A new surgical technique for sutureless partial nephrectomy: renal sutureless device.

BACKGROUND: Several factors impact the preservation of renal function after partial nephrectomy. Warm ischemia time is the main modifiable surgical factor. Renorrhaphy represents the key of hemostasia, but it is associated with increase of warm ischemia time and complications. The aim of this study was to describe our initial surgical experience with a new surgical technique for sutureless partial nephrectomy, based on the application of our own developed renal-sutureless-device-RSD. METHODS: Between 2020-2021, 10 patients diagnosed with renal cell carcinoma stage cT1a-b cN0M0 with an exophytic component were operated using renal-sutureless-device-RSD. Surgical technique of sutureless partial nephrectomy with renal-sutureless-device-RSD is described in a step-by-step fashion. Clinical data was collected in a dedicated database. Presurgical, intraoperative, postoperative variables, pathology and functional results were evaluated. Medians and ranges of values for selected variables were reported as descriptive statistics. RESULTS: Partial nephrectomy was carried out with the use of renal-sutureless-device-RSD without renorrhaphy in all cases (70%cT1a-30%cT1b). Median tumor size was 3.15 cm (IQR: 2.5-4.5). R.E.N.A.L Score had a range between 4a-10. Median surgical time was 97.5 minutes (IQR 75-105). Renal artery clamping was only required in 4 cases, with a median warm ischemia time of 12.5 minutes (IQR 10-15). No blood transfusion, intraoperative and postoperative complications were noted. Free-of-disease margin rate achieved was 90%. Median length of stay was 2 days (IQR 2-2). Laboratory data on hemoglobin and hematocrit levels, as well as renal function tests, remained stable after partial nephrectomy. CONCLUSIONS: Our initial experience suggests that a sutureless PN using the RSD device is feasible and safe. Further investigation is needed to determine the clinical benefit of this technique.

Does Time and Size Matter in Retrograde Intrarenal Surgery? Results Analysis Using a Low-Pressure Technique

Purpose: Kidney stone disease affects 5% of the population and is associated with non-negligible morbidity. Retrograde intrarenal surgery and percutaneous nephrolithotomy are the treatments of choice. We analyzed the results from our patients who underwent retrograde intrarenal surgery at controlled pressure. Materials and Methods: We conducted an observational, descriptive, retrospective study of 403 patients who underwent retrograde intrarenal surgery at the Hospital Clínico Universitario Lozano Blesa (Zaragoza, Spain) between January 2013 and December 2019. Results: The mean surgical time was 111.1 minutes, with a mean stone volume of 3.5 cm3 (maximum volume, 38.3 cm3). A total of 70 patients (17.3%) developed postoperative Clavien-Dindo complications—64 minor (91.4%) and 6 major (8.6%). In addition, 28 patients (6.9%) presented with an early complication (<3 months), with urinary tract infection and pyelonephritis being the most common. The stone-free rate was 69.0%, with a retreatment rate of 4.7%. Conclusions: Sex was statistically significantly related to the onset of minor Clavien postoperative complications (p = 0.001). Similarly, corticosteroid use was associated with the onset of major Clavien complications (p = 0.030). Neither surgical time nor stone volume was found to be statistically significantly related to the onset of Clavien postoperative complications or early complications (AU)

Minimally Invasive Laparoscopic Technique for Lymph Node Dissection in Penile Cancer: The Pelvic and Inguinal Single-Site Approach: PISA Technique.

