Retroaortic left renal vein: multidetector computed tomography angiography findings and its clinical importance

PURPOSE: To evaluate the appearance, type, frequency, and clinical importance of retroaortic left renal vein (RLRV) in patients examined with multidetector computed tomography (MDCT) angiography. Material AND METHODS: A total of 1856 patients who underwent CT with urological symptoms (hematuria, flank and abdominal pain, left gonadal vein varicocele) (n = 889) or with symptoms other than urological ones (n = 967) were prospectively evaluated for the presence of RLRV. CT was performed with 110 ml of iodinated contrast material through the antecubital vein at a rate of 3.5 ml/s. Late arterial and early venous phase volumetric data sets were acquired at 30 and 65 s, respectively, from the start of the intravenous injection of contrast medium. In addition to axial images, multiplanar reconstructions (MPR), maximum-intensity projection (MIP), and three-dimensional volume-rendering (3D VR) images were used to assess left renal vein anomalies. Left renal vein anomalies were classified into four types according to their appearance: I) RLRV joining the inferior vena cava (IVC) in the orthotopic position; II) RLRV joining the IVC at level L4-L5; III) circumaortic or collar left renal vein; IV) RLRV joining the left common iliac vein. RESULTS: RLRV was detected in 68 (3.6%) of the 1856 patients, with 26, 22, 17, and three of types I, II, III, and IV, respectively. Forty-four of the 68 patients with RLRV (65%) were in the group with urological symptoms, while 24 patients (35%) were in the group without urological symptoms. Compression of the RLRV was found in 16 patients in the urological symptoms group, while compression was detected in only three patients in the other group. This difference was statistically significant (P<0.05). The most common urological symptom was hematuria. The frequency of urological symptoms was higher in groups II and IV compared to the other groups. CONCLUSION: MDCT angiography with axial, MPR, MIP, and 3D VR images is effective in the detection of vascular renal anomalies such as RLRV. Diagnosing RLRV and differentiating it from other pathologic conditions causing hematuria is important in order to avoid complications during retroperitoneal surgery or interventional procedures.     

Compression of the left common iliac vein in asymptomatic subjects and patients with left iliofemoral deep vein thrombosis

PURPOSE: To retrospectively evaluate compression of the left common iliac vein as demonstrated at computed tomography (CT) in patients with iliofemoral deep vein thrombosis due to iliac vein compression syndrome (IVCS) and compare compression ratios with those of asymptomatic subjects. MATERIALS AND METHODS: Between March 2003 and June 2007, compression of the left common iliac vein by the right common iliac artery, as demonstrated with CT, in 34 patients (25 women and nine men; mean age, 51 years; age range, 21-79 years) with IVCS was retrospectively evaluated. Compression ratios were compared with those of 34 age- and sex-matched asymptomatic subjects. A t test was used to compare the compression ratios. RESULTS: The percentages of compression of the left common iliac vein were 45%-100% (mean, 74% +/- 17) for patients with IVCS and 0%-68% (mean, 28% +/- 20) for control subjects (P < .05). Of the 34 patients with IVCS, 11 (32%) had less than 70% compression and 23 (68%) had at least 70% compression. CONCLUSIONS: There was considerable overlap between the degree of compression in patients with IVCS and control subjects. Compression of the left common iliac vein was significantly more prominent in patients with lower extremity deep vein thrombosis due to IVCS when compared with control subjects. Compression in excess of 70% as demonstrated at CT can be helpful for identifying possible underlying IVCS in patients with a left lower extremity deep vein thrombosis.     

Unilateral left leg edema: A variation of the May-Thurner syndrome

A single patient with left leg edema was examined with venography and computed tomography. A tortuous left common iliac artery was found to be compressing the left common iliac vein, causing near total obstruction of the left iliac vein. Hemodynamic pressure measurements confirmed the significance of the obstruction.     

Retroaortic left renal vein with renal vein hypertension causing hematuria

We describe a case of retroaortic left renal vein with hematuria. In this case, pullback pressure from the retroaortic left renal vein to the inferior vena cava revealed left renal vein hypertension according to criteria of the “nutcracker phenomenon.” We stress that left renal vein anomaly including retroaortic left renal vein can cause clinical symptoms such as hematuria.     

