Tubeless procedure is most important factor in reducing length of hospitalization after percutaneous nephrolithotomy: results of univariable and multivariable models

Comparison of standard percutaneous nephrolithotomy and total tubeless percutaneous nephrolithotomy in the supine position

PURPOSE

To compare the efficacy, safety and advantages of the total tubeless (TT) percutaneous nephrolithotomy (PCNL) and standard PCNL in the supine position.

METHODS

This study was carried out at İzmir Tepecik Health Application and Research Center. A total of 87 patients were examined. Forty-three patients who underwent TT procedure were defined as Group 1, and 44 patients who underwent standard procedure with a nephrostomy tube were defined as Group 2. Two techniques were evaluated with demographic data and outcome parameters. Univariate regression analyses were performed in these data sets for the parameters that predicted the TT procedure.

RESULTS

The demographic data of the groups and all characteristics of the stones were similar. When the results were examined, the stone-free rates detected by non-contrast computed tomography (CT) in the postoperative 1st month were similar between the groups. Complication rates and secondary intervention rates were similar. Operation and fluoroscopy times were shorter in group 1, which were not statistically significant. Postoperative hemoglobin decreased, and creatinine values were similar. In Group 1, mean postoperative visual analog scale (VAS) scores and the percentage of VAS reporting > 5 points for pain level measurement were lower and statistically significant. In the univariate analysis of the factors predicting the TT procedure, no significant results were found in any parameter.

CONCLUSION

Performing TT PCNL in the supine position in selected patients reduces postoperative pain without affecting the complication rates as in prone PCNL. Our study is the first to compare TT and standard PCNL in supine position.

Mini-Perc for Renal Stones-A Single Center Experience and Literature Review

AIM

The aim of this study was to analyze the outcomes of miniaturized nephrolithotomy (mini-perc) in the management of renal stones with a diameter smaller than 20 mm.

MATERIALS AND METHODS

We retrospectively reviewed the records of 102 patients who underwent mini-perc between March 2015 and March 2020 in our department. The primary objective was the stone-free rate, but we also analyzed the retreatment rate, complications, hospital stay, operative time and reduction in hemoglobin level. All these patients had this technique as their first-line treatment, in a prone position, using a 16 Fr sheath size. Data were compared to a series of patients from the literature, treated with conventional PCNL.

RESULTS

The patients had calculus limited to either a single calyx or just extending to the renal pelvis, and stone size was less than 20 mm in its maximal dimension. The intrarenal stone location was in the upper calyx in 7 cases, middle calyx in 20 cases and lower calyx in 46 cases, and there were 29 patients with renal pelvis stone. The male to female ratio was 1.5:1, and the median age was 48.4 years. The average stone size was 17.4 mm in diameter (ranging between 9 and 20 mm) and all cases underwent Ho-YaG laser lithotripsy, ballistic energy and combined ultrasonic and ballistic lithotripsy. At the end of the procedure, an antegrade double J stent was placed under fluoroscopy for a maximum of 2 weeks in 42 cases, while 9 cases needed a nephrostomy tube 12-14 F. A total of 51 cases were totally tubeless. Our median operative time was 61 min (ranging from 35 to 75 min). The median hospitalization stay was 3.8 days. The stone free rate was 90.1% after one procedure, only nine (8.8%) cases needed a "second look" flexible ureteroscopy, and the final stone-free rate was 98% (absence of detectable calculi on ultrasound, KUB or non-contrast CT scan). The overall complication rate was 6.86% (Clavien classification I-57.14%; II-28.5%; III-14.2%), while no Clavien IV or V complications were reported. No patient required a blood transfusion, and mean hemoglobin loss was 0.81 mg/dL. Overall, our results are better than similar data for conventional PCNL in the literature.

CONCLUSIONS

The "mini-perc" technique is an effective procedure for the treatment of the renal lithiasis that is less or equal to 2 cm. The results demonstrated that this minimally invasive technique is associated with a higher stone-free rate and minimal complications.

Comparison Between Percutaneous Nephrolithotomy and Retrograde Flexible Nephrolithotripsy in Obese Patients with 2 - 4 cm Renal Stones

Background: Nowadays, because of remarkable advancements in retrograde intrarenal surgery (RIRS), modest attention toward this procedure as the second or alternative choice for renal stones treatment has been drawn. Objectives: In the present study, we compared RIRS and percutaneous nephrolithotomy (PCNL) outcomes in treating obese patients with 2 - 4 cm renal stones. Methods: Eighty-two patients who underwent PCNL (n = 40) and RIRS (n = 42) between June 2015 and December 2018 at the Department of Urology of Sina Hospital were enrolled in our retrospective cohort study. Results: After the first surgery session, stone-free rates for the RIRS group were 92.9% and for the PCNL group was 95% (P value = 0.52). The mean operation time for the RIRS and PCNL groups were 71.6 ± 11 and 93.3 ± 12.2, respectively (P < 0.001). The hospitalization stay for all of the PCNL group was more than 1 day (mean = 2.5 days); however, that for the majority of the RIRS group was less than 1 day (P < 0.001). The analgesic use in the RIRS group was significantly lower than in the PCNL group (9.0 ± 5.5, 61.8 ± 13.6, respectively; P < 0.001). The overall complication rates were higher in the RIRS group. However, none of them were statically significant (P > 0.05). Conclusions: According to satisfactory outcomes obtained in the RIRS groups, it can be concluded that RIRS can be applied as an alternative or even the first choice in obese patients with 2 - 4 cm renal stones.

Worldwide practice patterns of percutaneous nephrolithotomy

PURPOSE

To evaluate the current practice of percutaneous nephrolithotomy (PCNL), conducting a worldwide survey among urologists with a special interest in endo-urology.

METHODS

A 22-question survey was specifically developed by the European Association of Urology (EAU) young academic urologists (YAU) and uro-technology (ESUT) groups and globally distributed via SurveyMonkey to almost 2000 members of Endourology Society. The questionnaire included questions dedicated to the demographics and general practice of the participating urologists.

