Removal of Asymptomatic Kidney Stones and Incidence of Relapse: A Systematic Review

doi:10.21203/rs.3.rs-2962992/v1

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Removal of Asymptomatic Kidney Stones and Incidence of Relapse: A Systematic Review

https://doi.org/10.21203/rs.3.rs-2962992/v1

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Introduction: Ureterolithiasis is one of the most prevalent diseases in the world, among the surgical treatments, ureteroscopy and percutaneous nephrolithotomy may be chosen depending on the size of the stone. The aim of this study is to define whether endoscopic treatment for asymptomatic kidney stones reduces the cumulative relapse in patients undergoing ureteroscopy for symptomatic kidney stones.

Methods: MEDLINE, Embase, Google Scholar, Web of Science search retrieved 1182 articles, 2 of them were selected for meta-analysis (Figure 1).

Results: This meta-analysis shows (Figure 2) that the difference in the cumulative relapse in the first 18 months is not statistically significant (OR 0.10, CI 0.01-1.45).

Conclusion: Even though there seems to be a tendency of lower relapse in surgery for asymptomatic stones, there is a lack of evidence to support simultaneous RIRS for asymptomatic renal stones in patients with ureteroscopic symptomatic stone removal.

kidney stones

asymptomatic

retrograde intrarenal surgery

It is well known that ureterolithiasis is one of the most prevalent diseases in the world, being responsible for more than 2 million office visits and 200,000 hospital admissions in the United States each year.^[1] The prevalence of asymptomatic renal stones in the population is estimated at 8%. When symptomatic, it is usually an indication of surgery, according to type, size, and other characteristics of the stones. The risk of a symptomatic episode or need for intervention in patients with asymptomatic renal stones seems to be close to 50% in five years.^{[1, 2, 3]}

The surgical management of symptomatic kidney stones is warranted if they have more than 1 cm. Retrograde intrarenal surgery (RIRS) is the preferred option for stones between 1 and 2 cm, and percutaneous nephrolithotomy (PCNL) is used for bigger stones or if there is failure of medical treatment.^{[4, 5]}

However, when a patient has both symptomatic and asymptomatic stones, the management of the asymptomatic stones is not clear. On one hand, the American Urological Association Guideline of 2016 leaves the choice between treatment and active surveillance to the physician and the patient.^[2] And the European Association of Urology Guideline of 2022, leaved the question unanswered, but for specific situations as stone growth, obstruction, associated infection, and acute and/or chronic pain active treatment is warranted.^[3]

Most studies involving intervention in asymptomatic stones are retrospective studies and thus far, support observation.^{[6, 7]} One of the few prospective studies cited in the most recent guidelines favoring active surveillance over shock-wave lithotripsy for asymptomatic stones.^[8] The current void of objective evidence in the subject to form strong recommendations is such that the debate was recently evoked in the 2021 dueling editorial comments by experts.^{[9, 10]}

The aim of this systematic review with meta-analysis is to verify if retrograde intrarenal surgery is an appropriate option to manage asymptomatic renal stones.

This study is registered at PROSPERO (CRD42022376590). The population is patients undergoing retrograde intrarenal surgery for treatment of symptomatic kidney stones. In this population we will compare the simultaneous treatment of asymptomatic kidney stones versus the treatment only of the symptomatic stones. The primary outcome is the cumulative incidence of relapse, without time constrains.

MEDLINE, Embase, Google Scholar, Web of Science were searched and a total of 1182 articles were identified. The search strategy included terms related to the intervention (retrograde intrarenal surgery) and terms related to stone disease. As terms related to intervention, we included: uretero* OR 'renoscopy' OR 'furs' OR 'rirs' OR 'retrograde intrarenal surgery', and as terms related to the disease we included: (lithiasis OR calcul* OR ston* OR nephrolith* OR urolith*) AND asymptomatic.

First, the duplicates (n = 484) were removed using an automated tool, the Endnote online ™ 20. Then, two independent researchers (MB and OB) screened the studies by title and abstract, and disagreements were solved by third (JA). After the screening 15 articles were selected for full text assessment.

Of the 15 articles, six were excluded for not meeting the inclusion criteria, two were review studies and five used different or multiple procedures in the treatment branch. Therefore, the team selected two articles (Lai2015 and Sorensen2021) for evaluation and further meta-analysis (Fig. 1), performing a statistical analysis of the outcomes using Rev Man 5.4 ™.

The selected studies were Sorensen et. al. and Lai et. al. Sorensen et. al. published a multicenter, randomized controlled trial with 73 patients included, 38 in the treatment group and 35 in the control group. Lai et. al. did a retrospective control study with 144 patients included, 72 in the treatment group and 72 in the control group. Table 1 compares the baseline characteristics of included studies.

Table 1 Baseline characteristics of included studies

Cumulative relapse was defined as need for surgery, emergency department visits, or need for medical expulsive therapy. Even though Sorensen et al had a median follow up of 4.1 years, for the sake of this meta-analysis, we considered the cumulative recurrence of relapse within the first 18 months. Lai et al had a follow up of 18.9 and 18.5 months so we included this outcome directly.

