Double-J stent placement during laparoscopic ureterolithotomy: the "seagull" technique.

OBJECTIVE: To present a new technique of double-j stent (DJ) placement during laparoscopic transperitoneal ureterolithotomy (LUL). PATIENTS AND METHODS: Following the extraction of the stone, a 6 French DJ open-end stent is prepared: two straight-tip hydrophilic guidewires are inserted into the appropriate lateral holes of the stent, as identified by the preoperative evaluation of the CT scan. Approximately 5 centimeters of each wire protrude from the proximal and distal ends of the stent to straighten its terminal curl, thus resembling the wings of a flying seagull. The remaining proximal portions of both guide wires are left within each guidewire dispenser. The two ends of the stent are grasped together in a U-fashion and inserted into the abdomen through a 10mm port. Once in the abdomen, the longer segment of the stent is inserted and pushed into the ureterotomy until it reaches the target site. The guide wire is then removed. The same procedure is repeated for the other end of the stent. A brief literature review on the currents techniques of laparoscopic DJ placement is also presented. RESULTS: Analyzing the outcomes of 21 LUL, the "seagull" technique is time-saving and safe. No perioperative complications were encountered. There is no risk of enlarging or tearing the ureterotomy and no need for patient replacement, extra cystoscopic or ureteroscopic procedures as well as of using modified guidewires and closed-tip stents. CONCLUSION: We described our step-by-step technique for DJ placement during LUL.

Phimosis in Adults: Narrative Review of the New Available Devices and the Standard Treatments.

BACKGROUND: Phimosis is the inability to completely retract the foreskin and expose the glans. The treatment of phimosis varies depending on the age of the patient and the severity of the disease; a great number of conservative or surgical treatments are currently available. AIM: To provide the first review summarizing the available options for the treatment of adult phimosis. METHODS: A PubMed, Cochrane and Embase search for peer-reviewed studies, published between January 2001 and December 2022 was performed using the search terms "phimosis AND treatment". RESULTS: A total of 288 publications were initially identified through database searching. Thirty manuscripts were ultimately eligible for inclusion in this review. Conservative treatment is an option. and it includes topical steroid application and the new medical silicon tubes (Phimostop™) application for gentle prepuce dilation. Concerning the surgical approach, the gold-standard treatment is represented by circumcision in which tissue synthesis after prepuce removal can be also obtained with barbed sutures, fibrin glues or staples. Laser circumcision seems to be providing superior outcomes in terms of operative time and postoperative complication rate when compared to the traditional one. Several techniques of preputioplasty and use of in situ devices (which crush the foreskin and simultaneously create haemostasis) have been also described. These in situ devices seem feasible, safe and effective in treating phimosis while they also reduce the operative time when compared to traditional circumcision. Patient satisfaction rates, complications and impact on sexual function of the main surgical treatments are presented. CONCLUSION: Many conservative and surgical treatments are available for the treatment of adult phimosis. The choice of the right treatment depends on the grade of phimosis, results, complications, and cost-effectiveness.

External Validation of the "Tor Vergata" 3D Printed Models of the Upper Urinary Tract and Stones for High-Fidelity Simulation of Retrograde Intrarenal Surgery.

Introduction: Novel training modalities are being investigated to overcome the challenges associated with learning retrograde intrarenal surgery (RIRS). Consequently, a series of 3D printed models of the upper urinary tract and stones designed for ex vivo surgical simulation was introduced in 2021. This study aims to provide external validation of the training model and assess its role in the development of surgical skills. Materials and Methods: A mixed cohort of 20 urologists at different levels of expertise participated in a whole-day live simulation event to examine the model and perform a timed simulation of intrarenal navigation, stone relocation, and laser fragmentation. Operative times were recorded and two independent expert endourologists scored the simulations according to a modified "Objective Structured Assessment of Technical Skills" (OSATS) scale. Five novice urologists from the cohort performed three further simulations in a subsequent event to assess improvement in surgical skills. Results: Face validity was demonstrated with a median score of ≥4/5 in each of the 11 items investigated. Content validity was also effectively reached, with 100% positive impressions with regard to the usefulness for the acquisition of surgical skills. Significant differences were observed among operative times stratified per surgeon experience (all p < 0.0050), thus providing construct validity. Median total OSATS score for novices was 14 (range 8, 25) and was found to be significantly different from expected expert performance (p = 0.0010). Repeated simulations by novices led to a progressive reduction of operative times (p = 0.0313) and increase in median total OSATS (p = 0.0625). Conclusion: The 3D printed models of upper urinary tract and synthetic training stones for the high-fidelity simulation of each phase of RIRS were validated by this study. The results encourage the usage of the models in simulation courses and the evaluation of their potential role in standardized training curricula.

