Long-term functional outcome of percutaneous nephrolithotomy in solitary kidney

2022 Recommendations of the AFU Lithiasis Committee: Specific cases - chronic kidney disease, bilateral stones, and solitary kidney

Chronic kidney disease, diabetes and hypertension are risk factors of kidney function impairment. The relative risk of kidney failure is 1.52 in patients with urinary stone disease. The various techniques used to remove upper urinary tract stones generally do not alter kidney function in patients with normal kidney function and may sometimes improve kidney function or slow its deterioration in patients with kidney disease. Compared to the asynchronous treatment of bilateral renal and ureteral stones, concomitant treatment is associated with higher risk of anuria and the need of additional interventions, in the absence of postoperative stenting. For the treatment of solitary kidney stones, the absence of postoperative stenting increases the risk of postoperative anuria. Moreover, the multiplication of percutaneous nephrolithotomy access tracts increases the risk of bleeding and that of kidney function impairment. METHODOLOGY: These recommendations were developed according to two methods: the Clinical Practice Recommendations (CPR) method and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU Guidelines on urolithiasis. 2022] and their adaptability to the French context.

Comparison of the effect of miniaturized and standard percutaneous nephrolithotomy on renal function assessed with DMSA scintigraphy

INTRODUCTION AND OBJECTIVES

We aimed to present a clinical study that compares standard and miniaturized percutaneous nephrolithotomy (PNL) effects on kidney function with scintigraphic imaging in primary kidney stone patients.

MATERIALS AND METHODS

One hundred four patients were included in this prospective study between May 2014 and February 2017. Eligible patients were divided into two groups miniaturized PNL (mPNL) and standard PNL (sPNL) with matched-pair analysis (1:1 scenario). Technetium-99m Dimercaptosuccinic Acid cortical scintigraphy imaging was performed before and after the operation.

RESULTS

There were no differences between the two groups in terms of success rate (mPNL (63.5%) vs. sPNL (71.2%), p=0.403), serum creatinine, glomerular filtration rate, split renal functions pre- and postoperatively (p≥0.05). There was no relationship between the type of operation and new scar formation (p=0.780). The rates of serious complication (grades 3 and 4 according to modified Clavien-Dindo Classification) were higher in sPNL (p=0.034). Stone burden, duration of operation, hemoglobin drop, multiple access, blood transfusion, and angioembolization were higher in patients with scarred kidneys (p<0.001, p=0.008, p=0.004, p<0.001, p=0.003, p=0.001, respectively). In multivariate analysis, only multiple access was found statistically significant for predicting new scar formation (p<0.001, OR: 24.28).

CONCLUSIONS

Miniaturized and standard PNL are reliable and successful operations for treating large kidney stones. No significant difference was found between the operation types regarding a decrease in renal function.

Outcomes of ultrasound-guided percutaneous nephrolithotomy for the treatment of large stones within non-functioning atrophic kidneys

OBJECTIVES

To evaluate outcomes in patients who underwent total ultrasound-guided percutaneous nephrolithotomy for the management of large stones (>2 cm) within non-functioning atrophic kidneys, and to identify risk factors associated with postoperative persistence of urinary tract infection symptoms in such patients.

METHODS

Between December 2014 and May 2019, 56 patients with large stones within non-functioning atrophic kidneys were treated at Beijing Tsinghua Changgung Hospital, Beijing, China, with total ultrasound-guided percutaneous nephrolithotomy. Factors including age, sex, previous medical history, stone burden, stone composition, stone-free rate, complication rate and postoperative urinary tract infection symptoms were retrospectively evaluated. Uni- and multivariate analyses were carried out to identify risk factors that predict persistence of urinary tract infection symptoms after percutaneous nephrolithotomy in such patients.

