Photo/Illutration An artist’s rendition of the Synfolium cardiovascular surgical patch, which is used to broaden blood vessels (Provided by Teijin Ltd.)

A new medical patch product, to be used surgically to broaden blood vessels in children with congenital heart disease, went on sale on June 12.

The release of Synfolium, as the surgical patch product is called, was announced during a news conference May 27 by officials of the three joint developers: Osaka Medical and Pharmaceutical University (OMPU); warp-knitted fabrics manufacturer Fukui Tateami Co.; and textile giant Teijin Ltd.

The Synfolium patch is designed to stretch to accommodate the growth of the patient’s body and is expected, among other things, to reduce the risk of the need for a second operation, the officials said.

Congenital heart disease, or abnormal formation of the heart and blood vessels at birth, is believed to occur in one in about 100 children.

Some patients of the disease undergo surgery at a very young age to have their blood vessels widened or their blood flow channels restored.

Medical patches, used surgically to broaden blood vessels, have conventionally been made from processed cow heart membranes and from synthetic materials.

A reoperation, however, is often required because a patch doesn’t stretch even as the heart grows in size along with the rest of the body, and also because the materials deteriorate.

Synfolium has a skeleton knitted with two types of yarns, one of which is decomposed and absorbed in the organism whereas the other is not decomposed, and coated with a gelatin film.

The patient’s own cells replace the gelatin and turn into blood vessel walls some three months after surgery. The bioabsorbable yarns decompose in about two years.

The product is woven in such a way that the entire fabric stretches more than twofold when only the nonabsorbable yarns have been left of its skeleton, the officials said.

Use of the patch product is expected to reduce the risk of a reoperation partly because it ends up being coated with the patient’s own cells, making material deterioration less likely, and partly also because the patch extends in size, the officials explained.

A review report of the Pharmaceuticals and Medical Devices Agency said that 34 patients participated in a clinical trial, which started in Japan in 2019.

None of the trial subjects had suffered serious problems that would have been attributed to defects of the patch, including death or the need for a second operation, following one year after surgery.

Surveys taken when two years had elapsed after surgery also showed that nobody had died or undergone a reoperation, even though two of the subjects had had to undergo a reintervention.

The review report said that Synfolium “is expected to demonstrate” its advantages, including reduced material deterioration and extensibility to accommodate growth.

However, the report also pointed out it is important to continue gathering longer-term data because the clinical trial was limited both in the number of subjects and the duration.

Teijin plans to study the results of product use for five years after surgery, in 150 cases in Japan, in the coming years to collect longer-term data, which is lacking.

Teijin will also enter talks with the regulative authorities for obtaining regulatory approval in the United States, Europe and elsewhere, the officials added.

Shintaro Nemoto, an OMPU professor of pediatric cardiovascular surgery, emphasized the role the participant businesses played in the development of the new product.

“If a reoperation on the heart is avoided, it is the best. But the market size is so small that addressing the issue does not pay off commercially,” he said. “Fukui Tateami and Teijin came forward to work on the project despite all that.”

Nemoto said, at the same time, that longer-term results have yet to come.

“Our product will face a test of its true value several years from now,” he said. “I am feeling huge responsibilities for that.”

The Synfolium patch was designed based on Fukui Tateami’s technologies.

The Fukui-based company served as the model for “Shitamachi Rocket: Gaudi Keikaku” (Downtown rocket: The Gaudi project), author Jun Ikeido’s work of fiction, which is available in the Japanese paperback edition from Shogakukan Inc.