BACKGROUND: Lymph node dissection(LND) remains the gold standard in the staging and treatment of locally advanced penile cancer(PC)1. OBJECTIVE: To describe our initial experience with a new minimally invasive inguinal and pelvic single-access laparoscopic approach2,for performing LND in PC, first described in Urology by our group in 20153: the Pelvic and Inguinal Single Access(PISA) technique (Fig. 1). MATERIAL: Between 2015 and 2018, 10 consecutive patients with different PC stages and indication of inguinal LND (cN0 and ≥pT1G3 or cN1/cN2)1 were operated by means of the PISA technique (Table 1). Intraoperative frozen section(FS)4 analysis was carried out routinely and if ≥2 inguinal nodes(pN2) or extracapsular nodal extension(pN3) are detected1,5, ipsilateral pelvic LND was performed sequentially as a single-stage procedure and using the same surgical incisions. If this condition occurs bilaterally in the inguinal LND, the pelvic LND will be bilateral. The video shows the PISA technique in a step-by-step. Instrumental requirements: 30°laparoscopy optic, monopolar scissors,Ligasure (Covidien Surgical,Minneapolis,MN,USA) vascular sealant, extraction-bag, bipolar forceps and 5-mm endo-clip(Hem-o-lok)are required. RESULTS: Intraoperative and postsurgical variables are shown in Table 2. Inguinal LND was bilateral in all cases. Pelvic LND was required in 40% of patients. Total operative time was 120-170 minutes. Median estimated blood loss(EBL) was 66(30-100)cc, but no blood transfusion was required. No intraoperative complications were noted. 40% of patients had postoperative complications (10% major complication- symptomatic inguinal lymphocele). Median lenght of hospital stay(LOS)was 5.8(3-10) days. Median inguinal drain removal was 4.7 days. The pathological analysis outcomes are shown in Table 3. Mean number of lymph nodes removed by inguinal LND was 10.25(8-14). CONCLUSION: PISA technique allow a minimally invasive inguinal and pelvic LND using the same set of incisions and carry it out in the same surgical procedure. PISA technique in PC LND seems to be safe, with a low rate of major complications and preserving oncological efficacy.

The usefulness of densitometry in predicting the composition and fragility of urolithiasis.

INTRODUCTION: The choice of ideal treatment for a given lithiasis is a crucial factor for its success, minimizing the number of interventions and complications. Previous determination of stone composition and its fragility is desirable, to predict its behavior during extracorporeal shock wave lithotripsy and for evaluation of its appropriateness, or to set the indication for other techniques. OBJETIVES: To determine the role of densitometry in the prediction of composition and fragility of urinary lithiasis undergoing SWL. METHODS: Experimental prospective, blinded, in vitro study using 193 urinary calculi of known composition : monohydrated calcium oxalate, mixed calcium oxalate, uric acid, and calcium carbonate, obtained from spontaneous passage or surgery. Densitometry and SWL were performed on them. We compare the mineral composition of the stone and mineral density of each composition group to check if they are characteristic of each type and correlate these parameters with the energy dose required to fragment them down to a given fragment size. RESULTS: Only 53 out of 193 stones showed valuable data. Calcium carbonate was the composition showing grater mineral content and density (1,24 gr and 0,47 gr/cm2), followed by mixed oxalate (0,51/0,26) and uric acid (0,52/ 0,15), finishing with the monohydrate calcium oxalate group (0,32/0,05).Only the comparison between calcium carbonate and monohydrated calcium oxalate showed statistically significant results (p<0,05). Correlation coefficients between mineral content (0,347) and density (0,424) and the energy used for stone fragmentation to a given fragment size were statistically significant (p<0,05) CONCLUSIONS: In our study, the use of densitometry to determine stone composition and lithiasic fragility did not show conclusive results due to the limited number of calculi tested. Nevertheless, there are signs that, with a different study design , more practically useful results could be achieved.