Fournier's gangrene with prostatic and bladder trigone colliquation: a suggested treatment algorithm.

Fournier's gangrene (FG) is an infectious necrotising fasciitis of the perineum and genital regions with a high mortality rate. We report the case of a man in his 70s with FG who presented with bladder trigone and prostate colliquation. Bulbar and penile urethra were also injured with multiple fenestrations. Bilateral percutaneous nephrostomy positioning followed by the placement of occluding ureteral catheters preceded the surgical debridement of the necrotic tissues and protective colostomy. There followed periodic sessions of surgical debridement and VAC therapy. The persistent perineal urinary leak required the crafting of a suprapubic surgical cystostomy with bladder neck obliteration through double-layer raphy. The cystostomy maintained the healing tissues free from the constant and damaging urine action. This report describes the successful multistep approach of an FG with deep involvement and colliquation of the bladder neck and prostate reaching the Denonvilliers fascia that ensured the correct healing of tissues.

Corrigendum: Is urology a gender-biased career choice? A survey-based study of the Italian medical students'; perception of specialties.

[This corrects the article DOI: 10.3389/fsurg.2022.962824.].

Introducing 3D printed models of the upper urinary tract for high-fidelity simulation of retrograde intrarenal surgery.

PURPOSE: Training in retrograde intrarenal surgery for the treatment of renal stone disease is a challenging task due to the unique complexity of the procedure. This study introduces a series of 3D printed models of upper urinary tract and stones designed to improve the training process. METHODS: Six different models of upper urinary tract were algorithmically isolated, digitally optimized and 3D printed from real-life cases. Soft and hard stones in different sizes were produced from 3D printed moulds. The models were fitted onto a commercially available part-task trainer and tested for retrograde intrarenal surgery. RESULTS: Each step of the procedure was simulated with extraordinary resemblance to real-life cases. The unique anatomical intricacy of each model and type of stones allowed us to reproduce surgeries of increasing difficulty. As the case-load required to achieve proficiency in retrograde intrarenal surgery is high, benchtop simulation could be integrated in training programs to reach good outcomes and low complication rates faster. Our models match incredible anatomical resemblance with low production cost and high reusability. Validation studies and objective skills assessment during simulations would allow comparison with other available benchtop trainers and the design of stepwise training programs. CONCLUSIONS: 3D printing is gaining a significant importance in surgical training. Our 3D printed models of the upper urinary tract might represent a risk-free training option to hasten the achievement of proficiency in endourology.

Can circumcision be avoided in adult male with phimosis? Results of the PhimoStopTM prospective trial.

BACKGROUND: Circumcision as surgical treatment of adult phimosis is not devoid of complications. Efficacy of alternative non-surgical options is unclear. PhimoStopTM is a therapeutic protocol which involves the use of appropriately shaped silicone tuboids of increasing size to obtain a non-forced dilation of the prepuce. The aim of the study was to evaluate the efficacy and durability of results of PhimoStopTM device for the treatment of adult male phimosis. METHODS: A prospective trial was conducted between 2018 and 2020 on 85 consecutive adult male patients affected by phimosis and with an indication for circumcision. Patients were treated with PhimoStopTM protocol and they were evaluated at baseline and after treatment through a subjective (patient self-reported information on various domains of his sexual function) and an objective assessment (evaluation of phimosis severity grade according to the Kikiros scale pre- and post-treatment, re-assessment of indication for circumcision post-treatment and validated questionnaires scores). Primary endpoint was to avoid the scheduled circumcision in 33% of the patients enrolled. RESULTS: Seventy-one patients (84%) completed the device usage phase as per study protocol. Median duration of tuboid application was 60 days. Thirty-seven patients (52.1%) had no indication for circumcision after treatment. Even considering patients lost to follow-up as failures, primary endpoint was reached in 43.5% of cases. There was a significant reduction of the grade of phimosis after treatment (P<0.001). Moreover IIEF-5 showed a statistically significant improvement after treatment (P<0.001). Thirty/37 patients who met the primary endpoint (81%) still have a successful resolution of their phimosis avoiding circumcision at a median follow-up of 24 months. CONCLUSIONS: PhimoStopTM device is effective for the treatment of adult male phimosis of Kikiros grade ≤2. The results seem to be durable in most patients at a median follow-up of 24 months. Randomized clinical trials are necessary in order to confirm our results and assess cost-efficacy.

