Ultrasound classification of solitary renal cysts in children.

INTRODUCTION: Solitary renal cysts are typically incidentally found in children who have undergone renal ultrasound (US). The main concern is a cystic tumor. There is no US-based grading system for children to guide management. OBJECTIVE: To evaluate a US-based, modified Bosniak grading system in order to differentiate between simple (grade I or II) and complex (grade II or IV) renal cysts and guide management in children. STUDY DESIGN: This was a retrospective (2003-2011) study of 212 children (114 females), age range one day to 17 years (mean 8.4 years), with solitary renal cysts diagnosed by US. Two radiologists, who were independent and blinded to clinical information, graded the cysts using the modified Bosniak classification system. In children with more than one year of follow-up US, the change (>10%) in cyst diameter was evaluated. Inter-observer variability (Kappa) was calculated. RESULTS: Radiologists one and two saw simple renal cysts in 96.2-96.6% (204-205/212) of the children. Ten children had complex renal cysts, as rated by either of the radiologists. There was good inter-observer agreement (kappa = 0.65) for simple versus complex cysts. In 20.2% (18/89) of the children, the cysts increased in size. A definitive diagnosis was obtained in 8.5% (18/212) of the children. A cystic tumor (multilocular cystic nephroma) was found in one child (Figure) with a complex cyst (graded III by both radiologists). DISCUSSION: The use of a modified Bosniak classification system to grade renal cysts was found to have good inter-observer variability (kappa = 0.65) in differentiating between simple and complex renal cysts. Using this classification, few (<4%) renal cysts were classified as complex. Cystic tumors are rare and the only cystic tumor (multilocular cystic nephroma) was classified as complex renal cysts by the two radiologists. Growth of simple, solitary renal cyst is common (20.2%) and, therefore, if not associated with other imaging findings, is not an indication for a cystic tumor. There were limitations inherent in the retrospective nature of the study and because only one child had a cystic tumor. CONCLUSION: The modified Bosniak classification system demonstrated good inter-observer agreement, and identified the single tumor as a complex cyst. The vast majority of solitary renal cysts in children are simple and if asymptomatic, they require no other imaging evaluation. Complex renal cysts are uncommon and should be evaluated with a pre-intravenous and postintravenous contrast CT scan to exclude a tumor.

Radiofrequency sacroiliac joint denervation for sacroiliac syndrome.

BACKGROUND AND OBJECTIVES: Radiofrequency (RF) denervation of the sacroiliac (SI) joint has been advocated for the treatment of sacroiliac syndrome, yet no clinical studies or case series support its use. METHODS: We report the results of a consecutive series of 50 SI joint RF denervations performed in 33 patients with sacroiliac syndrome. All patients underwent diagnostic SI joint injections with local anesthetic before denervation. Changes in visual analog pain scores (VAS), pain diagrams, physical examination (palpation tenderness over the joint, myofascial trigger points overlying the joint, SI joint pain provocation tests, and range of motion of the lumbar spine), and opioid use were assessed pre- and postdenervation. RESULTS: The criteria for successful RF denervation were at least a 50% decrease in VAS for a period of at least 6 months; 36.4% of patients (12 of 33) met these criteria. Failure of denervation correlated with the presence of disability determination and pain on lateral flexion to the affected side. The average duration of pain relief was 12.0 +/- 1.2 months in responders versus 0.9 +/- 0.2 months in nonresponders (P < or = 0.0001). A positive response was associated with an atraumatic inciting event. Successful denervation was associated with a change in the pain diagram and a reduction in the pattern of referred pain, a normalization of SI joint pain provocation tests, and a reduction in the use of opioids. CONCLUSIONS: This study suggests that RF denervation of the SI joint can significantly reduce pain in selected patients with sacroiliac syndrome for a protracted time period. Moreover, certain abnormal physical findings (i.e., SI joint pain provocation tests) revert to normal for the duration of the analgesia.