Feasibility of contrast-enhanced ultrasound and flank position during percutaneous nephrolithotomy in patients with no apparent hydronephrosis: a randomized controlled trial

Purpose

To investigate the puncture accuracy and feasibility of contrast-enhanced ultrasound (CEUS) guided percutaneous nephrolithotomy (PCNL) in flank position for patients with no apparent hydronephrosis.

Methods

Between May 2018 and June 2020, 72 kidney stone patients with no or mild hydronephrosis were randomized into two groups: a CEUS-guided PCNL group and a conventional ultrasound (US)-guided group. Patients’ demographics and perioperative outcomes were compared, including the success rate of puncture via calyceal fornix, the success rate of a single-needle puncture, puncture time, operative time, postoperative hemoglobin loss, stone-free rate, incidence of complications and postoperative stay.

Results

The success rate of puncture via calyceal fornix for CEUS-guided group was significantly higher than that for conventional US-guided group (86.1 vs. 47.2%, p = 0.002). Patients performed with CEUS-guided PCNL required shorter renal puncture time than those guided with conventional US (36.5 s vs. 61.0 s, p < 0.001). The median postoperative hemoglobin loss in the CEUS-guided group was significantly lower than that in conventional US-guided group (2.5 vs. 14.5 g/L, p < 0.01). There was no statistically significant difference in the success rate of a single-needle puncture, operative time, stone-free rate, incidence of complications and postoperative stay between the two groups.

Conclusion

CEUS guidance facilitates identification of the renal calyx fornix, and benefits more precise renal puncture and less hemoglobin loss in PCNL. CEUS-guided PCNL in flank position is a feasible approach to the treatment of kidney stone patients with no apparent hydronephrosis.

Trial registration number: ChiCTR1800015417.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-03933-4.

RISK OF OCCURRENCE AND WAYS TO IMPROVE THE TREATMENT OF UROLITHIASIS IN PATIENTS WITH A SINGLE KIDNEY

OBJECTIVE

The aim: To summarize the state of the problem of urolithiasis in patients with a single kidney and consider current views on improving its treatment based on the analysis of world literature.

PATIENTS AND METHODS

Materials and methods: The study conducted a thorough analysis of modern scientific literature sources in the international scientometric database, which highlighted the development of urolithiasis in patients with a single kidney and the peculiarities of its treatment. The main ways to improve treatment are identified. A critical assessment of the achievements and shortcomings of various surgical treatments. The authors' own developments are presented in the article.

CONCLUSION

Conclusions: The topographic position of the kidney in the retroperitoneal space affects not only the occurrence of pathological processes in the kidney, but also the surgical strategy in the treatment of nephrolithiasis. Percutaneous nephrolithotomy is the main treatment for large (> 2 cm) or complex kidney stones. Patients with a single kidney are more prone to bleeding with PCNL treatment than patients with bilateral kidneys because they have an increased thickness of the renal parenchyma as a result of compensatory hypertrophy. RIRS is a reliable choice for patients with a single kidney who is contraindicated in PCNL.

Comparison of the outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for the treatment of kidney stones: a matched-pair analysis

OBJECTIVE

Mini-percutaneous nephrolithotomy is a recent advancement in the field of kidney stone treatment; however, its role has not been completely established. We aimed to compare the outcomes of initial Mini-percutaneous nephrolithotomy and flexible ureteroscopy.

METHODS

A retrospective review of consecutive mini-percutaneous procedures was performed. Inclusion criteria were as follows: all percutaneous nephrolithotomy procedures performed with an access sheath up to 24Fr, kidney stone burdens up to 1550 mm3; and the presence of postoperative computed tomography (for control). The data collected for Mini-percutaneous nephrolithotomy procedures were paired 1:2 with patients treated with flexible ureteroscopy for stones between 100 and 1550 mm3, and with postoperative computed tomography for control. A 14Fr Mini-percutaneous nephrolithotomy set was used. The stone-free rate was defined as the absence of fragments on the control computed tomography, whereas success was limited to 2-mm residual fragments. Statistical analysis was performed using SPSS version 19.

RESULTS

A total of 63 patients met the inclusion criteria (42 with flexible ureteroscopy and 21 with mini-percutaneous nephrolithotomy). Demographic data were comparable. The stone-free rate and success were similar between the groups (76.2 vs. 66.7%, p=0.42 and 90.5 vs. 85.7%, p=0.57). The complication rate was also similar (26.1 vs. 9.6%, p=0.188), but Mini-percutaneous nephrolithotomy had longer hospitalization and fluoroscopy time (p=0.001 in both).

CONCLUSIONS

Our initial study of Mini-percutaneous nephrolithotomy showed that it is a promising procedure, with outcomes similar to flexible ureteroscopy, but with higher inpatient numbers and fluoroscopy times. A larger study population size and better equipment may improve the outcomes of mini-percutaneous nephrolithotomy.

