Long term follow-up and treatment of antenatally diagnosed unilateral hydronephrosis

Abstract

Objective To investigate the outcome and treatment of neonates bom with isolated unilateral hydronephrosis diagnosed antenatally.Methods We retrospectively reviewed the casenotes of 692 children (541males and 151 females) between january 1988 and January 2010,who had been diagnosed antenatally with isolated,unilateral hydronephrosis and the diagnosis was subsequently confirmed posmatally.The follow up time was 12 months - 22 years (mean 142 months).All patients were followed up with ultrasonography and dynamic renal imaging.Hydronephrosis was assessed and classified according to the Society of Fetal Urology (SFU) grading system.Results Stabilization occurred in all children with grade 1 hydronephrosis,in 87％ of children (155) with grade 2 hydronephrosis,and in 30％ of children (39) with grade 3 hydronephrosis.However,13％ of children (23) with grade 2 hydronephrosis,70％ of children (92) with grade 3 hydronephrosis,and 100％ of children with grade 4 hydronephrosis received surgical intervention according to our pre - detemfined criteria.107 patients (late pyeloplasty group) were treated due to a reduction in the differential renal function (DRF) to ＜40％,and 93 children (early pyeloplasty group) underwent surgery because of worsening hydronephrosis grades or failure to improve and had poor radiotracer clearance.In the early pyeloplasty groups,significant improvements were noted between postoperation and preoperation with respect to the DRF (45.8 ± 1.7％; 42.7 ± 2/％) and the ratio of the depth of the calyces to the thickness of the parenchyrna (C/P ratio) (0.7 ± 0.3; 2.0 ± 0.8,P＜0.05).The same results were seen in the late pyeloplasty group with respect to the DRF (38.4 ± 2.6％ ; 36.4 ± 3.3％ ) and C/P ratio ( 1.3 ±0.5; 2.4 ± 0.8,P＜0.05).The DRF was better in the early pyeloplasty group than the late pyeloplasty group.The improvement in DRF was significant during the first year post- operatively(48.8 ±4.3％) and became stable thereafter.The C/P ratio was inversely correlated with the DRF in the patients before and after pyeloplasty (r =- 0.26,P =0.01 ; and r =- 0.62,P =0.001,respectively).Conclusions All infants with SFU- 1 and most infants with SFU - 2 hydronephrosis do not need an invasive procedure.Although greater improvement occurred in patients with an initial DRF＜40％,the reduced DRF did not recover to the pre- deterioration level post- operatively.Earlier surgical intervention after a short period of strict clinical surveillance is beneficial for preserving renal function in patients with persistent SFU - 3 or SFU - 4 hydronephrosis. Key words: Fetus; Hydronephrosis; Uhrasonography; Renal dynamic imaging; Follow-up