Post-operative Aspirin in preventing early renal allograft thrombosis: A meta-analysis

@#BACKGROUND: Kidney transplantation (KT) remains to be the preferred mode of renal replacement therapy as it offers the best clinical outcomes, a better quality of life, and lesser complications compared to dialysis. However, KT still carries a number of complications, one of which is graft thrombosis. Despite advancements in treatment, graft thrombosis is still an important cause of early graft loss. Prevention therefore, is of significance. A growing number of evidence suggests that low-dose aspirin has a role in the primary prevention of allograft thrombosis. RESEARCH QUESTION: Among renal transplant recipients, does postoperative aspirin prevent early renal allograft thrombosis? OBJECTIVE: To conduct a meta-analysis to determine the effect of postoperative aspirin on preventing renal allograft thrombosis. METHODS: A systematic search of PubMed, Google Scholar, CENTRAL, and clinicaltrials.gov was done by two independent authors. All randomized and non-randomized studies determining the effect of postoperative aspirin on renal vein/allograft thrombosis were reviewed for eligibility and quality assessment. Studies on both adult and pediatric kidney transplant recipients were included. RESULTS: Five non-randomized cohort studies (3 in adults, 2 in children) with a total of 2,393 patients were included. Using the Newcastle-Ottawa scale, two studies were found to have good quality, while three had poor quality. In a fixed-effects meta-analysis, aspirin was associated with a reduced risk for renal allograft thrombosis in adults (RR 0.13; 95% CI 0.06, 0.28;I2 22%) and children (RR 0.11; 95% CI 0.03, 0.40; I2 0%). CONCLUSION: Post-operative aspirin was associated with reduced risk for renal allograft thrombosis in both adults and children. However, the best available evidence is limited to observational studies. A well-designed randomized controlled trial is needed to confirm this finding.

Rare Case of Bilateral Renal Vein Thrombosis: A Case Report

Bilateral renal vein thrombosis (RVT) is a rare clinical condition. Acase of a patient initially presenting with fever with a diagnosisof Plasmodium falciparum malaria was further investigated and it was found to have bilateral RVT. The patient was successfullytreated with anti-coagulants and immunosuppressant.

Lessons Learned from Inappropriate Ligation of the Left Renal Vein for a Large Splenorenal Shunt in Living Donor Liver Transplantation / 대한이식학회지

During living donor liver transplantation, a large spontaneous splenorenal shunt (SRS) should be addressed to obtain adequate portal inflow. Various procedures such as direct ligation of the SRS, splenectomy, left renal vein ligation (LRVL), and renoportal anastomosis can be applied to treat a large SRS according to the hemodynamics of the portal flow and anatomic conditions. Of these surgical procedures, LRVL is a simple and effective solution for treatment of a large SRS. However, to perform a LRVL, rigorous evaluation of the recipient's anatomic and hemodynamic variations is mandatory. In the present case, we ligated the left renal vein to treat a large SRS, which resulted in an unexpected thrombosis of the left renal vein and remaining portal vein stenosis in the SRS. Therefore, we revised our decisions regarding whether the LRVL was properly applied.

A Case of Renal Vein Thrombosis in a Patient with Ulcerative Colitis / 대한소화기학회지

Venous thrombosis and thromboembolism appear to occur more often in patient with inflammatory bowel disease (IBD). The cause of thrombotic complications in IBD is generally considered to be associated with hypercoagulable conditions. Its prevalence rate ranges from 1% to 8% in clinical studies and rises to 39% in autopsy, but the renal vein thrombosis is very rare complication in ulcerative colitis patient. A 24-year-old man presented with intermittent abdominal pain and hematochezia for 6 months and recently developed pitting edema for few weeks. He was diagnosed as severe ulcerative colitis involving whole colon combined with thrombosis in both renal veins by colonoscopy and computed tomography scan of abdomen. We used steroid for the treatment of ulcerative colitis and both intravenous lower molecular weight heparin and warfarin for renal vein thrombosis. His symptoms were improved after treatment and maintained with mesalazine and warfarin. Follow-up abdominal CT scan showed complete resolution of both renal vein thrombosis. Currently he has been followed up for 2 years with oral mesalazine.

Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

OBJECTIVE: To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. MATERIALS AND METHODS: We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. RESULTS: We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. CONCLUSION: The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion.

Ultrasonographic Findings of Acute Renal Vein Thrombosis in Experimental Rabbit Model: Focus on Renal Doppler Sonography

PURPOSE: To evaluate Doppler sonographic findings of acute renal vein thrombosis in rabbit model induced by renal vein ligation, with an emphasis on the changes in resistive index (RI) on serial follow-up. MATERIALS AND METHODS: Conventional and Doppler sonographies were performed immediately after ligation and 24, 48, and 72 hours after ligation in 12 rabbits weighing 4.5-5.0 kg. We focused on changes in kidney size and echogenicity with conventional sonography and resistive index by time interval and Doppler waveforms with Doppler sonography. RESULTS: Kidney size increased markedly immediately after ligation, and increased slowly until 48 hours after ligation with no change observed afterwards. Echogenicity increased both in the renal cortex and the medulla. RI increased remarkably to an average of 1.38 immediately after ligation, and increased to a peak average of 1.64 48 hours after ligation. After 72 hours RI decreased slightly to 1.59. Reverse 'plateau-like' diastolic waveform was seen in 27 trials (56%) on follow up Doppler sonograms. CONCLUSION: The increase in RI was thought to be due to the increase in renal arterial vascular resistance caused by venous outflow obstruction. The decrease in RI with time suggested adaptation of intrarenal circulation to renal vascular change. Also, the reverse 'plateau-like' diastolic waveform was the predominant waveform.

