Prediction of residual total renal function before nephron-sparing surgery using99mTc-DMSA renal scintigraphy

Background Although radical nephrectomy is the standard treatment for renal cell carcinoma, nephron-sparing surgery is the preferred treatment in patients with a single functioning kidney. It is important before surgery to evaluate the level of residual renal function likely after the operation. In this study, we investigated the prediction of residual renal function, using technetium Tc 99m dimercaptosuccinic acid (^99mTc-DMSA) renal scintigraphy, before nephron-sparing surgery for renal tumors. Methods Preoperative and postoperative evaluation of renal function was done in 11 patients with renal cell carcinoma or renal angiomyolipoma, using^99mTc-DMSA scintigraphy. Nine patients had renal cell carcinoma and 2 had renal angiomyolipoma. Partial nephrectomy was performed in 4 patients and surgical enucleation in 7 patients. Both the predicted total DMSA renal uptake rate prior to surgery and the actual postoperative total^99mTc-DMSA renal uptake rate were obtained. Endogenous creatinine clearance and serum creatinine levels were also obtained. Results There was a good relationship between the predicted and postoperative total^99mTc-DMSA renal uptake rates. The ratio of the postoperative total DMSA renal uptake rate to the predicted total^99mTc-DMSA renal uptake rate was 85% after partial nephrectomy, and 101% after surgical enucleation. There was also a significant correlation between the postoperative total^99mTc-DMSA renal uptake rate and creatinine clearance, and postoperative total^99mTc-DMSA renal uptake rate levels above 11.4% coincided with serum creatinine levels below 2.0 mg/dL. Conclusion Preoperative assessment with^99mTc-DMSA renal scintigraphy is clinically useful for predicting residual renal function after nephron-sparing surgery.     

Protective effects of thymol against nephrotoxicity induced by cisplatin with using 99mTc-DMSA in mice

Abstract

Background: In this study, we investigated the protective effect of thymol as a natural compound against cisplatin-induced nephrotoxicity by quantitative renal ^99mTc-DMSA uptake and compared its effect with histopathology in mice. Materials and methods: Mice were divided into six groups as control, cisplatin (7.5?mg/kg, intraperitoneally), thymol?+?cisplatin (thymol; 50 and 150?mg/kg?+?cisplatin; 7.5?mg/kg) and thymol (50 and 150?mg/kg). Thymol was orally administrated for two days before cisplatin injection and continued for 4 days. ^99mTc-DMSA was injected through the tail of mice after the drug administration. The percentage of the injected dose per gram of kidney tissue (%ID/g) was calculated. In other experiment, kidneys of treated mice were assessed for histopathology. Results: ^99mTc-DMSA uptake per gram tissue of the kidneys as %ID/g was 85.27?±?21.81, 45.55?±?5.50, 65.02?±?32.21 and 88.46?±?20.46 in the control, cisplatin, thymol (50?mg/kg)?+?cisplatin and thymol (150?mg/kg)?+?cisplatin. Thymol administration with cisplatin resulted in a significant increase in the level of %ID/g. Histopathological examinations showed a protective effect of thymol against cisplatin nephrotoxicity in mice. Conclusion: The results showed that thymol significantly attenuates the cisplatin-induced nephrotoxicity in mice, and ^99mTc-DMSA uptake in kidney is a suitable method for assessment of nephrotoxicity in mice.     

Laparoscopic pyelolithotomy versus percutaneous nephrolithotomy for treatment of large renal pelvic calculi (diameter >2 cm): a meta-analysis

Objective: To systematically assess the efficacy and safety of laparoscopic pyelolithotomy (LP) versus percutaneous nephrolithotomy (PCNL) for the treatment of renal pelvic calculi >2?cm.

Methods: We searched PubMed, Embase, Cochrane Library, and Google Scholar about LP and PCNL for the treatment of renal stones. The retrieval time ended in September 2015. Two reviewers independently assessed the quality of all included studies. The available data in the studies were analyzed using the RevMan 5.2 software.

