Crossed renal ectopia: A case report and review of the literature

Rarely occurring at birth, crossed renal ectopia is an abnormality in which both kidneys occupy the same side of the body while one ureter - its length based on kidney location - traverses across midline to graft into opposite-side bladder. McDonald and McClellan classified renal ectopia into 4 types. Solitary crossed renal ectopia (SCRE) is an extremely uncommon abnormality of the urinary system. To date, only 35 instances have been documented in published literature. Typically, these cases are detected by chance during patient assessments for related issues such as genitourinary, cardiovascular, hematological or vertebral abnormalities.

Une Liaison Dangereuse: Spontaneous Pyeloduodenal Fistula

We describe the case of a 76-year-old woman with a spontaneous nephroduodenal fistula. The patient was initially evaluated for gastrointestinal and urinary symptoms associated with fever and anemia, after which she was admitted with the diagnosis of right chronic pyelonephritis, hydronephrosis, and renal lithiasis. The fistula was diagnosed incidentally by percutaneous pyelography during a right nephrostomy and was later confirmed with an abdominal CT scan. A multidisciplinary decision was made to surgically treat the fistula (right nephrectomy plus duodenal repair); the surgery had a short-term positive outcome. We report a systematic review of the literature related to spontaneous pyeloduodenal fistulæ and their treatments.

Role of claudins in idiopathic hypercalciuria and renal lithiasis

Paracellular transport in the kidney is mediated by a family of proteins located in the tight junctions called claudins which confers its ionic selectivity. Claudin-2 is highly expressed in the proximal tubule and descending limb of Henle and mediate paracellular reabsorption of sodium and calcium cations. In the thick ascending limb of Henle (TALH) calcium is reabsorbed by a paracellular channel formed by Claudin-16 and-19. Claudin-16 mediates cationic permeability while Claudin-19 increases the cationic selectivity of Claudin-16 by blocking anionic permeability. On the other hand, Claudin 14, that is also located in TALH, inhibits the paracellular permeability of Claudin-16 to calcium. Recent wide genomic association analysis studies have detected four common synonymous variants (genetic polymorphisms of a single nucleotide, SNPs) at the locus of Claudin-14 gene that were significantly associated with the presence of renal lithiasis. Another study of wide genomic association and nephrolithiasis was carried out in the general population but including chromosome X, where claudin-2 gene is located. They detected nine SNPs that had a significant association with renal lithiasis risk. A greater knowledge of the paracellular pathway controlled by claudins and its regulation will allow us to develop future new treatments for idiopathic hypercalciuria and renal lithiasis.

Safety of megadose of vitamin D in patients with nephrolithiasis

OBJECTIVE

This article describes two patients with renal lithiasis who received a megadose of 25-hydroxy vitamin D (25[OH]D) and had a good outcome.

