1. Ryan D. Torrie, M.D. November 3, 2012 ARGON PLASMA COAGULATION

2. SUMMARY Introduction Required equipment How it works Indications Complications How to use it Start up cost

3. INTRODUCTION APC is a fairly new technology First used in open surgery Adapted to endoscopy in early 1990s in Germany 1 It is easy to use It has multiple indications and rare complications APC is relatively inexpensive It is a nice tool to have in your Endo Toolkit

4. EQUIPMENT Required equipment Electrosurgical generator Argon gas APC Probe Footswitch

5. HOW IT WORKS APC Unit delivers a high frequency current to tissue via ionized argon gas Depth of penetration directly dependent on 1.Power setting 2.Duration of pulse 3.Probe distance from tissue At low setting of 40 W x 5 sec = 1.5 mm penetration At high setting 100 W x 20 sec = 5 – 6 mm penetration 2

6. APC UNIT Tissue Tungsten Electrode Teflon Probe with ceramic tip Operative Distance 2-10 mm Argon Plasma Beam Coagulation Zone 0.8-3 mm depth Ar I HF Neutral Electrode

7. INDICATIONS Hemostatic control Arteriovenous malformations Postpolypectomy bleeding Variceal bleeds Bleeding ulcers Bleeding diverticular disease Bleeding malignancy Portal gastropathy

8. INDICATIONS Ablative uses Destruction of residual adenomatous tissue Ablative polypectomy Barret’s esophagus Eradication rates from 62% 3 to 99% 4 Post operative/stenting strictures Endoscopic Tx of Zenker’s diverticulum Treat early small gastric cancers

9. INDICATIONS Ablative uses Radiation proctopathy Gastric antral vasacular ectasia (GAVE) or watermelon stomach Often a diffuse patchy pattern ideal for APC Palliative uses for advanced colonic malignancies Avoid stenting with associated complications Debulking treatments preventing obstruction Achieve hemostasis when needed

10. COMPLICATIONS Bowel distension Perforation (<1%) Argon gas can permeate bowel wall leading to Pneumomediastinum Pneumoperitoneum Submucosal emphysema Delayed bleeding Transient fever and chest pain

11. ADVANTAGES OF APC Safe and consistent penetration depth Controlled tissue ablation Limited collateral tissue damage Enhanced adenoma destruction Decrease recurrence from 54-100% 5 Rapid hemostasis, improved visibility with argon flow No contact is required Simple and affordable to operate compared with laser

12. LIMITATIONS OF APC Start up costs No mechanical pressure for hemostasis May adhere to eschar or tissue ‘buried’ metaplastic Barret-type glands

13. HOW TO USE IT Apply ground pad Ensure appropriate settings Power 40-100 Watts Argon flow 0.1-8.0 L per min Keep flow around 1 litre per minute to avoid distension Insert and purge the probe Activate pedal and sweep over the target area Keep probe 2-10 mm from tissue Intermittent aspiration as infusing argon gas

14. ARTERIOVENOUS MALFORMATIONS

15. RESIDUAL ADENOMATOUS TISSUE

18. CONCLUSION APC has multiple uses in ablative and hemostatic therapies APC is a fairly new and relatively affordable technology It is simple and safe to use APC has carved out an expanding niche in endoscopic practice

19. QUESTIONS

20. REFERENCES 1.Grund K E, Storek D, Farin G, “ Endoscopic argon plasma coagulation (APC) first clinical experiences in flexible endoscopy “, Endosc Surg Allied Technol (1994); 2:pp. 42-46. 2.Farin G, Grund K E., “Argon plasma coagulation in flexible endoscopy: the physical principle“, Endosc Digest (1998); 12: pp. 1521-1527. 3.Kahaleh M, Van Laethem J L, Nagy N, et al., “ Long term follow-up and factors predictive of recurrence in barret’s esophagus treated by argon plasma coagulation and acid suppression ”, Endoscopy(2002); 34: pp. 950-955. 4.Madisch A, Miehlke S, Bayerdorffer E, et al., “ Long-term follow-up after complete ablation of Barret’s esophagus with argon plasma coagulation ”, World J Gastroenterology (2005); 11:pp. 1182-1186. 5.Zlatanic J, Waye J D, Kim P S, et al., “ Large sessile colonic adenomas: Use of argon plasma coagulator to supplement piecemeal snare polypectomy ”, Gastrointest Endosc (1999); 49: pp. 731-735