Evaluation of the Effects of Relationships Between Main Spatial Lower Pole Calyceal Anatomic Factors on the Success of Shock-Wave Lithotripsy in Patients with Lower Pole Kidney Stones

doi:10.1016/j.urology.2007.11.052

Urology

Volume 71, Issue 5, May 2008, Pages 801-805

https://doi.org/10.1016/j.urology.2007.11.052 Get rights and content

Objectives

To evaluate the effects of lower pole calyceal anatomy on lower pole stone clearance after shock-wave lithotripsy (SWL).

Methods

A total of 133 patients who had single lower pole radio-opaque stones treated with SWL alone and who became stone-free or had clinically insignificant residual fragments (CIRF) were included in the study. Pre–shock-wave lithotripsy intravenous urograms were used to determine the lower pole infundibular width and length, lower pole infundibulopelvic (LPIP) angle, caliceal pelvic height (CPH), and lower infundibular length-to-width ratio. In addition, to evaluate the relationship between LPIP and CPH, a more simple alternative measurement instead of LPIP angle, called the parenchyma-to-ureter distance (PUD), was suggested. The correlation between LPIP and PUD was then examined, and a good correlation was found between these values (P <0.000, r = 0.64). The PUD/CPH ratio was also calculated.

Results

The stone-free rate was 62%. According to the cutoff points, the lower infundibular length-to-width ratio and PUD/CPH ratio were different in the stone-free and CIRF groups by univariate analysis but not by multivariate analysis.

Conclusions

None of the anatomic factors had a statistically significant effect in predicting the success of SWL in patients with lower pole stones. Nevertheless, evaluation of relationships between lower pole anatomic factors may offer some help in reaching a more accurate interpretation of lower pole stone clearance after SWL.

Section snippets

Patients

A total of 133 patients (83 male, 50 female; mean age 45.38 years; age range 16 to 75 years) with single lower pole radio-opaque stones detected on intravenous urography, who were treated with SWL alone using the Lithostar lithotriptor (Siemens Medical Systems, Erlangen, Germany) and who became stone free (n = 82) or had clinically insignificant residual fragments (CIRF) (a total diameter of 3 mm or less; n = 51), were evaluated in a retrospective review.

The clinical data of the patients

Results

Of 133 patients, 82 were stone free, for an overall stone clearance rate of 62%. The overall mean and median stone diameters were 11.75 ± 8.12 mm and 10 mm, respectively (range 3 to 29 mm). There was no difference in age, gender, degree of laterality of the stone within the kidneys, stone size, average number of shock waves per procedure, or kilovolts in the stone-free and CIRF groups. The mean stone diameters were 11.07 mm in the stone-free group and 12.8 mm in the CIRF group (P >0.05). The

Comment

Several previous studies confirmed that the success rate after extracorporeal SWL for lower caliceal calculi was adversely affected by increased stone size.1, 3, 8, 13 However, stone size was not found to have a statistically significant effect on the clearance of fragments in some of the studies, especially those in which only patients with stone diameter less than 20 mm were included.4, 6, 7, 12 We also think that with increasing diameter (greater than 2 cm), clearance might be adversely

Conclusions

The findings of the present study emphasize that none of the anatomic factors of the lower pole calyceal system had a statistically significant effect on predicting the success of SWL in patients with lower pole stones. Nevertheless, evaluation of relationships between lower pole anatomic factors may offer some help in reaching a more accurate interpretation of lower pole stone clearance after SWL.

