S2-Leitlinien zu Diagnostik, Therapie und Metaphylaxe der Urolithiasis

Endoscopically Determined Stone Clearance Predicts Disease Recurrence Within 5 Years After Retrograde Intrarenal Surgery

OBJECTIVE

To assess stone-related events (SREs) requiring retreatment in a series of 100 consecutive patients treated by retrograde intrarenal surgery (RIRS) for renal stones and to evaluate potential risk factors thereof.

PATIENTS AND METHODS

The primary outcome was incidence of SRE (medical or surgical treatment). Secondary outcomes included side of SRE, time to SRE, and late complications. Analysis of potential risk factors included high-risk stone formers (HRSFs), obesity, high stone burden, and lower pole stones. In addition, we evaluated endoscopically determined small residual fragments (SRF) of <1 mm (i.e., fragments too small for retrieval) as an independent risk factor.

RESULTS

Eighty-five of the 99 patients were followed up for a mean of 59 months (31-69), among whom 26 (30.1%) had SRE. Thirty-four of the 85 (40%) patients were HRSFs, 22 of whom experienced SRE (both sides) during follow-up (64.7%, p < 0.001). Eight of the 17 patients (47.1%) with SRF experienced ipsilateral side SRE compared with 13 (19.1%) of the 68 without SRF (p = 0.022, hazard ratio 2.823, 95% confidence interval [95% CI] 1.16, 6.85). Risk for ipsilateral SRE was unaffected by the presence of SRF among HRSFs (p = 0.561). Of low-risk patients with SRF, 33.3% experienced ipsilateral SRE, while those without SRF experienced no ipsilateral SRE (p < 0.001).

CONCLUSION

Endoscopically determined stone clearance predicts disease recurrence within 5 years after RIRS. Even SRF are an important risk factor for future stone-related (ipsilateral) events; therefore, patients with residual fragments of any size should not be labeled "stone free" and endoscopic stone treatment should aim at complete stone clearance.

[Recurrence prevention of kidney stone disease]

In each urolithiasis patient the individual risk for recurrence determines the need for specific medical treatment. Therefore, a brief evaluation of the risk status after stone passage is mandatory to define patients at high risk for recurrence. Only one quarter of all urolithiasis patients are at high risk or suffer from severe metabolic disorders, which both demand further metabolic work-up prior to medical therapy. However, the other three quarters benefit sufficiently from general preventive measures, such as high fluid intake, well-balanced mixed diet and lifestyle changes. This article summarizes the recent recommendations for stone-specific recurrence prevention, discusses the different pharmacological treatment options and sketches the follow-up concept for high risk patients with ongoing medication.