METHODS

The first case reports a 74-year-old man with a long-term history of renal lithiasis and about four episodes of renal crisis. He was treated once with extracorporeal shock wave lithotripsy. He also had a history of dyslipidemia, myocardial infarction, and stroke. Laboratory tests demonstrated 25(OH)D of 28 ng/mL (normal range (nr): >30 ng/mL), normal lipid levels, creatinine of 1.1 mg/dL, and homocysteine of 26.6 mcmol/L (nr: 5-15 mcmol/L); parathyroid hormone (PTH) was high at 67.3 pg/mL (nr: 10-65 pg/mL), serum total calcium was 8.6 mg/dL, 24-h urinary calcium was 139 mg/d (normal range 100-300 mg/d), and urinary sediment was normal. He received 50 000 IU per week of vitamin D for 3 mo, and 25(OH)D increased to 36.6 ng/mL. Urinary calcium was 142 mg/d, PTH was 46.7 pg/mL, and serum calcium was 9.6 mg/dL. No renal crisis was perceived. He asked for an alternative form of medication since he usually would forget to take drugs. Vitamin D in a single dose of 600 000 IU intramuscular was prescribed. He was asked to increase water intake to 2 to 3 L/d. After 3 mo his 25(OH)D was 75.0 ng/mL, serum calcium was 9.2 mg/dL, urinary calcium was 148 mg/d, and PTH was 38.7 pg/mL. He had no episodes of lithiasis renal crisis. Folic acid and methylcobalamin were added, and homocysteine normalized. At follow-up 3 y later, the patient was asymptomatic, cardiologic evaluation was stable without any other renal lithiasis crises, 25(OH)D continued to be normal at 62 ng/mL, and he received a megadose of vitamin D every 6 mo. Renal ultrasound revealed only microlithiasis. The second case reports a 52-year-old man with a long-term history of renal lithiasis experienced since he was 30 y old, with three renal crisis episodes. He was treated with an extracorporeal shock wave three times. Laboratory tests demonstrated 25(OH)D 18 ng/mL, normal biochemistry, total serum calcium of 10.2 mg/dL, 24-h urinary calcium of 154 mg/d, and normal urinary sediment. He received 50 000 IU per week of 25(OH)D for 3 mo, and 25(OH)D increased to 40.3 ng/mL. Urinary calcium was 167 mg/d, PTH was 35.3 pg/mL, and serum calcium was 10.1 mg/dL. No renal crisis was perceived. He asked for an alternative form of medication, and vitamin D in a single dose of 600 000 IU intramuscular was prescribed. He was asked to increase water intake to 2 to 3 L/d. After 3 mo, his 25(OH)D was 82.0 ng/mL, serum calcium was 9.6 mg/dL, urinary calcium was 175 mg/d, and PTH was 35.3 pg/mL. The renal ultrasound was unchanged. He had no episodes of lithiasis renal crisis. At follow-up 4 y later, the patient was asymptomatic without any other renal lithiasis crises, a renal ultrasound revealed a reduction of calculi size to microlithiasis, 25(OH)D continues normal, and he received a megadose of this vitamin every 4 mo.

CONCLUSION

To the best of our knowledge, this is the first description of a megadose of vitamin D used in patients with nephrolithiasis. Furthermore, this shows the safety of this strategy in patients without hypercalciuria.

[Usefulness of laser Holmium Lumenis Pulse 120 H® in the treatment of renal lithiasis through RIRS: Preliminary experience.]

INTRODUCTION

The Holmium laser is the most used energy source in flexible ureterrenoscopy (URSf). The Lumenis Pulse 120H® laser has a higher system energy, a higher energy per pulse and a higher repetition frequency in relation to other types of lasers, which offers advantages in the treatment of lithiasis.

OBJECTIVE

To analyze the results that we have obtained with the use of the Lumenis Pulse120H® laser in patients treated by intrarenal retrograde surgery (RIRS). As secondary objectives there are: the study of the demographic variables of the patients, the characteristics of the stones and the complications associated with the procedure.

MATERIAL AND METHODS

An observational, retrospective study of the first 26 patients treated by RIRS and Lumenis Pulse 120H® laser has been performed in our Service between August 2018 and February 2019. The size of the lithiasis was measured on the simple radiography and the CT, in addition, the volume of the lithiasis was calculated. For the realization of RIRS, 8.5Fr digital flexible ureterorenoscope (Olympus®) and the Holmium Lumenis 120H® laser with 200 micron laser fibers from Lumenis® were used. Statistical analysis was performed with the SPSSv21 system.

RESULTS

A total of 26 patients with renal lithiasis have been analyzed. The median age was 55.15 years (40.67-67.05). 57.7% of the patients had prior surgical treatment of lithiasis. Thirteen patients presented the litiasis in the renal pelvis, ten in the Upper Calicial Group (GCS), fifteen in the Middle Calicial Group (GCM) and eighteen in the Lower Calicial Group (GCI). The median of the lithiasic volume was 1826.41 mm3. Our overall success rate was 80.8% (100% success in lithiasis less than 2 cm and 85.7% in lithiasis between 2-3 cm). Five patients presented complications, of which 4 were ClavienII and 1 Clavien IIIb. No significant results were found between the lithiasic size and the presence of complications (p = 0.128).

