Role, Cost, and Availably of Urinary pH Monitoring for Kidney Stone Disease-A Systematic Review of the Literature.

PURPOSE OF REVIEW: Urinary pH is an important factor related to renal stone disease, and it plays an essential role in stone prevention. Monitoring of urinary pH by patients at home provides information that can help to assess the treatment needed by each patient. We conducted a systematic review is to assess the available evidence concerning urinary pH monitoring methods along with their accuracy, cost, and usefulness by patients with urolithiasis. RECENT FINDINGS: A total of 9 articles were included (1886 urinary pH measurements). They reported information about urinary dipsticks, portable electronic pH meters and electronic strip readers, amongst other methods. Accuracy was compared with a laboratory pH meter (gold standard). Urinary dipsticks were found to be not accurate enough to guide clinical decision making and portable electronic pH meters showed promising results. Urinary dipsticks are neither precise nor accurate enough. Portable electronic pH meters seem to be more accurate, easy to use, and cost-effective. They are a reliable source for patients to use at home in order to prevent future episodes of nephrolithiasis.

The new concept of ureteral access sheath with guidewire disengagement: One wire does it all.

PURPOSE: To prospectively evaluate the new Flexor©Parallel™ Rapid Release™ (Cook(®), Bloomington, IN, USA) access sheath (UAS) which allows the use of a single wire to serve as both safety and working guide. MATERIALS AND METHODS: Between June and September 2014, adult patients from five European centers who underwent flexible ureteroscopy (fURS) for therapeutic and diagnostic purposes were included. The 12/14Fr Flexor©Parallel™ UAS was evaluated. Data were collected and examined by both univariate and multivariate analyses. The UAS material and usage characteristics were rated per case by the surgeons on a scale from very bad to very good. RESULTS: In total, 134 UASs were used in 67 male and 67 female patients. Fifty percent of ureters (67 patients) were pre-stented. Ninety percent of the procedures were therapeutic. The overall successful insertion rate was 94 %. Pre-stenting status was the only independent factor for a successful access sheath insertion: 98.5 % of the pre-stented patients had a successful UAS placement vs. 82 % of non-pre-stented (p = 0.001, C.I. 95 %: 1.2). Evaluation of the material and radiopacity was considered very good in over 90 % of cases. Release of the guidewire, hydrophilic coating, gliding of the endoscope and repeatability were considered very good in over 80 %. There were two (1.4 %) UAS malfunctions and one submucosal lesion reported. CONCLUSIONS: The use of the Flexor©Parallel™ Rapid Release™ (Cook(®), Bloomington, IN, USA) with usage of a single guidewire in a prospective multicentric scenario was clinically applicable in the majority of cases. Pre-stenting increased the chance of a successful insertion from 82 to 98.5 %.

Lower pole stones: prone PCNL versus supine PCNL in the International Cooperation in Endourology (ICE) group experience.

PURPOSE: To assess efficacy and safety of prone- and supine percutaneous nephrolithotomy (PCNL) for the treatment of lower pole kidney stones. METHODS: Data from patients affected by lower pole kidney stones and treated with PCNL between December 2005 and August 2010 were collected retrospectively by seven referral centres. Variables analysed included patient demographics, clinical and surgical characteristics, stone-free rates (SFR) and complications. Statistical analysis was conducted to compare the differences for SFRs and complication rates between prone- and supine PCNL. RESULTS: One hundred seventeen patients underwent PCNL (mean stone size: 19.5 mm) for stones harboured only in the lower renal pole (single stone: 53.6%; multiple stones: 46.4%). A higher proportion of patients with ASA score ≥ 3 and harbouring multiple lower pole stones were treated with supine PCNL (5.8 vs. 23.1%; p = 0.0001, and 25 vs. 81.5%; p = 0.0001, respectively, for prone- and supine PCNL). One-month SFR was 88.9%; an auxiliary procedure was needed in 6 patients; the 3-month SFR was 90.2%. There were 9 post-operative major complications (7.7%). No differences were observed in terms of 1- and 3-month SFRs (90.4 vs. 87.7%; p = 0.64; 92.3 vs. 89.2%; p = 0.4) and complication rates (7.6 vs. 7.7%; p = 0.83) when comparing prone- versus supine PCNL, respectively. CONCLUSIONS: The results confirm the high success rate and relatively low morbidity of modern PCNL for lower pole stones, regardless the position used. Supine PCNL was more frequently offered in case of patients at higher ASA score and in case of multiple lower pole stones.

