The initial clinical application of standard PCNL combined with visual needle nephroscope in the treatment of complex renal calculi

doi:10.21203/rs.3.rs-3149263/v1

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The initial clinical application of standard PCNL combined with visual needle nephroscope in the treatment of complex renal calculi

https://doi.org/10.21203/rs.3.rs-3149263/v1

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Purpose: To present the feasibility, safety and effectiveness of an optimized treatment of complex renal calculi based on visual needle nephroscopy.

Methods: We collected data of 31 patients with complex kidney calculi, who underwent standard PCNL combined with visual needle nephroscope (“needle-perc”, Youcare@, Wuhan, China). The percutaneous nephroscopic working channel was established by visual needle nephroscope, and the primary channel was expanded to 20F to treat most of the main body of the calculi with a 550 μm holmium laser fiber. Visual needle nephroscope was used to locate the renal calyx where the residual calculi were located for precise puncture as a secondary channel, and the residual stones were treated by a 200 μm holmium laser fiber. Clinical data were collected, and intraoperative variables, postoperative complications and outcomes were assessed.

Results: All 31 patients successfully completed the operation without severe complications. The S.T.O.N.E. score of 31 patients before operation was 10.5±0.9 points and above, of which the N score was more than 2 points. The average operation time was (65.5±12.7) minutes, and the average hospital stay was (7.3±2.1) days. After operation, 1 patient developed a fever, which improved after symptomatic treatment by intravenous antibiotics. 2 patients had clinically significant residual fragments, and the stone-free rate of primary operation was 93.5% (29/31).

Conclusions: The optimized operation for the treatment of complex renal calculi based on standard PCNL combined with visual needle nephroscope has good feasibility, safety and effectiveness.

Percutaneous nephrolithotomy

Visual needle nephroscope

Complex renal calculi

Stone free rate

Complication

Urolithiasis is a common disease in urology, and common surgical treatments include percutaneous nephrolithotripsy (PCNL), flexible ureteroscopic lithotripsy (FURSL), extracorporeal shock wave lithotripsy (ESWL), and so on. Treatment of complex stones such as renal staghorn calculi and multiple renal stones is difficult in the clinic, and percutaneous nephrolithotripsy is still the main choice. However, single modality treatment is often not effective, which manifests as a low stone-free rate for the single channel or one-stage surgical lithotripsy, and multi-channels, multiple stages of treatment are often needed, while complications are correspondingly increased[1].

In recent years, the visualization puncture technique has gradually become familiar and applied in percutaneous nephrolithotripsy, which has the advantages of visualization of the puncture process and more precise puncture positioning, and can theoretically reduce the risk of puncture during percutaneous nephrolithotripsy. The visual needle nephroscope, called as “Needle-perc”, which derived on the basis of visualization puncture technique, has also been gradually applied in the treatment of kidney stones as a novel endoscopy [2].

Because of the performance and characteristics of visual needle nephroscope, it is currently mainly used for the treatment of single calyceal stones smaller than 2 cm. However, its lithotripsy efficiency and therapeutic effect for larger complex kidney stones still cannot be the same level as that of conventional percutaneous nephroscopy [3]. We summarize the past years of experience in the treatment of complex kidney stones and try to utilize visual needle nephroscope in combination with traditional percutaneous nephroscopy for the optimization of complex kidney stone treatment options, with the hope of improving the treatment outcomes of complex kidney stone in one-stage surgery, while reducing surgical trauma and the risk of surgery.

2.1. Patients inclusion

We retrospectively evaluated patients with unilateral complex kidney stones who underwent PCNL. This study was approved by the ethics committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. Patients with complex kidney stones were selected, and the inclusion and exclusion criteria were as follows.

Inclusion criteria:

(1) Age between 20 and 70 years;

(2) The patients were diagnosed with unilateral complex kidney stones by ultrasound, plain abdominal radiograph (KUB), and CT scan, which showed clinical features of multiple calyces and multiple stones with a total stone burden of more than 35 mm;

(3) S.T.O.N.E. scores were all 9 and above (where N score was 2 or more, i.e. multiple calyceal involvement or staghorn calculi);

(4) The patients can tolerate percutaneous nephrolithotripsy and completed surgery;

(5) Follow up with postoperative review can be completed.