The use of supine PNL technique for a tubeless procedure and shorter hospital stay: A comparison of supine and prone PNL procedures in 361 cases

OBJECTIVE

To compare the efficacy and safety of prone and supine percutaneous nephrolithotomy (P/SPNL) with special emphasis on tubeless (T) and totally tubeless (TT) surgery.

MATERIAL AND METHODS

This retrospective, single-surgeon, consecutive series comparison study involved 361 consecutive patients who under went PNL operations in either the prone or Galdakao-modified Valdivia supine positions between September 2016 and March 2020. Indication for surgery was a stone diameter greater than 2 cm. The two groups were compared in terms of preoperative demographics, stone parameters, and perioperative data.

RESULTS

The groups were similar in terms of preoperative demographics, while the blood transfusion rate was insignificantly higher in PPNL (7% vs 3.3%, p=0.165). Mean operative time (58.0±20.6 vs 54.1±15.9 min., respectively, p=0.165), fluoroscopy time (p=0.895), and Clavien complication rates (p=0.87) were similar. SPNL exhibited a significantly (p<0.001) higher rate of T operations (23, 37.7%) than PPNL (46, 15.3%). TT cases were also higher with SPNL (14% vs 29.5%,p=0.003). Urine leakage (p=0.085) and post-operative JJ stent placement (p=0.180) rates were statistically similar between the two groups. Length of hospital stay was approximately one day shorter for T cases in both groups (PPNL: 1.37±0.80 vs 2.26±1.28 days, p=0.001; SPNL: 1.65±0.83 vs 2.76±2.27 days, p=0.028). Stone free rates were 91.3% and 88.5% for PPNL and SPNL, respectively (p=0.488).

CONCLUSION

SPNL has proved to be as safe and effective as its prone counter part, with similar stone-free and complication rates. T and TT-PNL seem more viable with SPNL, which will increase patient comfort and allow shorter hospitalization times.

[The use of ultrasound imaging in minimally invasive percutaneous nephrolithotomy. Can we completely abandon fluoroscopy?]

AIM

To determine the possibility of performing minimally invasive percutaneous nephrolithotomy (PCNL) under ultrasound guidance with the use of X-ray during the access tract formation.

MATERIALS AND METHODS

The results of 102 mini-PNL procedures, performed by a single surgeon during the period 2018-2019, were analyzed retrospectively. In the beginning, ureteral catheter Ch5 was put into an ipsilateral ureter. Further, a puncture of the collecting system was performed with an advancement of the guidewire. At the next stage, a dilation of tract was done using X-ray guidance for the safe formation of the working channel, followed by holmium lithotripsy. At the end a nephrostomy or JJ-stent was left.

RESULTS

The mean age of the patients was 53.13+/-12.9, while average BMI was 29.3+/-6.5. In total, there were 44.1% of women. The average stone size was 20.7+/-10.9 mm; 45.1% of stones were left-sided. Staghorn stones accounted for 15.7% of cases and hydronephrosis was found in 18.6% of patients. The time for creating renal access, dilation of the nephrostomy tract, total operative time and fluoroscopy time were: 19.6+/-13.1, 7.7+/-4.2, 107.7+/-49.9, 57.1+/-41.2 minutes, respectively. In the Group I there were 32 (31.4%) patients undergoing to PCNL under X-ray guidance, while in Group II (n=70, 68.6%) combined US+/-X-ray control was used. The patients age (52.2+/-12.6 vs 53.6+/-13.2, p<0.05) and the stone size (20.6+/-8.9 vs 20.7+/-10.4, p=0.30) were comparable in both groups. There were slightly shorter access time and the total operative time in group II compared with group I (20.6+/-12.3 vs 19.2+/-13.5, p=0.27; 108.1+/-43.3 vs 106.9+/-53.2, p=0.25 respectively). In total, hematocrit level decreased by 4.5% and blood transfusions was done in 3 patients. Postoperative complications developed in 9 cases in both groups (according to the Clavien-Dindo classification, all complications were grade I-II). The stone-free rate (SFR) was 87.2%, and a second-stage was required in 2 cases.

DISCUSSION

The use of ultrasound guidance improves visualization of the collecting system and contributes to the creation of an optimal renal access. It significantly reduces the radiation exposure to the patient and the operating team. We were able to puncture the collecting system in all cases. SFR after PCNL under ultrasound guidance was 88.6%, which is comparable to the results of conventional PCNL with X-ray navigation.

CONCLUSION

PCNL can be performed effectively and safely under ultrasound guidance, which reduces the number of renal punctures and lowers the complication rate. However, this technique also has disadvantages, including longer puncture time in morbidly obese patients without hydronephrosis. With growing experience, the number of unsuccessful kidney punctures decreases, as well as operative time. The use of fluoroscopy during dilatation of the nephrostomy tract allows for preventing additional injuries of the collecting system.