Results: Four randomized controlled trials (RCTs) and nine Non-Randomized Concurrent Controlled Trials (NRCCTs) were included, involving a total of 766 patients. This meta-analysis showed that LP has a statistically higher stone-free rate than PCNL [I^2?=?0, OR?=?0.26 (95% CI 0.10–0.64), p?=?0.003], lower drop in hemoglobin level [I^2?=^?0, difference in mean drop?=??0.83 (95% CI ?1.05 to ?0.61), p?I^2?=^?0, OR?=?0.36 (95% CI 0.14–0.89), p?=?0.03], and PCNL is associated with a lower length of hospital stay [I^2?=^?74%, difference in mean of hospital stay?=?0.72 (95% CI 0.04–1.40), p?=?0.04].

Conclusion: LP is an alternative for the treatment of large solitary renal stone. LP may have a higher stone-free rate, lesser blood loss, lower postoperation fever rate, while PCNL may have a lower length of hospital stay. However, further well designed and large volume randomized controlled trials are needed to confirm these findings.     

Vesico-ureteric reflux in the damaged non-scarred kidney

Renal damage without scarring is a rare manifestation of reflux nephropathy, and is infrequently reported in the literature. A retrospective review of a large series of patients with urinary tract disorders at the hospital for Sick Children, Great Ormond Street, identified 12 patients with vesico-ureteric reflux (VUR) with no evidence of scarring but with renal damage as assessed using technetium 99m dimercaptosuccinic acid (^99mTc-DMSA) scan. There were 9 simplex kidneys, the differential function was between 33% and 43% (mean 38%). On follow-up to date (mean 6.7 years) all kidneys show stable differential function with neither improvement nor deterioration. Only 8 children had a urinary tract infection. Renal damage without evidence of a focal scar associated with VUR may be a manifestation of growth arrest possible due to glomerular damage. The sensitivity of^99mTc-DMSA may reveal the permanent nature of the renal damage.     

The Role of Percutaneous Nephrolithotomy in the Management of Medium-Sized (1–2 cm) Lower-Pole Renal Calculi

Objectives : The objective of this study was to determine the efficacy (defined by stone-free rates) and safety of percutaneous nephrolithotomy (PNL) in the treatment of medium sized (1–2 cm) symptomatic lower pole renal calculi, and establishment of the short-term morbidity.

Methods : We performed a retrospective analysis of 60 evaluable patients who had undergone PNL for 1 to 2 cm diameter lower-pole (LP) stones between November 2006 to March 2009 and compared these results with other treatment modalities in published literature.

Results : In all cases, stones were located in the lower calix. Thirty-six procedures were performed on the left side, and 24 were performed on the right side. The mean time to access the collecting system was 20.4 minutes (range 8–70 min) and mean operative time was 62.2 minutes (range 13–155 min). Abdominal radiography performed on postoperative day 1 demonstrated a stone free status in 56 (93.3%) patients. However, 4 patients (6.7%) required ancillary procedures (secondary PNL in 1, retrograde intrarenal surgery in 1, and SWL in 2). After this secondary procedures a complete stone-free status was achieved in 98.3% of patients. The morbidity of patients undergoing PNL at our hospital was minimal, with a mean hospital stay of 3.7 days.

Conclusions : We demonstrated that, PNL is a safe and effective method for medium sized (1 to 2 cm) lower pole renal calculi and percutaneous removal should be considered the primary approach for lower pole stones greater than 10 mm.     

Efficacy of magnetic resonance urography in detecting renal scars in children with vesicoureteral reflux

Background

The detection of renal scars is of paramount importance for optimal clinical management of patients with urinary tract infection (UTI) and vesicoureteral reflux (VUR). The aim of our study was to compare the efficacy of unenhanced magnetic resonance urography (MRU) and Tc-99^m dimercaptosuccinic acid (Tc-DMSA) scintigraphy to dectect renal scars.

