Perioperative and long-term results of ultrasonography-guided single-and multiple-tract percutaneous nephrolithotomy for staghorn calculi

BACKGROUND It is possible that this condition will lead to urosepsis and progressive deterioration of renal function in the absence of surgical intervention.Several recent clinical studies have shown that multi-tract percutaneous nephrolithotomy(MPCNL)has a similar stone free rate(SFR)as standard percutaneous nephrolithotomy(S-PCNL).As a result,M-PCNL was also recommended as a treatment option for staghorn calculi.AIM To examine the perioperative and long-term results of ultrasonography-guided single-and M-PCNL.METHODS This was a retrospective cohort study.Between March 2021 and January 2022,the urology department of our hospital selected patients for the treatment of staghorn calculi using percutaneous nephrolithotomy.The primary outcomes were com plication rate and SFR,and the characteristics of patients,operative parameters,laboratory measurements were also collected.RESULTS In total,345 patients were enrolled in the study(186 in the S-PCNL group and 159 in the M-PCNL group).The SFR in the M-PCNL group was significantly higher than that in the S-PCNL group(P=0.033).Moreover,the incidence rates of hydrothorax(P=0.03)and postoperative infection(P=0.012)were higher in the M-PCNL group than in the S-PCNL group.Logistic regression analysis demonstrated that post-operative white blood cell count(OR=2.57,95%CI:1.90-3.47,P<0.001)and stone size(OR=1.59,95%CI:1.27-2.00,P<0.001)were associated with a higher overall complication rate in the S-PCNL group.Body mass index(OR=1.22,95%CI:1.06-1.40,P=0.004)and stone size(OR=1.70,95%CI:1.35-2.15,P<0.001)were associated with increased overall complications in the M-PCNL group.CONCLUSION Multiple access tracts can facilitate higher SFR while slightly increasing the incidence of acceptable complications.

Metabolic syndrome and the urinary microbiome of patients undergoing percutaneous nephrolithotomy

Objective:To identify possible stone-promoting microbes,we compared the profiles of microbes grown from stones of patients with and without metabolic syndrome(MetS).The association between MetS and urinary stone disease is well established,but the exact pathophysiologic relationship remains unknown.Recent evidence suggests urinary tract dysbiosis may lead to increased nephrolithiasis risk.Methods:At the time of percutaneous nephrolithotomy,bladder urine and stone fragments were collected from patients with and without MetS.Both sample types were subjected to expanded quantitative urine culture(EQUC)and 16 S ribosomal RNA gene sequencing.Results:Fifty-seven patients included 12 controls(21.1%)and 45 MetS patients(78.9%).Both cohorts were similar with respect to demographics and non-MetS comorbidities.No controls had uric acid stone composition.By EQUC,bacteria were detected more frequently in MetS stones(42.2%)compared to controls(8.3%)(p=0.041).Bacteria also were more abundant in stones of MetS patients compared to controls.To validate our EQUC results,we performed 16 S ribosomal RNA gene sequencing.In 12/16(75.0%)sequence-positive stones,EQUC reliably isolated at least one species of the sequenced genera.Bacteria were detected in both“infectious”and“non-infectious”stone compositions.Conclusion:Bacteria are more common and more abundant in MetS stones than control stones.Our findings support a role for bacteria in urinary stone disease for patients with MetS regardless of stone composition.

