Comparative study of outcome in treating upper ureteral impacted stones using minimally invasive percutaneous nephrolithotomy with aid of patented system or transurethral ureteroscopy

Comparison of the Efficacy of ShuoTong Ureteroscopy and Simple Flexible Ureteroscopy in the Treatment of Unilateral Upper Ureteral Calculi

Background: ShuoTong ureteroscopy (Sotn-ureteroscopy, ST-URS), a new lithotripsy operation method developed on the basis of ureteroscopy, is widely used to treat ureteral stones in China. Its composition includes rigid ureteral access sheath, standard mirror, lithotripsy mirror, and ShuoTong perfusion aspirator (ST-APM). Here, we compared the efficacy and safety of the ST-URS and the flexible ureteroscope (F-URS) holmium laser lithotripsy in the treatment of unilateral upper ureteral calculi. Methods: Retrospective analysis was conducted on the clinical data of 280 patients who met the inclusion 1) urinary tract CT was diagnosed with unilateral single upper ureteral calculi above the L4 lumbar spine; 2) patient age was from 18 to 80 years old; 3) patients were informed and consented to this study; and 4) patients were approved by the hospital ethics committee (proof number: KY-2019-020) and the exclusion criteria for unilateral upper ureteral calculi in the First Affiliated Hospital of Xiamen University from January 2018 to November 2020, and they were divided into the ST-URS group and the flexible ureteroscopy (F-URS) group. Results: The stone-free rate of 1 day after operation of the ST-URS group was significantly higher than the F-URS group (63.71 vs. 34.62%, P < 0.0001). The operative time (38.45 vs. 46.18 min, P = 0.005) and hospitalization cost (27,203 vs. 33,220 Yuan, P < 0.0001) of the ST-URS group were significantly lower than the F-URS group. There were no significant differences in the success rate of ureteral access sheath placement, operative blood loss, stone-free rate of 1 month after operation, postoperative complications, postoperative hospital stay, and postoperative visual analog scale (VAS) pain score between the two groups (P > 0.05). In subgroups of a diameter of calculi ≥ 1.5 cm, calculi CT numerical value ≥ 1,000 Hounsfield unit and the preoperative hydronephrosis range ≥ 3.0 cm, ST-URS shows more advantages in the operative time, stone-free rate of 1 day after the operation, the hospitalization cost, and the incidence of postoperative complications. Conclusion: In unilateral upper ureteral stones treated with a holmium laser, compared with the simple F-URS, the ST-URS has a shorter operative time, lower hospitalization cost, and a higher stone-free rate of 1 day after the operation, suggesting that the ST-URS could be more widely applied in clinics.

Comparison of efficacy and safety of various management options for large upper ureteric stones a systematic review and network meta-analysis

To compare the safety and efficacy of various surgical modalities to manage large (> 1 cm) upper ureter stones. Systematic literature search was conducted to include all randomized studies comparing various treatment options for large (> 1 cm) upper ureteric stones. This review included 13 randomized studies with 1871 patients. Laparoscopic ureterolithotomy (LUL) and percutaneous nephrolithotomy (PNL) were superior to ureteroscopy (URS) and shockwave lithotripsy (SWL) for stone-free rates and need for auxiliary treatments. LUL and PNL were equally effective for stone-free rates and the need for auxiliary treatments. According to SUCRA values for stone-free rates and the need for auxiliary treatments, LUL was the best, followed by PNL. For the duration of surgery, there was no significant difference among all the techniques on network analyses, and SWL was the best according to SUCRA values. Length of hospital stay was significantly shorter for URS than LUL and PNL from network analysis, but there was no significant difference for the rest of the comparisons. Overall complications were similar in all the groups. According to the CINeMa approach, the confidence rating ranged from “very low” to “moderate” for various comparisons. LUL followed by PNL is the most efficacious treatment modality for upper ureteric stones compared to SWL and URS in terms of stone-free rates. However, due to the poor quality of included studies, further high-quality randomized studies are needed.