T1 Bladder Cancer: Comparison of the Prognostic Impact of Two Substaging Systems on Disease Recurrence and Progression and Suggestion of a Novel Nomogram.

Background: The T1 substaging of bladder cancer (BCa) potentially impacts disease progression. The objective of the study was to compare the prognostic accuracy of two substaging systems on the recurrence and progression of primary pathologic T1 (pT1) BCa and to test a nomogram based on pT1 substaging for predicting recurrence-free survival (RFS) and progression-free survival (PFS). Methods: The medical records of 204 patients affected by pT1 BCa were retrospectively reviewed. Substaging was defined according to the depth of lamina propria invasion in T1a-c and the extension of the lamina propria invasion to T1-microinvasive (T1m) or T1-extensive (T1e). Uni- and multivariable Cox regression models evaluated the independent variables correlated with recurrence and progression. The predictive accuracies of the two substaging systems were compared by Harrell's C index. Multivariate Cox regression models for the RFS and PFS were also depicted by a nomogram. Results: The 5-year RFS was 47.5% with a significant difference between T1c and T1a (p = 0.02) and between T1e and T1m (p < 0.001). The 5-year PFS was 75.9% with a significant difference between T1c and T1a (p = 0.011) and between T1e and T1m (p < 0.001). Model T1m-e showed a higher predictive power than T1a-c for predicting RFS and PFS. In the univariate and multivariate model subcategory T1e, the diameter, location, and number of tumors were confirmed as factors influencing recurrence and progression after adjusting for the other variables. The nomogram incorporating the T1m-e model showed a satisfactory agreement between model predictions at 5 years and actual observations. Conclusions: Substaging is significantly associated with RFS and PFS for patients affected by T1 BCa and should be included in innovative prognostic nomograms.

Post-Operative Acute Urinary Retention After Greenlight Laser. Analysis of Risk Factors from A Multicentric Database.

PURPOSE: Greenlight laser is a mini-invasive technique used to treat Benign Prostatic Obstruction (BPO). Some of the advantages of GreenLight photoselective vaporization (PVP) are shorter catheterization time and hospital stay compared to TURP. Post-operative acute urinary retention (pAUR) leads to patients' discomfort, prolonged hospital stay and increased health care costs. We analyzed risk factors for urinary retention after GreenLight laser PVP. MATERIALS AND METHODS: In a multicenter experience, we retrospectively analyzed the onset of early and late post-operative acute urinary retention in patients undergoing standard or anatomical PVP. The pre-, intra- and post-operative characteristics were compared betweene patients who started to void and the patients who developed post-operative urinary retention. RESULTS: The study included 434 patients suitable for the study. Post-operative acute urinary retention occurred in 39 (9%). Patients with a lower prostate volume (P < .001), an adenoma volume lower than 40 mL (P < .001), and lower lasing time (P = .013) had a higher probability to develop pAUR at the univariate analysis. The multivariate logistic regression confirmed that lower lasing time (95% CI: 0.86-0.99, OR = 0.93, P = .046) and adenoma volume (95% CI: 0.89-0.98, OR = 0.94, P = .006) are correlated to pAUR. Furthermore IPSS ≥ 19 (95% CI: 1.19- 10.75, OR = 2.27, P = .023) and treatment with 5-ARI (95% CI: 1.05-15.03, OR = 3.98, P = .042) are risk factors for pAUR. CONCLUSION: In our series, post-operative acute urinary retention was related to low adenoma volume and lasing time, pre-operative IPSS ≥ 19 and 5-ARI intake. These data should be considered in deciding the best timing for urethral catheters removal.

