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OBJECTIVE: To describe a more general,less restrictive approach to stone formation that takes intoaccount experimental data and to develop a hypothesis ofstone formation based on experimental, molecular biologyand clinical findings.METHODS/RESULTS: Stone formation is reviewed inthe light of the authors' findings by means of an appropriateexperimental method in an attempt to understand fundamentalaspects of urolithiasis. This project, which iscurrently under discussion, attempts to provide answers tothe physiopathological issues of this old disease.CONCLUSIONS: Observation of the experimentalphenomena that result in stone formation constitutes anew approach that can provide further insight into stoneformation.
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OBJECTIVE: The existence ofmicroinfections produced by bacteria of a very small size(nanobacteria) could be a risk factor for stone formation.The results of a study to detect the presence of nanobacteriain calculi are presented.METHODS: 1,000 calculi (excluding struvite calculi)were analyzed by macroscopic and microscopic techniques.RESULTS: Microorganisms were detected in only 5calculi (0.5%). All these calculi had developed in cavitieswith low urodynamic efficacy. The microorganisms werelocated in the center of the calculus and the main componentwas calcium oxalate monohydrate or uric acid. Ammoniumurate / sodium urate were frequently found to be a minorcomponent in the center of the calculus. The only commonbiochemical urinary alteration observed in these patientswas a urinary pH below 5.5; conventional urine cultureswere always negative.CONCLUSIONS: Our findings demonstrate that thesebacteria can play an important role in the development ofcalculus by inducing the formation of heterogeneousnucleants of calcium oxalate and uric acid. According toour results, however, this mechanisms is not common andwould also be associated to other lithogenic risk factors.It is important to underscore that the majority of patientssuffered from stomach ulcers and/or gingivitis which areconditions that could be induced by the same type ofmicroorganisms. Therefore, it can be deduced that similarbacterial factors might be involved in pathologies thathave as yet not been related. Further studies are warrantedto clearly identifty these bacteria.
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OBJECTIVE: To present a simple classification of the most frequent renal calculi that relates each type of calculus with the main possible etiologic factors linked to its formation (mainly urinary biochemical parameters).METHODS: The macro, microstructure and composition of 2,500 renal calculi were studied by appropriate combination of stereoscopic microscopy, IR spectroscopy and scanning electron microscopy + X-ray microanalysis. The information obtained were related with the main urinary biochemical parameters, determined by conventional analytical procedures.RESULTS: Ten main categories of renal stones, covering over 95% of all conceivable calculi, are distinguished based on their composition and structure. Etiologic factors, mainly urinary biochemical parameters, leading to the formation of stone of every category are specified.CONCLUSIONS: From the detailed study of the renal calculus important etiologic factors can be deduced. Such information complements and confirms the urinary biochemical studies. As a consequence, the corresponding treatment can be better established.
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OBJECTIVE: Extracorporeal shock wavelithotripsy (ESWL) is a technique that is not free of adverseeffects. Renal changes detected during complementaryexploratory procedures have been described, althoughthese are minimal, resolve within a few days, do notpresent clinical manifestations and are not detected onultrasound in most of the cases. For this reason, we studieda marker for renal injury, the urinary excretion ofglycosaminoglycans (GAG) in patients with renal calculi,before, immediately after and 30 days following ESWL.The novelty of the study lies in that we have classified thepatients with calculi according to the degree of renalfunction before ESWL, since it is recognized that theobstructive features of lithiasis can cause some degree ofrenal impairment.METHODS: Urinary GAG was quantified according tothe colorimetric method described by Pennock.RESULTS: Urinary GAG levels were found to be lowerin patients with renal calculi and preserved renal functionthan in healthy control subjects. In the presence of renal failure, these levels are elevated due to the obstructivenephropathy caused by calculi. Urinary GAG significantlyincreased post-ESWL in patients with renal lithiasis andpreserved renal function or renal failure. At 30 days postESWL, GAG returned to pre-test levels.CONCLUSIONS: Quantification of urinary GAG is auseful biochemical method in the evaluation of renalparenchymal injury produced by ESWL.
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OBJECTIVE: To report one case of a rare disease. METHODS: 39-year-old male patient presenting with the suspicion of sexually transmitted disease. We show several pictures of a clinical case diagnosed and treated in our hospital. We performed a bibliographic review on the disease and present its etiology, diagnosis and treatment. RESULTS: We concluded it was Bechet’s disease because of the past medical history, clinical presentation, and diagnostic tests (positive pathergy test). CONCLUSIONS: Although it is a rare disease, we should always think of the diagnosis of Bechet’s disease in a patient with genital ulcers non responsive to treatment.