Study on Clinical Application of Different Ultrasound-Guided Planar Techniques in Minimally Invasive Percutaneous Nephrolithotomy

Objective. The objective is to explore the clinical application value of ultrasound long- and short-axis planar technology in real-time guided puncture in minimally invasive percutaneous nephrology. Methods. The clinical data of 80 patients undergoing real-time ultrasound-guided minimally invasive percutaneous nephrolithotomy from September 2018 to October 2019 were analyzed. The patients were randomly divided into 2 groups with different ultrasound-guided puncture techniques, long-axis in-plane technique and short-axis out-of-plane technique. Results. Minimally invasive percutaneous nephrolithotomies under real-time ultrasound guidance were successfully completed in both groups of patients. The success rate of the first puncture in the short-axis out-of-plane group was significantly higher than that in the long-axis in-plane group, and the differences were statistically significant (P <.05); the total puncture time in the short-axis out-of-plane group was significantly less than the long-axis in-plane group, and the differences were statistical significance (P <.05); there was no significant difference in the single-stage stone removal rate, total percutaneous renal channels, total hospital stay, and rate of complications by the Clavien classification between the 2 groups (P > .05). Conclusion. Ultrasound long-axis and short-axis planar technologies can achieve good clinical application results in real-time guided puncture to establish percutaneous renal channels during minimally invasive percutaneous nephrolithotomy. Compared with the long-axis in-plane technique, the short-axis out-of-plane technique can shorten the puncture time and improve the success rate of the first puncture.

Comparison of antegrade and retrograde ureterolithotripsy for proximal ureteral stones: a systematic review and meta-analysis

Background

Antegrade percutaneous ureterolithotripsy (URSL) could be a treatment option for large and/or impacted proximal ureteral stones, which are difficult to treat. To review the current approach and treatment outcomes and to compare the efficacy of retrograde and antegrade URSL for large proximal ureteral stones, we evaluated the unique perspectives of both surgical modalities.

Methods

This systematic literature review and meta-analysis was performed in July 2020. Articles on human studies and treatment of ureteral stones with URSL were extracted from the PubMed, MEDLINE, Embase, Cochrane Library, Scopus, and the Japan Medical Abstracts Society databases without any language restrictions. The risks of bias for randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were assessed using the Cochrane risk of tool and the Risk of Bias in Non-randomized Studies- of Interventions tool, respectively.

Results

A total of 10 studies, including seven RCTs and three non-RCTs, were selected for the analysis; 433 and 420 cases underwent retrograde and antegrade URSL, respectively. The stone-free rate (SFR) was significantly higher in antegrade URSL than in retrograde URSL (SFR ratio: 1.17, 95% CI: 1.12-1.22; P<0.001), while the hospital stay was significantly longer in antegrade URSL than in retrograde URSL (standardized mean difference: 2.56, 95% CI: 0.67-4.46; P=0.008). There were no significant differences in the operation time and the overall complication rate between the two approaches.

Conclusions

Despite the heterogeneity of data and bias limitations, this latest evidence reflects real practice data, which may be useful for decision making.

Suction Use During Endourological Procedures

PURPOSE OF REVIEW

Equipment used in endourology is constantly evolving due to increasing incidence of urolithiasis. Suctioning has been used mainly in PCNL in conjunction with ultrasonic and ballistic devices for stone removal. Recently technological advances permitted the use of suctioning in more endourological techniques. This review aims to summarize the literature regarding these advancements and analyze the upcoming results.

RECENT FINDINGS

Several centers have conducted experimental and clinical studies on suctioning use during PCNL, mPCNL, and ureteroscopy and concluded that it is an effective and safe adjustment that improves stone-free rates and limits complication rates after these procedures. Suctioning use during common endourological procedures led to improved safety and efficacy among several indications. Due to the observational nature and small sample size of many studies, larger RCTs are needed to make safe conclusions.

