Enrique Pulido-Contreras

Objective: Fluoroscopy has been the most widely used guidance method for percutaneous nephrolithotomy (PCNL); however, radiation exposure is a significant concern. Recently, ultrasound has gained popularity, offering several advantages. The objective was to evaluate the safety and outcomes of the pure-ultrasound PCNL with a two-step tract dilation. Material and Methods: The authors retrospectively analyzed the data of patients from March 2019 to October 2023. In all patients, percutaneous renal access was ultrasound guided, and they were divided into 2 groups: Group 1, all steps of PCNL were performed under ultrasound guidance, and Group 2, tract dilation, confirmation of stone clearance, and exit strategy were done with fluoroscopy. Results: The authors included 100 patients, 60 in Group 1 and 40 in Group 2, with a mean body mass index of 30.8 kg/m2. Mean stone burden was 4,162 mm3, 53% were complex stones and 59% of the cases were without hydronephrosis in the targeted calyx. Fluoroscopy was absent in Group 1 and 20 (11.3-31.5) seconds in Group 2 (P < .001). Complications were present in 13% of the cases. Group 1 patients had a lower complication rate than those in Group 2 (10% and 17%, respectively, P = .27). The authors had a global stone-free rate of 79%, Group 1: 78.3% and Group 2: 80% (P = 1.0). Multivariate analysis revealed that the stone-free rate is associated with the total operative time (P = .002) and the number of tracts (P = .031). Conclusion: Pure ultrasound PCNL is a safe and effective technique, offering a similar stone-free rate compared to fluoroscopy and providing an alternative method to avoid radiation exposure during PCNL. Cite this article as: Pulido-Contreras E, Garcia-Padilla MA, Rios-Melgarejo C, Medrano-Sanchez J, Leon-Verdin MG, Sur RL. Pure ultrasound with two-step dilation vs. combined ultrasoundfluoroscopy in percutaneous nephrolithotomy: Is fluoroscopy still needed? Urol Res Pract. 2025;51(6):217-224.

Prostate cancer (PCa) is the most common neoplasm in men. Transrectal prostate biopsy is the standard for diagnosing PCa, but it presents complications. Transperineal biopsy has gained popularity due to its better detection rates and fewer complications. To compare the efficiency and complication rates between single-access point transperineal prostate biopsy (TPPB) and transrectal prostate biopsy (TRPB) in patients with suspected PCa. Information was collected and analyzed from 241 patients with suspected PCa, divided into 2 groups: 171 in the TPPB group and 70 in the TRPB group. Pathology results were collected and complications were identified. Out of the 241 patients, 132 had positive biopsies (54.77%) and 109 negative (45.22%). TPPB was positive in 60.2%, compared to 41.4% of TRPB (p = 0.008). Complications in TPPB were hematuria (53.8%), pain (6.4%), hemospermia (6.4%), and acute urinary retention (2.3%). TPPB shown to be a protective factor for complications (odds ratio [OR] 0.028, 95% confidence interval [95% CI] 0.009-0.9; p < 0.001), compared to the TRPB technique (OR 35.5, 95% CI 10.7-117.6; p < 0.001). TPPB offers a better detection rate for PCa and it should be adopted as the first-choice method for PCa diagnosis, given that it has a lower complication rate and can be performed without the need for bowel preparation or antibiotic prophylaxis.

Percutaneous nephrolithotomy (PCNL) is the treatment for large and complex renal stones. Fluoroscopic guidance is the most used imaging method; however, radiation exposure is a significant concern. Recent studies have shown that ultrasound-guided PCNL is also feasible. To evaluate the safety of the two-step tract dilation technique using ultrasound guidance to avoid radiation exposure. Retrospective evaluation of data of patients treated between February 2019 and January 2023. Two groups were included based on tract dilation: Group 1 (G1): two-step totally ultrasound-guided dilation, and group 2 (G2): fluoroscopy-guided dilation. 100 patients were included, 50 in each group. Body mass index (31.7 vs. 28.7kg/m²; p = 0.002) and stone burden (10,935.69 vs. 5,460.86mm³; p = 0.006) were higher in G1; fluoroscopy was absent in the same group (0 vs. 29.4 sec; p < 0.005). Complications occurred in 13 patients in G1 and in 7 in G2 (p = 0.32); no complications grade 3b, 4 or 5 were observed in either group. The overall stone-free rate was 76% (74% vs. 78%; p = 0.81). Ultrasound-guided PCNL is a safe technique that avoids radiation exposure without compromising clinical outcomes.