Multi-Institutional Prospective Randomized Control Trial of Novel Intracorporeal Lithotripters: ShockPulse-SE vs Trilogy Trial

Introduction: Currently, there are multiple intracorporeal lithotripters available for use in percutaneous nephrolithotomy (PCNL). This study aimed to evaluate the efficiency of two novel lithotripters: Trilogy and ShockPulse-SE. Materials and Methods: This is a prospective multi-institutional randomized trial comparing outcomes of PCNL using two novel lithotripters between February 2019 and June 2020. The study assessed objective measures of stone clearance time, stone clearance rate, device malfunction, stone-free rates, and complications. Device assessment was provided through immediate postoperative survey by primary surgeons. Results: There were 100 standard PCNLs completed using either a Trilogy or ShockPulse-SE lithotrite. Using quantitative Stone Analysis Software to estimate stone volume, the mean stone volume was calculated at 4.18 ± 4.79 and 3.86 ± 3.43 cm3 for the Trilogy and ShockPulse-SE groups, respectively. Stone clearance rates were found to be 1.22 ± 1.67 and 0.77 ± 0.68 cm3/min for Trilogy vs ShockPulse-SE (p = 0.0542). When comparing Trilogy to ShockPulse-SE in a multivariate analysis, total operative room time (104.4 ± 48.2 minutes vs 121.1 ± 59.2 minutes p = 0.126), rates of secondary procedures (17.65% vs 40.81%, p = 0.005), and device malfunctions (1.96% vs 34.69%, p < 0.001) were less, respectively. There was no difference in final stone-free rates between devices. Conclusion: Both the Trilogy and ShockPulse-SE lithotripters are highly efficient at removing large renal stones. In this study, we noted differences between the two devices including fewer device malfunctions when Trilogy device was utilized. Clinical Trial ID number: NCT03959683.

Contemporary considerations in the management and treatment of lower pole stones

The presence of lower pole stones poses a unique challenge due to the anatomical considerations involved in their management and treatment. Considerable research has been performed to determine the optimal strategy when faced with this highly relevant clinical scenario. Standard options for management include observation, shock wave lithotripsy, retrograde intrarenal surgery, or percutaneous nephrolithotomy. Indeed, each approach confers a distinct set of risks and benefits, which must be placed into the context of patient preference and expected outcomes. The current state of practice reflects a combination of lessons learned from managing calculi not only in the lower pole, but also from other locations within the kidney as well.

Automated Needle Targeting with X-ray (ANT-X) - Robot-assisted device for percutaneous nephrolithotomy (PCNL) with its first successful use in human

INTRODUCTION

To make percutaneous access easier in PCNL, we developed Automated Needle Targeting with X-ray (ANT-X).

METHOD

ANT-X uses an image registration software with a closed loop feedback system to autoalign the puncture needle to the desired calyx using the bullseye technique. We tried percutaneous punctures on a live pig model and compared the results with free-hand technique. We then performed our first PCNL in a human subject with the aid of ANT-X. Our patient was a 48 year-old gentleman with a 1.4cm left lower pole stone.

RESULTS

Initial results for live animal trial showed radiation exposure for robot-assisted arm during puncture was reduced by 26% compared to the free-hand technique (8.2mGy vs 11.2mGy). In the human trial, obtaining percutaneous access was successful at first attempt.

CONCLUSION

ANT-X system can help surgeons feel confident and potentially reduce complications, hence enabling more surgeons to adopt this procedure.

Changes in percutaneous approach to kidney stones in children: A single institute experience over 500 cases

PURPOSE

The aim of this study is to identify the changes in patient age and stone sizes with technological advancement over time.

METHODS

This study was conducted retrospectively with 404 patients (504 renal units) who underwent percutaneous nephrolithotomy (PCNL) between January 1997 and June 2020. Patient characteristics and trends on instrument preferences were investigated.

RESULTS

Median age was 7 (1-18) years. Male to female ratio was 1.48:1 (301/203). Median stone burden was 2 cm² (0.20-25) and median operative time was 90 minutes (20-240). The stone-free rate was 74.6%. Patients were divided into four groups according to the size of the instrument. It was found that the size of sheath used increased significantly with increasing age and stone burden. The micro-PCNL group had the shortest hospitalisation and lowest blood transfusion rate. Chronologically categorised four equal groups were compared to analyse changing patient profiles and trends. Median patient age, stone burden, operation time, sheath size, blood transfusion and complication rates decreased significantly with time. However, the use of tracts smaller than 20F and the number of patients with previous intervention increased significantly.

CONCLUSION

Our study demonstrated that the patient's age and stone size at the time of initial diagnosis decrease over time while miniaturisation techniques increase in paediatric urology.