Comparison of retrograde ureterorenoscopy (URS) and percutaneous anterograde ureteroscopy for removal of impacted upper ureteral stones >10mm in the elderly population

PURPOSE

We aimed to compare the success and complication rates of the anterograde and retrograde Ureterorenoscopy (URS) for impacted upper ureteral stones in patients > 65 years of age.

MATERIALS AND METHODS

Data of 146 patients >65 years of age and underwent anterograde URS (n=68) in supine position or retrograde URS (n=78) for upper ureteral impacted stones>10 mm between January 2014 and September 2018 were collected prospectively. The groups were compared for success and complication rates, duration of operation, hospital stay, and ancillary procedures.

RESULTS

Anterograde and retrograde URS groups were similar for demographic and stone related characteristics. The success rate of the anterograde URS group was significantly higher than the retrograde URS group (97.1% vs. 78.2%, p=0.0007). The complication rates were similar for the two groups (p=0.86). Clavien grade I and II complications were observed in 3 patients in each group. The mean hemoglobin drop was 0.5 g/dL in the anterograde URS group and blood transfusion was not performed in any of the patients. The mean duration of operation was 41.2±12.5 minutes in the mini-PNL group and 59.6±15.1 minutes in the RIRS group and the difference was statistically significant (p=0.02). The median duration of hospitalization was 1 day for both groups.

CONCLUSIONS

Performing anterograde URS in supine position provided better success rates and similar complication rates compared to retrograde URS. Based on these results anterograde URS shall be considered as one of the primary treatment options for management of impacted upper ureteral stones in the elderly population.

Optimal management of large proximal ureteral stones (>10 mm): A systematic review and meta-analysis of 12 randomized controlled trials

OBJECTIVES

To develop an evidence base to guide clinicians treating adults with large proximal ureteral stones (LPUS) greater than 10 mm.

METHODS

A systematic search of PubMed, EMBASE, and Cochrane Library was conducted to identify randomized controlled trials (RCT) concerning different LPUS management techniques including laparoscopic ureterolithotomy (LU), percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URL) up until March 2020. We followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement when searching and determining inclusion. All included articles were quality assessed and the data analyses were conducted with Review Manager (5.3).

RESULTS

12 RCTs involving 1416 patients met our eligibility criteria and were analyzed. Of these participants, 44.6% (n = 632) underwent URL, 25.5% (n = 361) PCNL, and 29.9% (n = 423) LU. Pooled analysis revealed that URL had a significantly lower stone-free rate (SFR) compared to PCNL and LU (both with p < 0.05). URL had a significantly higher ureteral injury rate compared to LU (Relative risk (RR) = 5.27, 95% confidence interval (CI) 1.52 to 18.22, p = 0.009) and PCNL (RR = 4.11, 95% CI 1.03 to 16.34, p = 0.04). However, no significant differences were found between PCNL and LU in terms of SFR or overall complications, both with p > 0.05. URL initially costs less than PCNL (Weighted mean difference (WMD) -597.35US$, 95% CI -823.10 to -371.60, p < 0.00001), but being less effective creates greater demand for repeat or ancillary treatments compared to LU (RR 15.65, 95% CI 2.11-116.12, p = 0.007) and PCNL (RR 8.86; 95% CI 3.19-24.60; p < 0.00001).

CONCLUSIONS

Both PCNL and LU appear more effective and safer than URL for LPUS; although, LU has higher risk of urine leakage and is more likely incur trauma which requires additional support. However, caution must be taken because this recommendation is based upon a very limited number of clinical studies, and even fewer comparing flexible ureteroscopic technologies. Further prospective real-world studies or RCTs comparing flexible URL, LU and PCNL are required, as well as an in depth analysis of the hidden costs involved in unsuccessful URL treatments.

