The pulsatility index and the resistive index in renal arteries in patients with hypertension and chronic renal failure

BACKGROUND.: The pulsatility index (PI) and the resistive index (RI) areused as pulsed-wave Doppler measurement of downstream renalartery resistance. Little information is available on theirvalue in chronic renal failure and their correlation to parametersof renal function and haemodynamics. The aim was to comparePI and RI of renal arteries in healthy volunteers and in patientswith hypertension and chronic renal failure, and furthermoreto study the correlation of these indices to measurements ofrenal haemodynamics and function by standard methods in patientswith renal failure and hypertension. METHODS.: Twenty-five hypertensive patients (10 females, 15 males, meanage 52 years (24–74) with a glomerular filtration rate(GFR) less than 50 ml/min and an arterial blood pressure above140 mmHg systolic and 95 mmHg diastolic were included in thestudy. Ten healthy, normotensive volunteers (4 females and 6males, mean age 43 years (30–62)) served as controls inthe Doppler examinations. Doppler examinations were performedin segmental arteries by an Acuson 128. The PI and the RI wascalculated from the blood flow velocities. RESULTS.: Both the PI and the RI were significantly higher in the patientgroup (P) than in the control group (C) (PI, P 1.65 (1.31–1.86),C 1.19 (0.93–1.25), P=0.003; RI, P 0.76 (0.69–0.81),C 0.67 (0.64–0.70), P=0.003). Both PI and RI correlated significantly with effective renalplasma flow (PI: r= –0.5, P=0.02; RI: r=–0.5, P=0.006),renal vascular resistance (PI: r=0.4, P= 0.05; RI: r=0.5, P=0.02),filtration fraction (PI: r=0.6, P=0.005; RI: r=0.5, P=0.01)and clearance of creatinine (PI: r=–0.6, P=0.008; RI:r=–;0.6, P= 0.006). Only RI correlated significantly toGFR (r=–0.5, P=0.02). The indices did not correlate toserum creatinine, or mean arterial blood pressure. CONCLUSION.: PI and RI seems to be closely related to parameters of renalhaemodynamics and clearance of creatinine in patients with chronicrenal failure and hypertension.     

Prevalence of atherosclerotic renal artery stenosis in patients starting dialysis.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) can lead to end-stage renal failure (ESRF). We determined the prevalence of ARAS in patients 45 years of age or older starting renal replacement therapy. METHODS: Forty-nine of 80 consecutive patients (37 males, 12 females) starting renal replacement therapy in our centre gave informed consent and underwent spiral computed tomographic angiography of their renal arteries. A renal artery diameter reduction of 50% or more assessed by two radiologists was considered as a significant stenosis. RESULTS: Twenty of 49 patients (41%) had an ARAS, and in eight cases (16%) this was bilateral or unilateral with a single kidney. Women were more likely to have an ARAS than men; 75 (9/12) vs 30% (11/37, P<0.01). However, relatively more women declined participation. Non-participants and participants did not differ in respect to other relevant clinical data. Nonetheless, findings in these patients would be negative, the prevalence of ARAS would still be 31% in women and 22% in men (NS). In 13 patients with ARAS the registered diagnosis of ESRF either was hypertension, renovascular disease or unknown. Assuming that in these patients atherosclerotic renovascular disease was the cause of renal failure, a total of 13 patients (13/49, 27%) entered the dialysis programme because of this problem. CONCLUSIONS: These results suggest that ARAS is an important cause of ESRF.     

Incidental neoplasms in renal biopsies.

BACKGROUND: Incidental neoplastic lesions are occasionally found in renal biopsy specimens, but there is no evidence to indicate how they should be managed. METHODS: A retrospective review was made of the management and clinical course of patients in whom an unsuspected neoplasm had been found in a renal biopsy. RESULTS: In 11 880 biopsies taken over 22 years, there were incidental neoplasms in 25 (0.2%). Twenty-three of the 25 patients were men, and the median age was 59 years (range, 42-83 years). All had chronic renal damage, with a median index of chronic damage of 37% (range, 10-83%; normal=0%). Twenty-two neoplasms were papillary, two were clear cell renal carcinomas and one was in situ carcinoma in a collecting duct. The two clear cell carcinomas, three papillary neoplasms with residual masses after biopsy and the two papillary neoplasms in renal allografts were resected by nephrectomy or partial nephrectomy. Seven patients without resection were imaged with computerized tomography, six with magnetic resonance imaging and three with ultrasound scanning. Two were not imaged. None of the 11 patients who died, nor any of the other 14, had evidence of renal cell carcinoma at death or last follow-up respectively, at median 3.6 years after biopsy (range, 1 month-18.2 years). CONCLUSIONS: When an incidental neoplasm is found, the pathological type should be defined, and imaging should be performed. Surgery should be considered in patients in whom there is a neoplasm of any type detectable by imaging, and limited resection may be possible. Neoplasms that are undetectable with imaging cannot be resected as the site of the lesion is unknown. We suggest surveillance of these, but whether this is necessary is undetermined. There is no evidence whether neoplasms undetectable with imaging in renal allografts require aggressive treatment.     

