Renal oncocytoma. A rare entity in Poland

Renal oncocytoma represents a special category of renal tumours and accounts for 3–5% of renal neoplasms. Usually they are incidental findings. Most reports have demonstrated their benign nature but a few cases of high-grade oncocytomas were reported to have metastasized. In Poland, between 1971 and 1991, 7 patients (4 women, 3 men) underwent radical nephrectomy for oncocytoma. The author describes here one case of rare oncocytoma malignum.     

Study of the microstructure of renal stones: Uric acid and calcium oxalate

This paper represents the results of experimental study on the microstructure of uric acid and calcium oxalate crystallites in renal stones. The size distribution parameters and morphological characteristics of the microcrystals forming the stone were determined using SEM and image analysing system. Information on the fabric of the renal stones examined indicates that the mean volume diameter is 15.5 m for uric acid and 32 m for calcium oxalate stones. The polydispersity index , the shape factor , and the distribution of particle shape show close similarity. Quantitative studies on stone microstructure could furnish valuable information on stone genesis.This work was supported by the Kidney Foundation and by the Medical Research Council of Canada.     

Clinically applicable upper tract urodynamics: State of art

Summary The evaluation and appropriate management of the dilated upper urinary tract represents a significant clinically relevant problem. The problem centers around defining what is obstruction. That is determining what systems have impaired urinary flow and what degree of flow impairment is required to cause renal function and anatomic changes. Diuretic renography provides a non-invasive and valuable modality for assessing the function of most wide upper urinary tracts. When equivocal results are obtained with diuretic renography, more invasive perfusion studies may be required.     

Hypokalemic rhabdomyolysis in a child with Bartter’s syndrome

Hypokalemia represents a rare cause of rhabdomyolysis. Some reports have described a few adult patients affected by Bartters syndrome and Gitelmans syndrome with rhabdomyolysis due to severe hypokalemia. We report the first pediatric patient with Bartters syndrome in whom rhabdomyolysis developed when her plasma potassium level was less than 2 mEq/l. Prompt intravenous fluid and potassium prevented tubular damage and acute renal failure. We recommend determining serum creatine phosphokinase in all patients affected by Bartters syndrome and profound hypokalemia.     

On the pathogenesis of renal tuberculosis with special reference to the role of local factors

The author considers the disturbances of urine flow from the kidney to be an important pathogenetic factor in renal tuberculosis and in nonspecific pyelonephritis. The study of more than 1200 patients with renal tuberculosis has revealed that pathologic pregnancy and childbirth, pyelonephritis of pregnancy, renal anomalies and certain other local conditions play roles in the pathogenesis of renal tuberculosis. The complications of pregnancy are the commonest unfavourable local factors which induce reactivation of dormant small tuberculous foci in the renal cortex. They cause the higher incidence of renal tuberculosis in women. Experiments involving 63 rabbits elucidated the role of urine flow obstruction in the transformation of miliary tuberculous foci in the renal cortex (subclinical changes) into destructive tuberculosis of the medulla (clinical changes). The renal tuberculosis resembling the human one including tuberculous pyelonephrosis developed only as a result of urinary obstruction. Not only patients with extrarenal tuberculosis but also ones with local pathologic urogenital changes need prophylactic investigations for early detection of renal tuberculosis.     

Postoperative Renal Function After Elective Abdominal Aortic Aneurysm Repair Requiring Suprarenal Aortic Cross-Clamping

Purpose To examine postoperative renal function after suprarenal aortic cross-clamping performed without renal hypothermia in patients undergoing elective abdominal aortic aneurysm (AAA) surgery.Methods Between 1991 and 2000, 18 patients underwent surgery for a juxtarenal AAA, which required a suprarenal aortic cross-clamp. All AAAs were repaired with a proximal anastomosis just below the renal arteries. We divided the patients into two groups according to the duration of the renal ischemia: <45min (n = 12) and 45min (n = 6). The postoperative changes in renal function were analyzed.Results There were no hospital deaths and none of the patients needed permanent hemodialysis. The postoperative peak in the serum creatinine level after suprarenal cross-clamping for 45min was significantly higher than that after cross-clamping for <45min. The percentage changes in serum creatinine and blood urea nitrogen were correlated positively with the duration of renal ischemia, and were significantly greater in the group with renal ischemia of <45min than in the group with prolonged renal ischemia (45min).Conclusions Suprarenal aortic cross-clamp without performing renal hypothermia is safe and able to be tolerated well by the patient during elective AAA surgery, although careful attention must be paid to limiting the period of renal ischemia.     