The global,prevalence,and risk factors of postoperative fever after percutaneous nephrolithotomy:A systematic review and meta-analysis

Objective:This study aimed to explore the global,prevalence,and risk factors of fever after percutaneous nephrolithotomy(PCNL)by conducting a systematic review and meta-analysis.Methods:The high-sensitivity searching was conducted without time limitation until December 30,2020 in Web of Sciences,Scopus,and PubMed based on inclusion and exclusion criteria.Results:The prevalence rates of fever and sepsis among patient undergoing PCNL were estimated 9.5%(95%confidence interval[CI]:9.3%-9.7%),and 4.5%(95%CI:4.2%-4.8%),respectively.Nephrostomy tube was used in 9.96%(95%CI:9.94%-9.97%)of patients.The mean preoperative white blood cells of patients were 6.401×109/L;18.3%and 4.55%of patients were considered as the positive urinary culture and pyuria,respectively.About 20.4%of patients suffered from residual stones.The odds ratios(ORs)of fever in patients who suffering from diabetes mellitus,hydronephrosis,staghorn stones,and blood transfusion were 4.62(95%CI:2.95-7.26),1.04(95%CI:0.81-1.34),2.57(95%CI:0.93-7.11),and 2.65(95%CI:1.62-4.35),respectively.Patients who underwent PCNL in prone position were more likely to develop fever(OR:1.23;95%CI:0.75-2.00)than patients in supine position.Conclusion:The current study showed that patients who suffer from diabetes mellitus,hydronephrosis,staghorn stones,nephrostomy tube or double-J stent,blood transfusion,and also patients who underwent PCNL in prone position surgery are more likely to develop a postoperative fever after PCNL.

Predictive factors for percutaneous nephrolithotomy bleeding risks

Objective:This study aimed to identify predictive factors for percutaneous nephrolithotomy(PCNL)bleeding risks.With better risk stratification,bleeding in high-risk patient can be anticipated and facilitates early identification.Methods:A prospective observational study of PCNL performed at our institution was done.All adults with radio-opaque renal stones planned for PCNL were included except those with coagulopathy,planned for additional procedures.Factors including gender,co-morbidities,body mass index,stone burden,puncture site,tract dilatation size,operative position,surgeon's seniority,and operative duration were studied using stepwise multivariate regression analysis to identify the predictive factors associated with higher estimated hemoglobin(Hb)deficiency.Results:Overall,4.86%patients(n=7)received packed cells transfusion.The mean estimated Hb deficiency was 1.3(range 0-6.5)g/dL and the median was 1.0 g/dL.Stepwise multivariate regression analysis revealed that absence of hypertension(p=0.024),puncture site(p=0.027),and operative duration(p=0.023)were significantly associated with higher estimated Hb deficiency.However,the effect sizes are rather small with partial eta-squared of 0.037,0.066,and 0.038,respectively.Observed power obtained was 0.621,0.722,and 0.625,respectively.Other factors studied did not correlate with Hb difference.Conclusion:Hypertension,puncture site,and operative duration have significant impact on estimated Hb deficiency during PCNL.However,the effect size is rather small despite adequate study power obtained.Nonetheless,operative position(supine or prone),puncture number,or tract dilatation size did not correlate with Hb difference.The mainstay of reducing bleeding in PCNL is still meticulous operative technique.Our study findings also suggest that PCNL can be safely done by urology trainees under supervision in suitably selected patient,without increasing risk of bleeding.

Clinical efficacy and safety of flexible ureteroscopy and percutaneous nephrolithotomy for large kidney stones:A retrospective comparative study

