Contrast-enhanced ultrasonography in the early period after kidney transplantation predicts long-term allograft function.

INTRODUCTION: Real-time contrast-enhanced sonography (CES) can assess microvascular tissue perfusion using gas-filled microbubbles. The purpose of the study was to evaluate the feasibility of early CES in predicting long-term kidney allograft function in comparison to color Doppler ultrasonography (CDUS). METHODS: We prospectively studied 68 consecutive kidney transplant recipients using CES and conventional CDUS investigation 1 week after transplantation. Transplant tissue perfusion imaging was performed by low-power imaging during intravenous administration of the sonocontrast SonoVue. Renal tissue perfusion was assessed quantitatively using flash replenishment kinetics of microbubbles to estimate renal blood flow (RBF). The obtained sonography values were correlated with clinical data 1 week up to 1 year after transplantation. RESULTS: In contrast with conventional CDUS resistive indices, RBF estimated by CES 1 week posttransplantation significantly correlated with kidney function after 1 year (r = 0.67; P < .001). Determination of RBF by CES revealed a significant correlation with donor age but not recipient age, whereas conventional CDUS resistive index was significantly correlated to recipient age (r = 0.54; P < .001) but not donor age. Furthermore RBF was associated with vascular fibrosis and intimal thickening of the engraftment biopsies. CONCLUSION: This is the first prospective study demonstrating the prognostic value of CES early after kidney transplantation. In contrast with CDUS, CES reveals information about kidney allograft perfusion independent of recipient vascular compliance.

Stent design lowers angiographic but not clinical adverse events in stenting of symptomatic intracranial stenosis - results of a single center study with 100 consecutive patients.

BACKGROUND AND AIMS: Comparing safety and technical success of balloon-expandable stents and self-expanding stents for intracranial angioplasty and stenting in medically refractory intracranial atherosclerotic disease in a single center series. METHODS: Fifty-four self-expanding stents and 46 balloon-expandable stents were implanted in 100 consecutive patients (mean age 64 years, 74% male) from April 2000 to September 2009. All patients had symptomatic intracranial stenosis (anterior circulation, n = 40; posterior circulation, n = 60), presenting with recurrent transient ischemic attack or stroke under antithrombotic treatment. Mean degree of stenosis before treatment was 83 ± 13%. We assessed safety, defined as any stroke or death during the procedure and at 30 days follow-up, and technical success, defined as accurate delivery of the stent at the site of the target lesion. RESULTS: Safety - periprocedural stroke or hemorrhage occurred in 11 patients treated with balloon-expandable stent, and in 14 of the patients treated with a self-expanding stent. One patient with a balloon-expandable stent died because of acute vessel rupture during treatment. One balloon-expandable stent and one self-expanding stent patient developed a severe reperfusion hemorrhage that resulted in death. Overall, the combined stroke and death rate at 30-day follow-up was 25·0% (23·9% for balloon-expandable stent group and 25·9% for the self-expanding stent group, P = 0·84). Technical success - intracranial angioplasty and stenting was technically successful in 96·3% of the self-expanding stent and 89·1% of the balloon-expandable stent patients (P = 0·31). Vascular complications were significantly less frequent in patients treated with a self-expanding stent (11·1%) than with a balloon-expandable stent (36·9%, P = 0·002). CONCLUSION: Despite a high technical success, the rate of clinical adverse events at 30 days after intracranial angioplasty and stenting is high independently of the stent design. Thus, further development of intracranial stent systems and careful patient selection are mandatory.

[Combined liver-kidney and kidney after liver transplantation: indications and experiences from a nephrological perspective at a single center]. / Die kombinierte und sequentielle Leber-Nieren-Transplantation: Indikationen und Zentrumserfahrungen aus Sicht des Nephrologen.

