Oral preparation of hyaluronic acid, chondroitin sulfate, N-acetylglucosamine, and vitamin C improves sexual and urinary symptoms in participants with recurrent urinary tract infections: a randomized crossover trial.

BACKGROUND: Intravesical instillation of hyaluronic acid (HA) has been associated with reduced sexual dysfunction in participants with recurrent urinary tract infections (rUTIs), but the efficacy of an oral treatment has never been investigated. AIM: To investigate the efficacy of an oral preparation of HA, chondroitin sulfate, N-acetylglucosamine, and vitamin C in improving sexual and urinary symptoms in a cohort of reproductive-age participants with rUTI. METHODS: In a monocentric randomized crossover pilot trial, participants with rUTI who were referred to our institute between March 2022 and April 2023 were randomized 1:1 in 2 groups: intervention vs control. All participants had an oral preparation of cranberry, D-mannose, propolis extract, turmeric, and Boswellia twice a day for 3 months. The intervention group also included an oral preparation of HA, chondroitin sulfate, N-acetylglucosamine, and vitamin C once a day for 3 months. Crossover of treatment occurred at 3 months for an additional 3 months. At baseline and 3 and 6 months, participants were evaluated clinically and with the International Prostate Symptom Score (IPSS) and Female Sexual Function Index (FSFI). Descriptive statistics and logistic regression models tested the impact of the intervention on urinary and sexual symptoms at each follow-up assessment. OUTCOMES: Improvement in sexual and urinary symptoms as measured by the FSFI and IPSS. RESULTS: Overall, 27 (54%) participants had an FSFI score <26.5 at enrollment. At 3 months, FSFI scores were higher in the intervention group vs control (P < .001), but IPSS scores were lower (P = .03). After crossover of treatment, FSFI and IPSS scores remained stable in the intervention group. However, after crossover, the control group showed a significant improvement in IPSS and FSFI scores (all P < .01) vs the 3-month assessment. At last follow-up, urinary and sexual symptoms were comparable between groups. In logistic regression analyses, the intervention group was associated with early improvement in sexual symptoms (odds ratio, 3.9; P = .04) and urinary symptoms (odds ratio, 5.1; P = .01) after accounting for clinical confounders. CLINICAL IMPLICATIONS: Combination treatment with HA, chondroitin sulfate, N-acetylglucosamine, and vitamin C is effective if started immediately or even after a few months from symptoms in participants with rUTI. STRENGTHS AND LIMITATIONS: The main limitation is the lack of long-term follow-up. CONCLUSION: The oral formulation of HA, chondroitin sulfate, N-acetylglucosamine, and vitamin C could be an effective therapy against urinary and sexual distress in participants with rUTI (NCT06268483; ClinicalTrials.gov).

Assessment of Effectiveness and Safety of Aspiration-Assisted Nephrostomic Access Sheaths in PCNL and Intrarenal Pressures Evaluation: A Systematic Review of the Literature.

Background: Different suction-assisted nephrostomic sheaths have been developed for percutaneous nephrolithotomy (PCNL). Objectives: (1) To examine PCNL techniques performed with different aspiration-assisted sheaths (Clear Petra® sheath, Superperc, SuperminiPCNL, and a miniPCNL patented sheath), with specific regard to effectiveness and safety outcomes in adult and paediatric patients; (2) to extrapolate intrarenal pressure (IRP) data during these procedures. Methods: A systematic literature search was performed in accordance with PRISMA guidelines. Relevant articles up to 8 February 2024 were included. Results: Twenty-five studies were selected, thirteen retrospective and twelve prospective. The use of four different aspirating sheaths for miniPCNL was reported: Clear Petra® sheath, Superperc, SuperminiPCNL, and a miniPCNL patented sheath. Stone free rates (SFRs) across techniques ranged from 71.3% to 100%, and complication rates from 1.5% to 38.9%. Infectious complication rates varied from 0 to 27.8% and bleeding complication rates from 0 to 8.9%. Most complications were low grade ones. The trend among studies comparing aspiration- and non-aspiration-assisted miniPCNL was towards equivalent or better SFRs and lower overall infectious and bleeding complication rates in suction techniques. Operation time was consistently lower in suction procedures, with a mean shortening of the procedural time of 19 min. Seven studies reported IRP values during suction miniPCNL. Two studies reported satisfactory SFRs and adequate safety profiles in paediatric patient cohorts. Conclusions: MiniPCNL with aspirating sheaths appears to be safe and effective in both adult and paediatric patients. A trend towards a reduction of overall infectious and bleeding complications with respect to non-suction procedures is evident, with comparable or better SFRs and consistently shorter operative times. The IRP profile seems to be safe with the aid of aspirating sheaths. However, high quality evidence on this topic is still lacking.