Utilidad de la densitometría en la predicción de la composición y fragilidad litiásica / The usefulness of densitometry in predicting the composition and fragility of urolithiasis

INTRODUCCIÓN: La elección del tipo de tratamiento ideal para una determinada litiasis es un factor crucial para el éxito del mismo, minimizando el número de intervenciones y complicaciones. Es deseable la determinación a priori de la composición de la litiasis y de su fragilidad, para predecir su comportamiento durante el tratamiento con litotricia extracorpórea (LEOC) y valorar la idoneidad de este, o si se deben emplear otras técnicas. OBJETIVO: Determinar el papel de la densitometría en la predicción de la composición y fragilidad de litiasis que van a ser tratadas con LEOC.MÉTODOS: Estudio experimental, in vitro, prospectivo, y ciego, realizado empleando 193 cálculos urinarios de composición conocida: oxalato cálcico monohidrato (OCM), oxalato cálcico mixtos, ácido úrico y carbonato de apatita, obtenidos mediante expulsión espontánea o cirugía. Éstos son sometidos a densitometría y litotricia extracorpórea. Comparamos el contenido mineral de la litiasis y la densidad mineral de la litiasis de cada grupo de composición para comprobar si son características propias de cada tipo, y correlacionamos estos parámetros con la dosis de energía necesaria para la fragmentación hasta una conminución definida. RESULTADOS: Sólo 53 de los 193 cálculos arrojaron datos que pudiesen ser valorados. Carbonato de apatita ha sido la composición que ha mostrado un mayor contenido y densidad mineral (1,24 gr y 0,47 gr/cm2), seguido de los mixtos de oxalato (0,51/0,26) y úrico (0,52/ 0,15), finalizando con el grupo OCM (0,32/0,05). Sólo la comparación carboapatita-OCM mostró resultados estadísticamente significativos (p<0,05). Los coeficientes de correlación entre contenido (0,347) y densidad mineral (0,424) y la energía empleada para la fragmentación litiásica hasta la conminución definida presentaron significación estadística (p<0,05). CONCLUSIONES: En nuestro estudio el empleo de la densitometría para determinar la composición y fragilidad litiásica no ha mostrado resultados concluyentes dada la escasez de cálculos detectados. Se aprecian no obstante indicios de que, con un diseño diferente, podrían conseguirse resultados de mayor utilidad práctica

INTRODUCTION: The choice of ideal treatment for a given lithiasis is a crucial factor for its success, minimizing the number of interventions and complications. Previous determination of stone composition and its fragility is desirable, to predict its behavior during extracorporeal shock wave lithotripsy and for evaluation of its appropriateness, or to set the indication for other techniques. OBJETIVES: To determine the role of densitometry in the prediction of composition and fragility of urinary lithiasis undergoing SWL. METHODS: Experimental prospective, blinded, in vitro study using 193 urinary calculi of known composition: monohydrated calcium oxalate, mixed calcium oxalate, uric acid, and calcium carbonate, obtained from spontaneous passage or surgery. Densitometry and SWL were performed on them. We compare the mineral composition of the stone and mineral density of each composition group to check if they are characteristic of each type and correlate these parameters with the energy dose required to fragment them down to a given fragment size. RESULTS: Only 53 out of 193 stones showed valuable data. Calcium carbonate was the composition showing grater mineral content and density (1,24 gr and 0,47 gr/cm2), followed by mixed oxalate (0,51/0,26) and uric acid ((0,52/ 0,15), finishing with the monohydrate calcium oxalate group (0,32/0,05). Only the comparison between calcium carbonate and monohydrated calcium oxalate showed statistically significant results (p<0,05). Correlation coefficients between mineral content (0,347) and density (0,424) and the energy used for stone fragmentation to a given fragment size were statistically significant (p<0,05). CONCLUSIONS: In our study, the use of densitometry to determine stone composition and lithiasic fragility did not show conclusive results due to the limited number of calculi tested. Nevertheless, there are signs that, with a different study design, more practically useful results could be achieved

Bladder cancer in Spain 2011: population based study.