Priapism is a partial or total erection which lasts more than 4 hours that occurs in the absence of sexual stimulation. It has an incidence rate of 1.5 per 100,000 people. It is classified as ischemic (low-flow) or non-ischemic (high-flow). Non-ischemic priapism is an atypical presentation characterized by a non-rigid erection without pain, and it is frequently associated with trauma. Our objective is to present this clinical case to highlight the importance of correctly classifying priapism types to provide appropriate treatment and avoid complications. A 37-year-old male with no history of chronic degenerative diseases. Patient's condition began with a morning erection followed by sexual activity. Patient came to the Emergency Room 5 days later since the erection persisted, which he reported was pain-free. He denied recent trauma or the use of erectile stimulants. High-flow priapism was diagnosed via Doppler ultrasound. Selective angioembolization was performed, achieving an immediate detumescence of 40%. Corporal blood gas testing is essential in the initial evaluation of any patient presenting with priapism. For high-flow priapism, conservative management should first be attempted; if priapism persists, embolization of the affected pudendal artery can be offered.

Objective: The aim of this study was to develop and validate a low-cost and reproduc ible training model using gelatin that can be useful for acquiring the necessary skills for successful ultrasound-guided access in percutaneous nephrolithotomy without exposing patients to clinical risks. Methods: A prospective and analytical study involving 12 urology residents was con ducted to validate the model using content and construct validation systems. The study consisted of 2 parts: content validation through expert opinion surveys and construct validation through resident skill assessments before and after training on the model. This model imitates the calyx to puncture and was developed using pitted olives in dense gelatin. The model was constructed for a total cost of $29.7 per unit with an easy and reproducible construction. Each model can be used to perform approxi mately 40 punctures before the image quality deteriorates. Results: Globally, this training model increased skills. Puncture time decreased from 106 to 40.5 seconds after training (P = .002). The study found that the model was accepted by 71.4% of urologists as a safe training alternative and provided a risk-free environment for practicing the 2 skills required for a successful puncture: adjusting the ultrasound machine for an adequate image of the target and surrounding tissues and needle-probe alignment. Conclusion: This model is easy to build, reproducible, and cost-effective. It enhances the residents’ skills to increase success and safety when performing ultrasound-guided percutaneous access. Cite this article as: Pulido-Contreras E, Gonzalez-Villegas HO, Lopez-Hernandez JA, Medrano-Sanchez J, Garcia-Padilla MA. A low-cost gelatin-based model for ultrasound-guided percutaneous renal access. Urol Res Pract. 2025;51(2):54-60.

