[An unusual cause of ureteral obstruction in kidney transplant]. / Una causa non usuale di ostruzione ureterale nel trapianto renale.

Inguinal herniation of the ureter in a kidney transplantation is a rare cause of late distal ureteral obstruction. Herniation is usually secondary to the implant of a long redundant ureter and to its course on the spermatic cord. This clinical condition can worsen graft function in the presence of ipsilateral hydroureteronephrosis. In this review, we describe the case of an asymptomatic 51-year-old man with a history of right iliac renal allotransplantation 12 years before. Kidney ultrasound showed moderate hydroureteronephrosis and ureteral kneeling at the upper third of the inguinal canal. The patient presented a mild increase in serum creatinine; physical examination revealed an ipsilateral inguinal hernia. A CT scan of the abdomen with no contrast medium confirmed middle-distal ureteral kneeling engaging in the sac of the right inguinal hernia. The patient underwent surgical hernia repair with no complications and his renal function recovered completely.

[Rescue endovascular revascularization in two patients with bilateral atherosclerotic renal artery occlusion]. / Rivascolarizzazione endovascolare di salvataggio in due pazienti con occlusione aterosclerotica bilaterale dell'arteria renale.

Renal artery stenosis is found in 2% and 40% of general and high cardiovascular risk populations, respectively. Atherosclerotic renal artery stenosis (ARAS) has become an increasingly recognized clinical condition, especially in older or otherwise atherosclerosis-prone populations. This increase in prevalence has led to a dramatically increased use of percutaneous transluminal renal angioplasty. Randomized trials have failed to demonstrate any superiority of renal revascularization over medical therapy as far as control of hypertension, mortality or cardiovascular events is concerned. However, in this report we present two cases in which rescue endovascular revascularization in patients affected by bilateral ARAS permitted withdrawal from hemodialysis treatment and the restoration of a certain degree of renal function. In conclusion, for certain carefully-selected high-risk patients, renal revascularization may still have an important role. The two cases presented in this article are good examples of the extraordinary benefit that endovascular revascularization can bestow.

Fibromuscular dysplasia of renal arteries presenting with bilateral renal infarction in a young man.

Fibromuscular dysplasia (FMD) describes a group of conditions which cause nonatheromatous arterial stenoses, most commonly of the renal and carotid arteries, typically in young women. We report the case of a previously healthy 43-year-old white man presenting with acute bilateral flank pain. The pain was more severe on the left side. Initially treated for ureteral colic, he was transferred to the nephrology unit upon recognition of a rising serum creatinine. He was found to have FMD of bilateral renal arteries with resultant infarctions in both kidneys. He was treated with intravenous heparin and, then, warfarin at discharge. At a 16-month review, the patient remained pain-free with normal renal function and with antiplatelet and dual antihypertensive therapy. In conclusion, renal infarction complicating FMD is rare, with most cases involving causative cardiovascular risk factors, including coagulopathy, ischemic heart disease, atrial fibrillation or structural cardiac abnormalities, none of which was present in this case. What makes this case interesting are the clinically significant bilateral renal infarctions due to atypical asymmetric FMD in both kidneys in a young man.

The systemic capillary leak syndrome: a scarcely known nephrological entity.

The idiopathic systemic capillary leak syndrome (SCLS) is a rare life-threatening disorder characterized by periodic episodes of hypovolemic shock, due to plasma leakage from the intravascular to the interstitial space, as reflected by accompanying hypoalbuminemia, hemoconcentration and edema. Here we report the case of a 65-year-old woman affected by SCLS who required aggressive resuscitation with norepinephrine, steroids, albumin and crystalloids. Then, a long-term prophylaxis with a ß(2)-adrenergic receptor agonist and theophylline was started. In conclusion, though SCLS is a rare entity, the associated morbidity and mortality require the physician's awareness to provide timely therapy. Underrecognition in the medical community and rarity of this syndrome have precluded analysis by rational clinical trial designs that are necessary to determine more targeted and adequate therapy. This report is meant to enhance awareness of SCLS in the nephrology community.

