Pneumatic Lithotripsy versus Holmium Laser Lithotripsy in Percutaneous Nephrolithotomy for Patients with Guy's Stone Score Grade IV Kidney Stone

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the efficacy and reliability of holmium (Ho:YAG) laser lithotripsy (HLL) and pneumatic lithotripsy (PL) in percutaneous nephrolithotomy (PCNL) in the treatment of patients with Grade IV kidney stones based on Guy's Stone Score.

STUDY DESIGN/MATERIALS AND METHODS

This retrospective study included 103 patients with Grade IV kidney stones out of 440 patients who underwent PCNL through HLL and PL in Second Affiliated Hospital of Shantou University Medical College, China, from January 2016 to December 2018. We analyzed preoperative, intraoperative, and postoperative variables of the patients to evaluate the efficacy and reliability of PCNL procedures.

RESULTS

Patients were categorized as Grade I, II, III, and IV, and the patients of each grade were 85 (19.32%), 39 (8.86%), 213 (48.41%), and 103 (23.41%), respectively. In Grade IV, the total operative time (min) for the PL and HLL groups was 137.7 ± 47.79 and 134.27 ± 53.38, respectively (p = 0.744). The variation in laboratory examination values including ΔHGB (g/L), ΔHCT, ΔPCT, and ΔCr (μmol/L) for PL and HLL groups was 19 ± 11.23/12 ± 15.42 (p = 0.012), 0.057 ± 0.034/0.038 ± 0.045 (0.009), 0.027 ± 0.034/0.026 ± 0.034 (0.702), and 3.07 ± 17.4/20.54 ± 65.93 (0.692), respectively. The postoperative hospitalization day was 8.94 ± 4.2 and 7.73 ± 2.75 (p = 0.015), respectively. As for the stone-free rate (SFR), the SFRs for PL and HLL were 48.15% (n = 39/81) and 59.09% (n = 13/22) (p = 0.363), respectively.

CONCLUSIONS

HLL showed a comparable advantage of not only decreased postoperative hemoglobin and hematocrit but also fewer postoperative hospitalization days. Based on the results of our retrospective study, for those Grade IV kidney stone patients who have a risk of bleeding before PCNL operation, HLL can be a considerable treatment option. Besides, in consideration of reducing human care cost, HLL which showed fewer hospitalization days, would be more welcome by patients.

Profile of metabolic and infectious stone-formers in a contemporary PCNL cohort

INTRODUCTION

To identify factors associated with stone composition in patients undergoing percutaneous nephrolithotomy (PCNL).

MATERIAL AND METHODS

A retrospective analysis of patients who underwent PCNL at two academic institutions between 2002 and 2014. Stone composition, stone characteristics based on non-contrast computer tomography (NCCT), patient demographics, and the S.T.O.N.E nephrolithometry scores were compared. Stones were characterized as either infection or metabolic. Metabolic stones were classified as calcium phosphate-containing and all others.

RESULTS

A total of 192 renal units underwent PCNL. Retrieved stones were found to be 75% (144) metabolic and 25% (48) infection by stone analysis. Of the metabolic stones, 51% (73) were phosphate-containing calculi. Overall, infection stones were found to have a significantly higher S.T.O.N.E nephrolithometry score than metabolic stones (9.2 versus 8.1, p < 0.001). Average Hounsfield units (HU) were significantly lower in infection stones (765 versus 899, p < 0.05). Sixty-three percent of patients with infection stones were female as compared to 46% of patients with metabolic stones. Patients with phosphate-containing stones in the metabolic group were significantly more likely to be female (56% versus 35%, p < 0.01), younger (mean 49 versus 60 years of age, p < 0.02), and have lower BMI's (30 versus 32, p < 0.02) compared with other metabolic stones.

CONCLUSIONS

Patient demographics including age, sex and BMI differ between patients with phosphate and non-phosphate containing metabolic stones. Higher S.T.O.N.E nephrolithometry scores were found in infection stones. These findings may serve as useful tools in the identification of stone compositions that are being seen more frequently in large and complicated stones undergoing PCNL.

[Etiopathogenic factors of the different types of urinary litiasis.]

In this review, we analyze the etiopathogenic principles of urinary lithiasis formation. In the kidney, calcifications that may cause renal lithiasis are produced as a consequence of processes that injury the urothelium at the papilla and Bellini's ducts. With the improvement of imaging techniques, mainly micro CT scan, it is possible to detect them and we may be able to anticipate to the formation of lithiasis. As we well know, there are different factors that influence the formation of the calculi depending on their composition. In calcium lithiasis it is key to review the modification of the categories of hypercalciuria, we currently distinguish two types instead of three, thanks to the fasting calcium/ creatinine ratio, differentiating absorptive hypercalciuria and fasting hypercalciuria. In the fasting hypercalciuria, it is important to emphasize the relationship between this factor and the loss of bone mineral density in patients with recurrent renal calcic lithiasis, so that in this kind of patients it is compulsory the study of bone metabolism by bone remodelling markers and bone densitometry. Regarding the other factors that participate in the formation of calcium lithiasis we should specially emphasize on hypercalciuria and its growing increase because of its relationship with obesity and metabolic syndrome, as well as hipocitraturia, present in an important percentage of patients and related in some cases with metabolic acidosis and osteopenia-osteoporosis too. In relation to uric acid lithiasis it should be highlighted that urinary pH is the most determinant factor and, therefore, its control and modifications would be paramount for prevention of this type of lithiasis. In the infectious lithiasis, the presence of germs that split urea is mandatory. They generate ammonia ions with the ability to injure the urothelium and to form magnesium ammonium phosphate lithiasis mainly. Regarding cystine lithiasis, rare, it was classically divided in three types and now passed to be classified in type A and B depending on the muted gene, and it is more useful to perform direct 24-hour urine measurement than screening tests which have low sensitivity. In general, we tried to give a comprehensive view of the various types of lithiasis emphasizing the most interesting clinical points for the urologist.