RESULTS

In total, 441 responses (male/female ratio - 418/23) were received. A comparatively higher percentage of specialists (56.2%) practiced in academic institutions and had specific endo-urological fellowship training (56.7%). The classical prone PCNL remained the most practiced approach among the surveyed specialists, 47.7% stated to always do prone PCNLs, while 51.8% of respondents used multiple positioning options as required. The PCNL tract was mostly performed by urologists (84.3%) and fluoroscopic guidance was still predominantly used by 74.5% of respondents. The most practiced tract dilation method was balloon dilator used by 42% of respondents. Most of the surveyed urologists had ultrasonic, pneumatic or laser lithotripsy devices in their armamentarium. The use of some form of post-procedural drainage was reported in 85.1% of respondents, whereas tubeless PCNL remained a fairly uncommon practice.

CONCLUSION

The majority of urologists still use prone positioning, get their own access under fluoroscopy guidance and use a balloon for tract dilation. However, we also identified that when necessary, urologists will deviate from routine practice and change strategy, adopting other approaches for PCNL.

Predicting the Stone-Free Status of Percutaneous Nephrolithotomy With the Machine Learning System: Comparative Analysis With Guy’s Stone Score and the S.T.O.N.E Score System

Purpose: The aim of the study was to use machine learning methods (MLMs) to predict the stone-free status after percutaneous nephrolithotomy (PCNL). We compared the performance of this system with Guy’s stone score and the S.T.O.N.E score system.

Materials and Methods: Data from 222 patients (90 females, 41%) who underwent PCNL at our center were used. Twenty-six parameters, including individual variables, renal and stone factors, and surgical factors were used as input data for MLMs. We evaluated the efficacy of four different techniques: Lasso-logistic (LL), random forest (RF), support vector machine (SVM), and Naive Bayes. The model performance was evaluated using the area under the curve (AUC) and compared with that of Guy’s stone score and the S.T.O.N.E score system.

Results: The overall stone-free rate was 50% (111/222). To predict the stone-free status, all receiver operating characteristic curves of the four MLMs were above the curve for Guy’s stone score. The AUCs of LL, RF, SVM, and Naive Bayes were 0.879, 0.803, 0.818, and 0.803, respectively. These values were higher than the AUC of Guy’s score system, 0.800. The accuracies of the MLMs (0.803% to 0.818%) were also superior to the S.T.O.N.E score system (0.788%). Among the MLMs, Lasso-logistic showed the most favorable AUC.

Conclusion: Machine learning methods can predict the stone-free rate with AUCs not inferior to those of Guy’s stone score and the S.T.O.N.E score system.

Pediatric Stone Surgery: What Is Hot and What Is Not

PURPOSE OF REVIEW

We aim to highlight recent advances in technology and techniques for surgical management of urinary tract calculi in pediatric patients.

RECENT FINDINGS

Percutaneous nephrolithotomy (PCNL) is classically performed in the prone position. The supine PCNL was first attempted to overcome the shortcomings of difficult airway access, patient and surgeon discomfort. The supine PCNL, and subsequent modifications, has been successfully described in the pediatric population. Classically, PCNL has also been classically concluded with obligate placement of a nephrostomy tube and bladder catheter. Recently, tubeless and totally tubeless PCNL reduces pain and duration of hospitalization with satisfactory surgical outcomes in children. Finally, we describe the use of thulium laser technology, which offers improved efficacy in stone treatment and may supplant the current dominant technologies in coming years. Recent advances in pediatric stone surgery include supine PCNL, miniaturized PCNL instrumentation, tubeless procedures, and thulium laser technology.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Evaluating outcomes of complete supine percutaneous nephrolithotomy for staghorn vs multiple non-staghorn renal stones: a 10-year study

PURPOSE

To evaluate the outcomes of complete supine percutaneous nephrolithotomy (csPCNL) for staghorn stones and multiple large non-staghorn stones.

METHODS

The records of 886 patients who underwent csPCNL from September 2009 to October 2019 were considered. Out of them, 201 cases met the eligibility criteria and they were divided into three groups: 63 cases of staghorn, 68 cases of multiple medium (20 mm < diameter ≤ 30 mm) non-staghorn and 70 cases of multiple large non-staghorn (> 30 mm) stones. Almost all outcomes and stone-related factors were analyzed.

RESULTS

There was not any significant difference regarding age, body mass index, history of urinary tract infection, transfusion rate, complication rate, pre and post-surgery serum creatinine, hemoglobin drop and total hospital stay between the three groups. Stone free rate was 98.5% in multiple medium group, 97.1% in multiple large group and 84.1% in staghorn group (P = 0.001). The operation duration was significantly shorter for the multiple medium group (P < 0.001) but it was not significantly different between the multiple large non-staghorn and staghorn group.

CONCLUSION

The results demonstrated that almost all outcomes were not significantly different between the three groups (especially between staghorn and larger non-staghorn ones). These findings reveal that surgeons could choose csPCNL for treatment of staghorn stones and multiple large non-staghorn stones and consider staghorn stones as challenging as multiple large (especially diameter > 30 mm) non-staghorn stones.

Percutaneous nephrolithotomy versus flexible ureteroscopy in terms of cost-effectiveness in patients with 10-30 mm renal stones

PURPOSE

Kidney stones are one of the most common urological problems. When deciding on the method of treatment for this common disease, the cost of the procedure should also be taken into consideration.

MATERIALS AND METHODS

We performed a retrospective analysis of 55 patients who underwent percutaneous nephrolithotomy and 75 patients who underwent retrograde intrarenal surgery between January 2016 and November 2018. Until operative success was achieved, all additional surgical procedures, extracorporeal shock wave lithotripsy procedures, and interventional procedures required to resolve complications were recorded. Total cost was compared between the percutaneous nephrolithotomy and retrograde intrarenal surgery groups.

RESULTS

No significant difference was found between the percutaneous nephrolithotomy and retrograde intrarenal surgery groups in terms of gender, mean age, stone side, stone localization and stone surface area. The total cost of 55 patients that underwent percutaneous nephrolithotomy was calculated as US$14.766 after the first operation, and the total cost of 75 patients that underwent retrograde intrarenal surgery was determined to be US$46.627. The mean cost per patient was calculated US$320 ± US$186 for percutaneous nephrolithotomy and US$749 ± US$242 for retrograde intrarenal surgery (p < 0.001).