益肾泄浊方对痛风性肾病并发慢性肾衰竭大鼠肾功能及病理影响的实验研究

目的:观察益肾泄浊方对痛风性肾病并发慢性肾衰竭大鼠模型血清尿素氮、肌酐、尿酸的影响及肾脏病理组织学变化的影响。方法:将大鼠随机分组处理:模型组予高酵母饲料喂养及腺嘌呤灌胃,建立痛风性肾病并发慢性肾衰竭大鼠模型;同时分别以别嘌醇、益肾泄浊方干预;正常对照组给予普通大鼠颗粒饲料喂养,生理盐水灌胃。监测大鼠血清尿酸、肌酐及尿素氮水平的变化,同时观察大鼠肾脏病理改变。结果:与正常对照组比,第5周末模型组大鼠尿素氮、血肌酐、血尿酸增高,P<0.05,肾脏病理为痛风性肾病并发慢性肾衰竭大鼠模型改变;与模型组比较,别嘌醇组血尿酸明显下降,P<0.05;益肾泄浊方大剂量组血肌酐下降明显,P<0.05;益肾泄浊方大剂量组病理修复最好,别嘌醇组次之。结论:益肾泄浊方可以保护痛风性肾病并发慢性肾衰竭大鼠肾功能、修复肾脏病理。     

Pamidronate used to attenuate post-renal transplant bone loss is not associated with renal dysfunction.

BACKGROUND: Pamidronate is a second-generation bisphosphonate that has been used to attenuate post-renal transplant bone loss, but its effect on the function of the renal allograft is unclear. Therefore, we evaluated the long-term renal function in 57 subjects who had participated in a prospective, randomized clinical trial using pamidronate to attenuate bone loss in the renal transplant recipient. METHODS: Thirty subjects (PAM) received intravenous pamidronate, 60 mg at baseline post-transplant and 30 mg in months 1, 2, 3 and 6 post-transplant, while 27 subjects (CON) did not receive pamidronate. We followed renal function, need for renal replacement therapy following transplant rejection, and mortality for 3 years following the start of the original study. RESULTS: PAM did not have increased incidence of renal dysfunction or mortality compared with CON at any time point during the 3 years of follow-up. The incidence of proteinuria was also not different between the two groups. CONCLUSIONS: The prophylactic use of pamidronate in the above doses to attenuate bone loss in renal transplant recipients is not associated with higher incidence of renal dysfunction or mortality in a 3 year follow-up study. These findings may support the use of bisphosphonates in the treatment of early renal transplant-related bone loss.     

Pathogenesis and management of hyperparathyroidism in end-stage renal disease and after renal transplantation

SUMMARY: Secondary hyperparathyroidism is an adaptive response to progressive loss of renal function so as to maintain calcium and phosphate homeostasis, 1,25-dihydroxyvitamin D₃ levels and normal bone turnover, despite skeletal resistance to parathyroid hormone. As feedback regulation fails, complications of parathyroid overactivity develop, and by the commencement of dialysis abnormal bone histology is present in almost all patients, with hyperparathyroid changes most commonly found. Post transplantation, persisting hyperparathyroidism predisposes to osteoporosis. The risk of bone disease is reduced by early, carefully targeted dietary measures and suppressive therapy with calcitriol and calcium-based phosphate binders, while newer therapies include bisphosphonates and calcimimetics. Timely surgical intervention is necessary in some patients.     

