Asymptomatic Renal Stones—to Treat or Not to Treat
Purpose of Review
There are no current guidelines on the optimal management of asymptomatic renal stones. This review summarizes the current literature, focusing on more recent studies that have been done to grow the body of evidence on this topic.
Recent studies have found that stone size is a significant predictor of need for future surgical intervention, with > 7 mm for pediatric population and > 4 mm for residual fragments after both PNL and ureteroscopy (URS). The role of URS has been better defined with a recent RCT concluding that URS and SWL had comparable outcomes for an asymptomatic lower pole stone < 1 cm.
The treatment decision for asymptomatic renal stones should take into consideration a variety of relevant patient and stone factors; however, ultimately, a shared decision-making approach should be used. In the properly counseled patient, active surveillance or prophylactic surgical intervention may be appropriate.
KeywordsRenal stones Treatment Asymptomatic Observation Residual fragments
Compliance with Ethical Standards
Conflict of Interest
Necole M. Streeper declares no potential conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by the author.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 4.• Dropkin BM, Moses RA, Devang S, Pais VM Jr. The natural history of nonobstructing asymptomatic renal stones managed with active surveillance. J Urol. 2015;193:1265–9. Retrospective review of 110 patients with 160 renal stones, 72% remained asymptomatic with average follow up of over 3 years CrossRefPubMedGoogle Scholar
- 10.• Telli O, Hamidi N, Bagci U, Demirbas A, Hascicek AM, Soygur T, et al. What happens to asymptomatic lower pole kidney stones smaller than 10 mm in children during watchful waiting? Pediatr Nephrol. 2017;32(5):853–7. Retrospective review of 242 pediatric patients with asymptomatic lower pole renal stones < 10 mm in size, estimated stone progression rate of 61.2%. Stone size > 7mm, renal anomalies, and cystine or struvite composition were statistically significant predictors of need for future surgical intervention CrossRefPubMedGoogle Scholar
- 11.• Dos Santos J, Lopes RI, Veloso AO, Harvey E, Farhat WA, Papanikolaou F. Outcome analysis of asymptomatic lower pole stones in children. J Urol. 2016;195:1289–93. Retrospective review of 224 pediatric patients, reported a 53.6% rate of spontaneously passed stones, 25% remained asymptomatic and 21.4% ultimately required surgical intervention CrossRefPubMedGoogle Scholar
- 21.Keely FX Jr, Tilling K, Elves A, Menezes P, Wills M, Rao N, et al. Preliminary results of a randomized controlled trail of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones. BJU Int 2001; 87 (1): 1–8.Google Scholar
- 22.•• Sener NC, Bas O, Sener E, Zengin K, Ozturk U, Altunkol A, et al. Asymptomatic lower pole small renal stones: shock wave lithotripsy, flexible ureteroscopy or observation? A prospective randomized trail. Urology. 2015;85:33–7. RCT randomizing patients with asymptomatic single lower pole stones <1cm to ureteroscopy, shockwave lithotripsy, and observation. The stone free rate for URS was 92% and 90% for SWL after an average of 1.48±0.65 sessions. Observation group had a 12% rate of stone progression over 2 year follow-up CrossRefPubMedGoogle Scholar
- 23.• Olvera-Posada D, Ali SN, Dion M, Alenezi H, Denstedt JD, Razvi H. Natural history of residual fragments after percutaneous nephrolithotomy: evaluation of factors related to clinical events and intervention. Urology. 2016;97:46–50. Retrospective review of 44 out of 781 patients with residual fragments after PNL. Residual fragments > 4mm, and struvite or apatite composition, were associated with higher likelihood to require surgical intervention during mean follow up of 57.9 months CrossRefPubMedGoogle Scholar
- 24.• Chew BH, Brotherhood HL, Sur RL, Wang AQ, Knudsen BE, Yong C, et al. Natural history, complications, and re-intervention rates of asymptomatic residual stone fragments after ureteroscopy: a report from the EDGE Research Consortium. J Urol. 2016;195:982–6. A multicenter retrospective review of the natural history of asymptomatic residual fragments following ureteroscopy, including 232 patients. They reported that 56% of patients remained asymptomatic with a mean follow up of 16.8 months. 29% of patients required a secondary procedure. In addition, they concluded that residual fragment size > 4mm after ureteroscopy was associated with significantly higher rate of stone growth and need for re-intervention CrossRefPubMedGoogle Scholar