BACKGROUND Renal stones ranging 20–40 mm are very common in China.Although no largesample clinical studies have confirmed the clinical efficacy and safety of this method,there is also a lack of comparative data with traditional treatment.AIM To investigate the clinical efficacy of flexible ureteroscopy(FURS)and percutaneous nephrolithotomy(PCNL)by postoperative stone clearance and changes in soluble vascular cell adhesion molecule 1(sVCAM-1)and kidney injury molecule 1(KIM-1)levels in patients with large kidney stones(>2 cm in diameter).METHODS This single-center observational study was performed at a Chinese hospital between January 1,2021,and October 30,2023.All 250 enrolled patients were diagnosed with large kidney stones(>2 cm)and divided into a FURS group(n=145)and a PCNL group(n=105)by the surgical method.The FURS group was treated with flexible ureteroscopy and the PCNL group was treated with percutaneous nephrolithotomy.The operation time,time to palinesthesia,intraoperative blood loss,drop in hemoglobin,length of hospital stay,stone clearance rate,and complications were recorded in the two groups.Preoperative and postoperative serum sVCAM-1 levels,erythrocyte sedimentation rate(ESR),urine KIM-1 levels,preoperative and postoperative pain visual analog scale(VAS)and Wisconsin Stone Quality of Life Questionnaire(WISQOL)scores were also documented.RESULTS All 250 eligible patients completed the follow-up.There were no significant differences in baseline characteristics between the two groups(P>0.05).The operation time in the FURS group was significantly greater than that in the PCNL group.The time to ambulation,intraoperative blood loss,decrease in hemoglobin,and length of hospital stay were significantly lower in the FURS group than in the PCNL group.The FURS group also had a significantly higher stone clearance rate and a lower incidence of postoperative complications.There was no significant difference in antibiotic use between the groups.Postoperative serum sVCAM-1 levels,urine KIM-1 levels,and VAS scores were lower in the FURS group than in the PCNL group,but postoperative ESR and WISQOL scores were greater in the FURS group than in the PCNL group.CONCLUSION FURS demonstrated superior clinical efficacy in treating large kidney stones(>2 cm in diameter)compared PCNL.It not only improved the postoperative stone clearance rate and reduced complications and recovery time but also positively affected serum SCM-1,ESR,and urine KIM-1 levels,subsequent improvement of patient quality of life.

Clinical Application Study of Super-Mini Percutaneous Nephrolithotomy in the Treatment of Kidney Stones

Objective:To observe the clinical efficacy and complication rates of different stone fragmentation techniques in the treatment of kidney stones.Methods:This study selected 100 patients with urinary stones treated at the Third Division General Hospital from 2021 to November 2023 as subjects.The control group(n=50)received conventional percutaneous nephrolithotomy(PCNL)for stone fragmentation,while the research group(n=50)received super-mini percutaneous nephrolithotomy(SMP)treatment.Surgical parameters,stone clearance rates,recurrence rates,and complication rates were compared between the two groups.Results:After treatment,the surgical parameters in the research group were significantly better than those in the control group.The research group had a higher stone clearance rate and lower rates of stone recurrence and complications(P<0.05).Conclusion:Compared with conventional PCNL,SMP shows better clinical outcomes for patients with kidney stones.It improves surgical parameters,increases stone clearance rates,and reduces both stone recurrence and complication rates,making it a valuable technique for clinical reference.

Miniaturization in percutaneous nephrolithotomy:What is new?

Objective:To summarize recent advancements in mini-percutaneous nephrolithotomy(mini-PCNL)in surgical technique,stone removal strategy,lithotripsy,and surgical model from the current literature.Methods:We conducted a narrative review of relevant English-language articles up to October 2022 using the PubMed and Web of Science databases.The following keywords were used in the search:“percutaneous nephrolithotomy”,“minimally invasive percutaneous nephrolithotomy”,“mini-PCNL”,“mini-perc”,“mPCNL”,and“miniaturization”.Results:A series of new progress has been made in many aspects of mini-PCNL,such as further reduction of tract sizedneedle perc and further improvement of robotic-assisted PCNLdartificial intelligence-powered robotic devices.Conclusion:Many studies and trials have been conducted to reduce morbidity and increase the safety and effectiveness of mini-PCNL.It is crucial to realize that miniaturization of PCNL requires not only a smaller percutaneous tract size,but also an adjustment strategically in renal access,stone removal,lithotripsy,and surgical model in general.More large-scale prospective research needs to be carried out to further validate and optimize the safety and effectiveness of mini-PCNL.