The Spectrum of Adult Postinfectious Glomerulonephritis in the New Millennium

Background. Postinfectious glomerulonephritis is rare in adults. The characteristics of the disease now differ from what were described decades ago. The goal of this study is to illustrate the clinicopathological spectrum of the disease in the modern era. Methods. Between July 2000 and June 2008, 20 adult cases of postinfectious glomerulonephritis were identified at a medical center in Taiwan. The patients' records were retrospectively reviewed with respect to clinical presentation, microbiology, serology, morphology of renal biopsy, and clinical course. Results. There were 14 males and 6 females. The mean age was 61 years. All patients developed acute renal failure, and the majority (65%) required dialysis support during the disease course. Hypocomplementemia was present in 60% of patients. The most frequently identified infectious agent was Staphylococcus (60%). Histological characteristics showed two distinct patterns of glomerulonephritis: diffuse endocapillary proliferative glomerulonephritis (65%) and focal mesangial proliferative glomerulonephritis (35%). There were no significant differences in the clinical presentation and outcome between the two groups. However, glomerular neutrophil infiltration was more commonly present in diffuse endocapillary proliferative pattern (p = 0.017). The percentage of patients with focal mesangial proliferative pattern significantly increased over time (p < 0.001). At the last follow-up, 6 patients (30%) had died, 6 (30%) were in complete remission, 4 (20%) had partial remission with renal insufficiency, and 4 (20%) were on chronic dialysis. Conclusions. Our data suggested that Staphylococcus had become the leading pathogen in adult postinfectious glomerulonephritis over the past 10 years. Furthermore, atypical histological feature with focal mesangial proliferative pattern was increasingly identified over time. The prognosis was still guarded, carrying a considerable mortality rate and risk for developing chronic renal failure.     

UPPER URINARY TRACT TUMOURS IN HONG KONG (1972–1987)

A retrospective analysis of all primary upper urinary tract tumours (300) filed in the pathology department of a regional hospital in Hong Kong during 1972–87 showed that renal cell carcinoma (143) was the commonest malignant tumour. Transitional cell carcinoma of the renal pelvis (62) was the next most frequent. Fibromas, which occurred as frequently as angiomyolipomas (28) and outnumbered tumours such as squamous cell carcinoma (13) and nephroblastoma (12), were little clinical significance since they were invariably incidental findings. Nephrectomies were seldom performed for kidneys involved in secondary malignancies. Rare tumours encountered were adenocarcinonia of the renal pelvis, leiomyosarcoma, malignant fibrous histiocytoma, adenoma, oncocytoma, mesoblastic nephroma and multilocular cystic nephroma. Angiomyolipomas were responsible for most cases of surgical emergency.     

The use of the hypogastric artery in the anastomosis of multiple renal arteries in the transplant patient

Abstract. Alternative techniques for handling multiple renal vessels in living related kidney transplants by use of the hypogastric artery are presented. This vessel can be used either as a tubular vascular graft or as a Carrel patch graft. Details of these techniques are discussed.     

Laparoscopic renal biopsy: a 9-year experience

OBJECTIVES: To present our experience and outcome of consecutive laparoscopic renal biopsy over a 9-year period, as renal biopsy remains an important diagnostic procedure for evaluating proteinuria, haematuria and renal failure, but when percutaneous biopsy is contraindicated, a laparoscopic biopsy is an attractive option because it is minimally invasive. PATIENTS AND METHODS: Seventy-four patients (29 male, 45 female, mean age 45 years, range 3-79) had a laparoscopic renal biopsy taken for various indications, e.g. morbid obesity, solitary kidney, coagulopathy, failed percutaneous biopsy, high location of the kidney and poor visualization with ultrasonography. The kidney was approached via a laparoscopic retroperitoneal route using a two-port technique, with the patient in the flank position. After identifying the kidney, one to five cortical biopsies were obtained with cup-biopsy forceps. RESULTS: Adequate tissue was obtained in 96% of the patients; the mean (range) operative duration was 123 (9-261) min and the estimated blood loss 67 (5-2000) mL. Forty-three patients were discharged within 24 h. Complications occurred in 10 patients, with significant bleeding in three. One patient died after surgery, secondary to a perforated peptic ulcer while on high-dose steroid therapy. CONCLUSION: Laparoscopic renal biopsy is a safe and effective alternative to open renal biopsy for patients in whom percutaneous biopsy is not feasible. It offers the advantage of obtaining cortical biopsies and achieving haemostasis under direct vision. Adequate renal tissue is obtained in most cases. Recovery and convalescence are short for most patients.     

Angiographic visualization for percutaneous renal biopsy

Fifteen patients underwent visualization of the kidney for percutaneous biopsy by selective renal angiography. Biopsies were performed in 11 patients, and adequate renal tissue was obtained in all instances. Postbiopsy angiogram revealed pinpoint bleeding in ten patients and significant extravasation in one case, which was controlled with a selective epinephrine infusion. In four cases, biopsy was not performed when the cortex was found to be less than 5 mm thick.     

Renal tumors: The good, the bad, and the ugly

Renal cancers comprise a wide variety of neoplasms with quite different genetic and molecular characteristics and clinical behaviors. Several issues of significant note have arisen in association with our increased understanding of these tumors, including questions regarding early diagnosis, the evaluation of cystic lesions, the behavior of tumors occurring in young patients, and insights regarding the prognosis and best follow-up strategies for these tumors.     

