MUSE™ SYSTEM - FAQ'S

1. Endoscopy suite or operating room?

Could be performed in an operating room or in an Endoscopy room provided that general anesthesia (and PEEP) is available.

2. How long does the procedure take?

The learning curve is fairly rapid. An experienced physician can typically perform our procedure in 1 hour.

3. General anesthesia or sedation?

Currently, General anesthesia as diaphragm paralysis is necessary.

4. Hospitalization or Outpatient?

All of our procedures to date have included one night in the hospital.

5. Follow up consultations? Is necessary to follow a specific diet?

According to your hospital policy after fundoplication surgery (which is typically clear liquids for 48 hours, graduating over two weeks to full liquids, soft food then solids). It is important to allow the staple sites to heal following the procedure.

6. Is any other device needed to perform the procedure?

No. MUSE™ system includes all devices and accessories relating to the procedure, with the exception of a standard HDMI monitor and a standard gastroscope for pre and post procedure gastroscopy.

7. Specific requirements regarding the anatomy of the patients?

Large hiatus hernia (>3cm) is one. Very skinny subjects (BMI<21) may have tissues that are too thin and outside the normal operating range of the device. Also very obese will probably be excluded.

8. Absolute Indications and Contraindications?

As the indications and contraindications of fundoplication surgery. Several conditions were excluded from our clinical studies (see full list at end of document), in particular:
  1. Hernia >3cm
  2. Failure to reduce hernia with PEEP (see Q. 11, below)
  3. Strictures or varicles in the esophagus
  4. BMI<21 or >35
  5. Non responders to PPI therapy

9. Preoperative workup?

Similar to that of a fundoplication surgery (confirmation the patient has GERD).

10. What if the patient has hernia?

Currently, Endoscopic Hiatal hernia > 3 cm.

11. How is the hernia reduced?

When the patient is in slight reverse Trendelenburg and PEEP up to 10 cm H2O is applied, the positive pressure in the chest reduces the hernia (unless it is tethered by adhesions, in which case the procedure should be aborted or converted to a laparoscopic fundoplication).

12. What is the exact position of staples at the esophagus and stomach in relation with Z-line?

It varies, but in general we attempt to staple the stomach to the esophagus in an anterior semi-circle of about 180° approximately 3cm proximal to the GE junction.

13. Do the staples include the phrenoesophageal ligament in the bite? (advised to refer to a Medigus MD)

On the leftmost quintuplet, it often does. We can estimate that from the initial tissue thickness.

14. Landmarks during the procedure?

You see the instrument coming out of the esophagus into the stomach and choose your stapling location. One approach includes rotating the scope to the left as far as you can) and then withdrawing the scope to the premeasured distance from the incisors (to ensure staples are placed 3cm form the GEJ). After the first quintuplet is placed, the next one is targeted a bit more to the right, and so on.

15. How many degrees is the fundoplication?

It varies with the anatomy of the patient. But usually it is around 180° at the staple line. It is wider at the base, of course.

16. Why partial fundoplication?

In general, multiple RCT have demonstrated that in terms of quality of life, anterior fundoplication is equally effective as a full 360° wrap. While anterior fundoplication has a somewhat lower control of acid reflux, this is compensated by the lower incidence of dysphagia.

17. Possible complications and solutions? (advised to refer to a Medigus MD)

a. In our international multi-center pivotal study that treated 69 patients we had the following complications. All these cases occurred in the first 24 procedures, prior to protocol and procedure amendments. The system and the IFU were modified to mitigate these risks and we did not see these complications in the remainder 45 procedures of the study.
  • One case of bleeding requiring transfusion 8 days post procedure. The source was never located endoscopically
  • One case of occult perforation resulting in benign pneumomediastinum. It took two weeks to reabsorb, but did not cause any other problem. We think that the pneumomediastinum was because the operator accidentally held his finger on the air insufflation button during screw insertion. Following this case, we disabled the air pump before screw insertion and did not see this complication again.
  • One case of empyema and pneumothorax. No perforation was identified, but the amylase level in the fluid was >20k. Patient recovered without surgery. The patient retched and vomited in the recovery room. An NG tube drained 200 ml of blood. Chest tube, antibiotics and clips were necessary. Patient hospitalized for 22 days. We think that the retching caused a tear at one of the stapling sites. Following this case, we added mandatory post anesthesia antiemesis and did not see this complication again.