Exclusion criteria:

(1) Patients with bilateral kidney stones;

(2) Isolated kidney or renal insufficiency (serum creatinine > 177 μmol/L）；

(3) Renal malrotation, horseshoe kidney, or abnormal intrarenal anatomy;

(4) Excessive adiposity, body mass index (BMI) ≥ 35;

(5) Severe scoliosis or left kidney stone with splenomegaly;

(6) Uncorrected coagulation disorder;

(7) Uncorrected severe cardiopulmonary dysfunction;

(8) The untreated stones were complicated by urinary infections.

2.2. Preoperative preparation

All patients were examined with KUB and CT scan of the urinary system before treatment to understand the stone size, location, degree of hydronephrosis, and exclude renal malformations. Urine routine and urine culture were performed, and Stone Co infection was assessed. Biochemical routine examination was performed to evaluate renal function. Complete blood routine, coagulation function, electrocardiogram and other examinations to exclude surgical contraindications. Antibiotics were administered prophylactically 24 hours before surgery.

2.3. Surgical technique

After the success of general anesthesia, the prone position was taken. In combined with the preoperative imaging data, the renal cortex and medulla, upper and lower pole of the kidney, stones, hydronephrotic calyces and perinephric viscera were examined by ultrasound. To establish the percutaneous nephroscopy working channel using a visual needle nephroscope (“Needle-perc”, Youcare^@, Wuhan, China, Figure 1), we tried to select the middle and upper calyces of the postrenal group, and we performed a vertical puncture of the highest point of the dome of the target calyces through 11 intercostal or 12 subcostal under ultrasound real-time guidance. Nephrostomy tract dilatation was completed by peel-away sheath of 20F and the nephroscope was entered into the percutaneous renal channel. The stone was fragmented with the power set at 30-60W (2.0-3.0 J / 15-20 Hz) by a 550 μm holmium laser fiber. After treating most of the main body of the stone by percutaneous nephroscopy, the residue of the calyceal stone was examined by B-ultrasound, and precision puncture was performed by using the “Needle-perc” to locate the calyces where the residual stone was located, as a secondary channel, without dilation of the channel. A 200 μm holmium laser fiber, with the power set at 12-20W (0.8-1.0 J / 15-20 Hz) was used to deal with residual stones, in which larger stone fragments can be removed from the main 20F channel. A 6F ureteral stent tube, main access nephrostomy tube, and balloon urinary catheter were routinely retained after surgery.

2.4. Postoperative review

All patients had the nephrostomy tube removed 3-5 days after surgery and the ureteral stent tube removed 2-3 weeks after surgery. All patients underwent postoperative urinary CT scan and KUB to assess whether there were any residual stones 2-3 days after surgery. Clinically significant residual stones were identified with a diameter of ≥4 mm. The operation time, the proportion of complications, the stone-free rate of one-stage operation were recorded. Complications were classified according to the Clavien grading system. Data were reported as numbers, percentages, and mean ± standard deviation (SD).

All 31 patients successfully completed the operation without severe complications such as hemorrhagic shock, urogenic sepsis and death. The mean age of the patients was 43.1±8.9 years. The mean BMI of the patients was 26.3±2.7. The S.T.O.N.E. score of 31 patients before operation was 9 points and above (the average was 10.5±0.9 points, of which the N score was more than 2 points, that is, multiple renal calyces were involved or staghorn stones). The mean stone size was 4.7±1.1 cm (Table 1).

The average operation time was (65.5±12.7) minutes, and the average hospital stay was (7.3±2.1) days. After operation, 1 patient (3.2%) developed a fever (>38.5℃, Clavien grade II), which improved after symptomatic treatment by intravenous antibiotics. 2 patients had clinically significant residual fragments (≥4 mm), and the stone-free rate of primary operation was 93.5% (29/31) (Table 2).

