Journal of Integrative Nephrology and Andrology

: 2018  |  Volume : 5  |  Issue : 3  |  Page : 100--103

Flexible ureteroscopic lithotripsy is safe and efficient for renal stone <2 cm accompanied with persistent urinary tract infection

Jun Da, Mingxi Xu, Yiwei Wang, Jingshen Zhang, Wenfeng Li, Zhong Wang 
 Department of Urology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China

Correspondence Address:
Zhong Wang
Department of Urology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011


Background and Objective: The aim is to study the efficacy and safety of flexible ureteroscopic lithotripsy (fURSL) for renal stone with persistent urinary tract infection (UTI). Materials and Methods: We retrospectively included 15 cases of patients diagnosed with renal stone together with persistent UTI, who were treated with fURSL from October 2011 to June 2015. A group of 15 patients diagnosed with renal stone, without any sign of persistent UTI, were set as control group. Standard fURSLs were performed by two experienced urologists. Vital signs, routine blood test and kidney, urine, and bladder were observed as well. The double J stent was removed 2–4 weeks after the operation. Results: All operations were done in one-stage. In UTI group, the average operation time was 30 ± 21 min (15–50 min). The stone-free rate (SFR) was 93.3% (14/15). Two cases (13.3%) of fever were observed after the operation, all happened within 6 h postoperatively, with the highest temperature of 39°C. All patients were cured with antibiotics. Conclusions: It is safe to perform fURSL on renal stone patients with persistent UTI under the protection of sensitive antibiotics. The SFR and postoperative complications were acceptable. Low-pressure irrigation and careful postoperative observation are of great importance for these patients.

How to cite this article:
Da J, Xu M, Wang Y, Zhang J, Li W, Wang Z. Flexible ureteroscopic lithotripsy is safe and efficient for renal stone <2 cm accompanied with persistent urinary tract infection.J Integr Nephrol Androl 2018;5:100-103

How to cite this URL:
Da J, Xu M, Wang Y, Zhang J, Li W, Wang Z. Flexible ureteroscopic lithotripsy is safe and efficient for renal stone <2 cm accompanied with persistent urinary tract infection. J Integr Nephrol Androl [serial online] 2018 [cited 2019 Oct 17 ];5:100-103
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Full Text


Renal stones <2 cm are mostly treated by extracorporeal shock wave lithotripsy and/or ureteroscopic lithotripsy (URSL), either semi-rigid or flexible.[1] The previous study showed that pyuria and infectious stones were highly related to infectious complications after URSL.[2] The existence of uncontrolled urinary tract infection (UTI) is considered as one of the contra-indications of URSL, due to its risk of causing urosepsis.[3]

As required by almost all urolithiasis guidelines, endoscopic intrarenal surgery should be performed in a relatively noninfection environment, ideally. However, the reality is that sometimes renal stones and UTI is a pair of mutualism. Both factors reinforce each other, which makes URSL a risky choice.

In our department, we had some renal stone patients come with pyuria and/or bacteriuria that could not be well controlled, even sensitive antibiotics were applied for more than 2 weeks according to their results of mid-stream urine culture. We defined the conditions of these patients as persistent UTI. Persistent UTI made it risky to perform URSL, while the renal stone continuously causing consequences, such as nephrohydrosis and lumbar pain. In this study, we treated renal stone patients with persistent UTI using flexible URSL (fURSL) and found the results were acceptable in experienced hands.

 Materials and Methods

General information

We retrospectively reviewed 30 cases of renal stone patients treated in our hospital from October 2011, to June 2015. Among them, 15 cases with evidences of UTI, such as pyuria and/or bacteriuria, were set as UTI group. Another 15 cases without any signs of UTI were set as control group. All patients were treated by fURSL. All patients in UTI group complained about frequency, urgency, dysuria, and/or fever. These patients were treated by sensitive antibiotics according to mid-stream urine culture results for at least 2 weeks. However, the following urine test still showed white blood cell (WBC) >100/μL (normal range <20/μL). We defined these conditions as persistent UTI.

