Duplex Doppler sonography in renal allografts: the significance of reversed flow in diastole

This study was undertaken to assess the significance of diastolic flow reversal seen on duplex Doppler sonograms of patients with renal transplant dysfunction. Earlier studies have evaluated the causes of increased vascular resistance in renal transplants. None, however, have investigated specifically the subset of patients in whom impedance in the renal microcirculation has increased to the degree that retrograde arterial flow is present. In our series, 533 consecutive scans in 270 patients were reviewed. The patients were referred for evaluation of renal transplant dysfunction during a 25-month period. Doppler samples were obtained from main, segmental, and, when possible, arcuate arteries. An episode of reversed diastolic flow was identified in nine patients. Correlation was made with clinical, laboratory, histologic (biopsy in six patients, nephrectomy in three patients), and imaging studies (DTPA scintigraphy in seven patients, angiography in one patient). On the basis of histologic and nephrectomy results, we determined that among the nine patients, four had acute tubular necrosis, three had acute rejection, and two had renal vein thrombosis. One of these patients had both severe rejection and renal vein thrombosis. One additional patient had neither biopsy nor nephrectomy and was not included in the diagnostic groups listed here. Our study suggests that reversed diastolic flow is not specific for either acute rejection or acute tubular necrosis. Reversal of diastolic flow, however, is a poor prognostic sign; nephrectomy was imminent in three of the nine patients. Furthermore, two (22%) patients had renal vein thrombosis, whereas renal vein thrombosis was not found in any of the 261 patients without reversed diastolic flow. Duplex Doppler examinations with reversed diastolic flow should suggest renal vein thrombosis.     

Atypical low-signal-intensity renal parenchyma: causes and patterns.

Certain renal diseases manifest as low signal intensity of the renal parenchyma on magnetic resonance images. Sometimes, the appearance is sufficiently characteristic to allow a specific radiologic diagnosis to be made. The causes of this finding can be classified into three main categories on the basis of the pathophysiology: hemolysis, infection, and vascular disease. The first category includes paroxysmal nocturnal hemoglobinuria (PNH), hemosiderin deposition in the renal cortex from mechanical hemolysis, and sickle cell disease. The second category includes hemorrhagic fever with renal syndrome (HFRS). The third category includes acute renal vein thrombosis, renal cortical necrosis, renal arterial infarction, rejection of a transplanted kidney, and acute nonmyoglobinuric renal failure with severe loin pain and patchy renal vasoconstriction. These disease processes have different patterns of low signal intensity. PNH, hemosiderin deposition from mechanical hemolysis, and sickle cell disease involve the entire cortex including the columns of Bertin. HFRS involves the medulla, especially the outer medulla, whereas cortical necrosis involves the inner cortex including the columns of Bertin. In renal vein thrombosis, low-signal-intensity lesions involve the outer medulla, an appearance resembling that of HFRS. Wedge-shaped low-signal-intensity regions involving both the cortex and the medulla are seen in arterial infarction.     

Selective low-dose streptokinase infusion in the treatment of acute transplant renal vein thrombosis

A renal transplant recipient developed acute renal transplant vein thrombosis following surgery for a total hip replacement. As an alternative to standard surgical therapy, the patient was treated with selective intravenous low-dose infusion of streptokinase at doses of 5,000–20,000 units/h. The infusion was continued for 120 h with constant monitoring of PT, PTT, and fibrinogen levels. Therapy resulted in excellent preservation of renal function without complications. Low-dose selective infusion of streptokinase should be considered a potential alternative therapy for acute transplant renal vein thrombosis.     

Postpartum renal vein thrombosis

Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two postpartum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.     

Postpartum renal vein thrombosis

Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two post-partum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.     

Iliofemoral vein thrombosis and pulmonary embolism associated with a transient ischemic attack in a patient with antiphospholipid syndrome

Several clinical conditions, such as deep vein thrombosis, cerebral infarct, pulmonary infarct, skin ulcers, renal failure, and habitual abortion, are thought to be associated with the antiphospholipid syndrome. The authors describe a 32-year-old woman who had characteristics of the antiphospholipid syndrome including increased immunoglobulin G-cardiolipin antibody titers, iliofemoral vein thrombosis, pulmonary embolism, headache, visual disturbances, and habitual abortion. During hospitalization, she suddenly experienced right-sided weakness. A Tc-99m HMPAO brain scan showed the probability of a transient ischemic attack in the left frontotemporal cortex.     

Mesenteric vein thrombosis: CT identification

Superior mesenteric vein thrombosis was identified on computed tomographic scans in six patients. In each case, contrast-enhanced scans showed a high-density superior mesenteric vein wall surrounding a central filing defect. Four of the six patients had isolated superior mesenteric vein thrombosis. A fifth patient had associated portal vein and splenic vein thrombosis, and the sixth patient had associated portal vein and inferior vena cava thrombosis. The diagnosis of superior mesenteric vein thrombosis was confirmed by angiography in two patients and by surgery in a third. One of the six patients had acute ischemic bowel disease. The other five patients did not have acute ischemic bowel symptoms associated with their venous occlusion. This study defines the computed tomographic appearance of mesenteric vein thrombosis. A dense venous wall surrounding a central lucency representing blood clot was present in all six cases.     

