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Regarding “Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease”
ARTICLE IN PRESS
Letter to the Editors Letter to the editor regarding the article: Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease
To the Editors: I read with interest the report by Rodriquez et al1 and the editorial by Attwood2 on the electrical stimulation of the lower esophageal sphincter (LES) for the therapy of gastroesophageal reflux disease (GERD). Attwood acknowledges the ongoing existence of a gap in our therapeutic armamentarium for the treatment of GERD and explains the unique benefits of electrical LES modulation as a solution to the problem. I was impressed by the 2-year sustained decrease in esophageal acid exposure obtained with the device and concur with Dr Attwood’s comment that ‘‘there is no other therapy that has this magnitude of effect and lack of side effects.’’ I agree with Attwood that a future sham-control trial would further validate the existing clinical data. Indeed, the programmability of the system lends itself to such a trial design. His reason for a sham-control study is the susceptibility of an open-label study to a placebo effect when subjective variables are assessed. In contrast, the objective measurement of esophageal acid exposure is less prone to such bias. The placebo effect of a sham decrease of esophageal acid exposure is small or nonexistent.3,4 Thus, the sustained decrease of acid exposure during a 2-year period as documented in the article and a similar effect reported by Siersema et al5 in a multicenter trial provides strong support that electrical LES modulation has a true effect on the decrease of esophageal acid exposure. These observations provide confidence for the current clinical use of this technology in selected GERD patients with documented increased esophageal acid exposure, normal hiatal anatomy, and a partial response to proton pump inhibitor therapy. For sure subsequent, randomized-controlled trial against proton pump inhibitors will be needed for wide acceptance of this therapy. In such a trial, care should be taken to minimize the difference between the study groups by stratifying or excluding factors known to affect the degree of esophageal acid exposure, such as a hiatal hernia, a structurally defective LES, and/or Barrett’s esophagus, because electrical modulation of the LES is designed to augment the
existing LES rather than reconstructing a new sphincter as the Nissen does. Attwood also suggested a randomized controlled study comparing electronic LES modulation with the standard of practice, ie, a surgical fundoplication. This is a much harder trial to conduct. Patients with early disease may not consent to such a trial, because they fear a fundoplication may induce symptoms more severe than their current symptoms. This type of study would pose a challenge to randomization. Rather, I would propose using the tool of propensity matching. In such a trial, patients from an existing fundoplication data base are matched in regard to risk factors and measurements of disease severity to patients who had electronic LES modulation. Such a design can bring a study closer to a randomized control study without the necessity of being one. Tom R. DeMeester, MD Professor of Surgery, Emeritus Keck School of Medicine University of Southern California San Marino, CA E-mail: [email protected]
References 1. Rodriguez L, Rodriquez P, Gomez B, Ayala J, Oxenberg D, Perez-Castilla A, et al. Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease. Surgery 2015;157:556-67. 2. Attwood SE. Electrical stimulation for gastroesophageal reflux disease: formal randomized clinical trials are needed. Surgery 2015;157:568-9. 3. Rothstein RI. Endoscopic therapy of gastroesphageal reflux disease: outcomes of the randomized-controlled trials done to date. J Clin Gastroenterol 2008;42:594-602. 4. Hunter JG, Kahrilas PJ, Bell RC, Wilson EB, Trad KS, Dolan JP, et al. Efficacy of transoral fundoplication vs. omeprazole for treatment of regurgitation in a randomized controlled trial. Gastroenterology 2015;148:324-33. 5. Siersema PD, Bredenoord AJ, Conchillo JM, Ruurda JP, Bouvy N, van Berge Henegouwen MI, et al. Electrical stimulation therapy (EST) of the lower esophageal sphincter (LES)---an effective therapy for refractory GERD---Interim results of an international multicenter trial. Gastroenterology 2014;146:S-167. http://dx.doi.org/10.1016/j.surg.2015.03.011