General information, such as age and gender was collected accordingly. During hospitalization, data were collected, such as urine test, mid-stream urine culture, noncontrast computed tomography (CT), size of renal stone, operation time, length of hospital stays, and blood test after operation. Three months after the operation, results of the urine test and ultrasound scan/CT were collected.

Treatment strategy

For the control group, fURSL was performed routinely. For UTI group, sensitive antibiotics were given according to urine culture results for at least 2 weeks. All operations in UTI group were performed after normal body temperature obtained for at least 3 days, routine urine test still showed WBC count higher than the normal range but <250/μL.

FURSL was performed in one stage under general anesthesia. Patients were in the bladder lithotomy position. A 7.5/9 French Wolf semi-rigid ureteroscope was inserted under the guidance of a guide wire. After dilation by the semi-rigid ureteroscope and observation to exclude ureteral stricture, a Cook 12/14 French access sheath was inserted along the guide wire. Then a Storz Flex-X[2] 7.5 French flexible ureteroscope (working channel 3.6 French) was inserted through the access sheath. When stone was found, a 220 μm laser fiber was used for stone fragmentation. The laser power was set to 0.8–1.0J at the frequency of 5–10 Hz. After stone fragmentation, a 1.7 French Cook NGage® nitinol stone extractor was used to remove fragments larger than 2 mm, and pus mosses in UTI group. Finally, a 6 French double J stent was implanted. A kidney, urine, and bladder was taken before discharge. In UTI group, sensitive antibiotics were continuously used for another 3–5 days orally or intravenously.

Postoperational evaluation and follow-up

Urine tests and ultrasound scans/non A contrast CT scans were performed 2 weeks after the operation to evaluate stone clearance rate and UTI status. No stone residual or residual <4 mm in CT scan was considered as a successful operation result. Urinary WBC count <20/μL was considered as a successful anti-infection treatment. Then, the double J stent was removed under local anesthesia using ureteroscope.

Three months later, all patients were followed up for frequency, urgency, dysuria and fever. A urine test and noncontrast CT scan were performed again to evaluate patient's status.

Statistical analysis

All data were analyzed using SPSS version 15.0 (SPSS Inc., Chicago, IL, USA) 11, P < 0.05 was defined as statistically significant.


General information

In the control group, there were five cases of male and 10 cases of female with the average age of 41.93 ± 6.8 years (32–63 years). CT scan before operation showed all cases were unilateral urolithiasis, 8 cases of the left side and 7 cases of the right side, with the average size of 12.5 ± 3.6 mm (9–17 mm) [Table 1]. There were no evidences of hydronephrosis in these cases. The average urine WBCs count was 33.87 ± 11.03/μL (10–50/μL). All urine culture came back with negative results.{Table 1}

In the UTI group, there were 5 cases of male and 10 cases of female with the average age of 44.93 ± 13.07 years (34–64 years). CT scan before operation showed all cases were unilateral urolithiasis, 9 cases of the left side and 6 cases of the right side, with the average size of 15.2 ± 4.0 mm (11–20 mm) [Table 1]. There were 12 cases of mid-calyx stones, three cases of lower-calyx stones. There were no evidences of hydronephrosis in these cases. The average urine WBCs count was 33.87 ± 11.03/μL(10–50/μL). Before antibiotics treatment, the urine culture showed 10 cases of Escherichia coli infections and 5 cases of Proteus infections. All patients' body temperature ranged from 37.5°C to 39.6°C. Antibiotics were administrated for about 2 weeks according to the urine culture results. Before the operations, all urine culture came back with negative results. Moreover, the patients were in normal body temperature. However, urine test still showed WBC 107.67 ± 27.05/μL (80–160/μL).

