Correction of congenital hydronephrosis in utero IV: in utero decompression prevents renal dysplasia

Renal dysplasia (RD) is commonly seen in babies with urinary tract obstruction (UTO). Recent experimental evidence suggests that early fetal UTO leads to the development of RD. The RD seen in children with congenital UTO is usually not reversible, even when the obstruction is relieved soon after birth. Is the RD associated with congenital UTO preventable or reversible by decompression of the urinary tract early in gestation? If so, at what stage of development must this decompression be performed? We produced complete unilateral ureteral obstruction in 25 early second trimester (62 to 65 days) lamb fetuses, a procedure that results in ipsilateral RD at term (140 days). At a second operation, 20, 40, or 60 days after the initial procedure, we decompressed the obstructed kidney by a cutaneous end-ureterostomy. The contralateral unobstructed kidneys served as controls. Renal function (urine output and iothalamate clearance) and histopathology were evaluated after delivery at term. Recovery of renal function was directly proportional to the duration of in utero decompression and inversely proportional to duration of obstruction. In addition, in utero decompression prevented or greatly ameliorated the development of RD. However, some postobstructive changes persisted; these were proportional to the length of in utero obstruction. These results substantiate the clinical impression that some human fetuses with congenital UTO may benefit from early in utero decompression.     

Successful Endovascular Treatment for Very-Late-Onset and Acute Progressive Multiple Transplant Renal Segmental Artery Stenoses: A Case Report

PurposeTo report the endovascular treatment for acute progressive and very-late-onset multiple segmental small-artery stenoses in transplanted kidney parenchyma presenting with rapidly deteriorating renal function and refractory hypertension in a 65-year-old man.Case reportNineteen years ago, the patient received a living renal transplant via end-to-end anastomosis of the right internal iliac artery for kidney failure caused by chronic glomerulonephritis. His transplant renal function (creatinine: 0.9 mg/dL) and blood pressure were stable for 18 years. Then rapid worsening of renal function (creatinine: 2.5 mg/dL) and refractory hypertension occurred. Magnetic resonance angiography and renal angiography showed multiple small segmental artery stenoses in the transplanted kidney. At the 1-month follow-up consultation, total occlusion of 2 branches traversing the inferior pole of the kidney was observed, revealing acute progression of artery stenosis. Balloon angioplasty was successfully performed on those branches; renal function improved (creatinine: 1.3 mg/dL), and blood pressure was sufficiently controlled.ConclusionsThis is a rare case that revealed very-late-onset multiple segmental renal artery stenoses with acute progression in the transplant kidney. Even multiple small segmental artery stenoses can reduce transplant renal function in the chronic phase and progress rapidly. Early percutaneous transluminal angioplasty may thus be feasible and important for preventing graft loss.     

肾移植2 123例临床总结

目的：总结肾移植的临床经验,探讨影响肾移植存活的因素,提高长期存活率。方法：回顾性总结2123例肾移植病例的临床资料,对人和（或）肾存活率,供肾的切取,灌注,热冷缺血时间对移植的影响,植肾技术,免疫抑制剂的应用,HLA配型,群体反应抗体（PRA）检测及术后并发症的发生情况等进行了分析。结果：1978－1990年423例中发生超急性排斥反应者9例（2．1％）,急性排斥反应198例（46．8％）,1,3和5年人和（或）肾存活率为86.7%/76.3%,72.5%/67.9%和69.5%/59.3%,1991-2001年,共1700例肾移植,其中未发生超急性排斥反应,急性排斥反应252例（14.8%),1,3和5年人（或）肾存活率高达98.6%/96.7%,93.1%/87.3%和88.1%／83.6%。结论：适应证的选择,高质量的供肾是保证肾移植成功的关键;PRA的检测,良好的HLA配型有利于减少移植肾的早期失功能并提高肾移植长期存活率;加强对肾移植患者的随访,指导康复治疗,对患者能否长期存活有重要意义。     