Robot-assisted renal artery aneurysm repair with a saphenous vein Y-graft interposition

Background

Renal artery aneurysms (RAA) treatment includes both surgical repair and endovascular techniques, mostly depending on the location of aneurysm [1]. For complex RAA located at renal artery bifurcation or distally, open surgical repair represents the gold standard of treatment [2]. However, the transperitoneal open access to the renal artery requires a wide laparotomy—hence the attempt to be minimally invasive with the first reports of laparoscopic approach [3, 4]. Even if it represents a possibility, laparoscopy has not yet gained widespread acceptance for the technical difficulties in performing vascular anastomosis. We herein describe the repair of a complex RAA using the Da Vinci Surgical System.

Methods

A 41-year-old woman had an accidentally discovered saccular aneurysm of the right renal artery with a maximum diameter of 20 mm, with one in and four out. A laparoscopic robot-assisted approach was planned. Intraoperatively, we confirm the strategy to group the four output branches in two different patches. Thus, a Y-shaped autologous saphenous graft was prepared and introduced through a trocar. For the three anastomoses, a polytetrafluoroethylene running suture was preferred.

Results

The total operation time was 350 min, and the estimated surgical blood loss was about 200 ml. Warm ischemia time was 58 min for the posterior branch and 24 min for the second declamping. The patient resumed a regular diet on postoperative day 2, and the hospital stay lasted 4 days. No intraoperative or postoperative morbidity was noted. A CT scan performed 2 months later revealed the patency of all the reconstructed branches.

Conclusions

The experience of our group counts five other renal aneurysm repair performed with a robot-assisted technique [5]. The presence of five different arterial branches involved in the reconstruction makes this procedure difficult. Robot-assisted laparoscopic technique represents a valid alternative to open surgery in complex cases.     

Renal oncocytoma

Summary A decade has now passed since renal oncocytoma became a diagnosis of acute interest to urologists, radiologists and pathologists. The number of patients with renal oncocytoma continues to increase; now a total of over 340 reported cases are available for analysis. Approximately 3% of tumors previously diagnosed as renal cell carcinomas are now considered to be renal oncocytomas. The overwhelmingly benign clinical behavior of typical renal oncocytomas seems well established. At present, there is no definitive way to make the diagnosis of renal oncocytoma preoperatively. Because renal oncocytomas are not so rare, clinicians dealing with solid renal tumors must keep in mind this diagnosis and its possible bilateral and multifocal occurrence. Conservative renal parenchyma sparing operations for oncocytomas should be encouraged.     

Growth kinetics of renal masses: analysis of a prospective cohort of patients undergoing active surveillance

Background

Active surveillance (AS) represents a treatment option for renal masses in patients who are not surgical candidates either because of existing comorbidities or patient choice. Among renal masses undergoing AS, some grow rapidly and require treatment or progress to metastatic disease. Patient and tumour characteristics related to this more aggressive behaviour have been poorly studied.

Objective

To report the analysis of a multi-institutional cohort of patients undergoing AS for small renal masses.

Design, setting, and participants

This prospective study included 82 patients with 84 renal masses who underwent AS in three Canadian institutions between July 2001 and June 2009.

Intervention

All patients underwent AS for renal masses presumed to be renal cell carcinoma (RCC) as based on diagnostic imaging.

Measurements

Age, sex, symptoms at presentation, maximum diameter at diagnosis (cm), tumour location (central/peripheral), degree of endophytic component (1–100%), and tumour consistency (solid/cystic) were used to develop a predictive model of the tumour growth rate using binary recursive partitioning analysis with a repeated measures outcome.

Results and limitations

With a median follow-up of 36 mo (range: 6–96), the mean annual renal mass growth rate for the entire cohort was 0.25 cm/yr (standard deviation [SD]: 0.49 cm/yr). Only one patient (1.2%) developed metastatic RCC. Amongst all variables, maximum diameter at diagnosis was the only predictor of tumour growth rate, and two distinct growth rates were identified. Masses that are ≥2.45 cm in largest diameter at diagnosis grow faster than smaller masses. This series was limited by its moderate sample size, although it is the largest published prospective series to date.