RESULTS

The final stone-free rate after auxiliary treatments was 87.5%. The overall complication rate was 17.9%. After a median follow-up period of 12 months (range 6-40 months), three patients (5.4%) ultimately underwent nephrectomy. A total of 44 patients (78.6%) had no symptoms of urinary tract infection during follow up, whereas 63.6% of patients with diabetes continued to show persistent urinary tract infection symptoms at the latest follow up. Five patients (8.9%) showed improved total renal function, while most patients (83.9%) showed a stable estimated glomerular filtration rate. Diabetes was the only factor showing statistical significance in both univariate and multivariate analyses that predicted persistence of urinary tract infection symptoms after treatment with percutaneous nephrolithotomy.

CONCLUSIONS

Ultrasound-guided percutaneous nephrolithotomy is a safe and feasible procedure that can be carried out in patients with large stones within non-functioning atrophic kidneys. However, for such patients with diabetes, percutaneous nephrolithotomy is not recommended.

Single- versus Multiple-Tract Percutaneous Nephrolithotomy in the Surgical Management of Staghorn Stones or Complex Caliceal Calculi: A Systematic Review and Meta-analysis

Objective

To assess current evidence on the effectiveness and safety of single- versus multiple-tract percutaneous nephrolithotomy in the surgical management of complex caliceal calculi or staghorn stones through a comprehensive literature review.

Methods

A comprehensive literature review of articles investigating the clinical efficacy and safety of single- versus multiple-tract percutaneous nephrolithotomy was performed. Relevant literature was obtained by systematically searching PubMed, EMBASE, and the Cochrane Library through May 2020. We followed the search strategy based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The primary outcomes, including the stone-free rate (SFR), and secondary outcomes (peri- and postoperative complications and operative data) were evaluated using RevMan 5.3 statistical software.

Results

Ten studies involving 1844 patients with complex caliceal calculi or staghorn stones met the inclusion criteria. Single-tract percutaneous nephrolithotomy (STPCNL) had noninferior clinical efficacy with respect to the immediate SFR (odds ratio (OR) = 0.80, 95% confidence interval (CI) (0.46 to 1.38), p = 0.42) and 3-month SFR (OR = 1.22, 95% CI (0.38 to 3.92), p = 0.74) compared with multiple-tract percutaneous nephrolithotomy (MTPCNL). In addition, pooled analyses showed that STPCNL resulted in significantly lower hemoglobin decreases (MD = −0.46, 95% CI (-0.68 to -0.25), p < 0.0001), fewer blood transfusions (OR = 0.48, 95% CI (0.34 to 0.67), p < 0.0001), and fewer pulmonary complications (OR = 0.28, 95% CI (0.09 to 0.83), p = 0.02) than MTPCNL. However, the overall evidence was insufficient to suggest a statistically significant difference for other adverse events.

Conclusion

This meta-analysis indicated that STPCNL is an effective method for treating complex caliceal calculi or staghorn stones. Compared with MTPCNL, STPCNL not only yields similarly high SFRs but also is associated with many advantages, less blood loss, fewer blood transfusions, and fewer pulmonary complications without an increase in other complications. However, the findings of this study should be further confirmed by well-designed prospective randomized controlled trials (RCTs) with a larger patient series.

Are endourological procedures for nephrolithiasis treatment associated with renal injury? A review of potential mechanisms and novel diagnostic indexes

Nephrolithiasis is one of the most common urological conditions with a huge socio-economic impact. About 50% of recurrent stone-formers have just one lifetime recurrence and >10% of patients present with a high recurrent disease requiring subsequent and sometimes multiple surgical interventions. The advent of new technology has made endourological procedures the pinnacle of stone treatment, including procedures like percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery and miniaturized PCNL procedures. Researchers have primarily focused on comparisons with respect to stone-free rates, procedure parameters and post-operative complications. However, the effect of these three procedures on renal function or indexes of renal injury has not been sufficiently examined. This was only reported in a few studies as a secondary objective with the use of common and not the appropriate and detailed renal parameters. This review presents current literature regarding the use of novel and highly predictive biomarkers for diagnosing acute kidney injury, discusses potential mechanisms through which endourological procedures for renal stone treatment may affect renal function and proposes areas with open questions where future research efforts in the field should focus.