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OBJECTIVE: To review the indicationsand complications of the use of endourological cathetersin the treatment of urinary lithiasis and choice of catheterbased on its physical and hydrodynamic characteristicsand biocompatibility.METHODS: Data from our experimental and clinicalstudies, as well as those published in the literature aresummarized.RESULTS: Polyurethane, C-flex and Percuflex cathetershave the highest retaining capacity, while the silicone,Urosoft and Wiruthan catheters have the lowest. Thetensile strength of polyurethane and copolymers is superiorto that of silicone. The friction coefficient, whichvaries within the same material, influences the facility ofcatheter insertion. The number and size of the side ventsare essential to catheter hydrodynamic behavior. Siliconeis the most biocompatible material, followed by Urosoft.The polyurethanes and C-flex catheters cause importanturothelial hiperplasia and edema of the lamina propia.CONCLUSIONS: The choice of endourological cathetershould be individualized and based on the clinicalindication. For prevention of obstruction from steinstrassepost- lithotripsy, a catheter with a high extraluminal flow and high retaining capacity is indicated to facilitatepassage of stone fragments and to avoid catheter migration.
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OBJECTIVE: To review currentmanagement of renal calcium stones.METHODS: Data from our experience are presentedand the literature is reviewed. The results and indicationsof treatment are analyzed.RESULTS/ CONCLUSIONS: Pyelic calculi are the bestindication for ESWL. The success rate ranges from 33%-90% and is influenced particulary by stone size andcomposition. Similar results are achieved for calycealcalculi, although the overall complete resolution rate is50%-75% for stones in the lower calyces versus 90% forPNL. Furthermore, the resolution rate is even lower if theinfundibulo-pyelic angle is less than 90 degrees. Theresolution rate ranges from 4%-58% for intradiverticularcalculi and the best results are obtained when the calculusis small and the neck of diverticulum can be visualized aturography. The staghorn stone is the most complex andoffers more difficulties to treatment by ESWL. Goodresults are achieved only in the staghorn type I (72%resolution; mean 3.5 sessions per patient).
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OBJECTIVE: To evaluate the treatment ofurinary calculi in renoureteral malformations.METHODS: From April 1988 to December 2000, wehave treated 158 patients with renoureteral malformations(36 horseshoe kidneys, 32 caliceal diverticula, 2megacaliosis, 2 crossed renal ectopy, 3 polycystosis, 7hydrocalyx, 24 complete duplex ureter, 18 incompleteduplex ureter, 22 ureterocele, 2 segmental megaureter).RESULTS: Renoureteral malformations were diagnosedin 158 of 19,000 patients that were treated in our stone unitfrom April 1988 and December 2000.Horseshoe kidney: 54% of the patients treated byESWL are stone-free; PNL was performed in 2 patientsand conventional surgery in another 2 patients.Caliceal diverticulum: 42% of the patients treated byESWL are stone-free; 3 patients underwent conventionalsurgery.Other renal malformations: 62% of the patients treatedby ESWL are stone-free.Ureteral malformations: duplex ureter and megaureter:82% of the patients treated by ESWL are stone-free.Ureterocele: due to the poor results achieved by ESWL,we performed endoscopic transurethral meatotomy.CONCLUSIONS: These results indicate that ESWLalone can be considered to be the treatment of choice forsmall calculi in patients with renal malformations, althoughwe consider it to be mandatory to perform individualassessment of the urinary tract and stone size in thesepatients in order to choose the best therapeutic option.The same criteria for the normal urinary tract can beapplied in ureteral malformations except ureteroceles, forwhich we advocate performing endoscopic surgery forstone removal.
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OBJECTIVE: To establish the criteria fortreatment of staghorn stones according to stone surfaceand distribution in cadaver kidneys.METHODS: Retrospective study of 344 cases treatedfrom 1985 to 1992 and classified into two groups accordingto treatment by extracorporeal lithotripsy or bypercutaneous nephrolithotomy (PNL).RESULTS: Mean age 48.69 years, prevalence of femalesand positive urinary culture in almost 70%, mainly Proteus.Stone composition was varied, but mainly magnesiumammonium phosphate. Treatment was by extracorporeallithotripsy in 80.81% and by PNL in 19.9%.CONCLUSIONS: Treatment of this type of lithiasisshould be by combined surgical removal and medicaltreatment. Lithotripsy is advocated for large calicealcalculi and PNL for large pyelic calculi.
