Metoclopramide Versus Placebo for GJ Placement

Overview

The goal of this study is to determine whether use of promotility agents to stimulate gastric peristalsis can reduce fluoroscopy time and procedure time during gastrojejunostomy (GJ) tubes placement in interventional radiology (IR). The investigators hypothesize that increased gastric peristalsis will aid in advancing a guidewire through the pylorus, a time consuming and tedious step required during GJ tube placement. In order to maximize scientific rigor and clinical practice impact, the investigators aim to answer this question through a blinded, randomized, placebo controlled trial. Specific Aim 1: To test the hypothesis that a single dose of IV metoclopramide immediately prior to GJ tube placement reduces the fluoroscopy time required to advance a guidewire through the pylorus. Specific Aim 2: To determine whether a single dose of IV metoclopramide immediately prior to GJ tube placement reduces total procedure fluoroscopy time, air kerma and total procedure time. Specific Aim 3: To assess the safety of a single dose of promotility agent prior to GJ tube placement by assessing rates of adverse events in the periprocedural period in patients receiving IV metoclopramide versus placebo.

Gastrojejunostomy tube placement is a commonly performed procedure for providing nutritional support in patients unable to tolerate gastric feeds due to gastric outlet or duodenal obstruction or severe gastroesophageal reflux. When performed percutaneously, this procedure involves advancing a guidewire from the gastrostomy skin entry site through the pylorus. Based on data collected for quality improvement purposes the investigators have found that this step accounts for approximately one half the total fluoroscopy time and radiation dose during GJ tube placement and approximately one third of the total physician time in the procedure. Specifically, crossing the pylorus required on average 5.3 minutes of fluoroscopy time out of a total of 9.3 minutes for the entire procedure, and accounted for 92.2 mGy air kerma out of 201.7 mGy for the entire procedure. Furthermore, inability to advance a wire into the duodenum due to refractory pylorospasm is among the most common reasons for aborting GJ placement. Specifically, in approximately 1.5% of GJ placement procedures the pylorus cannot be crossed and a gastrostomy tube is placed instead. Only colonic interposition, in which GJ tube placement is not attempted, accounts for a larger fraction of failed procedures (3%). A variety of wire, catheter, and device related techniques have been described to facilitate wire intubation of the pylorus, but this remains a rate limiting step in the procedure. In order to reduce radiation doses to both the patient and interventional radiologist to levels that are as low as reasonably achievable and to maximize procedural success rates, adjunctive methods to aid in wire intubation of the pylorus are needed. Previous meta-analyses of randomized controlled trials have found that a single dose of erythromycin or metoclopramide is effective at emptying the stomach of blood and improving visualization during endoscopy for upper gastrointestinal tract bleeding. Similarly, a previous randomized controlled trial demonstrated that a single dose of metoclopramide or domperidone increases the rate at which nasoenteric tubes spontaneously pass through the pylorus from 27 to 55%. Single dose metoclopramide is also indicated for reducing transit time during small bowel follow through examinations. Drug related adverse events in these studies were rare. Although single dose promotility agents are established in the above described settings, they have not been studied for GJ tube placement. The investigators hypothesize that use of promotility agents may facilitate advancement of the guidewire through the duodenum and into the proximal jejunum during GJ tube placement by enhancing gastric peristalsis, pylorus relaxation, and small bowel motility. Single doses of promotility agents such as metoclopramide are inexpensive (approximately $1.02 per dose), easily administered at the time of the procedure, and have very favorable safety profiles. Therefore, promotility agents may represent a simple, effective, and readily feasible means of reducing radiation dose and procedure time during GJ tube placement, thus improving the safety and efficiency of this common IR procedure.