18. Do you have any laparoscopic view of the fundoplication?

We have a lap view video of one stapling process in a pig model.

19. Is a hybrid procedure (combination of endo and lap) an option?

If the physician believes that it is appropriate for the patient.

20. Is it possible to do lap Nissen after MUSE™?

Yes. We know of four such cases, one from Austria and one from Australia and two in the US.

21. How do you control your end results?

We suggest annual follow ups for all the patients in the studies with GERD-HRQL scores.

22. Is there any questionnaire to check patient satisfaction?

The GERD-HRQL was used in our Pivotal study. 73% of subjects had ≥50% reduction in GERD HRQL score at 6 months.

23. Is there a protocol for postoperative follow up?

Same as after a laparoscopic fundoplication

24. What are the proposed solutions in case of failure? (advised to refer to a Medigus MD)

It depends on how the failure is defined. A lap fundoplication would not be precluded by a MUSE procedure. Repeating the MUSE™ procedure has not yet been studied clinically.

25. When can we expect the first publication?

The manuscript with 6-month results of the international multi-center pivotal study was published online in August 2014 and appeared in Surgical Endoscopy in Jan. 2015. A follow-on article with 4+ year results of the pivotal study is now available online and appears in Surgical Endoscopy, November 2015. In addition, an article with 5 year results on 13 patients that were treated as a part of a pilot study which preceded the international pivotal study is available online and was published in Surgical Endoscopy in Dec. 2015.

26. What is your follow up until now?

We have 5 year follow up on the 13 subjects from the pilot study in India. This article is now available online through Surgical Endoscopy and will appear in print soon. The conclusion was Throughout the follow up period, GERD-HRQL scores were normal (<10) in all but one patient. All patients would agree to do the procedure again. None reported dysphagia. Combining respondents at 4 and 5 years to account for all patients, 54% (7/13) had eliminated and another 23% (3/13) reduced PPI use ≥50% (77% total). At 5 years, the MUSE™ procedure remained effective to improve QOL in moderate to severe GERD without causing dysphagia. There was no deterioration of results after 3rd year.

27. Do you have any experience with patients with upper respiratory symptoms and no heartburn (patients have chronic cough and pharyngitis)?

No, but these types of patients may be appropriate candidates. They are not excluded under the current contraindications.

28. How do you train the doctors?

Our training program is comprised of a theoretical didactic presentation, operation instructions with the device itself (on a simulator model),and performing the complete procedure on an In-vivo porcine model. Usually, the entire program is accomplished in a single day.

29. What is the learning curve of the procedure?

It depends on the experience with advanced endoscopic techniques. An endoscopist experienced with therapeutic gastroscopies (like rubber band ligation of bleeding varices, polypectomies and biopsies, etc.) or ERCP should have a short learning curve of 3-5 procedures.

30. Can I use my own endoscopy console (tower) instead of the Medigus console, even with the use of some adaptors?

The MUSE™ endoscope is only supported by the MUSE™ console since many technologies inside the endoscope (e.g., the ultrasound) are controlled by electronics inside the console. The console also displays special graphics on the monitor based on the information received from the sensors in the endoscope. In short, the MUSE™ console is the "brain" behind the different unique technologies inside the endoscopes and has much more functionality than a standard endoscopy tower. Unfortunately, no adapter can bridge the gap of the additional technologies at this point.

31. How can I be sure that the process does not take blood vessels? (advised to refer to a Medigus MD)

If done correctly, no named blood vessels are involved. The only blood vessel at risk is the left gastric artery, but no staples should be placed in its vicinity. All quintuplets should be placed in the fundus, or to the left of the celiac axis, including the left gastric artery. It can sometimes be seen as a pulsation in a fold hanging from the cardia to the right side, along the lesser curve of the stomach. No staples should be placed in the lesser curve area. Unlike Nissen, the anterior fundoplication also does not pull on the short gastric arteries either, (vasa brevia) and they too cannot be injured. The rightmost quintuplet, which is central, may cause injury to the anterior vagus nerve, but never to the posterior vagus nerve. Even if the anterior vagus is injured, there are no functional consequences (this is another advantage of anterior fundoplication vs. Nissen - bilateral vagal injury with resulting pyloric dysfunction is impossible).

