CT Findings of Azygos Venous System: Congenital Variants and Acquired Structural Changes

The azygos venous system is a crucial conduit of the posterior thorax and potentially vital collateral pathway. However, it is often overlooked clinically and radiologically. This pictorial essay reviews the normal azygos venous anatomy and CT findings of congenital variations and structural changes associated with acquired pathologies.

Evaluation of an artificial intelligence-based system for echocardiographic estimation of right atrial pressure

Current noninvasive estimation of right atrial pressure (RAP) by inferior vena cava (IVC) measurement during echocardiography may have significant inter-rater variability due to different levels of observers' experience. Therefore, there is a need to develop new approaches to decrease the variability of IVC analysis and RAP estimation. This study aims to develop a fully automated artificial intelligence (AI)-based system for automated IVC analysis and RAP estimation. We presented a multi-stage AI system to identify the IVC view, select good quality images, delineate the IVC region and quantify its thickness, enabling temporal tracking of its diameter and collapsibility changes. The automated system was trained and tested on expert manual IVC and RAP reference measurements obtained from 255 patients during routine clinical workflow. The performance was evaluated using Pearson correlation and Bland-Altman analysis for IVC values, as well as macro accuracy and chi-square test for RAP values. Our results show an excellent agreement (r=0.96) between automatically computed versus manually measured IVC values, and Bland-Altman analysis showed a small bias of [Formula: see text]0.33 mm. Further, there is an excellent agreement ([Formula: see text]) between automatically estimated versus manually derived RAP values with a macro accuracy of 0.85. The proposed AI-based system accurately quantified IVC diameter, collapsibility index, both are used for RAP estimation. This automated system could serve as a paradigm to perform IVC analysis in routine echocardiography and support various cardiac diagnostic applications.

Luminal changes in patients with Inferior Vena Cava filters and development of chronic venous disease

INTRODUCTION

This study aimed to analyze the luminal changes in the iliocaval veins and their effects on the development of signs and symptoms of chronic venous disease manifesting from inferior vena cava filter placement.

METHODS

This was a retrospective observations study; deidentified patients with an Inferior Vena Cava (IVC) filter placed with subsequent luminal changes were included. All patients had a computerized tomography (CT) scan with or without ultrasound and those who underwent an intervention for the obstruction had also venography and intravascular ultrasound (IVUS). The diameter of IVC and iliac veins was measured from the near wall to the far wall. IVC diameters measured less than 12 mm were considered to be retractions. Signs and symptoms of chronic venous disease were obtained from patient charts and were reported according to the highest CEAP class. The data was analyzed using descriptive statistics, presenting diameter changes as a mean with standard deviation and a range of diameters included.

RESULTS

Overall, 76 patients were included in this study, of whom 66 had occlusion of the IVC or the Iliac veins. Luminal changes of the inferior vena cava were observed in all patients. A total of 58 patients presented with chronic post-thrombotic changes in both the inferior vena cava and iliac veins. There were 4 patients that had a luminal reduction with no filling defects or post-thrombotic changes. Average inferior vena cava diameter and iliac vein diameter was measured to be 8.3 ± 1.4 mm and 4.6 ± 1.4 mm, respectively. Patients most frequently presented with extremity swelling, but other signs such as venous ulceration or skin damage were observed.

CONCLUSION

Permanent luminal changes of the inferior vena cava and iliac veins were observed as a result of inferior vena cava filter placement and such patients commonly present with signs and symptoms of chronic venous disease. Together, with other known filter complications, these observations add more reasons for a timely retrieval. When such changes occur, patients' appropriate symptoms can be successfully treated. The permanent changes made by filter placement in the IVC and iliac veins further support filter retrieval in a timely fashion. The luminal changes induced by filter placement should be recognized early, particularly in symptomatic patients who can be safely treated with endovenous procedures.