Bowel Perforation after Extracorporeal Wave Lithotripsy: A Review of the Literature.

INTRODUCTION: Extracorporeal wave lithotripsy (ESWL) is considered a first-line treatment for renal and ureteral stones up to 10-20 mm in diameter. Complications are uncommon, with a reported rate of 0-6% in the literature. Bowel perforation has only been described in a few case reports but requires rapid diagnosis and treatment. METHODS: A review of the literature from PubMed/Medline, Embase, Cochrane, and Web of Science databases was performed including studies reporting bowel perforation secondary to ESWL between January 1990 and June 2022. RESULTS: We found 16 case reports of intestinal perforation in the literature. Although some patients had previously undergone abdominal surgery or had inflammatory intestinal disease, others were without comorbidities that could lead to complications. Abdominal pain was the main symptom and imaging was required to confirm the diagnosis, which usually necessitated a surgical intervention. As regards the ESWL technique, it appears that the combination of a high energy level and the prone position constitutes a risk factor for these rare complications. At the authors' centre, only one case has been reported among 24,000 ESWL procedures over 20 years: A 59-year-old female who underwent ESWL for a distal right ureteral stone presented acute abdominal pain and free intraperitoneal pelvic fluid on ultrasound. A CT scan revealed a small bowel perforation requiring open laparotomy with primary closure. CONCLUSIONS: In conclusion, although bowel perforation after ESWL is rare, progressive abdominal pain with tenderness at physical examination requires proper imaging evaluation to exclude bowel perforation and prompt intervention if required.

Use of Moses 2.0 with extended frequency and optimized Moses vs. high-power laser in MiniPCNL: a randomized controlled trial.

The aim of the study was to compare standard high-power laser (with < 80 Hz) to extended frequency (> 100 Hz) lithotripsy during miniPCNL. 40 patients were randomized in to two groups undergoing MiniPCNL. For both groups, the Holmium Pulse laser Moses 2.0 (Lumenis) was used. For group A, standard high-power laser with < 80 Hz, with Moses distance was set using up to 3 J. For Group B, extended frequency (100-120 Hz) was used allowing up to 0.6 J. All patients underwent MiniPCNL using an 18 Fr balloon access. Demographics were comparable between groups. Mean stone diameter was 19 mm (14-23) with no differences between groups (p = 0.14). Mean operative time was 91 and 87 min for group A and B (p = 0.71), mean laser time was similar in both groups, 6.5 min and 7.5 min, respectively (p = 0.52) as well as the number of laser activations during the surgery (p = 0.43). Mean Watts used was 18 and 16 respectively being similar in both groups (p = 0.54) as well as the total KJoules (p = 0.29). Endoscopic vision was good in all surgeries. The endoscopic and radiologic stone free rate was achieved in all patients expect for two in both groups (p = 0.72). Two Clavien I complications were seen, a small bleeding for group A and a small pelvic perforation in group B. The use of high-power holmium laser with extended frequency and optimized Moses was effective and safe being comparable to standard high-power laser for MiniPCNL allowing more versatility with the setting range.

New Generation Pulse Modulation in Holmium:YAG Lasers: A Systematic Review of the Literature and Meta-Analysis.