Computed tomography findings in 10 cases of iliac vein compression (May-Thurner) syndrome

OBJECTIVE: To present the computed tomography (CT) findings for the iliac veins of 10 patients who had left-sided lower extremity deep vein thrombosis due to iliac vein compression syndrome. MATERIALS AND METHODS: The CT findings for 10 cases of left-sided acute or chronic deep vein thrombosis caused by iliac vein compression syndrome were retrospectively evaluated. The patients were five women and five men (mean age+/-S.D., 49.9+/-15.6 years). In each patient with iliac vein compression syndrome, the diagnosis of the compression was established by venography performed during endovascular treatment. Diameter of the left common iliac vein was also measured in 14 control subjects without any lower extremity venous disease for comparison. RESULTS: In all 10 cases, CT images in the transverse plane demonstrated the left common iliac vein being compressed by the overlying right common iliac artery. The mean diameter at the origin of the left common iliac vein (3.5 mm) in patients group was much smaller than the mean diameter of the same vein (11.5 mm) in the control group (p<0.01). The mean percent stenosis of the left common iliac vein due to compression by the artery was 68%. CONCLUSION: Pelvic CT images in the transverse plane are useful for detecting iliac vein compression by the overlying right common iliac artery in patients with left-sided deep vein thrombosis. Radiologists should be aware of this imaging finding of iliac vein compression by the artery where the inferior vena cava bifurcates into the common iliac veins.     

Hemodynamic investigation of the left renal vein in pediatric varicocele: Doppler US, venography, and pressure measurements

PURPOSE: To evaluate prospectively the hemodynamic state of the left renal vein with Doppler ultrasonography (US) and venography in pediatric patients with varicocele to assess the "nutcracker phenomenon." MATERIALS AND METHODS: The institutional review board considered this study ethically sound, and parental informed consent was obtained for all subjects. Doppler US of the left renal vein was performed in 27 consecutive boys with varicocele (age range, 7-15 years; mean, 11.9 years) and in 20 boys without varicocele as control subjects (age range, 7-17 years; mean, 11.4 years). Doppler US was used to evaluate left renal vein diameters and peak velocities in the proximal left renal vein near the renal hilum and in the left renal vein between the aorta and superior mesenteric artery (aortomesenteric portion). The diameter ratios and peak velocity ratios between two sites were obtained. For statistical comparison of results, the t test was used. Left renal venography and renocaval pressure measurement were performed in 13 patients with varicocele. The Fisher exact test was used to evaluate the associations between the nutcracker phenomenon (renocaval pressure gradient >/=3 mm Hg) and the development of collateral veins. RESULTS: The diameters of the proximal left renal vein and the peak velocities in the aortomesenteric portion of the left renal vein were significantly different between the varicocele group and the control group (P < .001). The diameter ratios (5.7 +/- 1.8 [standard deviation]) and peak velocity ratios (5.2 +/- 2.6) in patients with varicocele were significantly higher than those in control subjects (3.5 +/- 1.0 and 3.1 +/- 0.8, respectively) (P < .005). According to findings at left renal venography (n = 13), 10 patients (77%) met the criteria for the nutcracker phenomenon. The nutcracker phenomenon was significantly associated with the development of collateral veins (P = .035). CONCLUSION: Doppler US and venography of the left renal vein can show hemodynamic changes of the left renal vein and depict the presence of the nutcracker phenomenon in pediatric varicocele.     

Acute iliofemoral deep vein thrombosis: evaluation of underlying anatomic abnormalities by spiral CT venography

PURPOSE: To evaluate the spectrum of underlying anatomic abnormalities in iliofemoral deep vein thrombosis (DVT) by spiral computed tomographic (CT) venography. MATERIALS AND METHODS: During the past 4 years, 56 patients with acute iliofemoral DVT have been evaluated by CT venography at our institution. Forty-four patients had left-sided DVT, nine had right-sided DVT, and the remaining three had DVT in both extremities. CT venography was performed with use of 2.5-3.2-mm x-ray beam collimation and a 1.25-2.0-mm reconstruction interval. Spiral scans were initiated 5 minutes after intravenous contrast medium injection. The CT venograms were correlated with catheter venograms. In addition, with use of axial sections and their three-dimensional reconstructions, including multiplanar reformation and volume rendering, the presence or absence of central obstructing lesions and their causes were evaluated. RESULTS: Among 44 patients with left-sided DVT, 37 had significant anatomic abnormalities in their iliofemoral veins or inferior vena cava (IVC). The most common lesion was left common iliac vein compression by the right common iliac artery (n = 27; exaggerated by a bony spur in nine and associated with extrinsic compression by the left internal iliac artery in two). Of the nine patients with right-sided DVT, six had significant anatomic abnormalities including encasement or extrinsic compression of their iliac veins by various causes (n = 3) and venous stricture without extrinsic lesions (n = 3). Among three patients with DVT in both extremities, two had anatomic abnormalities in the IVC. Therefore, 45 of 56 patients had anatomic abnormalities central to the thrombosed deep veins. CONCLUSION: The majority of patients with acute iliofemoral DVT had underlying anatomic abnormalities. The presence of central stenosis or obstruction and their causes can be evaluated by spiral CT venography.     