Role of Endourological Procedures (PCNL and URS) on Renal Function: a Systematic Review

PURPOSE OF REVIEW

To present the latest evidence related to the impact of ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) on the renal function.

RECENT FINDINGS

Our review suggests that the overall renal function is not detrimentally affected by endourological interventions (URS, PCNL). This is however influenced by the preoperative renal function, presence of comorbidities such as diabetes and hypertension. For PCNL procedures, tract multiplicity, preoperative UTI, and postoperative bleeding also contribute to a decline in renal function. This review suggests that endourological interventions do not adversely affect renal function and tend to improve it in patients who do not have a poor renal function prior to the procedure. Several factors including poor preoperative renal function, diabetes, hypertension, and multiple percutaneous tracts appear to predispose patients to declining renal function after procedure, and these patients should be counseled for and followed up appropriately.

Endourologic Management (PCNL, URS, SWL) of Stones in Solitary Kidney: A Systematic Review from European Association of Urologists Young Academic Urologists and Uro-Technology Groups

Introduction: Urolithiasis in solitary kidney (SK) presents significant management dilemma as any insult to the kidney or its drainage can lead to significant morbidity. The treatment options include shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and ureteroscopy (URS). Our aim was to conduct a systematic review of literature on all available endourologic techniques reporting on the management of stones in an SK. Materials and Methods: We conducted a systematic review according to the Cochrane and PRISMA checklist for all English-language articles from inception to December 2018. All studies with a minimum of 10 patients that reported on endourologic management (SWL, PCNL, or URS) were included. Data were extracted for patient and stone demographics, outcomes including stone-free rate (SFR), adverse events, and renal function. Results: After an initial search of 553 articles, 27 were included for the final review (10 PCNL, 1 mini-PCNL, 9 URS, 1 SWL, and 6 comparative studies). The choice of treatment seemed to be based on stone size, with PCNL, URS, and SWL offered for mean stone sizes between 25-50, 10-28, and 12-15 mm, respectively. PCNL, URS, and SWL were reported in 1445, 792, and 186 patients, respectively, with a final SFR of 67%-97.7%, 43%-100%, and 73%-80% and a complication rate of 26.4%, 15%, and 16.7% across the three groups. The renal function deterioration was reported in 4/16 PCNL studies and in 1/15 URS studies, while it remained unaffected in the SWL study. Conclusions: Our review shows a rise of endourologic techniques in the management of stones in SK. Although PCNL was used for larger stones, it had a higher risk of major complications, including blood transfusion. While a good SFR was obtained for patients irrespective of the treatment modality, the selected intervention needs to be balanced with its safety profile and the need for ancillary procedures.

Acute kidney injury after percutaneous nephrolithotomy for stones in solitary kidneys

OBJECTIVES

The aim of this study was to report the incidence, severity, outcome and risk factors of acute kidney injury (AKI) following percutaneous nephrolithotomy (PNL) in solitary kidneys.

METHODS

The study included consecutive adult patients who underwent PNL for treatment of calculi in a solitary kidney between May 2012 and July 2015. Patients with congenital renal anomalies or with stages 4 and 5 chronic kidney disease (CKD) were excluded. Serum creatinine levels were measured the day before PNL, daily after PNL for 2-5 days and after 3 months. AKI was depicted according to changes in early postoperative serum creatinine levels and its severity was determined based on the Acute Kidney Injury Network (AKIN) classification. The outcome of AKI was evaluated after 3 months by changes in the stage of CKD. Univariate and multivariate statistical analyses were conducted to determine risk factors for developing AKI.

RESULTS

The study included 100 patients (62 males) with a mean ± SD age of 50 ± 11.7 years. Complications were reported for 27 patients. AKI developed in 25 patients; at the 3 month follow-up, 23 of them (92%) had completely recovered from AKI and two (8%) had developed stage 4 CKD. Independent risk factors for developing AKI were multiple PNL tracts and postoperative ureteric obstruction (relative risks were 14 and 22, respectively).

CONCLUSIONS

The incidence of AKI was 25% after PNL for a solitary kidney. The likelihood of renal function recovery was 92%. Multiple PNL tracts and postoperative ureteric obstruction were risk factors for developing AKI.