CONCLUSIONS

The use of the Lumenis Pulse 120H®laser is an useful tool for the treatment of kidney stones by RIRS, due to his efficiency in the fragmentation and dusting, taking into account that very large lithiasic masses require, in a high percentage of cases, more than one treatment session.

Comparative analysis of direct and indirect costs of two minimally invasive techniques for the treatment of renal/ureteral calculi smaller than 2 cm

OBJECTIVE

To perform a comparative analysis of indirect and direct costs of two minimally invasive techniques (extracorporeal shock wave lithotripsy (ESWL) vs. ureteroscopy with holmium laser (URS/RIRS)) for the treatment of renal/ureteral calculi smaller than 2 cm.

MATERIAL AND METHODS

Prospective, comparative, non-randomized study of 84 patients treated for kidney stones smaller than 2 cm between January and December 2016. Of these, 38 (45.67%) were treated with ESWL (18 renal lithiasis and 20 ureteral lithiasis) and 46 (54.32%) with URS/RIRS (22 renal lithiasis and 24 ureteral lithiasis). A total of 19 (41.3%) patients in the URS/RIRS group and 15 (39.5%) patients in the ESWL group were actively working before treatment. The variables analyzed were sex, age, number and size of lithiasis, time (days) off from work due to treatment, estimate of indirect cost due to labor productivity loss and direct treatment costs including follow-up (total number of procedures, ancillary care, visits and diagnostic tests). The 2015 Wage Structure Survey (INE) was used to estimate the indirect cost. In addition, the «Work Productivity and Activity Impairment» (WPAI) questionnaire was also used to determine the level of perceived productivity loss.

RESULTS

The mean number of sessions until lithiasis resolution was achieved was 2.57 for the ESWL group and 1.04 for the URS. The mean number of days off from work in the URS group was 7.16 days and 3.18 (p = 0.034) in the ESWL group. The total indirect costs resulting from productivity loss were EUR 621.55 and EUR 276.05 for the URS and ESWL, respectively. Direct costs in the ESWL group were EUR 1,382.9 and EUR 2,317.71 in the URS group. The level of work impairment perceived by patients undergoing URS was 18.88% and 21.33% in the ESWL group. The degree of impairment for performing activities of daily living was 24.44% in the URS and 15% in ESWL.

CONCLUSIONS

The ESWL technique requires a higher number of sessions for the resolution of kidney stones under 2 cm, but it has a lower impact on total costs and on the perceived degree of affectation.

[Treatment of uretero-renal stones with shock wave lithotripsy. Results and complications with the dornier gemini emse 220f-XXP.]

OBJECTIVES

Extracorporeal shock wave lithotripsy is a minimally invasive therapeutic option for the treatment of renal-ureteral lithiasis. The aim of this study was to analyze the results and complications of shock wave extracorporeal lithotripsy treatment with the Dornier Gemini® Generator EMSE 220f-XXP device in patients with renal and ureteral lithiasis.

MATERIAL AND METHODS

Retrospective study including 377 patients with renal or ureteral lithiasis with indication for treatment with extracorporeal shock wave lithotripsy. The following variables were analyzed, age, sex, body mass index, lithiasis size, lithiasis location, presence of urinary diversion, number of lithotripsy sessions, number of shock waves, fluoroscopy time, wave energy, applied focal energy coefficient, efficiency coefficient, lithiasic fragmentation, lithiasic clearance, residual lithiasis, presence of lithiasis and complications. The results were analyzed with SPSS 17.0 considering statistical significance p≤0.05.

