Background and study aims: Implantable microstimulators (IMS) have been used in a variety of medical conditions. Selective stimulation to increase lower esophageal sphincter (LES) pressure may be useful in the control of gastroesophageal reflux disease. We evaluated on-demand stimulation of the LES with an endoscopically implanted microstimulator. Materials and methods: We performed acute experiments in three 30-kg dogs. After LES manometry, a 3.3 mm × 28 mm microstimulator (the Bion®) was implanted into the LES. Manometry was repeated with and without IMS stimulation to record the changes in LES pressure. Stimulation amplitude was varied from 3 mA to 10 mA, with a fixed frequency of 20 Hz and a pulse width of 200 µsec. Results: The mean LES pressures prior to IMS implantation in the three dogs were 13.0 mm Hg, 5.0 mm Hg, and 14.9 mm Hg. The mean pressures were not significantly changed by IMS placement. There were no documented changes in LES pressure when the amplitude of stimulation was less than 8 mA. After stimulation of the IMS at a setting of 10 mA in dogs 1 and 2 and at 8mA in dog 3, however, the resultant LES pressures were 62.1 mm Hg, 35.1 mm Hg, and 26.8 mm Hg respectively, more than three times higher than post-implantation baseline levels (P < 0.02). Conclusions: The LES pressure can be increased using an on-demand microstimulator. The implantation procedure is minimally invasive, represents a novel therapeutic approach to gastroesophageal reflux disease, and may have therapeutic potential for other gastrointestinal motility disorders.
References
-
1
Loeb G E, Zamin C J, Schulman J H, Troyk P R.
Injectable microstimulator for functional electrical stimulation.
Med Biol Eng Comput.
1991;
29
NS13-NS19
-
2
Baker L L, Palmer E, Waters R L, Chun S N.
Rehabilitation of the arm and hand following stroke: a clinical trial with Bions.
Proc IEEE EMBS.
2004;
2
4186-4188
-
3
Richmond F J, Loeb G E, Dupot A C. et al .
Clinical trials of Bions for therapeutic electrical stimulation.
Proc IEEE EMBS.
2001;
2
1301-1304
-
4
Carbunaru R, Whitehurst T, Jaax K. et al .
Rechargeable battery-powered Bion microstimulators for neuromodulation.
Proc IEEE EMBS.
2004;
2
4193-4196
-
5
Tran W H, Loeb G E, Richmond F J. et al .
First subject evaluated with simulated Bion treatment in posterior genioglossus to prevent obstructive sleep apnea.
Proc IEEE EMBS.
2004;
2
4287-4289
-
6
Baker L L, Waters R L, Winstein C. et al .
Neural interface and control proceedings. Clinical applications of Bion microstimulators.
Proc IEEE EMBS.
2005;
2
185-188
-
7
McCallum R W, Chen J D, Lin Z. et al .
Gastric pacing improves emptying and symptoms in patients with gastroparesis.
Gastroenterology.
1998;
114
456-461
-
8
Forster J, Sarosiek I, Delcore R. et al .
Gastric pacing is a new surgical treatment for gastroparesis.
Am J Surg.
2001;
182
676-681
-
9
Miller K, Hoeller E, Aigner F.
The implantable gastric stimulator for obesity: an update of the European experience in the LOSS (Laparoscopic Obesity Stimulation Survey) study.
Treat Endocrinol.
2006;
5
53-58
-
10
Cigaina V.
Long-term follow-up of gastric stimulation for obesity: the Mestre 8-year experience.
Obes Surg.
2004;
14
S14-S22
-
11
Bagger J P, Jensen B S, Johannsen G.
Long-term outcome of spinal cord electrical stimulation in patients with refractory chest pain.
Clin Cardiol.
1998;
21
286-288
-
12
Ganio E, Luc A R, Clerico G, Trompetto M.
Sacral nerve stimulation for treatment of fecal incontinence: a novel approach for intractable fecal incontinence.
Dis Colon Rectum.
2001;
44
619-629
-
13
DiMarco A F, Onders R P, Ignagni A R, Mortimer J T.
Phrenic nerve pacing via intramuscular diaphragm electrodes in tetraplegic subjects.
Chest.
2005;
127
671-678
-
14
Elefteriades J A, Quin J A, Hogan J F. et al .
Long-term follow-up of pacing of the conditioned diaphragm in quadriplegia.
Pacing Clin Electrophysiol.
2002;
25
897-906
-
15
Payne B R, Tiel R L, Payne M S, Fisch B.
Vagus nerve stimulation for chronic intractable hiccups.
J Neurosurg.
2005;
102
935-937
-
16
Finlayson S R, Laycock W S, Birkmeyer J D.
National trends in utilization and outcomes of antireflux surgery.
Surg Endosc.
2003;
17
864-867
-
17
Iqbal A, Awad Z, Simkins J. et al .
Repair of 104 failed anti-reflux operations.
Ann Surg.
2006;
244
42-51
-
18
Martin C, Dodds W, Liem H. et al .
Diaphragmatic contribution to gastroesophageal competence and reflux in dogs.
Am J Physiol.
1992;
263
G551-G557
-
19
Dent J, Holloway R H, Toouli J. et al .
Mechanisms of lower esophageal sphincter incompetence in patients with symptomatic gastroesophageal reflux.
Gut.
1988;
29
1020-1028
S. V. Kantsevoy, MD, PhD
Division of Gastroenterology, Johns Hopkins University
Room 423, 1830 E. Monument Street
Baltimore, Maryland 21205, USA
Fax: +1-410-614-7707
Email: svkan@jhmi.edu