Is retrograde intrarenal surgery for the treatment of renal stones with diameters exceeding 2 cm still a hazard?

INTRODUCTION

Major kidney stones have traditionally been treated with percutaneous nephrolithotomy. However, retrograde intrarenal surgery (RIRS), which until a few years ago was considered inappropriate for this purpose, is becoming a viable, attractive alternative. The aim of the current study was to assess the efficacy and safety of RIRS combined with holmium laser lithotripsy for the treatment of stones > 2 cm in diameter in a large series of patients, reporting complications according to the Clavien-Dindo classification.

MATERIALS AND METHODS

By retrospective analysis, we identified a total of 162 patients who were affected by stones greater than 2 cm in diameter and who had undergone RIRS. We reviewed demographic and stone characteristics, intraoperative and postoperative outcomes, and complications.

RESULTS

The mean stone size was 2.7 cm +/- 0.6 cm. The primary, secondary, and tertiary stone-free rates were 66%, 80.9%, and 87.7%, respectively. The mean number of procedures per patient was 1.48. The complication rates according to the Clavien-Dindo classification were Clavien I in 20.4% of patients, Clavien II in 0%, Clavien III in 4.9%, Clavien IV in 0.6%, and Clavien V in 0%.

CONCLUSIONS

As an alternative to standard procedures for the treatment of renal calculi greater than 2 cm in diameter, RIRS is safe and effective, with a low complication rate.

[Renal stone disease: collaborative management between primary care and specialized physicians]

Nephrolithiasis is a highly prevalent pathology with a 10% lifetime risk in the Western population. Although it is often minimized and qualified as "idiopathic" significant comorbidities are frequently observed, e.g. the metabolic syndrome, type 2 diabetes mellitus, hypertension and bone fragility. Therefore nephrolithiasis can be regarded as a systemic disorder. A specialized diagnostic and therapeutic approach should be offered to such patients with active kidney stone disease in order to prevent stone recurrence and favor early diagnosis of said comorbidities.

Analysis and classification of heterogeneous kidney stones using laser-induced breakdown spectroscopy (LIBS)

Kidney stones were analyzed using laser-induced breakdown spectroscopy (LIBS), utilizing a high resolution multi-channel charge-coupled device (CCD) spectrometer and a nanosecond-pulse Nd : YAG laser. The kidney stones were also characterized using X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques for comparative analysis. It was found that the ratio of hydrogen (H) to carbon (C) was an important indicator of organic compounds such as uric acid. Advantages of LIBS, especially with regards to amount of sample required and sample preparation as well as the ability to carry out elemental analysis and classification of kidney stones simultaneously, over other analytical techniques such as XRD and XRF are discussed. The common minor elements detected in the kidney stones include P, S, Si, Ti, and Zn. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of broadband LIBS spectra were employed for classifying different types of kidney stones. The results are beneficial in understanding kidney stone formation processes, which can lead to preventive therapeutic strategies and treatment methods for urological patients.

Hyperspectral imaging based method for fast characterization of kidney stone types

The formation of kidney stones is a common and highly studied disease, which causes intense pain and presents a high recidivism. In order to find the causes of this problem, the characterization of the main compounds is of great importance. In this sense, the analysis of the composition and structure of the stone can give key information about the urine parameters during the crystal growth. But the usual methods employed are slow, analyst dependent and the information obtained is poor. In the present work, the near infrared (NIR)-hyperspectral imaging technique was used for the analysis of 215 samples of kidney stones, including the main types usually found and their mixtures. The NIR reflectance spectra of the analyzed stones showed significant differences that were used for their classification. To do so, a method was created by the use of artificial neural networks, which showed a probability higher than 90% for right classification of the stones. The promising results, robust methodology, and the fast analytical process, without the need of an expert assistance, lead to an easy implementation at the clinical laboratories, offering the urologist a rapid diagnosis that shall contribute to minimize urolithiasis recidivism.

Differentiation of human kidney stones induced by melamine and uric acid using surface desorption atmospheric pressure chemical ionization mass spectrometry

Clinically obtained human kidney stones of different pathogenesis were dissolved in acetic acid/methanol solutions and then rapidly analyzed by surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) without any desalination treatment. The mass spectral fingerprints of six groups of kidney stone samples were rapidly recorded in the mass range of m/z 50-400. A set of ten melamine-induced kidney stone samples and nine uric acid derived kidney stone samples were successfully differentiated from other groups by principal component analysis of SDAPCI-MS fingerprints upon positive-ion detection mode. In contrast, the mass spectra recorded using negative-ion detection mode did not give enough information to differentiate those stone samples. The results showed that in addition to the melamine, the chemical compounds enwrapped in the melamine-induced kidney stone samples differed from other kidney stone samples, providing useful hints for studying on the formation mechanisms of melamine-induced kidney stones. This study also provides useful information on establishing a MS-based platform for rapid analysis of the melamine-induced human kidney stones at molecular levels.