The Comparison Study of Flexible Ureteroscopic Suctioning Lithotripsy With Intelligent Pressure Control Versus Minimally Invasive Percutaneous Suctioning Nephrolithotomy in Treating Renal Calculi of 2 to 3 cm in Size

Purpose. To compare the efficacy and safety of flexible ureteroscopic suctioning lithotripsy (FURS) using patented designed intelligent irrigation and suctioning intraluminal pressure-control platform and integrated pressure-measuring suctioning ureteral access sheath versus minimally invasive suctioning percutaneous nephrolithotomy (MPCNL) in treating renal calculi at 2 to 3 cm in size. Methods. Ninety-one patients who met the criteria were included in the study. Among these, 46 patients underwent transurethral flexible ureteroscopic lithotripsy and the other 45 patients underwent MPCNL. We retrospectively analyzed the clinical data for the 2 groups and parameters including stone clearance rate, complication rate, average operative time, average postoperative hospitalization duration, and average postoperative hemoglobin level decrease were compared. Results. The hospitalization time for the FURS group was 3.53 ± 1.25 days, which was statistically shorter than that of the MPCNL group, which was 6.54 ± 2.36 days. There was significantly more patients needing pain medication postoperatively in the MPCNL group with statistical difference between the 2 groups ( P = .015). Also, there was more significant hemoglobin level drop in the MPCNL group with statistical difference between the 2 groups. However, there were no statistical differences between the 2 groups on average operative time and stone clearance rate. Conclusion. Both the operative methods are safe and efficacious in treating solitary renal calculus at 2 to 3 cm in size. However, FURS has more advantages including shorter hospital stay, less complication, and less bleeding.

Systematic review and cumulative analysis of the managements for proximal impacted ureteral stones

PURPOSE

To compare the efficacy and safety of different treatment options for the management of proximal impacted ureteral stones (PIUS).

METHODS

A systematic literature search using Pubmed, Medline, Embase and Cochrane Library was conducted to obtain studies concerning different managements for PIUS up to Jan 2018. Summary odds ratios (ORs), standard mean differences (SMDs) or weighted mean differences with their 95% confidence intervals (CIs) were calculated to compare the efficacy and safety of all included treatment methods, registered in PROSPERO under number CRD42018092745.

RESULTS

A total of 15 comparative studies with 1780 patients were included. Meta-analyses of final stone-free rate (SFR) favored percutaneous nephrolithotomy (PCNL) over ureteroscopic lithotripsy (URL) (OR 10.35; 95% CI 5.26-20.35; P < 0.00001), laparoscopic ureterolithotomy over URL (OR 0.11; 95% CI 0.05-0.25; P < 0.00001) and URL over extracorporeal shockwave lithotripsy (OR 0.47; 95% CI 0.28-0.77; P = 0.003). As to complications, PCNL had a significantly higher blood transfusion rate (OR 7.47; 95% CI 1.3-42.85; P = 0.02) and a lower ureteral injury rate (OR 0.15; 95% CI 0.04-0.52; P = 0.003) compared with URL. It also shared a significantly lower stone-retropulsion rate (OR 0.03; 95% CI 0.01-0.15; P < 0.0001) and higher treatment costs (SMD = 2.71; 95% CI 0.71-4.70; P = 0.008) than URL.

CONCLUSIONS

Our meta-analysis suggested that PCNL might be the best option for PIUS owing to its higher successful rate. Complications such as hemorrhage could be decreased by the application on mini-PCNL.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm

INTRODUCTION

The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS).

OBJECTIVE

To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time.

MATERIAL AND METHODS

We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL.

RESULTS

The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate.

CONCLUSIONS

The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

Characteristics and outcomes of ureteroscopic treatment in 2650 patients with impacted ureteral stones

Purpose

To describe stone-free rates and complications of ureteroscopic treatment for impacted compared with non-impacted ureteral stones and evaluate predictive variables for impaction.

Methods

The Clinical Research Office of the Endourological Society prospectively collected 1 consecutive year of data from 114 centers worldwide. Patients eligible for inclusion were patients treated with ureteroscopy for ureteral stones. Patient characteristics, treatment details, and outcomes were compared with regard to stone impaction. Logistic regression analyses were conducted to explore predictive variables for ureteral stone impaction and to analyse the effect of impaction on outcomes.

