MiniJFil®: A New Safe and Effective Stent for Well-Tolerated Repeated Extracorporeal Shockwave Lithotripsy or Ureteroscopy for Medium-to-Large Kidney Stones?

Background: percutaneous nephrolithotomy (pcnl) is recommended for treating staghorn stones or stones measuring > 20 mm. extracorporeal shockwave lithotripsy (eswl) or flexible ureteroscopy (urs) may be used as a complement. however, pcnl can cause trauma to the kidney parenchyma, and patients may find a noninvasive procedure, such as eswl, to be more attractive. objectives: the aim of this study was to evaluate the clinical efficiency of minijfil® stenting associated with eswl or second-line urs for the treatment of medium-to-large kidney stones. the minijfil® is a stent reduced to a suture of 0.3f attached to a renal pigtail. the entire ureter is occupied only by the suture of the stent. methods: we retrospectively analyzed the data of 28 patients. twenty-four patients had kidney stones measuring > 15mm(group 1) and four patients had staghorn stones (group 2). all of the patients were fitted with minijfil® 2 - 3 weeks before any treatment. eswl was always our first-line therapy. stone-free (sf) status was defined as no evidence of stones. results: in group 1, the mean largest and cumulative stone diameters, respectively, were 18.7±5.7mm^3 and 45.0±12.0mm. in group 2, the mean volume was 6,288.4±2,733.0 mm^3. the overall sf was 96.4% (100% for group 1 and 75% for group 2). the mean number of sessions of eswl and urs, respectively, was 1.4±0.7 and 0.8 ± 0.9 in group 1 and 4.0 ± 2.0 and 1.5± 1.3 in group 2. the mean times to achieve these rates were 3.2±1.7 months and 5.6±2.3 months for groups 1 and 2, respectively. one patient in group 2 was treated with only three sessions of eswl. renal colic was observed in only five patients (17.9%). conclusions: minijfil® stenting is safe and may be an alternative for the treatment of kidney stones during minimally invasive procedures.