Extended pelvic lymph node dissection during robotic prostatectomy: antegrade versus retrograde technique.

BACKGROUND: Robot-assisted radical prostatectomy (RARP) with extended lymphadenectomy (ePLND) is the gold standard for surgical treatment of prostate cancer (PCa). Recently, the en-bloc ePLND has been proposed but no studies reported on the standardization of the technique. The aim of the study is to describe different standardized en-bloc ePLND, the antegrade and the retrograde ePLND, and to compare their surgical and oncological outcomes. MATERIALS & METHODS: From January 2018 to September 2019, all patients subjected to RARP plus ePLND by one single surgeon were enrolled. ePLND was performed in a retrograde fashion by starting laterally to the medial umbilical ligament from the internal inguinal ring proceeding towards the ureter, or in an antegrade way by starting from the ureter at its crossing with the common iliac artery and proceeding towards the femoral canal. Patients' demographic data, clinical and surgical data were collected. Each en-bloc ePLND was categorized as "efficient" or "inefficient" by the operator, as surrogate of surgeon's satisfaction. RESULTS: Antegrade and retrograde ePLND were performed in 41/105 (group A) and 64/105 (group R) patients, respectively. The two groups (A vs R) had similar median (IQR) number of lymph nodes retrieved [20 (16.25-31.5) vs 19 (15-26.25); p = 0.18], ePLND time [33.5 (29.5-38.5) min vs 33.5 (26.5-37.5) min; p = 0.4] and post-operative complications [8/41 (19.5%) vs 9/64 (14.1%); p = 0.61]. In group A, 3/41 (7.3%) clinically significant lymphoceles were reported, while 1/64 (1.6%) in group R (p = 0.3). 33/41 (80.5%) and 28/64 (44%) procedures were scored as efficient 59 in group A and R, respectively (p = 0.01). On multivariate regression, only BMI (B = 0.93; 95% CI 0.29-1.56; p = 0.005) was associated with a longer ePLND time. CONCLUSIONS: The study indicates that antegrade and retrograde en-bloc extended pelvic lymph node dissection (ePLND) have comparable surgical and oncologic outcomes, supporting the importance of standardizing the procedure rather than focusing on the direction. Although both techniques aligned with current evidence regarding lymph node invasion and complications, the antegrade approach was subjectively perceived as safer due to early isolation of critical anatomical landmarks. Encouragement for the use of en-bloc ePLND, regardless of direction, is emphasized to improve prostate cancer staging accuracy and procedural standardization.

Vacuum-assisted mini-percutaneous nephrolithotomy is associated with lower rates of infectious complications compared to vacuum-cleaner procedure in patients at high risk for infections: a single-center experience.