The Risk of Chronic Kidney Disease Associated with Urolithiasis and its Urological Treatments: A Review

PURPOSE

Urolithiasis can impair kidney function. This literature review focuses on the risk of kidney impairment in stone formers, the specific conditions associated with this risk and the impact of urological surgery.

MATERIALS AND METHODS

The PubMed® and Embase® databases were searched for publications on urolithiasis, its treatment, and the risk of chronic kidney disease, end stage renal disease and nephrectomy in stone formers.

RESULTS

In general, renal stone formers have twice the risk of chronic kidney disease or end stage renal disease, and for female and overweight stone formers the risk is even higher. Patients with frequent urinary tract infections, struvite stones, urinary malformations and diversions, malabsorptive bowel conditions and some monogenic disorders are at high risk for chronic kidney disease/end stage renal disease. Shock wave lithotripsy or minimally invasive urological interventions for stones do not adversely affect renal function. Declines in renal function generally occur in patients with preexisting chronic kidney disease or a large stone burden requiring repeated and/or complex surgery.

CONCLUSIONS

Although the effect size is modest, urolithiasis may cause chronic kidney disease and, thus, it is mandatory to assess patients with renal stones for the risk of chronic kidney disease/end stage renal disease. We suggest that all guidelines dealing with renal stone disease should include assessment of this risk.

Comparison of Effect of Minimally Invasive Percutaneous Nephrolithotomy on Split Renal Function: Single Tract vs Multiple Tracts

OBJECTIVES

To observe serum creatinine (SCr) and treated side glomerular filtration rate (TGFR) variations in patients with upper urinary tract calculi after minimally invasive percutaneous nephrolithotomy (MPCNL).

PATIENTS AND METHODS

A total of 178 patients underwent MPCNL in our institute and they were retrospectively evaluated between May 2014 and February 2016. SCr and TGFR variations were observed with renal scintigraphy using 99mTc-diethylene triamine pentaacetic acid (^99mTc-DTPA) preoperatively and after at least 6 months of follow-up (FU). The patients were categorized into two groups according to the number of percutaneous access tracts: group I (single tract, n = 122) and group II (multiple tracts, n = 56).

RESULTS

At a mean FU of 7.6 months, SCr dropped from 192.9 ± 151.9/L to 167.6 ± 113.9 μM (13.15% decrease, p = 0.008) and TGFR increased from 29.8 ± 21.2 mL/minute preoperatively to 32.7 ± 22.5 mL/minute postoperatively (9.79% increase, p = 0.022) in group I. Similarly, SCr dropped from 238.5 ± 130.1 to 215.8 ± 128.1μ (9.50% decrease, p = 0.013) and TGFR increased from 29.6 ± 21.4 mL/minute preoperatively to 32.9 ± 25.1 mL/minute postoperatively (11.17% increase, p = 0.014) in group II. No statistically significant difference between two groups according to SCr or TGFR variation was observed (p > 0.05).

CONCLUSIONS

Stone clearance resulted in improvement of split kidney function after single tract or multiple tract MPCNL. Single tract or multiple tract MPCNL did not show statistically significant difference in split renal function postoperative recovery.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of kidney stones up to 2 cm in patients with solitary kidney: a single centre experience

BACKGROUND

To compare the treatment outcomes between percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for the management of stones larger than 2 cm in patients with solitary kidney.

METHODS

One hundred sixteen patients with a solitary kidney who underwent RIRS (n = 56) or PCNL (n = 60) for large renal stones (>2 cm) between Jan 2010 and Nov 2015 have been considered. The patients' characteristics, stone characteristics, operative time, incidence of complications, hospital stay, and stone-free rates (SFR) have been evaluated.

RESULTS

SFRs after one session were 19.6% and 35.7% for RIRS and PCNL respectively (p = 0.047), but the SFR at 3 months follow-up comparable in both groups (82.1% vs. 88.3%, p = 0.346). The calculated mean operative time for RIRS was longer (p < 0.001), but the mean postoperatively hospital stay was statistically significantly shorter (p < 0.001) and average drop in hemoglobin level was less (p = 0.040). PCNL showed a higher complication rate, although this difference was not statistically significant.

