The Nit-Occlud® PFO device (Figs. 20.2 and 20.3) belongs to the “Nit-Occlud family” along with an ASD and PDA closure device. All these devices carry the typical feature of being constructed of Nitinol wire mesh without protruding clamps. As the wire mesh is solely composed of Nitinol, the device is flexible and can adapt well to the walls of the septum. The right atrial side of the device consists of a double-layer disc. The left atrial side of the device however comprises of only a single layered disc thus significantly reducing the amount of material implanted in the left atrium in order to provide lower thromboembolic risk. An integrated polyester membrane on the right atrial disc and a polyester membrane facing the left atrium are intended to accelerate endothelialisation. The Nit-Occlud® PFO received CE mark in July 2010 and is available in the following sizes: 20, 26 and 30 mm. The device comes pre-mounted on a 9 or 10 F implantation catheter. In order to assure optimal position, the device can be repositioned, withdrawn into the implantation sheath or removed, as long as the release mechanism is not yet triggered.

Sixty-three patients were included in a prospective, non-comparative, single-centre clinical investigation entitled “Procedural Success and Safety of the Nit-Occlud® PFO Closure Device and Its Application System” in Frankfurt, Germany to assess the effectiveness, safety and practicability of implantation of the Nit-Occlud PFO®. The primary endpoint was successful implantation without recurrent event, device malfunction, embolization or the need for a replacement device over 6 ± 2 weeks. All patients underwent transesophageal echocardiography (TEE) at 6-weeks, and 42 patients had repeat TEE at 6-months. Clinical follow-up at 18.7 ± 7.4 months was also performed. The device was successfully implanted in 62 (98.4 %) patients with no relevant procedural complications. At 6-week follow-up, 60 (95.2 %) patients met the primary endpoint. A residual shunt at rest and with Valsalva was noted in 8 (12.7 %) and 31 (49.2 %) patients respectively at 6-week TEE. At 6-months, one of 42 (2.4 %) and 9 of 42 (21.4 %) patients had a residual shunt at rest and with Valsava, respectively. At 18 months, 5/63 patients had recurrent events (3 TIAs, 2 strokes). No device-related complications occurred. One patient developed atrial fibrillation [2, 3].

The Lifetech PFO occluders have a unique ceramic deposition titanium nitrate (TiN) coating which in animal studies demonstrated prevention of nickel leaching, promotion of rapid endothelialization and complete defect closure in animal studies. The Nitinol layer of the occlude comprises of a transition layer followed by a layer of TiN coating which is only several nanometers thick and can decrease fracture rates while increasing elastic properties of the device. As seen in vitro thromboresistance testing, the lack of nickel leaching makes the substance less prone to corrosion and thrombus formation. Cera occluders are covered with TiN (Titanium nitride) coating presenting a golden-color. This coating greatly reduces the nickel released from the nitinol wire and thus, enhances biocompatibility

The CeraFlex^TM PFO device is the third generation of the Cera device (Fig. 20.4). A connecting mechanism between the device and the delivery wire allows free rotation of the device. During deployment of the device, the connecting mechanism allows for the device to return to its preset shape so that the physician can observe the exact position of device in the septum before finally releasing it. The device is available in four sizes: 18/18, 25/18, 30/30 and 35/25 mm, whereas the sizes correspond to left disc diameter/right disc diameters, respectively.