SURGERY 1
Letter to the Editors Letter to the editor regarding the article: Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease
To the Editors: I read with interest the report by Rodriquez et al1 and the editorial by Attwood2 on the electrical stimulation of the lower esophageal sphincter (LES) for the therapy of gastroesophageal reflux disease (GERD). Attwood acknowledges the ongoing existence of a gap in our therapeutic armamentarium for the treatment of GERD and explains the unique benefits of electrical LES modulation as a solution to the problem. I was impressed by the 2-year sustained decrease in esophageal acid exposure obtained with the device and concur with Dr Attwood’s comment that ‘‘there is no other therapy that has this magnitude of effect and lack of side effects.’’ I agree with Attwood that a future sham-control trial would further validate the existing clinical data. Indeed, the programmability of the system lends itself to such a trial design. His reason for a sham-control study is the susceptibility of an open-label study to a placebo effect when subjective variables are assessed. In contrast, the objective measurement of esophageal acid exposure is less prone to such bias. The placebo effect of a sham decrease of esophageal acid exposure is small or nonexistent.3,4 Thus, the sustained decrease of acid exposure during a 2-year period as documented in the article and a similar effect reported by Siersema et al5 in a multicenter trial provides strong support that electrical LES modulation has a true effect on the decrease of esophageal acid exposure. These observations provide confidence for the current clinical use of this technology in selected GERD patients with documented increased esophageal acid exposure, normal hiatal anatomy, and a partial response to proton pump inhibitor therapy. For sure subsequent, randomized-controlled trial against proton pump inhibitors will be needed for wide acceptance of this therapy. In such a trial, care should be taken to minimize the difference between the study groups by stratifying or excluding factors known to affect the degree of esophageal acid exposure, such as a hiatal hernia, a structurally defective LES, and/or Barrett’s esophagus, because electrical modulation of the LES is designed to augment the
existing LES rather than reconstructing a new sphincter as the Nissen does. Attwood also suggested a randomized controlled study comparing electronic LES modulation with the standard of practice, ie, a surgical fundoplication. This is a much harder trial to conduct. Patients with early disease may not consent to such a trial, because they fear a fundoplication may induce symptoms more severe than their current symptoms. This type of study would pose a challenge to randomization. Rather, I would propose using the tool of propensity matching. In such a trial, patients from an existing fundoplication data base are matched in regard to risk factors and measurements of disease severity to patients who had electronic LES modulation. Such a design can bring a study closer to a randomized control study without the necessity of being one. Tom R. DeMeester, MD Professor of Surgery, Emeritus Keck School of Medicine University of Southern California San Marino, CA E-mail: [email protected]
References 1. Rodriguez L, Rodriquez P, Gomez B, Ayala J, Oxenberg D, Perez-Castilla A, et al. Two-year results of intermittent electrical stimulation of the lower esophageal sphincter treatment of gastroesophageal reflux disease. Surgery 2015;157:556-67. 2. Attwood SE. Electrical stimulation for gastroesophageal reflux disease: formal randomized clinical trials are needed. Surgery 2015;157:568-9. 3. Rothstein RI. Endoscopic therapy of gastroesphageal reflux disease: outcomes of the randomized-controlled trials done to date. J Clin Gastroenterol 2008;42:594-602. 4. Hunter JG, Kahrilas PJ, Bell RC, Wilson EB, Trad KS, Dolan JP, et al. Efficacy of transoral fundoplication vs. omeprazole for treatment of regurgitation in a randomized controlled trial. Gastroenterology 2015;148:324-33. 5. Siersema PD, Bredenoord AJ, Conchillo JM, Ruurda JP, Bouvy N, van Berge Henegouwen MI, et al. Electrical stimulation therapy (EST) of the lower esophageal sphincter (LES)---an effective therapy for refractory GERD---Interim results of an international multicenter trial. Gastroenterology 2014;146:S-167. http://dx.doi.org/10.1016/j.surg.2015.03.011
SURGERY 1