Ultrasonographic diagnosis of iliac vein compression (May-Thurner) syndrome

Iliac vein compression syndrome (IVCS), also known as May-Thurner syndrome, is the result of compression of the left common iliac vein between the right common iliac artery and overlying vertebrae. The most common clinical presentation is left lower extremity deep vein thrombosis. Rarely, a patient with IVCS can present with obstruction of venous outflow, without deep vein thrombosis. Iliac vein compression, with or without thrombosis, should be treated if symptomatic. We present a patient with IVCS that was initially diagnosed with transabdominal ultrasonography (US), and then confirmed with computed tomography and venography with pressure measurements. We believe this is the first report of an IVCS patient diagnosed with US.     

Congenital absence of portal vein with nodular regenerative hyperplasia of the liver

Congenital absence of the portal vein is a very rare anomaly. The intestinal and splenic venous drainage bypasses the liver and drain into the inferior vena cava (IVC). Two cases of such anomaly are described. Both cases were investigated by US coupled with echo-colour Doppler examination, CT and MR imaging, followed by digital subtraction angiography (DSA) and liver biopsy. In the first case the splenic and superior mesenteric vein formed a venous trunk which emptied directly into the IVC; in the second case, the splanchnic blood flowed into a dilated hepatofugal inferior mesenteric vein which connected to the left internal iliac vein. In both cases nodular regenerative hyperplasia of the liver was present, presumably due to an abnormal hepatic cell response to the absent portal flow. The particular contribution of MR imaging to the diagnosis of both vascular abnormalities and liver parenchyma derangement and its advantages over the other diagnostic techniques is emphasized. The clinical and radiological features of 17 previously reported cases are reviewed. Received: 22 September 1998; Revised: 21 January 1999; Accepted: 22 April 1999     

Diagnosing iliofemoral vein occlusion from radionuclide blood pool venography

There have been reports regarding the efficacy of Tc-99m labeled RBC venograms. The authors have found that potentially dangerous iliac vein occlusions can be missed unless especially careful attention is paid in looking for any asymmetry of the iliac vessels with respect to intensity, thickness, and/or definition, along the whole or at least 50% of one of the vessel's length, and the presence or absence of blood pool activity in the most proximal portion of the left common iliac vein, i.e., whether the activity arises from the IVC or the aorta. Eight (21%) of 38 consecutive labeled RBC venograms performed at this institution over six months produced findings that met criteria and/or. Iliofemoral vein occlusion was confirmed in six of the eight patients (16% of all patients). Thus, while the above criteria are not pathognomonic for iliofemoral vein occlusion, their rigid application has enabled the authors to detect a significant proportion of patients with iliofemoral occlusions which would otherwise have gone undetected. All eight cases were confirmed by further workup with direct injection radionuclide venography or contrast venography.     

Congenital absence of the horizontal portion of the left portal vein: ultrasound findings

Congenital absence of the horizontal portion of the left portal vein is very rare and has been very reported sporadically. We present three such cases referred from other hospitals with a diagnosis of intrahepatic vascular anomaly. Color Doppler ultrasound not only confirmed the diagnosis but also allowed a quantitative measurement of blood flow in these cases. Although it is a very rare condition, knowledge of the ultrasound and color Doppler findings helps in establishing the diagnosis of this congenital anomaly. Received: 9 July 1999; Revised: 25 October 1999; Accepted: 25 October 1999     

Direct contrast-enhanced MR venography in the diagnosis of May-Thurner Syndrome

Visualization of lower extremity veins with MR venography still needs improvement. The latest advancement is direct contrast-enhanced 3D MR venography which is based on display of venous system during direct injection of paramagnetic extracellular contrast agent into pedal veins. We used automated injection of contrast agent with a power injector makings this application simpler and faster, achieved to show the iliac vein compression syndrome and post-thrombotic changes of the left iliac and femoral veins.     

先天性髂静脉受压综合征的静脉造影诊断

目的:探讨先天性髂静脉受压综合征的静脉造影诊断价值。材料和方法:回顾性分析经手术证实的18例先天性髂静脉受压综合征,其中8例行股静脉插管造影。结果:18例先天性髂静脉受压综合征的髂静脉造影表现均为静脉血管受压改变及侧支循环的形成。结论:先天性髂静脉受压综合征的髂静脉造影表现较典型,改变传统造影方式是发现并诊断C IVCS的关键。     

Preaortic iliac confluence (marsupial vena cava): report of 4 cases

Congenital anomalies of the inferior vena cava (IVC) can represent a difficult for abdominal surgeries, and the radiologist must be aware even of the less common of these anatomical variations. Preaortic iliac venous confluence, also known as marsupial vena cava, is a rare congenital anomaly of the development of the IVC in which the IVC or the left common iliac vein is located anterior to the aortic bifurcation or the right common iliac artery. We report 4 cases of marsupial vena cava detected on multidetector computed tomography examinations in asymptomatic patients and discuss that this congenital anomaly can be recognized more frequently with the use of this new technique based on thinner images.     