Type of renal calculi: variation with age and sex

The aim of this paper is to study the variations in the percentage of the different types of renal stones with age and sex. Renal calculi were classified according to their composition and structure. Stone formers were divided according to age and sex, and the percentage of each kind of calculi in the different considered age periods for men and women were determined. It was found that calcium oxalate dihydrate calculi decreased with age, but only in men. These calculi were also clearly predominant in men. Hydroxyapatite calculi decreased with age in both men and women, but they were predominant in women. Uric acid calculi increased with age in both men and women, but were predominant in men. Finally, it was found that calcium oxalate monohydrate unattached calculi increased with age in both men and women. As a main novelty, the study here presented demonstrates the importance of distinguishing between calcium oxalate monohydrate papillary stones and calcium oxalate monohydrate unattached stones, since the etiologic factors responsible for their origin must be clearly different.

CYSTINE: HELICAL COMPUTERIZED TOMOGRAPHY CHARACTERIZATION OF ROUGH AND SMOOTH CALCULI IN VITRO

PURPOSE

The classification of cystine stones into rough and smooth varieties has been suggested as an aid to choosing treatment for these difficult stones. Since the surface of stones is difficult to visualize preoperatively, we tested the hypothesis that the surface morphology of cystine stones correlates with their internal structure, as viewed by helical computerized tomography (CT).

MATERIALS AND METHODS

Cystine stones were examined visually and categorized into rough (15 stones) and smooth (16 stones) subpopulations of similar size. Each stone was scanned in a helical CT scanner (GE Quad Scanner) to assess radiological characteristics and to measure attenuation values. Scans were also performed using a microCT 20 high resolution laboratory scanner (Scanco Medical AG, Bassersdorf, Switzerland) at 34 microm voxel size and the percent of internal voids was determined.

RESULTS

Mean helical CT attenuation values +/- SD for rough stones were lower than for smooth stones (702 +/- 206 vs 921 +/- 51 HU, p <0.002) and the radiological appearance of rough stones suggested radiolucent voids. Internal voids in rough stones were confirmed using micro CT. Rough cystine stones contained a higher percent of internal voids (0.30% vs 0.06%, p <0.0001).

CONCLUSIONS

Rough cystine stones can be distinguished from smooth stones using helical CT in vitro, suggesting that it may be possible to distinguish these stones preoperatively. Since rough cystine stones have been reported to be susceptible to shock wave lithotripsy, the identification of this morphology of cystine stones in the patient using attenuation values and appearance on helical CT could be valuable for planning treatment.

Variability of renal stone fragility in shock wave lithotripsy

OBJECTIVES

To measure, in an in vitro study, the number of shock waves to complete comminution for 195 human stones, representing six major stone types. Not all renal calculi are easily broken with shock wave lithotripsy. Different types of stones are thought to have characteristic fragilities, and suggestions have been made in published reports of variation in the fragility within some types of stones, but few quantitative data are available.

METHODS

Kidney stones classified by their dominant mineral content were broken in an unmodified Dornier HM3 lithotripter or in a research lithotripter modeled after the HM3, and the number of shock waves was counted for each stone until all fragments passed through a sieve (3-mm-round or 2-mm-square holes).

RESULTS

The mean +/- SD number of shock waves to complete comminution was 400 +/- 333 per gram (n = 39) for uric acid; 965 +/- 900 per gram (n = 75) for calcium oxalate monohydrate; 1134 +/- 770 per gram (n = 21) for hydroxyapatite; 1138 +/- 746 per gram (n = 13) for struvite; 1681 +/- 1363 per gram (n = 23) for brushite; and 5937 +/- 6190 per gram (n = 24) for cystine. The variation for these natural stones (83% +/- 15% coefficient of variation) was greater than that for artificial (eg, gypsum-based) stones (17% +/- 8%).

CONCLUSIONS

The variability in stone fragility to shock waves is large, even within groups defined by mineral composition. Thus, knowing the major composition of a stone may not allow adequate prediction of its fragility in lithotripsy treatment. The variation in stone structure could underlie the variation in stone fragility within type, but testing of this hypothesis remains to be done.

Segmentation of renal calculi in ultrasound images

An algorithm proposed by Sridhar and Kumaravel is extended to include a framework for the detection of renal calculi. Calculi occur due to abnormal collection of certain chemicals like oxalate, phosphate and uric acid. These calculi can be present in the kidney, ureter or urinary bladder. Performance analysis is done to a set of five known algorithms using parameters such as success rate in calculi detection, border error metric and time. The framework is constructed by combining the best algorithm based on the performance analysis and a procedure to validate the detected calculi using the shadow it casts in ultrasound images. Ultrasound images of 37 patients are used for testing the algorithm. The detected calculi based on the framework match those determined by expert clinicians in more than 95% of the cases.