Mini versus ultra-mini percutaneous nephrolithotomy in a paediatric population

Objective:To evaluate whether there would be a difference in outcome when the smaller ultra-mini 12 Fr sheath was used instead of the mini 16 Fr sheath for percutaneous nephrolithotomy(PCNL)in paediatric patients for stones less than 25 mm.Methods:This was a prospective cohort study of patients who underwent PCNL in our hospital in a 2-year period from July 2016 to June 2018 by a single surgeon.PCNL was performed in a prone position and tract was dilated to the respective size using single step dilatation.Laser was used to fragment the stone.Stone-free outcome was defined as absence of stone fragment at 3 months on kidney,ureter,and bladder X-ray.Results:There were 40 patients in each group.Mean stone size was comparable between the two groups(14.5 mm vs.15.0 mm).The procedure was completed faster in the 16 Fr group compared to 12 Fr group(24.5 min vs.34.6 min).Stone clearance was highly successful in both groups(97.5%vs.95.0%).There was no difference in complications between the two groups.The decrease in hemoglobin was minimal in both groups(0.2 g/dL vs.0.3 g/dL).Conclusion:We found that the success rates were similar in both mini PCNL and the smaller ultra-mini PCNL groups.No significant difference in bleeding was noted in our pilot study,however,operative time was longer in the ultra-mini group as compared to the mini sheath group.

Stone-scoring systems for predicting complications in percutaneous nephrolithotomy:A systematic review of the literature

Objective:Percutaneous nephrolithotomy is a treatment of choice for larger stones of the upper urinary tract.Currently,several nephrolithometric nomograms for prediction of post-operative surgical outcomes have been proposed,although uncertainties still exist regarding their roles in the estimation of complications.Methods:We conducted a systematic review on PubMed and Web of Sciences databases including English studies with at least 100 cases and published between January 2010 and December 2021.We identified original articles evaluating correlations between the Guy’s stone score,the stone size(S),tract length(T),obstruction(O),number of involved calices(N),and essence or stone density(E)(S.T.O.N.E.),Clinical Research Office of the Endourological Society(CROES),and Seoul National University Renal Stone Complexity(S-ReSC)scores and post-operative complications in adult patients.We also included newly designed nomograms for prediction of specific complications.Results:After an initial search of 549 abstracts,we finally included a total of 18 papers.Of them,11 investigated traditional nephrolithometric nomograms,while seven newly designed nomograms were used to predict specific complications.Overall,7316 patients have been involved.In total,14 out of 18 papers are derived from retrospective single-center studies.Guy’s stone score obtained correlation with complications in five,S.T.O.N.E.nephrolithometry score in four,while CROES score and S-ReSC score in three and two,respectively.None of the studies investigated minimally invasive percutaneous nephrolithotomy(PCNL)and all cases have been conducted in prone position.Considering newly designed nomograms,none of them is currently externally validated;five of them predict post-operative infections;the remaining two have been designed for thromboembolic events and urinary leakage.Conclusion:This review presents all nomograms currently available in the PCNL field and highlights a certain number of concerns.Published data have appeared contradictory;more recent tools for prediction of post-operative complications are frequently based on small retrospective cohorts and lack external validations.Heterogeneity among studies has also been noticed.More rigorous validations are advisable in the future,involving larger prospective patients’series and with the comparison of different tools.

Reliability of nephrolithometric nomograms in patients treated with minimally invasive percutaneous nephrolithotomy: A precision study

