and researchers suggested patients with depleted Cajal cells who did not improve could have lost certain Cajal cells.
Thomas L. Abell, MD, from the department of medicine and division of gastroenterology, hepatology and nutrition at the University of Louisville (Ky.) and his colleagues recruited 23 patients with drug-refractory gastroparesis to undergo gastric electrical stimulation (GES) therapy for 12 months. Patients were white females with a mean age of 45.7 years. They performed a gastric-emptying test before therapy; the composite symptom scores were 23.89 plus or minus 34.10 for 4-hour gastric emptying in the group with interstitial cells of Cajal (ICC) less than 2.00 and a 22.62 plus or minus 25.51 in the group with ICC greater than or equal to 2.00.
“We believe neurostimulation might modify or augment the function of ICC cells. However, in patients with severe depletion, the ICC density might be too sparse to be augmented and hence contribute to suboptimal response to GES,” Dr. Abell and colleagues wrote in their study.
The GES system consisted of an “implanted pulse generator, two leads, and the stimulator programmer.” Patients used a trial GES system for 1-2 weeks, in which a “temporary lead is placed endoscopically through the nose and inserted into the gastric mucosa in the middle of the stomach.”
After the trial GES system, the researchers performed a gastric wall biopsy to determine ICC counts to divide the patients into two groups: those with less than 2 ICC and those with greater than or equal to 2 ICC (per high power field). Following the trial, a more permanent system was implanted and researchers analyzed results after 12 months with the Student t test, patient-reported symptom assessment, and Total Symptom Score (TSS) using a Likert scale.
After GES, 1-hour gastric emptying improved in the group with ICC greater than or equal to 2.00 from pretreatment (75.47 plus or minus 13.80) to posttreatment (57.97 plus or minus 21.34) with a mean between-group difference of 17.5% (95% confidence interval, 1.41-33.58; P = .035). Dr. Abell and colleagues noted a nonstatistically significant improvement in 2-hour (mean between-group difference, 8%) and 4-hour (4%) gastric emptying (P = .032). Compared with pretreatment, patients with an ICC count less that 2 showed no significant change at 1-hour (63.78 plus or minus 26.01 vs. 68.86 plus or minus 33.14; P = .646), 7% worsening at 2-hour (41.22 plus or minus 33.44 vs. 49.37 plus or minus 34.21; P = .343) and 7% worsening at 4-hour gastric emptying (23.89 plus or minus 34.10 vs. 30.82 plus or minus 30.82; P = .166).
Researchers found patients with “normal to moderate depletion of ICC counts” had a significantly higher change in serosal amplitude, with a mean amplitude change of 0.19 (P = .05). Patients with “severe depletion of ICC” showed no significant change in amplitude (mean amplitude change, 0.01; P = .79). Among patients with normal or moderate depletion of ICC, the pre-GES serosal frequency was 3.96 plus or minus 1.02 and the post-GES frequency was 3.83 plus or minus 1.36 (P = .79), while the patients with severe depletion of ICC had a pre-GES frequency of 4.67 plus or minus 1.57 and a post-GES frequency of 4.23 plus or minus 1.30 (P = .54).