Reflex anuria from unilateral ureteral obstruction

Renal function is usually normal or only marginally affected in patients with unilateral ureteral obstruction due to the vicarious function of the contralateral kidney. Few reports exist in which unilateral renal obstruction is associated with anuria (reflex anuria, RA) and acute renal failure. We report the clinical case of a female patient who was referred to the emergency department due to anuria of 72 h duration and acute renal failure (serum creatinine 9 mg/dl) associated with several episodes of violent right flank pain with hematuria following extracorporeal shock wave lithotripsy (ESWL). A few weeks before ESWL, urography showed a 2-cm stone located in the right pelvis whilst the left kidney was functionally normal. On admission, renal ultrasound documented a normal left kidney, whilst the right pelvis was hydronephrotic and there were two indwelling stones at the right pyeloureteral junction. After the patient passed a urinary stone, diuresis restarted and acute renal failure was resolved. Thereafter, urography confirmed that the left kidney, the left ureter and bladder were functionally and morphologically normal. RA with acute renal failure has been so scarcely documented that it is considered to be legend by many clinicians. Major textbooks do not discuss RA with acute renal failure. Vascular or ureteral spasm related in part to a peculiar hyperexcitability of the autonomic nervous system may explain RA. We suggest that nephrologists should always consider RA when evaluating acute renal failure. On the other hand, RA might be relatively common and we cannot rule out that only the most severe and/or better-documented cases have been reported in the medical literature.     

Acute Renal Infarction: An Unusual Cause of Abdominal Pain

Acute renal infarction is an uncommon and under-diagnosed disease. Its clinical presentation is nonspecific and often mimics other more common disease entities. The diagnosis is usually missed or delayed, which frequently results in irreversible renal parenchyma damage. High index of suspicion is required for early diagnosis, as timely intervention may prevent loss of kidney function. We report a case of acute renal infarction following coronary angiography in a patient with paroxysmal atrial fibrillation who initially presented with acute abdominal pain mimicking appendicitis.     

Acute renal infarction due to fungal vascular invasion in disseminated candidiasis

Disseminated candidiasis occurs almost exclusively in leukemic patients recovering from neutropenia. Although renal involvement can be a sequela of disseminated candidiasis, acute renal infarction secondary to Candida invading the renal vasculature has not previously been reported. Our patient, who was being treated for acute myelogenous leukemia, developed complete obstruction of the right renal vessels during the course of 36 hours as documented by serial renal ultrasound scans with Doppler investigation of the vasculature. Histopathologic examination of the nephrectomy specimen revealed complete infarction of the kidney secondary to Candida spp. infiltrating the parenchyma and occluding the hilar vessels.     

Elevated tubular proteinuria, albuminuria and decreased urinary N-acetyl-β-D-glucosaminidase activity following unilateral total ureteral obstruction in rats

Urinary tubular proteinuria and N-acetyl-β-d-glucosaminidase (NAG) activity has not yet been studied after unilateral total ureteral obstruction (UTO). The aim of the study was (1) to evaluate in a longitudinal study (7 weeks) the behaviour and the potential clinical value of tubular proteinuria and urinary NAG activity after UTO; (2) to study the physiopathology of the non-obstructed contralateral kidney by using these two different markers of tubular damage. Methods: in 28 female, adult Wistar rats (UTO: n= 16, sham: n= 12), tubular proteinuria and urinary NAG activity were measured before and 1 and 5 weeks after surgery. Results: a significant (P < 0.01) increase in tubular proteinuria/creatinine ratio and urinary creatinine and a decrease in urinary NAG activity was found 1 week after UTO. All parameters normalized after 6 weeks. Albuminuria increased progressively (P < 0.01) during the study. Conclusion: tubular proteinuria increases during the first week following UTO in rats. The initial increase of low molecular weight proteins following UTO is not due to tubular damage as no parallel increase of urinary NAG was found. We suggest an initial tubular overperfusion with primary urine, due to an increased single nephron glomerular filtration and overruling the reabsorption capacity of the proximal tubules. Received: 1 December 1997 / Accepted: 2 March 1998     

Sequential renography in acute urinary tract obstruction due to stone disease

A group of 76 patients with urographically proven acute calculus obstruction was studied prospectively using 99mTc-DTPA renography to see if kidneys at risk of irreversible renal damage could be identified. There was a statistically significant relationship between the presence of obstruction on renography and the subsequent requirement for intervention, but not with the degree of obstruction (partial or severe). Stones over 5 mm in size are highly likely to cause obstruction, a drop in relative renal function and require intervention. In all, 14 patients sustained a drop in relative renal function of greater than 7% on renography and 12 of these returned to normal limits when their calculi had been passed or removed. The 2 kidneys whose function remained impaired had fallen below 25% of overall renal function and both patients had received prior treatment for their calculi. No patient who presented de novo suffered any permanent loss of ipsilateral renal function. The results confirm that the criteria for intervention were well founded and emphasise the importance of achieving a stone-free state after primary treatment. Renography is recommended for stones over 5 mm in size, those in the middle and upper ureter and for those patients discharged with a stone in situ.     

