Enucleation procedures in patients with multiple hereditary renal tumors

Summary Parenchymal sparing surgery is frequently appropriate in patients with familial renal tumors detected through the screening of affected kindreds. An enucleation technique for the rapid removal and hemostasis of multiple small renal tumors in patients with hereditary renal cancers is described herein. This technique facilitates the removal of multiple small superficial renal tumors, usually without hypothermia.     

Parenchymal sparing surgery for central renal tumors in patients with hereditary renal cancers

PURPOSE: Nephron sparing surgery has become accepted surgical practice for removing of renal tumors. The resection of central lesions has been thought to be more surgically challenging than that of peripheral tumors. We analyzed our experience with renal preservation surgery in patients with small hereditary central renal tumors. MATERIALS AND METHODS: From 1992 to 2000 we performed 116 partial nephrectomies with 44 kidneys (38%) demonstrating central renal masses. Central renal tumors were defined radiologically as those completely encircled by parenchyma or transgressing the interpapillary line on computerized tomography. We compared this group to a similar series of 67 patients with hereditary renal cancer with only peripheral based tumors. RESULTS: Mean tumor size was 3.2 cm (range 1.5 to 7.5). Mean operative time was 352 minutes (range 70 to 830). Renal hypothermia and vascular clamping were used in 19 of 44 procedures (41%). Mean ischemic time was 55 minutes (range 16 to 143). Mean blood loss was 4.6 l (range 0.1 to 23). The complication rate was 23% (10 of 44 cases) and with 18% (8 of 44) directly related to surgical technique. The mean transfusion requirement was 6.7 U (range 0 to 32) and 12 of 44 procedures (27%) required no blood products. Mean preoperative and postoperative serum creatinine was 1.05 (range 0.6 to 1.8) and 1.08 mg/dl (range 0.6 to 2.1), respectively. Mean followup was 33.7 months. No metastasis developed during followup. CONCLUSIONS: Central renal tumors are a common manifestation of hereditary renal cell carcinoma. There was no statistical difference found between common operative parameters when central and peripheral nephron sparing surgeries were compared. However, mean operative blood loss and transfusion requirements were increased in the central tumor group.     

Behavior of amikacin in renal parenchyma of normal rats and of rats with acute obstructive renal insufficiency

Aminoglycosides show a remarkable tendency to accumulate and persist in the renal parenchyma. In order to study the kinetics of this phenomenon for amikacin, rats received 25 mg/kg of this antibiotic i. p. and were sacrificed in groups of 6 up to 15 days after the injection. At 6 h, while the other organs and the serum were almost completely freed of amikacin, concentrations in the renal cortex reached 156 +/- 21 micrograms/g, or 6 times the peak serum level (instead of 20 times the peak serum level for gentamicin or sisomicin, a difference which is reduced by the fact that amikacin is given in higher dosage). They then decreased very slowly, according to a half-life of 122 h. Although it decreases glomerular filtration, ligation of ureters 20 h before the injection quadrupled the concentration in the cortex. These data explain the characteristics of the nephrotoxicity of amikacin and the increased toxic risk in acute obstructive renal insufficiency.     

Clinico-pathological investigation of upper urinary tract tumors in patients with normal renal function and in patients with end stage renal disease

AIMS: To clinically investigate upper urinary tract tumors in end stage renal disease (ESRD) patients. PATIENTS AND METHODS: Between 1988 and 2003, a study was made of 153 patients who underwent surgical treatment for upper urinary tract tumors in the Department of Urology, Tokyo Women's Medical University. Of these, 10 had ESRD while 143 had normal renal function. Comparisons were made of the following variables between the two groups: patient's background, clinical findings, surgical procedures, pathological findings, prognosis, depth of tumor cell invasion, tumor grades, postoperative survival rates, cancer-specific survival rates, and complications. RESULTS: Ten ESRD patients with upper urinary tract tumors were comprised of 5 males and 5 females with a median age of 59 (40-71) years and an average hemodialysis period of 71 (0-279) months. Macroscopic hematuria appeared in seven cases (70%) at the onset, and tumors occurred at the renal pelvis in nine cases (90%). As to the T stage, seven cases (70%) were pT2 or more and all 10 cases (100%) exhibited grade 2 or higher in ESRD patients, yielding no significant differences with the cases of normal renal function. In addition, there was no significant difference in both groups with respect to postoperative survival rates and cancer-specific survival rates in cases with curative resection. CONCLUSION: Although upper urinary tract tumors had been considered to exhibit higher grades and stages of malignancy in ESRD cases than in those with normal renal function, the present results showed that the clinico-pathological features are similar in both patients groups. Given that there was no significant difference in postoperative survival rates and cancer-specific survival rates, radical surgery should be also indicated, if possible, for the ESRD patients with upper urinary tract tumors as well as the patients with normal renal function.     

