Lower esophageal electrical stimulation therapy targets GERD

Electrical stimulation of the lower esophageal sphincter using an implanted device shows promise for the treatment of gastroesophageal reflux, according to findings from three recent studies.

In one open-label pilot extension study, 77% of 23 patients treated with EndoStim’s Lower Esophageal Sphincter (LES) stimulation system reported normalization of (or at least a 50% reduction in) distal esophageal acid exposure at 12 months’ follow-up, Dr. Edy Soffer reported in October at the annual meeting of the American College of Gastroenterology.

Courtesy Dr. Mark I. van Berge Henegouwen

The patients also experienced significant improvement in their median GERD-Health Related Quality of Life (GERD-HRQL) score while implanted with the LES stimulation system (LES-EST), compared with their score while on proton pump inhibitor (PPI) therapy (increase of 9 vs. 2 points) and while off PPI therapy (increase of 23.5 vs. 2), said Dr. Soffer, professor of clinical medicine and director of the GI motility program at the University of Southern California, Los Angeles.

All but one patient reported cessation of regular PPI use, and no implantation- or stimulation-related unanticipated adverse events or "untoward sensation" due to stimulation occurred during follow-up; nor was swallowing function as assessed by manometry affected.

Patients included in the study were GERD patients with a mean age of 53 years who were at least partially responsive to PPI therapy, and who had off-PPI GERD-HRQL scores of at least 20, as well as hiatal hernia.

The findings indicate that LES-EST, which uses low-energy electrical pulses to strengthen a weak or dysfunctional lower esophageal sphincter, is safe and effective for long-term use, he said.

In an interview, Dr. Soffer said that the findings have held up at 18 months of follow-up.

"The results are comparable to those observed at 12 months with regard to control of symptoms, and with near elimination of the use of PPIs," he said, noting that the safety profile remains excellent, with no new adverse event reported beyond those seen at 12 months’ follow-up.

Physiological studies such as esophageal pH will be conducted at 24 months, he said.

In a related study presented in a poster at the meeting, Michael Crowell, Ph.D., looked more closely at the effects of LES-EST on both distal and proximal esophageal acid exposure in a post hoc analysis.

In 19 patients with a median age of 54 years, LES-EST was associated with normalization of total and upright proximal esophageal acid exposure, which improved from 0.4% and 0.6%, respectively, at baseline to 0% at 12 months’ follow-up. Supine esophageal acid exposure was unchanged from 0% at baseline, said Dr. Crowell of the Mayo Clinic, Scottsdale, Ariz.

This was true even among seven patients with abnormal proximal esophageal pH, whose total, upright, and supine proximal esophageal acid exposure values at baseline were 1.7%, 2.9%, and 0.3%, respectively. Distal esophageal pH improved from 10.2% to 3.6% for the entire cohort, and from 9.3% to 3.4% in those seven patients.

Patients in this study had GERD that was at least partially responsive to PPIs, a hiatal hernia of less than 3 cm, and esophagitis of less than Los Angeles Classification grade D. Electrical stimulation was administered for 220 microseconds at 20 Hz and 5-8 mA in 6-12 30-minute sessions starting on day 1 after implantation.

No gastrointestinal side effects occurred in the patients, nor were there any device- or procedure-related adverse events.

LES-EST may be effective in treating proximal GERD, Dr. Crowell concluded.

In an interview, he added that the findings are important, particularly for the one-third of patients who remain symptomatic on PPIs.

"LES dysfunction is the root cause of GERD. Medications such as PPIs block stomach acid production, but do not address the pathophysiology of GERD. Hence, more than a third of patients continue to suffer from symptoms despite maximal medical therapy," he said.

Additionally, there are significant safety concerns with long-term acid suppression, he noted.

LES-EST, on the other hand, addresses the root cause of GERD by improving LES pressure and function, thereby restoring the LES physiology and its barrier function, preventing reflux of gastric acid into the esophagus.

"LES stimulation does not affect normal LES relaxation, allowing for the patient to swallow normally, and has no side effects," he said.

In a third, unrelated study also reported in a poster at the meeting, LES-EST was similarly effective.

Of 11 patients treated with EndoStim’s LES stimulation system as part of an international multicenter study, 10 were able to discontinue PPI therapy at 3-6 months of follow-up, according to Dr. Arjan J. Bredenoord of Academic Medical Center Utrecht, Rotterdam.