Acquired glomerulocystic kidney disease following hemolytic uremic syndrome

Glomerulocystic kidney disease (GCKD) is a rare congenital condition that is usually reported in infants and young children. Only five cases of acquired GCKD after an acquired renal disease have been reported. Among these, two patients have developed cystic glomerular lesions following hemolytic uremic syndrome (HUS). We report a third case in a 2-year-old patient with this association. Common features between these three cases include atypical HUS, development of GCKD after prolonged peritoneal dialysis treatment, severe hypertension, and normal-sized kidneys without development of macroscopic cysts. Pathology findings in our patient include heavy expression of epidermal growth factor receptor in proximal tubules and evidence of obstruction of the glomerular outflow. We speculate that cystic dilatation of the Bowman’s capsule may be secondary to ischemic lesions leading to proximal tubular obstruction. Received: 6 October 2000 / Revised: 1 February 2001 / Accepted: 13 February 2001     

Evolution of single kidney glomerular filtration rate in urinary tract infection

 The aim of this study was to evaluate renal function during the acute phase of symptomatic urinary tract infection and the changes observed several months later. Overall glomerular filtration rate (GFR) as well as single kidney GFR (SKGFR) were calculated using the combination of a left/right uptake ratio obtained from technetium 99m-dimercaptosuccinic acid (DMSA) scintigraphy and ⁵¹chromium-EDTA plasma clearance. Forty-four patients with obvious unilateral or bilateral DMSA abnormalities were studied. In patients with unilateral lesions, both the overall GFR and the SKGFR were significantly higher during the acute phase of infection than several months later, on the abnormal side as well as the normal side. The relative percentage uptake was lower on the abnormal side than the normal side, obviously due to loss of functional parenchyma. This percentage increased significantly during the recovery phase, reflecting the total or partial healing of the renal lesions, despite the decrease of the corresponding SKGFR. However, during both the acute and the recovery phase, the relative percentage uptake of the abnormal kidney was in the normal range and often close to 50%. In patients with bilateral lesions, no significant changes were observed between the acute phase and the recovery phase. Received: 9 February 1998 / Revised: 16 June 1998 / Accepted: 17 June 1998     

Renal cortical nephrocalcinosis following acute renal failure due to polytrauma

Renal cortical nephrocalcinosis is a rare condition in which there is calcification within the renal parenchyma. This article reports a 33-year-old patient who developed acute renal failure following multiple injuries leading to hemorrhagic shock. His renal failure improved gradually, though he required dialysis support for two months. Serial ultrasounds showed a progressive decrease in renal size, and a radiograph of the abdomen showed speckled calcification in both renal areas. A CT scan of abdomen showed diffuse cortical calcification involving the entire right kidney and upper half of the left kidney.     

Kidney transplantation in a girl with methylmalonic acidemia and end stage renal failure

Methylmalonic acidemia (MMA) is an inborn error of organic acid metabolism that occurs in infancy with hypotonia, vomiting, dehydration, lethargy and failure to thrive and is biochemically characterized by metabolic ketoacidosis, hyperammonemia and sometimes hyperglycinemia. It results from deficiency of methylmalonyl-CoA mutase activity due to a defect in the mutase apoenzyme or to deficient function of one of the enzymes required for metabolism of its cofactor vitamin B₁₂. Tubulointerstitial nephritis with progressive impairment of renal function is one of the most frequent long-term complications. We describe a case of a 17-year-old girl with methylmalonic acidemia unresponsive to vitamin B₁₂ therapy. The clinical symptoms appeared at 4 months of life. She progressed into end stage renal disease and in January 1996 she started on hemodialytic treatment. In November 1996 we performed a kidney transplant. At present, urinary excretion of methylmalonic acid is normal and the renal function of the transplanted kidney is normal without any rejection episodes. We think that a kidney transplant could be a good therapeutic choice for the metabolic alterations in MMA with end stage renal disease. Indeed it would seem that the small methylmalonyl-CoA mutase activity present in the transplanted kidney could be sufficient to ensure normal metabolism of organic acids. Otherwise, the therapeutic goal can be achieved with a protein-restricted diet. Received: 7 February 2001 / Revised: 27 June 2001 / Accepted: 28 June 2001     