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La litiasis urinaria representa una patología importante en la práctica urológica y requiere de un abordaje multidisciplinario. Su incidencia es del 10%, afecta a un grupo etario extenso, con factores que pueden influir en su aumento en determinados lugares.
Su diagnóstico aparece como hallazgo en controles rutinarios de salud o a través del sindrome de cólico renal, cuadro característico y de consulta frecuente en los servicios de urgencia. Su etiología no está del todo definida, siendo las hipótesis más aceptadas, las alteraciones excretoras del riñón sumada a factores ambientales y hábitos. El estudio incluye exámenes de laboratorio para descartar complicaciones como infecciones e insuficiencia renal. Las imágenes determinan el volumen de la litiasis, su ubicación y densidad, para decidir de qué manera resolver el caso, ya sea de manera espontánea o activa mediante distintos tipos de intervenciones quirúrgicas.
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En niños, la incidencia de litiasis urinaria es menor que en adultos, sin embargo, las consecuencias de esta enfermedad pueden ser desastrosas. La etiología es fuertemente asociada a factores genéticos. Actualmente los tratamientos quirúrgicos son similares a los practicados en pacientes adultos.
Urinary stones represent an important pathology in urological practice and requires a multidisciplinary approach. Its incidence is close to 10%, affecting a wide range of age groups, with several factors that can influence its incidence in certain places. The stones can be diagnosed as a radiologic finding in routine health checks or during an episode of renal colic, a frequent consultation in emergency services. Its etiology is not completely understood. The most accepted hypothesis involves excretory alterations of the kidney added to environmental factors and habits. The study of patients with urinary stones includes laboratory tests that aim at ruling out complications such as infections and renal insufficiency. The imagenology intends to determine the volume of stones, its location and density to help to decide how to resolve the case, either spontaneously or actively through different types of surgical interventions. Currently, non-enhanced computed tomography is considered the gold standard for diagnosing urinary stones. The treatments are proposed according to the different clinical situations: medical management of renal colic and expulsive therapy for spontaneous resolution of the symptoms; surgical management, where the most frequent techniques are rigid or flexible endoscopic ureterolitectomy extracorporeal shock-wave lithotripsy (ESWL), percutaneous nephrolitectomy (PNL), and finally the etiological study of urinary stones and preventive measures. In pediatric patients, the incidence of urinary lithiasis is lower than in adults, however, the consequences of this disease can be disastrous. The etiology is strongly associated with genetic factors. Currently, the surgical treatments are similar to those practiced in adult patients.
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Citation Excerpt :
Similar factors are important for planning ESWL. Lower calyceal stones tend to be less responsive to ESWL.53,54 This is further exacerbated in the setting of unfavorable lower pole morphology (eg, long lower pole calyces with narrow infundibula).49,54
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Citation Excerpt :
Fifty-nine percent of patients required one to two sessions while the remaining 41% >2 sessions. Sahinkanat et al. in their series reported one to two sessions in 72.9% patients, remaining 27.1% required >2 sessions with mean of 1.93 sessions [15]. Stone sizes were smaller (mean 1.17 cm) in above series justifying more treatment sessions in our patients.
To determine the role of the lower pole infundibular parameters as predictors of stone clearance following extracorporeal shock wave lithotripsy (ESWL).
Between March 2001 and February 2004, 243 renal units in 239 patients with isolated lower calyceal stones were treated by ESWL. Stone-free status was assessed after 3 months by plain X-ray abdomen and a kidney ultrasound scan. Persistent stone fragments ≥6 months after the completion of treatment was defined as residual stone. Radiogaphic parameters were obtained from intravenous urography (IVU). SPSS version 15.0 was utilized for all statistical analysis.
The median age of all patients was 38 years (range: 20–70 years). The male to female ratio was 2.1:1.
The mean stone size was 1.3 ± 0.7 cm. Overall, 144 renal units (60.9%) had undergone one or two sessions of ESWL, 43 (17.7%) 3, while 46 (18.9%) ≥4 sessions, with mean of 2.1 sessions.
Stone-free rates differed significantly between favorable and unfavorable infundibular length (IL), and infundibular width (IW) (p value = 0.01, p = 0.0001, respectively). Infundibulopelvic (IP) angle had no statistically significant effect on stone-free rate (p = 0.1).
The effect of stone size on stone-free rate in two groups revealed better overall results in favorable anatomy group than in unfavorable group in stone sizes, 0.5–1.0 cm, 1.1–1.5 cm, 1.6–2 cm and 2.1–2.5 cm (76.7%, 87.5%, 100%, and 56.2% vs. 41.1%, 55.5%, 66.6%, and 50%; p = 0.04, 0.10, 0.10, 0.80, respectively).
This study shows that lower infundibular length and width are significant anatomical factors in determining stone clearance following ESWL treatment of lower calyceal stones and these should be assessed before planning the treatment for lower calyceal stones.
A Prospective Randomized Controlled Trial of the Efficacy of External Physical Vibration Lithecbole after Extracorporeal Shock Wave Lithotripsy for a Lower Pole Renal Stone Less Than 2 cm
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We evaluate the efficacy and safety of external physical vibration lithecbole in improving the clearance rates of lower pole renal stones after shock wave lithotripsy.
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Endourology/MISEvaluation of the Effects of Relationships Between Main Spatial Lower Pole Calyceal Anatomic Factors on the Success of Shock-Wave Lithotripsy in Patients with Lower Pole Kidney Stones

Objectives

Methods

Results

Conclusions

Section snippets

Patients

Results

Comment

Conclusions

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

J Urol

Endourology/MIS
Evaluation of the Effects of Relationships Between Main Spatial Lower Pole Calyceal Anatomic Factors on the Success of Shock-Wave Lithotripsy in Patients with Lower Pole Kidney Stones