Endoscopic submucosal dissection

of the stomach

Professor, Department of Surgery, Institute of Digestive Disease

Director, CUHK Jockey Club Minimally Invasive Surgical Skills Center

Director, CUHK Chow Yuk Ho Technology Center for Innovative Medicine

Assistant Dean (Ext Affairs), Faculty of Medicine, The Chinese University of Hong Kong

Philip WY CHIU MD(CUHK), MBChB(CUHK), FRSCEd, FCSHK, FHKAM(Surg)

Gastric cancer: 2nd commonest

cancer worldwide 74% of the gastric cancers in the world occur in Asia!

Advanced Stage GI Cancers

• Usually treated by radical surgery followed with adjunctive chemotherapy (and / or) radiotherapy

• Grave prognosis with limited survival

Early gastric cancer Excellent prognosis

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Italy Italy UK GermanyNetherlands Spain France USA Japan Japan Japan

5 y

r su

rviv

al

%

mucosa submucosa

Axon et al Lancet 1997

Early gastric cancers – difficult

to recognize under WLE

• High index of suspicion • Ample time for endoscopic examination • Image Enhanced Endoscopy (IEE) - NBI

Early gastric cancer Treatment options

EMR / ESD Laparoscopic Gastrectomy

Local treatment (Minimal risk of LN

metastasis

Loco-regional (high risk of LN

metastasis)

Risk of lymph node metastasis All cases of intramucosal cancers

Total LN % Diff. LN % Undiff LN %

< 10mm 357 4 1.1 257 0 0 100 4 4.0

< 20mm 767 4 0.5 455 0 0 312 4 1.3

< 30mm 927 10 1.1 518 0 0 409 10 2.4

> 31mm 965 47 4.9 417 7 1.7 548 40 7.3

Total 3016 65 2.2 1647 7 0.4 1369 58 4.2

Overall risk of LN metastasis for T1m: 2.2% Differentiated T1m: 0.4% Undifferentiated T1m: 4.2% Intramucosal EGC without ulcer: 0%

Gotoda et al. Gastric cancer 2000

Submucosal tumors – Risk of nodal metastasis

SM Total LN % Diff LN % Undiff LN %

< 10mm 99 8 8.1 70 6 8.6 29 2 6.9

< 20mm 437 56 12.8 266 32 12.0 171 24 14.0

< 30mm 567 106 18.7 344 56 16.3 223 50 22.4

> 31mm 743 130 17.5 411 92 22.4 332 38 11.4

Total 1846 300 16.3% 1091 186 17.0% 755 114 15.1%

Gotoda et al. Gastric cancer 2000

For submucosal carcinoma, overall risk of LN metastasis is > 15% Gastrectomy (LAG) should be recommended!

Advantages of Endoscopic Resection

• Local curative intent treatment

• Organ preservation – Function of the organ preserved

– Better quality of life

– Less post-gastrectomy syndromes

• Better postoperative outcome – Shorter hospital stay

– Early return of GI function

Chiu PW. GIE 2006

Endoscopic submucosal dissection

(ESD)

• En-bloc resection of early gastric cancer – Ensure clearance of resection margins

– Complete specimen for histopathology

Oda et al Dig Endosc 2005

EMR vs ESD for treatment of Early

Gastric Cancers EMR /

ESD No of patient

En-bloc resection Post ER bleeding

Perforation

Local re

curre

nce

Size of the EGC < 10mm > 10mm > 10mm

Watanabe et al

EMR 125 91.3% 63.6% 0% 3.0% 9.1%

ESD 120 92.9% 91.3% 0% 5.4 3.3%

Oka et al

EMR 825 61.9% 27.0% 7.6% 4.8% 4.4%

ESD 195 95.1% 94.4% 22.6% 8.7% 0%

Tanabe et al

EAM 359 52.1% 3.6% 3.3% 4.2%

ESD 421 92.9% 6.3% 3.3% 0.2%

ESD vs Gastrectomy for treatment

of EGC ESD (74) Gastrectomy (40) p

Median FU (months) 27.0 (1-65) 77.6 (1-180) < 0.001

Median OT Time 89.6 (45-360) 265 (150-360) < 0.001†

Blood loss (mls) 0.02 (0-1) 141.6 (0-1400) < 0.001†

Need of transfusion 1 (1.4%) 4 (10.0%) 0.056

Hospital stay 3 (2-10) 9.9 (6-26) < 0.001†

Complication 4 (5.4%) 13 (32.5%) < 0.001†

Reactionary bleeding 3 0

Anastomotic leak 0 0

Wound infection 0 3

ESD perforation 1 0

Intraabdominal collection 0 2

Chiu PW et al Surg Endosc 2012

ESD vs Gastrectomy - 3 year

survival

Log rank test p = 0.443

Chiu PW et al Surg Endosc 2012

Hospital Authority Hong Kong

Audit on Upper GI ESD 2010-2013

Teoh AY, Chiu PW, Chan FK et al

Total: 187

Guidelines on management of early GI cancers under Hospital Authority Head Office • Preclinical training workshop (with animal hands-

on) • Performance of ESD under proctorship

Difficulties in starting ESD

Teoh AY, Chiu PW, et al Surg Endosc 2009

Gastroenterologists (6) Surgeons (14) p

Mean size of specimen 2.67 +/- 1.17 2.69 +/- 11.49 0.695

Mean procedural time (min)

Gastric ESD 47.17 +/- 21.54 53.21 +/- 26.28 0.627

Esophageal ESD 25 +/- 7.07 34 +/- 5.48 0.124

Perforation 20 (62.5%)

Gastric 2 11 0.122

Esophageal 2 3 1

Procedure related mortality 1 1 0.521

Endoscopic multi-tasking platforms

EndoMaster

M.A.S.T.E.R.: Master And Slave Transluminal Endoscopic Robot Developed by Prof Lawrence Ho (National University Singapore) Prof Louis Phee (Singapore Nanyang Technological University)

Ho YK et al GIE 2010

Robotic ESD – World 1st case series

Phee SJ, Reddy N, Chiu PW et al CGH 2012

Summary

• ESD is the standard of treatment for early gastric cancer with minimal risk of nodal metastasis

• New technologies (MASTER robot) will improve the performance of endoscopic resection