Is there a link between the late occurrence of a brachial artery aneurysm and the ligation of an arteriovenous fistula?

Arteriomegaly and aneurysms proximal to long-standing posttraumatic arteriovenous fistulas (AVF) have been described. Much fewer are the reports of the late occurrence of brachial artery aneurysms following the closure of a hemodialysis AVF. Here, we report the case of a 55-year-old male patient. He had received a cadaver donor kidney transplant in 1996; his distal radiocephalic (RC) wrist AVF in the left arm had been ligated in 2001; he developed an aneurysm of the left brachial artery 9 years after the ligation of the AVF (2009). He underwent the surgical intervention of aneurysmectomy at the level of the left brachial artery with construction of a bypass with autologous saphenous vein. In conclusion, the development of a RC wrist AVF is an intrinsically dynamic process characterized by the increase in both blood flow rate and internal diameter of the brachial artery; the latter might be associated with enhanced fracture of the elastic fibers with the consequent risk of the development of an aneurysm. Thus, arteriomegaly and aneurysm of the brachial artery proximal to long-standing AVFs might be seen as a "continuum" of these morphologic modifications.

Autogenous side-to-side brachial-basilic fistulas without vein transposition: a valuable option?

An autogenous brachial-basilic arteriovenous fistula (BBAVF) in the upper arm must be considered before placing prosthetic grafts in hemodialysis patients with multiple failures of forearm AVFs. The aim of this observational study was to compare technical and clinical outcomes of a new construction technique for BBAVF (n-BBAVF) with that of the standard one-stage side-artery to end-vein transposed BBAVF (t-BBAVF). A n-BBAVF is constructed in the following way: basilic vein and brachial artery are isolated. Patency of the proximal and distal vein is verified by injecting warmed (37 degrees C) saline solution. A venotomy and an arterotomy of 4-5 mm are performed. The two vessels are prepared for a side-to-side anastomosis without transposition of the vein. The latter allows both an antegrade and retrograde flow along the basilic vein, both proximally and distally to the anastomosis with more sites available for the venipunctures of the dialysis. Thirty BBAVFs were constructed as the secondary or tertiary vascular access in 30 patients over a 4-year period: 17 patients with adequate forearm basilic vein underwent the construction of a n-BBAVF; 13 underwent the construction of a t-BBAVF. The construction of a n-BBAVF requires a significantly lesser surgical time (55.0 +/- 9.0 minutes vs. 115.0 +/- 18.0, p < 0.0001), has fewer surgical complications (5.9% vs. 46.2%, p < 0.0001), and a reduced time to first use (24.5 +/- 6.3 vs. 37.7 +/- 9.1 days, p < 0.0001) than that of a t-BBAVF. n-BBAVFs showed a relatively low rate of thrombosis per patient-year at risk (0.067 at 1 year and 0.099 at 2 years). The latter was significantly lower at 1 year when compared with t-BBAVFs (0.067 vs. 0.285; p < 0.004). Our policy of "all AVFs should be autogenous" led us to the construction of a vascular access which is based on a side-to-side anastomosis between the brachial artery and the basilic vein without transposition of the vein allowing both antegrade and retrograde flow into the basilic vein. The results of this surgical technique appear satisfactory.

The relationship between the flow of arteriovenous fistula and cardiac output in haemodialysis patients.