(1) Background: New pulse modulation (PM) technologies in Holmium:YAG lasers are available for urinary stone treatment, but little is known about them. We aim to systematically evaluate the published evidence in terms of their lithotripsy performance. (2) Methods: A systematic electronic search was performed (MEDLINE, Scopus, and Cochrane databases). We included all relevant publications, including randomized controlled trials, non-randomized comparative and non-comparative studies, and in-vitro studies investigating Holmium:YAG lithotripsy performance employing any new PM. (3) Results: Initial search yielded 203 studies; 24 studies were included after selection: 15 in-vitro, 9 in-vivo. 10 In-vitro compared Moses with regular PM, 1 compared Quanta's, 1 Dornier MedTech's, 2 Moses with super Thulium Fiber Laser, and 1 compared Moses with Quanta PMs. Six out of seven comparative studies found a statistically significant difference in favor of new-generation PM technologies in terms of operative time and five out of six in fragmentation time; two studies evaluated retropulsion, both in favor of new-generation PM. There were no statistically significant differences regarding stone-free rate, lasing and operative time, and complications between Moses and regular PM when data were meta-analyzed. (4) Conclusions: Moses PM seems to have better lithotripsy performance than regular modes in in-vitro studies, but there are still some doubts about its in-vivo results. Little is known about the other PMs. Although some results favor Quanta PMs, further studies are needed.

Epidemiological, clinical and laboratory differences between male urethral infections due to Haemophilus spp. and those due to Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium and Ureaplasma urealyticum: A descriptive study.

OBJECTIVE: To describe the epidemiological, clinical and laboratory characteristics of male patients diagnosed with Haemophilus spp. urethral infection and to compare them with the characteristics of male patients diagnosed with N. gonorrhoeae, C. trachomatis, M. genitalium and U. urealyticum urethral infection. Over the past 2 years, an increase in urethral infections due to Haemophilus spp. was observed. MATERIALS AND METHODS: All male patients who attended our Department of Sexually Transmitted Infections between January 2018 and February 2019 were retrospectively studied; they underwent conventional bacteriological and multiplex PCR studies in the urethra at the same time. RESULTS: Of the 86 patients studied, a unique microorganism was detected in 76 cases, N. gonorrhoeae in 24, Haemophilus spp. in 21 (16 H. parainfluenzae and 5 H. influenzae), C. trachomatis in 19, M. genitalium in 8 and U. urealyticum in 4; 10 cases presented more than one microorganism. In case of multiple aetiological agents, sexual partnership was multiple. In the Haemophilus group, 81% reported only unprotected oral insertive sex; symptoms lasted for more than one week in 62% of the patients. CONCLUSIONS: Haemophilus is an aetiological agent of non-gonococcal urethritis whose incidence is clearly increasing; the main route of transmission is oral sex. The most common reason for consultation is dysuria and testicular pain, while urethral discharge was predominant for the other causes of urethral infection. Due to the high frequency of antibiotic resistance in the Haemophilus group, it is necessary to confirm eradication by performing a test of cure.

Systematic Review and Meta-Analysis Comparing Fluoroless Ureteroscopy and Conventional Ureteroscopy in the Management of Ureteral and Renal Stones.

