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when the duct is large and the recurrent laryngeal nerve has an unusual course Ligation of the descending aorta can occur, especially when the duct is approached from a median sternotomy Signs of aortic coarctation may also be unmasked after ductal ligation.140,141 This is a constant hazard in the premature infant Abnormal findings after ductal ligation, such as decreased femoral pulses or declining urinary output, should prompt rapid reevaluation Video-assisted thorascopic closure without thoracotomy has been a recent innovation, first reported by Laborde and his colleagues.142 Clinical evidence of successful closure was found in all, although two attempts were necessary in two patients Damage to the recurrent laryngeal nerve occurred in one, and four suffered pneumothorax Increasing experience with the procedure has reduced the incidence of complications Continued experience has shown this approach to shorten hospital stay and to provide a cost-effective, safe, and rapid technique compared with open thoracotomy.143 Results are comparable with transcatheter closure.144,145 Recently developed for the neonate and infant, a transaxillary muscle-sparing thoracotomy provides excellent exposure for ductal division, produces less postoperative pain, and achieves an acceptable cosmetic result.146 Closure in the Catheterization Laboratory (see also Chapter 18) The percutaneous methods for closure were pioneered by Portsmann,147 who reported use of a conical Ivalon plug in 1967, with an umbrella-type device subsequently being used in 1979 by Rashkind and Cuaso.148 Both these implants required large sheaths for introduction and were often associated with residual shunting In 1992 the use of spring coils was reported,149 and due to the technical simplicity of insertion, this became a widely used technique for closure for small-to-moderate sized ducts In the ensuing years, a number of devices and techniques have been developed to close larger ducts As a result, transcatheter closure has become the treatment of choice for most children and adults with patent ducts In particular, percutaneous techniques offer considerable advantages over surgical closure for patients with a calcified ductal, wall with or without increased pulmonary vascular resistance,100,150,151 because the latter often necessitates cardiopulmonary bypass The essentials of the technique, regardless of the implant used, are to place a catheter or delivery sheath across the duct from either the pulmonary artery or the aorta and position the implant in the duct Several techniques have been developed to stabilize the coils during delivery because nondetachable Gianturco coils could migrate or assume unacceptable configurations or positions.152–154 Varieties of detachable coils are now available, which allow control of positioning prior to their release (Fig 41.16) FIG 41.16 Left, Detachable Gianturco coil used for ductal occlusion Note the Dacron fibers, which promote thrombosis, along its length Middle and right, Retrograde lateral aortograms before and after occlusion with such a spring coil The Nit-Occlud (pfm—Produkte für die Medizin) is a spring coil specifically designed for ductal embolization.155 The design is biconical, in contrast to the cylindric Gianturco coil (Fig 41.17) The Amplatzer Ductal Occluder (Abbott) is a plug-like design made of nitinol wire woven into a mesh in the shape of a mushroom-shaped plug (Fig 41.18; video 41.1) This device can be effective in larger ducts.156 The device has a detachable cable allowing repositioning or retrieval as necessary A modified Amplatzer Duct Occluder has a retention skirt with an angle and concavity to fit the aortic end, and a double retention disc design is available for clinical use.157 Other devices currently in use, or under investigation, include a modified buttoned device and the wireless patch developed by Sideris and associates.158 For low birth weight infants and newborns, smaller designs have become available for implantation, as well as a variety of vascular plugs to address the unique ductal morphologies that may present.159 Given the variety of ductal configurations and sizes, it is apparent that no individual device will be optimal for closure in all patients The availability of a variety of implants enhances the capability to close the majority of lesions FIG 41.17 Left, Nit-Occlud PDA occlusion device, with its biconical configuration Note the reversed winding on the proximal end Middle and right, Lateral aortograms before and after occlusion with the device (Modified from Schneider DJ, Moore JW Patent ductus arteriosus Circulation 2006;114:1873–1882) FIG 41.18 Left, Amplatzer Duct Occlude Note the mesh-like weave retention disc that is placed in the aortic end of the duct (middle) and the control cable Right, Newest design (Duct Occlude II, Abbott), with two retention discs, designed to avoid embolization The results of transcatheter occlusion have been excellent in infants through adulthood Complete closure rates at follow-up exceed 90% to 95% in most studies through adulthood.160–162 Because of modifications in design, development of new techniques, and increased skill of operators, rates of complete closure have improved significantly over time Serious complications of transcatheter closure are rare The most common complication is embolization of the device, which was relatively common early in the experience with coils Embolized coils can be retrieved, but even when they cannot, adverse