Results

Of the 8543 treated patients, 2650 (31%) had impacted and 5893 (69%) non-impacted stones. The stone-free rate was 87.1% for impacted stones, which is lower compared with 92.7% for non-impacted stones (p < 0.001). Intra-operative complication rates were higher for impacted stones (7.9 versus 3.0%, p < 0.001). Significantly higher ureteral perforation- and avulsion rates were reported in the impacted stone group compared with the non-impacted stone group. No association between stone impaction and post-operative complications could be shown. Female gender, ASA-score >1, prior stone treatment, positive pre-operative urine culture, and larger stones showed to be predictive variables for stone impaction.

Conclusions

Ureteroscopic treatment for impacted stones is associated with lower stone-free rates and higher intra-operative complication rates compared with treatment for non-impacted stones. The predictive variables for the presence of stone impaction may contribute to the identification of stone impaction during the diagnostic process. Moreover, identification of stone impaction may aid the selection of the optimal treatment modality.

Electronic supplementary material

The online version of this article (doi:10.1007/s00345-017-2028-2) contains supplementary material, which is available to authorized users.

Minimally invasive percutaneous nephrolithotomy improves stone-free rates for impacted proximal ureteral stones: A systematic review and meta-analysis

Background

Urinary stones are common medical disorders and the treatment of impacted proximal ureteral stones (IPUS) is still a challenge for urologists. The aim of this study was to compare the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MI-PCNL) and ureteroscopic lithotripsy (URL) in the treatment of IPUS via a meta-analysis.

Methods

We collected studies using PubMed, Embase, and Cochrane Library from 1978 to November 2016 and analyzed them using Stata 12.0 and RevMan 5.3. Odds ratios (ORs) and standard mean difference (SMD) were calculated for binary and continuous variables respectively, accompanied with 95% confidence intervals (CIs). All study procedures followed the PRISMA guidelines.

Results

Five prospective studies were included in our meta-analysis, with 242 MI-PCNL and 256 URL cases. MI-PCNL was associated with a longer postoperative hospital stay than URL (SMD, 3.14; 95% CI, 1.27 to 5.55). However, no significant difference was observed in operative time (SMD, -0.38; 95% CI, -3.15 to 2.38). In addition, MI-PCNL had higher initial (OR, 11.12; 95% CI, 5.56 to 22.24) and overall stone-free rates (OR, 8.70; 95% CI, 3.23 to 23.45) than URL, along with lower possibilities of surgical conversion (OR, 0.11; 95% CI, 0.03 to 0.49) and postoperative shock wave lithotripsy (OR, 0.06; 95% CI, 0.02 to 0.18). Regarding complications, no significant differences were observed between MI-PCNL and URL (OR, 1.39; 95% CI, 0.93 to 2.10), except for hematuria (OR, 4.80; 95% CI, 1.45 to 15.94).

Conclusions

MI-PCNL is optimal and should be considered as the preferred treatment method for IPUS, as it has better efficacy and a safety profile similar to that of URL. However, further high quality studies with larger sample size are required in future.

A Randomized Study of Minimally Invasive Percutaneous Nephrolithotomy (MPCNL) with the aid of a patented suctioning sheath in the treatment of renal calculus complicated by pyonephrosis by one surgery

Background

Calculus pyonephrosis is difficult to manage. The aim of this study is to explore the value of a patented suctioning sheath assisted minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of calculus pyonephrosis.

Methods

One hundred and eighty two patients with calculus pyonephrosis were randomizely divided into observation group (n = 91) and control group (n = 91). The control group was treated with MPCNL traditionally using peel-away sheath while the observation group was treated with MPCNL using the patented suctioning sheath.