Agenesis of the infrarenal inferior vena cava with thrombosis of the renal vein in a fetus: a case report

Agenesis of the inferior vena cava, especially of the infrarenal segment, is exceptional. This condition is thought to result from thrombosis during gestation rather than from a true congenital malformation. Agenesis of the inferior vena cava can be associated with renal vein thrombosis, which in turn is related to suprarenal hemorrhage in the fetus. We present a case of agenesis of the inferior vena cava with preservation of the hepatic segment, thrombosis of the left renal vein, and secondary bilateral suprarenal hemorrhage diagnosed prenatally using sonography and magnetic resonance imaging.     

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.     

Relationship between various patterns of transient increased hepatic attenuation on CT and portal vein thrombosis related to acute cholecystitis

OBJECTIVE: We sought to investigate the prevalence of portal vein thrombosis in patients with acute cholecystitis and the relationship between portal vein thrombosis and the various patterns of transient increased hepatic attenuation on CT. MATERIALS AND METHODS: We studied 72 of 107 patients with acute cholecystitis who, during a 3-year period, underwent dual-phase contrast-enhanced CT before percutaneous cholecystostomy or cholecystectomy. CT scans were retrospectively reviewed for the presence of portal vein thrombosis and location of the thrombi and for patterns of transient increased hepatic attenuation, which were classified as either pericholecystic, segmental, or mixed. RESULTS: Portal vein thrombi (two in hepatic segment IV, three in the left portal vein, and one in the right posterior portal vein) were found in six (8.3%) of 72 patients, and in those patients, transient increased attenuation with a segmental (five patients) or mixed (one patient) pattern was seen on CT. The pattern of transient increased attenuation in the 54 patients without portal vein thrombosis was pericholecystic in 41 (75.9%) and mixed in 13 (24.1%). Nineteen patients had segmental distribution (segmental or mixed pattern) that in 31.6% (6/19) of the patients was associated with portal vein thrombosis. Segmental distribution was more frequently found in those patients who had acute cholecystitis with portal vein thrombosis than in those who had only acute cholecystitis (p = 0.001). CONCLUSION: In patients with acute cholecystitis, portal vein thrombosis is not uncommon. Patterns of transient increased hepatic attenuation were found to vary, depending on the presence or absence of portal vein thrombosis.     

Selective renal venography in patients with primary renal disease and the nephrotic syndrome

Fifteen patients with primary renal disease and renal vein thrombosis who presented with the nephrotic syndrome were investigated venographically. In 46% of the patients the cavogram was normal. Selective renal venography is necessary in such patients because the course of patients with renal vein thrombosis and membranous glomerulonephritis is identical to that of patients with membranous glomerolonephritis alone. Eighty per cent of our patients had membranous glomerulonephritis; renal vein thrombosis is now thought to be secondary to this disease.     

Renal imaging findings in renal vein thrombosis: a note of caution

Renal vein thrombosis is a relatively uncommon disease that is being recognized with increasing frequency owing to both modern angiographic techniques and noninvasive modalities such as magnetic resonance imaging and renal images. It is important to emphasize the various imaging manifestations of renal vein thrombosis, especially if a renal image precedes more invasive testing. The findings of a Tc-99m DTPA renal image with correlative images in a patient with documented renal vein thrombosis are discussed.     

膜性肾病并发肾静脉血栓的彩色多普勒超声表现分析

目的探讨膜性肾病患者并发肾静脉血栓的彩色多普勒超声表现及其临床意义。方法膜性肾病27例,用二维超声和彩色多普勒超声观察肾脏的大小、形态、内部回声及肾静脉内是否有血栓。结果 27例中左肾主静脉血栓形成6例,段支1例,右肾主静脉血栓形成3例,段支1例,双肾主静脉血栓形成1例,本组27例膜性肾病患者并发肾静脉血栓的发生率为44%。结论彩色多普勒超声可作为诊断肾静脉血栓的首选方法。     

Simultaneous thrombosis of superior mesenteric artery and superior mesenteric vein following chemotherapy: MDCT findings

A case of acute mesenteric ischemia due to thrombosis of superior mesenteric artery and vein in a 44-year-old woman following chemotherapy for invasive laryngeal carcinoma was diagnosed on a multi-detector CT scan. Although the link between malignancy and thromboembolism is widely recognized in patients with cancer, chemotherapy further elevates the risk of thrombosis. Acute mesenteric ischemia associated or not associated with chemotherapy rarely occurs in patients with cancer. Moreover, co-occurrence of superior mesenteric artery and superior mesenteric vein thrombosis is reported for the first time.     