Late-onset hemorrhagic cystitis in children after hematopoietic stem cell transplantation for thalassemia and sickle cell anemia: a prospective evaluation of polyoma (BK) virus infection and treatment with cidofovir.

Little is known about late-onset hemorrhagic cystitis (HC) in children, its relationship to BK virus, and treatment with cidofovir (CDV) following hematopoietic stem cell transplantation (HSCT). We prospectively investigated BK virus reactivation in children who underwent HSCT from a matched related donor for thalassemia or sickle cell anemia following busulfan-cyclophosphamide-based conditioning regimens and analyzed risk factors for development of HC and its treatment with CDV. Grade 2-4 HC occurred in 30 patients with a cumulative incidence of 26% (95% confidence interval [CI] = 18%-34%). The cumulative incidences of BK viruria and viremia were 81% (95% CI = 69%-89%) and 28% (95% CI = 18%-40%), respectively. Multivariate analysis revealed that use of antithymocyte globulin (ATG) (hazard ratio [HR] = 10.5; P = .001), peak BK viruria >100,000 copies/mL (HR = 6.2; P = .004), and grade II-IV acute graft-versus-host disease (HR = 5.3; P = .007) were predictive factors for HC. Nineteen patients with HC were given CDV at 1.5 mg/kg/day 3 times a week, or 5 mg/kg/week. The median duration of therapy was 27 days (range, 21-180 days), and a median of 9 doses were given (range, 6-22). All patients had a complete clinical response (CCR), and 69% had a microbiological response at 4 weeks. Eleven patients with BK virus-related HC receiving supportive care also had CCR. The median duration of HC in these patients was similar to that in patients treated with CDV. None of the patients with HC cleared BK viruria when CCR was achieved. We conclude that late-onset HC is more prevalent in children with sustained high BK viruria who are treated with ATG or who develop graft-versus-host disease. Randomized clinical trials are urgently needed to better define the role of CDV in treating BK virus-related HC.

Operative profile, safety and functional outcomes after GreenLight laser prostate surgery: results from a 12 months follow-up multicenter Italian cohort analyses.

BACKGROUND: Over the two past decades, GreenLight laser therapy has been considered a valid alternative for the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia/benign prostatic obstruction (BPH/BPO). However, the debate on the effectiveness of laser therapy compared to conventional techniques is still open. The aim of our study is to analyze and describe the use of GreenLight laser prostate surgery in Italy, with regard to the surgical techniques performed and the surgical and functional outcomes at mid-term follow-up. METHODS: From March 2012 to July 2018, patients who underwent GreenLight laser prostate surgery for LUTS due to BPH/BPO from 19 Italian centers were included. The following parameters were evaluated in the population: age, prostate volume, prostate adenoma volume, PSA tot, Qmax at uroflowmetry (UFM), International Prostatic Symptoms Score (IPSS), previous therapy for LUTS, use of anticoagulants and antiplatelet drugs. We recorded also the kind of anesthesia, mean laser time (min), mean irradiation time (min), TURP conversion/completion rate, postoperative day of catheter removal, postoperative acute urinary retention (AUR), hospital stay, variation of hematocrit (Ht) and hemoglobin levels (Hb). Early complications were classified according to the Clavien-Dindo classification, the re-operation rate within 30 days and after 30 days, the late complications and the Patient Global Impression of Improvement were also collected. Changes over time in terms of blood loss and functional outcomes (IPSS and Qmax at the UFM at 6 and 12 months) were tested with Student's test for paired samples. We assumed P≤0.05 as level of statistical significance. RESULTS: Overall, 1077 were enrolled in the study, 554 (56.4%) were treated with standard vaporization and 523 (48.6%) with anatomical vaporization. Student's t-test for paired samples showed no statistically significant differences in terms of reduction of Ht preoperative vs. Ht postoperative (42.80±3.91 vs. 39.93±5.35 95% CI P=0.3) and preintervention and postintervention Hb levels (14.28±1.46 vs. 13.72 P=0.35). Compared with the preoperative Qmax (8.60±2.64), the 6- and 12-month UFM showed a significant improvement [19.56±6.29, P<0.01 and 19.99±5.92 P<0.01]. In terms of IPSS variation, compared to the baseline level (22±5.51) the 6- and 12-month follow-up confirmed a significant reduction (8.01±4.41 P<0.01 and 5.81±4.12 P<0.01 respectively). Postoperative complications were CD0, CD1, CD2, CD3, CD4 in 33.0%,35.3%, 2.9%, 0.3%, and 0.6%. CONCLUSIONS: To the best of our knowledge, this is one of the most numerous surgical series of GreenLight laser vaporization and with the longest follow-up. This technique should be considered as a safe and effective alternative in the treatment of secondary LUTS to BPH.

