Gastroesophageal Reflux Disease: Endoluminal Approaches



Gastroesophageal Reflux Disease: Endoluminal Approaches


W. Scott Melvin



Many Americans report symptoms of gastroesophageal reflux (GERD). The standard therapy for these sometimes troublesome symptoms is usually medical treatment with proton pump inhibitors. Patients with persistent symptoms, those with complications of regurgitation, or those who cannot tolerate medical therapy may be recommended to have an antireflux procedure. Since the 1950s, a variety of different operative techniques have been described. In the early 1990s these traditionally open procedures were transitioned to minimally invasive surgical procedures. Currently, most patients who undergo interventional therapy for GERD are treated with a laparoscopic Nissen fundoplication. These operative interventions are associated with a low rate of mortality and morbidity, and are associated with generally good results. They are often combined with hiatal hernia repair in patients with disordered anatomy. Ideally, patients with relatively normal anatomy, but abnormal physiology, would be treated with an even less invasive type procedure, specifically, an endoluminal approach or an incisionless approach for reconstruction or reinforcement of the gastroesophageal (GE) valve. Recently, multiple new modalities have been developed that can be performed with even less invasion than laparoscopy. These endoluminal approaches to the treatment for esophageal reflux disease have included radio-frequency energy application to the distal esophagus, the addition of bulking agents to the GE junction, and endoluminal mechanical reconstruction or plication of the GE junction. Currently, only radio-frequency application to the GE junction and mechanical reconstruction of the lower esophageal sphincter mechanism are available techniques using endoluminal techniques.


Patient Assessment

Patients who present with symptomatic GERD should be evaluated with upper endoscopy. This allows an evaluation of the mucosal lining of the esophagus and stomach and can provide some evidence of mechanical integrity as well. The esophagus should be specifically inspected for ulcerations or the presence of Barrett’s esophagus. A retroflexed image of the GE junction should be included as well, in order to assess the competency of the lower esophageal sphincter and look for evidence of hiatal hernia. Complete examination of the stomach and duodenum is important to rule out other disease processes. The evaluation of esophageal physiology is important as well. Some authors have suggested that a video barium esophagogram can provide adequate information about motility and esophageal emptying. Other authors have recommended that formal esophageal manometry is necessary for all patients who are undergoing consideration for an antireflux procedure. An objective evaluation of GERD disease is important as well. While classic symptoms and/or the presence of Barrett’s esophagus may be indicative, many patients will continue to have symptoms without objective evidence. Most patients should undergo some objective evaluation for reflux. This is most commonly done with an implantable pH meter placed 4 to 6 cm above the Z-line in the distal esophagus at the time of endoscopy. The probe can provide 48 hours of data to determine the objective amount of acid reflux. Alternatively, a 24-hour nasogastric catheter can be left in place, and in addition to measuring acid reflux, the impedance catheter with appropriate computer analysis can allow a good indication of the amount of aboral transit of nonacid reflux. Symptom correlation can also be obtained to give the treating physician adequate objective information about the degree of reflux.

Patients with objective evidence of GERD, acid or nonacid, those who are poorly controlled on medication or do not wish to take medication, or those who have significant extraesophageal manifestations will likely benefit from an antireflux procedure. In most situations, the selection of the appropriate procedure is based on the patient’s individual clinical characteristics, and anatomic derangements and physician expertise. The current state of endoluminal therapy does not allow major reconstruction of disordered anatomy. Patients with hiatal hernias that are greater than 2 or 3 cm in size, have strictures or severe esophagitis, or are morbidly obese are not good candidates for any endoluminal therapy at the current time. The use of these procedures has not been well described for Barrett’s esophagus. Endoluminal treatment of GERD remains a new technology and early results demonstrate promising data; however, long-term objective data are lacking for these recent advances in the control of GERD.


Endoluminal Treatment Alternatives for Gerd Disease

Radio-frequency energy application to the distal esophageal sphincter for reflux disease was launched with a product called Stretta (Curon Medical Corporation, Fremont, CA). This device was approved by the Food and Drug Administration (FDA) in the year 2000 after several years of development. Radio-frequency energy has been used for a variety of treatments since the 1920s. The Stretta catheter is a disposable catheter that has a balloon tip associated with four separate electrodes that can be inserted into the esophageal wall after the balloon is inflated to efface the esophageal wall. Radio-frequency energy is delivered to the tip of the electrode with computer monitoring of the temperatures of both the mucosa and the tip of the electrode. The procedure is designed to be an outpatient endoscopic procedure with intravenous sedation without the need for general anesthesia. Total time for application of the procedure is approximately 45 minutes.