Evolution of Urology Services in Pakistan

Urology has been separated from its parent generic specialty at different times during the last 150 years in different countries. In Pakistan, from 1947 to 1970s, urology was part of surgery and was done by general surgeons. There were only two urology units from late 1950s to early 1960s. The actual rise of urology started with the introduction of trans-urethral resection of prostate (TURP) in 1980s with the introduction of endourology. Use of cystoscopy and retrograde ureteropyelography was in vogue much before TURP. The second era of modern endourology began with the introduction of percutaneous nephrostomy, ureteroscopy along with ESWL, and percutaneous nephrolithotomy in late 1980s and 1990s. Renal transplantation started in 1979 from living-related donors in public sector hospitals. Now, there are 19 centres in the country performing regular renal transplantions. Urology has undergone a dramatic change during the new millennium. There have been sub-specialties in urology, like paediatric urology, endourology, reconstructive urology, uro-oncology, laparoscopic and robotic urology. At present, there are 11 specialised kidney centres and institutes of urology in the country and 25 recognised urology centres for FCPS. More such centres and replication of the SIUT model is expected in Pakistan. Key Words:  Urology, Endourology, Transplantation, Pakistan.

Comparison of laparoscopic pyelolithotomy and retrograde intrarenal surgery in the management of large renal pelvic stones

BACKGROUND

To compare the clinical outcomes of laparoscopic pyelolithotomy (LP) and retrograde intrarenal surgery (RIRS) in the management of large renal pelvic stones.

PATIENTS AND METHODS

This study included patients who presented with a single renal pelvic stone sized ≥20 mm and who were treated primarily by LP or RIRS. The patients were grouped based on the surgical procedure they underwent. We retrospectively examined and compared the age, the longest axis, and the surface area of the stone, operation time, hospitalization time, complications, and stone-free rates of the two groups.

RESULTS

Of the 156 patients included in the study, 44 had LP, and 112 had RIRS. Patients who received LP (13 males, 31 females) had a median age of 54 (18-79) years, while those who underwent RIRS (46 males, 66 females) had a median age of 54.5 (18-79). Patients who received LP were found to have larger median stone size (30 mm vs 24 mm, P = .003), longer operation time (100 minutes vs 70 minutes, P = .007), lower complication rate (2% vs 8.9%, P = .063), longer median hospital stay (3 days vs 1 day, P < .001) and better stone-free rate at the third month (90.9% vs 67.9%, P < .001).

CONCLUSION

LP is a safe and efficient procedure that could be used as an alternative to RIRS in managing large renal pelvic stones.

A Management of Ureteral Obstruction After Lichtenstein Tension-Free Hernia Repair in a Kidney Transplant Recipient: A Case Report

BACKGROUND

The number of renal transplants has been increasing in recent years. Recent literature data show that abdominal operations performed on patients who undergo renal transplant have higher morbidity and mortality.

CASE PRESENTATION

A 49-year-old man who had received a renal transplant from a living donor 19 years ago underwent Lichtenstein tension-free hernia repair. Anuria was observed after the operation. Renal ultrasound demonstrated massive hydronephrosis and an elevated serum creatinine level (4.6 mg/dL). It was thought that the ureter may have been obstructed because of the operation, and, with the patient under local anesthesia, all sutures and polypropylene mesh were removed. Urine output was still not present, so a percutaneous nephrostomy catheter was inserted to normalize renal function. The patient underwent reoperation under general anesthesia 45 hours after the first operation. It was observed that the ureter was ligated during high ligation. The ureter was released, and no additional intervention was performed. The patient was discharged 6 days later with a return to basal creatinine level and a percutaneous nephrostomy catheter. The patient was hospitalized twice for severe urinary tract infection and urosepsis within 3 months and received appropriate treatment. The patient has had an uneventful postoperative course for 18 months.

DISCUSSION

Inguinal hernia repair is seen as a safe surgical procedure, but the risk of emerging urological complications is higher in patients with renal transplant. Imaging before surgery to identify the anatomy of the kidney and ureter may be useful. Delicate dissection of the extraperitoneal area during the operation will reduce surgical complications.

Technical aspects to maximize the hyperaccuracy three-dimensional (HA3D™) computed tomography reconstruction for kidney stones surgery: a pilot study

The aim of the current prospective pilot study was to describe a hyperaccuracy three-dimensional (HA3D^™) model reconstruction technique, specifically developed to maximize the visualization of the renal collecting system's anatomy, and its relationship with the stones, vessels and renal parenchyma, and to compare the HA3D^™ virtual models with the intraoperative findings. The image acquisition was performed using a CT scanner (Toshiba, Aquilion Prime) and included the unenhanced, arterial, venous and excretory phases. The DICOM format CT images were processed by MEDICS Srl ( www.medics3d.com , Turin, Italy). In total, study included three patients with renal stone scheduled for non-papillary prone percutaneous nephrolithotomy (PCNL). The median age and BMI were 51 (range 49-54) and 25.5 (range 25.0-32.7), respectively. The median stone size was 1170 mm² (range 830-1520) and median stone density was 1130 HU (range 600-1340). In all cases, the quality of the CT images acquired with our protocol was adequate to perform the HA3D^™ reconstruction. Median operative and puncture time were 39.4 (range 35.2-44.0) and 1.9 (range 1.8-2.1) mins, respectively. The success rate for the first attempt of the percutaneous puncture was 100%, and only one PCNL tract was sufficient to complete the surgery. All three patients were stone-free on the third postoperative day. A dedicated imaging acquisition protocol and a tailored 3D model reconstruction process specifically developed for kidney stones treatment allow obtaining HA3D^™ highly relevant models to greatly match intraoperative findings during PCNL with the potential of minimizing bleeding and organ injury complications.