Simple classification of renal calculi closely related to their micromorphology and etiology

BACKGROUND

Classification of renal calculi with clear correlation with the main urinary etiological conditions has been previously established. However, such information is complex and difficult to adapt to clinical routine practice.

METHODS

A simple classification of renal calculi based on their structure and composition is proposed and applied to 2500 renal calculi to achieve the percentage of each category. The urines of 700 individuals chosen randomly have been analyzed and the results compared with those obtained with 51 healthy subjects.

RESULTS

12.9% calculi corresponded to calcium oxalate monohydrate papillary calculi, 16.4% to calcium oxalate monohydrate unattached calculi, 33.8% to calcium oxalate dihydrate calculi, 11.2% calcium oxalate dihydrate/hydroxyapatite mixed calculi, 7.1% hydroxyapatite calculi, 4.1% struvite calculi, 0.6% brushite calculi, 8.2% uric acid calculi, 2.6% calcium oxalate/uric acid mixed calculi, 1.1% cystine calculi and 1.9% various infrequent calculi. Based on the corresponding urinary analytical studies, each kind of calculus is related with the more frequently associated urinary alterations.

CONCLUSIONS

An important aspect of this classification is the possibility to establish, by means of the correct study of the calculus, some of the main possible etiologic factors closely related to its formation.

[Types of kidney calculi. Relationship with urinary biochemistry]

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.

When and how to evaluate a patient with nephrolithiasis

Nephrolithiasis is a common disorder that afflicts up to 12% of the population and continues to be a significant cause of patient injury. Evaluation of these patients should include the assessment of their comorbidities and underlying medical conditions. Patients who form stones can undergo a streamlined evaluation. A cause can be found in more than 90% of these patients. With medical treatment, stone-recurrence rates can be decreased by 85% for calcium oxalate stone formation, which affects a large proportion of patients. Introduction of nonspecific medical therapy in uncomplicated calcium stone disease may improve the quality of life for these patients and allow utilization a simple diagnostic protocol. This is in contrast to the previous recommendations of disease-specific therapy. Because patients without complications represent the majority of those who form stones, a simplified approach greatly reduces the cost of evaluation and treatment. Underlying medical conditions, however, require disease-specific therapy. The protocol represented here should aid physicians and patients in the approach to management of stone disease. The fasting calcium-load test is not required, and the entire evaluation can be performed in an ambulatory setting in two visits. Two 24-hour urine samples should be obtained on a random and restricted diet. Patients who form calcium stones can be subdivided into those who form hypercalciuric and normocalciuric stones. Patients who form normocalciuric stones are treated with conservative measures (increased fluid intake) and potassium and magnesium citrate. Patients who form hypercalciuric stones are treated with a combination of thiazides and potassium and magnesium citrate.

Classification of urinary stones by cluster analysis of ionic composition data

The cluster analysis technique is considered for classifying kidney stones based on data for nine chemical analysis parameters. A set of 214 stones is used, which has been previously classified using empirical classification rules into three stone types using the percentage concentrations of the urate, oxalate, and phosphate radicals. We investigate whether cluster analysis utilising data on all parameters leads to different classifications and explore the possibility of other effective classifiers. We also compare the performance of various clustering techniques, distance and similarity measures and data standardisation methods. Results indicate that inclusion of the additional six parameters does not improve the classification accuracy. Best matching with the empirical classification (6% error) is achieved using the average linkage (between groups) clustering method and the squared Eculidean distance measure without data standardisation. Excluding these three main radicals causes a 63% matching error. Cluster analysis results suggest that carbon ions alone provide a single classifier for the three stone types, giving a matching error of approximately 10% with the empirical classification.

Long-term follow-up after primary extracorporeal shockwave lithotripsy monotherapy of staghorn calculi: results after more than 6 years

OBJECTIVE

We retrospectively investigated 58 patients suffering from 60 staghorn calculi, who were treated with primary extracorporeal shockwave lithotripsy (ESWL) monotherapy, in order to determine long-term results and the fate of the residual stones.

MATERIAL AND METHODS

Mean follow-up was 72.4 months. There were 49 partial staghorn calculi (C4) and 11 complete C5 stones according to Rocco's classification. The mean number of ESWL sessions needed for disintegration was 3.6. The mean amount of shockwaves was 10,244. ESWL monotherapy alone was performed in 26 staghorn calculi (43.3%). In treating the other 34 staghorn calculi 56 auxiliary procedures were necessary.

RESULTS

At discharge 28.3% of the patients were free of stones. Fifty-five percent had small remnant particles (< 4 mm) and 16.7% had rest-fragments (> 4 mm). After a mean follow-up period of 72.4 months 36 patients were free of stones (60%). Twenty-four patients still have residual stones. The fragments in 2 patients did not change in size, in 14 patients fragments became bigger and 8 patients had a real recurrence (13.3%).

CONCLUSIONS

Primary ESWL monotherapy of staghorn calculi is justified because of the comparable results with open surgery and percutaneous nephrolithotomy (PCNL). Prognostic good factors are small stone mass with most of the stone mass in the upper and middle calices, the absence of dilatation and the absence of anatomical anomalies.

