Outcomes of long‐term follow‐up of patients with conservative management of asymptomatic renal calculi

Abstract

Study Type – Prognosis (cohort) Level of Evidence 4 What’s known on the subject? and What does the study add? Several small series studies have looked at the natural history of asymptomatic renal stones. The number of subjects in these studies ranged from 24 to 300 and duration of follow‐up ranged from 19.4 to 52.3 months. The reported incidences of spontaneous passage, progression and intervention were 3 to 15%, 33 to 77% and 7 to 26%. This study reports on the natural history of asymptomatic stones with an average size of 5.7 mm which were smaller in size than those reviewed in other series. The findings were that the incidence of spontaneous passage was higher than in other series at 20% and that the incidence of intervention was low at 7.1%. This study found that stones that were less than 5 mm in diameter were significantly more likely to pass spontaneously than stones that were larger and there were no other significant differences in the outcomes when stratified according to the initial size and location of stones. OBJECTIVE • To evaluate the long‐term outcomes of patients undergoing observation of asymptomatic renal calculi. PATIENTS AND METHODS • This is a retrospective review of 50 patients with 85 stones undergoing observation with annual imaging from January 2005 to December 2009. • The incidences of spontaneous stone passage, stone progression and intervention were evaluated and assessed for statistical difference according to initial size and location of stone. • Percutaneous nephrolithotomy, shock wave lithotripsy and ureteroscopy were performed when patients developed complications from the stones. RESULTS • Patients were followed up for a mean of 46 months. Sixteen percent had bilateral stones and 38% had multiple stones. • The average stone size was 5.7 mm and 31%, 26% and 43% of the stones were located in the upper, middle and lower pole respectively. • Overall incidences of spontaneous passage, progression and intervention were 20%, 45.9% and 7.1% respectively. • Stones measuring 5 mm or less were significantly more likely to pass (P= 0.006). • There was no significant difference in the incidence of passage according to the initial location of the stone (P= 0.092). There was no significant difference in intervention or progression according to the initial size (P= 0.477 and 0.282 respectively) or location of stone (P= 0.068 and 0.787 respectively). CONCLUSIONS • Patients with asymptomatic renal stones may be managed conservatively in view of low risk of intervention (7.1%). • Annual imaging should be performed as half of these stones will progress in size.

When (and how) to surgically treat asymptomatic renal stones

“…A retrospective study of 50 patients with smaller asymptomatic stones (mean size 5.7 mm in a total of 85 stones) reported rates of Key points ■ The prevalence of asymptomatic stones identified in screened populations is 8-10%, and is likely to grow with increased CT utilization ■ Outcomes of asymptomatic stones <10 mm in diamater include a symptomatic stone event (13-32%), spontaneous passage (13-20%), size increase (30-46%) and intervention (7-26%) ■ Asymptomatic stones located in the renal pelvis and >15 mm are at high risk of progression, defined as increase in size, symptomatic stone event, or need for intervention ■ Shockwave lithotripsy does not improve stone-free rates or quality of life compared to observation for asymptomatic calyceal stones <15 mm ■ Percutaneous nephrolithotomy improves stone-free rates compared to shockwave lithotriposy and observation for asymptomatic lower pole stones ■ Randomized trials are needed to define the role of ureteroscopy in the management of asymptomatic renal stones spontaneous passage, size increase, and intervention of 20%, 46%, and 7%, respectively. 12 A single prospective study has been performed in patients with asymptomatic lower pole stones, who were followed with observation for a mean of 52.3 months. 13 24 patients (27 affected renal units) with a mean stone size of 8.8 mm were followed prospectively, 12.5% of whom developed pain, and 12.5% required intervention.…”

Focused Ultrasonic Propulsion of Kidney Stones: Review and Update of Preclinical Technology

“…With long-term follow-up, *20% of asymptomatic stones with mean size <6 mm passed spontaneously, while 45% remained within the kidney but enlarged, and 7% ultimately required intervention. 7 Most small asymptomatic stones could be managed conservatively, but some patients might desire a noninvasive method to facilitate stone passage due to personal preference or occupational requirements (e.g., pilots). A provoked, but controlled stone event could avoid the unpredictability of stone passage while on observation.…”

“…[1][2][3][4][5][6] Small asymptomatic stones that are followed rather than treated may also ultimately require intervention. 7 Likewise, patients presenting with an acute obstructing stone and signs of infection, hemodynamic instability, renal insufficiency, or intractable nausea or pain, may require an urgent procedure to provide drainage of the obstructed kidney. 8 Currently, the only options to relieve obstruction are surgical.…”

Kontroverse Unterkelchstein

“…In einer in 2011 publizierten Studie haben Koh et al [22] Zusammenfassend kann trotz der überschaubaren und teilweise widersprüchlichen Datenlage Patienten mit asymptomatischen Unterkelchsteinen ein abwartendes Vorgehen bis zu einer Steingröße von ca. 1 cm angeboten werden und mit dem gut informierten Patienten gegenüber den Risiken und Nutzen einer Intervention abgewogen werden [32].…”