Conclusions

We confirm that most renal masses grow slowly and carry a low metastatic potential. Tumour size is a predictor of tumour growth rate, with renal masses <2.45 cm growing more slowly than masses >2.45 cm.     

Safety of Contrast Venography prior to Caval Interruption in Patients with Renal Insufficiency

We undertook this study to determine whether the use of contrast venography would adversely affect renal function in patients with renal insufficiency requiring caval interruption. We conducted a retrospective review of all inferior vena cava (IVC) filters inserted at our institution over a 2-year period (January 2002 to January 2004). The indication for caval interruption, insertion technique, type of filter used, pre- and postintervention creatinine level, and the presence of diabetes and hypertension were analyzed. A total of 282 IVC filters were inserted, with 38 of them placed in patients with renal insufficiency as defined by a serum creatinine level of > 1.5 mg/dL. Contrast venography with 15 to 30 mL of iohexol (Omnipaque 300) was used in all cases, and no special measures other than proper hydration were used for renal protection. All filters were successfully deployed. The mean±SD preintervention creatinine level was 2.38±0.79 mg/dL. The mean±SD postintervention creatinine levels at 2 and 30 days were 2.26±0.45 mg/dL and 2.12±0.94 mg/dL, respectively. No patients required hemodialysis following caval interruption, and no adverse effect on renal function was noted. Contrast venography accurately delineates venous anatomy and facilitates proper caval filter placement with no apparent adverse effect on renal function. We believe contrast venography is safe even in the presence of renal insufficiency.     

Paclitaxel in Advanced Urothelial Carcinoma: Its Role in Patients with Renal Insufficiency and as Salvage Therapy

Purpose

We evaluated the role of paclitaxel in patients with advanced urothelial carcinoma and renal insufficiency or as second line therapy for metastatic disease.

Materials and Methods

Nine patients with advanced urothelial carcinoma received 175 to 250 mg./m.² paclitaxel intravenously as a 24-hour infusion. Six patients had renal insufficiency with a median serum creatinine of 2.25 mg./dl. (range 1.9 to 3.2) and 3 with normal renal function were treated after disease progression following 1 to 2 prior chemotherapy regimens.

Results

Of 9 patients 5 (56 percent) achieved a partial response, including 4 to 6 with renal insufficiency. Toxicity was primarily hematological with 4 patients experiencing febrile neutropenia. There was no adverse impact on renal function.

Conclusions

Paclitaxel as a single agent represents an effective therapeutic alternative for patients with advanced transitional cell carcinoma of the urothelium and renal insufficiency precluding cisplatin or gallium nitrate based chemotherapy. Additionally, paclitaxel appears to be effective in patients in whom prior cisplatin based therapy failed.     

Worth a second look: outcomes of patients with initial finding of regular renal tissue in CT-guided renal tumor biopsies

Introduction and objective

Renal tumor biopsy is recommended for histological diagnosis of radiologically indeterminate renal masses, to select patients with small-renal masses for surveillance approaches, before ablative treatments and to confirm metastatic spread of renal cell cancer (RCC), according to the EAU guidelines. We aimed to determine outcomes of patients with suspicious renal masses with initial finding of regular renal tissue in renal tumor biopsies.

Methods

Retrospective database analysis of 101 patients undergoing CT-guided-, percutaneous renal tumor biopsies in local anesthesia.

Results

In 23/101 patients, histopathologic evaluation of the biopsies showed regular renal tissue. Of these, two patients underwent simultaneous radiofrequency ablation (RFA), 2/23 underwent radical nephrectomy, despite negative biopsy because of radiological suspicious aspect. Overall, 12 patients underwent a second set of biopsies due to persistent clinical suspicion. Of these, five were diagnosed with RCC: three clear cell renal cell carcinoma (ccRCC) and two papillary renal cell carcinoma (pRCC). Benign tumours were found in two patients. A lymphoma was found in two patients. In 3/12 patients, also the second set of biopsies showed regular renal tissue.

Conclusion

An unsuspicious histology in CT-guided renal tumor biopsy does not preclude patients with suspicious renal masses from being diagnosed with malignancies.