PURPOSE: To evaluate the impact of vacuum-assisted mini-percutaneous nephrolithotomy (vamPCNL) vs. vacuum-cleaner mPCNL (vcmPCNL) on the rate of postoperative infectious complications in a cohort of patients with high risk factors for infections. METHODS: We retrospectively analysed data from 145 patients who underwent mPCNL between 01/2016 and 12/2022. Patient's demographics, stones characteristics and operative data were collected. vamPCNL and vcmPCNL were performed based on the surgeon's preference. High-risk patients were defied as having ≥ 2 predisposing factors for infections such as a history of previous urinary tract infections, positive urine culture before surgery, stone diameter ≥ 3 cm, diabetes mellitus and hydronephrosis. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications. RESULTS: vamPCNL and vcmPCNL were performed in 94 (64.8%) and 51 (35.2%) cases, respectively. After surgery, infectious complications occurred in 43 (29.7%) participants. Patients who developed infectious complications had larger stone volume (p = 0.02) and higher rate of multiple stones (p = 0.01) than those who did not. Infectious complications occurred more frequently after vcmPCNL than vamPCNL (55.9% vs. 44.1%. p = 0.01) in high-risk patients. Longer operative time (p < 0.01) and length of stay (p < 0.01) were observed in cases with infectious complications. At multivariable logistic regression analysis, longer operative time (OR 1.1, p = 0.02) and vcmPCNL (OR 3.1, p = 0.03) procedures were independently associated with the risk of infectious complications post mPCNL, after accounting for stone volume. CONCLUSION: One out of three high-risk patients showed infectious complications after mPCNL. vamPCL and shorter operative time were independent protective factors for infections after surgery.

Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study.

PURPOSE: To evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones. METHODS: We analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient's demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization. RESULTS: Overall, median (IQR) age and stone volume were 56 (47-65) years and 1.7 (0.8-4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time. CONCLUSION: One out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Prevalence and predictors of stone passage after double J stenting for symptomatic ureteral stones: a cross-sectional, real-life study.

PURPOSE: To evaluate the rate of and predictors of stone passage (SP) after urgent retrograde stenting for symptomatic ureteral stones. METHODS: We retrospectively analysed data from 249 consecutive patients presenting to the emergency department for symptomatic ureteral stones and treated with retrograde stenting. Demographic, clinical and laboratory characteristics were collected. Stones parameters were collected before stenting and SP was evaluated at 1 month with computerized tomography. Descriptive statistics and logistic regression models tested the association between predictors and SP. RESULTS: Overall, median (IQR) age and stone diameter were 56 (45-68) years and 7.1 (4.4-9.8) mm, respectively. Stones were located in the proximal, mid and distal ureter in 102 (41.0%), 48 (19.3%) and 99 (39.8%) cases. SP was observed in 65 (26.2%) individuals. Stone diameter (3.2 vs. 7.7 mm, p < 0.001) and stone density (416 vs. 741, p < 0.001) were lower and a higher rate of distal stones (76.9% vs. 26.7%, p < 0.001) was found in the SP group compared to that with persistent stones. Multivariable logistic regression analysis showed that distal ureteral stone location (OR 7.9, p < 0.01) and lower HU (OR 0.9, p < 0.01) were associated with SP, after accounting for stone volume. Patients with a distal stone of 500 HU had a 75% probability of SP. CONCLUSION: Stone passage occurred in 26% of patients with indwelling stent due to symptomatic ureteral stones. Lower stone density and distal stone location were independent predictors of stone passage. Patients with these criteria should be managed with follow-up imaging and stent removal instead of ureteroscopy.

Clinical and time-related predictors of sepsis in patients with obstructive uropathy due to ureteral stones in the emergency setting.

PURPOSE: Well-defined clinical predictors of sepsis after upper tract drainage for obstructive uropathy due to ureteral stones are needed. We aim to determine whether sepsis after decompression of the upper urinary tract may be predicted by clinical and time-related factors, specifically delay time from symptom onset to hospital presentation (StH) and from hospital presentation to surgical decompression (HtD). METHODS: In this single-center retrospective study, data from 196 consecutive patients presenting to the emergency department for obstructive uropathy due to ureteral stones and submitted to surgical decompression were evaluated. Postoperative sepsis was defined as an acute increase in ≥ 2 SOFA points and documented blood or urine cultures. RESULTS: Median StH and HtD were 24 (6-48) and 17 (10-30) hours, respectively. Thirty-three (16.8%) patients developed sepsis. Septic patients were more frequently female (75.8% vs. 37.4%, p < 0.001), had higher preoperative max body temperature (p < 0.001), white blood cells (WBC) count (p < 0.01), C-reactive protein (CRP) values (p < 0.001) and larger stone diameter (7.2 vs. 6 mm, p = 0.02). StH and HtD did not differ according to sepsis status. Time for WBC normalization and CRP halving were longer for septic patients (all p < 0.02). At multivariable logistic regression analysis, max body temperature ≥ 38 °C (OR 21.5; p < 0.001), female gender (OR 3.6; p = 0.02) and higher CRP (OR 1.1; p < 0.001) were independently associated with sepsis status. CONCLUSION: Clinical and laboratory parameters are associated with an increased risk of sepsis after decompression. StH and HtD timing are not associated with higher sepsis rates. In selected patients, urinary decompression could be delayed or primary ureteroscopy could be considered.