Operation information

All operations were done in one stage. The average operation time was 33.33 ± 10.97 min (20~50 min) in the control group, and 36.00 ± 9.10 min (20~50 min) in the infection group (P > 0.05). In infection group, urinary cloudiness was found in renal pelvis, together with some floating floccules. Two cases of stones were found to be covered with pus substances. There were two cases of increased body temperature recorded in UTI group 6 h after the operations. The patients' body temperatures ranged from 38.5°C to 39°C, and dropped to normal range after appropriate treatment. No chills, variation of heart rate or blood pressure were recorded. Day one postoperatively, routine blood test showed mean WBC count of 7.27 ± 1.49 × 109/L (5 × 109/L-10 × 109/L) in control group, and 12.07 ± 2.31 × 109/L (9 × 109/L-15 × 109/L) in UTI group (P < 0.05). The average hospitalization was 2.93 ± 0.26 days (2–3 days) in the control group, and 5.00 ± 1.00 days (3–7 days) in UTI group (P < 0.05) [Table 2].{Table 2}


Stone-free rate (SFR) was 100% (15/15) in control group and 93.3% (14/15) in UTI group 2 weeks after the operation, respectively. Routine urine test showed WBC count of 10.33 ± 7.19/μL (0–20/μL) in control group and 20.33 ± 13.29/μL (0–40/μL) in UTI group (P > 0.05) [Table 3]. In all cases, double J stents were removed 2 weeks after operation. No recurrences of UTI or stones were recorded.{Table 3}


Urosepsis is one of the most severe complications of endoscopic treatment of urolithiasis, which could be life-threatening situations to patients. Studies showed that intra-renal endoscopic surgery of urolithiasis with uncontrolled UTI could lead to urosepsis and other severe complications.[4],[5],[6] As endoscopic lithotripsy and lithotomy are applied more and more commonly in clinical practice, the incidence rate of urolithiasis has been reported to increase significantly.[7],[8] Hence, guidelines suggested that ideally all URSLs should be performed under well-controlled UTI. During clinical practice in our department, uncontrolled UTI did lead to life-threatening situations when we started to use ureteroscopic surgery as the treatment of upper urinary tract stones. But now whatever the treatment is going to be, its of our priority to evaluating UTI status for all urolithiasis patients.

As operation time is reported to be highly related to the incident rate of complications after ureteroscopic surgery.[9],[10] We take shortening operation time of great importance while dealing with urolithiasis patients with persistent UTI. In our experience, the cooperation of two experienced urologists performing URSL and lithotomy could make the operation highly efficient and safe, and lower the risk of urosepsis after the operation. Hand irrigation inexperienced hand could guarantee clear vision while keeping irrigation flow at the possible lowest rate.[11],[12] This trick would keep intrarenal pressure as low as possible during the operation and keep high pressure caused intrarenal retrograde infection to the lowest level. Moreover, the fluent cooperation between two experienced urologists could save communication time while irrigating and extracting. Thus shorten the operation time significantly, compared to one experienced urologist only.

Careful postoperation monitor is also very important for urolithiasis patients with persistent UTI. Studies have shown that 2 h after the operation is the most critical time window for uroseptic shock treatment.[13],[14],[15] Early diagnosis and treatment of septic shock could make great differences. In our experience, vital signs monitoring and routine blood test are the easiest and solid proofs for early detection of urosepsis. Treatment based on these proofs is always accurate. Laboratory tests results later could improve the treatment and guarantee the safety of urolithiasis patient with persistent UTI.


FURSL is safe and efficient for the treatment of renal stone <2 cm with persistent UTI. The SFR is high, and complication rate is low and controllable. While two experienced hands are preferred for a single operation. Moreover, postoperation monitor is of great importance for a satisfying outcome.

Financial support and sponsorship

This work is supported by Shanghai Clinical Special Project on Integrated Chinese and Western Medicine, No. ZHYY-ZXYJHZX-1-03.

Conflicts of interest

There are no conflicts of interest.


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