Complex nephrolithiasis refers to stones > 2.5cm in diameter, staghorn calculi or multiple calculi, and also includes stones in which the affected kidney has associated anatomical and functional abnormalities leading to difficulties in treatment [4]. Okhunov et al. first proposed the application of the S.T.O.N.E. scoring system to estimate postoperative stone-free rate for patients intended to undergo PCNL procedures, and stones scored 9-13 points according to their method of assessment were all high complexity kidney stones [5]. The complexity of the renal stone size and distribution situation focuses on affecting the choice of surgical options [6]. The clinical management of complex kidney stones is more difficult, and percutaneous nephrolithotripsy (PCNL) is currently the preferred option. However, the surgical efficacy of PCNL is greatly affected by the size and distribution of stones, and targeting multiple calyces and multiple stones is less effective than simple kidney stones, especially single-tract PCNL, which has a one-stage procedure with stone-free rates ranging from 40% - 70% [7]. High complexity kidney stone patients with S.T.O.N.E. scores ranging from 9-13 points have a stone-free rate of only about 50% after one-stage PCNL [8]. Multiple calyces, multiple stones presenting as scattered stones or stone branches located in different calyces, and PCNL under a single-tract has difficulty in clearing all stones due to the blind area of the endoscopic field of view, which can further reduce stone clearance if limitations in the length and angle of the calyceal neck are taken into account, or combined conditions such as branched calyces and parallel calyceal stones. Some studies have shown that the stone-free rate of PCNL for complex kidney stones can be improved by using the method of one-stage establishment of multiple tracts [9], and some scholars have proposed that a regimen of multi-stage, fractionated PCNL can be adopted [10], but the former has more surgical complications and greater trauma due to multi-tract factors, while the latter has a heavy economic burden on patients due to multiple procedures and greatly reduced patient compliance.

In recent years, the visualization puncture technique has gradually become familiar and applied in PCNL, which has the advantages of visualization of the puncture process, more precise puncture localization, and can theoretically reduce the risk of puncture during PCNL [11], and the visual needle nephroscope (“Needle-perc”), derived on the basis of visualization puncture technique, has also been gradually applied in the treatment of kidney stones as a novel endoscopic tool. “Needle-perc” has the features of both the puncture needle and the nephroscope [2]. Through the built-in fiberoptic endoscope, the percutaneous renal puncture process can be visualized throughout, while using B-ultrasound-guided, the puncture process can be monitored by a monitor, and if a bleeding tendency is recognized, the puncture can be stopped immediately and further aggravation of bleeding can be avoided [12]. Whereas when the puncture enters the intrarenal collecting system, it can increase the precision of puncture by visually monitoring before dilating the puncture channel, and determine whether the puncture position is ideal, avoids blind dilation [13]. When used as a nephroscope, after visual puncture into the target calyces, through its built-in working channel, 200μm holmium laser can be directly utilized for lithotripsy, which eliminates the need to dilate the puncture channel, thereby greatly reducing surgical trauma and reducing surgical risk [14].

“Needle-perc” is mainly used for the treatment of single calyceal stones smaller than 2 cm. But for larger complex renal stones, its lithotripsy efficiency and therapeutic effect are still inferior to standard PCNL [3]. This study utilizes “Needle-perc” in combination with traditional PCNL to optimize treatment options for complex kidney stones. The visualization needle nephroscope was used to select suitable targets for visualizing percutaneous renal puncture, and was expanded to 18-20F as the main working channel, which was responsible for dealing with most of the stones or stone main bodies, followed by intraoperative ultrasound examination of the residual stone conditions, using the “Needle-perc” to locate the calyces where the residual stone was located for precision puncture as the auxiliary channel, and direct stone fragmentation without expansion of the channel [15]. The results of the present study show that this optimized protocol can improve the outcomes of one-stage PCNL for complex kidney stones while avoiding multichannel expansion and reducing surgical trauma and risks [16]. While dealing with residual stones, due to the presence of the main working channel, it can ensure the effective reflux of perfusion fluid during surgery, thereby the intrarenal pressure can be sufficiently reduced during surgery. This has an important positive effect on reducing the surgical risks caused by abnormally high intrarenal pressure, such as infection, subcapsular hematoma and so on [17].

Intraoperative percutaneous renal puncture approach was performed using B-ultrasound guidance, following the these principles: The point of puncture closest to the skin was chosen in order to achieve a minimum of damage, usually between the posterior axillary line and the scapular line, between the 11th or the 12th subcostal space; The calyces with the highest relative position were selected for puncture, generally with a preference for the middle and upper calyces, in order to achieve maximization of the single channel percutaneous renal field of view [18]; The puncture path, which is an obtuse angle between the direction of the puncture channel and the direction of the calyceal opening, was chosen in an effort to reduce the risk of hemorrhage from calyceal neck laceration; An access needle was chosen for the top of the calyceal dome, and the puncture line was coaxially parallel to the calyceal neck, avoiding direct puncture into the renal pelvis. By these principles, the puncture success rate is significantly improved and complications are reduced [19].

