Magnetic resonance venography to evaluate cerebral sinovenous thrombosis in infants receiving therapeutic hypothermia.

BACKGROUND: The incidence of cerebral sinovenous thrombosis (CSVT) in infants receiving therapeutic hypothermia for neonatal encephalopathy remains controversial. The aim of this study was to identify if the routine use of magnetic resonance venography (MRV) in term-born infants receiving hypothermia is associated with diagnostic identification of CSVT. METHODS: We performed a retrospective review of 291 infants who received therapeutic hypothermia from January 2014 to March 2020. Demographic and clinical data, as well as the incidence of CSVT, were compared between infants born before and after adding routine MRV to post-rewarming magnetic resonance imaging (MRI). RESULTS: Before routine inclusion of MRV, 209 babies were cooled, and 25 (12%) underwent MRV. Only one baby (0.5%) was diagnosed with CSVT in that period, and it was detected by structural MRI, then confirmed with MRV. After the inclusion of routine MRV, 82 infants were cooled. Of these, 74 (90%) had MRV and none were diagnosed with CSVT. CONCLUSION: CSVT is uncommon in our cohort of infants receiving therapeutic hypothermia for neonatal encephalopathy. Inclusion of routine MRV in the post-rewarming imaging protocol was not associated with increased detection of CSVT in this population. IMPACT: Cerebral sinovenous thrombosis (CSVT) in infants with NE receiving TH may not be as common as previously indicated. The addition of MRV to routine post-rewarming imaging protocol did not lead to increased detection of CSVT in infants with NE. Asymmetry on MRV of the transverse sinus is a common anatomic variant. MRI alone may be sufficient in indicating the presence of CSVT.

Acute left iliofemoral vein thrombosis: Comparison between simple and bony May-Thurner syndrome in CT venography.

OBJECTIVES: To explore the etiology of May-Thurner syndrome (MTS) with acute iliofemoral deep vein thrombosis (DVT) regarding imaging findings and clinical features. METHODS: We retrospectively analyzed 57 patients with acute left iliofemoral DVT from 2015 to 2020. The diameter of left common iliac vein (LCIV) at the maximal compression site and its percent compression regarding the average diameter of the uncompressed iliac vein were recorded in central and distal portions of the LCIV according to the location in the quadrant of lumbar vertebral body. Compression was categorized into simple and bony MTS; Simple MTS as LCIV compressed by the right common iliac artery (RCIA) versus Bony MTS as LCIV by lower lumbar degenerative changes regardless of RCIA compression. Initial computed tomographic venography (CTV) regarding chronic change of LCIV such as fibrotic atrophy or cordlike obliteration, extent of thrombus, and lumbar degenerative changes were evaluated. Therapeutic effect after initial therapy was assessed in follow-up CTVs after 3-6 months. RESULTS: All patients showed LCIV compression with 19 simple MTS (mean age, 42.8 ± 14.1 years [23-67 years]; 12 females; symptom for 4.4 ± 5.5 days) and 38 bony MTS (mean age, 73.0 ± 10.2 years [49-85 years]; 26 females; symptom for 5.5 ± 4.8 days). There was significant difference in age (p < .001) and no significant difference in sex or symptom duration between two groups (p = .691 and 0.415, respectively). All simple MTS showed compression only in the central LCIV and half of bony MTS showed compression in both central and distal LCIV (p < .001). Among the lumbar degenerative changes, symmetric anterolateral osteophyte (p < .001) and asymmetric osteophyte (p < .001) were significantly associated with bony MTS, but not scoliosis (p = .799), compared to simple MTS. Although there was no significant difference in chronic change of LCIV, thrombosis extent, and therapeutic effect between two groups (p > .05), chronic change of LCIV showed significant difference between single and dual compression (23.7% vs. 57.9%, p = .024) and residual thrombus after initial therapy was occurred in 21.1% of single compression and 47.4% in dual compression with non-significant trend (p = .082). CONCLUSION: Bony MTS related to lumbar degenerative changes with acute iliofemoral DVT occurs in older patients, presenting more than one stenosis at LCIV, inducing more chronic change with possibly weaker therapeutic effect than simple MTS.

Silent Pulmonary Embolism in Deep Vein Thrombosis: Relationship and Risk Factors.

