Recent advances in third space

1. ADVANCES IN THIRD
SPACE ENDOSCOPY
DR B MOHAMMED NOUFAL . MD . DM;
CONSULTANT - GASTROENTEROLGY AND INTERVENTIONAL ENDOSCOPY
ASTER MEDCITY

2. WHAT IS THE THIRD SPACE?
• Endoscopists were initially confined to the GI lumen (1st space)
• Peritoneal cavity was the surgeon’s fort (2nd space)
• Potential submucosal space holds therapeutic promises (3rd Space)

3. EVOLUTION OF THIRD SPACE ENDOSCOPY
• The capabilities of interventional gastrointestinal endoscopy have significantly
increased over the past several decades.
• The concept of submucosal endoscopy with mucosal flap safety valve has
enabled endoscopists to securely use submucosal space, or third space.
• Peroral endoscopic myotomy was the initial procedure performed utilizing
submucosal space in patients with achalasia. Subsequently, this technique has
been used successfully for removal of subepithelial tumors from the esophagus
and the stomach.

4. TECHNIQUE
• All third-space endoscopy procedures use a similar technique—a submucosal
tunnel is created, and then a myotomy is performed or a subepithelial tumor is
dissected away from the initial site of the mucosal incision
• Submucosal endoscopy is largely safe, and the occurrence of major adverse
events is uncommon. Therefore, the majority of third-space endoscopy
procedures can be performed in an endoscopy suite
• The most frequently encountered adverse events during submucosal endoscopy
include those related to insufflation, bleeding, and perforations.

5. SCOPE OF THIRD SPACE ENDOSCOPY

6. EQUIPMENTS
Endoscope GIF-HQ190, Olympus (Outer diameter of 9.2
mm, integrated water channel)
Electrosurgical Generators VIO 300 D, Erbe ESG-300, Olympus
Carbon Dioxide Insufflators UCR, Olympus CO2MPACT, US Endoscopy
Low-Flow Gas Tube or Extra Low–Flow Gas
Tube
MAJ-1742, Olympus
Low-Flow Gas Tube or Extra Low–Flow Gas
Tube
MAJ-1816, Olympus
Coagulation Forceps Coagrasper (FD-410/411UR/412LR, Olympus)
Electrosurgical Knives Triangle Tip Knife (KD-640L, Olympus)
HybridKnife (20150-060, Erbe)
Triangle Tip Knife J (KD-645L, Olympus)
HookKnife (KD-620LR, Olympus)
ITknife2 (KD-611L, Olympus)

7. PERORAL ENDOSCOPIC MYOTOMY
Peroral endoscopic myotomy. (A) Entry to submucosal space. (B)
Submucosal tunneling. (C) Endoscopic myotomy, with a total length of 10
cm. (D) Long endoscopic myotomy of inner circular muscle bundles,
leaving the outer longitudinal muscle layer intact. (E) Closure of mucosal
entry (Adopted from Inoue et al. Endoscopy 2010;42:265-271).16

8. PERORAL ENDOSCOPIC MYOTOMY
POEM procedure ,
A mucosal entry,
B creating submucosal
tunnel (esophageal body),
C creating submucosal
tunnel (LES),
D after creating submucosal
tunnel,
E after myotomy,
F closure of mucosal entry

9. POEM: OUTCOMES

10. GASTRIC PERORAL ENDOSCOPIC MYOTOMY
(G-POEM)
• Refractory Gastro-paresis is problematic in diabetics and post-op
patients
• Other modalities (Diet, pro-kinetics, Botox) have limited success
• Impaired motility and pyloro-spasm
• Myotomy is lucrative approach

11. GASTRIC PERORAL ENDOSCOPIC MYOTOMY
(G-POEM)
Steps of G-POEM
procedure. (A) Selection
of targeted gastric wall
and creation of
submucosal bleb. (B)
Longitudinal mucosal
incision. (C) Creation of
submucosal tunnel. (D)
Identifying the PMR. (E)
Endoscopic
pyloromyotomy. (F)
Mucosal access closure
using clips.

