Akron, Ohio — Medical product designer Len Czuba gave a history of vinyl in medical devices at the Vinyltec conference, and he strongly supported vinyl as the most reliable, cost-effective material for IV and blood bags, catheters and other medical devices.
Czuba thinks vinyl will be around for a long time in medical products, despite what he called often misleading attacks from environmentalists who cite the vinyl plasticizer DEHP — di(2-ethylhexyl) phthalate — as a grave health risk.
"So what makes PVC the material of choice? I believe the fact that it's both visually clear, soft and flexible, it can be easily and repeatedly RF [radio-frequency] sealed," he said at the conference. "It's even solvent-bondable with a lot of the components that are injection molded for using with PVC." Czuba said PVC medical devises can be steam sterilized and, if properly formatted, can be radiation sterilized.
Plus, he said, replacements to PVC do not have the same level of clarity, and they either cannot be RF sealed or RF sealing is very slow or difficult to do.
Czuba reviewed the history of PVC in medical devices in a presentation Oct. 3, the second day of the Vinyltec conference in Akron. He worked for 20 years at Baxter Healthcare Corp., looking at vinyl and possible alternatives for much of that time.
It started with Louis Pasteur, who Czuba said is considered the father of microbiology. In the late 1800s, he realized that bacteria were responsible for disease. His process of pasteurization, or heating foods and beverages to kill the germs, was picked up by the medical sector for sterilizing glass bottles with rubber stoppers and tubing made from rubber, glass or stainless steel.
During the Korean War, battlefield mobile army hospitals recognized that the glass bottles were too fragile for intravenous fluids and blood, Czuba said.
Dr. Carl Walter invented the idea of a flexible blood bag in the 1950s. In the late 1960s and early 1970s, David Bellamy developed the first PVC blood bag for Baxter Healthcare. The Food and Drug Administration approved the vinyl IV solution bag in 1972.
The flood gates opened as PVC rapidly replaced glass, said Czuba, who joined Baxter Healthcare in 1974 as senior development engineer. Baxter transitioned to PVC bags to package its mass-produced, sterilized IV solutions.
The PVC for bags and flexible tubing could not only be RF sealed, but you can seal a drip chamber to control the rate of fluid dispensing, Czuba said. An entire field of accessory products made of PVC emerged and spread throughout healthcare.
"[PVC] became ubiquitous throughout the health community from surgical suites to emergency rooms, clinics, ambulances and even these days into home health care and the dental market," Czuba said. Blood stored in PVC bags can be stored for 35 days, which has saved lives, he said.
Over the years, PVC systems have improved, so bags were made thinner and stronger, Czuba said. But they've come under attack because of DEHP, which has been widely studied. Czuba said DEHP is not a problem with IV solutions, but blood and chemotherapy solutions do absorb a small amount of the plasticizer.
U.S. Surgeon General C. Everett Koop and a panel convened by the American Council on Science and Health reviewed scientific literature on phthalates and concluded that medical devices, as well as vinyl toys, are safe. In PVC medical products, dosage levels are low, and PVC gives significant health benefits.
Czuba said the panel recommended to the FDA that there is no reason to eliminate DEHP. Exceptions were made for infants and for chemo drugs, which have substances that draw out the plasticizer, he said.
Czuba said the PVC medical products are still going strong since the blood bag was commercialized.
"Fifty years later and still the major part of the medical device community uses flexible PVC in most of its products. So, it may be a concern — and in fact if you go online, that's all you read about is the hazards of phthalate plasticizer in PVC medical devices," Czuba said. "Fact is, so far, even the FDA, which was requested to look at the safety of PVC, found it to be safe for use in its intended uses right now."