PURPOSE: This study aimed to evaluate risk factors for silent pulmonary embolism (PE) in symptomatic deep vein thrombosis (DVT) and investigate the relationship between DVT and silent PE. METHODS: This was a single-centre, retrospective cohort study. Between 5 January 2015 and 31 December 2021, consecutive patients with symptomatic DVT received CT pulmonary angiography and CT venography were analyzed. Patient demographics, comorbidities, risk factors, and image findings were analyzed. The group differences were compared using a Chi-square test, Fisher's exact test, independent t test, or Mann-Whitney U test. Multivariant regression was used to determine predictive factors for silent PE. RESULTS: A total of 355 patients (mean age, 60.5 ± 16.6 years) were included. The incidence of silent PE was 43.1%. The main or lobar pulmonary arteries were affected in 53.6% of patients, which is more often found in iliofemoral DVTs (56.6% vs 26.7%, p = .027). The multivariant analysis showed male patients (p = .042; OR 1.59; 95% CI, 1.02-2.50), inferior vena cava involvement (p = .043; OR 1.81; 95% CI, 1.02-3.20) and D-dimer value > 3.82 µg/ml (p < .001; OR 2.32; 95% CI, 1.43-3.77) were risk factors for silent PE. Unilateral DVT patients with ipsilateral iliac vein compression had a lower incidence of silent PE (28.8% vs 52.9%, p < .001). CONCLUSION: Iliofemoral DVT was associated with a more proximal PE. The male patients, inferior vena cava involvement, and D-dimer > 3.82 µg/ml were risk factors for silent PE. Ipsilateral iliac vein compression reduced the incidence of silent PE.

[Nutcracker syndrome: a cause of unexplained hematuria]. / Syndrome du casse-noisette : une cause d'hématurie inexpliquée.

Hematuria is frequently encountered in clinical practice. Its diagnostic spectrum is wide: urinary tract infection, lithiasis, malignant tumor and nephropathy. In the absence of one of these causes, the nutcracker syndrome must be evoked. It results from compression of the left renal vein between the abdominal aorta and the superior mesenteric artery. Knowing how to diagnose it can avoid morbid consequences (chronic renal disease, renal vein thrombosis). In addition to hematuria, its main symptoms are left lumbago, varicoceles, and orthostatic proteinuria. The clinical picture and complementary examinations (ultrasound-doppler, computed tomography angiography, magnetic resonance angiography, and phlebography) generally allow the diagnosis to be made. Treatment varies according to age and severity of symptoms.

L'hématurie est fréquemment rencontrée en pratique clinique. Son spectre diagnostique est large : infection urinaire, lithiase, tumeur maligne et néphropathie. En l'absence de l'une de ces causes, le syndrome du casse-noisette doit être évoqué. Il résulte de la compression de la veine rénale gauche entre l'aorte abdominale et l'artère mésentérique supérieure. Savoir le diagnostiquer permet d'éviter des conséquences morbides (maladie rénale chronique, thrombose veineuse rénale). Outre l'hématurie, ses principaux symptômes sont la lombalgie gauche, les varicocèles et la protéinurie orthostatique. Le tableau clinique et les examens complémentaires (échographie-doppler, angioscanner, angio-IRM et phlébographie) permettent généralement de poser le diagnostic. Le traitement varie en fonction de l'âge et de la sévérité des symptômes.

Usefulness of three-dimensional computed tomography venography differentiating calvarium subperiosteal hematoma crossing the suture lines due to hair pulling from subgaleal hematoma: case report and review of the literature.

This case showed a 13-year-old boy presented with calvarium subperiosteal hematoma crossing the suture lines caused by hair pulling, and 3D-CTV can differentiate calvarium subperiosteal hematoma crossing the suture lines from subgaleal hematoma. He was treated successfully.

May Thurner syndrome: description of a case with unusual clinical onset.

May-Thurner syndrome (MTS) is a congenital vascular alteration that is part of a restricted category of very rare vascular syndromes that have in common the compression of an arterial or venous vessel. MTS, first described in 1957, is due to compression of the left common iliac vein against the lumbar spine by the adjacent common iliac artery. It can cause chronic thrombosis of the left lower limb and can give edema, pain, claudication, thrombophlebitis, and, in severe cases, pulmonary embolism. Color Doppler and duplex Doppler ultrasound allow us to easily locate the deep vein thrombosis, to measure its extension, and to highlight the vascular changes typical of MTS: compression and consequent hypertension of the left common iliac vein. The therapy depends on the degree of venous stasis and on the presence of venous thrombosis; generally, it consists of the administration of short- or long-term anticoagulant and thrombolytic drugs. In cases of severe stenosis of the left common iliac vein, the first-choice treatment consists of positioning a vascular stent, which resolves compression and significantly reduces chronic thrombotic episodes. We describe a case of MTS with an unusual clinical onset with pulmonary embolism.