CONCLUSIONS

Percutaneous nephrolithotomy is a lower-cost and successful method in the surgical treatment of 1-3 cm stones, but the serious complications involved in this operation should be kept in mind.

Assessment of lower calyceal single-access percutaneous nephrolithotomy for staghorn stones: A single-surgeon and a single-center experience at KAMC, Riyadh

Introduction:

Percutaneous nephrolithotomy (PCNL) is still the mainstay and the treatment of choice for most complex renal stones. The success of PCNL is defined by achieving a stone-free rate (SFR). Lower calyceal access PCNL is established to be the safest percutaneous access to the renal system, but controversy is present when it comes to SFR in comparison to upper calyceal and middle calyceal accesses.

Aim:

We aim to prove that lower calyceal access PCNL is the safest PCNL access and has the same efficacy as upper calyceal access PCNL for staghorn stones.

Methodology:

All lower calyceal access PCNLs done from May 2012 to August 2017 were included in the study. Postoperative complications were reported using the modified Clavien Grading System.

Results:

Sixty-seven patients were included in the study. The mean age was found to be 49.39 years; most (36 [53.73%]) patients were male. The prevalence of diabetes, hypertension, dyslipidemia, and chronic kidney disease was 40.91%, 47.76%, 37.31%, and 20.00%, respectively. The mean hospital stay was 7.9 days; mean operative time was 138.52 min. The mean staghorn stone burden was 476.34 mm². About 80.59% (n = 54) of patients had complete stone resolution after the first session. Only 3 (4.47%) patients had complications and classified as Grade 2 on the modified Clavien Grading System and the remainder were classified as Grade 1, two patients needed postoperative blood transfusion, and one had a renal pelvis perforation.

Conclusion:

When it comes to safety and efficacy, the use of lower calyceal single-access PCNL has a very low complication rate compared to upper calyceal access PCNL, especially pneumothorax and bleeding.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

"Microperc" micropercutaneous nephrolithotomy: a review of the literature

Recent years have seen innovations in working armamentarium of percutaneous nephrolithotomy (PCNL) leading to development of novel modifications such as miniperc, ultra miniperc, and microperc. Amongst these microperc appears to be least invasive and various authors, off late, have reported their experience with the technique. Literature on microperc was reviewed by a MEDLINE/PubMed search with articles in the English language since 2011 in published peer-reviewed journals. Articles comprised of case series, comparative, and noncomparative studies. Different facets encompassing the technique were analyzed including contemporary indications, technique and its modifications, outcomes, and comparison with other modalities. Technique is reported to be associated with high success rate (82-100%) and short hospital stay (1-2 days). Studies have reported minimal hemoglobin drop (0.1-1.4 gm%) and fewer complications of lower Clavien grades. Going small in PCNL has gone a long way to present day 4.85F puncture system. Utilization of this novel modification is on rise with larger case series and comparative analysis being reported in past 2 years. Technique boasts of high clearance rate, lower morbidity and short hospital stay. In the present era, this innovation in percutaneous stone management appears to be another milestone in quest for "knife to cannula to needle to nothing".

Comparison of the outcomes of complete supine percutaneous nephrolithotomy in patients with radiopaque and radiolucent kidney stones

Objective

This study compared the stone opacity effect in patients who had radiopaque and radiolucent stones in percutaneous nephrolithotomy (PCNL) results.

Material and methods

The medical records of 171 complete supine PCNL procedures were gathered. Patients were categorized into two groups: those with radiopaque (n=141) and those with radiolucent (n=30) stones. Kidney, ureter and bladder x-ray was done a day after PCNL and Ultrasound imaging was done two weeks later to evaluate the stone free rate. A stone free result was defined as having less than 4 mm residual stone size. Outcome parameters were compared by univariate analysis and those which were significantly different between the two groups were assessed by multivariate binary logistic regression analysis.

Results

There were no significant differences in age, sex, body mass index, hypertension, diabetes mellitus, pre-surgery hemoglobin, pre-surgery serum creatinine, stone and also surgery-related parameters between the two groups. Stone free rate, surgery time, complication-related parameters, hemoglobin drop, serum creatinine and glomerular filtration rate (GFR) changes were similar in both groups based on univariate analysis. The radiopaque group had higher post-surgery GFR (p=0.04) and longer hospital stay (p=0.009). However, opacity had no effect on these outcomes after multivariate analysis. Higher post-surgery GFR was seen in patient with higher GFR before surgery (p<0.0001). Also, higher hemoglobin before surgery was correlated with less hospital stay (p=0.001).

Conclusion

The complete supine percutaneous nephrolithotomy outcomes are similar in patients with radiopaque and radiolucent stones.

Intraoperative and postoperative feasibility and safety of total tubeless, tubeless, small-bore tube, and standard percutaneous nephrolithotomy: a systematic review and network meta-analysis of 16 randomized controlled trials

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is performed to treat relatively large renal stones. Recent publications indicate that tubeless and total tubeless (stentless) PCNL is safe in selected patients. We performed a systematic review and network meta-analysis to evaluate the feasibility and safety of different PCNL procedures, including total tubeless, tubeless with stent, small-bore tube, and large-bore tube PCNLs.

METHODS

PubMed, Cochrane Central Register of Controlled Trials, and EMBASE™ databases were searched to identify randomized controlled trials published before December 30, 2013. One researcher examined all titles and abstracts found by the searches. Two investigators independently evaluated the full-text articles to determine whether those met the inclusion criteria. Qualities of included studies were rated with Cochrane's risk-of-bias assessment tool.

RESULTS

Sixteen studies were included in the final syntheses including pairwise and network meta-analyses. Operation time, pain scores, and transfusion rates were not significantly different between PCNL procedures. Network meta-analyses demonstrated that for hemoglobin changes, total tubeless PCNL may be superior to standard PCNL (mean difference [MD] 0.65, 95% CI 0.14-1.13) and tubeless PCNLs with stent (MD -1.14, 95% CI -1.65--0.62), and small-bore PCNL may be superior to tubeless PCNL with stent (MD 1.30, 95% CI 0.27-2.26). Network meta-analyses also showed that for length of hospital stay, total tubeless (MD 1.33, 95% CI 0.23-2.43) and tubeless PCNLs with stent (MD 0.99, 95% CI 0.19-1.79) may be superior to standard PCNL. In rank probability tests, small-bore tube and total tubeless PCNLs were superior for operation time, pain scores, and hemoglobin changes.

