Correlation between the clinical features of patients with spina bifida and the findings of DMSA scintigraphy
摘要
In patients with spina bifida (SB), even if kidney function is normal at birth, the risk of developing chronic kidney failure later in life is high due to neurogenic deficits that impair bladder emptying as the child grows. The aim of this study is to investigate the correlation between neurological deficits and structural anomalies, which dominate the clinical presentation in children with spina bifida, and renal cortical function using Tc99m-labeled DMSA (Dimercaptosuccinic acid) scintigraphy.
Methodology206 pediatric cases (100M, 106 F; age 0-18 years, mean:7.2) with SB who underwent DMSA scintigraphy for recurrent urinary tract infections (RUI) were included in this retrospective study. In 78 cases SPECT/CT (Single Photon Emission Computed Tomography) was used for demarcation of the anatomical structures. clinical findings, renal functions, structural and neurological anomalies of the patients, the history of urinary tract surgery, the frequence of RUI and vesicoureteral reflux (VUR), the frequency of Clean Intermittent Catheterization (CIC), prophylactic antibiotic use, hypertension, proteinuria, ultrasound findings and serum urea-creatinine levels. The patients were grouped according to the severity of neurological deficits. DMSA scintigraphy findings were compared with the clinical data and the severity of ND.
FindingsAmong 206 patients with SB, 126 had severe neurogenic dysfunction (ND), 41 had moderate ND, and 39 had no ND. A total of 117 children presented with complicated meningomyelocele at birth and underwent surgical repair. Ventriculoperitoneal shunt implantation was performed in 104 cases, while 2 had cervical SB and 1 had thoracolumbar SB. Neurogenic bladder was identified in 199 patients. Clean intermittent catheterization (CIC) was performed by 156 patients, and 134 received prophylactic antibiotic therapy. Unilateral renal agenesis was detected in 8 cases, and horseshoe kidney anomaly in 5 cases. When kidneys were evaluated separately, among a total of 404 renal units, stage ≥3 hydronephrosis was observed in 38 units, and stage ≥2 VUR was detected in 73 units on voiding cystourethrograms (VCUG). Ultrasound revealed structural renal dysmorphism in 176 renal units. The incidence of ≥stage 2 VUR on VCUG was significantly higher in children with dysmorphic kidneys compared to those without dysmorphism (26% vs. 13%, p = 0.01). A significant positive correlation was found between structural renal dysmorphism and cortical defects on DMSA scintigraphy. Cortical defects were detected in 74% of patients with dysmorphic kidneys, compared with 21% of those without ( p= 0.001). DMSA scans showed cortical damage in 66% (44 renal units) with ≥stage 3 VUR and in 38% (128 renal units) with stage ≤2 VUR on VCUG. Overall, cortical defects consistent with renal scarring were observed in 174 renal units on DMSA scintigraphy. The presence of renal cortical damage was significantly associated with the severity of ND. The rate of cortical damage was 52% in children with severe ND, 39% in those with moderate ND, and 28% in patients without ND (p = 0.008). In 78 children who underwent SPECT/CT imaging, planar DMSA images from 11 children were re-evaluated using anatomical correlation data. CT was performed as a low-dose anatomical correction procedure.
ConclusionThis study demonstrated that renal scarring and cortical loss are common in children with spina bifida. Renal dysmorphism, vesicoureteral reflux, and neurogenic bladder contribute significantly to renal parenchymal injury. Furthermore, the severity of neurogenic dysfunction correlates with the extent of cortical loss. DMSA scintigraphy remains a reliable, non-invasive modality for the assessment of renal cortical function in children with SB.