SACRAL AGENESIS: CLINIMETRIC EXPERIENCE AND OUTCOME

Background: Sacral agenesis, a rare anomaly, may occur as an isolated lesion or in conjunction with other syndromes of caudal regression. Patients with this disorder often have varying degrees of vesical dysfunction. The goals of long-term urological management include maintenance of stable bladder function and preservation of upper tracts. Clinimetrics refers to the physiologic measurements as applied to medicine. Since its inception in the nineteenth century, clinimetrics has transformed the practice of medicine from a pastoral occupation to a science of precise observation and measurement. Patients and Methods: From 1984 to 1998, we evaluated 32 children (17 boys, 15 girls) with sacral agenesis. The age at initial evaluation ranged from 1 day to 18 years (mean 5.5 years). Associated genitourinary anomalies were present in 22 patients (69%) including vesicoureteral reflux, solitary kidney, undescended testis. Non-genitourinary anomalies were present in 18 patients (56%). Only four children had no associated anomalies. Results: All patients were evaluated with renal ultrasound, cystometrogram, and voiding cystourethrogram. The mean follow-up was 7.2 years (range 1 week to 14 years). Twenty five (78%) have maintained native bladders while 7 children underwent surgery for small capacity bladder (augmentation cystoplasty-5; ileal conduit-1; cutaneous vesicostomy-1). Of the 27 pts. where pressure based bladder capacity could be measured, only 3 children were within the age expected bladder capacity; all others had an average of 56% below the age expected bladder capacity. Urinary continence was evaluated in 26 patients (excluded were children with age appropriate diaper voiding-4; urinary diversion-2). Fifteen are dry on intermittent catheterization; 6 require used of pads; 5 are managed with pull-ups; none showed normal voiding. Bladder outlet procedures included PV sling (3 pts.) and collagen injection (3 pts.). There was no evidence of hydronephrosis secondary to reservoir noncompliance or bladder outlet obstruction. Most patients have maintained stable renal function and renal growth. Two patients had scarring to the refluxing units with one eventually requiring nephrectomy for chronic infection. Discussion: The clinimetric approach has shown that unlike the high pressure noncompliant bladders often seen in children with myelodysplasia, sacral agenesis patients have low pressure, open outlet reservoirs. The absence of any hostile bladders among our patien