RESULTS

Of the 377 patients, 213 were men and 164 women, with a mean age of 51.28 ± 12.77 years. The mean size of the stones in maximum diameter was 11.77 ± 6.13 mm. Lithiasis fragmentation occurred in 81.9% of cases, with a percentage of residual lithiasis after the first session of 58.7% and a total or partial expulsion rate of lithiasis fragments of 68.3%, with global success at the end of sessions of lithotripsy of 69.8%. The overall Efficiency Ratio was 0.42, higher in upper calyx 0.51 and lower in medium calyx 0.35, with significant differences (p<0.05). The only differences were found in relation to the success of lithotripsy treatment (75% versus 64.6%, p=0.02), according to lithiasis size (≤10 mm maximum diameter in comparison to >10 mm). In patients with a DJ catheter there is a higher percentage of residual lithiasis (p=0.006).

CONCLUSIONS

Treatment with extracorporeal lithotripsy in small lithiasis and in well-selected patients obtains good results with a low rate of complications regardless of sex and body mass index.

Reassessing the Safety Profile of Lesinurad in Combination with Xanthine Oxidase Inhibitor Therapy

INTRODUCTION

The rate of adverse renal events has been shown to be higher in patients treated with lesinurad plus a xanthine-oxidase inhibitor (XOI) than in patients treated only with a XOI. We reassessed the risks for various adverse renal events from a different perspective and devised a hypothesis to explain the results.

METHODS

We used data from phase 3 trials that were publicly available from the full prescribing information document and estimated the relative risk and the number needed to treat for increased serum creatinine (sCri), renal failure, and renal lithiasis. We examined these risks for each treatment group and the risks stratified by estimated glomerular filtration rate (eGFR).

RESULTS

Overall, the relative risk for sCri was > 1.0 with the 400 mg/day dose of lesinurad and higher with the 200 mg/day dose, but it was < 1.0 for both lithiasis and renal failure with the 200 mg/day dose. The relative risk was only statistically significant for sCri with the highest dose of lesinurad. When results stratified by eGFR were considered, the rates of adverse events increased with declining renal function, but the relative risks decreased in parallel, as the rate of adverse events increased much more in the placebo arm than in the active arm (200 mg/day dose). Indeed, the relative risk was only significant for the highest dose of lesinurad in patients with normal eGFR.

CONCLUSION

The rate of sCri events was higher in patients treated with both lesinurad and a XOI rather than a XOI alone. This rate was found to increase with decreasing eGFR, but as it does in for both active and placebo arms the relative risk is not different from that observed in the placebo arms in the labeled 200 mg/day dose. This may be explained by pathophysiological changes that develop in chronic kidney disease.

Is emergency percutaneous antegrade drainage of the upper urinary tract useful for future percutaneous nephrolithotomy access?

Purpose

To compare percutaneous nephrolithotomy (PCNL) operations between patients with a preoperative nephrostomy tube and patients that the renal access was obtained at the time of the surgery.

Materials and Methods

We retrospectively evaluated PCNL cases. Patients were divided into two groups. Group 1 – a non-nephrostomy tube (percutaneous nephrostomy, PCN) group and Group 2 – patients with a PCN placed before the procedure. All preoperatively placed PCN's were performed in emergency situations by interventional radiologists (IR). Complications were classified according to the Clavien-Dindo classification. We compared stone characteristics, operation time, complications, efficacy and PCN usability at surgery.

Results

Five hundred twenty-seven patients who were submitted to PCNL for renal stones were included in the study. In 73 patients (13.9%) the PCNs were placed before the surgery. Patients and stone characteristics, mean operative time (p=0.830), complications (p=0.859) and stone-free rates (93.0%) were similar between the groups. There was a trend toward higher complication rates in Group 1, but the difference was not statistically significant. Only 21 (29.0%) of preoperatively placed PCNs were used during PCNL for establishing a tract. The reasons for not using PCN tract were: pelvic or infundibular insertion (30.0%) and suboptimal anatomic location (70.0%).

Conclusions

Preoperative emergency inserted PCNs by IR usage rates were low during PCNL. Its placement neither affects the incidence of complications nor affects the operation time and outcomes. As such, when emergency renal drainage is indicated, the need for a future definitive PCNL should not influence the decision about the modality of renal drainage.