CONCLUSIONS

For hemoglobin changes, total tubeless and small-bore PCNLs may be superior to other methods. For hospital stay, total tubeless and tubeless PCNLs with stent may be superior to other procedures.

Intraoperative and postoperative feasibility and safety of total tubeless, tubeless, small-bore tube, and standard percutaneous nephrolithotomy: a systematic review and network meta-analysis of 16 randomized controlled trials

Background

Percutaneous nephrolithotomy (PCNL) is performed to treat relatively large renal stones. Recent publications indicate that tubeless and total tubeless (stentless) PCNL is safe in selected patients. We performed a systematic review and network meta-analysis to evaluate the feasibility and safety of different PCNL procedures, including total tubeless, tubeless with stent, small-bore tube, and large-bore tube PCNLs.

Methods

PubMed, Cochrane Central Register of Controlled Trials, and EMBASE™ databases were searched to identify randomized controlled trials published before December 30, 2013. One researcher examined all titles and abstracts found by the searches. Two investigators independently evaluated the full-text articles to determine whether those met the inclusion criteria. Qualities of included studies were rated with Cochrane’s risk-of-bias assessment tool.

Results

Sixteen studies were included in the final syntheses including pairwise and network meta-analyses. Operation time, pain scores, and transfusion rates were not significantly different between PCNL procedures. Network meta-analyses demonstrated that for hemoglobin changes, total tubeless PCNL may be superior to standard PCNL (mean difference [MD] 0.65, 95% CI 0.14–1.13) and tubeless PCNLs with stent (MD -1.14, 95% CI -1.65–-0.62), and small-bore PCNL may be superior to tubeless PCNL with stent (MD 1.30, 95% CI 0.27–2.26). Network meta-analyses also showed that for length of hospital stay, total tubeless (MD 1.33, 95% CI 0.23–2.43) and tubeless PCNLs with stent (MD 0.99, 95% CI 0.19–1.79) may be superior to standard PCNL. In rank probability tests, small-bore tube and total tubeless PCNLs were superior for operation time, pain scores, and hemoglobin changes.

Conclusions

For hemoglobin changes, total tubeless and small-bore PCNLs may be superior to other methods. For hospital stay, total tubeless and tubeless PCNLs with stent may be superior to other procedures.

How practical is the application of percutaneous nephrolithotomy scoring systems? Prospective study comparing Guy's Stone Score, S.T.O.N.E. score and the Clinical Research Office of the Endourological Society (CROES) nomogram

Objective

To prospectively compare the Guy’s Stone Score (GSS), S.T.O.N.E. [stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence or stone density (E)] score and the Clinical Research Office of the Endourological Society (CROES) nephrolithometric nomogram to predict percutaneous nephrolithotomy (PCNL) success rate and assess the correlation with perioperative complications.

Patients and methods

We prospectively evaluated all consecutive PCNL patients at our institute between 1 November 2013 and 31 May 2015. The above scoring systems were applied to preoperative non-contrast computed tomography and the practical difficulties in such applications were noted. Perioperative complications and the stone-free rate (SFR) were also recorded. Receiver operating characteristic curves were drawn and the areas under curves were compared and appropriate statistical analysis done.

Results

In all, 48 renal units were included in the study. The overall SFR was 62.2%. The presence of staghorn stones (β = 27.285, 95% confidence interval 1.19–625.35; P = 0.039) was the only significant variable associated with the residual stones on multivariate analysis. Stone-free patients had significantly lower median GSS (2 vs 4) and S.T.O.N.E. scores (6 vs 10) and higher median CROES scores (83% vs 63%) (all P < 0.001) compared to residual-stone patients. All scoring systems were significantly associated with SFR (all P < 0.001). There was no significant difference in the areas under curves of the scoring systems (0.858, 0.923, and 0.931, respectively). Furthermore, all scoring systems had weak correlations with Clavien–Dindo classified complications (r = 0.29, P = 0.045; r = 0.40, P = 0.005 and r = −0.295, P = 0.04, respectively). We found no standardisation for the measurement of stone dimensions, tract length, Hounsfield units, and staghorn definition.

Conclusions

All scoring systems equally predicted SFR and had a weak correlation with Clavien–Dindo complications. Standardisation is needed for the variables in which they have been found deficient.

Kidney stones

Kidney stones are mineral deposits in the renal calyces and pelvis that are found free or attached to the renal papillae. They contain crystalline and organic components and are formed when the urine becomes supersaturated with respect to a mineral. Calcium oxalate is the main constituent of most stones, many of which form on a foundation of calcium phosphate called Randall's plaques, which are present on the renal papillary surface. Stone formation is highly prevalent, with rates of up to 14.8% and increasing, and a recurrence rate of up to 50% within the first 5 years of the initial stone episode. Obesity, diabetes, hypertension and metabolic syndrome are considered risk factors for stone formation, which, in turn, can lead to hypertension, chronic kidney disease and end-stage renal disease. Management of symptomatic kidney stones has evolved from open surgical lithotomy to minimally invasive endourological treatments leading to a reduction in patient morbidity, improved stone-free rates and better quality of life. Prevention of recurrence requires behavioural and nutritional interventions, as well as pharmacological treatments that are specific for the type of stone. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more-effective drugs.

Metal telescopic and Amplatz sheath dilation in nephrolithotomy

INTRODUCTION

Comparison of Amplatz sheath percutaneous nephrolithotomy (Amplatz PCNL) and metal telescopic dilation PCNL (MTD PCNL) with respect to clinical outcomes and complications.

MATERIALS AND METHODS

Single-institution retrospective chart review with 73 patients who underwent PCNL divided into two groups: Amplatz PCNL (n = 26) and MTD PCNL (n = 47). Efficacy (stone-free rate, residual stones, and surgical duration) and safety (transfusion rate and hemoglobin decrease) were evaluated. Complications were recorded and classified using the modified Clavien classification system.