Methods

Unenhanced MRU and Tc-DMSA scintigraphy were performed in 49 children (10 boys, 39 girls; mean age 7.4?±?4.2 years, range 1–15 years) with documented VUR. MR imaging scans were obtained within 7 days after voiding cystourethrogram (VCUG) and Tc-DMSA scintigraphy. The diagnostic performance of MRU in renal scar detection was calculated relative to that of the Tc-DMSA scan.

Results

The renal scar detection rate of Tc-DMSA scintigraphy and unenhanced MRU in kidneys with VUR was 32.4 and 25.9 %, respectively. The sensitivity and specificity of MRU in the detection of renal scars was 80 and 82.6 % in kidneys with VUR, respectively. There was no statistically significant difference in lesion detection between MRU and Tc-DMSA scintigraphy (P?>?0.05). MRU and Tc-DMSA scintigraphy showed good agreement (κ?=?0.60).

Conclusions

Unenhanced MRU is a robust technique for the morphologic assessment of the urinary system and detection of renal scars. The lack of radiation and contrast material makes this technique a much safer alternative to scintigraphy in children with VUR, particularly in those who require follow-up scanning and, consequently, considerable radiation exposure.     

Tc-DMSA scanning to diagnose pyelonephritic scarring in children

^99mTechnetium-labeled dimercaptosuccinic acid (^99mTc-DMSA) scanning provides superior quality images of renal parenchymal detail, which makes it highly sensitive for the diagnosis of pyelonephritic scarring. Unlike most other imaging techniques, radionuclide scanning is not affected by bowel gas or bony structures overlying the kidneys. This makes it particularly useful in children. Furthermore, renal scarring can be demonstrated by ^99mTc-DMSA even before the classic gross anatomic and radiologic changes are present. The use of ^99mTc-DMSA scanning in over 300 children has demonstrated its benefits and advantages over standard radiographic techniques.     

Safety and efficacy of retrograde intrarenal surgery for the treatment of renal stone in solitary kidney patients

Purpose: We present our experience of retrograde intrarenal surgery (RIRS) for the treatment of renal stones in patients with solitary kidneys and evaluate the safety and efficacy of this treatment modality.

Materials and methods: Between March 2011 and July 2015, the clinical records of 60 patients with renal stones in solitary kidneys who underwent RIRS were retrospectively reviewed. Demographic characteristics, preoperative urinary culture, blood biochemistry, stone location, and surface area were documented. The final stone-free rates (SFRs) were assessed one month after the last treatment session by computed tomography (CT). Preoperative, operative, and postoperative parameters were analyzed. Serum creatinine (Scr) and glomerular filtration rate (GFR) were measured preoperatively, one month postoperatively, and at each follow-up visit.

Results: The mean stone burden was 628?±?27.2?mm² (range 301–1199). The mean operative time was 84.4?±?21.3?min (range 40–115). The mean drop in postoperative hemoglobin was 0.6?±?0.21?g/dL (range 0.1–0.7). Twelve patients (20%) required second-stage RIRS for residual stones. The SFRs after the single and second procedures were 80% and 95%, respectively. The mean preoperative Scr level was 111.6?±?45.59?μmol/L, and the mean postoperative Scr level was 96.7?±?34.12?μmol/L. The change was statistically significant (p?=?.008). The same findings were observed for GFR. The mean preoperative GFR was 65.04?±?25.37?ml/min, and the mean postoperative GFR was 76.89?±?27.2?ml/min (p?=?.023). Minor complications occurred in nine patients (15%). One patient experienced septic shock and acute renal failure due to steinstrasse. This patient required hemodialysis and percutaneous nephrostomy drainage. One patient developed perirenal abscess and was treated with percutaneous drainage.

Conclusion: RIRS is a safe and effective procedure for the treatment of renal stones in patients with solitary kidneys. RIRS did not adversely affect renal function at either the short-term or the long-term follow-up.     