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OBJECTIVE: To review the history, development, indications and current methods of percutaneous renal lithotripsy.METHODS: The history and development of PNL is briefly reviewed. Its indications are analyzed, starting with large calculi and covering all the indications over the last 15 years of development of this technique and its current use. The PNL technique currently performed in our Lithotripsy Unit is described step by step. Technical details, equipment, instruments, complications and solutions are discussed.RESULTS/CONCLUSIONS: In our view, PNL continues to be the technique of choice for most of the calculi that are more than 2 cm in size.It is fundamental for the new generation of urologists to be familiar with all endourologic techniques since current technological advancements will allow us to perform procedures throughout the urinary tract using endoscopic methods.
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OBJECTIVE: To present our results withESWL in situ in the treatment of ureteral lithiasis. Distalureter calculi can be managed by ESWL or URS. For complex ureteral calculi associated with ureteralmalformations, failed ESWL or complications otherprocedures are utilized (URS) and open surgery has itsindications.METHODS: From October 1990 to December 2000 theLithiasis-Lithotripsy Unit of the FJD has performed 2,500ESWL in situ for ureteral calculi without endoscopic orpercutaneous procedures (double-J or PN). The calculuswas located in the lumbar ureter in 45%, sacro-iliac in11% and renal pelvis in 44%. 67% were males and 33%females (mean age 48 and 42 years, respectively). Stonesize was 5-20mm in 88% of the cases; 1.5% had bilateralinvolvement, 1.7% multiple and 1.5% had a solitarykidney. 15% had renal colic when the procedure wasperformed. IVP was performed during ESWL for ureteraluric acid stones.RESULTS: The overall success rate was 95%; 97% forstones in the lumbar ureter and 89% for stones in the distalureter. Repeat-ESWL rate was 1.10. Renal colic resolvedduring ESWL, although stone fragmentation was partial.Hematuria is common post-ESWL and irritative voidingsymptoms on passage of stone fragments. Post-ESWLcolic was observed in 20% of the cases but were managedwithout difficulty with medication. There were 3 cases ofsevere complications (0.12%), colon perforation, severerenal hematoma and peritonitis. Septic obstruction wasfound in 1.5% that required catheterization or nephrostomy.Radiologic and asymptomatic Steinstrasse was observedin 10% of the cases.CONCLUSIONS: ESWL in situ is the treatment ofchoice in ureteral lithiasis and has been demonstrated bymany groups. The size and degree of stone impaction havea negative influence on the results. Resistance tofragmentation, which is basically determined by stonechemical composition, influence the results. Monohydratecalcium oxalate stones have been found to be the mostresistant. Previous insertion of a catheter (double-J ornephrostomy) does not enhance the results. It appears tobe useful during an episode of renal colic. Distal ureteralcalculi can be treated by ESWL and URS. If a lithotriptoris available, ESWL without endoscopic procedures is thefirst choice.
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OBJECTIVE: To present the results achieved in the treatment of 1802 distal ureteral stones treated at the Lithotripsy Unit of the San Cecilio University Hospital over the last 10 years (1990-2000). METHODS: Stones were treated by extracorporeal shock wave lithotripsy (ESWL) or ureteroscopy (URS). ESWL was the initial treatment in 81% of the cases (1460 calculi) and URS in the remaining 19% (342 stones). URS was performed for complication or failed ESWL (102 stones) and ESWL was performed for failed URS, basically due to stone migration (24 stones). Ureterolithotomy was required on 7 occasions. Sedation-analgesia with fentanyl and midazolam was routinely used in URS. Sedation was required in only 55% of the ESWL procedures. RESULTS: Elective ESWL resolved 93% of the cases, a percentage which is similar to that achieved with URS as first treatment. The ESWL retreatment rate was 1.3. URS was successful in 98% of the cases of failed ESWL. CONCLUSIONS: There are two treatment modalities for stones in the distal ureter: ESWL and URS. We advocate the use of outpatient URS with sedation preferably in the female patient, impacted stones, obstructive uropathy, stones larger than 2 cm and radiotransparent stones.
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OBJECTIVE: Cystine renal stone is theonly clinical consequence of cystinuria, an autosomalrecessive hereditary disease that affects an average of 1out of 7,000 newborns, and whose geographical distributionvaries significantly. The diagnosis and treatment of thiscondition is reviewed in the light of the advances ingenetics and molecular biology.METHODS: The evolution of current knowledge aboutthis disease is reviewed.RESULTS/CONCLUSIONS: The advances over thelast 8 years have led to the characterization, at the presenttime, of two genes responsible for this disease, whichdemonstrates its polygenic origin. By phenotype, cystinuriacan be classified into two types: type 1 and non-type 1.Both types show genetic and biochemical, but not clinicaldifferences.From the therapeutic viewpoint, the main objective isto eliminate existing calculi and, above all, preventrecurrence by acting on the pathophysiologic mechanismsof renal cystine. Experience shows that despite the correctuse of our current therapeutic armamentarium and theapplication of the general guidelines discussed in thispaper, some cystinuric patients still maintain an importantstone-forming activity. Patient clinical evaluation and agenetic study of both patient and family will be decisive forphenotyping.