The clinical role of bacteremia and bacterial spread into the irrigation fluid during percutaneous nephrolithotomy: a prospective study.

PURPOSE: Backflow of pathogens and endotoxins from the renal pelvis to the bloodstream is one supposed mechanism for infectious complications development after endourological stones surgery. The aim of this study is detecting to prove bacterial spread into irrigation fluid and bloodstream during percutaneous nephrolithotomy (PCNL) and to correlate these findings with clinical and microbiological parameters and infectious complications (IC). METHODS: Bladder urine culture (BUC) was retrieved before PCNL; during the procedure, 2 blood samples (BC) and an irrigation fluid sample during fragmentation (SFUC) were collected for culture. Stone culture (SC) was also obtained. Patients were evaluated post-operatively for IC. RESULTS: Sixty-one patients were prospectively included. IC occurred in 15 patients (24.6%). SFUC was positive in 7/61 (11.5%); BC in 10/61 (16.4%). Among patients with positive BC; BUC, SFUC and SC were positive in 9 (90%), 6 (60%), and 8 (80%) cases, respectively. Out of 10 patients with positive BC, 4 developed post-operative IC. Pre-operative renal impairment (p = 0.04), intraoperative-evaluated stone residual (p = 0.02), BUC (p = 0.004), and SC (p = 0.008) were associated with IC. No correlation was found between bacterial spread in the irrigation fluid and blood and IC. CONCLUSION: We proved that bacteria can be detected into the irrigation fluid and blood during PCNL. This transient bacteremia appears to be unrelated to IC development.

Validation of the Trifecta Scoring Metric in Vacuum-Assisted Mini-Percutaneous Nephrolithotomy: A Single-Center Experience.

Background: Scoring metrics to assess and compare outcomes of percutaneous nephrolithotomy (PCNL) are needed. We aim to evaluate prevalence and predictors of trifecta in a cohort of patients treated with vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) for kidney stones. Methods: Data from 287 participants who underwent vmPCNL were analysed. Patients' and stones' characteristics as well as operative data were collected. Stone-free was defined as no residual stones. The modified Clavien classification was used to score postoperative complications. Trifecta was defined as stone-free status without complications after a single session and no auxiliary procedures. Descriptive statistics and logistic regression models tested the association between predictors and trifecta outcome. Results: After vmPCNL, 219 (76.3%) patients were stone-free, and 81 (28.2%) had postoperative complications (any Clavien). Of 287, 170 (59.2%) patients achieved trifecta criteria. Patients who achieved trifecta status had smaller stone volume (p < 0.001), a higher rate of single stones (p < 0.001), shorter operative time (p < 0.01), and a higher rate of single percutaneous tract (p < 0.01) than −trifecta patients. Trifecta status decreased with the number of calyces involved, being 77.1%, 18.8%, and 4.1% in patients with 1, 2, or 3 calyces with stones, respectively (p < 0.001). Multivariable logistic regression analysis showed that stone volume (OR 1.1, p = 0.02) and multiple calyces being involved (OR 2.8 and OR 4.3 for two- and three-calyceal groups, respectively, all p < 0.01) were independent unfavourable risk factors for trifecta after accounting for age, BMI, gender, operative time, and number of access tracts. Conclusions: Trifecta status was achieved in 6 out of 10 patients after vmPCNL. Stone distribution in multiple calyceal groups and stone volume were independent unfavourable risk factors for trifecta.