Oliguria in patients with normal renal function

Oliguria is common in critically ill patients and may result from prerenal, renal, and postrenal causes. Oliguria also frequently develops in patients with normal concentrations of blood urea nitrogen and creatinine. Most of these patients do not develop renal failure. The authors prospectively studied 100 patients admitted to the ICU to determine the etiology of oliguria in these patients. Eighteen patients (18%) developed oliguria (less than 0.33 ml.kg-1.h-1 X 2 h). Seven and eleven patients were felt on clinical assessment to be hypovolemic or normovolemic, respectively. Compared with the hypovolemic patients, the normovolemic oliguric patients had significantly lower serum osmolalities (278 +/- 3 vs. 290 +/- 5 mOsm/kg H2O) and serum sodium concentrations (138 +/- 3 vs. 132 +/- 1 mEq/l). In addition, normovolemic patients had significantly higher urine sodium concentrations (83 +/- 12 vs. 13 +/- 2 mEq/l), fractional excretion of sodium (1.14 +/- 0.2 vs. 0.15 +/- 0.03), and renal failure indices (1.5 +/- 0.3 vs. 0.21 +/- 0.04). ADH concentrations in six hypovolemic and six normovolemic patients were increased in both groups but not significantly different. The hypovolemic patients increased their urine output from 17 +/- 2 ml/h to greater than 0.5 ml.kg-1.h-1 following a 500-ml bolus of normal saline. The normovolemic oliguric patients remained oliguric following the saline bolus (13 +/- 2 to 19 +/- 3 ml/h). The authors conclude that oliguria is common in critically ill patients and results from renal hypoperfusion and ADH excess.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous renal cryoablation of renal tumors in patients with von Hippel-Lindau disease

PURPOSE: We determine the feasibility and safety of performing percutaneous cryoablation of renal tumors in patients with von Hippel-Lindau disease. MATERIALS AND METHODS: We selected 2 men and 2 women with von Hippel-Lindau disease and radiographic determined solid renal tumors were selected to undergo percutaneous cryoablation. All patients underwent standard preoperative evaluation. An interventional magnetic resonance imaging unit was used for probe guidance and ice ball monitoring. The cryoablation procedure was performed with a 2 or 3 mm. cryoprobe using a pressurized argon gas system for ice ball formation. The patients were hospitalized overnight for observation and discharged home the following day. A followup computerized tomogram or magnetic resonance imaging scan was performed at 1 week, 1, 3, 6 and 12 months and every 6 months thereafter, along with physical examination, urinalysis, serum blood urea nitrogen and creatinine. RESULTS: A total of 5 tumors were treated ranging from 2.8 to 5.0 cm. in diameter. All patients underwent the procedure without difficulty with 2 requiring re-treatment due to residual tumor for a total of 7 treatments. At followup from 2 to 23 months there has been no radiographic evidence of recurrence at the cryoablated areas. CONCLUSIONS: Percutaneous cryoablation of renal tumors in patients with von Hippel-Lindau disease proved to be successful in this initial series. Although 2 patients had residual tumor after the initial cryoablation procedure re-treatment was performed with no adverse sequela. This minimally invasive therapy may allow patients with von Hippel-Lindau disease to avoid the necessity of multiple open surgical procedures.     

Prevalence of ischemic nephropathy in patients with renal insufficiency.

To estimate its clinically unsuspected prevalence among patients with renal insufficiency, renal duplex sonography (RDS) was used to estimate the presence of critical renal artery stenosis (RAS) in that population. Patients, aged 45 to 75 years, with a serum creatinine of greater than or equal to 2.0 mg% but without dialysis dependence, prior renal transplantation, or prior renal artery surgery were considered for RDS. Fifty-three patients who met criteria for study were randomly selected from the Section of Nephrology clinic files and each patient was contacted both by mail and by telephone. Twenty-five patients agreed to RDS, and renal artery anatomy was determined in 21 patients using standardized RDS techniques. These techniques have demonstrated an overall accuracy of 96 and 97 per cent when compared prospectively to conventional angiography during validity analyses in the authors' center. Results of RDS revealed significant findings in 5 of 21 patients (24%). Three patients demonstrated criteria for ischemic nephropathy (IN): one patient had RAS with contralateral renal artery occlusion confirmed by angiography, while 2 patients demonstrated unilateral RAS. An abdominal aortic aneurysm and unilateral hydronephrosis were discovered in the fourth and fifth patients. Evaluation of patient demographic data and functional parameters as predictors of IN revealed that the duration of renal insufficiency at the time of RDS and extra-renal organ-specific atherosclerotic damage were significantly different between the groups with and without IN. The authors preliminary findings suggest that unsuspected ischemic nephropathy may exist in a significant minority of patients with renal insufficiency.     

