Biologic Envelope Cuts Complications After Cardiac Device Implantation

NEW ORLEANS -- Use of a biologic envelope during initial placement of cardiac implantable electronic devices (CIEDs) led to multiple improvements at subsequent reoperations, including a reduced need for capsulectomy, researchers reported.

In a small study, only one of 11 patients who received the CanGaroo biologic envelope required capsulectomy, as compared with eight of 15 who received a synthetic product (P<0.05) and seven of 17 who got no envelope, according to John Catanzaro, MD, of University of Florida Health in Jacksonville.

"This strategy takes advantage of something that is naturally biologic rather than using nothing or using something that is synthetic," he told MedPage Today at the Heart Rhythm Society (HRS) meeting.

In an HRS poster, Catanzaro and colleagues also reported that biologic envelope use was linked with fewer lead adhesions, easier generator and lead mobilization, and thinner tissue capsules.

He estimated that around 300,000 CIEDs are implanted in the U.S. annually, with about 2% to 3% of patients experiencing infectious complications, some of which can be serious or fatal. Catanzaro noted that newer more complex devices are in development and on the market and many have multiple leads. "Lead burden is a risk factor for infection," he said.

The FDA-cleared CanGaroo is "made from pig intestine," Catanzaro said, "and when it is implanted it makes contact with the internal skin or tissue and it shifts the response from an inflammatory to non-inflammatory state. On the other hand, the synthetic envelope can lead to inflammation and development of fibrosis, and fibrosis can be a nidus for infection."

Fred Kusumoto, MD, of the Mayo Clinic Jacksonville in Florida and the immediate past president of HRS, told MedPage Today that "this is a nifty concept that has the potential to reduce infection among patients who need changes in their implanted cardiac-related devices."

He agreed with Catanzaro that "these infections can be a very, very large problem. Any strategy to reduce infection rates in these patients is important."

The current national, multi-center study (HEAL) evaluated patients who previously underwent implantation of a CIED with the CanGaroo biologic envelope, a non-biologic envelope, or no envelope, and returned for revision at least 4 months after initial placement.

Catanzaro's group reported no significant differences among patients in the three groups for age, sex, race, or prior implant history.

They did find that lead adhesion classification, based on a semi-qualitative subjective scale from 0-3, was scored as significantly less severe in the biologic envelope group versus the no-envelope group (score of 1 vs 2).

Also, compared with no envelope, physicians scored biologic envelope reoperations as having 46% easier generator mobilization (P=0.02), 41% easier lead mobilization (P=0.01), and 43% less overall procedural difficulty (P=0.04), on a 10-point scale where higher scores indicate a greater degree of difficulty. Scores were also numerically lower for the biologic envelope versus synthetic envelope.

"The HEAL data further support the potential of biologic envelopes to enhance pocket healing during cardiac device implantation and simplify reoperative procedures," said Catanzaro. "This study demonstrates that biologic envelopes, such as CanGaroo, can improve patient care and decrease complications following device implantation."

Comment