Is There Still a Place for Percutaneous Nephrolithotomy in Current Times?

Background: Percutaneous nephrolithotomy (PCNL) and its miniaturized modifications are usually considered the standard surgical options for large (>20 mm) staghorn and infected stones. Moreover, PCNL is a viable alternative to retrograde intrarenal surgery (RIRS) for smaller stones (<20 mm) in the presence of anatomical malformations or inaccessible lower pole stones. However, due to the advancements in laser and scope technology, RIRS is expanding its indications with the potential benefits of lower complications and a shorter hospital stay. Methods: A literature search using the PUBMED database from inception to June 2022 was performed to explore the current role of PCNL in endourology. The analysis involved a narrative synthesis. Results: PCNL confirmed its role in the treatment of large and complex stones; moreover, miniaturized PCNL has become more competitive, gaining space among classic indications of flexible ureteroscopy. Conclusions: considering all the evaluated subgroups, we can conclude that PCNL is an old fascinating procedure and is here to stay.

Urologists are optimistic surgeons: prevalence and predictors of discordance between intraoperative stone-free rate and cross-sectional imaging evaluation after vacuum-assisted mini-percutaneous nephrolithotomy.

PURPOSE: To assess how accurate are urologists in predicting stone-free status (SFS) after vacuum-assisted mini-PCNL (vamPCNL) compared to computed tomography (CT) and clinical predictors of discordant SFS. METHODS: Data from 235 patients who underwent vamPCNL were analysed. Patient's demographics, stones' characteristics and operative data were recorded. SFS was evaluated intraoperatively by the treating urologist (iSFS) and with non-contrast CT 3 months after vamPCNL (ctSFS). SFS was defined as no residual stones. Stone complexity was scored with the Guy's score. Descriptive statistics and logistic regression models were used to identify clinical factors associated with discordant SFS (namely iSFS not confirmed at CT). RESULTS: iSFS and ctSFS were 88.5% and 65.5%, respectively, with 54 (23%) cases resulting in discordant evaluation of SFS between the surgeon and CT imaging. Patients with discordant SFS had larger stone volume (p < 0.001), higher rate of multiple stones (p = 0.03) and higher rate of multiple calyceal groups affected by stones (p < 0.001) than those with concordant SFS. The use of flexible ureteroscopes to look for residual stones after lithotripsy was more frequently reported in cases with concordant SFS (p = 0.001). Multivariable logistic regression analysis revealed that stones in > 2 calyceal groups (OR 10.2, p < 0.001), Guy's score II (OR 5.8, p < 0.01) and not using flexible ureteroscopes after lithotripsy (OR 2.9, p = 0.02) were independent predictors of discordant SFS. CONCLUSION: One out of five patients is erroneously considered SF after vamPCNL. Urologist should carefully evaluate patients with multiple calyceal stones and consider using flexible ureteroscopes to complete lapaxy of migrated fragments in order to improve their prediction of SFS.

Pediatric Urolithiasis: Current Surgical Strategies and Future Perspectives.

New technological innovations and cutting-edge techniques have led to important changes in the surgical management of pediatric urolithiasis. Miniaturized technologies and minimally invasive approaches have been increasingly used in children with urinary stones to minimize surgical complications and improve patient outcomes. Moreover, the new computer technologies of the digital era have been opening new horizons for the preoperative planning and surgical treatment of children with urinary calculi. Three-dimensional modeling reconstructions, virtual, augmented, and mixed reality are rapidly approaching the surgical practice, equipping surgeons with powerful instruments to enhance the real-time intraoperative visualization of normal and pathological structures. The broad range of possibilities offered by these technological innovations in the adult population finds increasing applications in pediatrics, offering a more detailed visualization of small anatomical structures. This review illustrates the most promising techniques and devices to enhance the surgical treatment of pediatric urolithiasis in children, aiming to favor an early adoption and to stimulate more research on this topic.

