Percutaneous Techniques for Managing Maldeployed or Migrated Stents

Wandering stent within the pulmonary circulation

To present a case of a wandering stent within the pulmonary circulation that was managed conservatively with the "wait-and-see" strategy. Accidental dislodgement of a left brachiocephalic vein stent into the left lower lobe pulmonary artery occurred in an 83-year-old patient suffering from end-stage renal disease during placement of a left jugular vein catheter. The following day, a second X-ray revealed migration of the stent from the left to the right lower lobe pulmonary artery. Our patient was managed conservatively with low-molecular-weight heparin and was discharged on clopidogrel. The patient remained asymptomatic with regard to the migrated stent for four and a half years and died of old age. This is the first case of a wandering stent within the pulmonary circulation reported in the literature, supporting the "wait-and-see" policy in the management of such patients.

Percutaneous removal of a fully expanded SMART stent from the pulmonary artery using various adjunctive techniques

A 36-year-old man with an implanted arteriovenous shunt for hemodialysis was referred for shunt malfunction. Venography of the right upper extremity showed occlusion of the subclavian vein, and a SMART stent was deployed. The fully expanded stent immediately migrated centrally into the left pulmonary artery. As initial efforts to pass a snare over the stent failed, we intentionally passed a microguidewire through stent interstices, snared the end of the microguidewire to create a loop, and pulled the stent/microguidewire/snare combination back into the right ventricle where it separated from the loop because of stent mesh destruction. As the stent remained in the right ventricle, we advanced a 0.035-in. guidewire into the stent lumen, passed an angioplasty balloon over the guidewire, inflated the balloon in the stent, and performed pull-back into the right distal external iliac artery. The stent was then surgically removed via a right inguinal incision without eliciting any complications. Although retrieval of the stent malpositioned in the pulmonary artery was difficult, we retrieved it safely by applying various adjunctive techniques.

Successful treatment of type I endoleak of common iliac artery with balloon expandable stent (Palmaz XL stent) during endovascular aneurysm repair

Type 1 endoleak of common iliac artery (type I_b endoleak) should be treated during endovascular aneurysm repair (EVAR). An 86-year-old female was diagnosed with abdominal aortic aneurysm measuring 6.6 cm in diameter and right internal iliac artery aneurysm measuring 4.0 cm in diameter. She underwent EVAR after right internal iliac artery embolization. There was type I_b endoleak, which was repaired by balloon-expandable stent, Palmaz XL stent (Cordis). We report successful treatment of type I_b endoleak with Palmaz XL stent, which may be considered as an alternative option for type I_b endoleak after EVAR.

Techniques for removing bilateral renal artery stents prior to fenestrated endovascular aneurysm repair

PURPOSE

To demonstrate 2 endovascular methods for successful intravascular stent extraction.

TECHNIQUE

In preparation for fenestrated endovascular aneurysm repair, renal artery stents may be implanted for focal vessel stenosis at the ostium. In a recent case, bilateral renal artery stents were deployed with >50% protruding into the aortic lumen, thus rendering fenestrated endografting impossible. Two techniques were employed to extract the stents. In the left renal artery, the stent was extracted using an endovascular snare, but the right renal artery stent could not be removed with this method. Instead, an endoscopic forceps was advanced down a 16-F sheath, and the stent was grasped, extracted, and released into the aneurysm sac. The endovascular repair then proceeded in the usual fashion.

CONCLUSION

The need to remove a stent prior to endovascular aneurysm repair is not a common problem encountered by most endovascular specialists; however, these methods should be in their armamentarium should the need arise.

Comparison of the Texan Foreign Body Retrieval Device and the Amplatz Goose Neck Snare in Vivo and in Vitro

PURPOSE

To compare the capturing ability of the Texan foreign body retrieval device with that of the Amplatz gooseneck snare in a swine model and to analyze their capturing mechanisms.

MATERIALS AND METHODS

The Texan device with a < or = 30-mm adjustable loop was compared with the 5-mm, 15-mm, and 35-mm Amplatz snares for retrieval of foreign bodies from the iliac vein, infrarenal aorta, inferior vena cava, and stomach. Capture times by two investigators were compared.

RESULTS

All 24 attempts with the Texan device were successful, as were 21 of 23 attempts with the Amplatz snare; two attempts with the 5-mm Amplatz snare were abandoned, and the failures were attributed to the suboptimal size of the snare. Other than the two abandoned attempts, there was no difference between the capturing performances of the Texan device and the 5-mm, 15-mm, and 35-mm Amplatz snares when they were compared side by side. In all vascular interventions, however, the Texan device performed significantly better in capture times than did the 5-mm and 15-mm Amplatz snare (P = .015). In all interventions, the Texan device performed significantly better in capture times than did all three sizes of the Amplatz snare (P= .012).

CONCLUSION

The overall performance of the Texan device based on its capturing ability was significantly better than that of the Amplatz snares. The adjustability of the loop and the more versatile capturing technique made capture and retrieval of foreign bodies easier.