The challenge of cystine and struvite stone formers: clinical, metabolic and surgical assessment.

PURPOSE: To compare the clinical, metabolic, and calculi characteristics of cystine and struvite stone patients after percutaneous nephrolithotripsy (PCNL). MATERIAL AND METHODS: Between January/2006-July/2013, 11 cystine stone patients were treated in our clinic. Of those, 3 were excluded due to incomplete follow-up. Eight cystine stone patients (2 with bilateral disease; 10 renal units-RU) were considered for further analysis. A cohort of 8 struvite stone formers (10RU) was matched having the same age, gender, body mass index (BMI) and Guys stone score. Analyzed parameters comprised demographic data, serum/urinary metabolic evaluation and surgical outcomes. RESULTS: Both groups had 6 female patients. Groups were similar in regards to age, gender, BMI, stone burden, and serum creatinine (p=NS). All patients had PCNL as the first surgical treatment modality. Stone free rate (SFR) after the first PCNL tended to be lower (0%) in the cystine compared to the struvite group (40%)(p=0.08). Final SFR after secondary procedures increased to 70% in cystine and 80% in struvite patients (p=1.0); mean number of procedures to achieve stone free status was higher in the first group (3.57 vs. 2.0;p=0.028). Hypocitraturia was found in all patients, but struvite cases presented with lower mean urinary citrate levels (p=0.016). Other common abnormalities were elevated urinary pH (cystine 75% and struvite 62.5%;p=1.0) and low urinary volume (62.5%,37.5%;p=0.63). CONCLUSION: Multiple interventions and suboptimal stone free rates are trait of the significant stone burden of struvite and cystine patients. Underlying metabolic abnormalities characterized by increased urinary pH, hypocitraturia and low urinary volume are often encountered in both populations.

Current management of antenatal hydronephrosis.

The strategy for the management of children with urinary tract anomalies has changed considerably as a result of the development of ultrasound equipment and techniques that allow for detailed fetal evaluation. Hydronephrosis is the most common urogenital anomaly detected, suggesting that an obstructive process may be potentially present. The goal of postnatal management is to identify and treat those patients whose renal function is at risk, while leaving alone the high percentage of patients who are at no risk of renal damage. This management involves a spectrum of radiological, medical, and surgical interventions for diagnosis, surveillance, and treatment. In this article, we review our current understanding of the natural history of antenatal hydronephrosis and its management.

Low-intensity shockwave therapy for erectile dysfunction in kidney transplant recipients. A prospective, randomized, double blinded, sham-controlled study with evaluation by penile Doppler ultrasonography.

OBJECTIVES: To study the efficacy of Low intensity Extracorporeal Shockwave Therapy (Li- ESWT) for the treatment of erectile dysfunction (ED) in kidney transplanted men. METHODS: Twenty men (mean age = 53.7 years) were selected. This was a double-blinded, prospective, randomized, sham-controlled trial. The ESWT protocol was based in a 2 treatment sessions per week for 3 weeks. The sham treatment was performed using the same device replacing the effective probe for one that emits zero energy. Baseline and follow-up assessment was performed with International Index of Erectile Function Questionnaire (IIEF) score and Erection Hardness Score (EHS) after 1, 4 and 12 months. Penile Doppler was performed before and after treatment. RESULTS: A total of 20 patients were recruited, 10 patients in each group. Baseline scores were similar. The mean EHS in after 1 month were 2.5 ± 0.85 (Li-EWST) and 2.4 ± 0.7 (Sham therapy), p = 0.724 . After 4 months it was 2.4 ± 0.7 and 2.6 ± 0.84, p = 0,0004 (between the moments) . The baseline IIEF score was 14.9 ± 3(Sham Theraphy) and 10.9 ± 5.1 (Li-EWST). The mean IIEF score after 1 month was 15.6 ± 6.1 (Li-EWST) and 16.6 ± 5.4 (Sham therapy). The mean IIEF score after 4 months was 17.2 ± 5.7 (Li-EWST) and 16.5 ± 5 (Sham therapy), p < 0.0001 (between the moments). IIEF score improvement was higher than 5 in 70% (ranged from 0-10) and in 10% (ranged from 1-14) in Li-ESWT and Sham groups, respectively. The mean change in IIEF score after 12 months was 4.8 in Li-ESWT group .Penile Doppler parameters were similar between groups and did not present improvements. CONCLUSIONS: Li-ESWT is a treatment with clinical efficacy. Despite evidences suggesting neoagiogenesis, our short protocol had no impact in penile Doppler parameters.

Predicting urinary stone composition based on single-energy noncontrast computed tomography: the challenge of cystine.

OBJECTIVE: To study several measurements from a single-energy noncontrast computed tomography (NCCT) that may distinguish calcium oxalate, uric acid, and cystine stones. METHODS: Patients with pure urinary stones who had at least 1 single-energy NCCT before the stone composition analysis from January 2008 to December 2012 were enrolled in this study. The analyzed data comprised stone size, volume, core Hounsfield unit (HU), periphery HU, absolute and relative HU differences between core and periphery, and HU density. After these measurements, an NCCT bone window was subjectively evaluated to study the homogeneity of each stone from core to periphery. The Spearman correlation test was used to determine the correlation between HU values and stone size and volume for each group. RESULTS: A total of 113 patients were found with pure urinary stones who also had a corresponding NCCT. There were 36, 47, and 30 patients in the calcium oxalate, uric acid, and cystine groups, respectively. The core HU, periphery HU, absolute and relative HU differences, and HU density were significantly different among the 3 groups (P<.001). Stone size and volume had a positive correlation with core and periphery HUs only for calcium oxalate and cystine stones. The subjective evaluation of the urinary calculi revealed a different pattern for each stone composition. CONCLUSION: Single-energy NCCT may predict calcium oxalate stones with a high degree of accuracy. There is an overlap in radiographic profiles of cystine and uric acid stones, making a definitive differentiation more challenging.

The challenge of cystine and struvite stone formers: clinical, metabolic and surgical assessment

ABSTRACT Purpose: To compare the clinical, metabolic, and calculi characteristics of cystine and struvite stone patients after percutaneous nephrolithotripsy (PCNL). Material and Methods: Between January/2006-July/2013, 11 cystine stone patients were treated in our clinic. Of those, 3 were excluded due to incomplete follow-up. Eight cystine stone patients (2 with bilateral disease; 10 renal units-RU) were considered for further analysis. A cohort of 8 struvite stone formers (10RU) was matched having the same age, gender, body mass index (BMI) and Guys stone score. Analyzed parameters comprised demographic data, serum/urinary metabolic evaluation and surgical outcomes. Results: Both groups had 6 female patients. Groups were similar in regards to age, gender, BMI, stone burden, and serum creatinine (p=NS). All patients had PCNL as the first surgical treatment modality. Stone free rate (SFR) after the first PCNL tended to be lower (0%) in the cystine compared to the struvite group (40%)(p=0.08). Final SFR after secondary procedures increased to 70% in cystine and 80% in struvite patients (p=1.0); mean number of procedures to achieve stone free status was higher in the first group (3.57 vs. 2.0;p=0.028). Hypocitraturia was found in all patients, but struvite cases presented with lower mean urinary citrate levels (p=0.016). Other common abnormalities were elevated urinary pH (cystine 75% and struvite 62.5%;p=1.0) and low urinary volume (62.5%,37.5%;p=0.63). Conclusion: Multiple interventions and suboptimal stone free rates are trait of the significant stone burden of struvite and cystine patients. Underlying metabolic abnormalities characterized by increased urinary pH, hypocitraturia and low urinary volume are often encountered in both populations.