GreenLight Photoselective Vaporization of the Prostate: One Laser for Different Prostate Sizes.

Introduction: GreenLight laser vaporization of the prostate (photoselective vaporization of the prostate [PVP]) is a safe and effective procedure for Benign Prostatic Hyperplasia. Long-term results and advantages of PVP in patients with large and symptomatic prostate are still under evaluation. Materials and Methods: In a multicenter experience, patients who underwent standard or anatomical PVP were retrospectively reviewed. Patients with follow-up >12 months were divided into two groups based on prostate volume (<100 cc vs ≥100 cc). Pre- and perioperative data, as well as postoperative results and complications, were recorded after 3, 6, and 12 months and then annually. Results: One thousand and thirty-one patients were eligible, 916 of these had a prostate volume of <100 cc and 115 ≥ 100 cc. Median follow-up period was 25.0 months (interquartile range [IQR] 16.5-35.0) and 16.0 months (IQR 12.0-24.0) in ≥100 and <100 groups, respectively. No difference was found in terms of catheterization time, postoperative stay, and postoperative acute urine retention. Patients with prostate ≥100 required longer operative time (75 vs 55 minutes), lasing time (41.7 vs 24.9 minutes), and higher energy used but lower energy density. Patients with prostate ≥100 had a higher incidence of early (50.4% vs 35.7%) and late complications (21.7% vs 12.8%) and early urge/incontinence symptoms (40.9% vs 29.3%). No statistically significant differences were found for the maximum urinary flow (Qmax) and International Prostate Symptom Score (IPSS) results between the two groups. The reintervention rate in ≥100 group was 3.5% vs 2.3% in <100. Conclusions: In the midterm follow-up, GreenLight PVP guarantees the same results in different prostate volume groups. Early and late complications are more frequent in large prostates.

Multi-institutional Evaluation of Producing and Testing a Novel 3D-Printed Laparoscopic Trainer.

OBJECTIVE: To create, distribute, and evaluate the efficacy of a portable, cost-effective 3D-printed laparoscopic trainer for surgical skills development. METHODS: The UCI Trainer (UCiT) laparoscopic simulator was developed via computer-aided designs (CAD), which were used to 3D-print the UCiT. Once assembled, a tablet computer with a rear-facing camera was attached for video and optics. Four institutions were sent the UCiT CAD files with a 3D-printer and instructions for UCiT assembly. For a comparison of the UCiT to a standard trainer, peg transfer and intracorporeal knot tying skills were accessed. These tasks were scored, and participants were asked to rate their experience with the trainers. Lastly, a questionnaire was given to individuals who 3D-printed and assembled the UCiT. RESULTS: We recruited 25 urologists; none had any 3D-printing experience. The cost of printing each trainer was $26.50 USD. Each institution used the Apple iPad for optics. Six of eight participants assembled the UCiT in < 45 minutes, and rated assembly as somewhat easy. On objective scoring, participants performed tasks equally well on the UCiT vs the conventional trainer. On subjective scoring, the conventional trainer provided a significantly better experience vs the UCiT; however, all reported that the UCiT was useful for surgical education. CONCLUSION: The UCiT is a low cost, portable training tool that is easy to assemble and use. UCiT provided a platform whereby participants performed laparoscopic tasks equal to performing the same tasks on the more expensive, nonportable standard trainer.

