Stone impaction on the ureteral wall is a negative predictive factor that decreases the success of RIRS and increases complication rates in upper ureteral stones. Stone remaining in the ureteral lumen for a long time causes constant irritation in the ureteral wall. As a result of this irritation, inflammation, edema, polyps, and fibrosis occur in the ureteral wall. All these processes and easy mucosal hemorrhage as a result of irritation adversely affect endovision in RIRS. At the same time, large stone volume and poor endovision quality of buried stones may disorient the operator. Sometimes, because the stone cannot be completely broken (partial lithotripsy), the proximal pathway cannot be opened and renal drainage cannot be provided. As auxiliary therapy, percutaneous nephrostomy drainage may be needed. Major complications such as perforation of the ureteral wall and avulsion of the ureter can be seen during RIRS. These problems encountered in patients with normal vertebral curvature may be more advanced in patients with abnormalities in the vertebral curvature such as scoliosis. In the literature, it has been reported that stone-free rates of 75%  and 87.5%  were obtained without major complications in patients with medium-sized kidney stones with spinal deformity with RIRS. We know that percutaneous nephrolithotomy operations with an antegrade approach have been successfully performed in patients with upper ureteral stones [8, 9] with spinal deformity. However, we could not find any study on RIRS in patients with advanced scoliosis with impacted upper ureteral stones.
Treatment of impacted upper ureter stones is very challenging even in patients with normal spinal anatomy [3, 4]. As in patients with normal spinal anatomy, the main treatment choices for patients with impacted upper ureter stones and vertebral deformities are ESWL, RIRS, PCNL, and open/laparoscopic ureterolithotomy [3, 4]. In patients with advanced lumbar scoliosis where the convexity is toward the side with the kidney stone, narrowing the interval between the costal margin and CIAS, it appears difficult to obtain stone-free status due to reasons such as positioning in ESWL, inability to achieve full contact between the ESWL energy head and the patient, and difficulty with spontaneous passing of stone fragments due to immobilization of the patient even if ESWL can be performed. ESWL is reported to have low stone clearance rates (44–73%) in patients with vertebral deformities .
For stones larger than 2 cm, and/or complex partial or staghorn stones, PCNL is known to be the gold-standard treatment . For stones at the upper end of the ureter, PCNL is indicated for patients where methods such as ESWL and RIRS will not be successful. PCNL or M-PCNL is a very effective/successful method to obtain stone-free status, but major peri- and postoperative complications should be remembered. Additionally, in patients with spinal deformity due to advanced scoliosis, risks further increase due to the narrow interval for percutaneous access in standard prone position, increased organ injury risk, and cardiopulmonary and anesthetic risks linked to position. Classic prone, lateral decubitus, and supine PCNL positions may be considered for this surgery according to the degree of deformity of the patient; if possible, fluoroscopic access should be performed accompanied by US . Laparoscopic or open ureterolithotomy surgeries may be chosen if it is understood that other methods will not or cannot be successful for stones at the upper end of the ureter . However, like PCNL, morbidity is higher in laparoscopic and open ureterolithotomy surgeries compared with RIRS and ESWL, and these surgical methods have steep and long learning curves, requiring surgical experience.
Thin flexible endoscopes with 270° flexion capability and laser fiber innovations today allow endoscopic ureterolithotomy surgeries for upper urinary tract stones of nearly all sizes and numbers to be performed by entering the native ureter orifice of the patient to reach the upper ureter and renal collecting system. In fact, even for large stones where PCNL is contraindicated, it may be possible to remove kidney stones with several sessions of RIRS.
Before RIRS, it is not routine to use preoperative DJ stent. It is necessary to use preoperative DJ stent due to ureter stenosis, pyonephrosis, and sepsis. In our patient, on first attendance, the clinical status was severe left renal colic pain, high CRP and WBC values, and fever episodes. For this reason, we identified the patient’s clinical diagnosis as pyonephrosis and urosepsis developing secondary to stone obstruction. Then, we performed emergency renal drainage. Due to tortuosity of the lower ureter, a 0.0038-inch guide wire could not pass proximal of the lower ureter, so the patient was placed in prone position in the same session and a 14F percutaneous nephrostomy catheter was inserted accompanied by US. After the patient’s urine and blood culture/antibiogram tests were cleared of bacterial agents, we performed RIRS.
When working with RIRS in the upper urinary tract, it is recommended that working at low pressure by lowering intrarenal hydrostatic pressure makes it easier to prevent major complications such as sepsis and renal capsular hematoma and ureteral access sheaths (UAS) should be used allowing reentry into the ureter. The risk of UTI and sepsis are reported to increase as the number of stones and dimensions increase in RIRS and the surgical duration lengthens. For this reason, UAS gains more importance to prevent complications in patients with large kidney stones and lengthened surgical duration. however, even in patients with normal vertebral anatomy, UAS may not advance due to reasons such as ureter tortuosity and ureter stenosis. In fact, in our patient, we could not insert UAS due to stenosis or tortuosity of the lower end of the ureter. We think we did not observe peri- and postoperative sepsis and/or renal capsular hematoma and extravasation due to reasons such as the lack of bacterial agent proliferation in urine before surgery, the surgery not lasting longer than 1 hour, and open drainage of the percutaneous nephrostomy catheter during the surgery. In a study of pediatric ureter stone patients with and without spinal deformity, Colangelo et al.  identified serious differences in stone-free rate (SFR) and complication rates for patients with spinal deformity in favor of patients without spinal deformity (success and complications, 61% versus 35.7% and 6.1% versus 40%, respectively). In our case, we did not encounter any complications.
This case report is the first to present RIRS performed for impacted upper ureter stone causing urosepsis in a patient with advanced scoliosis and paraplegia.