The comprehensive complication index as a tool for reporting the burden of complications after mini-percutaneous nephrolithotomy: is it time to leave the Clavien-Dindo classification behind?

PURPOSE: To validate the comprehensive complication index (CCI) for mini-percutaneous nephrolithotomy (mPCNL). METHODS: Data from 287 patients who underwent mPCNL were analyzed. Complications after mPCNL were classified using both the CCI and the Clavien-Dindo classification (CDC). Descriptive statistics and linear/logistic regression analyses detailed the association between clinical predictors and mPCNL outcomes. RESULTS: After mPCNL, 83 (28.9%) patients had complications, of which 12 (4.2%) patients with multiple complications had a higher CCI score compared to the traditional CDC system accounting only for the highest grade. The CCI enabled a more accurate prediction of length of stay (LOS) than CDC (CCI: r = 0.32; p < 0.01 vs. CDC: r = 0.26; p = 0.01). Patients with multiple complications had higher stone volume (p = 0.02), longer operative time and LOS (all p < 0.01). A higher rate of post-operative hospital readmission (33.3% vs. 9.9%, p = 0.02) and lower rate of stone free (33.3% vs. 64.7%, p = 0.04) were found in patients with multiple complications than in those with single complication. Linear regression analysis revealed that multiple complications were associated with longer LOS (p < 0.001) after accounting for BMI and stone volume. Similarly, having multiple complications was associated with fivefold higher risk of readmission (p = 0.02). CONCLUSION: The CCI is a valuable metric for assessing post-operative complications after mPCNL. The cumulative CCI is a better predictor of LOS than the CDC for mPCNL. Minor complications not captured by the highest CDC score are relevant since patients with multiple complications have longer LOS and higher rate of readmission than those with single ones.

Cost analysis between mini-percutaneous nephrolithotomy with and without vacuum-assisted access sheath.

PURPOSE: To perform a cost analysis between vacuum-assisted percutaneous nephrolithotomy (vmPCNL) and minimally invasive PCNL (MIP) and explore potential predictors of costs associated with the procedures. METHODS: We analyzed data from 225 patients who underwent vmPCNL or MIP at a single tertiary referral academic center between January 2016 and December 2020. We collected patients' demographics, peri-and postoperative data and detailed expense records. After propensity score matching, 108 (66.7%) vmPCNL and 54 (33.3%) MIP procedures were analyzed. Descriptive statistics assessed differences in clinical and operative parameters. Univariable and multivariable linear regression models tested the association between clinical variables and costs. RESULTS: Operative time (OT) was shorter for vmPCNL, and the use of additional instruments to complete litholapaxy was more frequent in MIP (all p ≤ 0.01). Length of stay (LOS) was longer for MIP patients (p = 0.03) and the stone-free (SF) rate was higher after vmPCNL (p = 0.04). The overall instrumentation cost was higher for vmPCNL (p < 0.001), but total procedural costs were equivalent (p = 0.9). However, the overall cost for the hospitalization was higher for MIP than vmPCNL (p = 0.01). Univariable linear regression revealed that patient's comorbidities, OT, any postoperative complication and LOS were associated with hospitalization costs (all p < 0.001). Multivariable linear regression analysis revealed that LOS and OT were associated with hospitalization costs (all p < 0.001), after accounting for vmPCNL procedure, patients' comorbidities, and complications. CONCLUSION: vmPCNL may represent a valid option due to clinical and economic benefits. Shorter OT, the lower need for disposable equipment and the lower complication rate reduced procedural and hospitalization costs.

The Matryoshka technique in percutaneous nephrolithotomy.