Context: Stone recurrence is frequent in stone formers, and repeated diagnostic and therapeutic procedures in recurrent stone formers place patients and urologists at a significant risk of radiation-related effects. Objective: To assess the efficacy and safety of fluoroless ureteroscopy (fURS) compared with conventional ureteroscopy (cURS) in the management of ureteral and renal stones. Evidence Acquisition: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies providing data on the stone-free rate (SFR), secondary procedures, operative time (OT), and complication rate for fURS and cURS were included. An overall analysis and a subgroup analysis based on the stone target (ureteral stones, renal stones, or a combination thereof) were performed. Evidence Synthesis: A total of 23 studies were included, recruiting 4029 patients. Pooled data showed that in comparison with cURS, fURS exhibited a similar SFR (odds ratio [OR]: 0.99; 95% confidence interval [CI]: 0.92 to 1.06; p = 0.709), without significant differences in overall intraoperative complication rate (OR: 0.73; 95% CI: 0.33 to 1.63; p = 0.446), overall postoperative complication rate (OR: 0.98; 95% CI: 0.59 to 1.63; p = 0.949), major postoperative complication rate (Clavien ≥3; OR: 0.46; 95% CI: 0.14 to 1.53; p = 0.205), OT (standardized mean difference [SMD]: 0.07; 95% CI: -0.15 to 0.29; p = 0.537), hospital stay (SMD: -0.12; 95% CI: -0.26 to 0.02; p = 0.084), or secondary procedures (OR: 1.20; 95% CI: 0.58 to 2.49; p = 0.616). The subgroup analysis revealed no differences in outcomes according to the stone target. We also identified a rate of conversion to the conventional technique of 5% (95% CI: 3% to 7%). Conclusions: The available data suggest that for the treatment of ureteral and renal stones, fURS offers a similar SFR to that provided by the cURS without any increase in complication rate, OT, hospital stay, or secondary procedures. Critical review of the dogmatic routine use of fluoroscopy during ureteroscopy may be warranted.

Oral Acidification with l-Methionine as a Noninvasive Treatment for Encrusted Uropathy.

Background: Encrusted uropathy (EU) is a rare disease caused by urea-splitting bacteria, most commonly Corynebacterium urealyticum, whose incidence is increasing. Standard treatment is based on pathogen-directed antibiotic therapy, urinary diversion, bladder instillations, and surgical resection of urinary calcifications. Case Presentation: We present the case of a 60-year-old man with symptomatic bilateral encrusted pyelitis and cystitis with acute renal failure. We initially treated the patient with antibiotic therapy, urinary diversion, and oral acidification with acetohydroxamic acid, achieving negative urinary cultures. Because of the persistence of encrusted pyelitis, the patient was discharged on oral l-methionine 500 mg bid and 12 months later the encrustations had almost disappeared. Finally, we performed right retrograde intrarenal surgery to remove a persistent small calcification. Conclusion: Oral urinary acidification with l-methionine is a valid treatment for urinary encrustations in EU, with no complications reported. Complete resolution of the calcifications may be achieved without the need for invasive processes and unnecessary manipulation of the urinary system.

First clinical evaluation of the new single-use flexible and semirigid Pusen ureteroscopes.

INTRODUCTION: The purpose of the present study was to clinically evaluate two new single-use Pusen ureteroscopes, one semirigid with a flexible tip (srURS) and one flexible (fURS). MATERIALS AND METHODS: During ten consecutive procedures (five srURS and five fURS), we subjectively evaluated on a scale from 0 (poor) to 10 (excellent), the scope's deflection, image quality, and maneuverability prior to, during and after the surgery. Patient demographics, complications with the devices, and troubleshooting were recorded. RESULTS: There were a total of ten patients, five of which were female while the other five were male. Mean age was 58.9 years. Seven patients had a single kidney stone with mean size of 9.6 mm (1.6-20 mm). Half of the patients were pre-stented. For the fURS, the preoperative image quality rating was 8.4 (8-10), compared with 6.8 (4-9) during surgery. The preoperative deflection rating was 9.6+ 0.9 (8-10), while during surgery this decreased to 8.0 (6-10) and to 6.0 (4-8) when using a laser fiber. The srURS had a preoperative image quality rating of 9.2 (8-10), which decreased to 7.6 (6-9) while using the scope. The deflection rating decreased from 9.4 (7-10) preoperatively to 7.0 (1-10) postoperatively, and a similar reduction was observed in the maneuverability rating, from 9.6 (8-10) to 7.4 (1-10). Ureteroscopy was considered as a standard in four of the fURS and three of the srURS procedures. The mean overall satisfaction rating was 6. CONCLUSIONS: The two new single-use ureteroscopes, one flexible and one semirigid, were considered to have allowed standard ureteroscopy in four and three out of the five procedures for each scope, respectively. The image quality, deflection, and maneuverability ratings decreased during the procedure for both scopes.