RESULTS

The two PCNL groups were similar regarding mean age, stone burden, side, stone location, and stone composition. There were no significant differences in surgery duration (101 ± 28 vs. 98 ± 30 min; P = 0.906), transfusion rate (3.9% vs. 4.3%; P = 0.382), and hemoglobin drop (0.9 ± 0.9 vs. 1 ± 0.7 g/dl; P = 0.424) for Amplatz and MTD PCNL, respectively. Stone-free rate (86% vs. 68%; P = 0.001) was significantly higher while residual fragments rate (37% vs. 60%; P = 0.001) was significantly lower in Amplatz PCNL compared to MTD PCNL. However, tube stay time (4.4 ± 1.8 vs. 5.8 ± 3.6 days; P = 0.005) and hospital time (8.6 ± 2.6 vs. 9.7 ± 5.5 days; P = 0.0001) were significantly longer in Amplatz PCNL compared to MTD PCNL. Clavien grading revealed a significantly higher rate of low-grade complications (I-III) for the MTD PCNL in comparison to Amplatz PCNL (10.6% vs. 3.9%, respectively; P = 0.011). There were no major complications and no tract dilation failure.

CONCLUSION

The study demonstrates that Amplatz PCNL is a safe and effective procedure to remove large renal stones compared with MTD PCNL.

'Mini, ultra, micro' - nomenclature and cost of these new minimally invasive percutaneous nephrolithotomy (PCNL) techniques

New minimally invasive percutaneous nephrolithotomy (PCNL) techniques have changed the management of renal stones. We discuss the technological advances in PCNL and explain the meaning, requirements and set up costs for each of these 'newer' techniques.

Comparison of retrograde intrarenal surgery and percutaneous nephrolithotomy for the treatment of renal stones greater than 2 cm

OBJECTIVE

To evaluate the safety and efficacy of retrograde intrarenal surgery (RIRS) in the treatment of kidney stones greater than 2 cm and to compare its results with those of percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

We retrospectively analyzed a total of 143 patients: 86 patients (53 males and 33 females) who underwent PCNL and 57 patients (37 males and 20 females) who underwent RIRS between October 2009 and October 2013.

RESULTS

The mean duration of operation was 100.26±33.26 min in the RIRS group and 75.55±21.5 min in the PCNL group (p<0.001). The hospital stay was significantly shorter in the RIRS group (1.56±0.8 vs. 4.57±2.1 days in the RIRS and PCNL groups, respectively; p<0.001). Stone-free rates after one session were 66.6% and 91.8% of the RIRS and PCNL groups, respectively. The stone-free rate of the RIRS group improved to 87.7% after the second session. Blood transfusions were required in two patients in the PCNL group. Complication rates were higher in the PCNL group.

CONCLUSION

This study revealed that RIRS can be an alternative to PCNL in the treatment of kidney stones with a diameter of 2-4 cm especially in patients with comorbidities.

Intraoperative patient selection for tubeless percutaneous nephrolithotomy

This study was conducted to report our experience of intraoperative patient selection for tubeless percutaneous nephrolithotomy (PCNL) based on a tentative decision-making algorithm. Thirty-four consecutive patients who were scheduled to undergo tubeless PCNL were included and medical records were obtained from a prospectively maintained database for these patients. After completion of PCNL, the nephrostomy site was observed with a safety guidewire in place. If there was no significant bleeding through the tract, tubeless PCNL was performed, and in cases with significant bleeding or other complications, nephrostomy catheter insertion was performed as usual. In 29 cases (85.3%), tubeless PCNL was performed according to our decision-making protocol. Mean stone size was 7.33 ± 9.35 cm(2). Mean hospital stay was 2.61 ± 1.01 days. The difference between preoperative and postoperative hemoglobin was 0.68 ± 1.22 g/dL (p > 0.05). Visual analog pain scale scores immediately post-operation, on postoperative day one and on the day of discharge were 4.62 ± 1.80, 3.25 ± 1.68 (postoperative day one vs. operative day; p = 0.001), and 1.87 ± 0.83 (the day of discharge vs. operative day; p = 0.001), respectively. The success rate with insignificant remnant stones was 85.2% and complete stone-free rate was 76.5%. In conclusion, tubeless PCNL was performed successfully with low complication rate and reduced pain score through our decision-making algorithm.

Micropercutaneous nephrolithotomy. A new therapeutic option for pediatric renal lithiasis

INTRODUCTION

Micropercutaneous nephrolithotomy is an evolution from the conventional percutaneous surgery in which pyelocaliceal access is obtained through minimum bore holes. Its objective is the complete removal of the calculi, lowering the morbidity associated with larger bore percutaneous tracts.

MATERIAL AND METHODS

We present the case of a micropercutaneous nephrolithotomy performed in a 14-year-old female patient with a 35 mm diameter kidney stone located in the renal pelvis. Surgery was performed in the Galdakao-modified supine Valdivia position. Puncture was done under ultrasound and fluoroscopic guidance. The 4.85 Ch needle of the Microperc(®) set was used, completing the procedure through the 8 Ch working shaft. Lasertripsy was done with the Ho:YAG laser. An indwelling double J stent was placed at the end of the procedure.

RESULTS

Operating time was 170 minutes. Hospital stay was one day. She suffered renal colic after 72 hours, which was resolved with oral analgesic treatment at home (Clavien I). She returned to school on the fifth postoperative day. The double J was removed at 2 weeks. At one month of the surgery, the patient is asymptomatic, a 4mm lower calyx residual stone being observed in the abdominal ultrasound.

CONCLUSION

Micropercutaneous nephrolithotomy is a step forward towards the search for a less invasive kidney stone treatment. It is a safe and effective technique in the pediatric population, and it can be performed in the supine position, even in orthotropic kidneys. Future studies and collaborative works will help to better define its indications, to optimize its technique and to analyze its cost-effectiveness compared with other treatment options.

Tubeless percutaneous nephrolithotomy: outcomes with expanded indications

INTRODUCTION

Tubeless PCNL has been utilized to shorten hospital stay and improve patient postoperative pain control. Prior studies have excluded those patients with significant bleeding or other complications. Our objective was to evaluate the utility of tubeless PCNL in all patients irrespective of intraoperative outcome.