OBJECTIVE: Miniaturized percutaneous nephrolithotomy (PCNL) reduces the risk of haemorrhagic complications, but the limited field of work represents a drawback. To obtain the best outcomes, the percutaneous access size should be intraoperatively tailored. Our purpose is to describe the indications and the procedural steps of the Matryoshka technique and to report its clinical outcomes. MATERIALS AND METHODS: We performed a retrospective analysis of the data from consecutive Matryoshka PCNL procedures from October 2016 to January 2018. Collected data included patients' history, stone characteristics, intra- and post-operative items, stone clearance and need for retreatment. The main indication to the Matryoshka technique is the inability to securely position a guidewire due to an obstruction or narrowness in the pyelocalyceal system. This technique begins by puncturing the calyx hosting the stone and advancing a hydrophilic guidewire through the needle. If the guidewire cannot proceed beyond the stone, the Matryoshka technique is employed for tract stabilization. The tract is carefully dilated with small-bore instruments and a cautious lithotripsy is performed to create enough space to introduce the guidewire beyond the stone under visual control. Once the access has been stabilized the surgeon can upsize the tract to the optimum to complete the procedure. Additionally, the technique can be employed when an intraoperative reassessment induces the surgeon to further dilate the tract to quicken the procedure. RESULTS: Sixteen patients were included, with a median stone volume of 3.49 cm3. Median operative time was 112 minutes. Three Clavien I-II (postoperative fever) and one Clavien IIIB (colon perforation) complications were reported. No blood transfusions were recorded. Three patients underwent scheduled retreatment as part of a multistep procedure. Out of the remaining 13 patients, 10 (76.9%) obtained a complete stone clearance. CONCLUSIONS: The Matryoshka technique helps the urologist to obtain a secure percutaneous access and makes PCNL flexible and progressive, potentially minimizing the risk of access-related complications.

Semi-closed-circuit vacuum-assisted MiniPCNL system in pediatric patients.

Surgical treatment of kidney stones has changed over the years. The use of Mini Percutaneous Nephrolithotomy (MiniPCNL) instrumentation is associated with a reduction of major complications but it lengthens the operative time (OT). This limit may be overcome by a semi-closed-circuit vacuum-assisted MiniPCNL system, characterized by a continuous inflow and a suction-controlled outflow. We present our initial experience in pediatric patients who underwent PCNL using a 12 Fr nephroscope and a 16-Fr-large nephrostomy sheath, equipped with a lateral arm connected to suction. We used Holmium laser lithotripsy and performed lapaxy by drawing back slowly the nephroscope inside the sheath until the opening of the lateral aspiration arm, without using other devices. The stone-free rate (SFR) was assessed at 4 weeks. We included 12 procedures in 8 patients with a median age of 119 months and a median weight of 27 Kg. The median OT was 108 min and the SFR was 80%. No intra-operative complications occurred, while minor post-operative complications occurred after 4/12 procedures. These preliminary data in pediatric population showed the employed system is a safe and effective approach to treat complex kidney stones with a satisfactory SFR and a low OT.

Clinical Comparison of Mini-Percutaneous Nephrolithotomy with Vacuum Cleaner Effect or with a Vacuum-Assisted Access Sheath: A Single-Center Experience.

Purpose: To compare outcomes of two different miniaturized percutaneous nephrolithotomy (PCNL) techniques: minimally invasive PCNL (MIP) with the vacuum cleaner effect and vacuum-assisted mini-PCNL (vmPCNL). Materials and Methods: Data from 104 (66.7%) patients who underwent vmPCNL and 52 (33.3%) patients who underwent MIP at a single tertiary referral academic center between January 2016 and December 2019 were analyzed. Patient demographics and peri- and postoperative data were recorded, and propensity score matching was performed. Descriptive statistics and linear regression models were used to identify variables associated with operative time (OT) and patient effective dose. Logistic regression analyses were used to identify factors associated with infectious complications and stone-free (SF) status. Results: Patient demographics and stone characteristics were comparable between groups. vmPCNL was associated with shorter OT (p < 0.001), fluoroscopy time, and patient effective dose (4.2 mSv vs 7.9 mSv; p < 0.001). A higher rate of infectious complications was found in the MIP group (25.0% vs 7.7%, p < 0.01). Linear regression analysis showed that stone volume, multiple stones, and MIP procedure (all p values ≤0.02) were associated with longer OT. Similarly, OT and the MIP procedure (p ≤ 0.02) were associated with higher patient effective dose. Logistic regression analysis revealed that the stone volume, positive preoperative bladder urine culture, and MIP procedure (all p values ≤0.02) were associated with postoperative infectious complications. vmPCNL was not associated with the SF rate. Conclusions: Mini-PCNL performed with continuous active suction is associated with lower rates of infectious complications, shorter OT, and lower patient effective dose than MIP.