Some researchers have used PCNL in the same period combined with flexible ureteroscopy to treat complex renal stones, which make full use of the advantages and characteristics of both equipment [20]. PCNL combined with flexible ureteroscopy, which also be called endoscopic combined intrarenal surgery (ECIRS), can effectively expand of the field of view for a wider range of intrarenal collecting system, and mutual supplementation of each own field blind area, so as to improve the stone-free rate of one-stage surgery. However, this surgery needs to utilize such a special body position as oblique 45 ° supine, and there is difficulty in body position placement. In addition to the PCNL combined with flexible ureteroscopy has a large loss of endoscopic equipment, and there is a risk of damage to endoscopy intraoperatively. Fortunately, these problems do not exist in surgical methods utilizing standard PCNL combined with “Needle-perc”, whose surgical position can be performed with the standard prone position, and the attrition of endoscopic equipment is also not different from standard percutaneous nephroscopy while effectively improving the effect of surgery [21].

Retrospective nature and the small number of cases are the limitations of the present study, but it will contribute to the literature. Prospective randomized and larger cohorts of comparative studies should be conducted to support our findings, and further follow-up of the treated patients are needed to reach a consensus.

The optimized operation for the treatment of complex renal calculi based on standard PCNL combined with visual needle nephroscope has good feasibility, safety and effectiveness. This optimized operation can give full play to the advantages of visual accurate puncture in the treatment of complex renal calculi, while effectively improving the efficiency of lithotripsy, and significantly reduce the trauma on the patient's body surface. Standard PCNL combined with visual needle nephroscope can reduce the probability of multi-stage or multi-tract surgery, thus reducing the risk of surgery. However, further randomized controlled studies are warranted.

Ethical Approval and Consent to participate

The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. Written informed consent was obtained from individual or guardian participants.

Consent for publication

Not applicable.

Availability of supporting data

All data generated or analysed during this study are included in this published article.

Competing interests

The authors declare that they have no competing interests.

Funding

Project supported by the General Program of the Hubei Health Commission (Grant No. WJ2021M115).

Authors' contributions

Huan Yang was the major surgeon of this subject. Cong Li and Jiaqiao Zhang collected and analyzed the clinical data of this subject. Xiao Yuand Xiaolin Guo guided operative procedures. Engo Ovone Yanne collected and analyzed the clinical data, and was a major contributor in writing the manuscript. All authors read and approved the final manuscript. Lei Cui conducted this investigation. Engo Ovone Yanne and Huan Yang contributed equally to the manuscript.

Acknowledgements

Not applicable.