Treatment options for benign prostatic hyperplasia in older men.

BACKGROUND: Benign prostatic enlargement (BPE) is one of the most common diseases in ageing men; it is associated with bothersome lower urinary tract symptoms that affect the individual's quality of life. This review focuses on the different available options for treating benign prostatic hyperplasia (BPH) in older men and on how to choose the right treatment. MATERIAL/METHODS: A literature search was done to review relevant papers. Relatively recent papers, as well as those in a series or papers from expert centers, are included in the reference list. RESULTS: Treatment options for BPE in older men include medical therapy, transurethral resection of the prostate (TURP), minimally invasive treatments (ie, transurethral microwave thermotherapy, transurethral needle ablation, and laser surgery) and prostatic stenting. Age, individual anesthesiologic risk, grade of obstruction, prostate volume, serum prostate specific antigen (PSA) value, treatment-related complication rate, presence of an indwelling catheter, and neurologic disorders are factors that should be taken into consideration in choosing an appropriate treatment. CONCLUSIONS: Given the wealth of treatment options available, physicians must take care to choose the right treatment for each patient, depending on the patient's needs and medical history.

The influence of environmental conditions on the incidence of renal colic in Rome.

INTRODUCTION: The aim of this study was to investigate the effect of three major environmental variables (temperature, humidity, air pressure) on the probability of onset of renal colic (RC) in a large cohort of patients in Rome. METHODS: The records of 2682 patients discharged by the Emergency Department (ED) of the University Hospital of Tor Vergata, Rome, from January 2007 to November 2009 with the main diagnosis of reno-ureteric colic associated with a proven calculus, were retrospectively evaluated. The climatic parameters (average humidity, average air pressure and daily minimum, medium and maximum temperature) were recorded in a second, independent database. RC events were grouped by weeks and months and analysed for a total period of 35 months and 153 weeks. RESULTS: Two thousand five hundred and fourteen patients out of 2682 had a proven urolithiasis. RC events were observed more likely in the warmer months, from the second half of June to the first half of September, compared with the colder months. Although the weekly model showed a positive correlation (R2 = 0.134) between the average increase of environmental temperature and RC incidence, the monthly model was much more convincing (R2 = 0.373). We found no statistically significant correlation between humidity and air pressure and the incidence of RC. CONCLUSIONS: This study demonstrates that an increase in average environmental temperature is associated with a significant increase in the number of episodes of RC seen in the ED at both weekly and monthly time intervals. The average humidity and air pressure were not found to be associated with an increased incidence of RC.

Significance of focal proliferative atrophy lesions in prostate biopsy cores that test negative for prostate carcinoma.

OBJECTIVES: To evaluate the prevalence and short-term follow-up of focal proliferative atrophy lesions, either with or without the presence of inflammation (PIA/PA), and its correlation with the PSA levels, focusing on the prostate biopsy cores that test negative for prostate adenocarcinoma (PCa). METHODS: Five hundred fifty consecutive patients who had undergone a transrectal ultrasound-guided transperineal prostate biopsy were evaluated retrospectively for the presence and follow-up of focal proliferative atrophy lesions. PIA/PA were defined according to De Marzo. The prevalence of atrophy in PCa and negative biopsy cores was compared by means of χ(2). After logarithmic transformations of the PSA values, t-test and ANOVA were applied for the comparison of the means. Incidence of newly diagnosed PCa during follow-up (mean 33.7 months) in patients with or without focal proliferative atrophy was compared by means of χ(2). RESULTS: A focal atrophic lesion resulted in 161/339 negative biopsies. PIA was observed in 93/161 patients (57.8%), while PA was observed in the remaining 68/161 (42.2%). Among the negative biopsy cases, the difference in PSA values were not statistically significant according to the presence or absence of atrophy (P = 0.120). The group of negative biopsies with PIA was similar in terms of PSA characteristics with the benign (PA P = 0.738; non-atrophy P = 0.342), and cancer subgroups (P = 0.094); 245/339 (72.3%) patients were successfully followed-up. Biopsy was repeated in 24/71 (33.8%) patients with PIA, in 14/50 (28%) with PA and in 27/124 (21.7%) with no atrophy lesions at initial biopsy. The incidence of newly diagnosed PCa in the 3 groups was not statistically different (χ(2), P = 0.81). CONCLUSIONS: Focal proliferative atrophy lesions are a common finding in biopsy specimens negative for PCa. Patients with negative biopsy associated with PIA presented similar PSA characteristics as patients with biopsy-proven PCa. However, the incidence of PCa at short-term follow-up did not differ significantly between patients with PIA, PA, or no atrophic lesions at initial biopsy. Based on our findings, early repeat biopsy does not seem to be necessary after an initial diagnosis of PIA/PA, although a longer follow-up is mandatory for definitive conclusions.