BACKGROUND: Satisfactory haemodialysis (HD) vascular access flow (Qa) is necessary for dialysis adequacy. High Qa is postulated to increase cardiac output (CO) and cause high-output cardiac failure. Aim of the present prospective study was to evaluate the relationship between Qa of arteriovenous fistulas (AVFs) and CO in order to have a closer insight into this scarcely explored aspect of HD pathophysiology. METHODS: Ninety-six patients bearing an AVF entered the study. All were evaluated a priori for the existence of cardiac failure according to the functional classification of the American College of Cardiology/American Heart Association task force. Qa and CO were measured by means of the ultrasound dilution Transonic Hemodialysis Monitor HD02. RESULTS: The mean Qa of the 65 lower arm AVFs was 0.948+/-0.428 SD l/min, whereas that of the 31 upper arm AVFs was 1.58+/-0.553 l/min. The difference was statistically significant (P<0.001). Ten patients were classified as having high-output cardiac failure; seven of them bore an upper arm AVF. Thus, upper arm AVFs were associated with an increased risk of high-output cardiac failure (P<0.04, chi(2) test). A third-order polynomial regression model best fitted the relationship between Qa and CO. The analysis of the regression equation identified 0.95 and 2.2 l/min as Qa cut-off points. The receiver operating characteristic curve analysis showed that Qa values >or= 2.0 l/min predicted the occurrence of high-output cardiac failure more accurately than two other Qa values (sensitivity 89%, specificity 100%, curve area 0.99) and three Qa/CO ratio values (cardio-pulmonary recirculation-CPR). The better performance among the latter was that of CPR values >or= 20% (sensitivity 100%, specificity 74.7%, curve area 0.92). CONCLUSIONS: Our prospective study shows that the relationship between Qa of AVFs and CO is complex and a third-order polynomial regression model best fits this relationship. Furthermore, it is the first study to clearly show the high predictive power for high-output cardiac failure occurrence of Qa cut-off values >or= 2.0 l/min.

Cinacalcet is effective in relapses of secondary hyperparathyroidism after parathyroidectomy.

BACKGROUND: Relapses of secondary hyperparathyroidism (SHPTH) after parathyroidectomy (PTx) in haemodialysis patients are relatively frequent. Calcimimetics (cinacalcet HCl) offer a new therapeutic opportunity for their treatment. However, no data about the treatment with cinacalcet of relapses of SHPTH after PTx are available in literature. The aim of this single-centre prospective study was to evaluate the therapeutic efficacy of cinacalcet in this high-risk category of patients. METHODS: Twelve haemodialysis patients of our Dialysis Unit had a relapse of SHPTH after PTx, defined as serum levels of immunoreactive intact parathyroid hormone (iPTH)>300 pg/ml. They were stratified into a treatment group (the six patients having the highest serum levels of iPTH) and a control group (the remaining six patients): the former were treated for 6 months with a dose of cinacalcet ranging from 30 mg every other day to 60 mg a day; the latter continued to be administered the conventional treatment. Serum levels of albumin, iPTH, calcium (Ca), phosphate (P) and alkaline phosphatase were determined monthly. The treatment group included four cases of nodular hyperplasia and two cases of carcinoma of parathyroid glands, whereas the control group included four cases of nodular hyperplasia and two cases of diffuse hyperplasia. RESULTS: At the start of the study, the six patients treated with cinacalcet showed a more severe picture of biochemical abnormalities when compared with the control patients. After 6 months of treatment, a statistically significant reduction in the serum levels of iPTH, Ca, P and CaxP product was obtained only in the patients treated with cinacalcet. Symptomatic episodes of hypocalcaemia (serum Ca<7.0 mg/dl) were observed in three patients of this group. The six patients undergoing the conventional treatment showed at 6 months a not significant decrease in the mean serum levels of iPTH and a not significant increase in the mean serum levels of Ca, P and CaxP product, when compared with the baseline values. CONCLUSIONS: Our single-centre prospective study, even though small and of short duration, shows that cinacalcet is effective also in controlling relapses of SHPTH after PTx, thus representing a solid, and sometimes unique, therapeutic opportunity for this high-risk category of patients.

Is there a place for duplex screening of the brachial artery in the maturation of arteriovenous fistulas?