Tyson MD, 2nd, Humphreys MR: Postoperative complications after percutaneous nephrolithotomy: a contemporary analysis by insurance status in the United States. Journal of endourology 2014, 28(3):291-297.
Xiao B, Ji CY, Su BX, Hu WG, Fu M, Li JX: Needle-perc: a new instrument and its initial clinical application. Chin Med J (Engl) 2020(6):732-734.
Xiao B, Diao X, Jin S, Ji C, Zhang G, Su B, Tang Y, Li J: A Novel Surgical Technique for Treatment of Renal Stones in Preschool-aged Patients: Initial Experience With Needle-perc. Urology 2020, 146:211-215.
Soucy F, Ko R, Duvdevani M, Nott L, Denstedt JD, Razvi H: Percutaneous nephrolithotomy for staghorn calculi: a single center's experience over 15 years. Journal of endourology 2009, 23(10):1669-1673.
Okhunov Z, Friedlander JI, George AK, Duty BD, Moreira DM, Srinivasan AK, Hillelsohn J, Smith AD, Okeke Z: S.T.O.N.E. nephrolithometry: novel surgical classification system for kidney calculi. Urology 2013, 81(6):1154-1159.
Chung BI, Aron M, Hegarty NJ, Desai MM: Ureteroscopic versus percutaneous treatment for medium-size (1-2-cm) renal calculi. Journal of endourology 2008, 22(2):343-346.
Bozkurt OF, Resorlu B, Yildiz Y, Can CE, Unsal A: Retrograde intrarenal surgery versus percutaneous nephrolithotomy in the management of lower-pole renal stones with a diameter of 15 to 20 mm. Journal of endourology 2011, 25(7):1131-1135.
Zhu W, Li J, Yuan J, Liu Y, Wan SP, Liu G, Chen W, Wu W, Luo J, Zhong D et al: A prospective and randomised trial comparing fluoroscopic, total ultrasonographic, and combined guidance for renal access in mini-percutaneous nephrolithotomy. BJU international 2017, 119(4):612-618.
Ghani KR, Andonian S, Bultitude M, Desai M, Giusti G, Okhunov Z, Preminger GM, de la Rosette J: Percutaneous Nephrolithotomy: Update, Trends, and Future Directions. Eur Urol 2016, 70(2):382-396.
Li LY, Gao X, Yang M, Li JF, Zhang HB, Xu WF, Lin Z: Does a smaller tract in percutaneous nephrolithotomy contribute to less invasiveness? A prospective comparative study. Urology 2010, 75(1):56-61.
Kaynar M, Sümer A, Şalvarcı A, Tekinarslan E, Cenker A, Istanbulluoğlu MO: Micropercutaneous nephrolithotomy (microperc) in a two-year-old with the 'all-seeing needle'. Urologia internationalis 2013, 91(2):239-241.
Desai M, Mishra S: 'Microperc' micro percutaneous nephrolithotomy: evidence to practice. Current opinion in urology 2012, 22(2):134-138.
Ganpule AP, Chabra J, Desai MR: "Microperc" micropercutaneous nephrolithotomy: a review of the literature. Urolithiasis 2018, 46(1):107-114.
Ganpule AP, Chhabra JS, Sudharsan SB, Jairath A, Vijaykumar M, Sabnis R, Desai MR: Extending indications of micropercutaneous nephrolithotomy: It is not just about cracking stones. Arab journal of urology 2017, 15(1):17-23.
Tepeler A, Armagan A, Sancaktutar AA, Silay MS, Penbegul N, Akman T, Hatipoglu NK, Ersoz C, Erdem MR, Akcay M: The role of microperc in the treatment of symptomatic lower pole renal calculi. Journal of endourology 2013, 27(1):13-18.
Bader MJ, Gratzke C, Seitz M, Sharma R, Stief CG, Desai M: The "all-seeing needle": initial results of an optical puncture system confirming access in percutaneous nephrolithotomy. Eur Urol 2011, 59(6):1054-1059.
Tepeler A, Akman T, Silay MS, Akcay M, Ersoz C, Kalkan S, Armagan A, Sarica K: Comparison of intrarenal pelvic pressure during micro-percutaneous nephrolithotomy and conventional percutaneous nephrolithotomy. Urolithiasis 2014, 42(3):275-279.
Akbulut F, Ucpinar B, Savun M, Kucuktopcu O, Ozgor F, Simsek A, Gurbuz G: A Major Complication in Micropercutaneous Nephrolithotomy: Upper Calyceal Perforation with Extrarenal Migration of Stone Fragments due to Increased Intrarenal Pelvic Pressure. Case reports in urology 2015, 2015:792780.
Hong Y, Wang H, Xu Q, Chen L, Huang X, Xiong L: Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application. BMC Urol 2022, 22(1):144.
Zeng J, Zhang L, Chen X, He H, Li X: The treatment option for calyceal diverticulum stones: flexible ureteroscopy lithotripsy (FURL) or all-seeing needle-assisted percutaneous nephrolithotomy (PCNL)? Urolithiasis 2022.
Jiang K, Chen H, Yu X, Chen Z, Ye Z, Yuan H: The "all-seeing needle" micro-PCNL versus flexible ureterorenoscopy for lower calyceal stones of ≤2 cm. Urolithiasis 2019, 47(2):201-206.

Table 1 Demographics and stone characteristics of the patients that underwent standard PCNL combined with “Needle-perc”
Parameters	No.(%)	Mean ± SD (range)
Patients	31(100)
Laterality (left/right)	20(64.5)/11(35.5)
Gender (male/female)	18(58.1)/13(41.9)
Age (year)		43.1±8.9(33-60)
BMI (kg/m²)		26.3±2.7(22-32)
Stone size (cm)		4.7±1.1(3-7)
S.T.O.N.E. scores		10.5±0.9(9-12)

Table 2 Perioperative and postoperative data about standard PCNL combined with “Needle-perc”
Parameters	No.(%)	Mean ± SD (range)
Operative time (min)		65.5 ± 12.7(40-100)
Postoperative hospital time (d)		7.3 ± 2.1(5-10)
Stone-free success rate (SFR)	29(93.5%)
Complications (Clavien grade I+II)	1(3.2)
Fever(> 38.5℃)	1(3.2)

No competing interests reported.

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The initial clinical application of standard PCNL combined with visual needle nephroscope in the treatment of complex renal calculi

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