Combined liver-kidney transplantations (CLKT) and kidney after liver transplantations (KALT) are established treatments for patients with end-stage hepatic and renal disease and the number of transplantations has continuously increased over the past few years. The most frequent indications for CLKT in adults are polycystic kidney disease with severe liver involvement and liver cirrhosis of different origins with concomitant chronic kidney failure due to chronic glomerulonephritis or diabetic nephropathy. In children, CLKT is most frequently required due to primary oxalosis type I. At present the main indication for KALT still is calcineurin inhibitor-induced chronic nephrotoxicity, emphasizing the need for a nephron-sparing long-term immunosuppression in liver transplant recipients. Compared to KALT, the indications for CLKT are not as well defined and the decision must therefore be made on a case-by-case basis by a multidisciplinary team of experienced clinicians to avoid unnecessary transplantations of both organs in patients with reversible kidney failure, given the scarcity of organs for transplantation worldwide. In hepatorenal syndrome CLKT should only be considered if the GFR is lower than 20 ml/min for more than three months or if the patient has been on renal replacement treatment for more than one month. In CLKT, there appears to be a certain immunological protection for the kidney transplant by the liver transplant.

A single center experience of combined liver kidney transplantation.

With advancements in the operative techniques, patient survival following liver transplantation (LTx) has increased substantially. This has led to the acceleration of pre-existing kidney disease because of immunosuppressive nephrotoxicity making additional kidney transplantation (KTx) inevitable. On the other hand, in a growing number of patients on the waiting list to receive liver, long waiting time has resulted in adverse effect of decompensated liver on the kidney function. During the last two decades, the transplant community has considered combined liver kidney transplantation (CLKTx) to overcome this problem. The aim of our study is to present an overview of our experience as well as a review of the literature in CLKTx and to discuss the controversy in this regard. All performed CLKTx (n = 22) at our institution as well as all available reported case series focusing on CLKTx are extracted. The references of the manuscripts were cross-checked to implement further articles into the review. The analyzed parameters include demographic data, indication for LTx and KTx, duration on the waiting list, Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, immunosuppressive regimen, post-transplant complications, graft and patient survival, and cause of death. From 1988 to 2009, a total of 22 CLKTx were performed at our institution. The median age of the patients at the time of CLKTx was 44.8 (range: 4.5-58.3 yr). The indications for LTx were liver cirrhosis, hyperoxaluria type 1, polycystic liver disease, primary or secondary sclerosing cholangitis, malignant hepatic epithelioid hemangioendothelioma, cystinosis, and congenital biliary fibrosis. The KTx indications were end-stage renal disease of various causes, hyperoxaluria type 1, polycystic kidney disease, and cystinosis. The mean follow-up duration for CLKTx patients were 4.6 +/- 3.5 yr (range: 0.5-12 yr). Overall, the most important encountered complications were sepsis (n = 8), liver failure leading to retransplantation (n = 4), liver rejection (n = 3), and kidney rejection (n = 1). The overall patient survival rate was 80%. Review of the literature showed that from 1984 to 2008, 3536 CLKTx cases were reported. The main indications for CLKTx were oxalosis of both organs, liver cirrhosis and chronic renal failure, polycystic liver and kidney disease, and liver cirrhosis along with hepatorenal syndrome (HRS). The most common encountered complications following CLKTx were infection, bleeding, biliary complications, retransplantation of the liver, acute hepatic artery thrombosis, and retransplantation of the kidney. From the available data regarding the need for post-operative dialysis (n = 673), a total of 175 recipients (26%) required hemodialysis. During the follow-up period, 154 episodes of liver rejection (4.3%) and 113 episodes of kidney rejection (3.2%) occurred. The cumulative 1, 2, 3, and 5 yr survival of both organs were 78.2%, 74.4%, 62.4%, and 60.9%, respectively. Additionally, the cumulative 1, 2, 3, and 5 yr patient survival were 84.9%, 52.8%, 45.4%, and 42.6%, respectively. The total number of reported deaths was 181 of 2808 cases (6.4%), from them the cause of death in 99 (55%) cases was sepsis. It can be concluded that there is still no definitive evidence of better graft and patient survival in CLKTx recipients when compared with LTx alone because of the complexity of the exact definition of irreversible kidney function in LTx candidates. Additionally, CLKTx is better to be performed earlier than isolated LTx and KTx leading to the avoidance of deterioration of clinical status, high rate of graft loss, and mortality. Shorter graft ischemia time and more effective immunosuppressive regimens can reduce the incidence of graft malfunctioning in CLKTx patients. Providing a model to reliably determine the need for CLKTx seems necessary. Such a model can be shaped based upon new and precise markers of renal function, and modification of MELD system.