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To analize current clinical,diagnostic and therapeutic aspects of uric acid lithiasis.The role of helical CT in its diagnosis, ESWL andalkalinization in its treatment, and metabolic andcrystalographic analyses are discussed.METHODS: The incidence of uric acid calculi isestimated to be from 5% to 7% in the Lithiasis-LithotripsyUnit of the Jiménez Díaz Foundation. The diagnostic andtherapeutic possibilities of helical CT and ESWL areillustrated in a case of complex bilateral renal uric acidstaghorn stone.RESULTS:Ultrasound and endoscopic uroradiologyare fundamental in the diagnosis of radiotransparentobstructive bilateral renal stone. Ureteral catheterizationwas warranted due to the anuresis that resulted frombilateral obstructive renal failure. Stone dissolutioncombined with ESWL achieved rapid resolution of thelarge calculi.CONCLUSIONS: Helical CT without contrastenhancement should be performed along with theconventional urological diagnostic tests for ureterallithiasis, especially in patients with renal colic. Althoughurinary alkalinization is the conventional treatment foruric acid stones, ESWL permits faster resolution in large,obstructive or ureteral stones in patients with renal colic. Complete assessment of patients with uric acid calculiincludes metabolic and crystalographic analyses.
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OBJECTIVE: Although residual lithiasisafter the application of shock waves is a situation thatcoexists with the procedure, in some cases it can beconsidered to be a failure of ESWL. The natural historyand outcome of 244 cases of residual renal stone followedover a 5-year period are analyzed, and the approachbased on a pre-established classification is discussed..METHODS: Of 1,407 patients treated by ESWL forrenal lithiasis during 1995, 244 cases with a renal calculuslarger than 3 mm were followed for a period of 5 yearsafter treatment and evaluated by clinical, radiological,ultrasound and analytical methods.RESULTS: At 3 months post-ESWL, 1,013 cases (72%)were completely stone-free and 394 (28%) showed residualstone; of these, 244 (62%) had residual stone fragmentsgreater than 3 mm. At 5 years, 190 (78%) remained stableand the remaining 54 (22%) showed stone regrowth thatwarranted additional treatments: 52 ESWL, 1 PNL and 1partial nephrectomy. Despite the retreatments, only 42%became completely stone-free.CONCLUSIONS: A classification of residual renalstone can be established based on the data obtained toorient the approach in each case, although the frequencyof residual stone can be reduced by the appropriate indication of ESWL. Once a renal stone has formedretreatments with ESWL cannot ensure completeelimination of the stone.
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OBJECTIVE: To identify significantdifferences in the metabolic changes observed in patientswith single and those with recurrent episodes of calciumurinary lithiasis.METHODS: From August 1993 to January 1999,outpatient metabolic evaluation was performed on 106patients (49 males, 57 females) with a single episode ofcalcium urinary lithiasis and 394 patients (177 males, 217females) with recurrent calcium urinary lithiasis (170mild and 224 severe). 24-hour urine was collected by thepatient on days 2 and 3 after a low calcium diet (400 mg/day calcium) and total volume, calcium, phosphate, uricacid, creatinine, sodium, potassium, oxalate, magnesiumand citrate were determined. On day 4 a blood sample wasobtained to analyze creatinine, calcium, phosphate, uricacid, sodium, potassium and magnesium. Density, pH andammonium were analyzed in a urine sample. Then thepatient received 1 g basic calcium and urine was collectedduring a 4-h period to determine calcium and creatininelevels.RESULTS:In the patients with recurrent lithiasisshowed a higher frequency of hypercalciuria, analkaline urinary pH and higher urinary calcium than patients with a single episode of lithiasis.Patients with recurrent lithiasis were younger when theyhad their first episode than the patients with asingle episode of lithiasis. Hypercalciuria was found in36.9% of the patients with a single episode, 41.7% inpatients with mild and 51.4% in patients with severerecurrent lithiasis. Alkaline urinary pH was found in 3.5%of patients with mild recurrent and 3.6% of those withsevere recurrent lithiasis and in none of the patients witha single episode. 24-h urinary calcium was 169 ± 83 mgin patients with a single episode, 183 ± 89 mg in those withmild recurrent and 192 ± 98 in those with severe recurrentlithiasis. The mean age at the time of the first episode oflithiasis was 43.7 years for those with a single episode,40.4 years for those with mild recurrent and 34.6 for thosewith severe recurrent lithiasis.CONCLUSIONS: Patients with calcium urinary lithiasiswith high urinary calcium levels or alkaline urinary pHare related with a higher rate of recurrence and thereforerequire regular clinical monitoring and selective medicaltherapy if necessary to prevent new episodes of lithiasis.
