The problem with gastrostomy buttons
Pediatric surgeon Steven Moulton, MD, places a lot of gastrostomy buttons. Most pediatric surgeons do. Worldwide, about 2.5 million of these feeding tube devices will be placed or replaced this year. That figure is expected to exceed 3.5 million by 2021.
“And they’re fraught with problems,” says Dr. Moulton, who also serves as Director of Children’s Hospital Colorado’s Trauma and Burn programs. “If you make a new hole in the stomach, it’s going to leak. The gastric contents are acidic, which can cause a skin rash. It’s moist, so that can lead to a skin infection. And gastrostomy buttons can be accidentally dislodged. I often overhear nurses on the phone with parents, who have constant problems with these devices. And the only things we’re giving parents to secure them are tape and gauze. I thought, ‘There has to be a better way.’”
Gastrostomy button solution
A $25,000 seed funding grant was enough to pull together a team of mechanical engineering graduate students at the University of Colorado Boulder. The problem was a complicated one.
“We had to balance securing the gastrostomy button with facilitating changing the gauze pad and stabilizing the device. It needed to provide ventilation for the gastrostomy site, and it had to be childproof. We also wanted at least one component to be reusable,” says Dr. Moulton. “We went through hundreds of iterations. Hundreds.”
One discovery, suggested by research assistant Tyler Mironuck, was an inner structure that acts as a guide for securing the gastrostomy device and facilitates replacing the gauze sponge around the button’s stem.
The resulting device, known as the Button Huggie, won the Children’s Colorado’s Center for Innovation Challenge in 2019, providing an additional $40,000 in funding. These funds are being used to support a 200-patient clinical trial that will start this fall at several pediatric hospitals, including Children’s Colorado, Phoenix Children’s, Primary Children’s and Stanford Children’s.
Central venous catheter solution: The Snuggie
Under Food and Drug Administration rules, the Button Huggie didn’t count as a new device, since its purpose was to secure a device that was already cleared by the FDA. That saved considerable time and expense in the approval process. And it got Dr. Moulton thinking: What other surgical devices need to be secured?
One obvious choice was external tunneled central venous catheters, which are inserted in a vein to facilitate access for chemotherapy, lab draws and a host of other applications. These are held in place by a Dacron cuff under the skin. Over the course of about four weeks, subcutaneous tissue grows into the cuff and secures the catheter. The trouble is those four weeks.
“And if the patient is sick or immunocompromised, it could be eight weeks or longer,” says Dr. Moulton. “And in the meantime, the catheter is just dangling, waiting to get caught on something.”
There’s also the risk of bacteria migrating up the catheter and around the unsecured cuff, infecting the bloodstream.
With a $25,000 grant from the Children’s Colorado Center for Children’s Surgery, Dr. Moulton assembled another team at CU Boulder with a new challenge and a new set of requirements. The securement device could not change the method nurses were familiar with for dressing the exit site. Nor could it crimp or in any way damage the catheter, which could cause blood leakage or infection or require an operation to replace the damaged catheter.
“The design we came up with is completely separate from the exit site, so it doesn’t change the method of dressing at all,” Dr. Moulton says. “And it simplifies the management of the hub and greatly reduces the chances of dislodgement.”
A 20-patient clinical trial to test the first Snuggie prototype device will start in the next month or two.