Cystoscopic and DMSA findings in relation to types of reflux demonstrated on percutaneous direct radionuclide cystography in children

Types of Parenchymal Changes Diagnosed on DMSA Scans of Kidneys Affected by Different Grades of Vesicoureteral Reflux

Background

Renal parenchymal damage and scarring usually is associated with urinary tract infection (UTI), whereas the impact of vesicoureteral reflux (VUR) on the kidneys is unclear. We aimed to compare kidneys with all grades of VUR (grades Io-V) and those without VUR by using direct radionuclide cystography, voiding cystourethrography, and findings from ^99mTc-DMSA scintigraphy (DMSA scan).

Material/Methods

The present analysis included 253 renal ureteral units (RUU) from 129 children with VUR and recurrent UTI and children with a single febrile UTI associated with abnormal ultrasonographic findings. The 6 grades of VUR (Io, I, II, III, IV, and V) and 35 RUUs without VUR were divided into 4 groups: 1. Non-dilated VUR (grades Io-II); 2. Mildly dilated VUR (grade III); 3. Dilated VUR (grades IV–V); and 4. The control group.

Results

DMSA scanning showed significant differences between the groups with non-dilated VUR, grade III VUR, grades IV–V VUR, and the control group in kidney width (χ²=30.5; P<0.001); position and shape (χ²=30.6; P<0.001); intensity of activity (χ²=38.1; P<0.001); distribution of activity (χ²=34.5; P<0.001); and existence of scars (χ²=16; P<0.001). The probability of abnormalities on DMSA scans increased with the VUR grade. However, inside the groups of dilated and non-dilated VUR we found no significant statistical differences between those characteristics.

Conclusions

Our results indicate that kidneys without VUR or with non-dilated lateral VUR and dilated VUR on the contralateral side represent 2 different categories of parenchymal changes.

Evaluation of cyclic direct radionuclide cystography findings with DMSA scintigraphy results in children with a prior diagnosis of vesicoureteral reflux

OBJECTIVES

Direct radionuclide cystography (DRC) with cyclic imaging is a sensitive method used for the detection of vesicoureteral reflux (VUR). Radionuclide cystography is generally recommended for follow-up evaluation of VUR. The aim of this study was to evaluate cyclic DRC with DMSA scan results during the follow-up period in children with a prior diagnosis of VUR.

PATIENTS AND METHODS

DRC findings of 85 children with VUR were evaluated together with DMSA findings during follow-up. VUR grade was classified anatomically as grades I, II, and III reflux. Reflux grades of II and III were regarded as high-grade reflux. Reflux was also graded functionally as transient and continuous on the basis of the presence of reflux on either filling or voiding phases (transient) or both phases (continuous) of at least one cycle.

RESULTS

Among 85 children, 32 (38%) exhibited reflux. In five patients, reflux was observed on both sides, and a total of 37 refluxing units (RUs) were evaluated. According to the highest grade attained in either cycle, 31 (84%) units had grade II, five had grade I and one had grade III reflux. Reflux was continuous in 23 (62%) and transient in 14 (38%) RUs. The incidence of an abnormal scan result was higher in continuous reflux group (78%) than in high-grade anatomic reflux group (59%). The addition of a second cycle resulted in the diagnosis of continuous reflux in six (26%) more RUs. DMSA scan findings correlated significantly with functional reflux classification (P<0.05), but not with anatomic reflux classification (P>0.05).

CONCLUSION

Functional classification of VUR into continuous and transient reflux resulted in higher correlation with DMSA scan findings compared with anatomic reflux grading in follow-up patients with VUR. Cyclic imaging contributed to continuous reflux diagnosis. The significance of functional information obtained from cyclic DRC in initial diagnostic workup, management, and follow-up of children with urinary tract infection needs to be determined with further studies.

Correction of vesicoureteral reflux: where do we stand?

PURPOSE OF REVIEW

Newer techniques of molecular biology allow us to gain a better understanding of the molecular mechanism of primary urinary reflux. In recent years, diagnostic tools and treatment options for vesicoureteric reflux have dramatically changed. In this review, we want to focus on genetics, molecular biology, histology, clinical findings, diagnostic tools and newer surgical techniques for the treatment of vesicoureteric reflux published between 2003 and March 2004.

RECENT FINDINGS

Recent findings have demonstrated that the renin-angiotensin-aldosterone system does not seem to be responsible for the development of primary vesicoureteric reflux. Echo-enhanced ultrasound with contrast medium in the bladder, performed by an experienced investigator, could replace the voiding cystourethrogram in follow-up studies of patients treated conservatively for vesicoureteric reflux. The sensitivity and specificity of ultrasound is in the range of 70-100% in some studies compared with the standard voiding cystourethrogram. Endoscopic treatment of vesicoureteric reflux using Defux or Macroplastique has gained more and more popularity, with success rates ranging between 60 and 86%. The surgery is performed on an outpatient basis with minimal morbidity. Long-term results after open operative techniques have demonstrated cure of reflux in over 95% of cases.

SUMMARY

In the coming years, echo-enhanced ultrasound may replace the standard voiding cystourethrogram during follow-up and it may be used as an initial test in females with normal voiding patterns. Endoscopic reflux correction must be judged on the re-treatment rates and long-term success.