Comorbidity and socio-demographic factors associated with renal lithiasis in persons aged 40 to 65: A cross-sectional study

BACKGROUND AND OBJECTIVE

Renal lithiasis is one of the most important urological diseases. It seems to be related to different socio-demographic and climatic factors, lifestyle and pre-existing comorbidity. The aim of this study was to examine the relationship between socio-demographic variables, certain risk factors and chronic diseases and the renal lithiasis.

PATIENTS AND METHOD

A cross-sectional population-based study was carried out, selecting the Spanish population aged from 40 to 65 years, combining 2 random samples (PreLiRenA and PreLiRenE studies). Data were collected by personal telephone surveys, gathering information on socio-demographic variables and perceived morbidity. Data on annual average temperatures in each Spanish region were also collected. A bivariate and multivariate analysis was performed.

RESULTS

A total of 4,894 subjects were surveyed; 51.3% were women; 25% were aged 40-45 years, 36% had primary school education and 31.4% were of low social class. The overall prevalence of renal lithiasis was 15.0% (95% confidence interval [95% CI] 14.5-15.5). By means of multivariate analysis, the variables that showed a strong statistical relationship with the presence of renal lithiasis were: older age (61-65 years; OR=1.39; 95% CI 1.06-1.80), high social class (OR=1.98; 95% CI 1.29-2.62), family history of renal lithiasis (OR=2.22; 95% CI 1.88-2.65), high blood pressure (OR=1.68; 95% CI 1.39-2.02) and overweight/obesity (OR=1.31; 95% CI 1.12-1.54). A correlation was observed between renal lithiasis and average annual temperatures in the Spanish regions (r=0.59; P=.013).

CONCLUSIONS

A relationship was observed between renal lithiasis and older age, belonging to higher social classes, the existence of a family history of urolithiasis, and hypertension and overweight or obesity. The prevalence of renal lithiasis is greater in warmer climate zones.

Retrograde intrarenal surgery and micro-percutaneous nephrolithotomy for renal lithiasis smaller than 2 CM

INTRODUCTION

Microperc is the upgraded form of percutaneous nephrolithotomy miniaturization. The aim of this study is to compare prospectively microperc and retrograde intrarenal surgery for the treatment of renal stones smaller than 2 cm.

MATERIAL AND METHODS

A comparative prospective study of both techniques was carried out between January 2014 and June 2015. Thirty-five patients were divided in two groups: Group A, 17 patients treated by retrograde intrarenal surgery and Group B, 18 patients treated by microperc. Stone clearance was assessed using CT scan 3 months after surgery.

RESULTS

Both groups were statistically comparable as demographic variables and stone size was similar (16.76 mm Group A vs 15.72 mm Group B). Success rate, hospital stay and JJ stenting were similar for both groups. There was no statistically significant difference regarding post-operatory complications: 17.64% Group A vs 5.56% Group B (p=0,062), all of them Clavien I and II. Surgical time was statistically different (63.82 min Group A vs 103.24 min Group B) as well as hemoglobin drop (0.62 g/dl Group A and 1.89 g/dl Group B).

CONCLUSION

Microperc is an effective and safe procedure for the treatment of renal lithiasis smaller than 2 cm, which makes it a good alternative to retrograde intrarenal surgery for this stone size. However, more prospective studies that include a larger cohort are necessary to confirm our results.

The Effect of Comprehensive Care on the Patients Received Minimally Invasive Percutaneous Nephrolithotomy

BACKGROUND

We analyzed the effect of comprehensive care on the patients who received minimally invasive percutaneous nephrolithotomy (MPCNL).

METHODS

Patients hospitalized from 2013-2014 in Zhumadian Central Hospital (n=124) were enrolled and divided into two groups on random basis. The control group was treated with routine nursing model while the observation group was given comprehensive care additionally. The surgery time, degree of comfort, complications and successful cases, hospitalization time, sleep quality, nursing satisfaction and changes of systolic pressure, pulse and respiratory at different time were observed and analyzed.

