Clipping of complex aneurysms with fenestration tubes: application and assessment of three types of clip techniques

Straight fenestrated clips can be stacked to create tubes that reconstruct origins of branch arteries at the necks of complex aneurysms. Three variations of fenestration tubes were conceived and applied to a consecutive series of patients with aneurysms to determine their usefulness.

Antegrade fenestration tubes are built with stacked, straight fenestrated clips with an open tube transmitting the efferent artery with forward blood flow. Retrograde fenestration tubes are also built with stacked, straight fenestrated clips, but the fenestration tube is closed with a nonfenestrated clip to reverse the direction of blood flow into the efferent artery that exits from the base of the tube. Aneurysm dome fenestration tubes encircle the dome rather than transmitting an efferent artery and use the tips of stacked, straight fenestrated clips to reconstruct the aneurysm neck.

During a 2-year period in which 465 aneurysms were treated microsurgically, 25 patients had 26 aneurysms clipped with fenestration tubes (antegrade tubes, 15 aneurysms; retrograde tubes, four aneurysms; dome tubes, seven aneurysms). Angiographically, 92% of the aneurysms were completely eliminated with no branch artery occlusions. Neurologically, good outcomes were observed in 84% of the patients (Glasgow Outcome Scale score 5 or 4) with 96% either improved or unchanged.

Clip reconstruction with fenestration tubes is another microsurgical technique that can be used to treat aneurysms with large or giant-sized efferent arteries that adhere to the aneurysm and/or unusual branch anatomy. Fenestration tubes are safe and effective, and they are used more frequently than expected for what might seem to be a subtle technical nuance. This technique relies on intraoperative adjuncts such as temporary clipping, careful application of clips to preserve the patency of branch arteries, and technology to detect inadvertent branch occlusions.