A Magnetic Resonance Angiographic Diagnosis and Successful Thrombolytic Therapy in The Thrombosis of Renal Vein Complicated from Nephroitc Syndrome / 대한신장학회잡지

The nephrotic syndrome has been considered a hypercoagulable state since it may be complicated by thromboembolic events of the venous or the arterial circulations. Diverse pathogenetic factors leading to the hypercoagulable state in nephrotic syndrome have been recognized. Renal vein thrombosis is a serious complication, which might lead to either renal failure or to secondary thromboembolic processes like pulmonary thromboembolism. Although it may present acutely with flank pain and macroscopic hematuria, the majority of cases run an indolent course. Until relatively recently, the diagnosis could only be confidently confirmed or excluded with selective renal venography but, more recently, computerized tomography and magnetic resonance imaging have been used. Anticoagulant therapy with heparin and warfarin apparently halts the natural progression of the disease and allowing for slow recovery. The possibility of more rapid and complete resolution with thrombolytic agents warranted their application. We described a case of bilateral renal vein thrombosis diagnosed by the new technique of magnetic resonance angiography and successful treatment by thrombolytic agent.

A Case of Renal Vein Thrombosis in a Patient with Lung and Uterine Cervical Cancer / 대한신장학회잡지

Thrombosis of one or both renal veins occurs in a variety of settings such as trauma, dehydration, extrinsic compression, nephrotic syndrome, pregnancy, oral contraceptives or invasion by tumor. Nephrotic syndrome and certain carcinomas seem to predispose to the development of renal vein thrombosis. The most common carcinoma which is associated with renal vein thrombosis is the renal cell carcinoma. But, renal vein thrombosis associated with tumor other than renal cell carcinoma is extremely rare. Our patient was diagnosed as lung and uterine cervical cancer by histologic examination. The patient complained of left flank pain. Abdominal CT scan shows the dilated left renal vein filled with hypodense material and parenchymal infarction on the left kidney. Renal arteriography shows cut-off sign on a branch of the left renal artery. Inferior venacavography revealed contrast-filling defect in the left renal vein. To our knowledge, renal vein thrombosis with lung and uterine cervical carcinoma is the first report in English literature. So, we have presented a rare case of a renal vein thrombosis in a patient with lung and uterine cervical cancer.

Patchy signal within Venous Tumo Thrombusin Patients with Renal Cell Carcinoma: A Helpful MR Sign suggestingTumor Neovascularity

PURPOSE: Tumoral neovascularity characteristic of venous invasion of renal cell carcinoma has been demonstrated using angiography, computed tomography, and color Doppler duplex ultrasonography. Previous reports on the characteristic findings of MR imaging have, however, been sporadic. The purpose of this study was to evaluate the usefulness of a patchy signal seen on MR images within the venous thrombus of renal cell carcinoma as a sign of tumor neovascularity. MATERIALS AND METHODS: Six patients with histopathologically-proven unilateral renal cell carcinoma (right:left=3:3) with venous tumor thrombi were included in this study. MR imaging findings were retrospectively analyzed with respect to the presence of patchy signals within a thrombus in a renal vein, the IVC, or the right atrium. MR imaging findings on spin-echo and gradient-echo images were compared with histopathologic findings especially in terms of tumor neovascularity. RESULTS: On histopathologic examination, a tumor thrombus was found in the renal vein in three patients, in the IVC in six, and within the right atrium in two. Patchy signals were demonstrated on MR images in one of three patients with renal vein invasion, in four of six with IVC invasion, and in both patients with right atrial invasion. CONCLUSION: On MR imaging, a patchy signal within a venous thrombus is a helpful sign suggesting tumor neovascularity, one of the characteristics of venous invasion by renal cell carcinoma.

Recovery of Bilateral Renal Vein Thrombosis after Peritoneal Dialyis in a Newborn Neonate

A 4 day old male neonate with severe dehydration, uremia, and hyperbilirubinemia presented with bilateral renal vein thrombosis. Following exchange transfusion and peritoneal dialysis renal function returned to normal without nephrectomy. The importance of adequate and prompt management of renal failure to expect the spontaneous recanalization is stressed. Because of the high mortality rate associated with the nephrectomy in neonates, adequate and prompt medical management including peritoneal dialysis or exchange transfusion, if indicated, with expectation of spontaneous recovery is considered the treatment of choice in this age group.