Introduction: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for kidney stones greater than 2 cm. ¹ This procedure in patients with obesity is challenging because obesity is a risk factor for complex access and requires more experience to achieve a successful puncture. ^{2 – 5} In this video, we demonstrate our technique for totally ultrasound-guided PCNL with two-step tract dilation, our experience, and provide guidance on improving success rates in patients with obesity. Materials and Methods: Surgical technique: With the patient in the supine position, we mobilized fatty tissue; after a proper ultrasound configuration, percutaneous access with a longitudinal freehand technique was obtained. Dilation with a two-step technique ⁶ Step 1: Creation of a minitract 14Fr to perform antegrade nephroscopy to check the renal cavities and measure the length of the tract; a pair of guides are placed in the ureter, one for definitive dilatation and the other as a safety guide. Step 2: Definitive tract 26Fr, insert the Amplatz dilator 1 cm in addition to the previously measured length of the tract to avoid a short dilation and advance the sheath. Pneumatic fragmentation is performed. Finally, a JJ stent was placed. Case series: Retrospective review of 54 patients treated with totally ultrasound-guided PCNL from July 2021 to June 2023, and we divided the cases according to their BMI: Group 1 included 27 patients with a BMI ≥30 kg/m2 and Group 2 included 27 patients with a normal BMI. Results: Mean age was 46.9 years. The BMI was 36.3 kg/m ² (±5.9) and 21.7 kg/m ² (±2.4) ( p = 3 (±11,287.6) and 7,543.0 mm ³ (±10,203.6) ( p = 0.056), with a mean of 12 cm and 8 cm of tract length ( p < 0.001), respectively ( Table 1 ). In the obesity group, the short dilation was more frequent, 63% vs. 26% ( p = 0.013). The stone-free rate was 77.8% in both groups ( p = 1.000), and we found that the stone burden had a more significant effect on the stone-free rate than the BMI ( Fig. 1 ). In Group 1, the complications were 3 (11.1%); 2 patients had fever (Clavien I), and 1 needed a blood transfusion due to anemia (Clavien II), whereas in Group 2 there were 6 (22.2%); 4 had fever (Clavien I), and 2 had urosepsis (Clavien IV) ( p = 0.019). FIG. 1. Relation between stone volume (mm ³ ) and body mass index (Kg/m ² ) in stone-free status: In blue , the patients with stone-free status, and in red , the patients with residual stone. Table 1. Preoperative and Postoperative Descriptive Data by Group according to BMI Total Group 1: BMI (≥30 kg/m ² ) Group 2: BMI (≤25 kg/m ² ) p Value Number of patients 54 27 27 Age, years 48.4 (±11.9) 49.9 (±11.1) 46.9 (±12.7) 0.36 Gender: n (%) Male 18 (33.3) 9 (33.3) 9 (33.3) 0.613 Female 36 (66.7) 18 (66.7) 18 (66.7) BMI (kg/m ² ) 29.06 (±27.7) 36.3 (±5.9) 21.7 (±2.4) n (%) None 34 (62.9) 18 (66.7) 16 (59.3) 0.976 SWL 2 (3.7) 1 (3.7) 1 (3.7) Ureteral Stent 10 (18.5) 5 (18.5) 5 (18.5) Flexible Ureteroscopy 2 (3.7) 1 (3.7) 1 (3.7) PCNL 5 (9.2) 2 (7.4) 3 (11.1) Open Surgery 1 (1.8) 0 1 (3.7) Guy Stone: n (%) Guy 1 11 (20.3) 4 (14.8) 7 (25.9) 0.047 Guy 2 11 (20.3) 4 (14.8) 7 (25.9) Guy 3 20 (37) 15 (56.6) 5 (18.5) Guy 4 12 (22.2) 4 (14.8) 8 (29.6) Skin-stone distance (cm) 9.8 (±2.5) 11.7 (±2.0) 8.0 (±1.1) 3 ) 9259.75 (±10797.2) 10976.43 (±11287.6) 7543.0 (±10203.6) 0.056 Hydronephrosis, n (%) None 34 (62.9) 19 (70.4) 15 (55.5) 0.494 Mild 10 (18.5) 3 (11.1) 7 (25.9) Moderate 10 (18.5) 5 (18.5) 5 (18.5) Tract number: n (%) One tract: 26Fr 44 (81.4) 22 (81.5) 22 (81.5) 1.000 Two tracts: 26Fr 9 (16.6) 5 (18.5) 4 (14.8) Three tracts: 26Fr 1 (1.85) 0 (0) 1 (3.7) Tract loss, n (%) Yes 4 (7.4) 2 (7.4) 2 (7.4) 1.000 No 50 (92.6) 25 (92.6) 25 (92.6) Short dilation, n (%) Yes 24 (44.4) 17 (63) 7 (25.9) 0.013 No 30 (55.4) 10 (37) 20 (74.1) Complications, Clavien– Dindo, n (%) Grade 1 6 (11.1) 2 (7.4) 4 (14.8) 0.019 Grade 2 1 (1.8) 1 (3.7) 0 Grade 3 0 0 0 Grade 4 2 (3.7) 0 2 (7.4) Hemoglobin drop (g/dL) 1.57 (±1.63) 1.62 (±1.71) 1.52 (±1.57) 0.986 Operative time (min) 137.4 (±60.7) 141.6 (±54.6) 133.1 (±67.0) 0.314 Stone free status, n (%) 42 (77.8) 21 (77.8) 21 (77.8) 1.000 p Value of t tests to compare means and Fisher’s exact test p value. Conclusion: A proper ultrasound configuration and adipose tissue mobilization increase success in obese patients. This technique offers a good stone-free rate and a safety profile without radiation. Rutime of video: 7 min 25 sec. No competing financial interests exist. Informed consent was obtained to film portions of the procedure from the patient who appeared in this video.