Febuxostat for treating allopurinol-resistant hyperuricemia in patients with chronic kidney disease

Background: Availability of the novel xanthine oxidase inhibitor febuxostat, which has multiple excretion pathways, enables investigation of the significance of serum uric acid control on renal function in patients with chronic kidney disease (CKD). Methods: This was an exploratory, retrospective, observational study conducted at a single Japanese center. Serum uric acid concentrations and serum creatinine levels in the 6 months before and after the start of febuxostat treatment were collected for CKD patients switched from allopurinol after failing to achieve serum uric acid concentrations ≤6.0?mg/dL. Results: Evaluable data were available for 60 patients, 67% of whom had advanced CKD (eGFR <30?mL/min/1.73?m²). Mean dose of febuxostat was 15.9 (±?8)?mg/day. Mean serum uric acid concentration decreased from 8.4 (±1.4) mg/dL at baseline to 6.2 (±1.2)?mg/dL at 6 months; 47.5% of patients achieved a level ≤6.0?mg/dL. The change from baseline in eGFR was positive at all time points during febuxostat treatment and the increase of 2.3 (±5.6)?mL/min/1.73?m² at 6 months was significant (p?=?0.0027). Whereas the eGFR slope was negative during allopurinol treatment, it became positive after the switch to febuxostat. The change in eGFR slope before and after febuxostat treatment was significant for all patients (p?p?2 (p?Conclusions: In patients with CKD, febuxostat reduces serum uric acid concentrations effectively and may suppress the progressive decline in renal function.     

Radionuclide Staging of Renal Function in Type 1 Diabetes Mellitus

Aim. The aim of this study was to assess renal function in different stages of type 1 diabetes mellitus by radionuclide methods. Additionally, glomerular and tubular functions were correlated with urinary albumin (UAER) and N-acetyl-β-D-glucosaminidase (NAGA) excretion rates. Patients and methods. Fifty-three patients with diabetes mellitus were classified into four groups: normoalbuminuric (NA, 18 patients), microalbuminuric (MiA, 12 patients), macroalbuminuric (MaA, 13 patients), and chronic renal failure group (CRF, 10 patients). Glomerular filtration rate (GFR) was estimated by diethylenetriamine pentaacetic acid-technetium 99m (^99mTc-DTPA) clearance rate while tubular function was calculated as a percentage of net injected activity fixed in both kidneys, 4 h after intravenous injection of dimercaptosuccinate acid-technetium 99m (^99mTc-DMSA). Additionally, ^99mTc-DTPA clearance was correlated with estimated GFR (eGFR) by using modified Modification of Diet in Renal Disease (MDRD) Study Group formula. Results. ^99mTc-DTPA clearance and ^99mTc-DMSA fixation were found significantly higher in normoalbuminuric group (p < 0.05 and p < 0.02, respectively), unchanged in microalbuminuric group (p > 0.05, p > 0.05), and decreased in both macroalbuminuric (p < 0.0001, p < 0.00001) and chronic renal failure group (p < 0.0001, p < 0.00001). Renal function was denoted as normal, increased (hyperfunction), or decreased (hypofunction). It was found normal in a high percentage of patients with normalbuminuria (filtration 44.4%, fixation 72.2% pts) and microalbuminuria (66.7% and 66.7%). Renal hyperfunction was not only found frequent in normalbuminuric group (55.6% and 27.8%), but was also recorded in microalbuminuric group (8.3% and 8.3%). Renal hypofunction was present in all macroalbuminuric patients and in one-quarter of those with microalbuminuria as well. Such distribution of renal function conditions indicated normalbuminuric and microalbuminiric groups functionally heterogeneous. Regression analysis showed a significant correlation between ^99mTc-DTPA clearance and eGFR in MaA and CRF groups only. Although urinary NAGA excretion rate was shown as a less sensitive staging parameter, being significantly increased when compared to control group only in MaA and CRF groups (p < 0.05), it significantly correlated with ^99mTc-DTPA clearance rate (r = ?0.485, p = 0.0004) and ^99mTc-DMSA tubular fixation (r = ?0.526, p = 0.0002). Conclusions. The results of this study favor the performance of radionuclide studies together with the determination of urinary albumin excretion rate in patients with type 1 diabetes mellitus in order to achieve more reliable staging of diabetic kidney disease. The demonstration of glomerular hyperfiltration and tubular hyperfunction by radiopharmaceuticals contributes to the early detection of diabetic kidney disease, while the quantification of renal function enables the follow-up of the progressive function loss in the later course of the disease.     

