Introduction
The evolutional history of retrograde intrarenal surgery (RIRS) dates
back to the 1970s, but the clinical usage of this technique has gained
increasing popularity in the last 2 decades [1]. The functional
developments of flexible ureteroscopes, lasers and ancillary equipment
have led RIRS to become a significant surgical technique for the
treatment of upper urinary system stones [2]. Due to these
technological advancements, the guidelines for the treatment of urinary
system stone disease have been frequently revised.
Despite these technological advancements, extracorporeal shock wave
lithotripsy (ESWL) still maintains its importance for the treatment of
upper urinary system stones less than 2 cm. in diameter. On the other
hand, recent studies reporting the trends of urolithiasis treatment have
shown a significant increase in the use of ureteroscopy compared to ESWL
[3-5]. RIRS and ESWL are the 2 main treatments for proximal ureter
stones. The European Association of Urology (EAU) guidelines recommend
ureteroscopy as the first-line treatment for proximal ureter stones
>10 mm, and ureteroscopy or ESWL for proximal ureter stones
<10 mm [6]. According to the American Urology Association
and Endourology Society guidelines, ureteroscopy is recommended as the
treatment modality for proximal ureter stones of any size [7,8]. The
efficacy and the safety of RIRS has led this procedure to replace the
role of ESWL in the treatment of proximal ureter stones. On the other
hand, expensive and fragile surgical equipment make this surgery a
costly procedure. For this reason, there are several clinics that
perform ESWL as the first-line treatment of proximal ureter stones and
prefer RIRS as the second-line treatment for patients in which ESWL is
not successful.
ESWL has proven to be a safe and effective method for the treatment of
urinary system stones; however, it may lead to tissue damage, that is
localized around the target zone. Animal studies have documented that
ESWL causes torn vessels with platelet aggregation; vacuolization to
complete necrosis of the epithelium and vascular smooth tissue; and
aggregation of red blood cells and leukocytes in the interstitial space.
The micro-environmental changes lead to tissue oedema and an
inflammatory reaction around the target stone [9]. This reaction may
also occur at the ureter wall around the stone, and may cause the stone
to impact at the ureteric mucosa. The traumatic effect of ESWL on the
ureteral wall and mucosal oedema may be considered a complication of
RIRS that affects the efficiency and safety of this procedure.
We hypothesized that performing ESWL on proximal ureter stones before
RIRS may be a disadvantage for the efficiency and safety of the surgery.
In order to determine the validity of our hypothesis, we evaluated the
effect of pre-RIRS ESWL on the efficiency and safety of RIRS in the
treatment of proximal ureter stones.