Results

All the patients in the observation group underwent one stage surgical treatment, 14 patients in the control group underwent first-stage surgery with the rest of the group underwent one stage surgery. The complication rate was 12.1% in the observation group, significantly lower than the rate in the control group which was 51.6%; One surgery stone clearance in the observation group was 96.7% while it was 73.6% in the control group; operative time in the observation group was (54.5 ± 14.5) min, compared to (70.2 ± 11.7) min in the control group; the bleeding amount in the observation group was (126.4 ± 47.2) ml, compared to (321.6 ± 82.5) ml in the control group; the hospitalization duration for the observation group was (6.4 ± 2.3) days, compared to (10.6 ± 3.7) days in the control group. Comparison of the above indicators, the observation group was better than the control group with significant difference (p < 0.001 each).

Conclusions

Minimally invasive percutaneous nephrolithotomy with the aid of the patented suctioning sheath in the treatment of calculus pyonephrosis in one surgery is economic, practical, and warrants clinical promotion.

Trial registration

This study was registered with Chinese Clinical Trial Registry on May 18, 2016 (retrospective registration) with a trial registration number of ChiCTR-IOR-16008490.

A Novel Flexible Ureteroscopy with Intelligent Control of Renal Pelvic Pressure: An Initial Experience of 93 Cases

BACKGROUND

Flexible ureteroscopic lithotripsy (URS) is rapidly becoming a first-line therapy for patients with renal and ureteral calculi. Most current medical infusion devices can only monitor infusion flow and pressure, but not renal pelvic pressure (RPP).

PATIENTS AND METHODS

We designed a patented intelligent system to facilitate flexible URS that included an irrigation and suctioning platform and a ureteral access sheath (UAS) with a pressure-sensitive tip, enabling regulation of the infusion flow precisely and control of the vacuum suctioning by computerized real-time recording and monitoring of RPP. A stable RPP was ensured by pressure feedback technology. Ninety-three patients with renal or ureteral calculi participated in the study and received flexible URS. Gravel particles were sucked out automatically during the flexible URS. Patients were evaluated on postoperative days 1 and 30 by X-ray of kidneys, ureters, and bladder to assess stone-free status.

RESULTS

In 81 of the 93 patients, only one surgery was needed to remove the stone. There were nine cases who failed the first surgery due to difficulty in placing the UAS, but flexible URS was performed in these patients after indwelling a Double-J stent to the ureter with the calculus for 2 weeks. Three cases were converted to percutaneous nephrolithotomy due to significant ureteral stenosis. For the 90 patients who underwent flexible URS, the actual RPP was controlled under 20 mmHg with clear operative visualization. The stone-free rates at postoperative days 1 and 30 were 90.0% (81/90) and 95.6% (86/90), respectively. Clavien I complications were noted in 13 cases, while Clavien II complications were noted in two cases. No major complications (Clavien III-V) were noted.

CONCLUSIONS

Our patented system is technically feasible, safe, and efficient for treating upper urinary calculi. The advantages include breaking stones effectively and low complication rates because of its automatic control of RPP.

The New Generation Mini-PCNL System - Monitoring and Controlling of Renal Pelvic Pressure by Suctioning Device for Efficient and Safe PCNL in Managing Renal Staghorn Calculi

INTRODUCTION

In order to better control renal pelvic pressure (RPP), reduce surgical complications and increase operative efficacy of minimally invasive percutaneous nephrolithotomy (MPCNL), we designed an MPCNL with intelligent monitoring and control of RPP and sought to explore its clinical efficacy and characteristics.

SUBJECT AND METHODS

This study included 60 patients with renal staghorn calculi. A 5F ureteral catheter was connected to an invasive blood pressure monitor for monitoring and control of RPP. A 12F renoscope was inserted through a percutaneous tract for lithotripsy using a laser, with the help of an intelligent system to monitor RPP continuously, which includes an irrigation and suctioning platform and an integrated intraluminal pressure sensory PCNL suctioning sheath. Before the lithotripsy, intraluminal pressure control value and perfusion flow were set on the platform.

