USE OF INTRAVASCULAR STENTS IN SYSTEMIC VENOUS AND SYSTEMIC VENOUS BAFFLE OBSTRUCTIONS - SHORT-TERM FOLLOW-UP RESULTS

Background Balloon-expandable intravascular stents are well accepted i n the management of arterial obstructions. This study was undertaken t o detail the immediate and short-term results of intravascular stent i mplantation in systemic venous and systemic venous baffle obstructions in children. Methods and Results Between September 1991 and June 1994 , 12 patients had 21 stents implanted in 13 systemic venous obstructio ns, 1 patient having stents placed in 2 separate obstructions. In the baffle group, 4 of 13 obstructions were at the superior vena cava/righ t atrial junction after atrial baffling for transposition of the great arteries. One of 4 patients had complete obstruction requiring transs eptal needle perforation before stent implantation. There was an immed iate gradient reduction from 12 +/- 8.4 mm Hg (range, 4 to 20 mm Hg) t o 1.3 +/- 1.9 mm Hg (range, 0 to 4 mm Hg, P=.05). The obstructed segme nt diameter increased from 3.5 +/- 3.9 mm (range, 0 to 8.5 mm) to 16 /- 2.7 mm (range, 14 to 20 mm, P=.002). In the central vein group, 9 o f 13 obstructions were in large central veins. Three of 9 patients had complete obstruction requiring transseptal needle perforation before stent implantation. There was an immediate gradient reduction from 10. 3 +/- 8.5 mm Hg (range, 0 to 20 mm Hg) to 0.8 +/- 1.1 mm Hg (range, 0 to 3 mm Hg, P=.005). The obstructed segment diameter increased from 1. 3 +/- 1.1 mm (range, 0 to 2.8 mm) to 9.4 +/- 1.7 mm (range, 7.6 to 12 mm, P<.001). There were no acute complications in either group. In the follow-up group, patients were scheduled for clinical follow-up at 3, 6, and 12 months with echocardiography or magnetic resonance imaging (MRI) at 3 or 6 months and for repeat cardiac catheterization at 12 mo nths. All stents were patent by echocardiography or MRI when studied a t follow-up. Cardiac catheterization in 6 of 12 patients, 2 to 13 mont hs after stent, demonstrated that all stents remained patent without c ompression or fracture. Follow-up and immediate poststent gradients we re not significantly different (1 +/- 1.6 versus 0.7 +/- 1.2 mm Hg, P= NS). Neointimal hyperplasia (5 of 6 patients) reduced the stent lumen only from 12.5 +/- 4.7 mm (range, 8 to 20 mm) to 10.6 +/- 4.7 mm (rang e, 4.5 to 17.7 mm, P=NS). No stents required redilation. One of 18 ste nts placed in series had ''unlocked'' and rotated in the venous lumen but remained fully patent to flow. Conclusions Balloon-expandable intr avascular stents can be safely and effectively used to relieve systemi c venous and systemic venous baffle obstructions, even when obstructio n is complete. Short-term follow-up suggests excellent continued paten cy, but further follow-up is required to observe for progression of ne ointimal hyperplasia. We postulate that balloon-expandable intravascul ar stents will become the treatment of choice for the relief of select ed systemic venous and venous baffle obstructions in the pediatric pop ulation.