The choice of management for impacted proximal ureteral calculi has been controversial for a long time, but the ultimate goal is for patients to be completely stone-free and to avoid complications. Some clinical factors may play important role, in addition to experience of the surgeon and the choice of treatment [15–16].
Retrograde intrarenal surgery mainly includes semi-rigid ureteroscopy and flexible ureteroscopy. RIRS is generally safe and provides rapid postoperative recovery, but RIRS also has significant disadvantages. Poor irrigation control leads to stone fragments being flushed backward into the renal collection system.
Urinary tract infections and ureteral strictures are serious complications of RIRS, and severe cases can lead to urosepsis and even septic shock . The main mechanism of infection is high intraoperative irrigation pressure, resulting in the reflux of bacterial endotoxins into the circulation system [17, 18].Study has showed that the use of ureteral access sheaths (UAS) can significantly decrease intro-renal pressure during RIRS . Holmium laser lithotrispy increases the risk of ureteral stricture . Famet al. reported that the incidence of ureteral stricture after operation is 3–24% . Ureteral stricture can be caused by thermal damage during holmium laser lithotripsy. Thermal effect can damage epithelial structure and blood supply of the ureter wall . However, no patients with ureteral stricture after RIRS were identified in the present study.
The advantage of PCNL lies in its high SFR; Gdoret al. found that the success rate of ureteroscopy in the treatment of impacted ureter stones is only 56% .
PCNL has advantages in both the initial and overall stone clearance efficiency when compared to RIRS.
Study has shown that the adjuvant surgery rate of RIRS is also much higher than that of PCNL [17
]. PCNL also has many serious complications such as damage to the adjacent organs, hemorrhage and severe postoperative infections [23
There are many treatment methods for impacted proximal ureteral calculi. In order to achieve better surgical outcomes, preoperative risk factors associated with calculi can be screened for and scored into different groupings. Kokovet al. studied the size of stones as the only independent predictor of stone-free status after percutaneous nephroscopy. A prospective study by Gucuket al. indicated that stone density is a parameter that significantly impacts SFR . Yuruket al. found that previous ESWL could affect PCNL efficacy and make the operation more difficult . Kadihasanoglu et al. showed that hydronephrosis is the main factor affecting SFR after PCNL .Haas found that delayed decompression in patients with obstructive calculi complicated with urinary tract infection was associated with an increased risk of death. . Based on the findings from the previous studies, five preoperative stone-related high-risk factors (stone diameter, stone hardness, history of previous lithotripsy, and degree of hydronephrosis, infection) were selected for evaluation and analysis in the present study.
After scoring and grouping preoperative high-risk factors of the stones, the patients were classified as uncomplicated cases (score < 3 points) group and complicated cases (score ≥ 3 points) group, perioperative data were compared between and within groups in both PCNL and RIRS cases. In the complicated cases, the operation time, length of hospital stay, and complication rate of RIRS significantly increased, whereas SFR gradually decreased. These findings indicate that the efficacy of RIRS on complicated cases is low. The advantage of the short duration of the hospital stay in the uncomplicated RIRS cases no longer existed, and surgical efficacy was significantly decreased.
The present study has some limitations. First, the study was a retrospective analysis that was conducted among patients enrolled at a single center. Second, the number of patients included was relatively small. A prospective, multi-center, randomized controlled trial will be expected in the future to validate the scoring system.
In conclusion, for impacted proximal ureter stone, PCNL had a better SFR and higher surgical efficacy, whereas RIRS had higher surgical safety parameters, a shorter perioperative period, but a lower initial SFR. Both methods are effective in treating uncomplicated impacted proximal ureter stone; but PCNL is often more advantageous for complicated cases (score ≥ 3 points). Thus, when choosing a better treatment method for complicated impacted proximal ureteral calculi, we believe that PCNL is the preferred choice over RIRS.