Endo Conference: Large Polypectomy & EMR

Transcription

1 Endo Conference: Large Polypectomy & EMR Dr. Whang Feb 3, 2015 VOGELGRAM: genetic pathway of colorectal cancer & genes affected by point mutations

2 Outline I. Baseline Colonoscopy II. Colon Polyps III. Polyp Classification Schemes Paris classification vs. Simple IV.Polypectomy Snare Loop Polypectomy Endoscopic Mucosal Resection Endoscopic Submucosal Dissection

3 I. Baseline Colonoscopy o High quality: good inspection/clearing of colon 1. minimal fecal residue 2. reaches cecum 3. minimal withdrawal time 6-10 minutes o Goal: complete colon polypectomy decrease incidence & mortality of colon cancer o Findings help determine postpolypectomy surveillance intervals

4 II. Colon Polyps ADENOMAS Tumors of benign neoplastic epithelium --- have malignant potential Polypectomy INTERRUPTS adenoma-carcinoma sequence PREDICTORS OF FUTURE advanced adenomas (size >=1cm, villous, HGD) OR cancer 1Multiple polyps (>=3 adenomas) 2Size (>=1cm) 3Villous histology 4High-grade dysplasia

5 III. Polyp Classification Simple Type of Polyp Pedunculated Sessile Flat Definition Head connected to stalk/pedicle Broad-base, NO connecting stalk NOT protrude, NOT raised

6 III. Polyp Classification cont d Paris Classification (2002) International meeting: endoscopists, surgeons, pathologists Goal: classify superficial neoplastic lesions (esophagus, stomach, colon) Superficial neoplastic lesion = morphologic appearance during endoscopy depth of the lesion does not extend beyond submucosa (muscularis propria NOT INFILTRATED) o o Dysplasia Polyps: hyperplastic, serrated adenoma, adenoma o Carcinoma invades lamina propria 1. limited to mucosa (esophagus, stomach) 2. submucosa (colon)

7 III. Polyp Classification cont d Surface pattern: granular VS. non-granular Classifications morphology + surface pattern help predict histopathology What is associated with deeper submucosal invasion (SMI)? 1) depressed 2) non-granular

8 IV. Polypectomy Polyp Size Removal Technique Small (<5 mm) Cold Forceps Biopsy *resection Larger >7 8 mm Electrocautery Monopolar current: electrode in instrument tip > body > grounding plate (leg, thigh) Bipolar electrodes in tip (active and return) At least 1 cm Snare Loop Polypectomy +/- Adjuvant electrocautery Submucosal injection Large nonpolypoid, sessile lesions 1. Difficult to resect by EMR early Ca>2 cm residual lesion>1 cm 2. Nonlifting sign Endoscopic Mucosal Resection (EMR) Endoscopic Submucosal Dissection (ESD) 1. Cautery (disrupt tissue) 2. Coagulation (thermal energy for hemostasis) Elevate with submucosal injection + snare resection with electrocautery Dissect below lesion in the fluid expanded submucosal plane --- confirm have clear margins (edge, depth)

9 IVA. Snare Loop Polypectomy Goal: en bloc (single piece) resection o accurate staging o determine level of invasion o giant polyp --- consider injection 4-8mL 1:10,000 epinephrine polyp head and stalk (decrease polyp size) Failed complete endoscopic resection (highest independent predictor is previous intervention) o after electrocoagulation, if there is residual tissue fibrosis may be nonlifting Instruments, per preference of endoscopist o Oval o Hexagonal o Barbed o Duckbill o Mini snare

10 AcuSnare Sheath length 240 cm; 7 Fr Minimum accessory channel: 2.8mm Snare size: variable Material: braided stainless steel Flexibility: firm OR soft (contains nitinol) Use with electrosurgical unit

11 Snare: Oval, Mini Oval, Crescent SnareMaster: o Single-use o Easier insertion into channel o Increased tactile feel prevent premature cutting of lesion o 4 shapes 1) Soft uses less force to open/close loop 2) Oval thicker wire cut slow & controlled 3) Crescent thin wire 0.3mm cut fast & clean 4) Spiral twisted wire prevent mucosal slipping Min channel size = 2.8cm (2cm for crescent)

12 IVA. Snare Loop Polypectomy cont d Technique Position polyp at 5 to 7 o clock Position snare loop around base of polyp (extends out of plastic catheter) o If pedunculated: want visible stump, position snare loop on pedicle a third or halfway from polyp base (benefit: can treat easier if immediate bleed postpolypectomy) Prior to snare resection --- o Advance catheter tip to polyp base prevents snare from slipping over polyp head during snare closure o Tips to aid in single/complete resection 1. Change volume air insufflation in lumen 2. Retroflex endoscope (for lesions behind a fold) 3. Change patient position (change polyp position, prevent fluid pooling) 4. Give antispasmodic (glucagon 0.5 mg IV) Prior to cautery --- o Position polyp in center of lumen & loosen snare slightly stretch submucosa away from muscularis propria, serosa (loosening helps prevent trapping muscularis propria)

13 IVB. Endoscopic Mucosal Resection (EMR) Injection-assisted polypectomy; Inject & cut technique Purpose: remove large nonpolypoid OR sessile lesions o En bloc EMR: safe & reliable if lesion <=2cm Proximal colon: 2cm Distal colon, Rectum: 2.5cm o Piecemeal EMR: no defined size limit Injectable fluids --- density sustain submucosal bleb o Normal Saline (most common, simple, safe, affordable) o Blue Dyes (indigo carmine, methylene blue) *one source noted this is the standard 1. Define polyp border 2. Confirm extent of submucosal bleb 3. Confirm safe plane for resection since submucosal areolar tissue is avid for the dye o 1mL 1:10,000 epinephrine + 8mL saline o Other fluids evaluated: dextrose, glycerol (hypertonic solution 10% glycerol + 5% fructose in NS), colloid-based (hydroxethyl starch, succinylated gelatin, albumin, autologous blood), hyaluronic acid Postop: Consider clear liquid diet after procedure, then resume typical diet the next day