RESULTS

The surgery time of the control group was significantly longer than that of observation group (P<0.05). The observation group felt more comfortable and showed more significant successful cases than the control group. Moreover, the hospitalization time were significantly reduced in observation group when compared with control group (P<0.05). The sleep quality of the observation group was significantly better than that of the control group (P<0.05). Before anesthesia, diastolic blood pressure, systolic blood pressure, pulse and respiration were not significantly different between the two groups. The diastolic blood pressure, systolic blood pressure, pulse and respiration after anesthesia, intraoperative 30 min, postoperative 30 min and other moments were significantly different. The incidence of complications in the control group was significantly higher than that in the observation group. The nursing satisfaction of the observation group was significantly higher than that of the control group.

CONCLUSION

The comprehensive care on the patients undergoing MPCNL was effective, and it can dramatically shorten surgery time, improve the success rate, improve the sleep quality of patients, keep life sign stable and minimize the complications.

Retrograde intrarenal surgery with holmium-YAG laser lithotripsy in the primary treatment of renal lithiasis

INTRODUCTION

retrograde intrarenal surgery (RIRS) appears as a safe and effective technique as well as a good therapeutic alternative to extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL).

MATERIAL AND METHODS

descriptive study in 50 patients surgically treated between November 2012 and April 2013. Demographic, operative and postoperative data as well as early and late complications data were collected. The minimum follow-up of patients was one year. Surgery was performed under general anesthesia. Flexible ureteroscopy with ureteral access sheath and laser fragmentation were employed. Surgery success was defined as stone free rate in postoperative control test and at three months after surgery (simple radiography, abdominal ultrasound or CT without contrast).

RESULTS

mean age was 51.1±15.5 years old. The highest-frequency location was the lower calyceal group (26%), single stones were described in 58% of patients whilst multiple lithiasis were found in the 42%. Regarding the stone burden in 44% of the patients was low (<2 cm), and high (>3 cm) in 22% of the patients. The stone clearance rate was 89.7±17.5. Average surgery time was 96.6±35.2min. Complications were reported in 4 patients (8%), all of them early ones and minor in nature.

CONCLUSIONS

RIRS is an effective and safe option whose results are comparable to ESWL and PCNL. RIRS can be considered as first-line treatment. These results are corroborated by numerous studies. To strengthen these findings, prospective studies focusing on quality of life, length of stay, complications and cost-effectiveness of different treatments are needed.

[Single procedure treatment of complex nephrolithiasis: about a modern series of anatrophic nephrolithotomy]

PURPOSE

Advances in endourology have significantly reduced indications of open surgery in the treatment of staghorn calculi. However, in our experience, open surgery is still the treatment of choice in some cases. This study presents the results of a series of selected patients and discusses the results in terms of efficacy and morbidity.

MATERIALS

A cohort of 26 patients underwent anatrophic nephrolithotomy by lombotomy to treat a complex staghorn calculus.

RESULTS

The mean stone size was 68,5mm, 70% were complete staghorn calculi. The operative time was 100minutes. Blood loss was 225mL, with a postoperative transfusion rate of 15.4%. The hospital stay was 8.4 days. The stone free rate following the procedure was 92%. The creatinine clearance (MDRD) at 3 months was improved from 5.9mL/min/m(2) on average over the entire series.

CONCLUSION

There are clearly still indications for open surgery in staghorn stones management, with good results in this contemporary series on both stone removal and nephronic preservation. Yet, it appears that this technique is no longer taught.

LEVEL OF EVIDENCE

5.

Flexible ureteroscopy for renal stones

OBJECTIVES

The objectives of this prospective study are to present our experience with retrograde intrarenal surgery (RIRS), and to analyze its results and complications.

MATERIAL AND METHODS

150 patients with renal stones were treated with RIRS. 111 cases showed single stones whilst multiple stones were observed in 39 cases. The mean size was 19.12mm (r: 5-74). Success rate was defined as the absence of residual stones or the presence of fragments ≤2mm.