     

Inhibition of gluconeogenesis and <Emphasis Type="Italic">p</Emphasis>-aminohipuric acid accumulation in rat renal cortical slices by ionic and nonionic contrast media

Background. Renal dysfunction is a well-recognized complication induced by contrast media (CM). Nonionic CM have been introduced into clinical use to replace conventional ionic CM in an effort to reduce toxicity. However, the nephrotoxic effects of nonionic CM have not been fully evaluated. We previously determined the activities of N-acetyl--d-glucosaminidase and -glutamyltransferase released from rat and human renal slices incubated with contrast media. Dose-dependent enzyme release from renal slices was observed, but there was no statistical difference in the increase of enzyme activities between ionic and nonionic CM. The present experiment was conducted to compare the effects of ionic and nonionic CM on the metabolic function of rat renal slices.Methods. Rat renal cortical slices were incubated with ionic CM (diatrizoate, iothalamate) and nonionic CM (iopamidol, iohexol) at 37°C for 90min. To examine the dose–response effects of CM on gluconeogenesis and p-aminohipuric acid (PAH) accumulation in the rat renal slices, slices were incubated with 30, 60, and 90mgI/ml of CM. The inhibitory effects of nonionic CM on gluconeogenesis and PAH accumulation were compared with those of ionic CM in an independent experiment, in which slices were incubated with CM at a concentration of 60mgI/ml. In addition, rat renal slices were incubated with mannitol instead of CM to investigate the effects of osmotic pressure on gluconeogenesis and PAH accumulation.Results. A dose-dependent reduction of gluconeogenesis in rat renal slices was demonstrated by both ionic CM and nonionic CM. The inhibition of PAH accumulation was dose-dependent with nonionic CM, but not with ionic CM. Gluconeogenesis and PAH accumulation within the renal slices were both inhibited according to the increase in osmotic pressure produced by mannitol. The reduction in gluconeogenesis and PAH accumulation within the rat renal slices incubated with 60mgI/ml of nonionic CM were significantly less than those resulting from the same concentration of ionic CM.Conclusions. Nonionic CM is less nephrotoxic than ionic CM with regard to gluconeogenesis and PAH accumulation in rat renal slices. These differences in nephrotoxic effect between ionic and nonionic CM may in part be attributable to differences in osmotic pressure.     

Vitamin C may be beneficial in the prevention of paracetamol-induced renal damage

Background There is no specific treatment for paracetamol-induced renal damage. Vitamin C is an outstanding chain-breaking antioxidant and a free radical scavenger. The present study was undertaken to determine whether large doses of vitamin C are useful in the treatment of paracetamol-induced renal damage.Methods Renal injury was induced in rats by the administration of 1g/kg body weight paracetamol intraperitoneally. Some rats received intraperitoneal injections of vitamin C (250, 500, or 1000mg/kg body wt) at 1.5h, 6h, 9h, or 16h after the administration of paracetamol, and the rats were killed 24h after the administration of paracetamol.Results Renal injury was accompanied by a decrease in nonprotein thiol and protein thiol in the kidneys of paracetamol-treated rats. The administration of vitamin C to the paracetamol-treated rats prevented renal damage either completely or partially. Lower doses of vitamin C were beneficial in the prevention of paracetamol-induced renal injury when administered early and higher doses were beneficial when administered later. In the paracetamol-treated rats that responded to vitamin C, renal nonprotein thiol level and protein thiol were restored almost completely. Interestingly, a highly significant inverse correlation was obtained between renal nonprotein thiol level and plasma creatinine.Conclusions Megadoses of vitamin C may be beneficial in the treatment of paracetamol-induced renal damage. The mechanism of protection by vitamin C appears to be the regeneration of nonprotein thiol.     

Does division of the left renal vein during aortic surgery adversely affect renal function?

