Der 1 cm UKG-Stein: ESWL, URS oder Mini-PCNL? Leitlinien versus Realität

Zusammenfassung

Harnsteine der oberen, ableitenden Harnwege erfüllen durch ihre hohe Inzidenz und Prävalenz sowie auch in gesundheitspolitisch-finanzieller Hinsicht die Kriterien für eine Volkskrankheit. Ein erheblicher Anteil der neu diagnostizierten Nierensteine sind Unterpolsteine, betreffen also die untere Kelchgruppe des Nierenbeckenkelchsystems. Diese werden häufig als Zufallsbefund diagnostiziert, also als Zufallsbefund im Rahmen von Ultraschall- oder CT-Diagnostik aus anderen Gründen, oder als „Zweit-Steine“ bei der diagnostischen Aufarbeitung von symptomatischen Harnsteinen an anderen Lokalisationen. Eine weitere, quantitativ bedeutende Gruppe wird durch Rest-Desintegrate nach extrakorporaler Stoßwellenlithotripsie (ESWL) oder endoskopischer Steintherapie. Diese zufällig entdeckten Unterpolsteine zeichnen sich oft durch ihre geringe Größe und die fehlende Symptomatik aus. Nun liegt es nahe, dass ein Teil dieser kleinen, asymptomatischen Unterpolsteine nicht immer klein und asymptomatisch bleibt, und dass eine Therapie mit zunehmender Größe eher aufwendiger wird.

Interessanterweise finden sich im Verlauf der letzten 20 Jahre erstaunlich wenig publizierte Studien auf hohem Evidenzniveau, die imstande sind, die Fragestellung dieser Übersichtsarbeit schlüssig und reproduzierbar zu beantworten.

Kleine, asymptomatische Steine können beobachtet werden. Symptomatische und schnell wachsende sollten behandelt werden. Valide Risikofaktoren, die die Identifikation von Subgruppen erlauben, die man prophylaktisch schon im asymptomatischen Stadium behandeln sollte, fehlen nach wie vor.

Bei der aktiven Therapie gilt genau wie vor 10 oder 20 Jahren der Grundsatz: Steinfreiheit in einer Therapiesitzung wird mit einer erhöhten Komplikationsrate bezahlt, wobei zunehmende Miniaturisierung in der Endourologie (retrograd und perkutan) sowie die immer effektiver werdende Laser-Desintegration dieses Grundprinzip mehr und mehr zugunsten von flexibler URS und (mini, micro) PCNL verschieben. Der Indikationsbereich für die ESWL wird ohne Zweifel immer kleiner, dies gilt auch für Unterpolsteine. Die Ergebnisse einer laufenden, allerdings mit Rekrutierungsproblemen kämpfenden, prospektiv randomisierten Studie zum Vergleich der verschiedenen Behandlungsmodalitäten stehen noch aus.

Abstract

Urinary stones of the upper urinary tract can be considered a widespread public health concern due to their high incidence and prevalence and their health policy-related and financial implications. A significant proportion of newly diagnosed kidney stones are lower-pole stones, i.e., stones affecting the lower calyx group of the renal pelvicalyceal system. These are often diagnosed by chance, i.e., as incidental findings during ultrasound or CT scans performed for other reasons, or as “secondary stones” detected during the diagnostic work-up of symptomatic urinary stones in other locations. Residual disintegrates after extracorporeal shock-wave lithotripsy (ESWL) or endoscopic stone therapy constitute a further, quantitatively significant group. These incidentally discovered lower-pole stones are often characterised by their small size and lack of symptoms. It stands to reason that some of these small, asymptomatic lower-pole stones do not always remain small and asymptomatic, and that treatment tends to become more complex with increasing size.

There has been an astonishing lack of published studies with a high level of evidence over the last 20 years to provide a conclusive and reproducible answer to the question posed in this review.

Small, asymptomatic stones can be monitored. Symptomatic and rapidly growing stones should be treated. There is a lack of valid risk factors allowing an identification of subgroups that should be treated prophylactically at the asymptomatic stage.

In active therapy, a 10-to-20-year-old principle still holds true today: a high stone-free rate in one therapy session is offset by an increased complication rate, with increasing miniaturisation in endourology (retrograde and percutaneous) and increasingly effective laser disintegration shifting this basic principle more and more in favour of flexible URS and (mini, micro) PCNL. The range of indications for ESWL is undoubtedly becoming smaller, and this also applies to lower-pole stones. The results of an ongoing prospective randomised study comparing the different treatment modalities, albeit with recruitment difficulties, are still pending.

Schlüsselwörter

Nierenkelchstein - Unterpol - Beobachtung - Therapie

Keywords

lower pole - observation - therapy - nephrolithiasis

Publication History

Received: 07 March 2024

Accepted: 13 March 2024

Article published online:
23 April 2024

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