Inferior Vena Cava Stenosis Following Orthotopic Liver Transplantation: Differentiating Points from False Positives

Orthotopic liver transplantation has become the treatment of choice for patients with end-stage liver disease. Various early or delayed vascular complications, including arterial pseudoaneurysm, thrombosis, or stenosis, and venous stenosis or occlusion, may lead to graft failure. Early detection and prompt management of such complications are essential to achieve successful transplantation and prevent the need for retransplantation. This report presents differentiating points, using computed tomography and digital subtraction angiography findings and measurement of pressure gradient across the stenotic lesion, that require immediate intervention in patients with inferior vena cava stenosis after orthotopic liver transplantation.

Missing Inferior Vena Cava on POCUS: A Case of Left-Sided IVC with Azygos Continuation

The merits of utilizing point of care ultrasound (POCUS) in acutely ill patients is leading to a widespread embrace. Assessment of IVC via POCUS as part of a comprehensive multi-organ approach can help guide volume tolerance. Anatomical/developmental variations of IVC can vary widely in prevalence. As the use of POCUS expands as a diagnostic modality, it is prudent for frontline POCUS users to be cognizant of the IVC anomalies. We present a case of left sided IVC with azygous continuation discovered with POCUS that was performed to assess the volume status of the patient. This case illustrates that the awareness of different anomalies of the IVC is necessary for POCUS users to prevent misinterpretation of aberrant vessels and avoid diagnostic pitfalls.

Conservative treatment vs thrombus removal for Iliofemoral vein thrombosis in patients with congenital abnormalities of the inferior vena cava: a case report and systematic review of the literature

Congenital abnormalities of the Inferior Vena Cava (IVC) should be suspected in cases of Deep Venous Thrombosis (DVT), especially in young patients, with no other risk factors and apparent causes. Currently, there is no guidance regarding the management of such patients. We report a case of Iliofemoral vein thrombosis in a young patient with congenital absence of the IVC that was successfully treated with catheter-directed thrombolysis (CDT) and perform a systematic review of the literature to identify evidence about the epidemiology, clinical presentation, management, and prognosis of this rare cause of DVT. A total of 42 studies reporting on 56 cases were included in the review. The mean age of the patients at the presentation of their first DVT episode is 23.6 years, 83.9% of patients were males, conservative management with anticoagulation was used in 68% of the reported cases, and thrombolysis was used in 32% of the cases. Only 10.7% of patients presented with PE potentially justified by the abnormal anatomy of the deep veins which makes the propagation of thrombi into the pulmonary arteries less possible. Comparing the long-term outcomes of the two treatment groups; 42.3% of the patients treated conservatively vs 15.4% of the patients treated with thrombolysis developed chronic symptoms (residual heaviness, pain, swelling, and cramping). 11.5% of patients who received conservative treatment developed post-thrombotic syndrome. None of the patients treated with thrombolysis developed post-thrombotic syndrome. There were no procedure-related complications and thrombolysis was well tolerated by the entirety of the thrombolysis treatment group. Recurrence of DVT occurred in 13% of the patients treated conservatively and in 7.7% of patients treated with thrombolysis. Thrombus removal by means of thrombolysis is the recommended treatment and can offer excellent short and long-term results. Anticoagulation with NOACs may be prescribed for life to prevent recurrence or for at least 6 months and then reconsidered following further evaluation of patients' bleeding risk. It may be of value to organise an international registry for such patients. Guidelines issued by the relevant scientific societies will then be able to make a clear recommendation about the management of such patients.

Iatrogenic partial diversion of inferior vena cava to left atrium after surgical closure of atrial septal defect

BACKGROUND

Atrial septal defects (ASDs) are one of the most common congenital cardiac abnormalities. Repair of these defects is a quite secure and routine operation. The most common complications were postoperative atrial arrhythmias, sinus arrhythmia, and atrioventricular (AV) blocks requiring pacemaker implantation, mediastinal bleeding, and transient ischemic attacks (TIAs) or strokes. Iatrogenic diversion of the inferior vena cava (IVC) to the left atrium (LA) during surgical closure of an ASD is a very rare complication.