Objectives:The study aimed to evaluate quality of nephrolithometric nomograms to predict stone-free rates(SFRs)and complication rates(CRs)in case of minimally invasive percutaneous nephrolithotomy(PNL).In the last decade,nomograms have been introduced to estimate the SFRs and CRs of PNL.However,no data are available regarding their reliability in case of utilization of miniaturized devices.Herein we present a prospective multicentric study to evaluate reliability of Guy’s stone score(GSS),the stone size,tract length,obstruction,number of involved calyces,and essence of stone(S.T.O.N.E.)nephrolithometry score and Clinical Research Office of the Endourological Society(CROES)score in patients treated with minimally invasive PNL.Methods:We evaluated SFRs and CRs of 222 adult patients treated with miniaturized PNL.Patients were considered stone-free if no residual fragments of any size at post-operative unenhanced computed tomography scan.Patients demographics,SFRs,and CRs were reported and analyzed.Performances of nomograms were evaluated with the area under the curve(AUC).Results:We included 222 patients,the AUCs of GSS,CROES score,and S.T.O.N.E.nephrolithometry score were 0.69(95%confidence interval[CI]0.61-0.78),0.64(95%CI 0.56-0.73),and 0.62(95%CI 0.52-0.71),respectively.Regarding SFRs,at multivariate binomial logistic regression,only the GSS had significance with an odds ratio of 0.53(95%CI 0.31e0.95,p=0.04).We did not find significant correlation with complications,with only a trend for GSS.Conclusion:This is the first study evaluating nomograms in miniaturized PNL.They still show good reliability;however,our data showed lower performances compared to standard PNL.We emphasize the need of further studies to confirm this trend.A dedicated nomogram for minimally invasive PNL may be necessary.

A pilot clinical study of developing an External Assist Targeting Device for rapid and precise renal calyx access during percutaneous nephrolithotomy

Objective:To design a device to increase the accuracy of the targeting process and reduce the radiation exposure to both the patients and the medical staff.Methods:We analyzed the inherent problem and designed the External Assist Targeting Device(EATD)to assist in the alignment of needle targeting on the desired renal calyx under fluoroscopic guidance.The EATD was designed to allow rapid and precise access to calyces at all angles,with a simple two-step puncture protocol developed for puncturing a target renal calyx.We then tested the device in a pilot human trial with four patients.Results:In experiments with phantom models,the time for successful targeting was reduced by 31%using the device.The mean fluoroscopic time was reduced by 40%.In initial human trial,the puncture time was shortened by 66%and the radiation dose was decreased by 65%compared to free-hand technique.No complication was observed during the trial.Conclusion:The EATD was found to be cost effective,portable,simple to set up,and safe to operate for assisting in the percutaneous nephrolithotomy procedures.Our preliminary tests showed high degree of accuracy in gaining precise access to a targeted renal calyx with much shorter time and lesser radiation dose.The EATD also has the potential to be used to access other organs with precision under fluoroscopic guidance.

Miniaturised percutaneous nephrolithotomy:Its role in the treatment of urolithiasis and our experience

Miniaturized percutaneous nephrolithotomy(PCNL)procedures have gained increased popularity in recent years.They aim to reduce percutaneous tract size in order to lower complication rates,while maintaining high stone-free rates.Recently,miniaturized PCNL techniques have further expanded,and can currently be classified into mini-PCNL,minimally invasive PCNL(MIP),Chinese mini-PCNL(MPCNL),ultra-mini-PCNL(UMP),micro-PCNL,mini-micro-PCNL,and super-mini-PCNL(SMP).However,despite its minimally-invasive nature,its potential superiority in terms of safety and efficacy when compared to conventional PCNL is still under debate.The aim of this review is to summarise different available modalities of miniaturized PCNL,details of instruments involved,and their corresponding safety and efficacy.In particular,this article highlights the role of the SMP and our experience with this novel technique in management of urolithiasis.Overall,miniaturized PCNL techniques appear to be safe and effective alternatives to conventional PCNL for both adult and pediatric patients.Well-designed,randomized studies are required to further investigate and identify specific roles of miniaturized PCNL techniques before considering them as standard rather than alternative procedures to conventional PCNL.