The meta-analysis shows (Fig. 2) that the difference in the cumulative relapse in the first 18 months is not statistically significant (OR 0.10, CI 0.01–1.45). Also, the risk of bias assessment can be seen in Fig. 3.

The American Guideline suggests clinician and patient discussion as to whether to intervene in asymptomatic stones, being active surveillance a conditional recommendation with grade C level of evidence. Even though studies referred to in the guideline showed 50% of progression of asymptomatic stones they also concluded that a small percentage of those progressed were required to surgical intervention. However, the active treatment of asymptomatic stones is preferred over active surveillance in the following situations: associated infection, poor access to contemporary medical care and patients with high risk vocations such as airline pilots.^[2]

As for the European Urology Association Guidelines, annual observation was recommended for asymptomatic stones smaller than 10mm. Surgical intervention was suggested for growing asymptomatic stones larger than 5mm.^[3]

Sorensen et al conducted a multicenter randomized controlled trial with five years of follow-up, the asymptomatic stones surgically removed in the treatment group were named secondary stones and were defined a ≤ 6mm, asymptomatic stones located in the contralateral kidney. The intervention group underwent endoscopic removal of primary (symptomatic) and secondary stones simultaneously. The primary outcome was cumulative incidence of relapse in five years (symptoms in the trial side, subsequent surgery in the trial side and growth of an original secondary stone measured with CT scan). Secondary outcomes included surgery duration, emergency visits 2 weeks after surgery and patient-reported stone passage.

The results HR of relapse in the treatment group versus control group equals 0,18 [CI 0,07 − 0,44] (P < 0.001), with the mean time to relapse being 36% longer as well in the treatment group. For the secondary outcomes: the treatment group had a median intervention time of 25.6 minutes added. Emergency visits and patient-reported stone passage were not significantly different between groups. Even though 73 patients were included in this study, only 22 completed the 5 year follow up, 11 in the control and 11 in the treatment group.

As for Lai,2015, the study was designed as a retrospective controlled study. 415 files were reviewed of renal stone treatment between 2009 and 2013. 72 patients who underwent simultaneous RIRS for ipsilateral asymptomatic stones after ureteroscopic symptomatic ureteral stone removal were defined as treatment group. This group was matched to a group of 72 selected patients who underwent ureteroscopic laser lithotripsy alone. Matching criteria were stone side, burden and location, as well as the presence of a pre-placed D-J stent.

The outcomes compared between groups included presence of stone in CT scan 1 month after treatment, pain assessed by visual analogue scale, complication rate, hemoglobin drop, hospital duration and cost of treatment and finally necessity of auxiliary treatment or auxiliary procedure with surgical methods. Results showed a significant decrease in necessity of auxiliary procedures in the treatment group (1.86 vs 1.03, p < 0.001) and that is related to a significant decrease in the medical cost per patient as it was observed in the study.

One limitation in the final analysis is the small number of included studies due to the scarce literature about this subject. Another is the relatively low follow up time of 18 months.

There is a lack of evidence to support simultaneous RIRS for asymptomatic renal stones in patients with ureteroscopic symptomatic stone removal.

No funding source. No conflicts of interest disclosure.

Boyce CJ, Pickhardt PJ, Lawrence EM, Kim DH, Bruce RJ. Prevalence of uroli- thiasis in asymptomatic adults: objective determination using low dose noncontrast computerized tomography. J Urol 2010;183:1017–21.
Assimos D, Krambeck A, Miller NL, et al. Surgical management of stones: American Urological Association/Endourological Society guideline. J Urol 2016;196:1153–69.
Turk C, Knoll T, Petrik A, Sarica K, Straub M, Seitz C. Guidelines on urolithiasis. 2012. p. 1–102. Available at: http://www.uroweb.org/gls/pdf/ 20_Urolithiasis.pdf. EUA.
Sabnis RB, Jagtap J, Mishra S, Desai M. Treating renal calculi 1–2 cm in diameter with minipercutaneous or retrograde intrarenal surgery: a prospective comparative study. BJU Int. 2012;110(8 Pt B):E346–9.
Resorlu B, Unsal A, Ziypak T, Diri A, Atis G, Guven S, et al. Comparison of retrograde intrarenal surgery, shockwave lithotripsy, and percutaneous nephrolithotomy for treatment of medium-sized radiolucent renal stones. World J Urol. 2013;31(6):1581–6
Li S, Quarrier S, Serrell EC, Penniston KL, Nakada SY. Should we treat asymptomatic concurrent contralateral renal stones? A longitudinal analysis. Urolithiasis 2022;50:71–7.
Djang R, Stahl JE, Pais VM Jr. Informing the management of symptomatic nephrolithiasis: Markov decision analysis for the 1 cm renal stone. Urol Pract 2021; 8:495–502.
Keeley FX Jr, Tilling K, Elves A, et al. Preliminary results of a randomized con- trolled trial of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones. BJU Int 2001;87:1
Bhalla RG, Hsi RS. Should asymptomatic renal stones be surgically treated? Pro treatment. J Endourol 2021;35:567–9.
Streeper NM. Should asymptomatic renal stones be surgically treated? Pro- observation. J Endourol 2021;35:570–2.

No competing interests reported.

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Removal of Asymptomatic Kidney Stones and Incidence of Relapse: A Systematic Review

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