Those 10 patients experienced significant improvements in median GERD-HRQL scores from 32 (off PPIs) and 22 (on PPIs) to 9 (on LES-EST) at 3 months, and the scores remained stable at 9 points in 3 patients who were followed for 6 months.

Median esophageal acid exposure improved from 11.8% at baseline to 7.8% at 3 months and 7.3% at 6 months, Dr. Bredenoord said.

The remaining patient suffered a small bowl trocar perforation during implantation of the device and underwent successful repair. An additional 13 adverse events, including 1 serious adverse event, were reported in 4 patients. Nine of these were related to the device or procedure, including seven complaints of pain at the implant site and one case of postoperative nausea.

The treatment was safe, with no GI or cardiac side effects, Dr. Bredenoord concluded, noting that long-term safety and efficacy results in a larger group of patients are currently being analyzed.

In an interview, Dr. Bredenoord noted that the findings are among the first in patients outside South America, where the earliest trials of the EndoStim LES stimulation system were conducted.

"The data confirm the favorable outcome of the patients in Chile, and show that both symptoms and reflux are reduced in European patients as well," he said.

However, the experience remains limited, and additional study comparing the device with other treatments and/or with placebo is needed, as are longer-term outcomes data.

"I think that although these results suggest this is a promising treatment, it would be best to treat patients only in trials" at this point, he said. Because trial participants have been carefully selected, it remains unclear whether this treatment is suitable for the entire GERD population, he added.

Dr. Soffer agreed, and said that if the results are reproduced in additional studies with a larger number of patients, the intervention will provide an alternative therapy for GERD patients who are not satisfied with PPIs or who have concerns about side effects and the chronic use of treatment, and who also have concerns about the established surgical treatment for GERD.

"The importance of this intervention is in providing a bridge between the currently established drug therapy for GERD [PPIs] and the established surgical therapy [fundoplication]. While PPIs are effective in a substantial number of GERD patients, they do not correct the underlying pathophysiology of GERD, resulting in a substantial number of patients who remain symptomatic in spite of therapy," he said.

These patients can be offered fundoplication, which is effective in expert hands, but the surgery has side effects and is performed less and less often, he added.

"Consequently, there is a search for a bridge intervention, endoscopic or surgical, for the treatment of GERD," he said.

LES-EST appears to have the potential to be such a bridge intervention.

"The procedure is simple and nondisruptive, and addresses pathophysiology. The safety profile thus far is excellent, and the effect on esophageal acid exposure, symptoms, and PPI use is sustained over a period of 12-18 moths. Furthermore, the treatment can be optimized to individual needs by adjusting delivery of stimulation to coincide with periods when symptoms and acid reflux are detected," he said.

All three of these studies presented at the meeting were supported by EndoStim BV. Dr. Soffer disclosed that he has stockholder/ownership interest in the company. Dr. Crowell disclosed that he has served as a consultant to the company. Dr. Bredenoord reported receiving grant and/or research support from the company.

Electrical stimulation of the lower esophageal sphincter using an implanted device shows promise for the treatment of gastroesophageal reflux, according to findings from three recent studies.

In one open-label pilot extension study, 77% of 23 patients treated with EndoStim’s Lower Esophageal Sphincter (LES) stimulation system reported normalization of (or at least a 50% reduction in) distal esophageal acid exposure at 12 months’ follow-up, Dr. Edy Soffer reported in October at the annual meeting of the American College of Gastroenterology.

Courtesy Dr. Mark I. van Berge Henegouwen

The patients also experienced significant improvement in their median GERD-Health Related Quality of Life (GERD-HRQL) score while implanted with the LES stimulation system (LES-EST), compared with their score while on proton pump inhibitor (PPI) therapy (increase of 9 vs. 2 points) and while off PPI therapy (increase of 23.5 vs. 2), said Dr. Soffer, professor of clinical medicine and director of the GI motility program at the University of Southern California, Los Angeles.

All but one patient reported cessation of regular PPI use, and no implantation- or stimulation-related unanticipated adverse events or "untoward sensation" due to stimulation occurred during follow-up; nor was swallowing function as assessed by manometry affected.

Patients included in the study were GERD patients with a mean age of 53 years who were at least partially responsive to PPI therapy, and who had off-PPI GERD-HRQL scores of at least 20, as well as hiatal hernia.