Clinically there are some autogenous arteriovenous fistulas (AVFs) that are obviously mature. The real problem in clinical evaluation is in predicting the ultimate outcome of AVFs that are not clearly mature. Thus it would be advantageous to develop objective quantitative criteria to be applied early after vascular access placement in order to evaluate the suitability of AVFs for dialysis. The goal of this study was to document the blood flow rate modifications that the construction and maturation of a radiocephalic wrist AVF produce in the brachial artery by means of duplex Doppler ultrasonography. All incident uremic patients who needed the construction of a radiocephalic wrist AVF in the last 9 months of 2003 were enrolled in the study: 18 patients underwent such an operation. A linear color Doppler ultrasound scan was performed with a 7.0 MHz imaging/5.0 MHz Doppler probe by sampling the brachial artery 2 cm above the elbow: the internal diameter of the artery was measured and its blood flow rate calculated just before AVF construction and 1, 7, 28 days, and at least 6 months after AVF construction. The internal diameter and blood flow rate of the brachial artery were, respectively, 4.3 +/- 0.7 mm and 56.1 +/- 19.2 ml/min at baseline. A new AVF was constructed in one patient whose brachial artery blood flow rate was 80.0 ml/min at 28 days. When excluding this AVF, the mean brachial artery blood flow rate of the 17 AVFs was 720.4 +/- 132.8 ml/min (median 750 ml/min, range 480-890 ml/min) at 28 days and 997.6 +/- 259.7 ml/min 258.0 +/- 63.0 days after AVF construction. When analyzing the percent increase in brachial artery blood flow rate of the 17 AVFs at the different time points, the most dramatic one occurred at day 1 compared to the baseline (549.0%; mean blood flow rate at day 1, 365.0 +/- 129.3 ml/min). Thus the blood flow rate at day 1 represents more than half (50.7%) of the blood flow rate that will be measured at day 28. Then the increase was less steep, with a 20.1% increase between day 7 and day 1 (mean blood flow rate at day 7, 438.4 +/- 86.0 ml/min), a 64.3% increase between day 28 and day 7, and a 38.5% increase at 258.0 +/- 63.0 days compared to 28 days. The present study was able to document the changes in brachial blood flow rate consequent to a radiocephalic wrist AVF maturation by means of duplex Doppler ultrasonography of the brachial artery. This measure may be helpful in monitoring which AVFs will probably fail. This screening should integrate clinical assessment, thus allowing sound judgment of the level of maturation of an AVF and of its outcome.

Are low plasma levels of 25-(OH)vitamin D a major risk factor for hyperparathyroidism independent of calcitriol in renal transplant patients?