A variety of human data has been reported, including 119 patients for whom the initial reports were reported. With a 12-month follow-up, heartburn score, GERD score, and symptom score were all significantly decreased. The percentage of time that the pH was below 4 also significantly decreased from 10.1 to 6.4. Data continued to be collected in a randomized double-blind sham control multicenter clinical trial, published by Douglas Corley et al., that demonstrated significant differences in symptom scores and heartburn scores. Initially, 24-hour ambulatory pH demonstrated no significant difference. At 6 months, however, patients underwent a crossover, and at 12 months both groups had significant reduction in acid exposure by pH probe compared with their preprocedure baseline. Wolfsen reported on his
registry of 538 patients from 33 centers. Symptom scores and lifestyle scores were significantly better, medication usage was less, and many patients were noted to have better results after 1 year compared with less than 1 year. The Ohio State University reported on their first 50 patients with an average 10-month follow-up; this particular series was significant for having 18 patients with a body mass index (BMI) >30 and 10 patients who had previous antireflux surgery. In this series, all of the patients except one were consciously sedated. There were no complications and no patients required admission; five of the patients progressed to surgical intervention because of failure to control symptoms. In all patients the overall heartburn score was decreased from 3.19 to 1.74. The overall symptom satisfaction score and GERD-specific quality of life scores were significantly improved as well. Long-term follow-up of this cohort published in 2007 demonstrated good relief of symptoms in over 50% of patients with initial treatment. Not all published data agreed with these results; at Ohio State most patients went on to have other procedures to treat their reflux symptoms. One recent study from Europe evaluated pH data at 6-month follow-up. Total acid exposure time was significantly decreased (16.7 to 8.8% (P .001)) and medication usage decreased in 75% of patients. Another series has demonstrated very good long-term results; Noar and Lofti-Emaran followed 109 patients, of whom 96 were available for 48-month follow-up. Symptom scoring and disease-specific quality of life measures were all significantly improved early on and stayed that way over the study period. Additionally, daily proton pump inhibitors (PPI) use was significantly decreased. Other centers are following cohorts for further long-term data and pH data.

In December 2006, Curon Medical filed for bankruptcy and ceased operations. The technology was sold and acquired by Vision Science, Inc., and subsequently licensed to Mederi Therapeutics, Inc. (Greenwich, CT, USA). The Stretta catheter is currently available for use in the United States.

In summary, the Stretta procedure is a safe and somewhat reliable method to treat esophageal reflux with a low frequency of complications. The mechanism of action remains unclear. Mixed results for 24-hour pH data following the procedure remain confusing. While many patients do have adequate symptom relief, further long-term follow-up is needed to define the length or the duration of symptom relief in these patients and the amount of acid control that is offered to the lower esophageal sphincter. This endoluminal treatment of GERD may play a role in the management of patients with GERD and especially those with recurrent or mild disease.


Bulking Agents

Bolstering the lower esophageal sphincter by injection of inert material was an idea first described by O’Connor in the late 1980s. In their trial, 10 patients underwent injection of an inert material into the distal esophageal wall, “bolstering” the GE junction and subsequently reducing symptoms. The basic assumption was that by creating a physical and mechanical barrier at the lower esophageal sphincter, reflux will be reduced in these patients. In April 2003, the U.S. FDA approved the Enteryx Procedure Kit (Boston Scientific, Boston, MA) for the treatment of GERD symptoms in patients responding to and requiring daily pharmacological therapy with PPI medications. This was an ethylene vinyl alcohol copolymer solution that could be injected into the intrasphincteric space under fluoroscopic guidance using endoscopy. The initial multicenter trial evaluated 85 patients who were followed for 6 months. Proton pump inhibitor use was eliminated in 75% of the patients and another 10% of the patients had a reduced dose. Symptom scores and heartburn-related quality of life scores improved significantly. Acid exposure also decreased significantly, from 9.5% to 6.7%, in the initial follow-up. During this trial, published by Johnson et al., there were no clinically adverse events reported. However, after release of Enteryx into the U.S. market, multiple complications were reported, specifically aorta enteric fistula and embolization of the product during injection into the aorta. On October 14, 2005, the FDA released a recall of Enteryx procedure kits and Enteryx injection and it was voluntarily withdrawn from the market shortly thereafter. It is currently not available in the United States.

A proprietary injectable agent containing carbon-coated beads have been trialed as a bulking agent as well. The product (Durasphere, Carbon Medical Technologies, St. Paul, Minnesota, USA) is FDA approved for use as an injectable to help with urinary incontinence. In one trial 10 patients were treated by submucosal injection near the GE junction. Four of nine patients had normalized pH. Further studies are required and this technique has not gained widespread use.

The Gatekeeper system (Endonetics, San Diego, CA) is a hydrogel prosthesis that expands about 90% after exposure to water. It was designed to be applied with a device into the submucosal space. After approximately 6 hours, the prosthetic expanded to almost 90% of its final size, creating increased bulk in a submucosal location at the distal esophageal sphincter. This device underwent clinical trials in Europe and a multicenter study has been published by Fockens, in which 67 patients were treated using 77 different procedures. Acid exposure was reduced significantly; 53 of the 67 patients were off PPIs and symptom scores were reduced significantly as well. During this trial two adverse events were reported and one patient had the prosthetics removed. This device has not been submitted for FDA approval in the United States and is currently not available.


Endoscopic Plication

A variety of devices have been developed to create a mechanical barrier at the GE junction using natural tissue. Endocinch (Bard Corp., Murray Hill, NJ) was the first FDA-approved endoscopic suturing device utilized for reflux and perforations of the upper gastrointestinal (GI) tract. This was performed as an outpatient endoscopic procedure in conjunction with an overtube. The device is placed at the end of an endoscope and the GE junction can then be plicated vertically or circumferentially. While the procedure does require advanced endoscopic and suturing skills and about 1 hour of procedure time, the initial results were promising. One multicenter trial of 64 patients showed a symptom reduction in about 70% of patients. Subsequent human data have not been as promising; in one study, no evidence of plication was seen at endoscopy in the follow-up period and subsequent recurrence of symptoms at relatively short intervals following initial therapy. The Endocinch remains available in the United States, but its use and reported data have been somewhat limited. Other similar suturing devices are available and seem to be of similar usefulness.

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Aug 2, 2016 | Posted by in GENERAL SURGERY | Comments Off on Gastroesophageal Reflux Disease: Endoluminal Approaches
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