14 IVB. EMR cont d NONLIFTING SIGN Definition: lesion does NOT lift in amplitude despite proper submucosal injection Differential 1Malignancy (i.e. carcinoma which invaded deeper level of submucosa OR muscularis propria) 2Prior biopsies/resections at specific site develop fibrosis 3NOT injecting in correct tissue plane What are the concerns? o Possible submucosal invasion o Snare may trap muscular propria risk of perforation o Risk transmural burn Next step? o Biopsy, limit this to 1 site if possible

15 IVB. EMR cont d Technique Position polyp at 5 to 7 o clock Inject fluid into submucosal space of polyp make submucosal cushion 1. Increase polyp amplitude 2. Decreased risk Postpolypectomy bleed (thought that fluid injection causes a tamponade effect; immediate bleed can be up to 11.3%) Perforation (0-1.1%) 3. Deeper & complete resection ~95-100% Snare lesion

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18 IVB. EMR cont d BLEEDING Rate % Adverse Events dependent on skill of endoscopist Inform patient: postresection bleeding risk is 1 in 150 (which can be treated endoscopically) 2 types 1Immediate bleeding = cut submucosal vessels, INSUFFICIENTLY coagulated 2Delayed bleeding = RUPTURE of injured OR coagulated submucosal vessels (within 48 hours, ~7% cases) Prevent bleeding 1Be ready to treat a bleed. Know patient s coagulation status & clotting function. 2Perform adequate submucosal injection do NOT cut/injure deeper submucosal vessels 3Obliterate vessels (coagulate, clip) that are exposed due to resection 4Strangulate vessels which supply pedunculated neoplasms (as prophylaxis) 5Do NOT transect invasive cancers

19 IVB. EMR cont d PERFORATION Rate % Adverse Events Inform patient: theoretical risk is 1 in Types 1 Immediate perforation --- due to deep resection 2 Delayed perforation --- due to coagulation necrosis wall rupture Prevent perforation 1 Use adequate volume for submucosal injection 2 Recognize nonlifting sign 3 Prior to snare resection, position snare in lumen & loosen slightly helps prevent trapping muscularis propria 4 Close any perforation IMMEDIATELY (suspected, frank, postresection site appears thin OR required excessive coagulation) 5 Do NOT perform too many large EMR s at once 6 Consider using CO2 7 Consider deflating colon after large EMR decrease pressure?bacterial SEEDING Risk is not known --- consider broad-spectrum ATB x 3 days

20 IVB. EMR cont d Piecemeal Polypectomy Evaluate for local recurrence US Multi-Society Task Force on Colorectal Cancer & American Cancer Society: Sessile adenomas removed piecemeal 1) Ensure removal in 2 6 months 2) If removal complete subsequent surveillance per judgement of endoscopist VA Affairs, Stanford University (GI Endoscopy Clin N Am 2013) Surveillance colonoscopy (@ 6 months) Evaluate prior site (scar, tattoo) NO macroscopic e/o recurrence biopsy site Macroscopic e/o recurrence repeat EMR If not amenable to curative EMR (i.e. submucosal invasive Ca) refer for surgical resection

21 IVC. Endoscopic Submucosal Dissection (ESD) Invented in Japan to treat early gastric cancer Use electrosurgical knife --- INJECT FLUID into & CONTROLLED DISSECTION through submucosal plane En bloc removal of advanced lesions Improved histologic evaluation (compared to piecemeal polypectomy) No residual polyp Requires expert endoscopist Indications: 1. Difficult to resect by EMR early Ca>2 cm residual lesion>1 cm laterally spreading 2. Nonlifting sign Adverse Events Bleeding Rate 1-2% Perforation Rate 5.5%

22 IVC. ESD cont d Olympus DualKnife Electrosurgical Knife - Knife tip is knob-shaped - Knife length is adjustable - Markers on sheath to help determine depth of cut Mixed solution: glycerol + hyaluronic acid (helps distinguish vessels)

23 References: 1. Guidelines for Colonoscopy Surveillance after Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society. Winawer S, Zauber A, Fletcher R, Stillman J, O Brien M, Levin, B, Smith R, Lieberman D, Burt R, Levin T, Bond J, Brooks D, Byers T, Hyman N, Kirk L, Thorson A, Simmang C, Johnson D, Rex D. CA Cancer J Clin 2006;56: Colon Polypectomy: A Review of Routine and Advanced Techniques. Kedia, P, Waye, J. J Clin Gastroenterol 2013; 47: Advanced endoscopic resection in the colon: recent innovations, current limitations and future directions. Tutticci N, Bourke M. Expert Rev Gastroenterol Hepatol 2014;8(2): Sleisenger and Fordtran. Chpt The Paris endoscopic classification of superficial neoplastic lesions: esophagus, stomach, and colon: November 30 to December 1, Gastrointestinal Endoscopy 2003; 58(No. 6):S3-S Endoscopic Resection of Large Colon Polyps. Kaltenbach T, Soetikno R. Gastrointest Endoscopy Clin N Am 2013; 23: ge_id=0b34e9be-5de6-4cb4-b cc ct_details_7937.jsp 10. Can Endoscopic Submucosal Dissection Technique Be an Alternative Treatment Option for a Difficult Giant Pedunculated Colorectal Polyp? Choi Y, Lee J, Lee E, Lee S, Suh J, Lee D, Kim D, Youk E. Disease of The Colon & Rectum 2013;56(5):