RESULTS

in 21 (14%) patients RIRS could not be performed on first attempt because it was impossible to place the ureteral access sheath. The immediate success rate was 85.7%, and 91.6% at three months later. The average operating time was 85min (r: 25-220). Postoperative complications were observed in 22 cases (14.6%), although most of them were classified as Clavien 1 and 2 (19 cases), and only 2% (3 cases) showed Clavien 4 complications (sepsis requiring admission in the intensive care unit). 10 patients underwent a second procedure in order to complete the treatment. Thus, the number of procedures per patient was 1.06. There were no late complications.

CONCLUSIONS

the treatment of renal stones with flexible ureteroscopy using the ureteral access sheath shows a high successful rate with a low complication rate. In order to define its indication more precisely, randomized studies comparing RIRS with minimally invasive percutaneous nephrolithotomy procedures (miniperc and microperc) would be necessary.

A new device for simple and accurate urinary pH testing by the Stone-former patient

Purpose

Urinary pH is an important factor linked to renal stone disease and a useful marker in the treatment of urolithiasis. Although the gold standard for measuring urinary pH utilizes a glass electrode and a pH meter, at present dipstick testing is largely used to estimate urinary pH. However, the accuracy and precision of this method may be insufficient for making clinical decisions in patients with lithiasis. The aim of this study is to describe a new device for urinary pH testing.

Methods

The device includes a pH sensor based on differential measurement of an ISFET-REFET pair. The drawbacks associated with this type of configuration, namely short lifetime and manual fabrication, have been overcome in the prototype. An automatic one point calibration is performed when turning on the system. Two buffer solutions were utilized to determine the intra- and inter-day precision of the device. The pH of 30 fresh human urine samples was measured using a pH-meter, a dipstick and the new electronic device.

Results

In some cases, dipstick measurements differed from those of the pH meter by more than 0.40 units, a clinically relevant discrepancy, whereas none of the measurements made with the new electronic device differed from the results of the pH-meter by more than 0.1 pH units.

Conclusions

This new electronic device has the possibility to be used by stone-formers to control their urinary pH at home, increasing the tools available for stone prevention and prophylaxis.

A comparative study of percutaneous nephrolithotomy in supine position and endoscopic combined intrarenal surgery with flexible instrument

OBJECTIVE

To compare the results obtained in percutaneous nephrolithotomy after introduction of flexible ureteroscopy/nephroscopy (endoscopic combined intrarenal surgery - ECIRS) with nephrolitomies with only rigid nephroscopy (standard percutaneous nephrolithotomy; sPCNL).

MATERIAL AND METHOD

A retrospective study of 171 sPCNL in Galdakao position performed between January 2005 and December 2011 was conducted. We compared the results obtained in those procedures in which endoscopic combined intrarenal surgery (ECIRS) was performed with those in which only the rigid nephroscopy (sPCNL) was used. Specific and global success, percentage of lithiasic load eliminated, days of hospital stay and complications derived were calculated. We defined success by complete absence of lithiasis or residual presence of<5mm. We differentiated specific success, that only achieved with percutaneous surgery, from global success, or that achieved after a second line of treatment.

RESULTS

In 73 procedures (42.4%) ECIRS was performed with flexible endoscopy while in 98 (57.6%) it was done with sPCNL. Both groups were comparable in regards to demographic parameters and characteristics of the lithiasis. The success rates in the first procedure and global success were superior for the ECIRS group (75.3% vs 40.8% and 93.1% vs 74.5%), the differences being statistically significant (P<.05). No statistically significant differences were found in regards to the complications (28.8% vs 28.3% P=.86) or days of hospital stay (4.5 vs 5.0 P=.18).

CONCLUSIONS

Use of the flexible ureteroscopy/nephroscopy in sPCNL (ECIRS) improves the success rates and elimination of lithiasic load, making it possible to perform the surgery with a single access in most of the cases.