PURPOSE: We estimate the annual incidence of bladder cancer in Spain and describe the clinical profile of patients with bladder cancer enrolled in a population based study. MATERIALS AND METHODS: Using the structure of the Spanish National Health System as a basis, in 2011 the AEU (Spanish Association of Urology) conducted this study with a representative sample from 26 public hospitals and a reference population of 10,146,534 inhabitants, comprising 21.5% of the Spanish population. RESULTS: A total of 4,285 episodes of bladder cancer were diagnosed, of which 2,476 (57.8%) were new cases and 1,809 (42.2%) were cases of recurrence, representing an estimated 11,539 new diagnoses annually in Spain. The incidence of bladder cancer in Spain, age adjusted to the standard European population, was 20.08 cases per 100,000 inhabitants (95% CI 13.9, 26.3). Of patients diagnosed with a first episode of bladder cancer 84.3% were male, generally older than 59 years (81.7%) with a mean ± SD age of 70.5 ± 11.4 years. Of these patients 87.5% presented with some type of clinical symptom, with macroscopic hematuria (90.8%) being the most commonly detected. The majority of primary tumors were nonmuscle invasive (76.7%) but included a high proportion of high grade tumors (43.7%). According to the ISUP (International Society of Urologic Pathology)/WHO (2004) classification 51.1% was papillary high grade carcinoma. Carcinoma in situ was found in 2.2% of primary and 5.8% of recurrent cases. CONCLUSIONS: The incidence of bladder cancer in Spain, age adjusted to the standard European population, confirms that Spain has one of the highest incidences in Europe. Most primary nonmuscle invasive bladder cancer corresponded to high risk patients but with a low detected incidence of carcinoma in situ.

Lithiasis size estimation variability depending on image technical methodology.

UNLABELLED: The lithiasic size is a determining factor in selecting the most suitable treatment, surgical or medical. However, the method for obtaining a reliable lithiasic size is not standardized. Our objetives are to determine the differences between the estimated lithiasic sizes shown by plain radiography test and by computerized axial tomography (CT) scan (using different techniques) in relation to the actual size, and to establish which is the ideal type of imaging for this purpose. We present an in vitro model with lithiasis obtained in cooperation with four centers. INCLUSION CRITERIA: lithiasis >0.5 cm, intact, and visible via simple radiography. A sample of 245 lithiases was obtained, with 87 rejected as they did not fulfill the inclusion criteria. Initially the three main actual diameters of each lithiasis were measured with a calibrator, then a plain X-ray and a CT scan were taken of the samples to determine the surface size in cm(2) for simple radiography; surface size and volume in cm(3) for CT scan, in bone window and soft tissue (Toshiba Aquillion 64, sections of 0.5 mm, 120 Kv, 250 mA). The tomographic area was calculated by employing the formula recommended by the European Association of Urology and scanner software. The actual, radiographic and tomographic measurements were taken by three different researchers who were unaware of the results obtained by the each other. The statistics program IBM SPSS Statistics(®) 19 was used. Differences were analyzed using the Wilcoxon sign test. The bone window CT scan slightly overestimated the actual lithiasic size (0.12 vs. 0.17 cm(3)), while in soft tissue window the actual volume was practically doubled (0.12 vs. 0.21 cm(3)) (p < 0.05). We did not find statistically significant differences in the comparison between actual surface size (0.39 cm(2)) and bone window CT scan size when using the EAU formula or scanner software (0.36/0.37 cm(2)). Resulting measurements in soft tissue window tended to significantly overestimate the surface size, although only slightly (0.42/0.44 cm(2)), whilst the plain radiography underestimated it slightly but significantly (0.37 cm(2)). CT scan, using the bone window, is the technical methodology with which the greatest in vitro accuracy in which actual lithiasis measurements can be estimated, although the craniocaudal diameter measurement will be overestimated. Using soft tissue window gives an overestimated size.

[Multilocular cystic nephroma. Report of three new cases]. / Nefroma quístico multilocular. Aportación de 3 nuevos casos.

OBJECTIVE: To analyze the presentation of multilocular cystic nephroma and its diagnostic-therapy scheme. METHODS: We report the three last new cases presenting in our department in a period of three years. RESULTS: Multilocular cystic nephroma is a benign lesion, rare that appears both in adult age, generally asymptomatic, and in children, frequently as a palpable mass. Differential diagnosis with malignant tumours is required. CONCLUSIONS: The great variety of clinical presentations, differential diagnosis and places of origin of the cases is demonstrated, being this a reflection of our daily medical practice, in which we cannot reach definitive diagnosis with imaging tests, being the Bosniak's classification very useful for the setting of indication for surgery, which will give definitive diagnosis of multilocular cystic nephroma or what is more important will rule out malignancy.