[InsKid Mobile application for the reconstruction of the internal view of the collecting system]

INTRODUCTION

patients with urinary stone disease during consultation often cannot realize their condition and features of upcoming procedure. Creation of 3D printed models is also not always available or too expensive.

AIM

to create a special program that allows for virtual intrarenal visualization of the collecting system and kidney stone on devices based on the Android operating system and evaluate its efficiency in counseling patients before the upcoming percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

a total of 15 patients who were scheduled to PCNL, were included in the study. All of them had two consultations. During the second consultation, the newly developed program was used. Patient data from DICOM (computed tomography) format were converted to stereolithography (STL) format in order to display it in the application. Each patient assessed the quality of the consultation using a questionnaire.

RESULTS

patients understanding of the kidney anatomy improved by 55% (from 34 to 75 points, p=0.0001), and stone localization by 51% (from 37 to 75 points, p=0.0001). The stages of PCNL became clearer by 57% (from 32 points to 75, p=0.0001), and understanding of possible intra- and postoperative complications was improved by 48% (from 38 to 73 points, p=0.0002). Overall patient satisfaction with counseling improved by 53% (from 35 to 74 points, p=0.0001), and the number of patients who desired for better repeated counseling decreased by 89% (from 9 to 1, p=0.006).

CONCLUSION

The InsKid app is an affordable and easy-to-use program, which doesnt require significant costs and allows patients to understand their disease and upcoming procedure.

Comparison of retrograde intrarenal surgery and percutaneous nephrolithotomy in multiple calyceal stones: A match pair analysis of 190 cases

OBJECTIVES

The current nephrolithia-sis guidelines have no recommendation about multiple calyceal stones treatment. We aimed to compare the results of two effective methods of RIRS and PNL operations in the treatment of multicalyx stones.

METHODS

Data of patients who underwent RIRS or PNL for multicalyx stones between September 2014 and May 2019 in our clinic were evaluated retrospectively. In both groups, stone-free and complication rates, hospital stay, scopy times, and operation times were examined. In RIRS group, the number of sessions and total stone-free rates at the end of each session were evaluated separately.

RESULTS

A total of 162 patients in the RIRS group, and 103 patients in the PNL group were evaluated. After the match pair 1:1, data of 95 patients were selected in each group. Stone burden, number, density, ASA scores, BMI were similar in both groups. At the end of the first session RIRS, 59 (62.1%) patients became stone-free, while in the PNL group 73 (76.8%) patients (p: 0.027). The statistical analysis showed that the stone-free rates obtained in the second sessions in the RIRS group were similar to those of the PNL group. After a total of 124 sessions of RIRS, a stone-free rate of 81.1% was achieved by 1.3 sessions on average.

CONCLUSION

At least two session of RIRS is as effective as PNL on multiple calyceal stones. Stage RIRS can be an alternative to PNL at multicalyceal renal stones.

[Specific immunization for the prevention of recurrent nephrolithiasis after percutaneous nephrolithotomy]

AIM

To study the effect of prophylactic immunization with combined Staphylococcus-Proteus-Pseudomonas vaccine in combination with the probiotic Bacillus subtilis on the development of recurrent nephrolithiasis in patients after percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

A total of 76 patients with a high infectious risk of stone formation in the early postoperative period after PCNL were included in the study. All patients received antibiotic therapy in accordance with the current guidelines as indicated. The patients were divided into 3 groups. In the comparison group (n=30), patients continued to receive antibiotics on the outpatient basis. In the group A (n=20), in addition to antibiotics, two-stage immunization with Staphylococcus-Proteus-Pseudomonas vaccine was performed. In the group B (n=26), additionally, patients received probiotic preparation "Bactisporin dry", which is a lyophilized spore-forming bacteria Bacillus subtilis strain 3N. All participants had urine culture and stone analysis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A study of specific antibodies level and factors of cellular and humoral immunity was carried out at specific time points. The duration of follow-up was 36 months.