The findings indicate that LES-EST, which uses low-energy electrical pulses to strengthen a weak or dysfunctional lower esophageal sphincter, is safe and effective for long-term use, he said.

In an interview, Dr. Soffer said that the findings have held up at 18 months of follow-up.

"The results are comparable to those observed at 12 months with regard to control of symptoms, and with near elimination of the use of PPIs," he said, noting that the safety profile remains excellent, with no new adverse event reported beyond those seen at 12 months’ follow-up.

Physiological studies such as esophageal pH will be conducted at 24 months, he said.

In a related study presented in a poster at the meeting, Michael Crowell, Ph.D., looked more closely at the effects of LES-EST on both distal and proximal esophageal acid exposure in a post hoc analysis.

In 19 patients with a median age of 54 years, LES-EST was associated with normalization of total and upright proximal esophageal acid exposure, which improved from 0.4% and 0.6%, respectively, at baseline to 0% at 12 months’ follow-up. Supine esophageal acid exposure was unchanged from 0% at baseline, said Dr. Crowell of the Mayo Clinic, Scottsdale, Ariz.

This was true even among seven patients with abnormal proximal esophageal pH, whose total, upright, and supine proximal esophageal acid exposure values at baseline were 1.7%, 2.9%, and 0.3%, respectively. Distal esophageal pH improved from 10.2% to 3.6% for the entire cohort, and from 9.3% to 3.4% in those seven patients.

Patients in this study had GERD that was at least partially responsive to PPIs, a hiatal hernia of less than 3 cm, and esophagitis of less than Los Angeles Classification grade D. Electrical stimulation was administered for 220 microseconds at 20 Hz and 5-8 mA in 6-12 30-minute sessions starting on day 1 after implantation.

No gastrointestinal side effects occurred in the patients, nor were there any device- or procedure-related adverse events.

LES-EST may be effective in treating proximal GERD, Dr. Crowell concluded.

In an interview, he added that the findings are important, particularly for the one-third of patients who remain symptomatic on PPIs.

"LES dysfunction is the root cause of GERD. Medications such as PPIs block stomach acid production, but do not address the pathophysiology of GERD. Hence, more than a third of patients continue to suffer from symptoms despite maximal medical therapy," he said.

Additionally, there are significant safety concerns with long-term acid suppression, he noted.

LES-EST, on the other hand, addresses the root cause of GERD by improving LES pressure and function, thereby restoring the LES physiology and its barrier function, preventing reflux of gastric acid into the esophagus.

"LES stimulation does not affect normal LES relaxation, allowing for the patient to swallow normally, and has no side effects," he said.

In a third, unrelated study also reported in a poster at the meeting, LES-EST was similarly effective.

Of 11 patients treated with EndoStim’s LES stimulation system as part of an international multicenter study, 10 were able to discontinue PPI therapy at 3-6 months of follow-up, according to Dr. Arjan J. Bredenoord of Academic Medical Center Utrecht, Rotterdam.

Those 10 patients experienced significant improvements in median GERD-HRQL scores from 32 (off PPIs) and 22 (on PPIs) to 9 (on LES-EST) at 3 months, and the scores remained stable at 9 points in 3 patients who were followed for 6 months.

Median esophageal acid exposure improved from 11.8% at baseline to 7.8% at 3 months and 7.3% at 6 months, Dr. Bredenoord said.

The remaining patient suffered a small bowl trocar perforation during implantation of the device and underwent successful repair. An additional 13 adverse events, including 1 serious adverse event, were reported in 4 patients. Nine of these were related to the device or procedure, including seven complaints of pain at the implant site and one case of postoperative nausea.

The treatment was safe, with no GI or cardiac side effects, Dr. Bredenoord concluded, noting that long-term safety and efficacy results in a larger group of patients are currently being analyzed.

In an interview, Dr. Bredenoord noted that the findings are among the first in patients outside South America, where the earliest trials of the EndoStim LES stimulation system were conducted.

"The data confirm the favorable outcome of the patients in Chile, and show that both symptoms and reflux are reduced in European patients as well," he said.

However, the experience remains limited, and additional study comparing the device with other treatments and/or with placebo is needed, as are longer-term outcomes data.

"I think that although these results suggest this is a promising treatment, it would be best to treat patients only in trials" at this point, he said. Because trial participants have been carefully selected, it remains unclear whether this treatment is suitable for the entire GERD population, he added.