Position: prone or supine is the issue of percutaneous nephrolithotomy.

INTRODUCTION: The prone position has been considered the only position for percutaneous access to the kidney for the past 25 years, whereas the supine Valdivia position has recently started to gain acceptance, although it was originally described in the late 1980s. Even more recently, the Galdakao-modified supine Valdivia position was described. However, there is no consensus on which is the best position for percutaneous nephrolithotomy, and the choice is currently based on the surgeon's preference. MATERIALS AND METHODS: The prone, supine, and modified supine positions are described, pointing out the advantages, disadvantages, and results of each technique. RESULTS: A number of potential advantages have been described for the supine over the prone position: less cardiovascular change; no need for patient repositioning (with less associated risk of central and peripheral nervous system injury); less X-ray exposure to the surgeon; and less risk of colonic injury. The recently described Galdakao-modified supine Valdivia position allows for a simultaneous anterograde and retrograde approach to the renal cavities for the one-stage treatment of complex renal stones or concurrent renal and ureteral calculi. Moreover, the use of a flexible ureteroscope allows for Endovision puncture to achieve perfect access to the kidney. CONCLUSIONS: The prone position still represents the standard for percutaneous access to the kidney, and other positions should be compared with this position. However, the supine and the modified supine positions have potentially important advantages for both patients and surgeons that need to be investigated in a large randomised trial to define their superiority over the traditional prone position.

Stones and urinary tract infections.

The term infection stones refers to calculi that occur following urinary tract infections (UTIs) caused by urease-producing gram-negative organisms. They consist of magnesium ammonium phosphate, carbonate apatite and monoammonium urate. Alkaline urine is most favorable to their formation. Urinary tract obstruction, neurogenic bladder, voiding dysfunction, temporary or indwelling urinary catheters, distal renal tubular acidosis and medullary sponge kidney are considered the main risk factors for developing infection stones. Urinalysis and urine culture are essential for diagnosis. A typical finding on imaging is a moderately radiopaque, staghorn or branched stone. Curative treatment is possible only by eliminating all of the stone fragments and by eradicating UTI. A variety of operative and pharmaceutical approaches is available. Metaphylactic treatment is mandatory to prevent recurrences. The relationship between urinary stones and UTIs is well known and shows two different clinical pictures: (1) stones that develop following UTIs (infection stones) which play a key role in stone pathogenesis, and (2) stones complicated by UTIs (stones with infection) which are metabolic stones that passively trap bacteria from coexistent UTIs and may consist of calcium or non-calcium. This article presents an overview of infection stones, analyzing the epidemiology, composition, pathogenesis, diagnosis, treatment and prevention of this type of calculi.

Acute lumbago and sciatica as first symptoms of focal xanthogranulomatous pyelonephritis.

Xanthogranulomatous pyelonephritis (XGP) is a rare inflammatory disease of the kidney, presenting in a diffuse or focal form. The preoperative diagnosis of XGP is made only in 10% of the cases because neither the clinical nor the radiological presentation are specific and could be confused with renal tumors, thus deserving the name of 'great imitator'. We report a case of focal XGP in a middle-aged man presenting with acute lumbago and sciatica, an unusual clinical presentation.