Clinical study on the minimally invasive percutaneous nephrolithotomy treatment of upper urinary calculi

BACKGROUND Upper urinary tract stones are very common in my country,with an incidence of 1%to 5%in the North and an even higher incidence of 5%to 10%in the south.The incidence rate in the south is higher than that in the north,mainly due to the water quality,climate and eating habits of the region.From the perspective of sex,incidence is more likely in males than females.In the high-incidence population,young adults are most prone to stones.Men in the age range of 25 to 40 years are more likely to have stones.AIM To observe the therapeutic effect of minimally invasive percutaneous nephrolithotomy(mPCNL)on upper urinary tract stones and its influence on the renal function of patients.METHODS Patients with upper urinary tract stones who were treated in our hospital from February 2017 to March 2018 were selected as research subjects and were divided into the PCNL group and the mPCNL group according to the random number table method.The general conditions of the two groups of patients were observed during the perioperative period,and the differences in stone clearance,pain,renal function indicators and complication rates were compared between the two groups to determine which were statistically significant(P<0.05).RESULTS The operation time of the mPCNL group was longer than that of the PCNL group(t=-34.392,P<0.001),and the intraoperative blood loss of the mPCNL group was more than that of the PCNL group(t=34.090,P<0.001).There was no difference in renal function indices between the two groups of patients before treatment,and there was no difference in the levels of serum creatinine,β2 microglobulin or retinol binding protein in the mPCNL group after treatment.The visual analog scale score of patients in the mPCNL group was lower than that of the PCNL group(t=12.191,P<0.001),and there was no significant difference in the stone clearance rate between the two groups(χ2 value=1.013,P=0.314).There was no significant difference in the incidence of urine extravasation,dyspnea and peripheral organ damage between the two groups(χ2 value=1.053,P=0.305).At 1 mo after treatment and 3 mo after treatment,the quality of life of the mPCNL group was lower than that of the PCNL group,and the Qmax level of the mPCNL group was higher than that of the PCNL group.CONCLUSION mPCNL has a good therapeutic effect on upper urinary tract stones,with a high stone clearance rate without causing kidney damage or increasing the incidence of complications,and thus has good application value.

Risk factors for fever and sepsis after percutaneous nephrolithotomy

Objective:Percutaneous nephrolithotomy(PCNL)is commonly used in the management of large renal stones.Postoperative infections are one of the most common complications of this procedure.The present study is to determine and assess the factors that may increase the risk to develop fever and urinary sepsis after PCNL.Methods:A total of 60 patients(38 males and 22 females)with a mean age of 40.25 years enrolled in this study in Sulaimania Teaching Hospital.Patients had renal stone disease need operation with different socioeconomic status,body mass index and different type and size of stones were included in this study.Patients with preoperative positive urine culture and sensitivity were excluded.Preoperative investigations done for all patients.All Patients received prophylactic antibiotic gentamicin intravenously at the induction of anaesthesia.Renal pelvis urine sample were taken from all patients after puncturing the pelvicalyceal system and send for culture and sensitivity.Patients were monitored closely in the postoperative period for the development of fever and sepsis.Results:Mean duration of the operations was 77.08 min ranged 40e120 min.All patients had postoperative nephrostomy tube.Seventeen(28.33%)patients developed post PCNL fever and the statistically significant factors for post PCNL fever were diabetes mellitus(DM)(p Z 0.001),stone burden(p Z 0.001),number of the stones(p<0.001),degree of hydronephrosis(p Z 0.001),duration of the operation(p<0.001),residual stones(p Z 0.001)and number of tracts(p Z 0.038).Three(5.00%)patients developed post PCNL sepsis,and the statistically significant risk factors for post PCNL sepsis were duration of the operation(p Z 0.013)and intraoperative blood loss,postoperative drop in haemoglobin(HB)level(p Z 0.046).Conclusion:DM,staghorn stones,degree of hydronephrosis,duration of the operation and number of tracts are risk factors for post PCNL fever,while number of stones,intraoperative blood loss,duration of the operation and residual stones are risk factors for post PCNL sepsis.

