STENT IMPLANTATION FOR RELIEF OF PULMONARY-ARTERY STENOSIS - IMMEDIATE AND SHORT-TERM RESULTS

Our objective was to assess the immediate and short-term results of st ent implantation to relieve pulmonary artery stenosis (PAS). Thirty-se ven patients underwent an attempt at stent implantation at a median ag e of 7.0 years (range, 0.8-31.4 years) and a median weight of 20.5 kg (range, 7.4-85 kg). Twenty-two patients had previous tetralogy of Fall ot repair. A total of 55 stents were implanted successfully in 36 pati ents. The peak systolic gradient across the stenotic segment decreased from a mean of 43 +/- 20.4 mmHg prestent to 13 +/- 13.9 mmHg (P < 0.0 01) poststent. The diameter of the narrowest segment increased from a mean of 4.8 +/- 1.6 mm to 10.5 +/- 2.6 mm (P < 0.001). The right ventr icular-to-aortic mean systolic pressure ratio decreased from 0.74 +/- 0.2 to 0.52 +/- 0.19 (P < 0.001). Complications included balloon ruptu re prior to full stent expansion in 4 patients (in 2 patients the sten t was positioned in the superior vena cava, and in 2 in the inferior v ena cave), distal migration of a stent which was successfully retrieve d at surgery 1 mo later In 1 patient, and tethering of the stent to th e balloon requiring surgical removal in 1 patient. One patient died se veral hours after stent placement. Sixteen patients underwent repeat c atheterization ata mean follow-up interval of 0.9 +/- 0.5 years (range , 0.2-2.0 years). The mean gradient across the stent for these 16 pati ents was 26.7 +/- 19.8 mmHg, and there was no change in the mean diame ter (9.4 +/- 3.2 mm). Two patients developed stenosis related to neoin timal proliferation at the stent site which was redilated successfully . In conclusion, stent implantation is generally safe and effective in relieving PAS. (C) 1996 Wiley-Liss, Inc.