Boston Scientific's ($BSX) stroke-fighting left atrial appendage closure device, the Watchman, suffered from an FDA rejection and other regulatory delays. It was approved this year, 10 years after achieving the milestone in Europe. But a left atrial appendage suture system, known as the Lariat, walked through the far easier 510(k) pathway, which typically does not require human clinical trials. In July, the FDA issued a safety notice about the Lariat that has resulted in far reduced usage of the device. "This is one of the most complex procedures that you could perform in our field," said interventional cardiologist Dr. Jay Giri, "The Lariat was considered an intermediate-risk device. The question now becomes, why would that possibly be the case?" Indeed, FDA concerns related to the Watchman's implantation procedure were one of the main reasons for the device's delay. Boston Scientific isn't indicating any annoyance at the FDA for the differential treatment, which may have resulted in patient injury(or worse) from the Lariat. And that device isn't the only 510(k)-cleared left atrial appendage closure device to cause injury. Earlier this year, the FDA announced the recall of all 4,154 units of Maquet's stroke-fighting TigerPaw System II left atrial appendage closure device. It is is one of several devices classified by the FDA as a low to moderate risk "implantable staple." More