Renal Cortical Nephrocalcinosis Following Acute Renal Failure Due to Polytrauma

Renal cortical nephrocalcinosis is a rare condition in which there is calcification within the renal parenchyma. This article reports a 33-year-old patient who developed acute renal failure following multiple injuries leading to hemorrhagic shock. His renal failure improved gradually, though he required dialysis support for two months. Serial ultrasounds showed a progressive decrease in renal size, and a radiograph of the abdomen showed speckled calcification in both renal areas. A CT scan of abdomen showed diffuse cortical calcification involving the entire right kidney and upper half of the left kidney.     

Upward migration of indwelling ureteral stents.

Polyethylene ureteral stents suspended from the kidney by a pigtail memory in the proximal end were placed bilaterally in a patient with ureteral obstruction secondary to retroperitoneal sarcoma. Both stents migrated upward and 1 migrated into the renal parenchyma. We recommend that these stents be inserted into the renal pelvis, as opposed to the calices, and that sufficient length be allowed to prohibit migration above the bladder.     

Recurrent membranoproliferative glomerulonephritis after second renal graft treated with plasmapheresis and rituximab

We present a case of a 45-year-old man who suffered from idiopatic membranoproliferative glomerulonephritis (MPGN) in the native kidney that relapsed after his first and second renal grafts. The patient was diagnosed in 1990 with lobular MPGN type I, receiving his first renal graft in 1996. In 2001, a biopsy showed recurrence of MPGN type I (rMPGN). He underwent a second renal graft in 2008. In January 2010, he experienced increased proteinuria and creatinine. Upon electron microscopy of a renal graft biopsy we diagnosed a new rMPGN. At the time of the biopsy, complement levels were normal, although C3 and C4 decreased further. We administered 12 plasmapheresis (PP) sessions and four doses of rituximab. Due to persistent renal impairment, we performed a new biopsy 3 months later, showing less severity of the acute lessions. He received a new cycle of treatment (PP + rituximab). One year later, his renal function was stable with a creatinine ranging between 2 and 2.5 mg/dL and a protein/creatinine ratio less than 1 mg/mg. We concluded that the treatment stopped the disease progression.     

Xanthogranulomatous pyelonephritis: our experience with review of published reports

BACKGROUND: The aim of this study was to analyse the cases of xanthogranulomatous pyelonephritis with review of published reports. METHODS: We retrospectively reviewed all nephrectomy specimens during February 1995 to January 2006. We found 26 cases of xanthogranulomatous pyelonephritis. We prepared a chart of these cases consisting of preoperative symptoms, laboratory findings, radiological imaging results and preoperative diagnosis. Open nephrectomy was carried out in all cases. RESULTS: Age group of the patients was 6-65 years and male : female ratio was 1.6:1. Twenty-two patients presented to us with intermittent high-grade fever, 21 with flank pain, 18 with loin mass, 2 with haematuria and 1 was detected during screening of vague gastrointestinal symptoms. Twenty-five patients had pyuria and only 10 had sterile urine culture. In all patients, only one kidney was affected. All patients had renal calculi 10-42 mm in size with bilaterally enlarged kidneys. Ipsilateral kidney was enlarged because of hydronephrosis or pyonephrosis in all cases and contralateral kidney was enlarged because of compensatory hypertrophy in 13 cases. Ipsilateral kidney had severely compromised renal function in all cases. Associated psoas abscess was present in one and tuberculosis in another. CONCLUSION: Xanthogranulomatous pyelonephritis is a relatively rare entity that is associated with obstruction, stones and infection of the urinary tract. Late presentation leads to loss of renal parenchyma. It cannot be differentiated preoperatively with renal tumours (renal cell carcinoma and Wilms' tumour), pyonephrosis, infected hydronephrosis and renal lymphoma. Nephrectomy and antibiotics are the treatment of choice.     