Embolization of the internal spermatic vein in varicocele: Significance of venous pressure

Embolization of the left internal spermatic vein using spring-coils was performed in 20 patients with varicocele following pressure measurement of the left renal vein and inferior vena cava. During the follow-up of 16–24 months, there was no recurrence in 16 patients with pressure difference less than 3 mmHg; however, there were two recurrences in 4 patients with pressure difference greater than 4 mmHg and opacified adrenal or ureteral veins on venography. We conclude that a significant pressure difference between left renal vein and inferior vena cava, and opacification of adrenal or ureteral veins on left renal venography may be poor prognostic signs of recurrence of varicocele following embolization.     

Aberrant left brachiocephalic vein: CT imaging findings and embryologic correlation

Computed tomography was utilized to evaluate aberrant left brachiocephalic vein (ALBCV), an infrequently discussed congenital vascular anomaly among Chinese people. Associated vascular variation and possible embryonic correlation are discussed. Since 1990, a total of 14 cases of ALBCV have been reported in patients receiving CT scan of chest, and was mainly an incidental diagnosis. One case was confirmed angiographically and two others were confirmed by magnetic resonance imaging. Emphasis was placed on the entry of the azygos vein into the superior vena cava (SVC), the length of the SVC, and the presence of other cardiovascular abnormalities. Of the 14 cases of ALBCV, the level of azygos vein entry was higher than the origin of the SVC in 7 cases: 4 were approximately the same level and 3 were lower. The average length of the SVC was approximately 5.6 cm shorter than that of the general population, which is approximately 7.0 cm. Three cases had associated vascular anomaly. Most cases of ALBCV had azygos vein drainage level higher than or equal to the origin of the SVC. Right-sided aorta is one of the causes giving rise to the ALBCV during embryonic development. The CT scan remains a definitive diagnostic modality for ALBCV. Received: 20 January 1998; Revision received: 22 June 1998; Accepted: 23 June 1998     

Radionuclide venography as a clue to the diagnosis of Budd-Chiari syndrome

A patient was examined with radionuclide venography (RVG) to investigate unilateral leg oedema which might be due to deep vein thrombosis. RVG with Tc-99m MAA demonstrated no findings to suggest deep vein thrombosis of the right leg. However, collateral flow derived from the left common iliac vein and truncated inferior vena cava (IVC) were revealed. Contrast venography confirmed the obstruction of IVC and collateral flow from the left common iliac vein to the left ascending lumbar vein. It also showed the obstruction of hepatic veins and the patient was finally diagnosed as Budd-Chiari syndrome. Although unilateral leg oedema is an atypical symptom in Budd-Chiari syndrome, the findings on RVG led us to conduct further imaging studies to reach the diagnosis.     

Intravascular ultrasound in the diagnosis and treatment of iliac vein compression (May-Thurner) syndrome

Intravascular ultrasound (IVUS) imaging and venography of the left common femoral and iliac veins were performed in 16 patients. The studies were evaluated for the anatomic cause of obstruction and how IVUS influenced endovascular management. IVUS demonstrated the cause of vessel compression in all 16 patients. Other findings, such as associated thrombus and guide wire localization within the residual vessel lumen, can modify the approach to intervention in as many as 50% of patients. IVUS is a useful adjunct in the diagnosis and endovascular management of iliac vein compression syndrome.     

MR imaging of double chambered left ventricle

Double chambered left ventricle is a very rare anomaly within the broader category of "subdivision of the left ventricular cavity," which includes the relatively more common congenital aneurysms and diverticulae. We report a case of an adolescent with double chambered left ventricle that MR clearly delineated, resulting in successful surgical correction.     

Successful Endovascular Treatment of Iliac Vein Compression (May-Thurner) Syndrome in a Pediatric Patient

A 10-year-old boy presented to our clinic with left lower extremity swelling present for 1 year with deterioration of symptoms during the prior month. Laboratory investigation for deep vein thrombosis was negative. Venography and computed tomography scan of the pelvis showed compression of the left common iliac vein by the right common iliac artery. A diagnosis of iliac vein compression syndrome was made. After venography, endovascular treatment was planned. The stenosis did not respond to balloon dilatation and a 12 mm Wallstent was placed with successful outcome. The patient’s symptoms improved but did not resolve completely, probably due to a chronically occluded left superficial femoral vein that did not respond to endovascular recanalization. To the best of our knowledge, this is the first case of successful endovascular treatment of iliac vein compression syndrome with stent placement in a pediatric patient.