[Significance of "clinically insignificant residual fragments" (CIRF) after ESWL]

Almost 75% of all urinary calculi can be treated by extracorporeal shock wave lithotripsy (ESWL). In contrast to endoscopic and open-surgical procedures the patients are not immediately free of stones. The residual fragments after ESWL are called clinically insignificant residual fragments (CIRF), if the fragments are less than 5 mm in size and if there is the possibility of a spontaneous passage. But CIRF can cause ureteral obstruction. In addition, CIRF play an important role for the risk of stone growth and stone recurrence. The metaanalysis shows that it is not advisable to classify the CIRF only by their size. The morphological conditions of the urinary tract also have to be evaluated. Therefore, stone patients with CIRF after ESWL require a close follow-up and timely adjuvant therapy. All aspects mentioned lead to the conclusion to use the term "CIRF" with caution.

Patient evaluation. Laboratory and imaging studies

The evaluation of urolithiases, in terms of calculus detection and evaluation of the morphology and function of the kidneys, continues to be refined with advances in imaging technology. The most significant recent advance is use of helical or spiral CT scan for the accurate delineation of renal and ureteral calculi in the acute setting. This may provide an accurate, rapid, and cost-effective method of patient evaluation. The alternative approach is to use plain abdominal radiography to detect renal or ureteral calculi. Noncontrast-enhanced helical or spiral CT scanning has its greatest impact in patients with negative abdominal radiographs or in those patients with suspected urinary colic in whom renal but not ureteral calculi are seen. A supplemental intravenous urogram can be used, as appropriate, to evaluate renal function and degree of obstruction on both the involved and uninvolved side. Combined abdominal radiography and sonography may be used for calculus detection and demonstration of obstruction. Sonography is an operator-dependent technique requiring expertise, experience, and adequate imaging equipment for satisfactory results. Physiologic study of renal blood flow and urinary dynamics using Doppler techniques are possible, though considered to be in the realm of clinical investigation at this time. Sonography has a valuable role in the serial evaluation of chronic stone formers with a history of recurrent urinary infections related to obstruction or reflux. Radiography, fluoroscopy, and sonography are the imaging, methods used in ESWL treatment in preprocedure and postprocedure.

Study on calcium oxalate monohydrate renal uroliths. I. Qualitative properties

Shape, colour, surface features and external appearance were determined from 33 human uroliths composed predominantly of calcium oxalate monohydrate (COM). Based on these properties COM renal stones were classified into mulberry (M) and spheroid (S) type, each of which was further divided into two well defined subtypes, M1-fused globules, M2-loose globules, S1-corrugated surface and S2-even surface. This classification indicates that only specific combinations of external characteristics could occur on COM renal uroliths. No apparent correlation between the stone type and respective biochemical urinary data transpired from available information.

Kidney Stone Center of the Pacific. Summary of operations 1986 to 1993

The history and operational results in the six years since the Kidney Stone Center of the Pacific opened in 1986 are summarized and compared to the published literature, with particular attention to Hawaii's unique racial composition. We hope that the results will enable us to improve our management of stones in the future.

A study on calcium oxalate monohydrate renal uroliths. II. Fine inner structure

The inner fine structure of 30 human uroliths composed predominantly of calcium oxalate monohydrate was studied in detail. Each type of stone distinguished on the basis of qualitative parameters, viz. M1, M2, S1 and S2 (see Part I), exhibited a specific and characteristic inner structure different in several well-defined aspects from the other types. The inner structure suggests a sedimentary origin of the M1 type stone whereas the fixed particle origin of the M2, S1 and S2 stones, 3 types of core on which M2, S1 and S2 calculi developed were identified. The A type was represented by a void cavity with walls covered by an organic matter, the B type was formed by loosely arranged COM crystals and the C type was represented by a layer of an organic matter. Clinical observations lend support to the sedimentary origin of the M1 stones.

Study on calcium oxalate monohydrate renal uroliths. III. Composition and density

Density and content of mineral constituents were determined for 33 human calcium oxalate monohydrate (hereafter COM) uroliths whose external appearance and inner structure were described in part I and II respectively. Studied stones contained 0.13-0.42 wt.% of struvite, 0.68-4.12 wt.% of hydroxyapatite, 73-96 wt.% of COM and 3-10 wt.% of water unbound in a crystallohydrate 10 to 20 wt.% of calculus mass is not accounted for by chemical analysis. Density of COM calculi varying between 1.67 and 2.06 g cm-3 is not a function of any single stone parameter. Around 30% of stone volume is not occupied by crystalline components. The mulberry stones of sedimentary origin contained higher amount of organic matter than papillar and mulberry stones displaying site of attachment to epithelium.

A new system for descriptive classification of stones in the upper urinary tract

A descriptive classification is proposed to stratify upper urinary tract stones by their number, size and location. The system considers the minimal but most important factors regarding the choice of surgical treatment and its success. Its principle is adaptable to more complex staging systems already existing. Practical use of the system has shown it to reflect clinical events, and its simplicity offers an opportunity for compliance in routine clinical study. It facilitates easy computerized stratification of stones in the upper urinary tract.