Long-term results of percutaneous nephrolithotomy for treatment of staghorn stones

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Short‐term results; as stone‐free and complication rates; of percutaneous nephrolithotomy for treatment of staghorn stones. Long‐term results of PNL; as recurrence rate and differential renal functional changes for treatment of staghorn stones with focus.

OBJECTIVE

? To study long‐term results of percutaneous nephrolithotomy (PNL) for treatment of staghorn stones.

PATIENTS AND METHODS

? The records of patients who underwent PNL for staghorn stones between January 1998 and January 2008 were retrospectively reviewed. ? Patients who completed follow‐up for one year or more were included. Follow‐up with KUB and renal ultrasonography were performed every 3–6 months. ? Renal radioisotopic scan was performed for patients who had already undergone this study before doing PNL.

RESULTS

? The study included 122 patients (69 male and 53 female) with mean age 47.6 ± 14.5 years (5–74). They underwent 126 PNL. ? Perioperative complications were encountered in 28 procedures (22%). The mean period of follow‐up was 3.5 ± 2.3 years (1–11.3). Among 71 stone‐free kidneys, 18 (25%) developed stone recurrence. Of 55 kidneys with residuals at the start of follow‐up, 36 (65%) showed growth of these residuals. ? Preoperative and postoperative renograms were performed for 71 patients. ? At the last follow‐up, differential GFR was stable in 53 (74.5%), improved in 12 (17%) and deteriorated in 6 (8.5%). Among patients with deteriorated renal function, 3 had undergone embolization to control severe bleeding, one developed secondary UPJO, and one had recurrent stone obstructing the kidney.

CONCLUSION

? Long‐term functional results of PNL for staghorn stones are satisfactory as 91.5% of kidneys showed stable or improved GFR. Long‐term follow‐up is mandatory especially for patients with residual stones.     

Estimation of Differential Renal Function in Children With a Prenatal Diagnosis of Unilateral Pelvic Dilatation

Purpose

We compared the estimation of differential renal function by sup 99m technetium (Tc)-dimercapto-succinic acid (DMSA) and ^99mTc-pentetic acid scintigraphic methods for followup of prenatally diagnosed unilateral renal pelvic dilatation.

Materials and Methods

We retrospectively analyzed differential renal function estimations calculated by static and dynamic methods in time matched test pairs that were included in the charts of 51 children monitored for prenatally diagnosed unilateral renal pelvic dilatation at our institution in a 5-year period.

Results

There were 96 test pairs with available archived raw data. Using the analytic method of assessment of agreement between the 2 tests, a 95% limit of agreement of +/−9% was calculated. Of the 96 pairs of tests the results of 94 revealed no significant difference. Subgroup analysis by patient age and operative intervention (13 postoperative pairs) also showed no difference in the results of the 2 tests.

Conclusions

We established the 95% limits of agreement between ^99mTc-DMSA and ^99mTc-pentetic acid tests of differential renal function to be +/−9% discrepancy in 96 test pairs. During followup of prenatally diagnosed unilateral renal pelvic dilatation the assessment of differential renal function can be made by ^99mTc-DMSA static or dynamic diuretic renography techniques. This interchangeability is consistent at all patient ages regardless of operative intervention. Since dynamic diuretic renography provides differential function and drainage data, using ^99mTc-DMSA in this context is unnecessary and subjects patients to an unnecessary radiation burden.     

