Introduction
The European Association Urology (EAU) guidelines recommend
extracorporeal shock wave lithotripsy (SWL) or ureterorenoscopy (URS) as
the first choice of treatment in proximal ureteral stones of less than
10 mm while for those larger than 10 mm, the first option is URS and the
second option is SWL treatment. [1] SWL is the most minimally
invasive and anesthesia-free option in stone treatment. Most patients
can be treated in outpatient settings. Many factors affect the results
of SWL treatment. Proper patient selection increases the success rate,
and stone size is inversely proportional to treatment success. [2]
In addition, it has been stated that the ability of stone targeting
affects the success rate. [3]
In the disease process, if the impacted stones remain in the same
location for a long time, the contact of the stone with the ureteral
mucosa can cause local inflammation and edema [4,5], leading to an
increase in the ureteral wall thickness (UWT). In a previous study, SWL
success was reported to decrease as the UWT increased in patients with
impacted proximal ureter stones. In that study, an impacted stone was
defined as a ureteral stone remaining in the same position (and/or
presence of symptoms) for at least one month, accompanied by the failure
of visualization of the distal segment of the ureter beneath the segment
of the stone on intravenous urography or computed tomography (CT)
urography. [6] However, there is insufficient data in the literature
regarding the definition of impacted ureteral stones. Most definitions
provided are subjective and aim to improve the success of SWL treatment.
When the literature studies are analyzed, a discrepancy is also observed
in relation to the predictive factors affecting success in the SWL
treatment of proximal ureteral stones. [7,8] Therefore, it is still
difficult to choose the appropriate treatment for proximal ureteral
stones.
Innovations in SWL technology have increased the success rate and made
it a favorable choice of treatment. In this study, we aimed to determine
the predictors that might affect the stone-free status. For this
purpose, we investigated the effect of UWT and other variables on the
treatment results in patients who received SWL as the primary treatment
of ureteral stones above the iliac crest
level.