[Bone involvement in idiopathic calcium lithiasis]

Bone involvement in idiopathic calcium nephrolithiasis is characterized by the following abnormalities: a) the bone density is decreased, the severity of bone loss being dependent upon the existence of hypercalciuria and upon the pathophysiology of this latter: it is inconsistent in the absence of hypercalciuria or when hypercalciuria is of the absorptive type I or II, whereas it is almost constant in fasting hypercalciuria without secondary hyperparathyroidism and constant and severe in the rare true renal hypercalciuria. b) The bone histology (which has been evaluated only in idiopathic hypercalciuric patients) mainly shows a defect in bone formation at the exception of the rare renal hypercalciuria. Osteoclastic hyperresorption is only seen in this latter type of hypercalciuria whereas in the other types of hypercalciuria only an increase of the total or inactive resorption surface is observed. This phenomenon is possibly explained only by a delayed refilling of the resorption lacunae secondary to the decreased bone formation. The osteoid thickness is either normal or decreased despite decrease in mineralization apposition rate which seems therefore to be secondary to the decreased bone formation. c) Symptomatic bone disease in hypercalciuric stone formers is exceptional and always related to a severe long term calcium restriction. d) The biochemical markers of bone resorption tend to be increased in idiopathic hypercalciuria. Hydroxyprolinuria is more often elevated than pyridinolinuria. However pyridinolinuria is negatively correlated to bone density. The contrast between the increase of these bone resorption markers and the usual normality of plasma PTH and of the osteoclastic resorptive surfaces, suggest the role of meat induced acid load which may favor inactive resorption by dissolution of bone buffers. A disturbed profile synthesis of cytokines which induce differentiation and proliferation of the osteoclasts and which modulate the osteoblastic proliferation and function (IL-1, IL-6, TNF-alpha, GM-CSF...) may play a role in the bone loss of calcium stone formers but further studies are necessary to precise its transient or permanent involvement in their bone disease. e) The decrease of bone formation may be explained by the suppressed PTH secretion which may be explained by hypercalcitriolemia. This excess of calcitriol synthesis may be secondary either to monocyte increased synthesis of IL-1 which stimulates the renal 1 alpha-hydroxylase by the mean of an increased PGE2 synthesis or to the relative hypophosphatemia of the calcium stone formers comparatively to healthy controls. Hypercalcitriolemia may originate from the activated monocyte itself. The decrease in bone formation may also be secondary to the action of monokines on the osteoblast differentiation and/or function.

Ambulatory evaluation of nephrolithiasis: an update of a 1980 protocol

Evaluations of 1,270 patients with recurrent nephrolithiasis in an outpatient setting were analyzed for the purpose of updating the classification of nephrolithiasis. All but 4% had abnormal urinary biochemistry that placed them into one or more of 20 etiologic categories. A single diagnosis was documented in 41.3% of patients. The remaining 58.7% had more than one diagnosis. Hypercalciuric calcium (Ca) nephrolithiasis, encountered in 60.9% of patients, comprised six variants--absorptive hypercalciuria Type I and II, renal hypercalciuria, primary hyperparathyroidism, and unclassified hypercalciuria (renal phosphate leak and fasting hypercalciuria). Hyperuricosuria Ca nephrolithiasis (HUCN) and gouty diathesis (GD) accounted for 35.8% and 10.0% of patients, respectively. Distinguishing features were hyperuricosuria and normal urinary pH in HUCN, and normal urinary uric acid and low urinary pH (< 5.5) in GD. Hyperoxaluric Ca nephrolithiasis, occurring in 8.1% of patients, was subdivided into enteric, primary, and dietary variants. Hypocitraturic Ca nephrolithiasis affected 28% of patients in its idiopathic variant. Many of these patients' problems were probably dietary in origin, while some could have had incomplete renal tubular acidosis. Hypocitraturia due to renal tubular acidosis or chronic diarrheal syndrome affected only 3.3% of patients. Hypomagnesiuric Ca nephrolithiasis, infection stones, and cystinuria were uncommon, accounting for 6.8%, 5.9%, and 0.9% of patients, respectively. The acquired problem of low urine volume (< 1 L/d) was found in 15.3% of patients. The remaining 3.5% of patients were difficult to classify despite the presence of abnormal urinary biochemistry.

[Staghorn nephrolithiasis]

The authors review the problem of staghorn nephrolithiasis (SN) basing on their experience in the disease diagnosis, treatment and prevention. Basing on the analysis of 2021 cases (1354 females and 667 males), the data on SN etiology and pathogenesis are provided. A complex of diagnostic procedures, an original classification, differentiated indications to various conservative or surgical treatments, trends in prevention of nephrolith reappearance, promising research approaches are outlined.

[Treatment of staghorn calculi on the basis of composition and structure]

Most staghorn calculi are infection stones composed of struvite and/or carbonate apatite. Sometimes, cystine, uric acid, whewellite and brushite stones also assume a staghorn configuration when located in the kidney. It is very important in stone crushing to know the composition and architecture of the stones. Struvite stones show a concentric laminal structure and are fragile because of wide interstices of crystals and rich organic matrix. These stones usually contain many bacterial colonies in the interstices of crystals and bacteria break out of the stones when they are crushed. Therefore, perioperative administration of antibiotics is necessary for prevention of bacteremia and sepsis. Whewellite stones and uric acid stones have a smooth surface and reveal compact radial and laminal structure especially in the peripheral layer. They are very hard and are refractory to crushing, and the fragments are large. Cystine stones show a compact radial monomineral texture and are very hard. The fragments made by crushing are large. Therefore, combination therapy of stone crushing and irrigation of alkali solution may be useful for treatment of cystine stones as well as uric acid stones. Calcium phosphate stones, hydroxyapatite or brushite stones, are rare and are formed in hyperparathyroidism, Cushing syndrome and renal tubular acidosis. Hydroxyapatite stones are rich in matrix and fragile. Brushite stones reveal radiate structure and are hard. There is no general method of treatment for staghorn calculi but we should select the most reasonable method including open surgery for each case taking into consideration the stone composition, predisposing factors and possibility of stone residue and recurrence.