BACKGROUND: Recently, some studies have emphasized the role of plasma 25-(OH)vitamin D (25OHD) levels in mineral metabolism dysregulation in chronic kidney diseases (CKDs). However, to date little attention has been paid to 25OHD metabolism abnormalities after renal transplantation (Tx). This cross-sectional study aimed to focus on its role in mineral metabolism dysregulation in functioning Tx. METHODS: Twenty-eight out of 75 Caucasian Tx patients were selected following strict inclusion and exclusion criteria. Two blood samples were effected at the end of the winter for the measurements of plasma 25OHD and calcitriol levels. Serum creatinine (Cr), alkaline phosphatase (SAP), immunoreactive intact parathyroid hormone (PTH), electrolytes and 24-hr proteinuria were also determined. The Kolmogorov-Smirnov test was used to evaluate the data distribution: serum Cr, Cr clearance, dialysis duration and PTH levels were non-normally distributed and were log-transformed. Values of p<=0.01 were assumed as statistically significant. RESULTS: Median serum Cr and PTH levels were, respectively, 1.0 mg/dL and 90.0 pg/mL (range 27-420; normal range 10-65); most of our Tx patients (78.5%) had serum PTH levels above the upper limit of normal values. Mean plasma 25OHD concentration was 19.6 +/- 8.9 SD ng/mL (range: 6-36). None had levels <5 ng/mL (severe deficiency); 10 patients (35.7%) had mild deficiency (5-15 ng/mL); 14 patients (50%) had vitamin D insufficiency (16-30 ng/mL); and only four patients (14.3%) had target levels (>30 ng/mL). Mean plasma calcitriol levels were 69.7 +/- 19.0 pg/mL (range 47-105; normal range 35-85). They were not significantly correlated to plasma 25OHD levels. Proteinuria (292.6 +/- 147.0 mg/24 hr) inversely correlated to plasma 25OHD levels (r=-0.480; p<0.01). The bivariate correlation analysis between logPTH and the other parameters showed a significant correlation for SAP (r=0.494; p=0.008), plasma 25OHD levels (r=-0.442; p=0.01), proteinuria (r=0.452; p=0.01), log serum Cr (r=0.551; p=0.002) and log Cr clearance (r=-0.534; p=0.003). The other parameters did not correlate significantly with logPTH, notably plasma calcitriol and serum phosphate levels. Only the parameters significantly correlated to logPTH in the bivariate correlation analysis were included in the back stepwise multiple linear regression analysis as independent variables (model: p<0.0001; R2=0.54): among them, only plasma 25OHD levels (Beta=-0.486; p=0.001) and log serum Cr levels (Beta=0.589; p=0.0002) were the dependent variable logPTH predictors. CONCLUSIONS: This cross-sectional study demonstrated that plasma calcitriol levels in a highly selected group of Tx patients were normal and not significantly correlated to either plasma 25OHD or serum PTH levels. Most patients (85.7%) had plasma 25OHD levels below the target value of 30 ng/mL; the latter were inversely correlated with serum PTH levels. Therefore, our study strengthens the suggestion that low plasma 25OHD levels are a major risk factor for secondary hyperparathyroidism (sHPTH) in Tx patients and stresses the importance of monitoring these patients.

End-stage renal disease in leprosy.

BACKGROUND: Leprosy or Hansen's disease (HAD) undoubtedly remains an emergency in certain countries. It is an ancient deforming disease caused by Mycobacterium leprae. The countries with the highest endemic leprosy rate in 2000 were Brazil, India and Madagascar. In Italy, the old epidemic has been defeated and there are approximately 400 patients under constant monitoring with three to four new cases per year involving Italian residents. The kidney is one of the target organs during the splanchnic localization of leprosy. The histopathological renal lesion spectrum includes glomerulonephritis (GN), renal amyloidosis (RA) and interstitial nephritis (IN). Both proteinuria and chronic renal failure are the main clinical expressions of renal damage in leprosy. To the best of our knowledge, very little is reported concerning end-stage renal disease (ESRD) in leprosy patients both in the most important national and international renal registries and in the available literature. This study aimed to report the long-term experience of our department in this field. METHODS: To achieve this, we analyzed retrospectively the HAD Center (Gioia del Colle) database at ourhospital. RESULTS: Eight leprosy patients were dialyzed from 1980 to June 2003 (six males and two females), with a mean age of 61.0+/-8.9 SD yrs (range: 51-76) and a mean HAD duration of 36.1+/-5.1 yrs. The first clinical nephropathymanifestations were non-nephrotic proteinuria associated with chronic renal failure in four patients, and nephrotic proteinuria in four patients. Kidney biopsies performed in three patients showed two had RA, and one had IN. Two patients were treated initially by peritoneal dialysis; they were then switched to hemodialysis (HD) after 3 and 10 months because of recurrent peritonitis. HD treatment lasted 40.6+/-31.4 months (range: 9-101). Six patients died, one due to hyperkalemia, one because of a technical dialysis accident, and the remainder due to causes unrelated to the dialysis treatment. Two patients are still alive, treated with HD for 17 and 44 months. CONCLUSIONS: Uremia represents a late complication of leprosy and has a multifactorial genesis, although RA is among the most frequent causes, conventional bicarbonate HD appears to offer good results in the treatment of uremia in leprosy patients.