RESULTS

The study revealed a difference in the pathogens isolated from urine and infection stones in the same patient. This convincingly suggests that pathogens form biofilms in the stones and are not detected during routine urine culture. The main pathogens isolated from the stones were Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus epidermidis and Klebsiella pneumonia. Microbial associations were found in 25.7% of cases. The Staphylococcus-Proteus-Pseudomonas vaccine demonstrated good immunogenicity, its antigenic components provided protective properties against autologous and opportunistic bacteria. In addition to the ability to induce a specific response to antigens, the vaccine stimulated the phagocytic activity of neutrophils. Immunization with the combined Staphylococcus-Proteus-Pseudomonas vaccine in combination with probiotic results in uncomplicated postoperative course in 84% of patients. Hospital-acquired infectious and inflammatory complications were seen in 16.2% of cases. The recurrence of stone formation in this group of patients within 36 months was 8.2%. In patients receiving only combined Staphylococcus-Proteus-Pseudomonas vaccine after PCNL, the postoperative period was uneventful in 65% of cases. The rate of upper urinary tract infection was 35%, while the inflammatory process was accompanied by mild clinical manifestations and quickly resolved. Recurrence of stone formation during the follow-up was seen in 18% of patients. In the control group, the proportion of uncomplicated cases in patients with nephrostomy tube was 40%, the development of pyelonephritis was noted in 60% of cases, and recurrent stones within 36 months were diagnosed in 46.7% of cases.

CONCLUSION

Our results emphasize that the role of an infectious factor in the development of recurrent nephrolithiasis after PCNL is often underestimated. The use of a specific vaccination and the Bacillus subtilis preparation in patients with a high infectious risk of recurrent stone formation allows to achieve a significant reduction in the recurrence rate (more than 5 times) compared to the control group during 36 months of postoperative follow-up.

Nephrostomy tubes placed emergently prior to percutaneous renal stone surgery are practical for obtaining access

OBJECTIVES

Renal access in percutaneous nephrolithotomy (PCNL) may be obtained via a pre-existing nephrostomy tube (NT) tract; however, emergent NTs are not always ideal for subsequent surgery. We sought to determine the rate of NT tract usability and assess factors related to the usability of emergently placed NTs.

METHODS

A retrospective review was performed of UC San Diego subjects undergoing percutaneous renal surgery between January 2016 and October 2018. Demographics and peri-operative variables were collected. The primary outcome was the usability of NT tract for dilation and instrumentation. "Usable" indicated a tract in which PCNL could be completed; "unusable" indicated lack of dilation and the requirement of additional tract(s) for PCNL.

RESULTS

35 PCNL cases had previous emergently placed NT which were indwelling at time of percutaneous surgery. 51% of these NT tracts (18/35) were deemed usable and dilated for PCNL. No significant difference was seen between usable and unusable NT groups for number of dilated tracts during PCNL (p=0.13), or either the location of indwelling NT (p=0.96) or renal stones (p=0.95). In the usable NT tract cohort PCNL access was via the lower pole 56% of the time, where as when previous NT tracts were deemed unusable, a separate upper-pole access was obtained intra-operatively 53% of the time (p<0.01).

CONCLUSIONS

Pre-existing, emergent NTs served a ssufficient PCNL access tracts in over half of recorded cases. Contrary to recently published reports, the utility of pre-existing NTs appears to vary among health systems. Other variables, including the desired location of PCNL appear to directly influence the like lihood of NT tract usability.

Staghorn renal stones: what the urologist needs to know

Patients with staghorn renal stones are challenging cases, requiring careful preoperative evaluation and close follow-up to avoid stone recurrence. In this article we aim to discuss the main topics related to staghorn renal stones with focus on surgical approach. Most of staghorn renal stones are composed of struvite (magnesium ammonium phosphate) and are linked to urinary tract infection by urease-producing pathogens. Preoperative computed tomography scan and careful evaluation of all urine cultures made prior surgery are essential for a well-planning surgical approach and a right antibiotics choice. Gold standard surgical technique is the percutaneous nephrolithotomy (PCNL). In cases of impossible percutaneous renal access, anatrophic nephrolithotomy is an alternative. Shockwave lithotripsy and flexible ureteroscopy are useful tools to treat residual fragments that can be left after treatment of complete staghorn renal stone. PCNL can be performed in supine or prone position according to surgeon's experience. Tranexamic acid can be used to avoid bleeding. To check postoperative stone-free status, computed tomography is the most accurate imaging exam, but ultrasound combined to KUB is an option. Intra-operative high-resolution fluoroscopy and flexible nephroscopy have been described as an alternative for looking at residual fragments and save radiation exposure. The main goals of treatment are stone-free status, infection eradication, and recurrence prevention. Long-term or short-term antibiotic therapy is recommended and regular control imaging exams and urine culture should be done.