Significance of mast cell renal infiltration in patients with anti-GBM nephritis

To investigate the role of mast cells (MCs) renal infiltration in the progression of human anti-GBM nephritis, 38 patients diagnosed with anti-GBM nephritis were enrolled. Renal biopsies were performed. Immunohistochemistry was conducted to detect MCs in renal tissues. Patients were divided into group 1 (MCs?<50?mm^?2, n?=?18) and group 2 (MCs?≥50?mm^?2, n?=?20) according to the infiltrating renal MC count. The clinical–pathological indices were compared. And, correlation between MCs and the clinical–pathological indices was analyzed. Patients of group 2 had more severe renal dysfunctions, expressed as higher levels of serum creatinine (SCr 8.95?±?3.66 vs. 4.75?±?2.73?mg/dL, p?<?0.001), urine retinol-binding protein (RBP 29.8?±?13.9 vs. 15.7?±?11.5?mg/dL, p?=?0.005), and lower urinary osmotic pressure. Pathologically, patients of group 2 had a higher percentage of fibrous/fibrocellular crescents (66.7?±?21.9 vs. 47.0?±?33.6%, p?=?0.037) but a lower percentage of cellular crescents. More CD8 (268?mm^?2 vs. 180?mm^?2, p?=?0.045) and CD68 (268?mm^?2 vs. 180?mm^?2, p?=?0.045) positive cells infiltrating the interstitium were observed in group 2. Furthermore, renal MCs correlated significantly with the total number of crescents and the tubular interstitial CD8 and CD68 positive cells. And, the number of MCs was associated with the histological types. The renal function was significantly different between the two groups at presentation. However, at 3 and 6 month follow-up, the patient outcome was associated with the histological types. Our study showed that MC infiltrations were associated with chronic lesions in anti-GBM nephritis and may be involved in the loss of renal function with pathological changes.     

The comparison of laparoscopic pyelolithotomy and percutaneous nephrolithotomy in the treatment of solitary large renal pelvic stones

The aim of the study is to investigate whether laparoscopic pyelolithotomy (LPL) could find a place in the management of large renal pelvic stones which are generally considered as excellent indications for percutaneous nephrolithotomy (PNL). Between 2006 and 2009, 26 consecutive patients with large (>4?cm(2)) renal pelvic stones were treated by LPL and their charts were compared to 26 match-paired patients treated with PNL during the same period. The patients were matched for age, BMI, stone size and location as well as presence of congenital anomalies. Perioperative and postoperative findings were compared. The mean age, mean stone size, rate of congenital anomalies, history open renal surgery and shock wave lithotripsy were similar in both groups (p?>?0.05). The mean operation time was 138.40?±?51.19 (range 70-240)?min in LPL group as compared to 57.92?±?21.12 (range 40-110)?min in PNL group (p?相似文献   

Prospective comparative study of miniperc and standard PNL for treatment of 1 to 2 cm size renal stone

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Standard PNL is known to have higher clearance rates for stones 1–2 cm. However, it is not promoted because of its associated morbidity, especially bleeding. Minitiarization of the PNL has spawned a new interest in this modality for treating small bulk urolithiasis. The study adds to a growing body of evidence in a prospective manner that smaller tract PNL “miniperc” is associated with a similiar efficacy of achieving stone‐clearance rates while decreasing the invasiveness of the procedure and associated morbidity.

OBJECTIVE

? To evaluate the results of miniperc vis‐à‐vis standard PNL in the treatment of stones of 1–2 cm in size. Miniperc may represent a reasonable procedure in patients with nonbulky urolithiasis offering a similar outcome as standard percutaneous nephrolithotomy (PNL) with advantage of reduced morbidity.

PATIENTS AND METHODS

? 55 procedures including 27 miniperc and 28 standard PNL were performed for renal stones 1–2 cm in size. Pediatric patient, active urinary tract infection, renal malformation, uncorrected coagulopathy and morbid obesity patients were excluded from the study. ? The parameters studied were demography, operative time, postoperative analgesic requirement, hemoglobin drop, complications and stone clearance.