Prevalence of Helicobacter pylori in patients with chronic renal failure

The prevalence of Helicobacter pylori (H. pylori) was investigatedin 164 consecutive patients with different degrees of renalfunction; group I (normal renal function) n=84, group II (chronicrenal failure, CL_CR 5<90 ml/min) n=45, group III (haemodialysistherapy) n=35, to test the hypothesis that the resulting differentconcentrations of urea in the gastric juice would have an influenceon the colonization of the gastric mucosa by these urea-splittingbacteria. As every individual method for the detection of H.pylori shows disadvantages, the results of the detection methodsused (urease test, Warthin-Starry stain, bacterial cultivation,direct examination of the processed sample by phase-contrastmicroscopy) were combined in a cumulative evaluation. Thesecalculated cumulative indices for the antrum and corpus showedno statistically significant differences between the studiedgroups. The prevalence of H. pylori ranged from 34 to 54%. Thehistopathological findings were similar in all groups. In spiteof the fact that patients with renal dysfunction had significantlyhigher levels of serum gastrin (P<0.05), there was no influenceon the gastric juice pH value. The relationship between thecumulative index and ammonia concentration in gastric juicewas found to be linear (P<0.05). The higher urea levels inthe blood and gastric juice of patients with renal failure donot seem to be a risk factor for infection with H. pylori.     

Conversion to sirolimus in renal transplant patients with tumors

BACKGROUND: Conversion from calcineurin inhibitors (CNI) to sirolimus (SRL) is an option for renal transplant patients who develop a tumor. This strategy, however, may be associated with an increased risk of rejection. AIM: We sought to evaluate a series of renal transplant patients who underwent conversion from CNI to SRL because they developed a tumor during the posttransplant period. METHODS: This prospective study of 29 patients included 2 patients with skin cancer (1 melanoma and 1 squamous cell carcinoma) and 27 patients who developed other tumors: lung (n = 6), prostate (n = 4), lymphoma (n = 2), colon adenocarcinoma (n = 2), kidney (n = 2), Kaposi sarcoma (n = 2), urothelium (n = 1), parotid (n = 1), larynx (n = 1), gastric (n = 1), breast (n = 1), tongue (n = 1), liver (n = 1), xanthoastrocytoma (n = 1), and aggressive angiomyxoma of the perineum (n = 1). RESULTS: CNI were withdrawn in 28 patients and reduced in the remaining patient. Renal function was better when CNI were rapidly or abruptly suspended, with maintenance of cyclosporine (CsA) + SRL for more than 3 months being especially detrimental. Proteinuria worsened in patients whose preconversion levels were >0.5 g/d, particularly those treated with CsA. There was no episode of rejection. CONCLUSIONS: SRL is a promising option for the management of posttransplant tumors. The switch in immunosuppression should be undertaken quickly, especially in patients under treatment with CsA.     

Detection and significance of microscopic hematuria in patients with blunt renal trauma

Detection of hematuria is paramount in establishing injury to the urinary system. In 339 patients with blunt renal trauma in whom radiographic studies defined the severity of injury we compared the degree of microscopic hematuria determined by dipstick and microscopic urinalysis. The overall correlation between the 2 methods was low (Pearson's coefficient 0.41). However, more than 80 per cent of the urine samples with 50 to 100 red blood cells per high power field corresponded to a dipstick result of 3+. The dipstick method had greater than 97.5 per cent sensitivity and specificity for detection of microscopic hematuria. Only 7 of the 339 patients (less than 2 per cent) had a discharge diagnosis of other than renal contusion: 5 had renal artery thrombosis or avulsion of the renal vessels and 2 had minor cortical lacerations that were managed nonoperatively. Although microscopic hematuria may be quantified more accurately by microscopic analysis, it can be detected reliably with a high degree of sensitivity and specificity by dipstick analysis.