Renal Ischemic Injury Affects Renal Hemodynamics and Excretory Functions in Sprague Dawley Rats: Involvement of Renal Sympathetic Tone

The role of renal sympathetic nerves in the pathogenesis of ischemic acute renal failure (ARF) and the immediate changes in the renal excretory functions following renal ischemia were investigated. Two groups of male Sprague Dawley (SD) rats were anesthetized (pentobarbitone sodium, 60 mg kg^?1 i.p.) and subjected to unilateral renal ischemia by clamping the left renal artery for 30 min followed by reperfusion. In group 1, the renal nerves were electrically stimulated and the responses in the renal blood flow (RBF) and renal vascular resistance (RVR) were recorded, while group 2 was used to study the early changes in the renal functions following renal ischemia. In post-ischemic animals, basal RBF and the renal vasoconstrictor reperfusion to renal nerve stimulation (RNS) were significantly lower (all p < 0.05 vs. control). Mean arterial pressure (MAP), basal RVR, urine flow rate (UFR), absolute and fractional excretions of sodium (U_NaV and FE_Na), and potassium (U_KV and FE_K) were higher in ARF rats (all p < 0.05 vs. control). Post-ischemic animals showed markedly lower glomerular filtration rate (GFR) (p < 0.05 vs. control). No appreciable differences were observed in urinary sodium to potassium ratio (U_Na/U_K) during the early reperfusion phase of renal ischemia (p > 0.05 vs. control). The data suggest an immediate involvement of renal sympathetic nerve action in the pathogenesis of ischemic ARF primarily through altered renal hemodynamics. Diuresis, natriuresis, and kaliuresis due to impaired renal tubular functions are typical responses to renal ischemia and of comparable magnitudes.     

Renal Adenoma Associated with Renal Cyst Formation

We report a renal adenoma associated with renal cyst formation in a 49-year-old male. A small renal mass inside a right renal cyst was discovered incidentally by ultrasonography. A right nephrectomy was performed. A pathologic examination revealed a well-differentiated, benign papillary tumor which was composed of slightly eosinophilic cells. We therefore diagnosed this patient as having a renal adenoma with hemorrhage.     

特发性肾出血36例诊治分析

目的：探讨特发性肾出血的诊断与治疗,提高其诊治水平。方法：回顾性分析2000年1月～2010年8月我科收治的特发性肾出血36例。结果：36例患者中肾动静脉瘘28例,微小肾盂及。肾盏癌4例,肾动脉瘤3例,肾假性动脉瘤1例。其中29例行选择性肾动脉栓塞术,2例行肾切除术,4例行肾盂癌根治术,所有治疗后患者血尿均消失;1例因肾动静脉瘘多处,未进行治疗。结论：外科常见的特发性肾出血病例以肾血管疾病最为常见,选择性肾动脉造影及肾动脉栓塞术对特发性肾出血的诊治有重要意义。对于难以确诊的特发性肾出血患者,要考虑到微小肾盂肾盏癌的可能,输尿管软镜检查对其诊断有一定帮助。     

Isolated hydatid disease of the native kidney in a renal transplant recipient.

A 43-year-old male renal allograft recipient was admitted tothe hospital for annual check-up. He received a cadaveric renaltransplant 2 years previously. On admission his physical examinationdid not show any abnormalities. Abdominal ultrasonography ofthe patient revealed     

Renal Oncocytoma in Taiwan

Background. Renal oncocytoma has been repeatedly reported in Western countries, but only a few cases have been reported in Eastern countries. This study aims to review the clinical course of renal oncocytoma in an Eastern country such as Taiwan. Materials and Methods. Sixteen cases of renal oncocytoma seen between 1987 and 2002 at Chang Gung Memorial Hospital, Taipei, Taiwan, were studied. Results. Preoperatively, all patients were diagnosed to have renal cell carcinoma, following various radiologic studies. Perioperatively, frozen sections of three patients indicated renal oncocytoma in two and renal cell carcinoma in one. Renal oncocytoma has marked similarities to renal cell carcinoma, according to various radiologic, cytologic, and pathological investigations, so an accurate diagnosis is difficult to achieve, either preoperatively or perioperatively. Therefore, rather than being treated with partial nephrectomy, all patients were treated aggressively with unilateral radical nephrectomy. Postoperatively, all 16 patients were followed up, from 12 to 189 months, with a mean of 58.7 months. Notably, all patients survived with no evidence of tumor recurrence. Conclusions. The experience in Taiwan is generally that renal oncocytoma behaves benignly, as reported in other areas. The excellent prognosis associated with this tumor appears to indicate that partial nephrectomy may suffice for removing the tumor, while sparing other unaffected renal parenchyma.