The structure of large lamellar urinary stones. A quantitative chemical analytic study applying a new classification scheme

To study the structural composition of 61 renal and 9 vesical large lamellated non-infection urinary tract stones, samples from successive layers were quantitatively analyzed with standard chemical techniques, but with a new classification based on percentage composition of ions rather than compounds. The commonest pattern of composition (n = 41) was that of the lamellar stones of one stone type (uric acid, oxalate, or phosphate) and group (according to % of indicating ion), followed by bilamellar stones of different stone types (17) or of one stone type but different groups (8). The other stones were trilamellar (3) or quadrilamellar (1) of different stone types. In the 29 stones with lamellae of different type and/or group, the chemical composition of successive layers seemed to confirm the correlation between uric acid and oxalate, rather than phosphate, ions and between oxalate and both uric acid and phosphate ions. An influence on these correlations either positive or negative, may be the responsible factor for specifying the type and group of a forming stone or layer of a stone. The observed ionic correlations within the stones seem to support the choice of the oxalate ion, in the uric acid or phosphate stones, and both of the uric acid and phosphate ions, in the oxalate stones, as indicating ions for grouping in our proposed classification of urinary stones.

Staghorn calculi of the kidney: classification and therapy

Following the introduction of new techniques, the reclassification of staghorn calculi is indicated in order to establish the most suitable form of treatment. Of 269 patients with staghorn calculi treated over a 3-year period, 56% underwent extracorporeal shockwave lithotripsy (ESWL) monotherapy; 16% required open surgery and the remaining 28% underwent percutaneous nephrolithotripsy (PCNL) with ultrasound in association with ESWL. The latter group has been reviewed, taking into account invasiveness, results, complications and cost effectiveness. A combination of PCNL and ESWL was beneficial in patients in whom percutaneous access through a single tract removed more than 70% of the stone. As a result of these findings, the authors propose a revised classification of staghorn calculi.

[A new classification of reno-ureteral lithiasis]

The Authors suggest a change in their surgical classification of renal calculi to conform the description to the new techniques in the treatment of renal calculosis. Category "C" describes the morphology and topography of renal stones in five degrees (C1-C5); small letters "p, s, m, i" indicate the pelvis, superior, middle, inferior calyces; "n" and "a" symbolize stone having a size similar to or exceeding normal shaped renal cavities. "Cu" indicates ureteral calculi; small letters "l, i, p" indicate lumbar, iliac, pelvic ureteral stones. "N" describes the nature of the calculi. Category "E" stands for the excretory tract; "+" and "-" indicate the presence or absence of dilatation, the small letters "e, i" show the extra or intrarenal position of renal cavities; "no" and "o" indicate absence or presence of intrinsic obstruction of the excretory tract. "R" points out the number of surgical recurrences. Category "P" indicates the function of the parenchyma; numbers 1, 2, 3, refer to normal renal function, moderate or serious insufficiency. "U" stands for unique functional or anatomical kidney; "I" indicates the presence of infection.

Extracorporeal shock wave lithotripsy as monotherapy of staghorn renal calculi: 3 years of experience

From May 1985 to February 1988, 61 patients with renal staghorn calculi (41 with incomplete C4 and 20 with complete C5 lesions) underwent extracorporeal shock wave lithotripsy monotherapy. Of the patients 37 were treated without preoperative Double-J* stenting, while 24 underwent Double-J stenting before extracorporeal shock wave lithotripsy. Of the patients with incomplete staghorn calculi (C4) and a preoperative ureteral stent 85% were free of stones after 6 months in contrast to only 52.4% of those without a stent and 85.7% of those with infected C4 calculi who underwent preoperative stenting. Hospitalization decreased from 17.7 days in patients without a stent to 14.2 days after stenting, followed by the number of auxiliary procedures (nephrostomy, Zeiss loop and ureteroscopy) and postoperative complications. Complete staghorn calculi (C5) without a preoperative stent had the smallest success rate of stone elimination: only 43.7% of the patients were free of stones after 6 months with a rehospitalization rate of 62.5%. For incomplete staghorn renal calculi (C4) extracorporeal shock wave lithotripsy monotherapy with a preoperative Double-J stent is the noninvasive method that offers excellent stone elimination (85%), comparable to the results of percutaneous nephrolithotripsy (with or without complementary extracorporeal shock wave lithotripsy) and anatrophic nephrolithotomy.