MATERIALS AND METHODS

A retrospective review of the charts of patients who underwent PCNL at our institute was performed. Patients were assigned to one endourologist Who routinely performed tubeless PCNL and to a second endourologist who routinely left a small-bore pigtail nephrostomy. Preoperative demographics operative and postoperative outcomes were compared.

RESULTS

Out of 159 patients included, 83 patients had tubeless PCNL while 76 patients had standard PCNL. There was no difference between groups regarding age, gender, ASA score, number, maximum diameter of stones, number of calyces involved, Stone density (HU), laterality and use of preoperative narcotics. While staghorn stones were more common in patients who underwent standard PCNL (p = 0.008). Tubeless patients had less number of access tracts (p ≤ 0.001), shorter hospital stay (1.7 vs. 3.0 days, p = 0.001) when compared to standard PCNL group. Multivariable analysis controlling for confounding factors including staghorn calculi and number of accesses confirmed that tubeless PCNL was associated with shorter hospital stay and less postoperative pain. There was no significant difference in complication rates between the two groups.

CONCLUSION

Our report confirms the previous reports of shorter hospital stay, less pain and analgesia as compared to standard PCNL, and establishes its safety irrespective of bleeding, perforation, extravasation or other intraoperative issues that have previously been utilized as exclusionary criteria for this approach.

Factors Influencing the Duration of Urine Leakage following Percutaneous Nephrolithotomy

Purpose. The duration of urine leakage following the removal of the nephrostomy tube after percutaneous nephrolithotomy (PCNL) shows significant variations depending on the techniques used. We aimed to assess the factors likely to influence the duration of urine leakage. Material and Methods. In total, 103 patients who underwent PCNL were reviewed retrospectively. DUL was evaluated regarding patient characteristics, thickness of the access line, presence of hydronephrosis, and residual stones. Results. DUL was significantly prolonged in accordance with a decrease in the thickness of parenchyma tissue (R = −0.716, P < 0.001). DUL was prolonged as the degree of hydronephrosis (R = 0.526, P < 0.001) and the number of patients with residual stones (R = 0.273, P = 0.005) increased. Median DUL was significantly longer in patients with residual stones than those without residual stones (P = 0.002). In the receiving operating curve analysis, the optimum cut-off value of parenchymal thickness for hospitalization ≤12 h was 17.2 mm (sensitivity, 90.2%; specificity, 69.4%; P = 0.001). Conclusions. We found that parenchymal thickness of the access line, hydronephrosis, and residual stones were the most influential factors determining DUL following PCNL, respectively.

Initial experience of micro-percutaneous nephrolithotomy in the treatment of renal calculi in 140 renal units

The aim of this study was to investigate the effectiveness and reliability of the micro-percutaneous nephrolithotomy (PNL) method for the management of kidney stones. We performed a retrospective analysis of 136 patients (140 renal units) who underwent micro-PNL for renal stones between September 2011 and February 2013 in four referral hospitals in Turkey. The selection of treatment modality was primarily based on factors such as stone size and location. In this study, we analyzed patient- and procedure-related factors. The mean age of patients in this study was 28.7 ± 20.6 (1-69) years, and the mean stone size was 15.1 ± 5.15 (6-32) mm. Conversion to mini-PNL was required in 12 patients. All interventions were performed with the patient in the prone position, except for the 3-year-old patient with the pelvic kidney who was placed in the supine position. The mean hospital stay was 1.76 ± 0.65 (1-4) days, and the mean drop in the hemoglobin level was 0.87 ± 0.84 (0-4.1) mg/dL. One of our patients required transfusion. Ureteral J stent was implanted in nine (6.43 %) patients because of residual stones. Seven (6.43 %) patients complained of postoperative renal colic which was managed conservatively. Abdominal distension related to extravasation of the irrigation fluid was observed in three patients (2.19 %). There were no other postoperative complications. An overall success rate of 82.14 % was achieved. Micro-PNL can be effectively and safely used for small and moderate kidney stones resistant to shock wave lithotripsy or as an alternative to other minimally invasive treatment methods.

Tubeless procedure reduces hospitalization and pain after percutaneous nephrolithotomy: results of a multivariable analysis

The objective of the study was to assess the efficacy and safety of tubeless percutaneous nephrolithotomy (t-PCNL) in comparison with standard PCNL (s-PCNL). We retrospectively evaluated 317 consecutive PCNL and compared perioperative results, time of hospitalization and analgesic requirement of t-PCNL (114; 36.0 %) to s-PCNL (203; 64.0 %). The decision to perform a tubeless PCNL was made at the end of the procedures depending on the surgeon's preference and according to the following inclusion criteria: (a) no serious bleeding or perforation in the collecting system during the procedure; (b) patients with no more than one access; and (c) residual stone burden needing a second-stage nephroscopy. Staghorn stones and anatomic anomalies were not considered as exclusion criteria for t-PCNL. Univariate analyses were conducted with one-way ANOVA, Fisher's exact test, Pearson's Chi-square and linear-by-linear association test as appropriate. Stepwise multivariable regression analyses were used to assess the independent correlation between demographics and clinical variables and the clinical outcomes. There were no significant differences between the two groups in terms of stone-free rate, hemoglobin decrease, blood transfusion and complication rate. Mean hospital stay was significantly shorter in the t-PCNL group (3.3 vs. 4.6 days; P < 0.001). Tubeless PCNL was associated with less analgesia requirement (68.4 vs. 86.7 %; P < 0.001) and with lower analgesic dose requirement (1.6 vs. 2.1 mean doses; P = 0.010). Multivariable analyses showed that t-PCNL (P < 0.001), postoperative fever (P < 0.001), transfusions (P < 0.001), operative time (P = 0.002), postoperative hydronephrosis (P = 0.005) and residual fragment dimension (P = 0.024) were independently correlated with duration of hospitalization, while analgesic dose requirement was independently influenced by hemoglobin decrease (P < 0.001), t-PCNL (P = 0.005) and stone number (P = 0.044). Our study confirmed that t-PCNL has similar outcomes to s-PCNL in terms of stone-free rate without increasing complications in selected cases. t-PCNL is a factor independently associated with shorter hospitalization and lower analgesic requirement.

