003 |pmid=12965978 |doi=] cite journal |author=Lau JY, Sung JJ, Lee KK, Yung MY, Wong SK, Wu JC, Chan FK, Ng EK, You JH, Lee CW, Chan AC, Chung SC |title=Effect of intravenous omeprazole on recurrent bleeding after endoscopic treatment of bleeding peptic ulcers |journal=N. Engl. J. Med. |volume=343 |issue=5 |pages=310–6 |year=2000 |pmid=10922420 |doi=] The alternatives to endoscopic clipping of peptic ulcers are thermal therapy (such as electrocautery to burn the vessel causing the bleeding), or injection of epinephrine to constrict the blood vessel. Comparative studies between endoclips and thermal therapy make the point that endoclips cause less trauma to the mucosa around the ulcer than electrocautery, cite journal |author=Cipolletta L, Bianco MA, Marmo R, Rotondano G, Piscopo R, Vingiani AM, Meucci C |title=Endoclips versus heater probe in preventing early recurrent bleeding from peptic ulcer: a prospective and randomized trial |journal=Gastrointest. Endosc. |volume=53 |issue=2 |pages=147–51 |year=2001 |pmid=11174282 |doi=] but no definitive advantage to either approach has reached consensus by gastroenterologists. cite journal |author=Lin HJ, Hsieh YH, Tseng GY, Perng CL, Chang FY, Lee SD |title=A prospective, randomized trial of endoscopic hemoclip versus heater probe thermocoagulation for peptic ulcer bleeding |journal=Am. J. Gastroenterol. |volume=97 |issue=9 |pages=2250–4 |year=2002 |pmid=12358241 |doi=] cite journal |author=Kovacs TO, Jensen DM |title=Endoscopic treatment of ulcer bleeding |journal=Current treatment options in gastroenterology |volume=10 |issue=2 |pages=143–8 |year=2007 |pmid=17391629 |doi=]

Other applications

Endoclips have also found an application in preventing bleeding when performing complicated endoscopic procedures. For example, prophylactic clipping of the base of a polyp has been found to be useful in preventing post-polypectomy bleeding, especially in high-risk patients or patients on anticoagulant medications. cite journal |author=Friedland S, Soetikno R |title=Colonoscopy with polypectomy in anticoagulated patients |journal=Gastrointest. Endosc. |volume=64 |issue=1 |pages=98–100 |year=2006 |pmid=16813811 |doi=] In addition, clips can be used to close perforations of the gastrointestinal tract, that may have been caused by complicated therapeutic endoscopy procedures, such as polypectomy, or by the endoscopic procedure itself. cite journal |author=Shimizu Y, Kato M, Yamamoto J, Nakagawa S, Komatsu Y, Tsukagoshi H, Fujita M, Hosokawa M, Asaka M |title=Endoscopic clip application for closure of esophageal perforations caused by EMR |journal=Gastrointest. Endosc. |volume=60 |issue=4 |pages=636–9 |year=2004 |pmid=15472698 |doi=] Clips have also been used to secure the placement of endoscopic feeding tubes, cite journal |author=Frizzell E, Darwin P |title=Endoscopic placement of jejunal feeding tubes by using the Resolution clip: report of 2 cases |journal=Gastrointest. Endosc. |volume=64 |issue=3 |pages=454–6 |year=2006 |pmid=16923504 |doi=10.1016/j.gie.2006.02.051] and to orient the bile duct to assist with endoscopic retrograde cholangiopancreatography, a procedure used to image to bile duct.cite journal |author=Scotiniotis I, Ginsberg GG |title=Endoscopic clip-assisted biliary cannulation: externalization and fixation of the major papilla from within a duodenal diverticulum using the endoscopic clip fixing device |journal=Gastrointest. Endosc. |volume=50 |issue=3 |pages=431–6 |year=1999 |pmid=10462673 |doi=10.1053/ge.1999.v50.97369]

afety

Endoclips have been seen to dislodge between 1 and 3 weeks from deployment, cite journal |author=Binmoeller KF, Grimm H, Soehendra N |title=Endoscopic closure of a perforation using metallic clips after snare excision of a gastric leiomyoma |journal=Gastrointest. Endosc. |volume=39 |issue=2 |pages=172–4 |year=1993 |pmid=8495838 |doi=] although lengthy clip retention intervals of as high as 26 months have been reported. Endoclips are believed to be safe and no major complications (such as perforation or impaction) have been reported with them, although concern has been raised about blocking the outflow of the bile duct if clips are deployed in the duodenum.

References