Percutaneous nephrolithotomy for staghorn calculi: Troubleshooting and managing complications

Staghorn calculi comprise a unique subset of complex kidney stone disease. Percutaneousnephrolithotomy (PCNL) is the gold standard treatment for staghorn stones. Despitecontinuous refinements to the technique and instrumentation of PCNL, these stones remaina troublesome challenge for endourologists and are associated with a higher rate of perioperativecomplications than that for non-staghorn stones. Common and notable intraoperativecomplications include bleeding, renal collecting system injury, injury of visceral organs, pulmonarycomplications, thromboembolic complications, extrarenal stone migration, andmisplacement of the nephrostomy tube. Postoperative complications include infection and urosepsis,bleeding, persistent nephrocutaneous urine leakage, infundibular stenosis, and death.In this review, we report recommendations regarding troubleshooting measures that can beused to identify and characterize these complications. Additionally, we include informationregarding management strategies for complications associated with PCNL for staghorn calculi.

Contemporary role of multi-tract percutaneous nephrolithotomy in the treatment of complex renal calculi

Complex renal calculi remain to be a challenge for the treating urologist due to sheer bulk and the technicalities involved.Percutaneous nephrolithotomy(PCNL)remains the treatment modality of choice in dealing with these large and complex stones.The limiting factor in their treatment continues to be the need for using additional tracts or the use of flexible nephroscopy for complete stone clearance.This systematic review focuses on the need for multi-tract PCNL for complex renal calculi.The literature review was performed using PubMed database using the keywords“multiple tract PCNL”or“multiperc”.We identified original articles published on the usage of multiple tracts for stone clearance in renal calculi between January 2000 to October 2018,and the search was restricted to available literature in English language only.Ten studies with n>20 were included for the final analysis.We analyzed the technical efficacy with respect to the number of tracts and stages that were required for stone clearance,outcomes and complications,especially,procedural bleeding and post-procedure infective complications of multiple-tract PCNL for large burden renal stones.Multiperc is found to be safe,feasible and effective for the management of large burden complex renal calculi with respect to stone clearance and morbidity associated with the procedure.It is cost effective and complete stone clearance as a single procedure is higher in comparison to flexible ureteroscopy and shockwave lithotripsy.

Current insights on haemorrhagic complications in percutaneous nephrolithotomy

Objective:Percutaneous nephrolithotomy(PCNL)is the standard procedure for the management of large and complex renal stones.Blood loss during PCNL may occur during puncture,tract dilatation,and stone fragmentation.Therefore,despite recent advances in PCNL,haemorrhagic complication still occurs.This study aims to enlighten on various aspects of haemorrhagic complication in PCNL,mainly focusing on risk factors and management of this dreadful complication.Methods:Literature search for the study was carried out using advanced search engines like PubMed,Cochrane,and Google Scholar,combining keyword“percutaneous lithotomy”with other keywords like“bleeding”,“haemorrhage”,“complications”,“stone scoring systems”,“mini-PCNL vs.standard”,“dilatation techniques”,“supine vs.prone”,“USG-guided”,“endoscopic combined intra-renal surgery”,“papillary vs.non-papillary puncture”,“bilateral”,and“angioembolization”.The articles published between January 1995 and September 2020 were included for the review.Results:A total of 3670 articles published from January 1995 to September 2020 were screened for the review.Although not consistent,multiple studies have described various preoperative and intraoperative risk factors related to significant bleeding in PCNL.Identification of these risk factors help urologists to anticipate and promptly manage haemorrhagic complications associated with the procedure.A conservative approach suffices to control bleeding in most cases;nevertheless,bleeding can be life-threatening and few still need surgical intervention in the form of angiographic embolisation or open surgical exploration.Conclusion:As hemorrhagic complication in PCNL is associated with considerable morbidity and mortality,prudent intraoperative decision and postoperative care are necessary for its timely prevention,detection,and management.