CONCLUSIONS

Satisfactory stone clearance can be achieved with multi-session RIRS in the treatment of renal stones larger than 2 cm in patients with solitary kidney. RIRS can be considered as an alternative to PCNL in selected cases.

Percutaneous Nephrolithotomy for Stones in Solitary Kidney: Evidence From a Systematic Review

Stones in solitary kidney represent a management dilemma for the endourologist. The advantage of bilateral fully functioning kidneys is not present. Therefore, any insult to either the solitary kidney itself or drainage system can lead to significant morbidity. Key clinical objectives include maximum preservation of existing renal function, high stone clearance, and minimizing post-procedure complications. To date, there exists no Level 1 evidence on this subject. This systematic review serves to evaluate the safety and efficacy of percutaneous nephrolithomy for patients (adults only) with stones in a solitary kidney.

Impact of retrograde flexible ureteroscopy and intracorporeal lithotripsy on kidney functional outcomes

Objective:

The aim of the study was to evaluate renal function and to identify factors associated with renal function deterioration after retrograde intrarenal surgery (RIRS) for kidney stones.

Materials and Methods:

We retrospectively analyzed patients with renal stones treated by RIRS between January 2010 and June 2013 at a single institute. We used the National Kidney Foundation classification of chronic kidney disease (CKD) to classify Glomerular Filtration Rate (GFR) in 5 groups. The baseline creatinine level was systematically pre-operatively and post-operatively evaluated. All patients had a creatinine blood measurement in June 2013. A change toward a less or a more favorable GFR group following RIRS was considered significant.

Results:

We included 163 patients. There were 86 males (52.8%) and 77 females (47.3%) with a mean age of 52.8±17 years. After a mean follow-up of 15.5±11.5 months, median GFR was not significantly changed from 84.3±26.2 to 84.9±24.5 mL/min (p=0.675). Significant renal function deterioration occurred in 8 cases (4.9%) and significant renal function amelioration occurred in 23 cases (14.1%). In univariate analysis, multiple procedures (p=0.023; HR: 5.4) and preoperative CKD (p=0.011; HR: 6.8) were associated with decreased renal function. In multivariate analysis these factors did not remain as predictive factors.

Conclusion:

Stone management with RIRS seems to have favorable outcomes on kidney function; however, special attention should be given to patients with multiple procedures and preoperative chronic kidney disease.

Evaluation of Renal Function after Percutaneous Nephrolithotomy-Does the Number of Percutaneous Access Tracts Matter?

PURPOSE

Renal function following percutaneous nephrolithotomy has long been a concern to urologists, especially in the setting of multi-tract access. We determined whether the risk of renal injury after multi-tract percutaneous nephrolithotomy was greater than after a single access approach.

MATERIALS AND METHODS

We retrospectively reviewed the records of 307 consecutive patients treated with percutaneous nephrolithotomy from 2011 to 2012 at Wake Forest Health. Perioperative (99m)Tc-mercaptoacetyltriglycine nuclear renogram parameters along with serum creatinine values were assessed within 1 year of the procedure. Patients were stratified by single access vs multi-access (2 or more).

RESULTS

We identified 110 cases in which renography was done before and after percutaneous nephrolithotomy. A total of 74 patients (67.3%) underwent single access percutaneous nephrolithotomy while 36 (32.7%) underwent multi-access percutaneous nephrolithotomy. Serum creatinine did not significantly differ between the 2 cohorts postoperatively (p = 0.09). There was a significant 2.28% decrease in renal function based on mercaptoacetyltriglycine nuclear renogram results after percutaneous nephrolithotomy of the affected kidney in patients with multiple accesses (p <0.01). This relationship was not observed when patients were stratified by multiple comorbidities associated with nephrolithiasis.

CONCLUSIONS

Multi-access percutaneous nephrolithotomy is associated with a small reduction in the function of the targeted kidney compared to a single access approach.