Introduction: The mini-perc technique was developed in 1997 to reduce trauma during percutaneous nephrolithotomy (PCNL) in children. ¹ The first ultrasound-guided mini-perc was performed in 1999 by Desai et al. ² Super mini PCNL (SMP) developed by Zeng et al. improves the mini-perc by using an irrigation–suction sheath that allows continuous suction of fragments and prevents excessive intrarenal pressure, improving observation and extraction of the stone. ³ Ultrasound-guided SMP has demonstrated a safe and effective treatment with the advantage of avoiding radiation. ⁴ Li et al. described the two-step dilation in standard ultrasound-guided PCNL ⁵ ; in this video, we describe the advantages of this technique in improving safety in SMP totally ultrasound-guided. Materials and Methods: Between July 2022 and July 2023, 15 patients underwent totally ultrasound-guided SMP with a two-step tract dilation. Surgical technique: In the Galdakao-modified Valdivia position, previous placement of a ureteral occlusion catheter, we adjusted the ultrasound parameters: gain, focus, depth, and dynamic range, and used an echogenic needle. ⁶ The access was obtained with a longitudinal freehand technique, obtaining urine indicates a successful puncture, an extra stiff guide was passed and sequential dilation (Step 1) with 10F to 12F to 14F fascial dilators; as it advances into the collector system, the dilator hides the guide and a plastic 14F peel-away sheath is placed (The plastic sheath does not create artifacts when observed with ultrasound, unlike metal sheaths, allowing better and safer control of dilation). An antegrade nephroscopy is performed to check the renal cavities and measure the length of the tract, and a pair of guides are placed in the ureter, one for definitive dilatation and the other as a safety guide. (Step 2): Placement of definitive metallic 14F irrigation–suction sheath (Hawk) under ultrasound control; insert 1 cm in addition to the previously measured length of the plastic sheath to avoid a short dilation; lithotripsy was performed with a 40 W holmium laser using fragmentation settings. The safety guidewire remains outside of the definitive sheath, and this enhances safety and prevents tract loss if the sheath is accidentally removed. Results: Dilation problems such as short dilation, tract loss, and collecting system injury were not encountered in any patient. The average age was 44 years, with a BMI of 28.3 ± 4.5 kg/m ² , with a predominance of left kidney stones in 53% of cases. The average stone burden was 2263 ± 1213 mm ³ (837 HU) the most frequent location was in the lower calix (46%). The mean operative time was 79 minutes (80–120). The lower calix was punctured in 53% with an average puncture time of 51 seconds. Because of the hypermobility of the lower pole, we migrated to routinely access the middle calyx. A single tract in 93% of cases, obtaining 93% stone free and totally tubeless in all cases. 80% of the procedures were ambulatory. The mean hemoglobin loss was 1.14 g/dL; only three patients had fever (Clavien I), and no other complications were recorded. Conclusions: This dilation technique appears to increase the safety of the procedure. SMP allows a good stone-free rate and can be an ambulatory and totally tubeless surgery. The study adhered to institutional review board protocols. Surgical videos were recorded with patient consent during routine care. Consent for video recording and publication of procedure was obtained and archived before the recording. No competing financial interests exist. Runtime of video: 8 mins 32 secs