Retrograde intrarenal surgery vs miniaturized percutaneous nephrolithotomy to treat lower pole renal stones 1.5-2.5 cm in diameter

AIM To compare the outcomes of retrograde intrarenal surgery(RIRS) and miniaturized percutaneous nephrolithotomy(mini-PCNL) in treating lower pole(LP) renal stones with a diameter of 1.5-2.5 cm.METHODS A total of 216 patients who underwent mini-PCNL(n = 103) or RIRS n = 113) for LP stones with a diameter of 1.5-2.5 cm were enrolled between December 2015 and April 2017 at the Urology Department of Ningbo Urology and Nephrology Hospital.RESULTS Significant differences were found in the hospital stay(9.39 ± 4.01 vs 14.08 ± 5.26, P < 0.0001) and hospitalization costs(2624.5 ± 513.36 vs 3255.2 ± 976.5, P < 0.0001) between the RIRS and mini-PCNL groups. The mean operation time was not significantly different between the RIRS group(56.48 ± 24.77) and the mini-PCNL group(60.04 ± 30.38, P = 0.345). The stone-free rates at the first postoperative day(RIRS vs mini-PCNL: 90.2% vs 93.2%, P = 0.822) and the second month postoperatively(RIRS vs mini-PCNL: 93.8% vs 95.1%, P = 0.986) were not significantly different.CONCLUSION RIRS and mini-PCNL are both safe and effective methods for treating LP stones with a diameter of 1.5-2.5 cm. RIRS can be considered as an alternative to PCNL for the treatment for LP stones of 1.5-2.5 cm.

Ultrasonography-guided Percutaneous Nephrolithotomy with Chinese One-shot Tract Dilation Technique Based on Stimulated Diuresis:A Report of 67 Cases

The safety and effectiveness of a novel Chinese one-shot dilation technique based on stimulated diuresis for percutaneous nephrolithotomy（PCNL） were investigated.After the feasibility of the Chinese one-shot dilation based on stimulated diuresis was verified by an animal study,this technique was applied in the clinical practice.A total of 67 patients in our department underwent the modified PCNL from July 2014 to June 2015.After the renal infundibulum was distended by stimulated diuresis,the kidney was punctured under the ultrasonographic guidance via the fornix of the target calyx.The working channel was dilated using a special designed pencil-shaped fascial dilator.The successful access rate,nephrostomy tract creation time,pre-and postoperative hemoglobin values and serum creatinine concentrations,stone-free rate and complications were recorded and analyzed.The renal infundibulum was successfully distended in all of the patients by the diuresis treatment.Under the ultrasonographic guidance,the successful access rate was 100% and the mean tract creation time was 2.0 min（range：1.5–5.0 min）.The stone-free rate right after surgery was 91.0%.Although the postoperative hemoglobin was significantly reduced（P〈0.01）,transfusion was not clinically necessary.There was no significant difference in serum creatinine concentrations before and after operation（P〉0.05）.No severe complication occurred during or after the PCNL.It was suggested that this Chinese one-shot dilation technique based on stimulated diuresis is an efficient and safe innovation for PCNL,and is even helpful for those patients with non-dilated pelvicaliceal systems.

Present indications and techniques of percutaneous nephrolithotomy:What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy(PCNL)procedure in terms of indications and evolving techniques,and to identify the advantages and disadvantages of each modality.The data for this review were collected after a thorough PubMed search in core clinical journals in English language.The key words included“PCNL”and“PNL”in combination with“indications”,“techniques”,“review”and“miniaturized PCNL”.Publications relevant to the subject were retrieved and critically reviewed.Current European and American Urology Association Nephrolithiasis Guidelines were included as well.The indications for standard PCNL have been changed through the past decade.Despite evolution of the procedure,innovations and the development of new technical approaches,the indications for miniaturized PCNL have not been standardized yet.There is a need for well-constructed randomized trials to explore the indications,complications and results for each evolving approach.A continuous reduction of tract size is not the only revolution of the last years.There is constant ongoing interest in developing new efficient miniature instruments,intracorporeal lithotripters and sophisticated tract creation methods.We can summarize that,PCNL represents a valuable well-known tool in the field of endourology.We should be open minded to future changes in surgical approaches and technological improvements.