12. GASTRIC PERORAL ENDOSCOPIC MYOTOMY
(G-POEM)

13. ZENKER’S DIVERTICULUM
• Usually managed by endoscopic division of
the septum between the esophageal and
diverticular lumen
• An endoscopic approach is preferred over
surgical treatment since the former is
associated with fewer complications,shorter
procedure duration and shorter hospital
stay
• However symptoms recur in approximately
11% due to incomplete division of septum

14. ZENKER’S DIVERTICULUM PER ORAL ENDOSCOPIC
MYOTOMY (Z-POEM) & SEPTOTOMY
Standard per-oral endoscopic myotomy (Z-
POEM) technique. (A) A ZD (yellow arrow
Zenker’s diverticulum; blue arrow septum) is
identified. (B) A mucosal bleb is created 2 cm
above the septum. (C) A submucosal tunnel is
created using spray coagulation and injection
of saline/indigo carmine solution via the
pump. Once the septum is exposed, the
septotomy is performed using an endoscopic
submucosal dissection knife with an insulated
tip. (C–E) The septotomy is extended until the
longitudinal muscle fibers of the esophagus
proper are exposed (red arrow). (F) The
mucosal incision is closed using through-the-
scope clips

15. ESD & EMR
• For epithelial lesions
• EUS to look for depth of penetration
• Smaller lesions best treated with EMR
• ESD offers en bloc removal, good HPE, low recurrence

16. ENDOSCOPIC MUCOSAL RESECTION (EMR)
The process of endoscopic
mucosal resection (EMR). (A)
The lesion before resection. (B)
Inject saline solution at the
submucosa. (C) Release the
snare, then re-tighten and
resect the lesion. (D) The
wound after resection. (E) Seal
the wound with metallic clips.
(F) The lesion.

17. ENDOSCOPIC SUBMUCOSAL DISSECTION
(ESD)
Endoscopic submucosal
dissection (ESD) technique in
early gastric cancer located at
the incisura. (A) Mucosal
lesion, spanning approximately
2 cm in white light view. (B)
Mucosal lesion, giving cause
for concern, in narrow band
image view. (C) Perimeter of
planned incision marked with
electrocautery. (D) After
circumferential incision. (E)
After completion of dissection.
(F) Resection specimen 34 mm
x 29 mm.

18. ESD VS EMR IN GASTRIC CANCER

19. ESD VS EMR IN CRC

20. Endoscopic full-thickness resection (EFTR)
procedures. (A, B) An oval submucosal tumor was
located in the middle third of stomach, and EUS
[mini-probe] showed it was homogenously
hypoechoic orginating from muscularis propria.
D) Circumferential incision and deep submucosal
dissection. (E, F) After complete removal with full-
thickness resecion, the defect was closed with
and an endoloop. (G) The endoscopic apperarance
of the wound at 3 month after EFTR

21. SUBMUCOSAL TUNNELING ENDOSCOPIC
RESECTION (STER)
• ESD and EMR: Epithelial lesions
• ESD sub-optimal in c/o MP involvement
• Invented by Xu et al (2012)

22. SUBMUCOSAL TUNNELING ENDOSCOPIC
RESECTION (STER)
Submucosal tunneling endoscopic
resection (STER) to remove an esophageal
submucosal tumor (SMT) originating from
the muscularis propria (MP) layer. (A) An
esophageal SMT was detected by
endoscopy. (B) Submucosal injection at 5
cm proximal to the tumor and a 2-cm
longitudinal mucosal incision was made as
the tunnel entry. (C) Tumor dissection and
exposure.
(D) Submucosal tunnel after tumor
(E) Closure of the tunnel entry with several
clips. (F) Complete resection of the
esophageal SMT

23. TAKE HOME MESSAGE
• 3rd space is the Pandora’s box
• Learning curve for all procedures
• Technical & accessory requirements
• Cost may be a limiting factor
• Useful non-invasive alternative for many surgical conditions

24. THANK YOU