Brain venography performance following the pause of Ad.26.COV2.S COVID-19 vaccine administration.

Cases of cerebral venous thrombosis (CVT) associated with vaccine induced thrombotic thrombocytopenia (VITT) were reported following administration of the adenoviral vector COVID-19 vaccines, resulting in a pause in Ad.26.COV2.S vaccine administration in the United States, beginning on April 14, 2021. We aimed to quantify and characterize an anticipated increase in brain venograms performed in response to this pause. Brain venogram cases were retrospectively identified during the three-week period following the vaccine pause and during the same calendar period in 2019. For venograms performed in 2021, we compared COVID vaccinated to unvaccinated patients. There was a 262% increase in venograms performed between 2019 (n = 26) and 2021 (n = 94), compared to only a 19% increase in all radiologic studies. Fifty-seven percent of patients in 2021 had a history of COVID-19 vaccination, with the majority being Ad.26.COV2.S. All patients diagnosed with CVT were unvaccinated. COVID vaccinated patients lacked platelet or D-dimer measurements consistent with VITT. Significantly more vaccinated versus unvaccinated patients had a headache (94% vs 70%, p = 0.0014), but otherwise lacked compelling CVT presentations, such as decreased/altered consciousness (7% vs 23%, p = 0.036), neurologic deficit (28% vs 48%, p = 0.049), and current/recent pregnancy (2% vs 28%, p = 0.0003). We found a dramatic increase in brain venograms performed following publicity of rare COVID-19 vaccine associated CVT cases, with no CVTs identified in vaccinated patients. Clinicians should carefully consider if brain venogram performance is indicated in COVID-19 vaccinated patients lacking thrombocytopenia and D-dimer elevation, especially without other compelling CVT risk factors or symptoms.

When You Cannot Go With the Flow: A Case Report of May-Thurner Syndrome.

INTRODUCTION: May-Thurner syndrome (MTS) is caused by extrinsic compression of the left iliac venous system, most commonly between an overlying right iliac artery and fifth lumbar vertebra, and is seen mainly in women between 20 and 50 years of age. This compression may be asymptomatic but can lead to the formation of venous thrombi causing left lower extremity pain and swelling. CASE PRESENTATION: We report a case of MTS in a patient who initially presented with back and left lower extremity pain and swelling whose initial duplex venous ultrasound was negative for deep venous thrombus. Subsequent computed tomography (CT) revealed a venous thrombus of the left common, internal, and external iliac veins. DISCUSSION: In the case of unilateral lower extremity swelling with a negative initial duplex venous ultrasound, consider further investigation with CT venography to evaluate for possible MTS.

Analyzing Radiation Use during Transjugular Intrahepatic Portosystemic Shunt Creation.

Portal vein access during transjugular intrahepatic portosystemic shunt creation was examined in 11 patients. Radiation metrics (kerma area product, reference point air kerma, and fluoroscopy times) during portal vein access were significantly greater for conventional versus intravascular US-guided transjugular intrahepatic portosystemic shunt (54.8 mGy ∙ cm2 ± 27.6 vs 8.4 mGy ∙ cm2 ± 5.0, P = .009; 210.4 mGy ± 109.1 vs 29.5 mGy ± 18.4, P = .009; 19.1 min ± 8.6 vs 8.9 min ± 4.6, P = .04). Wedged hepatic venography is a major contributor to radiation exposure. Intravascular US guidance is associated with significantly reduced radiation use.

Fluoroscopy-guided axillary vein access vs cephalic vein access in pacemaker and defibrillator implantation: Randomized clinical trial of efficacy and safety.

INTRODUCTION: The most widespread venous sites of access for implantation intravenous implantable cardiac electronic device (CIED) are the cephalic and subclavian vein. Fluoroscopy-guided axillary venous access is an alternative, but efficacy and safety have not been studied under equal conditions. The aim of the present study is to compare the efficacy and safety of fluoroscopy-guided axillary vs cephalic vein access in CIED implant. METHODS AND RESULTS: Two hundred and forty patients were randomized to receive CIED implantation by the fluoroscopy-guided axillary vein access vs cephalic vein access. The implantation success, the procedure times and the complications were recorded. A comparison of the results of operators was made. The success rate of the randomized venous access was superior in the axillary group than in cephalic (98.3% vs 76.7%, P < .001). Time to access (6.8 ± 3.1 minute vs 13.1 ± 5.8 minutes, P < .001) and implantation duration was significantly shorter in the axillary group than in the cephalic group (42.3 ± 11.6 minutes vs 50.5 ± 13.3 minutes, P < .001). There was no difference in the incidence of complication and inter-operator success rate, complications rate and time to access. CONCLUSION: The fluoroscopy-guided axillary venous access is safe and has a better success rate and faster execution time compared with the cephalic vein access. When the results were compared among the study operators, neither in the axillary nor in the cephalic group there were differences in the success rate, the complication rate, and the time to access. TRIAL REGISTRATION: www.clinicaltrials.gov, NCT03860090.