Image guided localized 31P magnetic resonance spectroscopy of acute urinary tract obstruction

Using 31P magnetic resonance spectroscopy, localized spectroscopy and magnetic resonance imaging we studied effects of acute urinary obstruction in the in vivo pig kidney. Accumulation of urine in the renal pelvis and collecting ducts resulted in the appearance of a new peak in the localized phosphorus spectra originating in the renal papilla, resonating at 3.43 to 4.56 ppm. This was inorganic phosphate with a pH of 5.60 to 6.79 (urine pH). Imaging did not show any dilatation of renal pelvis. There was a significant time dependent fall in renal [ATP] during urinary obstruction followed by a rapid "overshoot" of [ATP] and disappearance of the phosphate peak after release of obstruction. Possible mechanisms for this phenomenon are discussed. We conclude that 31P magnetic resonance spectroscopy provides early evidence of urinary obstruction in vivo and could be of value in clinical diagnosis.     

Natural history of fetal and neonatal hydronephrosis

Since pyelocalicectasis alone is common in fetuses, we reviewed reports of fetal hydronephrosis that resolved spontaneously or at birth. Severe fetal hydronephrosis with calicectasis or parenchymal thinning rarely resolves spontaneously before or after birth. We also reviewed the clinical and experimental literature on renal hypertrophy. After unilateral nephrectomy in neonatal animals or after birth with congenital absence of one kidney in humans, the remaining kidney hypertrophies very quickly. In infants and young animals, the eventual size of the remaining kidney is inversely proportional to the age at which one kidney is lost. This improvement in residual renal function seen after renal loss in infancy, compared with older children, itself constitutes a strong argument for early relief of obstruction. If contralateral renal hypertrophy has occurred, the treated damaged kidney may resume growth in parallel with its hypertrophied mate but does not become as large or recover normal potential for growth. In other words, if correction of a unilateral obstruction is deferred until contralateral hypertrophy occurs, the obstructed kidney then has less potential for recovery of function.     

Continent urinary diversion in preparation for renal transplantation: a staged approach

BACKGROUND: We prospectively assessed the safety of kidney transplantation into continent urinary intestinal reservoirs as a planned two-stage procedure in patients with absent or dysfunctional lower urinary tract. METHODS: Between November 1990 and June 1999, 12 patients have undergone renal transplantation into continent urinary reservoirs, and a further patient with a diversion is awaiting transplantation. This was part of a larger series of 356 patients who had undergone continent diversions during that period. A further 174 patients (33%) had diversions into ileal conduits. FINDINGS: Within a mean follow-up of 26.1 months (5-72) after transplantation renal function was stable with serum creatinine values ranging from 0.9 to 1.8 mg/dl. There were 5 reoperations in the 12 patients (40%). Two patients needed their continence mechanism replaced. One had renal vein thrombosis with loss of the transplant. The cause for this was unknown but it had been speculated that it could have been caused by graft/body size disproportion. A second kidney was successfully transplanted after 12 months. Two further revisions were required for ureteric kinking and lymphocele. The patient with orthotopic substitution voids to completion. The other patients are continent day and night with easy catheterization. INTERPRETATION: This is one of the largest single series reported to date of renal transplantation into continent urinary diversions, and we commend the approach in carefully selected patients, but the difficulties must not be underestimated and the specific problems of intestinal urinary reservoirs have to be reckoned with. These procedures should be confined to centers with considerable experience with this type of surgery and its complications. Lifelong close surveillance is critical for the success of this concept.     

Long-term renal allograft function on a tacrolimus-based, pred-free maintenance immunosuppression comparing sirolimus vs. MMF.

It is not known how different steroid-free immunosuppressive combinations affect renal graft survival and long-term kidney transplant function. Here we sought to compare the impact on graft survival and long-term graft function of two tacrolimus (Tac)-based, prednisone-free maintenance immunosuppressive protocols: Tac/Mycophenolate Mofetil (MMF) vs. Tac/Sirolimus (SRL). Renal transplant patients given induction therapy with IL2-RA and methylprednisolone on days 0, 1 and 2 post-transplant were prospectively randomized to two maintenance immunosuppressive regimens with Tac/MMF (n = 45) or Tac/SRL (n = 37). During the 3-year follow-up the following data were collected: patient survival, renal allograft survival, incidence of acute rejection and glomerular filtration rate (GFR) at different time-points post-transplant. Cumulative graft survival was significantly different in the two groups: one kidney loss in the Tac/MMF vs. six kidney losses in the Tac/SRL (log-rank test p = 0.04). GFR at different time-points post-transplant was consistently and statistically better in the Tac/MMF than in the Tac/SRL group. The slope of GFR decline per month was flatter in the Tac/MMF than in the Tac/SRL group. This study showed that renal graft survival and graft function were significantly lower in the combination of Tac/SRL than Tac/MMF.