RESULTS

RPP was maintained at a range of -12 to 2 mm Hg. The mean operative time was 120 min. The mean intraoperative bleeding amount was 100 ml. Fifty-two of the 60 patients the stones were cleared by one surgery.

CONCLUSIONS

In our suctioning MPCNL with the intelligent control of RPP, the intraoperative RPP could be accurately controlled within the preset safety range. The stone clearance rate was high.

Recent advancement or less invasive treatment of percutaneous nephrolithotomy

Since its initial introduction in 1976, percutaneous nephrolithotomy (PCNL) has been widely performed for the management of large renal stones and currently is recommended for staghorn calculi, kidney stones larger than 2 cm, and shock wave lithotripsy-resistant lower pole stones greater than 1 cm. However, except for open and laparoscopic surgery, PCNL is the most invasive of the minimally invasive stone surgery techniques. Over the years, technical and instrumental advances have been made in PCNL to reduce morbidity and improve effectiveness. A thorough review of the recent literature identified five major areas of progress for the advancement of PCNL: patient positioning, method of percutaneous access, development of lithotriptors, miniaturized access tracts, and postoperative nephrostomy tube management. This review provides an overview of recent advancements in PCNL and the outcomes of each area of progress and notes how much we achieve with less invasive PCNL. This information may allow us to consider the future role and future developments of PCNL.

Mini percutaneous nephrolithotomy in the treatment of renal and upper ureteral stones: Lessons learned from a review of the literature

The aim of this review is to present the most recent data regarding the indications of mini percutaneous nephrolithotomy (PCNL), the results and the complications of the method. Medline was searched from 1997 to January 2014, restricted to English language. The Medline search used a strategy including medical subject headings and free-text protocols. PCNL is a well-established treatment option for patients with large and complex renal calculi. In order to decrease morbidity associated with larger instruments like blood loss, postoperative pain and potential renal damage, a modification of the technique of standard PCNL has been developed. This is performed with a miniature endoscope via a small percutaneous tract (11–20 F) and was named as minimally invasive or mini-PCNL. This method was initially described as an alternative percutaneous approach to large renal stones in a pediatric patient population. Furthermore, it has become a treatment option for adults as well, and it is used as a treatment for calculi of various sizes and locations. However, the terminology has not been standardized yet, and the procedure lacks a clear definition. Nevertheless, mini-PCNL can achieve comparable stone-free rates to the conventional method, even for large stones. It is a safe procedure, and no major complications are reported. Although less invasiveness has not been clearly demonstrated so far, mini-PCNL is usually related to less blood loss and shorter hospital stay than the standard method.

Clinical observation of different minimally invasive surgeries for the treatment of impacted upper ureteral calculi

Objective: To compare the clinical effects of three minimally invasive surgeries on the treatment of impacted upper ureteral calculi.

Methods: 135 patients with impacted upper ureteral calculi were selected and randomly divided into three groups (Group A-C) (n=45), which were treated with transurethral ureteroscopic lithotripsy, minimally invasive percutaneous nephrolithotomy, and retroperitoneal laparoscopic ureterolithotomy respectively. Relevant results of the three groups were compared.

Results: The surgery time of Group C was significantly longer than those of Group A and Group B (P < 0.05). The postoperative hospitalization time of Group B was significantly longer than those of Group A and Group C (P < 0.05). 37.78% (17/45) of Group A patients required extracorporeal shock wave lithotripsy, being significantly more than those in Group B (6.67%, 3/45) and Group C (0, 0/45) (P < 0.05). The postoperative calculus clearance rate of Group A (51.11%, 82.22%) was significantly lower than those of Group B (91.11%, 97.78%) and Group C (93.33%, 100%) (P < 0.05). The incidence rates of postoperative complications in Group A-C were 11.11% (5/45), 8.89% (4/45) and 6.67% (3/45) respectively without significant differences (P > 0.05).

Conclusion: The three surgical methods for impacted upper ureteral calculi should be selected according to practical conditions to improve therapeutic effects and to ensure safe surgery.