Review on renal recovery after anatrophic nephrolithotomy: Are we really healing our patients?

The main goals for urinary stone treatment are to preserve renal function, reduce or avoid complications related to calculi, and to render the patient free of calculi as soon as possible. Anatrophic nephrolithotomy (ANL) is a valid and useful alternative for conventional staghorn calculi excision. Although excellent stone free rates can be achieved with ANL there are some drawbacks that may be of concern. Morbidity related to intraoperative and postoperative complications is one of them. Another, great concern is the possibility of reduction on renal function related to the procedure itself. This may be related to nephron injury during nephrotomy and parenchymal closure or to ischemic injury. In this review we assess functional results after anatrophic nephrolithotomy.

Percutaneous nephrolithotomy in solitary kidneys: experience with 412 cases from Southern Iran

Some patients with nephrolithiasis who become candidates for percutaneous nephrolithotomy (PCNL) have a single kidney. This poses a challenge for the physician regarding the safety and efficacy of this procedure for these patients. This study has aimed to evaluate the safety and efficacy of PCNL in these patients. Between 2002 and 2014, out of 10,800 cases who underwent PCNL in our centres, 412 had a single kidney. We recorded the results and complications in these patients. Out of 412 patients, 279 were men and 133 women. Their mean age was 46.4 years (range 19-71) and mean stone size was 26.5 mm (range 21-55); 161 of them had a functional single kidney, 36 were congenital, and the remaining 215 had undergone contralateral nephrectomy because of stones, trauma, infection or tumour. Comorbidities included 104 hypertensive, 66 diabetic, 65 morbidly obese, 56 uremic and 47 ischemic heart disease cases. The stone-free rate was 91.3% (376/412) on postoperative X-ray/sonography. However, 42 patients required ancillary measures. Complications include fever (T > 38.3 °C) in 34 cases (8.2%), bleeding requiring transfusion 19 cases (4.6%), UTI nine cases (2%), sepsis one case (0.2%), perinephric collection three cases (0.7%), hydro/pneumothorax two cases (0.4%), access failure in five morbidly obese cases (1.2%), pyonephrosis two cases (0.4%), myocardial infarction four cases (1%), transient increasing of blood urea nitrogen (BUN) and serum creatinine (Scr.) in four normal functioning kidney (1%) and eight uremic cases (1.9%), and two cases resulted in death (0.4%). PCNL seems a safe and effective option in cases of a single kidney, but it needs more attention in order to prevent even minor complications that can result in an anephric state.

Laparoscopic stone surgery with the aid of flexible nephroscopy

Purpose

To report the outcome of laparoscopic pyelo- and ureterolithotomies with the aid of flexible nephroscopy.

Materials and Methods

A retrospective analysis was performed in 71 patients with complex renal stones or large and impacted proximal ureteral stones. Patients underwent laparoscopic pyelo- or ureterolithotomies with or without the removal of small residual stones by use of flexible nephroscopy between July 2005 and July 2010. Operative success was defined as no residual stones in the intravenous pyelogram at 12 weeks postoperatively. Perioperative results and surgical outcomes were analyzed.

Results

The patients' mean age was 54.7±13.7 years, and 53 males (74.6%) and 18 females (25.4%) were included. The mean maximal stone size was 19.4±9.4 mm. A total of 47 cases were complex renal stones and 24 cases were impacted ureteral stones. Mean operative time was 139.0±63.7 minutes. Stones were completely removed in 61 cases (85.9%), and no further ancillary treatment was needed for clinically insignificant residual fragments in 7 cases (9.9%). For complex renal stones, the complete stone-free rate and clinically significant stone-free rate were 80.9% and 93.6%, respectively. Multivariate analysis showed that the use of flexible nephroscopy for complex renal stones can reduce the risk of residual stones. A major complication occurred in one case, in which open conversion was performed.

Conclusions

Laparoscopic stone surgery is a safe and minimally invasive procedure with a high success rate, especially with the aid of flexible nephroscopy, and is not associated with procedure-specific complications.