RESULTS

? Mean tract size was 18.2 ± 2 F (15–20) and 26.8 ± 2 F (24–30), P value <0.0001 in the miniperc and standard PNL, respectively. Holmium LASER and pneumatic lithotripter were the main energy sources used in miniperc and standard PNL, respectively. ? Miniperc operative time was longer than that of standard PNL (45.2 ± 12.6 vs 31 ± 16.6 min, P= 0.0008 respectively). ? Conversely, there was an advantage of miniperc over standard PNL in terms of a significantly reduced hemoglobin drop (0.8 ± 0.9 vs 1.3 ± 0.4 gram%, P= 0.01), analgesic requirement (55.4 ± 50 vs 70.2 ± 52 mg tramadol, P= 0.29) and hospital stay (3.2 ± 0.8 vs 4.8 ± 0.6 days, P≤ 0.001), respectively. ? Intra‐ operative conversion of the procedure into a tubeless PNL was significantly more in the miniperc group (P≤ 0.001). The miniperc and standard PNL group had clearance rates of 96% and 100%, respectively at 1 month follow up.

CONCLUSIONS

? This study demonstrated significant advantages of the miniperc procedure in terms of reduced bleeding leading to a tubeless procedure and reduced hospital stay. ? The stone free rates and the complications were similar in either group.     

Poor renal uptake of99mtechnetium-dimercaptosuccinic acid and near-normal99mtechnetium-mercaptoacetyltriglycine renogram in nephronophthisis

Four patients with the clinical diagnosis of nephronophthisis are presented, all having a very poor renal uptake of^99mtechnetium-dimercaptosuccinic acid (^99mTc-DMSA) but clearly visualized kidneys on early images with^99mtechnetium-mercaptoacetyltriglycine and a normal or almost normal renogram. There was no difference between a young patient in an early stage of the disease and the other three patients with more advanced renal disease. In contrast, a patient with tubulointerstitial nephritis with uveitis had considerably better renal uptake of^99mTc-DMSA despite impaired renal function. We suggest that the specific tubular function defect in nephronophthisis might be the cause of the poor uptake of^99mTc-DMSA. We also recommend the method to support the clinical suspicion of nephronophthisis, even in the early stages of the disease.     

Decreased renal uptake of <Superscript>99m</Superscript>Tc-DMSA in patients with tubular proteinuria

Although technetium-99m-dimercaptosuccinic acid (^99mTc-DMSA) renal scans are widely used to evaluate renal tubular mass function, the mechanism by which renal uptake of DMSA occurs is still the subject of debate. Patients with various proximal tubular disorders show markedly decreased renal DMSA uptake, even when there is normal creatinine clearance. We measured the renal uptake of ^99mTc-DMSA 3 h after its injection in 13 patients with Dent disease or Lowe syndrome, both of which are typical proximal tubular disorders with defective megalin and cubilin-mediated endocytosis. Serial images of three patients were also obtained at 0.5, 1, 2 and 3 h post-injection. The correlations between renal uptake of ^99mTc-DMSA and creatinine clearance and the degrees of acidemia and tubular proteinuria were then evaluated. The renal uptake of ^99mTc-DMSA was markedly decreased in all patients, and the decreased uptake was detected in all serial images. In contrast, bladder radioactivity was higher than normal in all of the serial images when compared to renal radioactivity. Additionally, the uptake of ^99mTc-DMSA was inversely proportional to the amount of urine β₂-microglobulin. These results strongly suggest that DMSA is filtered in the glomeruli and subsequently undergoes megalin- and cubilin-mediated endocytosis in the proximal tubules.     