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OBJECTIVE: To analyze the biochemicalimpact of treatment with phosphates in patients withrecurrent calcium lithiasis and hypercalciuria.METHODS: 20 patients were selected according to thefollowing criteria: normal renal function, recurrent calciumnephrolithiasis, hypercalciuria, hypophosphatemia, normal calcium and low tubular phosphate reabsorption(TPR).The mean duration of treatment was 7.5± 3.8 months.The pre and post-treatment phosphatemia, calciuria,phosphaturia and TPR were analyzed. The results wereanalyzed by the Wilcoxon statistical method.RESULTS: We found a moderate but significant decreaseof calciuria (326.5 ± 52-4 to 266.4 ± 31.7 mg/24 h), whilephosphatemia (2.21 ± 0.09 to 2.52 ± 0.30 mg/24h) andTPR (65.7 ± 6.3 to 71.3 ± 4.1) increased significantly.Overall treatment was well-tolerated and no patientabandoned treatment.CONCLUSIONS: The short-term biochemical resultsobtained are similar to those reported in the literature.However, definitive conclusions cannot be made sincetreatment application is not standardized and studies thatdemonstrate its clinical efficacy are scanty.
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OBJECTIVE: The physiologic effects ofpotassium citrate on urinary solubility have led to theiruse to facilitate stone passage after lithotripsy. The aim ofour study is to evaluate the foregoing effects and theefficacy of long-term treatment with potassium citrate toprevent stone recurrence in patients undergoingextracorporeal shock wave lithotripsy.METHODS: A prospective study was conducted on 100patients with calcium oxalate or calcium phosphatenephrolithiasis that had undergone treatment byextracorporeal shock wave lithotripsy (ESWL). The patientswere divided into 4 groups: patients that were stone-freetreated with potassium phosphate (25 cases) or fluid diet(25 cases) and patients with persistent residual lithiasis treated with potassium citrate (25 cases) or fluid diet (25cases). Calculi were classified according to the changesobserved during the study compared with the pre-studystatus as stable (no changes from the pre-study status, withor without residual stone), increased (increase in numberor size of the residual stone or recurrence), and decreased(decrease in number or size or passage of the residualstone).RESULTS: Of the 50 patients treated with potassiumcitrate, 35 (70%) remained stable, 10 cases (20%) showeda decrease and 5 (10%) showed an increase. Of the 50patients on fluid diet, 19 (38%) remained stable throughoutthe study, 4 (8%) showed a decrease and 27 (54%) showedan increase in stone size or number. The number of stonerecurrence throughout the study in the 100 patients was 25(25%); of these, 8 were in patients treated with potassiumcitrate and 17 of those that did not receive potassiumcitrate.CONCLUSIONS: Potassium citrate therapy has beenfound to be statistically significantly effective in thecontrol of post-lithotripsy residual stone and stonerecurrence
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OBJECTIVE: To analyze the role of thiazidetherapy in the prevention of recurrent calciumnephrolithiasis, considering the hypocalciuric action ofthis drug.METHODS: A prospective study before and aftertreatment, with a 3-year follow-up, was carried out on 150patients with recurrent calcium renal stone. The patientswere divided into three groups: (A) no treatment, (B)treatment with thiazide 50 mg/day and (C) treatment withthiazide and potassium citrate. The treated groups wererandomly assigned to the treatment arms. Controlanalytical tests and radiological assessments wereperformed regularly.RESULTS:Excellent results were achieved with thiazidetherapy in regard to stone recurrence and changes inresidual stone in comparison to the group of untreatedpatients (group A). The most common metabolic disorderwas absorptive hypercalciuria type I. Most of the patientsshowed a single metabolic disorder. The side effects weregenerally not relevant.CONCLUSIONS: Thiazides should be considered asthe first line of treatment in absorptive and excretoryhypercalciuria. We believe that in unselected patientswith calcium stone, thiazide therapy can be effective in itsprevention. It is important to take into account the possibleside effects of the drug and supplementation with potassiumcitrate for thiazide-induced hypocitraturia.
