The Zeiss-loop stone extraction: minimal invasive and effective or obsolete?

Through the introduction of ureterorenoscopy (URS) and extracorporal shock wave lithotripsy (ESWL) into stone treatment, the Zeiss-loop procedure has lost more and more its importance. Current guidelines recommend on the level of an expert-opinion, that stone extraction without endoscopic-visual control should not be performed anymore. Nevertheless, stone extraction using the Zeiss-loop is still being performed in our clinic and therefore we wanted to determine its position in stone treatment in the age of URS and ESWL.

The data of 253 patients with ureter stones, who were treated with the Zeiss-loop were evaluated. The loop is always pulled through completely under radiological control.

In 221 cases, the concrement was located in the distal ureter. All concrements have been maximally 10 mm in size. Independently of size and position, in 219 patients the loop extraction resulted in a complete stone removal. Complication rates are low. No complete tear-off of the ureter occurred. The overall success rates of loop extraction were superior to those of ESWL in ureter stones but worse than URS. Referring to distal stones, success rates are similar, but stones treated by URS have been bigger.

Therefore, in our opinion, immediate stone extraction under fluoroscopic control with the Zeiss-loop, is still a possible treatment alternative for small distal stones (<10 mm). Being aware of these first "new" data of an old procedure, the Zeiss-loop will still play a role in endoscopic stone treatment in our department and should not be completely abandoned due to its bad reputation.