32. Does the MUSE™ take muscles also within the staplers? (advised to refer to a Medigus MD)

That is not the intention. The MUSE™ system does not take typically capture muscles within the staplers, but it might take the tendon of the left crus.

33. Can the MUSE™ procedure be done in patients with prior surgical fundoplications that have loosened with recurrent symptoms?

Currently we advise against this until we have had time to further research the implications.

34. After the MUSE™ procedure, what is the mechanism that prevents reflux? What is really closing the way back?

The MUSE™ procedure attempts to prevent reflux in the same manner as lap fundoplication (more precisely, Thal-Dor anterior partial fundoplication surgery).
The MUSE™ procedure may prevent the reflux of gastric content to the esophagus by two mechanisms:
1. The functional flap valve is reconstructed at the gastro-esophageal junction to prevent the reflux from the stomach towards the esophagus
before and after MUSE procedure

>2. Partial Fundoplication of 180° – Partial rap of the gastric fundus around the lower part of the esophagus creates a valve like mechanism that closes the lower part of the esophagus when the stomach fills with food.

35. What are the complications of hitting or injury the nerves present in Esophagus specially Vagus nerve?

The posterior vagus nerve is far from the stapling site, and it cannot be injured by anterior fundoplication. The anterior nerve may be pierced by the staples, but it will not likely to be completely severed. However, the anterior nerve is redundant. As long as the posterior nerve is not injured, gastric emptying remains normal (in 360 degree wrap, both nerves are at risk, and this is a known complication of LNF).

36. What is the FDA Clearance/Intended Use/Indications for Use of the MUSE™ System?

The MUSE™ Endoscopic Stapling System is intended for endoscopic placement of surgical staples in the soft tissue of the esophagus and stomach in order to create anterior partial duplication for treatment of symptomatic chronic Gastro Esophageal Reflux Disease in patients who require and respond to pharmacological therapy.

37. What are the “common” adverse events expected to appear?

In our pivotal study, the most common AE were:
  • Chest pain (22% of subjects) and
  • Sore throat (21%)
There were no reports of dysphagia, bloating or inability to belch.
At the first week follow up visit almost all patients were back to normal activity.

38. What is the FDA Clearance/Intended Use/Indications for Use of the MUSE™ system?

The MUSE™ Endoscopic Stapling System is intended for endoscopic placement of surgical staples in the soft tissue of the esophagus and stomach in order to create anterior partial duplication for treatment of symptomatic chronic Gastro Esophageal Reflux Disease in patients who require and respond to pharmacological therapy.

39. Can patients be treated who have had gastric bypass surgery? If yes, how much fundus would need to be available to treat?

This is best shown visually with the distal tip of the device. The device requires ample space for the distal tip to articulate against the staple cartridge. We have not yet done studies including gastric bypass patients.

40. How can I get trained/get the product?

Medigus is preparing to scale up commercially in a responsible and disciplined way to ensure the best possible patient outcomes. We are in the process of enrolling patients into an international Registry. We have most of our sites selected and well down the path of IRB, contracts and budget negotiations. However, we are open to new sites who can demonstrate [they have the resources to gain approval and enroll quickly]. We do not typically train a site until the process is underway and a procedure date is within site. Alternatively, we can discuss other options for getting the devices into your center so you can treat patients outside of the registry.

41. What is the purpose of the ultrasound?

The ultrasound helps you to “see” when direct vision is no longer possible. It gives you information about the thickness of tissue that is captured between the distal tip and the staple cartridge, which is critical to the safe operation of our device and to a secure staple placement.

42. What am I looking at on the monitor in the graphics mode?

The monitor is giving you critical information such as the amount of compression force of our device on the tissues, if the alignment pin is properly positioned, if the screws are anchored into the nuts and if the tissue thickness is within the 1.4 – 1.6mm range required for secure staple placement.

43. Why do you need to use an alignment pin and screws?

It is very important to align the device in order to have properly formed staples. The concave shape of the distal tip provides some initial alignment of the stapler anvil and the cartridge which contains the staples. The alignment pin engages with a funnel to provide additional alignment. The anvil screws then engage with nuts within the cartridge to provide final alignment and compression of the tissue.

44. Is the MUSE System reusable?

The MUSE console is reusable, but the MUSE Endostapler is disposable and intended for use on a single patient to eliminate all risk of cross contamination between patients.