Contrast venography vs. microwire assisted axillary venipuncture for cardiovascular implantable electronic device implantation.

Aims: This study was conducted to compare the safety and efficacy of microwire assisted technique with contrast venography guided axillary venipuncture in patients undergoing cardiovascular implantable electronic device (CIED) implantation. Methods and results: This prospective randomized study included 212 consecutive adult patients undergoing CIED implantation at our institute between 2013 and 2015. Patients were randomized to either venography guided technique (Group I; n = 105) or microwire assisted technique (Group II; n = 107) for axillary venipuncture. In Group I axillary venogram was used as a roadmap for guiding the puncture. In Group II, a 0.014 inch hydrophilic coronary guidewire ('microwire') was introduced through the ipsilateral antecubital vein and puncture needle was aimed to hit the microwire over the first or second rib. Outcome measures including technical success rates; number of attempts to successful puncture; puncture duration; fluoroscopy times and adverse events were compared in the two groups. Overall success rates were similar in both groups (97.4% in Group I and 100% in Group II, P = 0.061). We demonstrated significantly higher first attempt success rates; shorter puncture durations and fluoroscopy times; and lower number of attempts to successful puncture with microwire assisted technique (89.3% vs. 65.6%; 36.7 ± 23.1 s vs. 67.8 ± 44.9 s; 62.4 ± 35.3 s vs. 118.9 ± 63.2 s; and 1.21 ± 0.82 vs. 2.16 ± 1.54 respectively, P < 0.001). Adverse event rates were significantly lower with microwire assisted technique (0.9% vs. 8.6%, P = 0.009). Conclusion: Microwire assisted technique is a simple, quicker, safer and more efficacious alternative to contrast venography guided axillary venipuncture.

Development of radiation exposure in patients undergoing pulmonary vein isolation in Germany between 2007 and 2014: great potential to minimize radiation dosage.

AIM: The aim of this study was to analyze the radiation usage in patients undergoing pulmonary vein isolation (PVI) in Germany and to evaluate the possibility to reduce radiation dose. METHODS AND RESULTS: A total of 6617 patients with atrial fibrillation (AF) from the German ablation registry and the FREEZEplus registry (control group), who underwent first PVI between 2007 and 2014, were analyzed. In the second step, the effect of optimized conventional fluoroscopy and optimized 3D mapping use was evaluated in 526 consecutive patients with AF who underwent first PVI at the Klinikum Ludwigshafen (optimized group) between 2007 and 2014. In the control group, the median dose area product (DAP) for PVI was 34 Gy cm(2), and the median DAP rate was 1.3 Gy cm(2)/min. The DAP decreased from 37 to 28 Gy cm(2), whereas the DAP rate increased from 1.3 to 1.6 Gy cm(2)/min between 2007 and 2014. In the optimized group, optimized radiation application and use of 3D mapping resulted in a continuous decrease in the DAP from 67 to 2 Gy cm(2) and DAP rate from 1.0 to 0.2 Gy cm(2)/min. CONCLUSION: Currently, the median radiation exposure during PVI in Germany is 28 Gy cm(2). Optimized fluoroscopy by simple means can safely reduce the radiation dose to about 2 Gy cm(2) or even lower when using 3D mapping. Before introducing novel expensive technologies for radiation reduction optimizing of the conventional fluoroscopy is mandatory.

Comparative occupational radiation exposure between fixed and mobile imaging systems.

