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

Abstract

BackgroundPercutaneous 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.ObjectivesThe 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.MethodsWe retrospectively analyzed the data of 28 patients. Twenty-four patients had kidney stones measuring > 15 mm (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.ResultsIn group 1, the mean largest and cumulative stone diameters, respectively, were 18.7 ± 5.7 mm and 45.0 ± 12.0 mm. In group 2, the mean volume was 6,288.4 ± 2,733.0 mm3. 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%).ConclusionsMiniJFil® stenting is safe and may be an alternative for the treatment of kidney stones during minimally invasive procedures.

Histological Inflammation in Human Ureter either Healthy or Fitted with Double-Pigtail Stent or a Thin 0.3 F Suture Thread: A Preliminary Study

“…In comparison with the double-pigtail stent, the luminal burden of the ureter only fitted with a pigtail-suture stent was reduced to the threads (i.e., MiniJFil®). The absence of edema around the suture and the luminal freedom may facilitate the elimination of stone fragments [ 6 ].…”

“…The MiniJFil® stent was previously used in another study [ 5 , 6 ]. In the procedure, a polyurethane double-pigtail stent (double-loop ureteral stents, 4.8 F, 26 cm, Coloplast) was sectioned perpendicularly to the main axis, just outside of the renal loop.…”

“…ese surprising properties led us to create the MiniJFil ® , which is reduced to a thread attached to a simple loop of a pigtail stent [5,6].…”

“…In addition, no inflammation was seen on the ureter wall around the suture in endoscopy [ 2 , 5 ]. These surprising properties led us to create the MiniJFil®, which is reduced to a thread attached to a simple loop of a pigtail stent [ 5 , 6 ]. With the suture thread, the entire ureter can be dilated without inflammation, and the luminal vacuity of the ureter is preserved.…”

“…With the suture thread, the entire ureter can be dilated without inflammation, and the luminal vacuity of the ureter is preserved. Thus, the MiniJFil® may facilitate insertion of the ureteral access sheath and accelerate removal of stone fragments, and finally, MiniJFil® may improve outcome [ 6 ].…”