Vacuum-assisted mini-percutaneous nephrolithotomy: a new perspective in fragments clearance and intrarenal pressure control.

PURPOSE: To describe the vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) technique performed via the 16Ch ClearPetra sheath, to evaluate its outcomes and to analyze intrarenal pressure (IRP) fluctuations during surgery. METHODS: Data from all consecutive vmPCNL procedures from September 2017 to October 2019 were prospectively collected. Data included patients' and stones characteristics, intra and peri-operative items, post-operative complications and stone clearance. Patients undergoing vmPCNL from March to October 2019 were submitted to IRP measurement during surgery. RESULTS: A total of 122 vmPCNL procedures were performed. Median stone volume was 1.92 cm3. Median operative time was 90 min and median lithotripsy and lapaxy time was 28 min. Stone clearance rate was 71.3%. Thirty-one (25.2%) patients experienced post-operative complications, seven of which were Clavien 3. Postoperative fever occurred in nine (7.4%) patients and one (0.8%) needed a transfusion. No sepsis were observed. IRPs were measured in 22 procedures. Mean IRP was 15.3 cmH2O and median accumulative time with IRP > 40.78 cmH2O (pyelovenous backflow threshold) was 28.52 sec. Maximum IRP peaks were reached during the surgical steps when aspiration is closed (mainly pyelograms), whereas during lithotripsy and suction-mediated lapaxy, the threshold of 40.78 cmH2O was overcome in three procedures. CONCLUSIONS: vmPCNL is a safe procedure with satisfactory stone clearance rates. Mean IRP was always lower than the threshold of pyelo-venous backflow and the accumulative time with IRP over this limit was short in most of the procedures. During lithotripsy and vacuum-mediated lapaxy, IRP rarely raised over the threshold.

Impact of Surgical Experience on Radiation Exposure during Retrograde Intrarenal Surgery: A Propensity-Score Matching Analysis.

BACKGROUND: The impact of surgical experience on radiation exposure (RE) during endourological procedures has been poorly investigated. OBJECTIVE: To assess the impact of surgical experience on fluoroscopy time (FT) and RE during retrograde intrarenal surgery (RIRS). DESIGN, SETTING, AND PARTICIPANTS: The study included 140 patients who underwent RIRS performed either by a senior surgeon (expertise of >100 RIRSs) (group A) or by two junior residents (expertise of <15 RIRSs) (group B) between January 2016 and May 2018. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We tested the hypothesis that surgical experience had a limited impact on RE during RIRS. To adjust for potential baseline confounders, propensity-score matching was performed. Descriptive statistics and linear regression models tested the association between clinical variables and FT and patients' effective doses. RESULTS AND LIMITATIONS: There was no significant difference between the two groups for baseline, intraoperative, and postoperative characteristics. Overall FT (p=0.97) and effective dose (p=0.79) did not differ between groups. A statistically significant association was found between male sex (all p<0.03), stone burden (all p<0.001), operative time (all p<0.003), and postoperative double-J placement (all p<0.02) with both FT and effective dose. Linear multivariable analysis revealed that body mass index was significantly associated with effective dose (p=0.002). Similarly, longer operative time (all p<0.03) and double-J placement (all p<0.04) were significantly associated with increased FT and effective dose. CONCLUSIONS: Surgical experience has a limited impact on FT and RE during RIRS. Longer operative time and double-J placement were associated with increased FT and effective dose. PATIENT SUMMARY: In this study, we assessed whether surgical experience affects fluoroscopy time and patient's effective dose during retrograde intrarenal surgery (RIRS). We found that radiation exposure (RE) was not affected by surgeon's experience and that the standardisation of the surgical technique at the beginning of the learning curve of young surgeons may represent the key factor in reducing RE during RIRS.