The True Ablation Effect of Holmium YAG Laser on Soft Tissue.

PURPOSE: The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue. MATERIALS AND METHODS: With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 µm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy. RESULTS: The overall mean ID was 2 mm (0.25-4.39) and the mean width was 1 mm (0.3-3.1). The mean coagulation thickness was 0.48 mm (0.25-1.73). The higher the frequency and energy, the deeper and wider was the incision p < 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p > 0.119. CONCLUSIONS: The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

[Epidemiology of urolithiasis in Spain: Review of published demographic data in the period 1977-2016.] / Epidemiología de la urolitiasis en España: revisión de los datos demográficos publicadosen el periodo 1977­2016.

OBJECTIVE: Epidemiological data on urolithiasis in Spain have appeared in publications especially local and regional level, with few referrals to Spanish national territory. The aim of this paper is to review and systematize the epidemiological data published on urolithiasis in Spain. METHODS: We reviewed publications in national and international scientific journals, meetings and conferences, and research reports (1977-2016). PubMed search (indexed papers) and manual bibliography search (not indexed works) were performed. Bibliometric data evaluated: Year of publication, geographic area, number of cases, sample type, study design and publishing format. Demographic systematization of data: age, age and frequency distribution by gender, family history, social stratum, profession, place of residence, ethnics, seasonality and dietary habits. RESULTS: Publications revised: 79 corresponding to 56 main authors. Selected publications with original data: 42 (2 composed by Part I and II, and 2 composed by paper and thesis), corresponding to 35 authors. Bibliometric and demographic data of all publications are displayed in tables, sorted by variables. CONCLUSIONS: The comprehensive review of studies on epidemiology in Spain constitutes a solid basis for future research about epidemiology of urolithiasis.

Mini-percutaneous nephrolithotomy with high-power holmium YAG laser in pediatric patients with staghorn and complex calculi.

INTRODUCTION: Shock wave lithotripsy (SWL) is the treatment of choice for most cases of renal lithiasis in children. Some cases, however, are refractory to SWL and may be associated with anatomic and metabolic changes or a large stone burden. In these circumstances, mini-percutaneous nephrolithotomy (mini-PCNL) is an option. OBJECTIVE: The aim was to assess the safety and efficacy of high-power holmium YAG (Ho:YAG) laser in mini-PCNL for staghorn calculi. PATIENTS AND METHODS: The clinical records relating to 35 mini-PCNLs (Table) performed between January 2008 and December 2012 in 33 patients (27 boys and 6 girls; mean age 7 years, range 2-18 years) were retrospectively reviewed. Twenty-two (66.7%) of the patients had undergone a previous SWL (28.6% three sessions). The mini-PCNL puncture technique used involved fluoroscopic guidance with the C arm at 0-90° in the supine position. An 18F tract was used. Stone fragmentation was performed with a high-power Ho:YAG laser (Lumenis 100 W). RESULTS: Ten of the mini-PCNLs (28.6%) were right sided, and 25 were left sided (71.4%). Stones were located in the lower calyceal group in 64% of patients and in the renal pelvis in 50%. The mean stone size was 4.46 cm(2) (range 3-13.20 cm(2)). The number of stones varied between one and 20, and 83.3% were radiopaque. The laser was set at 70 W (range 50-100 W) (3.5 J/pulse with a frequency of 20 pulses/s). The mean surgical time was 150 min. In 78% of patients, complete stone clearance was achieved, and the overall stone-free rate rose to 85% when residual stones were treated with either SWL or retrograde intrarenal surgery. No perioperative complications were seen. DISCUSSION: There are few reports in the literature concerning the use of a high-power laser for treatment of complex stones and the few that do exist relate to adults have similar results, showing it to be highly effective and safe, with low morbidity. Some limitations of the present study must be acknowledged. It was retrospective and a relatively small number of patients were included. However, randomized prospective studies are required to confirm our findings and conclusions. CONCLUSION: In the pediatric population, mini-PCNL with high-power Ho:YAG laser is feasible and safe and represents the technique of choice for complex renal stones.