Micropercutaneous nephrolithotomy in the treatment of moderate-size renal calculi

PURPOSE

We present our initial experience with microperc in patients with moderate-size renal calculi.

PATIENTS AND METHODS

A retrospective analysis of 30 patients (male 14, female 16) with moderate-size (1-3 cm) kidney stones who underwent microperc between August 2011 and July 2012 was performed. The demographic values, perioperative and postoperative measures including age, stone size and location, body mass index, operative and fluoroscopy time, hemoglobin decrease, success and complication rates were prospectively recorded into a patient entry system.

RESULTS

The average stone size was 17.9±5.0 mm (10-30 mm). The mean age of the patients was 41.5±18.2 years (range 3-69 years). The duration of the operation was calculated as 63.5±36.8 minutes (range 20-200 min). Mean fluoroscopic screening time was 150.5±90.4 seconds (range 45-360 seconds). The patients were discharged after a mean hospitalization period of 35.5±18.6 hours (range 14-96 hours). An overall success rate of 93% (including 10% of insignificant residual fragment rate) was achieved. In the follow-up, residual stone fragments were detected in two (7%) patients. Conversion to miniperc was necessitated in three (10%) patients. The mean hemoglobin drop was found to be 1.1±0.8 mg/dL (range 0-2.8 mg/dL). Complications were observed in five (13.3%) patients.

CONCLUSIONS

Our initial results provide that microperc is a feasible, safe, and efficacious treatment modality for moderate-size kidney stones as well as small ones with its minimally invasive nature. Technical refinements are needed to achieve better results and overcome the limitations of technique.

Cost-effectiveness treatment strategies for stone disease for the practicing urologist

Kidney stone disease is rising in prevalence in the United States and abroad, and the cost burden of this condition is substantial. Although cost-effectiveness considerations are typically made by policymakers, individual practitioners have become increasingly involved in these discussions, to affect the rising costs of care and to assert control of treatment options. This article reviews existing literature regarding the cost-effectiveness of medical and surgical treatments for stone disease and identifies areas in which additional investigation is needed.

Chinese minimally invasive percutaneous nephrolithotomy for intrarenal stones in patients with solitary kidney: a single-center experience

OBJECTIVE

To report our experience with Chinese minimally invasive percutaneous nephrolithotomy (Chinese MPCNL) to manage patients with intrarenal stones in solitary kidney, and evaluate the safety, efficiency and feasibility of this technique.

METHODS

Forty-one patients with intrarenal stones in solitary kidney underwent Chinese MPCNL in our department from March 2009 to February 2011. Demographic characteristics, operative parameters, number of tracts, stone-free rates (SFRs), stone analyses, hemoglobin levels, nephrostomy tube removal time, hospitalization time, and complications were evaluated. Serum creatinine (Scr) and glomerular filtration rate (GFR) were measured preoperatively, postoperatively at 1 month, and each follow-up visit. The 5-stage classification of chronic kidney disease (CKD) was used according to the National Kidney Foundation guidelines.

RESULTS

The initial stone-free status was achieved in 35 (85.4%) patients after Chinese MPCNL. The mean follow-up time was 16.9 ± 4.7 months (range: 12-24), and the final SFR improved to 97.6% after auxiliary procedures. Among all patients, complex stones were detected in 26 (63.4%) patients, and 9 (22.0%) required multiple tracts. The mean operative time and mean hospitalization time were 71.3 ± 23.5 min (range: 40-139) and 6.1 ± 0.5 days (range: 5-11), respectively. During preoperative period and postoperative period (1 month), Scr were 132.1 ± 41.3 umol/L (range: 78.2-231.4) and 108.9 ± 30.7 umol/L (range: 71.6-136.9), respectively (P<0.05), while GFR were 74.9 ± 24.2 ml/min (range: 35-110) and 83.9 ± 27.4 ml/min (range: 65-110), respectively (P<0.05). According to CKD classification, the renal function was stable, improved, and worse in 29 (70.7%), 11 (26.8%), and 1 (2.5%) patients, compared with the preoperative levels. No patient progressed to end-stage renal disease requiring dialysis.

CONCLUSIONS

Our experience with Chinese MPCNL demonstrates that it is safe, feasible and efficient for managing the intrarenal calculi in solitary kidney with a low complication rate. At long-term follow-up, renal function stabilized or even improved in the majority of patients with solitary kidney.

Impact of percutaneous renal access technique on outcomes of percutaneous nephrolithotomy

BACKGROUND AND PURPOSE

Percutaneous nephrolithotomy (PCNL) is regarded as the gold standard for the treatment of patients with renal stones larger than 2 cm in diameter. Creating a percutaneous renal access is the initial and probably the most important step in performing a PCNL. Two primary methods of obtaining proper percutaneous renal access under fluoroscopic guidance are described: The "triangulation" and the "eye of the needle" techniques. In this article, we compare these two techniques in terms of success and complication rates.

PATIENTS AND METHODS

From October 2010 to May 2011, 80 patients with simple renal stones were prospectively randomized into two groups according to the percutaneous renal access technique used for PCNL. Patients in group 1 (n=40) were assigned to the eye of the needle technique, and patients in group 2 (n=40) were assigned to the triangulation method. Patients needing multiple access points were excluded from the study. The preoperative, operative, and postoperative follow-up findings were thereafter analyzed and compared.

RESULTS

No significant difference between the two groups was detected in terms of patient demographics (mean patient age, body mass index, stone size, or stone location). The operation time, fluoroscopic screening time (FST), and duration of hospitalization were similar in both groups (P=0.52, P=0.32, P=0.26, respectively). Patients in group 1 had a larger drop in hematocrit postoperatively than patients in group 2 (7.6 ± 3.7 vs 4.8 ± 2.1, P=0.001). The blood transfusion rate (7.5%) was similar in both groups, however. Although the complication rate was higher in group 1 than group 2, no significant difference was detected (20% vs 15%, P=0.76).

CONCLUSIONS

The present study demonstrates that PCNL can be performed safely using two different percutaneous access techniques. The two techniques studied in this trial had similar FSTs, operation and hospitalization times, success rates, and complication rates.

