Purpose: In low birth weight neonates primary ablation of posterior urethral valves represents a particular difficulty. The tiny caliber of the urethra presents a challenge for even the smallest commercially available pediatric resectoscope. Transurethral ablation by wired electrodes is difficult due to the narrow field of neonatal scopes with slow irrigation and restricted maneuverability. A Fogarty embolectomy catheter under fluoroscopic control does not allow direct visual assessment, and can be a lengthy procedure with numerous manipulations at the radiology suite. We describe a hybrid technique for primary valve ablation in neonates using a Fogarty catheter working retrograde under direct visual guidance of a neonatal cystoscope.
Materials and methods: A total of 17 low birth weight newborns (median 2,100 gm, range 1,760 to 2,690) underwent primary valve ablation using a 2Fr Fogarty catheter working through a 7.5Fr neonatal cystoscope with an offset lens. Both components were withdrawn as a single unit to avulse the valve leaflets under vision. Vesicoureteral reflux was present in 13 patients (76%) involving 24 renal units. A voiding cystourethrogram was performed 8 to 10 weeks postoperatively to delineate adequate decompression of the posterior urethra and mark the end point of the study in evaluating the efficiency of the technique.
Results: There were no immediate perioperative complications. Three patients died of causes unrelated to the procedure, leaving 14 boys (21 refluxing units) for evaluation. Voiding cystourethrogram revealed effective decompression of the posterior urethra with adequate drainage in all but 1 remaining patient (93%) due to a persistent left leaflet. Of 21 refluxing units reflux resolved in 6 (29%), was downgraded in 10 (48%) and remained unchanged in 5 (24%).
Conclusions: In low birth weight neonates primary valve ablation by a visually guided Fogarty catheter ensures effective disruption of the valvular obstructive mechanism. The technique maintains the transurethral visual standard and avoids the difficult manipulation of wired electrodes in a restricted field. It is devoid of radiation exposure and its simplicity enables safe performance at the neonatal intensive care unit, where the support needs of this fragile subset of patients are optimally provided for.