Dr. Soffer agreed, and said that if the results are reproduced in additional studies with a larger number of patients, the intervention will provide an alternative therapy for GERD patients who are not satisfied with PPIs or who have concerns about side effects and the chronic use of treatment, and who also have concerns about the established surgical treatment for GERD.

"The importance of this intervention is in providing a bridge between the currently established drug therapy for GERD [PPIs] and the established surgical therapy [fundoplication]. While PPIs are effective in a substantial number of GERD patients, they do not correct the underlying pathophysiology of GERD, resulting in a substantial number of patients who remain symptomatic in spite of therapy," he said.

These patients can be offered fundoplication, which is effective in expert hands, but the surgery has side effects and is performed less and less often, he added.

"Consequently, there is a search for a bridge intervention, endoscopic or surgical, for the treatment of GERD," he said.

LES-EST appears to have the potential to be such a bridge intervention.

"The procedure is simple and nondisruptive, and addresses pathophysiology. The safety profile thus far is excellent, and the effect on esophageal acid exposure, symptoms, and PPI use is sustained over a period of 12-18 moths. Furthermore, the treatment can be optimized to individual needs by adjusting delivery of stimulation to coincide with periods when symptoms and acid reflux are detected," he said.

All three of these studies presented at the meeting were supported by EndoStim BV. Dr. Soffer disclosed that he has stockholder/ownership interest in the company. Dr. Crowell disclosed that he has served as a consultant to the company. Dr. Bredenoord reported receiving grant and/or research support from the company.

Electrical stimulation of the lower esophageal sphincter using an implanted device shows promise for the treatment of gastroesophageal reflux, according to findings from three recent studies.

In one open-label pilot extension study, 77% of 23 patients treated with EndoStim’s Lower Esophageal Sphincter (LES) stimulation system reported normalization of (or at least a 50% reduction in) distal esophageal acid exposure at 12 months’ follow-up, Dr. Edy Soffer reported in October at the annual meeting of the American College of Gastroenterology.

Courtesy Dr. Mark I. van Berge Henegouwen

The patients also experienced significant improvement in their median GERD-Health Related Quality of Life (GERD-HRQL) score while implanted with the LES stimulation system (LES-EST), compared with their score while on proton pump inhibitor (PPI) therapy (increase of 9 vs. 2 points) and while off PPI therapy (increase of 23.5 vs. 2), said Dr. Soffer, professor of clinical medicine and director of the GI motility program at the University of Southern California, Los Angeles.

All but one patient reported cessation of regular PPI use, and no implantation- or stimulation-related unanticipated adverse events or "untoward sensation" due to stimulation occurred during follow-up; nor was swallowing function as assessed by manometry affected.

Patients included in the study were GERD patients with a mean age of 53 years who were at least partially responsive to PPI therapy, and who had off-PPI GERD-HRQL scores of at least 20, as well as hiatal hernia.

The findings indicate that LES-EST, which uses low-energy electrical pulses to strengthen a weak or dysfunctional lower esophageal sphincter, is safe and effective for long-term use, he said.

In an interview, Dr. Soffer said that the findings have held up at 18 months of follow-up.

"The results are comparable to those observed at 12 months with regard to control of symptoms, and with near elimination of the use of PPIs," he said, noting that the safety profile remains excellent, with no new adverse event reported beyond those seen at 12 months’ follow-up.

Physiological studies such as esophageal pH will be conducted at 24 months, he said.

In a related study presented in a poster at the meeting, Michael Crowell, Ph.D., looked more closely at the effects of LES-EST on both distal and proximal esophageal acid exposure in a post hoc analysis.

In 19 patients with a median age of 54 years, LES-EST was associated with normalization of total and upright proximal esophageal acid exposure, which improved from 0.4% and 0.6%, respectively, at baseline to 0% at 12 months’ follow-up. Supine esophageal acid exposure was unchanged from 0% at baseline, said Dr. Crowell of the Mayo Clinic, Scottsdale, Ariz.

This was true even among seven patients with abnormal proximal esophageal pH, whose total, upright, and supine proximal esophageal acid exposure values at baseline were 1.7%, 2.9%, and 0.3%, respectively. Distal esophageal pH improved from 10.2% to 3.6% for the entire cohort, and from 9.3% to 3.4% in those seven patients.