Ultrasound or Fluoroscopy for Percutaneous Nephrolithotomy Access, Is There Really a Difference? A Review of Literature

Objective: To compare whether the outcomes of ultrasound-guided access percutaneous nephrolithotomy (USGA-PCNL) are similar to standard fluoroscopy-guided access percutaneous nephrolithotomy (FGA-PCNL). Methods: A review was developed by using the MEDLINE and Scopus databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Studies comparing the USGA-PCNL and the FGA-PCNL were included. Case reports, editorials and letters, unpublished studies, posters, and comments abstracts were excluded. Results: We found 12 published articles that compared USGA-PCNL and FGA-PCNL. These included six randomized controlled trials, three case-control trials, and three meta-analyses. The overall results showed no difference in the success of percutaneous access, bleeding, blood transfusion, operative time, postoperative complications, or hospital stay. Conclusion: The reported data demonstrate that there are no significant differences between the fluoroscopic-guided access PCNL and the ultrasonographic access PCNL. The choice of puncture depends on the surgeon's expertise in a particular technique and the patient and stone characteristics. Both approaches are equally safe and effective in experienced hands. It is important to recall that the use of one technique does not exclude the use of the other, and they can sometimes be complementary to each other.

Comparison of miniaturized percutaneous nephrolithotomy and retrograde intrarenal surgery: Which is more effective for 10-20 mm renal stones in children?

OBJECTIVE

To compare miniaturized percutaneous nephrolithotomy (mini-PNL) and retrograde intrarenal surgery (RIRS) in children with 10-20 mm renal stones. MATERIALS AND METHODS: Between 2015 and 2019, 63 pediatric patients aged under 16 years who under went mini-PNL and RIRS for the treatment of kidney stones sized 10-20 mm were analyzed retrospectively. The mini-PNL group (n=30) was defined as group 1 and the RIRS group (n=33) was defined as group 2. Peri-operative data including stone-free rate, operative time, fluoroscopy time, hospitalization time, number of anesthesia sessions, complication rates, and cost-effectiveness were analyzed.

RESULTS

The mean age was 8.09±5.49 years in group 1 and 5.75±4.56 years in group 2. The stone free rate was not different at the first (80.0% vs. 57.6%) and third month (93.3% vs. 90.9%) follow-up in group 1 and group 2. The mean hospitalization, operative, and fluoroscopy times were statistically significantly longer in group 1. The mean number of anesthesia sessions for patients was 1.20±0.40 in group 1 and 2.15±0.44 in group 2 (p=0.00). Minor complication rates were not different and no major complications were observed in either group. The cost per patient was calculated as 365.97 Euros in group 1 and 698.64 Euros in group 2 (p=0.001). CONCLUSIONS: This study suggested that RIRS was an effective alternative treatment method for 10-20 mm kidney stones in children, with comparable stone-free and complication rates. RIRS has a shorter operative time, fluoroscopy time, hospital stay than mini-PNL, with a similar stone-free rate for 10-20 mm kidney stones in children. However, mini-PNL is cheaper and allowed a lower need for anesthesia sessions.

[Endoscopic combined ultrasound-guided access vs. ultrasound-guided access in endoscopic combined intrarenal surgery]

OBJECTIVE

To compare the outcomes of endoscopic combined ultrasound-guided access (EUGA) with the conventional ultrasound-guided access (UGA) to achieve percutaneous renal access in endoscopic combined intrarenal surgery (ECIRS).

METHODS

A retrospective review of 53 patients undergoing ECIRS to treat upper urinary tract calculi between January 2017 and October 2019 was con-ducted. All of the cases were of complex upper urinary tract stones larger than 2 cm in diameter. The com-plex stone situations, such as multiple renal calyces calculi or staghorn calculi necessitated ECIRS. Under general anesthesia, the patients were placed in the galdakao-modified supine valdivia (GMSV) position, thus allowing both antegrade and retrograde accesss. The patients were divided to UGA and EUGA groups according to the protocol of achieving percutaneous renal access. In 28 cases, endoscopic combined ultrasound-guided accesss were obtained. Puncture and dilation were performed under direct flexible ureteroscopic visualization, while percutaneous renal access of 25 cases were performed with the conventional technique employing ultrasound guidance. Demographic and perioperative information, such as stone burden, presence of hydronephrosis and number of calyces involved was compared. Primary outcomes included total operative time, renal access time, repeat puncture, hemoglobin level, perioperative complications, and stone-free rate.

RESULTS

No major intra-operative complication was recorded in all the 53 ECRIS. No significant difference was observed between the groups in age and gender. There was no significant difference in body mass index[BMI (29.21±3.14) kg/m2 vs.(28.53±2.56) kg/m2], stone burden (37.68±6.89) mm vs. (35.53±6.52) mm, number of calyces involved 2.72±0.68 vs. 2.86±0.71, presence of hydronephrosis (56.0% vs. 46.4%), total operative time (93.0±12.2) min vs. (96.8±14.2) min, hemoglobin level reduction (6.56±2.16) g/L vs. 97.54±2.64) g/L, stone-free rate (92.0% vs. 92.8%), hospital stay (5.52±0.59) d vs. (5.64±0.62) d, perioperative complication rate (8.0% vs. 7.2%). Two patients in EUGA group experienced perioperative complications (one urinary tract infection and one hematuria) while two patients in UGA group experienced perioperative urinary tract infection. None in both groups received blood transfusion. The patients undergoing EUGA had shorter renal access time [(4.0±0.7) min vs. (6.8±2.6) min, P < 0.01] and less repeat puncture (0 vs. 4 cases, P < 0.05).