99mTc-dimercaptosuccinic Acid Tubular Fixation in Diabetic Nephropathy Patients

Dimercaptosuccinic acid labeled with technetium-99m (^99mTc-DMSA) has been reported to be a good agent for quantitative estimation of renal function. Its biodistribution is found to be altered in tubular disorders. The aim of the present study was to assess tubular function in diabetic nephropathy patients by studying ^99mTc-DMSA biodistribution and to compare the findings obtained with those of primary glomerulonephritis patients. This study included 18 insulin-dependent patients with overt diabetic nephropathy and 16 glomerulonephritis patients with normal serum creatinine levels and moderately decreased glomerular filtration rate. Renal fixation of ^99mTc-DMSA and whole blood activity 2 and 4 h following radiopharmaceutical injection, as well as 4 h cumulative urinary excretion were determined. All values were expressed as per cent of net administered activity. ^99mTc-DMSA renal accumulation was significantly decreased (p<0.001), while urinary excretion was increased (p<0.005) in both groups examined, as compared to 15 healthy persons. The reduction in ^99mTc-DMSA renal fixation was more marked in diabetic nephropathy than in glomerulonephritis (p<0.05). Whole blood activity was markedly higher in diabetic patients (p<0.05), but nonsignificantly increased in glomerulonephritis patients. Markedly decreased tubular fixation of ^99mTc-DMSA associated with high blood activity and increased urinary excretion demonstrated more pronounced tubular dysfunction in diabetic nephropathy than in primary glomerulonephritis at the same level of glomerular filtration rate.     

Avoidance of polypharmacy and excessive blood pressure control is associated with improved renal function in older patients

Abstract

Background: Elderly patients are particularly susceptible to polypharmacy. The present study evaluated the renal effects of optimizing potentially nephrotoxic medications in an older population. Methods: Retrospective study of patients’ ≥60 years treated between January of 2013 and February of 2015 in a Nephrology Clinic. The renal effect of avoiding polypharmacy was studied. Results: Sixty-one patients were studied. Median age was 81 years (range 60–94). Twenty-five patients (41%) were male. NSAIDs alone were stopped in seven patients (11.4%), a dose reduction in antihypertensives was done in 11 patients (18%), one or more antihypertensives were discontinued in 20 patients (32.7%) and discontinuation and dose reduction of multiple medications was carried out in 23 patients (37.7%). The number of antihypertensives was reduced from a median of 3 (range of 0–8) at baseline to a median of 2 (range 0–7), p?<?0.001 after intervention. After intervention, the glomerular filtration rate (GFR) improved significantly, from a baseline of 32?±?15.5?cc/min/1.73m² to 39.5?±?17?cc/min/1.73m² at t1 (p?<?0.001) and 44.5?±?18.7?cc/min/1.73m² at t2 (p?<?0.001 vs. baseline). In a multivariate model, after adjusting for ACEIs/ARBs discontinuation/dose reduction, NSAIDs use and change in DBP, an increase in SBP at time 1 remained significantly associated with increments in GFR on follow-up (estimate?=?0.20, p?=?0.01). Conclusions: Avoidance of polypharmacy was associated with an improvement in renal function.     

Percutaneous nephrolithotomy for the treatment of radiolucent renal stones in children: is it different opaque stone treatment?

We aimed to evaluate the effectiveness of percutaneous nephrolithotomy (PNL), stone-free rates, and related complications in children with radiolucent renal stones. A total of 56 patients aged <16 years from four institutions were enrolled in our study. Asymptomatic, clinically insignificant residual fragments measuring <4 mm or a complete stone-free status was accepted as the criterion for clinical success. Complications were evaluated according to the modified Clavien classification. The mean age of the patients was 7.8 ± 4.5 years. The mean stone size was calculated as 24.07 ± 10.4 mm. The median operative and fluoroscopy times were 53.2 min (15–170 min) and 172.4 s (5–520 s), respectively. The success rate after PNL monotherapy was 87.4 %; the total success rate with shock wave lithotripsy used as an auxillary treatment method was detected as 94.6 %. The total complication rate was 19.6 % (11 patients). No adjacent organ injury was observed. All of the complications that occurred were minor according to the Clavien classification (Clavien Grades I–II). PNL can be applied to radiolucent pediatric renal stones in children with similar success, and complication rates as noted for radiopaque stones.