"Microperc" micropercutaneous nephrolithotomy: a review of the literature

Microperc with Self-Assembled Fr 4.85 Visual Needle and Ureteral Access Sheath

BACKGROUND

Micropercutaneous nephrolithotomy (microperc) is the least invasive among percutaneous nephrolithotripsy (PCNL) procedures. Although microperc has a high stone-free rate and certain advantages over other methods, modifications may be needed to improve the technique. We describe our experience performing microperc using a self-assembled visual needle and ureteral access sheath (UAS).

METHODS

Between June 2016 and April 2019, the data of 30 patients with kidney stones undergoing microperc with our self-assembled 4.8 Fr visual needle combined with a UAS was retrospectively analyzed. Patients were placed in an obilique spine lithotomy position.

RESULTS

Two cases were excluded: one due to conversion to mini PCNL and the other required flexible ureteroscopy during microperc. The remaining 28 cases included 18 men and 10 women, age 38.4 ± 7.5 years, stone size 1.7 ± 0.4 cm, and stone density on CT 969 ± 233 HU. Operative time was 47 ± 9.9 minutes, visual analogue scale score of tract pain on postoperative day 1 was 2.5 ± 1.0, hemoglobin decrease was 6.4 ± 1.0 g/L, and hospital stay was 3.1 ± 0.8 days. There was 1 case of fever and urinary infection, 2 cases of hematuria, and 1 case of flank pain. All symptoms resolved after conservative or antibiotic treatment. On postoperative day 1, 12 (42.9%) caseswere stone-free. The stone-free rates at postoperative month 1 and 3 were 92.9% (26/28) and 100% (28/28), respectively.

CONCLUSIONS

Our self-assembled visual needle and UAS instrument is effective for microperc. Use of the UAS may improve the operative outcome.

Micropercutaneous endopyelotomy for the treatment of secondary ureteropelvic junction obstruction in children

INTRODUCTION

The management of recurrent pyeloureteral junction obstruction (PUJO) is controversial, as there is no suitable technique for its correction. Percutaneous endopyelotomy shows better results in recurrent PUJO compared to primary PUJO. Micro-percutaneous approaches reduce damage to renal parenchyma and facilitate access to renal pelvis.

OBJETIVE

To present our experience in the use of this minimally invasive technique for the treatment of recurrent PUJO.

STUDY DESIGN

A retrospective study was performed collecting data of patients with recurrent PUJO treated in our hospital using the percutaneous approach between July 2014 and January 2018. Micropercutaneous access was performed in all patients. In Valdivia position, a 5 or 6 mm high-pressure ballon is placed in the renal pelvis under cystoscopic and fluoroscopic guidance. The 4.8 or 8 Fr microperc puncture needle is placed into the pelvicalyceal system. Endopyelotomy is performed with a laser fiber or monopolar hook on a high-pressure balloon. To improve the exposure of the cutting area, the high-pressure balloon is placed at the pyeloureteral junction. Double J stent is left for weeks.

RESULTS

The ages of the patients were 4, 8 and 18 months, and 2 and 4 years. All patients had previously undergone pyeloplasty due to pyeloureteral junction obstruction. Operative time was 50 ± 21 min. Hospital stay after surgery was 24 h and hematuria disappeared within the 24 postoperative hours.

DISCUSSION

The number of patients with recurrent PUJO is small, making it difficult to establish a standard surgical approach for failed pyeloplasty. Redo pyeloplasty is considered the gold standard by some authors but alternative methods, such as endourological techniques, may also have a role in the treatment of failed pyeloplasty. The percutaneous approach has shown very good results in this treatment and the miniaturization of percutaneous surgery has improved with the micropercutaneus access. We consider micropercutaneous approach helped with a high pressure balloon in the pyeloureteral junction is an alternative and minimally invasive technique that has shown good results in our small cases series. However, we must take into account the limitation of the study considering the low number of patients. We need prospective studies to support our results.

CONCLUSION

Micropercutaneous endopyelotomy is a fairly effective technique to treat recurrent UPJO after failed pyeloplasty in children. In our experience, it reduces kidney damage without increasing complications.