Nefroma quístico multilocular aportación de 3 nuevos casos / Multilocular cystic nephroma. Report or three new cases

OBJETIVO: Analizar la forma con la cual se nos presenta el nefroma quístico multilocular y el enfoque diagnóstico- terapéutico que debemos realizar.MÉTODOS: Aportamos los 3 últimos nuevos casos que se nos han presentado en nuestro servicio en un periodo de 3 años.RESULTADO: El nefroma quístico multilocular es una lesión benigna, poco frecuente apareciendo en edad adulta, habitualmente de forma asintomática, y en edad infantil frecuentemente como masa palpable. Requiere realizar diagnostico diferencial con tumoraciones malignas.CONCLUSIONES: Se demuestra la gran variedad de presentaciones clínicas, diagnósticos diferenciales y lugares de procedencia de los casos, siendo esto un reflejo de nuestra practica médica diaria sin poder llegar al diagnostico definitivo mediante pruebas de imagen, siendo muy útil la aplicación de la clasificación de Bosniak para indicar la intervención quirúrgica que nos dará el diagnostico definitivo de nefroma quístico multilocular o lo que es más importante, nos descartará proceso maligno(AU)

OBJECTIVE: To analyze the presentation of multilocular cystic nephroma and its diagnostic-therapy scheme.METHODS: We report the three last new cases presenting in our department in a period of three years.RESULTS: Multilocular cystic nephroma is a benign lesion, rare that appears both in adult age, generally asymptomatic, and in children, frequently as a palpable mass. Differential diagnosis with malignant tumours is required.CONCLUSIONS: The great variety of clinical presentations, differential diagnosis and places of origin of the cases is demonstrated, being this a reflection of our daily medical practice, in which we cannot reach definitive diagnosis with imaging tests, being the Bosniak’s classification very useful for the setting of indication for surgery, which will give definitive diagnosis of multilocular cystic nephroma or what is more important will rule out malignancy(AU)

Aplicación del láser en la nefrolitotomía percutánea / The use of laser for percutaneous nephrolithotomy

Objetivo: El índice no despreciable de cálculos residuales tras la litotricia extracorpórea está haciendo replantear las indicaciones de la nefrolitotomía percutánea (NLP). El láser, de la mano de los nefroscopios flexibles, juega un gran papel en este terreno. Los láseres de Nd-YÁG pulsado, el de colorante y el de Álexandrita han dado paso al láser de holmium YÁG en el tratamiento endourológico de la litiasis urinaria. Métodos: En las nefrolitotomías percutáneas de cálculos de gran volumen suele requerirse de más de un tipo de litotritor, y geralmente se prefieren por su alto rendimiento los litotritores balísticos o electrokinéticos. El láser de holmium encuentra sus mejores indicaciones en el tratamiento de los cálculos caliciales alejados de la pelvis y sólo accesibles a través de un nefroscopio flexible. También son buenas indicaciones para el mismo las «midi y mini percs», la litiasis renal en la infancia y algunos cálculos terrosos, de poca consistencia. Según las características anatómicas del riñón y de localización, número, tamaño y dureza del cálculo pueden utilizarse fibras de 200, 365 ó 500 mm. Debido a que el láser horada al cálculo como si se tratara de una barrena térmica, éste puede romperse de varias maneras: aplicando la fibra de cuarzo entre sus capas, horadando todo su interior antes de fragmentar su superficie o taladrarlo en múltiples puntos para debilitarlo y crear amplias líneas de fractura. Para acelerar la rotura puede optarse por utilizar fibras más gruesas o por modificar la programación de datos del equipo incrementando su potencia, si bien esto conlleva un potencial riesgo para el riñón. Resultados: El teórico 100% de buenos resultados se ve reducido por la interferencia de múltiples factores técnicos y anatómicos: tamaño, número, situación y dureza del cálculo, así como por las posibilidades de alcanzar a ver el cálculo y poder confrontar el extremo de la fibra contra el mismo. Conclusiones: Aunque el láser de holmium presta un magnífico papel a la hora de evitar o reducir el número de cálculos residuales, en ocasiones su eficacia se ve superada por la de la litotricia electrohidráulica (AU)