Recurrence at three months and high-grade recurrence as prognostic factor of progression in multivariate analysis of T1G2 bladder tumors.

OBJECTIVES: To evaluate the risk factors for disease progression in the frequent subgroup of Stage T1G2 (World Health Organization 1973) bladder tumors using an analysis of a large cohort of patients with Stage T1G2 disease. METHODS: A cohort of 616 patients with Stage T1G2 were treated with transurethral resection and random bladder biopsies. The mean follow-up was 4.2 years. Univariate and multivariate analyses were done using Cox regression analysis. The independent variables were multiplicity, association with carcinoma in situ (CIS), tumor size, tumor recurrence at 3 or 6 months, tumor grade, and association with CIS at first recurrence. The dependent variable was progression to muscle-invasive disease. RESULTS: Progression to muscle-invasive disease was identified in 28 of the 616 patients (4.5%). On multivariate analysis, when considering recurrence at 3 months, this factor was the principal prognostic factor, with a relative risk of 4.0 (95% confidence interval 1.2-13.3), followed by the presence of high-grade disease or CIS at first recurrence (relative risk 2.8, 95% confidence interval 1.3-5.8) and CIS associated with the primary tumor (relative risk 1.8, 95% confidence interval 1.1-2.9). When considering recurrence at 6 months, more prognostic factors were involved for progression, including as multiple tumors, CIS associated with the primary tumor, recurrence at 6 months, and the presence of high-grade disease or CIS at the first recurrence. CONCLUSIONS: In primary urothelial T1G2 bladder cancer, recurrence at 3 months was the main prognostic factor related to progression. Additional factors were the association of CIS with the primary tumor and the presence of high-grade disease and/or CIS at first recurrence.

Epidemiología de la urolitiasis en España: revisión de los datos demográficos publicados en el período 1977-2016 / Current status of extracorporeal shock wave lithotripsy in urinary lithiasis. Epidemiology of urolithiasis in Spain: review of published demographic data in the period 1977-2016

OBJETIVO: Los datos epidemiológicos sobre urolitiasis en España han aparecido sobre todo en publicaciones de ámbito comarcal y autonómico, siendo escasas las de carácter nacional español. El objetivo de este trabajo es revisar y sistematizar los datos epidemiológicos publicados sobre urolitiasis en España en los distintos trabajos. MÉTODOS: Revisión de las publicaciones en revistas científicas nacionales e internacionales, reuniones y congresos, e informes de investigación (1977-2016). Búsqueda en PubMed (trabajos indexados) y rastreo bibliográfico manual (trabajos no indexados). Datos bibliométricos evaluados: año de publicación, zona geográfica, número de casos, tipo de muestra, diseño del estudio y formato de publicación. Datos demográficos sistematizados: edad, distribución de edad y frecuencia por género, antecedente familiar, estrato social, profesión, lugar de residencia, aspectos étnicos, estacionalidad y hábitos dietéticos. RESULTADOS: Publicaciones revisadas: 79, correspondientes a 56 autores principales. Publicaciones seleccionadas con datos originales: 42 (2 compuestas de parte I y II), correspondientes a 35 autores. Se muestran en tablas los datos bibliométricos y demográficos del conjunto de publicaciones, ordenados por variables. CONCLUSIONES: La revisión completa de trabajos sobre epidemiología en España constituye una base sólida para establecer futuras investigaciones epimiológicas sobre urolitiasis