Between July 1980 and July 1988, 478 consecutive patients underwent aortic aneurysm operations at Royal Prince Alfred Hospital. Renal function was assessed by measurement of serum creatinine levels. The left renal vein was divided in 28 (8%) of the 355 patients undergoing elective aneurysm resection. The mean immediate postoperative creatinine values were significantly higher after left renal vein division, 193±174 mol/L, compared to 133±93 mol/l for those whose left renal vein remained intact (p < 0.05 by Mann-Whitney U test). After one month, serum creatinine levels had decreased but were still significantly higher in those patients in whom the left renal vein had been divided, 170±166 mol/l, compared to those in whom it was left intact 109±49 mol/l (p<0.05 by Mann-Whitney U test). The suprarenal aorta was cross-clamped in seven (25%) of the 28 patients in whom the left renal vein was divided, compared to 21 (6%) of the 327 with the left renal vein intact. A rise in creatinine level was observed after suprarenal aortic cross-clamping. The left renal vein was divided in 17 (14%) of the 123 patients having emergency surgery for ruptured aortic aneurysm, 61 (49%) of whom survived more than 30 days. The mean immediate postoperative creatinine values were significantly higher after left renal vein division, 426±277 mol/l, compared to those in whom the vein was left intact, 178±136 mol/l (p < 0.05 by Mann-Whitney U test). After one month, serum creatinine levels were still significantly higher in those patients in whom the left renal vein had been divided. Although division of the left renal vein is a useful way to improve exposure of the juxtarenal aorta, the maneuver is associated with an adverse effect on renal function.Presented at the Annual Meeting of the Peripheral Vascular Surgical Society, New York, New York, June, 1989.     

Adult onset Fanconi syndrome: extensive tubulo-interstitial lesions and glomerulopathy in the early stage of Chinese herbs nephropathy

A 33-year-old woman was transferred to our hospital with a 5-month history of taking Chinese herbal medicine containing aristolochic acid. She presented with metabolic acidosis, severe anemia, hypophosphatemia and uric aciduria, and generalized aminoaciduria and glycosuria, features which were consistent with the clinical manifestations of Fanconi syndrome. Renal biopsy was performed when her plasma creatinine was 0.7mg/dl and creatinine clearance was 46ml/min per 1.73m². The renal specimen showed extensive interstitial edema with focal fibrosis, tubular atrophy, and focal glomerulopathy, which suggested the presence of glomerular endothelial damage or glomerular ischemia. Although steroid therapy ameliorated the plasma electrolyte levels, renal failure progressed, and hemodialysis therapy was initiated approximately 18 months after the time of renal biopsy. This patient demonstrated the early renal lesions of Chinese herbs nephropathy in association with various clinical manifestations. The characteristic glomerulopathy found in the present patient is considered to be an additional renal lesion, leading to the renal failure.     

New Renal Scars in Children With Urinary Tract Infections, Vesicoureteral Reflux and Voiding Dysfunction: A Prospective Evaluation

Purpose

Established renal scarring represents areas of the kidney that imaging reveals to be damaged at presentation for medical management of urinary tract infection. New renal scarring represents new renal damage in parts of the kidney that imaging reveals to be normal at presentation. We attempted to characterize patients in whom new renal scars developed while they were under our care.

Materials and Methods

In 1988 a data base was started to identify patients with new renal scarring. All patients presenting with urinary tract infections were enrolled. Our data base has 250 possible fields per event with multiple events per patient. More than 2,100 patients have been enrolled to date. All patients with pyelonephritis, defined as a febrile urinary tract infection with flank pain and tenderness, and all with reflux underwent dimercapto-succinic acid (DMSA) scan at least 4 months after presenting with infection to assess established renal scars. New renal scars were identified when new renal defects were demonstrated on a second DMSA scan.

Results

In our data base there are 1,426 patients with urinary tract infections, 685 (46%) with pyelonephritis and 1,062 (74.5%) with vesicoureteral reflux, including 558 found to have bilateral vesicoureteral reflux and 504 diagnosed with unilateral reflux. A history of daytime urinary incontinence was noted in 538 patients (37.7%), 192 (13.5%) had established scars at initial presentation and in 31 (2.1%) new renal scars developed while they were under our care, including 30 with established scars as well. Of the 25 patients in whom new renal scars developed while on medical therapy 11 underwent surgery. In 6 patients with dysfunctional voiding who were receiving medical treatment renal scars developed postoperatively. Surgery was performed in 17 of the 31 patients and 24 (77%) with new renal scars had a history of dysfunctional voiding.

Conclusions

Previous characterizations of patients with new renal scars have relied on excretory urography for assessing renal architecture and ignored voiding patterns of the children affected. Using the DMSA scan we identified 31 children with reflux, urinary tract infection and dysfunctional voiding in whom new renal scars developed while they were under our care.