OBJECTIVE: Endovascular intervention exposes surgical staff to scattered radiation, which varies according to procedure and imaging equipment. The purpose of this study was to determine differences in occupational exposure between procedures performed with fixed imaging (FI) in an endovascular suite compared with conventional mobile imaging (MI) in a standard operating room. METHODS: A series of 116 endovascular cases were performed over a 4-month interval in a dedicated endovascular suite with FI and conventional operating room with MI. All cases were performed at a single institution and radiation dose was recorded using real-time dosimetry badges from Unfors RaySafe (Hopkinton, Mass). A dosimeter was mounted in each room to establish a radiation baseline. Staff dose was recorded using individual badges worn on the torso lead. Total mean air kerma (Kar; mGy, patient dose) and mean case dose (mSv, scattered radiation) were compared between rooms and across all staff positions for cases of varying complexity. Statistical analyses for all continuous variables were performed using t test and analysis of variance where appropriate. RESULTS: A total of 43 cases with MI and 73 cases with FI were performed by four vascular surgeons. Total mean Kar, and case dose were significantly higher with FI compared with MI. (mean ± standard error of the mean, 523 ± 49 mGy vs 98 ± 19 mGy; P < .00001; 0.77 ± 0.03 mSv vs 0.16 ± 0.08 mSv, P < .00001). Exposure for the primary surgeon and assistant was significantly higher with FI compared with MI. Mean exposure for all cases using either imaging modality, was significantly higher for the primary surgeon and assistant than for support staff (ie, nurse, radiology technologist) beyond 6 feet from the X-ray source, indicated according to one-way analysis of variance (MI: P < .00001; FI: P < .00001). Support staff exposure was negligible and did not differ between FI and MI. Room dose stratified according to case complexity (Kar) showed statistically significantly higher scattered radiation in FI vs MI across all quartiles. CONCLUSIONS: The scattered radiation is several-fold higher with FI than MI across all levels of case complexity. Radiation exposure decreases with distance from the radiation source, and is negligible outside of a 6-foot radius. Modern endovascular suites allow high-fidelity imaging, yet additional strategies to minimize exposure and occupational risk are needed.

Catheter venography for the assessment of internal jugular veins and azygous vein: position statement by expert panel of the International Society for Neurovascular Disease.

This document by an expert panel of the International Society for Neurovascular Disease is aimed at presenting current technique and interpretation of catheter venography of the internal jugular veins, azygous vein and other veins draining the central nervous system. Although interventionalists agree on general rules, significant differences exist in terms of details of venographic technique and interpretations of angiographic pictures. It is also suggested that debatable findings should be investigated using multimodal diagnostics. Finally, the authors recommend that any publication on chronic cerebrospinal venous insufficiency should include detailed description of venographic technique used, to facilitate a comparison of published results in this area.

Evaluation of deep vein thrombosis with reduced radiation and contrast material dose at computed tomography venography: clinical application of a combined iterative reconstruction and low-tube-voltage technique.

BACKGROUND: Computed tomography venography (CTV) is clinically useful and widely available for the detection of deep vein thrombosis. Disadvantages of CTV are the need for a larger amount of i.v. contrast material (CM) and radiation exposure. A low-tube-voltage technique with iterative reconstruction may overcome this problem. The aim of this study was to investigate the effects of hybrid iterative reconstruction (HIR) on image quality at low-tube-voltage CTV. METHODS AND RESULTS: Forty patients (26 women, 14 men; mean age, 59.2±18.3 years) underwent CTV under an 80- or 120-kV protocol (CT dose index volume=10.3 mGy vs. 14.9 mGy, CM dose=540 mgI/kg vs. 690 mgI/kg) on a 64-detector CT. Quantitative parameters (ie, venous attenuation, image noise, and contrast-to-noise ratio [CNR]) were calculated and the image quality was scored on a 4-point scale. In step 1, the 80- and 120-kV protocols were compared under filtered back projection (FBP). In step 2, the 80-kV protocol with HIR was compared with the 120-kV protocol with FBP. In step 1, the visual scores were significantly higher under the 120-kV protocol; there was no significant difference in CNR between the protocols. In step 2, CNR was significantly higher under the 80-kV protocol with HIR than the 120-kV protocol with FBP. The visual scores of the 2 protocols were comparable. CONCLUSIONS: The 80-kV CTV with HIR allows for a reduction in the radiation dose by 30% and the CM dose by 20% without image quality degradation.

A retrospective study of the value of indirect CT venography: a British perspective.

OBJECTIVE: The aim of this study was to establish the value of indirect CT venography (CTV) in clinical practice within the UK. METHODS: 804 combined CT pulmonary angiogram and CTV studies were retrospectively reviewed. CTV was performed 180 s after the injection of contrast using an incremental technique with a 5-mm collimation and a 5-cm interspace between images extending from the iliac crests to the tibial plateaus. RESULTS: 12.9% of studies had isolated pulmonary emboli (PE), 3.0% had both a PE and deep vein thrombosis (DVT) and 1.1% had an isolated DVT. The proportion of positive cases diagnosed by CTV alone was 6.6%. CONCLUSION: In a UK-based practice, the incidence and the proportion of isolated DVT diagnosed by CTV are lower than expected from published data. An analysis of possible causes for this is made within the paper.