OBJECTIVE: Epidemiological data on urolithiasis in Spain have appeared in publications especially local and regional level, with few referrals to Spanish national territory. The aim of this paper is to review and systematize the epidemiological data published on urolithiasis in Spain. METHODS: We reviewed publications in national and international scientific journals, meetings and conferences, and research reports (1977-2016). PubMed search (indexed papers) and manual bibliography search (not indexed works) were performed. Bibliometric data evaluated: Year of publication, geographic area, number of cases, sample systematization of data: age, age and frequency distribution by gender, family history, social stratum, profession, place of residence, ethnics, seasonality and dietary habits. RESULTS: Publications revised: 79 corresponding to 56 main authors. Selected publications with original data: 42 (2 composed by Part I and II, and 2 composed by paper and thesis), corresponding to 35 authors. Bibliometric and demographic data of all publications are displayed in tables, sorted by variables. CONCLUSIONS: The comprehensive review of studies on epidemiology in Spain constitutes a solid basis for future research about epidemiology of urolithiasis

Cistinuria y litiasis renal de cistina. Estudio y enfoque terapéutico / Cystinuria and cystine renal lithiasis: and therapeutic approach

La litiasis renal de cistina es la única consecuencia clínica de la cistinuria, enfermedad hereditaria de transmisión autosómica recesiva que afecta de promedio a 1 de cada 7.000 nacidos vivos, existiendo una gran variabilidad geográfica. Los avances realizados en estos últimos 8 años sobre la genética y biología molecular de la enfermedad han permitido caracterizar por el momento dos genes responsables, lo cual demuestra el origen poligénico de la enfermedad. Desde un punto de vista fenotípico clasificamos la cistinuria en dos tipos: el tipo I y el tipo no I, ambos presentan diferencias genéticas y bioquímicas pero no clínicas. Desde un punto de vista terapéutico el objetivo primordial será la eliminación de los cálculos existentes y sobre todo la prevención de la recidiva incidiendo en los mecanismos fisiopatológicos de la cistina a nivel renal. La experiencia nos indica que aún a pesar de emplear correctamente el arsenal terapéutico existente y aplicar las normas generales comentadas en este capítulo, algunos pacientes cistinúricos mantienen un índice de actividad litiásica importante. El estudio clínico-genético del paciente y su familia será decisivo para la catalogación fenotípica (AU)

Análisis y evolución de la litiasis residual tras la aplicación renal de ondas de choque / Analysis and outcome of residual stone fragments following schock wave lithotripsy

OBJETIVO: La litiasis residual tras la aplicación de ondas de choque es una situación consustancial a la propia técnica, aún así y en algunos casos puede considerarse como un fallo de la LEOC. Estudiamos la historia natural y evolución en 5 años de 244 casos de LR, valorándose la conducta a seguir a partir de una clasificación prefijada. MÉTODOS: De los 1407 pacientes tratados con LEOC sobre litiasis en área renal durante 1995 se seleccionan 244 casos en que se detectó LR por encima de los 3 mm, estudiando su evolución durante los 5 años siguientes, utilizando métodos clínicos, radiológicos, ecográficos y analíticos. RESULTADOS: A los 3 meses de la LEOC 1013 casos (72 por ciento) se encontraban totalmente libres de cálculos y en 394 (28 por ciento) se detectó LR, de estos, el 62 por ciento (244) presentaban fragmentos superiores a 3 mm. En 5 años, 190 casos (78 por ciento) permanecieron totalmente estables y en los otros 54 (22 por ciento) se observó un crecimiento que obligó a tratamientos adicionales: LEOC en 52, NLP en uno y Nefrectomía parcial en otro. A pesar de los retratamientos efectuados, sólo un 42 por ciento de los casos quedaron definitivamente limpios de litiasis. CONCLUSIONES: En base de todos los datos obtenidos puede establecerse una clasificación de la LR que orientará sobre la conducta a seguir en cada caso, aunque la frecuencia de LR puede reducirse ajustando las indicaciones de la LEOC. Una vez instaurada la LR los retratamientos con LEOC no garantizan la total eliminación de la litiasis (AU)