CONCLUSION

EUGA is an optimal technique to establish percutaneous renal access in ECIRS, which minimizes access time and repeated procedures.

[Interventional treatment of hemorrhage after percutaneous nephrolithotomy]

OBJECTIVE

To evaluate the effectiveness of super-selective renal artery embolization in treatment of post-percutaneous nephrolithotomy bleeding, and to analyse the causes of failure embolization.

METHODS

In the study, 65 post-percutaneous nephrolithotomy patients with severe renal bleeding and hemodynamic instability were treated by super-selective renal artery embolization. First of all, we performed selective renal arteriography. After clarifying the location of the bleeding, superselective intubation of the injured vessel with a microcatheter was carried out. Then the injured vessel was embolized with Tornado micro-coil. When complete embolization was not achieved with micro-coil, a small amount of gelatin sponge particles were added. If there was no positive finding of the beginning selective renal arteriography, the following measures could be taken to prevent missing lesions: (1) Abdominal aorta angiography was performed to determine whether there were anatomical variations, such as accessory renal arteries or multiple renal arteries; (2) Ultra-selective intubation angiography next to the nephrostomy tube path was performed; (3) Renal arteriography was repeated; (4) Renal arteriography after removing the nephrostomy tube while retaining the puncture channel. We evaluated the different angiographic findings and analysed the causes of embolization failure.

RESULTS

Bleeding was successfully controled in 60 patients (62 kidneys) whose renal arteriography was postive. Positive findings included: pseudoaneurysm formation, patchy contrast extravasation, pseudoaneurysm combined with arteriovenous fistula, contrast agent entering the collection system, extravascular perinephric leakage of contrast. After first embolization, bleeding was controled in 53 patients (55 kidneys). The success rate after the first and second embolization was 88.7% and 96.7% respectively. The second session was required because of failure to demonstrate bleeding arteries during the first session (4 patients, 57.1%) and recurrent hemorrhage of the embolized injured arteries (2 patients, 28.6%). In 5 patients with no positive findings, after conservative treatment, hematuria disappeared. All the patients were followed up for 3, 6, and 12 months after embolization, and no hematuria occurred again, and no sustained and serious renal insufficiency.

CONCLUSION

Super-selective renal artery embolization is an effective treatment for post percutaneous nephrolithotomy bleeding. The main cause of failure is omitting of injured arteries during renal arteriography. Renal artery branch injury has various manifestations. Attention should paid to the anatomical variation of the renal artery, and patient and meticulous superselective intubation angiography is the key to avoiding missing the lesion and improving the success rate of embolization.

[Prevention of infectious and inflammatory complications after percutaneous nephrolithotomy]

INTRODUCTION

Given the increase in antibiotic resistance of uropathogens, one of the urgent problems is a development of optimal antimicrobial prophylaxis for surgical interventions, as well as an adequate regimen of antibiotic therapy after percutaneous nephrolithotomy (PCNL).

AIM

to determine an effective perioperative antimicrobial prophylaxis for PCNL in patients with kidney stones.

MATERIAL AND METHODS

A total of 90 patients with staghorn or multiple large kidney stones who underwent PCNL were included in the study. Before PCNL, urine culture was performed in all patients in order to determine the sensitivity not only to antibiotics, but also to bacteriophages. In addition, urine was taken for additional microbiological studies after the puncture of the collecting system, as well as on the 3rd and 7th day after PCNL. All patients were divided into three groups of 30 patients depending on the regimen of perioperative prophylaxis. In group 1, patients were prescribed ciprofloxacin 1000 mg i.v. intraoperatively, then 1000 mg i.v. q.d. for 3-5 days. In the group 2, patients received one dose of cefotaxime + sulbactam (1.0 g + 0.5 g) 2 hours before PCNL i.m. In the group 3, a polyvalent pyobacteriophage purified was given orally 1 hour before PCNL in a dose of 40 ml and the same dose was used t.i.d. for 3-5 days postoperatively.

RESULTS

In all three groups of patients, the following infectious complications were evaluated: acute pyelonephritis, systemic inflammatory response syndrome (SIRS) and urosepsis. There were no serious infectious and inflammatory complications in the early postoperative period among all patients. SIRS developed on days 1-3 after PCNL in 26.6%, 20% and 20% of patients in group 1, 2 and 3, respectively. However, by days 4-7 after PCNL, there was normalization of blood cells count (leukocytes, neutrophil band cells), temperature and general condition.

CONCLUSION

Different regimens of antimicrobial prophylaxis for PCNL have the same efficiency. The development of SIRS on days 1-3 after PCNL is correlated not only with the antimicrobial agents used and the route of their administration (intravenously, intramuscularly and orally). Most likely, the development of SIRS is more associated with surgical trauma.