Objectives: The non negligible number of residual stones after extracorporeal lithotripsy is leading to a revision of the indications of percutaneous nephrolithotomy (PCNL). The laser, managed with flexible nephroscopes, plays an important role in this field. Pulsed Nd: YAG, dye and alexandrite lasers have given way to the holmium:yag laser in the endourological treatment of urinary lithiasis. Methods: More than one lithotripter are often required for percutaneous nephrolithotomy of great volume stones, and ballistic and electrokinetic lithotripters are generally preferred due to their high performance. The best indications for Holmium laser is the treatment of caliceal stones far from the pelvis, only accessible through flexible nephroscopes. Midi and minipercs, renal lithiasis in children and some earthy calculi, of low consistency, are also good indications for it. Depending on the anatomical characteristics of the kidney and localization, number, size and hardness of the stone 200,365, or 500 nanometer fibers may be employed. Due to the fact that the laser drills a hole in the stone like if it is a thermal barrier, it may break in different ways: applying the quartz fiber in between the layers, drilling all the interior before breaking the surface, or drilling multiple points to weaken it and creating broad fracture lines. To accelerate the breaking process one can choose to use larger fibers or to modify the settings of the equipment increasing the potency, although this has some potential risk for the kidney. Results: The theoretical 100% of good results is reduced due to multiple technical and anatomical factors: size, number, localization, and hardness of the stone, as well as the possibility of reaching and seeing the calculus and being able to place the tip of the fiber against it. Conclusions: Although the holmium laser develops an excellent role at the time of avoiding leaving residual calculi or diminishing the number of them, sometimes the electrohydraulic lithotripsy is more effective (AU)

Cirugía mínimamente invasiva en urología pediátrica dentro de un servicio de urología general / Minimally invasive surgery in pediatric patients within a general urology department

Objetivo: Los avances en cirugía minimamente invasiva en urología en los últimos años han permitido la paulatina y constante introducción de la endourología y laparoscopia en pacientes pediátricos. Realizamos una revisión de nuestra experiencia, como hospital general, de la cirugía minimamente invasiva realizada en los últimos 10 años en pacientes pediátricos. Métodos: Se analizan retrospectivamente las intervenciones en el ámbito de la endourología y laparoscopia realizadas durante el periodo entre 1997 y 2007 en niños de hasta 16 años, recogiendo datos sobre la edad y sexo de los pacientes, tipo de patologías, técnicas empleadas, anestesia realizada e incidencias perioperatorias. Resultados: Se realizaron 72 intervenciones quirúrgicas en pacientes con un rango de edad entre 28 días y 16 años y una media de 6,8 años. El 56% son varones y el 44% niñas. 28 intervenciones por Reflujo Vesico Renal (RVRj (38,8º%), 17 intervenciones por patología litiásica (23,6%) de las cuales 4 fueron cistolitotricias, 9 uretero-rrenolitotricia, 1 nefrolitectomía percutánea (NLP) pura y 3 mixtas. 9 intervenciones sobre ureteroceles (12,5%), 7 por obstrucciones uretrales (9,7%), 3 criptorquidias diagnósticas laparoscópicas (4,1 %), 2 intervenciones mediante laparoscopia por patología quistita (2,7%) y otras 2 laparoscopias para realización de biopsia renal (2,7%) y un síndrome de la unión pieloureteral intervenido mediante laparoscopia. Un caso de nefrostomía percutánea en decúbito supino de urgencia tras pieloplastia abierta con posterior intervención mediante resección percutáneo de granuloma. Un caso de inyección de toxina botulínica en detrusor. Conclusiones: La consolidación en nuestro servicio de la endourología, y mas recientemente la laparoscopia infantil, contribuyendo a mejorar la calidad asistencial en el paciente pediátrico lográndose gracias a un conocimiento previo en técnicas endourológicas generales y de unos medios técnicos y humanos adecuados (AU)

