Retrograde intrarenal surgery in the management of pediatric cystine stones

OBJECTIVE

To investigate the efficacy and safety of retrograde intrarenal surgery (RIRS) in the treatment of pediatric cystine stones.

STUDY DESIGN

Data of the pediatric patients who underwent RIRS for kidney stones were retrospectively evaluated. A total of 14 children with cystine stones managed with RIRS were identified. In addition to the patient demographics and stone characteristics, all retrospectively obtained operative data were evaluated and discussed in detail, with an emphasis on the success and complication rates.

RESULTS

Mean age of the 14 cases was 10.9 ± 2.2 years (range: 7-15). Mean stone size was 13.6 ± 2.4 mm (range: 10-18) (Summary table). Of these stones, four were located in the renal pelvis, three were in the lower, three were in the middle and the remaining four were located in upper calyx. Ureteral access sheath was used in 12 (85.7%) patients. The double-J ureteral stent was placed pre-operatively in one case and was inserted postoperatively in 12 cases. Mean operation time was 38.2 ± 7.2 min (range: 30-50). Complications were observed in two cases: mild ureteral laceration in the first and fever on the second postoperative day in the second patient. All of the patients were stone free on sonographic evaluation at the 4-week follow-up evaluation. Although potassium citrate treatment was initiated in 11 patients, tiopronin treatment was initiated in four patients for recurrence prophylaxis during long-term follow-up. During a mean follow-up period of 25.7 ± 5.2 months, stone recurrence was noted in one patient.

DISCUSSION

Treatment of patients with cystine stones is challenging, due to high risk of rapid recurrence in the presence of residual fragments. Besides allowing complete stone clearance in all cases in the current series, RIRS is a highly reproducible method that can be safely performed, even in recurrences. The major limitations of the current study were low number of patients and short follow-up period.

CONCLUSION

The results clearly indicated that RIRS is a safe treatment modality in the management of pediatric cystine stones.

The effects of four different suture materials on penile tissue of rats

Several types of suture materials are being used for the correction of penile curvature and this study was designed to compare histopathological changes on penile tissue among different suture materials. A total of 30 male Sprague-Dawley rats were divided into five groups and right cavernosal body was sutured with 5/0 sutures (ETB: polyethylene terephthalate; PRL: polypropylene; VCR: polyglactine; and PDS: polydioxanone). An identical needle (3/8-13 mm cutting) was passed through the cavernosal bodies in the sham group (SHAM). After 3 weeks, all rats were killed and penile tissues were examined to assess the level (0-3) of inflammation, granuloma formation and fibrosis. There was a statistically significant difference among five groups regarding inflammation, granuloma formation and fibrosis levels (P<0.01 for all). The histological changes in the PRL group were not different from the SHAM group. Although the levels of granulation and fibrosis in the PDS group were also similar to the SHAM group, inflammation level was significantly higher. The inflammation, granulation and fibrosis levels were the highest in the ETB group. VCR caused similar levels of granulation and fibrosis to ETB. In conclusion, PRL suture is associated with the least histopathological change in the penile tissue. PDS can theoretically be a reasonable alternative to PRL as it causes similar levels of granulation and fibrosis.