Ovarian vein thrombosis as a first manifestation of COVID-19 infection

Coronavirus disease 2019 (COVID-19) infection is associated with high risk of venous thromboembolic events mainly pulmonary embolism or deep venous thrombosis of the lower limbs. Ovarian vein thrombosis is a rare and serious condition usually seen in the immediate postpartum period and other conditions including pelvic inflammatory diseases, gynecological malignancies, hypercoagulable states, and few cases to date have reported ovarian vein thrombosis as a complication of COVID-19 infection. Patient with ovarian vein thrombosis usually presents with fever and lower abdominal pain that can mimic acute surgical abdomen and high index of suspicion is required for diagnosis. We report a case of a 41-year-old Asian female presented to our hospital with fever and acute lower abdominal pain. Laboratory findings show positive COVID-19 test and high D-dimer. Patient underwent computed tomography of the abdomen and pelvis and a confirmed diagnosis of right ovarian vein thrombosis was made. Patient was treated with anticoagulation and empirical antibiotics and her symptoms have significantly improved.     

Aorta-Left Renal Vein Fistula Complicating an Aortic Aneurysm: Preoperative and Postoperative Multislice CT Findings

Fistulas complicating an abdominal aortic aneurysm (AAA) are rare, and fistulas involving the left renal vein are particularly uncommon. We highlight here a fistula between an infrarenal aortic aneurysm and a retroaortic left renal vein, revealed by left flank pain associated with hematuria and acute renal failure. The multislice CT angiography performed in this 68-year-old patient revealed communication and equal enhancement between the aorta and the left gonadic vein, suggesting the presence of a fistula. The three-dimensional VRT reconstructions presented in this case were of great value in the preoperative planning, enabling immediate visualization of this unusual feature. Alternative diagnoses to consider when encountering this clinical presentation are reviewed.     

肾病综合征合并肾静脉血栓的介入性溶栓治疗

目的　探讨经肾动脉、肾静脉置管 ,区域性溶栓对“肾病综合征”(NS)合并肾静脉血栓的治疗作用。方法　 12例经肾静脉造影确诊有肾静脉血栓形成的肾病综合征患者 ,用介入性经皮穿刺插管技术 ,将导管插入到肾动脉及肾静脉 ,固定导管 ,用微泵持续 7～ 14d区域灌注尿激酶进行溶栓治疗。结果　 12例区域溶栓患者 ,溶栓后 7～ 14d颜面部水肿、双下肢水肿、腹水等显著好转 ,每日尿量增加 ,体重减轻 ,肾功能逐渐恢复 ,急性期症状改善非常明显 ,随访并继续用常规方法治疗 3～ 6个月 ,达临床治愈效果。结论　经肾动脉及肾静脉分别置管持续区域灌注尿激酶治疗NS合并肾静脉血栓见效快、疗效好、不良反应少 ,应加以推广应用     

Bone scan detection of renal vein thrombosis secondary to hypernephroma

Detection of renal vein thrombosis with osseous scintigraphy has been reported previously. An additional case is presented that is secondary to a hypernephroma. The observation is significant, it is known that patients with hypernephroma in addition to renal vein thrombosis have a worse prognosis.     

Renal scintigraphic findings in a case of transplant renal vein thrombosis

Renal vein thrombosis is a rare complication of renal transplantation. The scintigraphic features of a documented case of renal vein thrombosis studied with Tc-99m DTPA and the differential diagnosis relevant to these findings are discussed.     

Catheter-directed thrombectomy and thrombolysis for acute renal vein thrombosis

PURPOSE: To evaluate the technical success and clinical outcome of the percutaneous treatment of acute renal vein thrombosis (RVT). MATERIALS AND METHODS: Retrospective review was conducted of all patients with acute RVT treated with percutaneous catheter-directed thrombectomy with or without thrombolysis at one institution between 2000 and 2004. Demographics, comorbid conditions, and clinical outcomes associated with therapy were assessed. RESULTS: Seven thrombosed renal veins in six patients (mean age, 51.5 +/- 18.8 years) were treated with percutaneous catheter-directed thrombectomy/thrombolysis. Thrombosed renal veins included two allografts and five native veins, and diagnosis was confirmed in all cases by direct renal venography. Inferior vena cava thrombosis was the cause of RVT in one patient, and glomerulopathy was the cause in the remaining patients. Percutaneous mechanical thrombectomy was performed in all cases, and five renal veins were additionally treated with thrombolysis for a mean duration of 22.1 +/- 21.0 hours. Restoration of flow to renal veins was achieved in all thrombosed renal veins. Clinical improvement occurred in all patients: the mean serum creatinine level improved from a preoperative level of 3.3 +/- 1.92 mg/dL to a postoperative level of 1.92 +/- 1.32 mg/dL (P = .008). Mean glomerular filtration rate improved from a preoperative level of 30.8 +/- 23.0 mL/min per 1.73 m(2) to 64.2 +/- 52.4 mL/min per 1.73 m(2) (P = .04). There were no pulmonary emboli or hemorrhagic complications, and no RVT recurrence was documented during a median follow-up of 22.5 months. CONCLUSIONS: Percutaneous catheter-directed thrombectomy with or without thrombolysis for acute RVT is associated with a rapid improvement in renal function and low incidence of morbidity. It is feasible for native and allograft renal veins and should be considered in patients with acute RVT, particularly in the setting of deteriorating renal function.