Results and complications of retrograde approach (URS / RIRS) in pediatric urolithiasis

Stefania Ferretti1, Davide Campobasso2, Tommaso Bocchialini1, Claudia Gatti3, Pietro Granelli1, Michelangelo Larosa4, Paolo Salsi1, Carmine Del Rossi3, Umberto Vittorio Maestroni1, Antonio Frattini4
  • 1 Azienda Ospedaliero‐Universitaria di Parma, S.C. di Urologia (Parma)
  • 2 Ospedale Civile di Guastalla, AUSL di Reggio Emilia, U.O.C. di Urologia (Guastallla)
  • 3 Azienda Ospedaliero‐Universitaria di Parma, S.C. di Chirurgia Pediatrica (Parma)
  • 4 Ospedale Civile di Guastalla, AUSL di Reggio Emilia, U.O.C. di Urologia (Guastalla)

Objective

Pediatric urolithiasis is an endemic problem in developing countries, but the incidence is increasing in industrialized countries as well [1]. The management of pediatric urolithiasis is nowadays increasing in the current urologic practice. Treatment of this disease follows the same surgical procedures as in adults. We report our experience in retrograde treatment (URS / RIRS) of pediatric urolithiasis.

Materials and Methods

We have retrospectively reviewed all the kidney units (URs) which underwent to URS / RIRS at our center from January 2009 to December 2016 up to 16 years of age. The data reported include: lithiasic volume, radiological exposure, operative time, complications according to Clavien classification at 3 months from intervention and stone free rate.

Results

We have performed 47 procedures (30 RIRS and 17 URS) in 40 URs with an average age of 8.46 years (range: 2-16 years).
The URs treated in pre-school age (0-4 yy) were 11 with an average age of 3.72 years; 19 in pre-puberty (5-11yy) with an average age of 8.1 years and 10 in puberty (12-16 yy) with an average age of 14.3 years.
In 22 cases a pre-operative uretheral stent was applied (9 cases with age <4, 8 between 5-11 and 5 between 12-16).
The average lithiasic volume was 1.154 cm2 [2]. The mean operative time was 78.4 ± 41.64 minutes (range: 15-140 min) with a radiological exposure of 24 "± 28" (range: 5 "-1'20").
At the end of the procedure a Double J (DJ) was applied in 25 cases and a Mono J (MJ) in 22 cases.
The stone-free rate after one procedure has been 82.5% (33/40). Seven patients required a second intervention to achieve a complete lithiasic remediation. All of these 7 cases had single or multiple lithiasis with a volume greater than 1.767 cm2. The complications recorded at 90 days from the intervention include a case (2.1%) of migration of a fragment in the urether causing hydronephrosis and renal colics after 49 days to the operation (Clavien 3b) that was treated with URS; 5 cases (10.6%) which required the administration of painkillers during the first 48 hours postoperative (Clavien I); 2 cases of urinary tract infections during hospitalization (4.2%) treated with antibiotic therapy (Clavien II).

Discussions

The miniaturization of the instruments, the increasing use of the retrograde approach to treat voluminous lithiasis in adults associated with the increased incidence of pediatric urolithiasis have led the endourologist to treat more patients in pediatric age.
However, particular attention should be paid to treatment planning in patients under 6 years of age, where, based on our experience and the literature data [3], it is useful to apply a uretheral stent for kidney stones or proximal and mid-lumbar ureteral stones before surgery. In our cases, in only three patients under 6 years of age, no pre-operative DJ stent has been required, since it were two patients with stones located in the distal part of the ureter. In pre-puberty cases (5-11 years), a preoperative DJ has been required in 44%, of which 37.5% were patients under 8 years of age.
Another consideration should be the choice of the type of uretheral stent to be applied at the end of the intervention (DJ versus MJ) to avoid excessive use of painkillers or access to the hospital for intolerance associated to the presence of the stent, bearing in mind the need to submit the patient to an additional anesthesia for DJ removal. In 60% of patients under the age of 5 years we preferred to apply a MJ, leaving a DJ alone in cases requiring a second intervention, where the procedure lasted more than an hour or where there was the presence of lithiasic sand related to the dusting of the stone.

Conclusion

Our experience shows how retrograde access is safe even in the pediatric patient with stone free-rate rates that can be matched with the adult population [4-5].

Reference

1- Sas D. An update on the changing epidemiology and metabolic risk factors in pediatric kidney stone disease. Clin J Am Soc Nephrol 2011;6(8):2062-8
2- Tiselius HG, Andersson A. Stone burden in an average Swedish population of stone formers requiring active stone removal: how can the stone size be estimated in the clinical routine? Eur Urol 2003;4(3):275-81.
3- Elgammal MA, Safwat AS, Elderwy A, El-Azab AS, Abdelkader MS, Hammouda HM. Primary versus secondary ureteroscopy for pediatric ureteral stones. J Pediatr Urol. 2014 Dec;10(6):1193-8.
4- Ishii H, Griffin S, Somani BK. Ureteroscopy for stone disease in the paediatric population: a systematic review. BJU Int. 2015 Jun;115(6):867-73.
5- Ishii H, Griffin S, Somani BK. Flexible ureteroscopy and lasertripsy (FURSL) for paediatric renal calculi: results from a systematic review. J Pediatr Urol. 2014 Dec;10(6):1020-5.

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