The metabolic evaluation of patients with recurrent nephrolithiasis: a review of comprehensive and simplified approaches

The advent of percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy has definitely altered the way in which symptomatic renal calculi are approached. However, these new techniques should not affect the need for appropriate diagnostic evaluation and institution of medical treatment for the prevention of recurrent nephrolithiasis. A diagnostic evaluation should identify underlying physiological and environmental defects responsible for stone formation, as well as identify specific medical disorders that cause recurrent stone formation. With this information one then can construct an appropriate treatment program that will prevent the occurrence of additional calculi. Comprehensive metabolic protocols have evolved from tedious inpatient procedures to more convenient outpatient tests that can be performed in approximately 2 weeks. In addition, the advent of automated urinalysis packages has allowed many physicians access to reliable, sophisticated technology. Further dissemination of these simplified metabolic protocols will enable more accurate diagnosis of recurrent stone disease and, hopefully, permit the institution of appropriate medical therapy by a wider group of treating physicians.

Classification of patients subjected to extracorporeal shock wave lithotripsy

A simple system is described for classification of patients with urolithiasis treated with extracorporeal shock wave lithotripsy (ESWL). According to the size and number of concrements in each kidney the patients were subgrouped in six different ESWL-types (A-F). The main purpose was thereby to be able to discriminate between different stone situations regarding the need for resources and to evaluate the therapeutic results in an appropriate way. Of 709 patients treated with ESWL during the first year, 2% were of ESWL-type A, 46% of type B, 24% of type C, 16% of type D, 5% of type E, and 7% of type F. There was a good relationship between ESWL-type, number of shock waves and duration of the treatment session, number of ESWL-sessions, and duration of hospital stay. With knowledge of the ESWL-type distribution in a group of patients with urolithiasis this classification provides a basis for estimates of treatment capacity and required number of beds. With a weekly capacity of 24 treatments the required number of beds usually varied between 20 and 25. The hospital stay varied between 2 and 35 days, with the longest hospital stay recorded for patients belonging to ESWL-type E undergoing a combined procedure with percutaneous surgery, ESWL, and often irrigation with hemiacidrin. The presented system for classification might be a useful tool for planning, organization and assessment of renal stone treatment based on ESWL.

Predisposing factors and prevention of renal calculi

Over the last few years there have been marked advances in both the surgical and medical treatment of urinary stone disease. At present, we have expectations of decreasing the incidence of stone recurrence in a vast majority of patients with medical therapy alone. While there are still many patients who will continue to develop new stones, decreasing their rate of new stone formation will lessen the need for surgical intervention.

[Classification of staghorn calculus disease of the kidney based on 105 personal cases and a review of the literature]

The majority of staghorn calculi (branched calculi)--25 per cent bilateral--is mainly composed of calcium phosphates, in about 2/3 with varying fractions of Struvite. Pure Struvite stones are rare. Large fractions of Struvite form a soft concrement. Infection with urea splitting bacteria arises ascending, therefore predominantly in female kidneys, except for the first decennium. Staghorn calculi without Struvite (1/3 of our cases), show extremely large growth and sterile urine. Some Struvite stones have sterile urine or Struvite without urea splitting bacteria. The shape of branched calculi depends on the form of hilus renalis and the aggressiveness of the alkaline urine and the infection. Renal cirrhosis--almost always present--follows bacterial or abacterial obstruction, depending on the degree of vascular obliteration by reactive fibrosis of the intima, with or without pyonephrotic, xanthomatous necrosis, similar to renal tuberculosis. The so-called "large stone kidney" is obstructive, aseptic and lipomatous special form of staghorn calculus and cirrhosis. Stone formation and grade of cirrhosis may be determined by tomography.

New drug therapy for kidney stones: a review of cellulose sodium phosphate, acetohydroxamic acid, and potassium citrate

Kidney stones have an overall incidence of two to three percent in western countries. In many patients, the disease process is difficult to control and recurrence rates are high: 20 to 50 percent over the subsequent ten years. The pathogenesis and standard methods of treatment for the five major types of stones (i.e., calcium oxalate, struvite, calcium phosphate, uric acid, and cystine) are reviewed. Three new drugs are reviewed in the context of their roles in the selective treatment of kidney stones. Cellulose sodium phosphate (Calcibind) is a nonabsorbable ion-exchange resin with a limited indication for the treatment of calcium stones associated with absorptive hypercalciuria Type I. Acetohydroxamic acid (Lithostat) is an urease-inhibitor that is indicated as adjunctive therapy in patients with chronic urea-splitting urinary tract infections and struvite stones. Potassium citrate (Urocit) is an investigational agent that has clinical efficacy in patients with calcium oxalate and calcium phosphate stones who are hypocitraturic. In addition, potassium citrate is an alkalinizing agent that can be used in patients with uric acid stones.

Pathogenesis of renal calculi

Urolithiasis involving the upper urinary tract is a multifactorial disease that remains a significant health problem. A variety of intrinsic and extrinsic factors influence the incidence of disease in individuals and in all populations. At the level of the kidney, natural physicochemical processes result in crystalluria and the formation and growth of stones. Urinary supersaturation of some degree must be present but its significance may be altered by changes in urinary volume, pH, epitaxial relationships, and the presence or absence of naturally occurring inhibitors. A variety of environmental parameters acting through effects on the local urinary conditions determine which patients among a group of people inherently at risk will form stones. The above factors are considered herein with regard to the four major types of stone disease encountered today.