Presented by: Natalia L. Arias Villela MD
Chesapeake Urology

Introduction

Retrograde renal access percutaneous nephrolithotomy technique was first described by Lawson in 1983. However, the technique was not widely adopted in the urology community. RetroPerc® is a new retrograde access device that uses direct endoscopic visualization with a flexible ureteroscope. RetroPerc® may be an alternative for the urologist who is not comfortable obtaining antegrade access to perform a percutaneous nephrolithotomy.

Materials

Procedures were performed by a single surgeon in a freestanding ambulatory surgical center. RetroPerc® was used in a total of 8 cases. Patient ages ranged from 53 to 74 years old, BMIs ranged from 22.1 to 33.7, and stone burden ranged from 14 to 40mm with primary localization in the renal pelvis or the lower pole. C-arm fluoroscopy was used to track the puncture wire from the selected calix to its exit site in the skin.

Results

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Retrograde access was successful in 6 of the 8 patients. Retrograde punctures were performed in inter-pole or lower pole calyces. Puncture-to-skin exit times ranged from 35 to 183 seconds. Factors that led to unsuccessful punctures included: puncture wire hitting a rib, puncture wire that tracked caudally and became unsuitable for tract dilation, and unidentifiable puncture wire skin exit site. No complications related to the renal access were noted.

Conclusion

RetroPerc® is a viable and safe alternative for retrograde renal access. Both inter-pole and lower pole calyces are suitable for retrograde punctures sites. Unsuccessful retrograde puncture attempts were likely related to the learning curve associated with a new technique and not with inherent limitations of the device or method. Appropriate patient selection and surgical planning are key for successful implementation of RetroPerc® when obtaining retrograde access. Further research is needed to identify cases where retrograde access may be more advantageous than the traditional antegrade approach.

Funding

None

Lead Authors

Andy J. Martinez Morales, MD
Chesapeake Urology

Co-Authors

Max R. Drescher, MD
Chesapeake Urology

Julio G. Davalos, MD
Chesapeake Urology