Outcomes of retrograde intrarenal surgery compared with percutaneous nephrolithotomy in elderly patients with moderate-size kidney stones: a matched-pair analysis

PURPOSE

The aim of our study was to evaluate the outcomes of retrograde intrarenal surgery (RIRS) in elderly patients with stones of moderate size.

PATIENTS AND METHODS

Between September 2008 and June 2011, a total of 28 patients over 65 years of age with single renal stones that measured 1.5 to 3 cm were treated with RIRS. The outcomes of these patients were compared with those of the patients who underwent percutaneous nephrolithotomy (PCNL) using matched-pair analysis (1:1 scenario). The matching parameters were the size and location of the stone as well as age, sex, body mass index, degree of hydronephrosis, presence of previous shockwave lithotripsy, and open surgery. SPSS version 16 was used for statistical analysis.

RESULTS

Stone-free rates after a single procedure were achieved in 82.1% of patients for the RIRS and 92.8% of patients for the PCNL group. The second flexible ureterorenoscopy procedure was performed for five patients in the RIRS group. Finally, stone-free rates during the third month of the follow-up period were 92.8% in the RIRS group and 96.4% in the PCNL group. The mean operative time per patient was 64.5 ± 20.9 minutes in the RIRS group after a total of 33 procedures, while it was 40.7 ± 10.7 minutes in the PCNL groups (P<0.0001). The overall complication rates for the RIRS and PCNL groups were 7.1% and 10.7%, respectively. Blood transfusions were needed in two patients in the PCNL group. Hospitalization time was significantly shorter in the RIRS group (26.5 ± 10.6 h per patient vs 60.0 ± 28.8 h; P<0.0001). In both groups, stones were most frequently composed of calcium oxalate (68.4% in the RIRS group and 77.7% in the PCNL group).

CONCLUSION

RIRS has a low complication rate and represents a safe and effective treatment alternative in selected geriatric patients with kidney stones of moderate size.

Fifty ways to reduce length of stay: an inventory of how hospital staff would reduce the length of stay in their hospital

PURPOSE AND SETTING

In this study we present a bottom up approach to developing interventions to shorten lengths of stay. Between 1999 and 2009 we applied the approach in 21 Dutch clinical wards in 12 hospitals. We present the complete inventory of all interventions.

DESIGN

We organised, on the hospital ward level, structured meetings with the staff in order to first identify barriers to reduce the length of stay and then later to link them to interventions. The key components of the approach were a benchmark with the fifteenth percentile and the use of a matrix, that on one side was arranged along the main phases of the care process--the admission, stay and discharge--and on the other side to the degree to which the length of stay could be shortened by the medical specialists and nurses themselves or by involving others.

FINDINGS AND CONCLUSIONS

The matrix consists of a wide variety of interventions that mainly cover what we found in published research. As a bottom up approach is more likely to succeed, we would advise wards that have to reduce length of stay to make the inventory themselves, using appropriate benchmark data, and by using the matrix.

Incidence, prevention, and management of complications following percutaneous nephrolitholapaxy

CONTEXT

Incidence, prevention, and management of complications of percutaneous nephrolitholapaxy (PNL) still lack consensus.

OBJECTIVE

To review the epidemiology of complications and their prevention and management.

EVIDENCE ACQUISITION

A literature review was performed using the PubMed database between 2001 and May 1, 2011, restricted to human species, adults, and the English language. The Medline search used a strategy including medical subject headings (MeSH) and free-text protocols with the keywords percutaneous, nephrolithotomy, PCNL, PNL, urolithiasis, complications, and Clavien, and the MeSH terms nephrostomy, percutaneous/adverse effects, and intraoperative complications or postoperative complications.

EVIDENCE SYNTHESIS

Assessing the epidemiology of complications is difficult because definitions of complications and their management still lack consensus. For a reproducible quality assessment, data should be obtained in a standardized manner, allowing for comparison. An approach is the validated Dindo-modified Clavien system, which was originally reported by seven studies. No deviation from the normal postoperative course (Clavien 0) was observed in 76.7% of PNL procedures. Including deviations from the normal postoperative course without the need for pharmacologic treatment or interventions (Clavien 1) would add up to 88.1%. Clavien 2 complications including blood transfusion and parenteral nutrition occurred in 7%; Clavien 3 complications requiring intervention in 4.1.%; Clavien 4, life-threatening complications, in 0.6%; and Clavien 5, mortality, in 0.04%. High-quality data on complication management of rare but potentially debilitating complications are scarce and consist mainly of case reports.

CONCLUSIONS

Complications after PNL can be kept to a minimum in experienced hands with the development of new techniques and improved technology. A modified procedure-specific Clavien classification should be established that would need to be validated in prospective trials.

Does pelvicaliceal system anatomy affect success of percutaneous nephrolithotomy?

OBJECTIVE

To investigate the effect of the pelvicaliceal system (PCS) anatomy on the percutaneous nephrolithotomy (PCNL) success rate. Although the caliceal anatomy is effective for stone clearance after shock wave lithotripsy and retrograde intrarenal lithotripsy, the effect of the caliceal anatomy after PCNL has not been evaluated to date.

METHODS

A total of 498 patients who had undergone PCNL and preoperative intravenous urography were enrolled in our study. Kidney-related anatomic factors, such as the PCS surface area and type, degree of hydronephrosis, infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were calculated using intravenous urography. The association between the PCNL success rate and kidney-related anatomic factors was retrospectively analyzed using chi-square tests, Fisher's exact test, Mann-Whitney U test, and forward stepwise regression analysis.

RESULTS

A success rate of 78.1% was achieved. No difference was seen the success rates among the PCS types. The mean PCS surface area was 20.1 ± 9.7 cm(2) in patients with successful outcomes and 24.5 ± 10.2 cm(2) in patients with remaining stones (P = .001). The mean infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were similar in both groups. Multivariate binary logistic regression analysis showed that stone configuration and PCS surface area were independent factors affecting the PCNL success rates.

CONCLUSION

The results of our study have shown that the PCS surface area is the only anatomic factor that affects the PCNL success rate and patients with a PCS surface area <20.5 cm(2) have greater PCNL success.