Esophagus - Endoscopic Submucosal Esophageal Myotomy: 'Third Spacing' for the Endoscopist
Comments: Endoscopic submucosal esophageal myotomy or third spacing for the endoscopist.
Traditionally, gastroenterologists have been used to dealing with the space within the l lumen of the gastrointestinal tract.
In recent years, they, along with surgeons, have been riveted by the potential of natural orifice transluminal endoscopic surgery or NOTES, going beyond the gastrointestinal tract and working within the peritoneal cavity.
However, there is a space in between that has been relatively neglected and this is the focus of this video. We call this the third space. It is a potential space found under the mucosa where many important structures can be accessed.
We are going to illustrate the use of this space in an experimental technique in which we performed the equivalent of a Heller myotomy using a purely endoscopic approach.
The gold standard for the treatment of achalasia is a surgical myotomy of the lower esophageal sphincter. While pneumatic dilatation has its advantages and disadvantages, generally it does not match the longevity of the effect that can be seen with myotomy.
It has been an elusive goal of endoscopists to try and reproduce a myotomy using the endoscopic route.
Transmucosal incisions are not desirable as they will increase the risk for complications. We therefore hypothesized that by tunneling under the mucosa and working in the spce created therein, we could safely perform a robust myotomy, thereby positioning this procedure as a replacement for laparoscopic myotomy.
A submucosal lift is created in the distal esophagus using the standard approach and then a little nick is made in the mucosa using a hot needle knife allowing for the introduction of a 12 mm balloon.
Inflation of this balloon is followed by the introduction of the scope itself into this zone and you can see here the dramatic view of this space with the mucosa above and the muscular layer below.
The balloon is introduced progressively in a distal fashion allowing further dissection of this space as can be seen here.
Once the endoscope is in position, the needle knife is advanced and a myotomy is begun under direct visualization. With deeper cuts, one is able to visualize the outer longitudinal and oblique muscle layer as well. Note the almost entirely bloodless field of the operation and the clear, stunning views of the muscle layer.
The myotomy is extended from a distal to a proximal manner. The insulated tip shon in this procedure allows this procedure to be done in a controlled manner although with practice a standard needle knife is probably sufficient. One can afford to be aggressive with the assurance that at the end of the procedure, there will be no risk of mediastinal contamination with luminal contents because of the overlying intact mucosal flap.
This is a view of the myotomy and you can see the oblique fibers exposed and we are now pulling out of this space and back into the lumen. The defect in the mucosa is closed with application of standard endoscopic clips. Only two are required.
The animal is allowed to recover and is observed for one week.
After one week, a necropsy is performed. Note the complete lack of inflammation or infection in the chest cavity.
Several pigs have been done and follow up manometry showed dramatic reduction in the lower esophageal sphincter pressure. Long term studies are underway.
In conclusion, we have described a procedure that we believe provides an endoscopic equivalent of a Heller myotomy with the additional advantages of no percutaneous ports, little or no risk of vagal injury or damage to other structures and with the potential of being repeated as required to produce the desired functional effect.
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Pankaj J. Pasricha, M.D. Professor of Internal Medicine University of Texas Medical Branch Rami Hawari, MD University of Texas Medical Branch Ijaz Ahmed, MD University of Texas Medical Branch Douglas L. Brining, DVM University of Texas Medical Branch |
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Citation: Pasricha, PJ & Hawari, R. & Ahmed, I. & Brining, DVM, DL (May 21 2007). Esophagus - Endoscopic Submucosal Esophageal Myotomy: 'Third Spacing' for the Endoscopist. The DAVE Project. Retrieved Jul, 30, 2010, from http://daveproject.org/viewfilms.cfm?film_id=601 Times viewed since Feb 2006: 5893 |
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