Evaluation of Retrograde Intrarenal Surgery Results and Stone-free Rate in Children With Kidney Stones
Condition: Renal Stone; Retrograde Intrarenal Surgery
MeSH terms: Kidney Calculi; Nephrolithiasis; Calculi
Study type: Observational [Patient Registry]

Summary: 
      There is a global increase in the prevalence of urolithiasis in children attributed to
      lifestyle changes, dietary habits, climate changes, childhood obesity, and the wider
      availability of ultrasonography. The rising incidence of the disease with its recurrent
      nature emphasizes the need for minimally invasive therapeutic options. Patients in whom RIRS
      has been performed in the last four years with increasing experience will be presented, and
      complications, stone-free rates, and technical details will be discussed.

      This retrospective Cohort study included children who underwent RIRS. Medical history, serum
      electrolytes, midstream urine culture, urinalysis, serum creatinine, complete blood count,
      and coagulation assessments were performed preoperatively. Ultrasonography (USG) was
      performed three months, 6 months, and 1 year after the procedures to evaluate stone
      recurrence and hydronephrosis. The investigators analyzed the stone-free rate ,complications,
      and the conversion to open procedure
    

Detailed description: 
      There has been a worldwide rise in the prevalence of urolithiasis in children, which is
      linked to changes in lifestyle and dietary habits, climate changes, childhood obesity, and
      the increased availability of ultrasonography (1). In pediatric stone disease, it is crucial
      to evaluate the underlying reasons, which may include metabolic disorders, anatomical
      anomalies, and infection, to avoid higher recurrence of stones after treatment (2). The
      increasing incidence and recurrence of this disease highlights the necessity for minimally
      invasive therapeutic solutions. Retrograde intrarenal surgery (RIRS) is gaining new
      indications owing to advanced laser and endoscopic technology, resulting in a constant rise
      in the number of procedures (3).

      Routine RIRS has been performed in our clinic for the last 15 years with increasing rates.
      Patients in whom RIRS has been performed in the last three years with increasing experience
      will be presented, and complications, stone-free rates, and technical details will be
      discussed.

      This retrospective cohort study included children who underwent RIRS between January 2019 and
      December 2022 at the Ankara Bilkent City Hospital, University of Health Science, Ankara,
      Turkey. The inclusion criteria were pediatric patients with kidney stones who underwent RIRS.
      The exclusion criteria were cases that were converted to open surgery, cases in which RIRS
      could not be performed because of anatomical reasons, and cases in which lower pole stones
      could not be reached with RIRS. The Ethics Committee of the Institution approved this study
      (E2-23-5305). All patient details were identified, and all patients provided written informed
      consent to participate in the study. Medical history, serum electrolytes, midstream urine
      culture, urinalysis, serum creatinine, complete blood count, and coagulation assessments were
      performed preoperatively. Plain abdominal film and ultrasonography/computer tomography scan
      examinations were also performed. Patients with preoperative positive urine culture results
      received a complete course of culture-specific antibiotics before RIRS Prophylactic
      antibiotic treatment with cephazolin was administered to all patients prior to surgery.

      Surgical treatment was indicated when there was an obstruction, infection, failure of
      spontaneous stone passage, or stones larger than 7 mm and in the presence of increasing or
      unremitting colic.

      All RIRS procedures were performed under general anesthesia with direct videoscopic and
      fluoroscopic guidance. All procedures were performed by the same surgeon. Semirigid
      ureteroscopy (4.5 Fr R. Wolf, Knittlingen, Germany) or flexible ureteroscopy (Karl Storz
      FLEX-X, Tuttlingen, Germany) was performed to place an access sheath. The decision to use a
      flexible or semirigid ureteroscope depended on the location of the stones. A flexible
      ureteroscope was used for lower pole stone, wherease a semirigid ureteroscope was preferred
      for renal pelvic or upper pole stones. In our practice, all children undergoing RIRS for
      stone disease received cephazolin. Perioperative antibiotic treatment was continued for a
      week following surgery. If a double J (JJ) stent was inserted, antibiotic prophylaxis was
      continued and ceased after removal of the JJ stent. A manual irrigation pump system was used
      for hydrodilation of the ureter during ureterorenoscopy. If this was not enough to pass the
      ureteroscope, the investigators placed a JJ catheter for passive dilatation. Ureteral active
      coaxial or balloon dilation was not performed. The investigators used isotonic fluid at body
      temperature to avoid hypothermia and hyponatremia during the procedures. The urinary bladder
      was maintained at low pressure with a 14-F suprapubic angiocatheter in all patients. Stones
      were fragmented using a holmium-YAG laser (Litho Quanta System, Italy) and grasped by a stone
      basket when applicable. Contrast injection was performed at the end of the procedures to
      confirm the absence of extravasation and stone-free status. The decision to place a
      postoperative uretral stent was made according to visible mucosal ureteral trauma or edema at
      the end of the procedure. The extracted stone specimens were submitted for stone analysis.
      All patients were discharged if fever was not detected the day after the procedures. Medical
      therapy and dietary planning were provided postoperatively on the basis of the composition of
      the stones. Ultrasonography (USG) was performed three months, six months, and one year after
      the procedures to evaluate stone recurrence and hydronephrosis. The investigators analyzed
      the stone-free rate, complications, and conversion to the open procedure. Statistical
      analysis was performed using the Chi-Square and ANOVA tests, p: 0.05 was considered
      statistically significant.
    

Intervention name(s): Retrograde Intrarenal Surgery
Intervention type(s): Procedure
Intervention description(s): All RIRS procedures were performed under general anesthesia with direct videoscopic and fluoroscopic guidance. The decision to use a flexible or semirigid ureteroscope depended on the location of the Stones. If this was not enough to pass the ureteroscope, we placed a JJ catheter for passive dilatation. Stones were fragmented using a holmium-YAG laser and grasped by a stone basket when applicable. Contrast injection was performed at the end of the procedures to confirm the absence of extravasation and stone-free status. Ultrasonography (USG) was performed three months, six months, and one year after the procedures to evaluate stone recurrence and hydronephrosis.
Other intervention name(s): Lithohtrapsy
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        One hundred and five patients (49 boys and 56 girls) with a median age of 6,66+5,27 years
        (0,25-17,6 years) were treated with RIRS between January 2019 and December 2022. The RIRS
        procedure could not be performed in 15 cases, whereas it could be performed in 90 cases.
      
Keywords: Kidney Stone; Retrograde Intrarenal Surgery; Children; Stone Free Rate