Objectives: The advances of minimally invasive surgery in urology over the last years have enabled a progressive and constant implementation of endourology and laparoscopy in pediatric patients. We perform a review of our experience, as a general hospital, with minimally invasive surgery performed in pediatric patients over the last ten years. Methods: We retrospectively analyzed the endourological and laparoscopic operations performed between 1997 and 2007 in children up to the age of 16 years, collecting data about patient's age and gender, type of disease, techniques, anesthesia, and perioperative events. Results: seventy-two surgical operations were performed in patients with an age range between 28 days and 16 years, with a mean age of 6.8 years. 56% of the patients were boys and 44% girls. Indications for surgery was vesicoureteral reflux (VUR) in 28 cases (38.8%); lithiasis 17 cases (23.6%) which were distributed in 4 cystolithotripsies, 9 ureterorenoscopy with lithotripsy, one pure percutaneous nephrolithotomy and three mixed; ureterocele 9 cases (12.5%); urethral obstruction 7 cases (9.7%); 3 diagnostic laparoscopies for cryptorchidism (4.1%), 2 laparoscopic procedures for cystic pathology (2.7%), another 2 laparoscopic renal biopsies (2.7%), and one laparoscopic repair of a ureteropyelic junction syndrome; 1 case of emergency percutaneous nephrostomy in the supine position after open pyeloplasty with subsequent reoperation with percutaneous resection of a granuloma; and 1 case of botulin toxin injection into the detrusor muscle. Conclusions: The consolidation of pediatric endourology in our department, and more recently laparoscopy, has contributed to improve the quality of care in pediatric patients; it has been achieved thanks to our previous know-how in general endourological techniques and the existence of adequate technical and human resources (AU)

[The use of laser for percutaneous nephrolithotomy]. / Aplicación del láser en nefrolitotomía percutánea.

OBJECTIVES: The non negligible number of residual stones after extracorporeal lithotripsy is leading to a revision of the indications of percutaneous nephrolithotomy (PCNL). The laser, managed with flexible nephroscopes, plays an important role in this field. Pulsed Nd: YAG, dye and alexandrite lasers have given way to the holmium:yag laser in the endourological treatment of urinary lithiasis. METHODS: More than one lithotripter are often required for percutaneous nephrolithotomy of great volume stones, and ballistic and electrokinetic lithotripters are generally preferred due to their high performance. The best indications for Holmium laser is the treatment of caliceal stones far from the pelvis, only accessible through flexible nephroscopes. Midi and minipercs, renal lithiasis in children and some earthy calculi, of low consistency, are also good indications for it. Depending on the anatomical characteristics of the kidney and localization, number, size and hardness of the stone 200, 365, or 500 nanometer fibers may be employed. Due to the fact that the laser drills a hole in the stone like if it is a thermal barrier, it may break in different ways: applying the quartz fiber in between the layers, drilling all the interior before breaking the surface, or drilling multiple points to weaken it and creating broad fracture lines. To accelerate the breaking process one can choose to use larger fibers or to modify the settings of the equipment increasing the potency, although this has some potential risk for the kidney. RESULTS: The theoretical 100% of good results is reduced due to multiple technical and anatomical factors: size, number, localization, and hardness of the stone, as well as the possibility of reaching and seeing the calculus and being able to place the tip of the fiber against it. CONCLUSIONS: Although the holmium laser develops on excellent role at the time of avoiding leaving residual calculi or diminishing the number of them, sometimes the electrohydraulic lithotripsy is more effective.