Objective To assess safety, urinary symptoms, and feasibility of JJ stent removal with exteriorized threads through the percutaneous tract after percutaneous nephrolithotomy (PCNL). Materials and methods Prospective, transversal, comparative, experimental, randomized 1-to-1 cohort study in 52 patients who underwent “tubeless” PCNL from October 2020 to November 2022. Group A with threads through the urethra and Group B through the percutaneous tract. The validated USSQ (Ureteral Stent Symptom Questionnaire) was applied in the Urology office a week after the procedure, and the JJ stent was withdrawn by pulling the threads. Hemoglobin and urine culture, and pre- and post-surgery were evaluated. Results There is a statistically significant difference in favor of group B when comparing urinary symptoms (p = 0.008), body pain (p = 0.009), and general condition (p = 0.042), mainly for non-urgency incontinence, frequency of analgesic use, and dysuria. There were significant differences between groups (p = 0.028, p = 0.026, p = 0.027, respectively). There is no association with urinary infections (p = 0.603) nor an increased risk of bleeding (p = 0.321). Conclusion The removal of the JJ stent with exteriorized threads through the percutaneous tract after PCNL in the office is a feasible and safe procedure if it is removed before 8 days and has better tolerance regarding the urinary symptoms.

Purpose The ultrasound-guided (US) puncture in percutaneous nephrolithotomy (PCNL) has demonstrated advantages over traditional fluoroscopy access. The aim of this study was to demonstrate the reduction of fluoroscopy time using this technique during PCNL as the surgeon gained experience. Methods Transversal study performed on 30 consecutive patients undergoing PCNL from March to November 2019. All punctures were performed with US guidance. The patients were divided into 2 groups of 15 each according to the chronological order of the intervention. Demographic data, preoperative parameters, puncture time, fluoroscopy time, stone-free rate and complications were analyzed. Results The time of fluoroscopy was considerably reduced as the experience in the number of cases increased, reducing from 83.09 ± 47.8 s in group 1 to 22.8 ± 10.3 s in group 2 (p < 0.01), the time required to perform the puncture was reduced of 108.1 ± 68.9 s in group 1, to 92.6 ± 94.7 s in group 2 (p < 0.67). Stone free rate of 83.3% was obtained globally. Conclusion US percutaneous renal access is safe and reproducible technique; the main advantage is to reduce exposure to radiation without compromising clinical results and has a short learning curve for urologists with prior experience in PCNL.

Clinical case description: A 48-year-old man had a history of giant platelet disorder and diagnosis of horseshoe kidney with kidney stones. Standard 24 Fr percutaneous nephrolithotomy was performed. Ten days after surgery, the patient presented with clot-forming gross hematuria, resulting in anemia. Arteriovenous fistula was suspected and evaluation at the interventional cardiology service was ordered. Arteriovenous fistula diagnosis was confirmed and superselective embolization was performed in the anterior and posterior segmental artery, with complete resolution of the hematuria. Relevance: To present the uncommon, post-percutaneous nephrolithotomy complication of hematuria secondary to arteriovenous fistula that was resolved through a minimally invasive technique in a patient with a kidney fusion anomaly. Clinical implications: To take measures in that patient group to reduce what can be a life-threatening complication, managing it through superselective embolization to prevent kidney function deterioration. Conclusions: Color Doppler ultrasound-guided percutaneous access aids in the prevention of injury to the renal vasculature during puncture and the use of miniaturized tracts can reduce the development of segmental artery lesion that could later condition fistula formation. Embolization is safe and effective in that group of patients.