With the widespread use of indwelling central venous catheters for chemotherapy, hyperalimentation, and monitoring and the use of coils and other devices for occlusion, removal of embolized foreign bodies in the central and peripheral circulation is often performed in the catheterization laboratory Most of the foreign bodies and devices are radiopaque in parts, if not in their entirety, and can be easily identified on radiography Various devices based on those used in urologic practice have been used for retrieval Depending upon the location of the foreign body to be retrieved, access is achieved in arterial or venous circulation Usually, two routes are used for access, one with the device, and the other for multiple angiograms to assess proximity to the foreign body Snares are the most versatile and commonly used devices They function like a lasso, encircling and tightening around the object to be retrieved The snare is delivered through a large sheath to the reach the foreign body Once snared, the foreign body is pulled into the sheath and removed from the circulation Basket devices were designed for removal of biliary and renal stones They are made of multiple wires arranged to protrude in different directions and then converge to form a basket that can hold devices They can be used to retrieve larger foreign bodies that can be compressed and may need larger bore sheaths Forceps, either specifically designed for retrieval or those used for endomyocardial biopsy, have also been used.174 The risk of vascular trauma during retrieval should be borne in mind and surgical removal of a foreign body considered if interventional techniques fail Interventions on Surgical and Other Naturally Occurring Abnormal Pathways Coils and devices made of nitinol have been used to occlude other structures with abnormal vascular communications, including systemic or pulmonary arteriovenous fistulas, venovenous (Fig 18.27) or venoarterial communications,175 aortopulmonary shunts, and systemic-to-pulmonary collateral arteries (Fig 18.28).176,177 Closure of surgically created fenestrations in the Fontan circulation can be successfully performed with a wide variety of devices The Amplatz atrial septal occluder (Fig 18.29) and Cardioform septal occluder (Fig 18.30) are the most commonly used.178,179 A careful hemodynamic assessment should be performed before occluding the fenestration A test occlusion of the fenestration with a balloon catheter, with a subsequent rise in systemic arterial saturations, should be performed Measurement of systemic venous saturations to assess the arteriovenous oxygen difference serves as a surrogate for the cardiac output An increase of more than 1 to 2 mm Hg or, more importantly, a decrease in the cardiac output after test occlusion of the fenestration is considered contraindications to closure of fenestration FIG 18.27 Occlusion of a systemic-to-pulmonary venous collateral vessel in the Fontan circulation to reduce systemic arterial desaturation FIG 18.28 Occlusion of a systemic-to-pulmonary collateral artery from the descending aorta with an Amplatz duct occluder