Patients who empty their stomach slowly may have what we call "Slow gastric emptying" or "gastroparesis". These patients can have some changes in the thickness of their stomach wall. In addition, they may have loss of some important nerve cells in their stomach muscles. The loss of these cells can cause slow emptying of the stomach. Obtaining a sample from the stomach wall to examine the loss of these cells can help in diagnosing gastroparesis. Up to now, the only way to obtain a tissue sample from the stomach muscle was to undergo an operation in the surgery suite and be hospitalized for several days after the procedure. Usually, we obtain this sample while these patients are having a surgery for another purpose such as placement of a gastric stimulator (a machine which is inserted in the stomach wall to control the stomach rhythm and thus help the stomach to empty faster). Endoscopic ultrasound is an endoscope (a tube with a source of light and ultrasound installed in the tip of the tube) that can measure how thick the stomach wall is and can provide sample "biopsies" of the stomach wall which can be studied for the loss of these specialized muscles and cells.

We are proposing that samples obtained by the endoscopic ultrasound can be sufficient to diagnose "gastroparesis" and can replace the need for obtaining samples by surgery. Endoscopic ultrasound is an outpatient procedure which is not as invasive as surgery.

EUS Fine Needle Aspiration (FNA) Biopsies of the Muscularis Propria (MP) of the gastric wall in patients with gastroparesis (GP) could replace the routine use of surgical full thickness biopsies (FTB) for assessing loss of Interstitial Cell of Cajal (ICC) and cellular infiltrates in the myenteric plexus. The principal investigator investigated the efficacy and safety of EUS Fine Needle Aspiration biopsies of the Muscularis Propria of the stomach antrum in gastroparesis and compared the tissue to a surgically obtained full thickness biopsies in the same patient.

This was a prospective, nonrandomized, feasibility trial. Patients with gastroparesis who were undergoing gastric neurostimulator placement were enrolled. Patients had a gastric wall measurement by radial EUS in the body and antrum of the stomach followed by linear EUS examination and FNA of the muscularis propria in the antrum by using a 19-gauge core needle. Within 24 hours, a full-thickness biopsy specimen of the antrum was obtained surgically during neurostimulator placement. Endoscopic and surgical specimens were compared for tissue morphology, number of ICCs (c-kit stain) and enteric neurons (S-100 stain), and fibrosis (trichome) for each patient. The correlation coefficient of the ICC count per high-power field was used to compare both specimens. Continuous data were compared by using a t test.

Inclusion Criteria:

• Patients (age 18 to 80) with objective evidence of gastroparesis who will undergo surgical placement of gastric pacemaker and full thickness gastric wall biopsy. Objective evidence of gastroparesis include the following:

  1. Documented symptoms of gastroparesis for longer than 6 months.
  2. More than 7 episodes of vomiting per week
  3. Refractoriness or intolerance to antiemetics and prokinetic medications
  4. Delayed gastric emptying of solid meal (>60% gastric retention at 2 hours and >10% at 4 hours postprandial) using a standard 4-hour scintigraphic method

Exclusion Criteria:

• Patients with documented organic or intestinal pseudo-obstruction , primary eating or swallowing disorders, rumination syndrome, psychogenic vomiting, cyclic vomiting syndrome, systemic sclerosis, thyroid and adrenal disease, chemical dependency, cancer, peritoneal dialysis, pregnancy.Also, patients with history of gastric surgery such as partial gastric resection or vagatomy.