Patients in this study had GERD that was at least partially responsive to PPIs, a hiatal hernia of less than 3 cm, and esophagitis of less than Los Angeles Classification grade D. Electrical stimulation was administered for 220 microseconds at 20 Hz and 5-8 mA in 6-12 30-minute sessions starting on day 1 after implantation.

No gastrointestinal side effects occurred in the patients, nor were there any device- or procedure-related adverse events.

LES-EST may be effective in treating proximal GERD, Dr. Crowell concluded.

In an interview, he added that the findings are important, particularly for the one-third of patients who remain symptomatic on PPIs.

"LES dysfunction is the root cause of GERD. Medications such as PPIs block stomach acid production, but do not address the pathophysiology of GERD. Hence, more than a third of patients continue to suffer from symptoms despite maximal medical therapy," he said.

Additionally, there are significant safety concerns with long-term acid suppression, he noted.

LES-EST, on the other hand, addresses the root cause of GERD by improving LES pressure and function, thereby restoring the LES physiology and its barrier function, preventing reflux of gastric acid into the esophagus.

"LES stimulation does not affect normal LES relaxation, allowing for the patient to swallow normally, and has no side effects," he said.

In a third, unrelated study also reported in a poster at the meeting, LES-EST was similarly effective.

Of 11 patients treated with EndoStim’s LES stimulation system as part of an international multicenter study, 10 were able to discontinue PPI therapy at 3-6 months of follow-up, according to Dr. Arjan J. Bredenoord of Academic Medical Center Utrecht, Rotterdam.

Those 10 patients experienced significant improvements in median GERD-HRQL scores from 32 (off PPIs) and 22 (on PPIs) to 9 (on LES-EST) at 3 months, and the scores remained stable at 9 points in 3 patients who were followed for 6 months.

Median esophageal acid exposure improved from 11.8% at baseline to 7.8% at 3 months and 7.3% at 6 months, Dr. Bredenoord said.

The remaining patient suffered a small bowl trocar perforation during implantation of the device and underwent successful repair. An additional 13 adverse events, including 1 serious adverse event, were reported in 4 patients. Nine of these were related to the device or procedure, including seven complaints of pain at the implant site and one case of postoperative nausea.

The treatment was safe, with no GI or cardiac side effects, Dr. Bredenoord concluded, noting that long-term safety and efficacy results in a larger group of patients are currently being analyzed.

In an interview, Dr. Bredenoord noted that the findings are among the first in patients outside South America, where the earliest trials of the EndoStim LES stimulation system were conducted.

"The data confirm the favorable outcome of the patients in Chile, and show that both symptoms and reflux are reduced in European patients as well," he said.

However, the experience remains limited, and additional study comparing the device with other treatments and/or with placebo is needed, as are longer-term outcomes data.

"I think that although these results suggest this is a promising treatment, it would be best to treat patients only in trials" at this point, he said. Because trial participants have been carefully selected, it remains unclear whether this treatment is suitable for the entire GERD population, he added.

Dr. Soffer agreed, and said that if the results are reproduced in additional studies with a larger number of patients, the intervention will provide an alternative therapy for GERD patients who are not satisfied with PPIs or who have concerns about side effects and the chronic use of treatment, and who also have concerns about the established surgical treatment for GERD.

"The importance of this intervention is in providing a bridge between the currently established drug therapy for GERD [PPIs] and the established surgical therapy [fundoplication]. While PPIs are effective in a substantial number of GERD patients, they do not correct the underlying pathophysiology of GERD, resulting in a substantial number of patients who remain symptomatic in spite of therapy," he said.

These patients can be offered fundoplication, which is effective in expert hands, but the surgery has side effects and is performed less and less often, he added.

"Consequently, there is a search for a bridge intervention, endoscopic or surgical, for the treatment of GERD," he said.

LES-EST appears to have the potential to be such a bridge intervention.

"The procedure is simple and nondisruptive, and addresses pathophysiology. The safety profile thus far is excellent, and the effect on esophageal acid exposure, symptoms, and PPI use is sustained over a period of 12-18 moths. Furthermore, the treatment can be optimized to individual needs by adjusting delivery of stimulation to coincide with periods when symptoms and acid reflux are detected," he said.

All three of these studies presented at the meeting were supported by EndoStim BV. Dr. Soffer disclosed that he has stockholder/ownership interest in the company. Dr. Crowell disclosed that he has served as a consultant to the company. Dr. Bredenoord reported receiving grant and/or research support from the company.