CASE REPORT

We reported a patient who had a history of cardiac surgery in another center at the age of seven and was introduced to our clinic with complaints of dyspnea and cyanosis of extremities on exertion. She underwent surgery in our center with diagnosis of iatrogenic diversion of IVC to LA.

CONCLUSION

The most common mechanism suggested is a large eustachian valve being mistaken for the inferior rim of the ASD.

Surgical resection and graft replacement for primary inferior vena cava leiomyosarcoma: a multicenter experience

OBJECTIVE

Primary leiomyosarcoma of the inferior vena cava (IVC) is best managed with surgical resection when technically feasible. However, consensus is lacking regarding the best choice of conduit and reconstruction technique. The aim of the present multicenter study was to perform a comprehensive assessment through the VLFDC (Vascular Low Frequency Disease Consortium) to determine the most effective method for caval reconstruction after resection of primary leiomyosarcoma of the IVC.

METHODS

A multicenter, standardized database review of patients who had undergone surgical resection and reconstruction of the IVC for primary leiomyosarcoma from 2007 to 2017 was performed. The demographics, periprocedural details, and postoperative outcomes were analyzed.

RESULTS

A total of 92 patients (60 women and 32 men), with a mean age of 60.1 years (range, 30-88 years) were treated. Metastatic disease was present in 22%. The tumor location was below the renal veins in 49 (53%), between the renal and hepatic veins in 52 (57%), and above the hepatic veins in 13 patients (14%). The conduits used for reconstruction included ringed polytetrafluoroethylene (PTFE; n = 80), nonringed PTFE (n = 1), Dacron (n = 1), autogenous vein (n = 1), bovine pericardium (n = 4), and cryopreserved tissue (n = 5). Complete R0 resection was accomplished in 73 patients (79%). In-hospital mortality was 2%, with a median length of stay of 8 days. The primary patency of PTFE reconstructed IVCs was 97% and 92% at 1 and 5 years, respectively, compared with 73% at 1 and 5 years for the non-PTFE reconstructed IVCs. The overall 1-, 3-, and 5-year survival for the entire cohort were 94%, 86%, and 65%, respectively CONCLUSIONS: The findings from our multi-institutional study have demonstrated that complete en bloc resection of IVC leiomyosarcoma with vascular surgical reconstruction in selected patients results in low perioperative mortality and is associated with excellent long-term patency. A ringed PTFE graft was the most commonly used conduit for caval reconstruction, yielding excellent long-term primary patency.

The Arrhythmic Substrate for Atrial Fibrillation in Patients with Mitral Regurgitation

Objective

Patients with severe mitral regurgitation commonly develop atrial fibrillation. The precise mechanisms of this relationship remain unknown. The objective of this study was to apply noninvasive electrocardiographic imaging of the atria during sinus rhythm to identify changes in atrial electrophysiology that may contribute to development of atrial fibrillation in patients with severe mitral regurgitation referred for mitral valve surgery.

Methods

Twenty subjects (9 atrial fibrillation and mitral regurgitation, 11 mitral regurgitation alone) underwent electrocardiographic imaging. Biatrial electrophysiology was imaged with activation maps in sinus rhythm. The reconstructed unipolar electrograms were analyzed for voltage amplitude, number of deflections and conduction heterogeneity. In subjects with mitral regurgitation, left atrial biopsies were obtained at the time of surgery. Results: Subjects with history of atrial fibrillation demonstrated prolonged left atrial conduction times (110±25 ms vs. mitral regurgitation alone (85±21), p=0.025); right atrial conduction times were unaffected. Variable patterns of conduction slowing were imaged in the left atria of most subjects, but those with prior history of atrial fibrillation had more complex patterns of conduction slowing or unidirectional block. The presence of atrial fibrillation was not associated with the extent of fibrosis in atrial biopsies.

Conclusions

Detailed changes in sinus rhythm atrial electrophysiology can be imaged noninvasively and can be used to assess the impact and evolution of atrial fibrillation on atrial conduction properties in patients with mitral regurgitation. If replicated in larger studies, electrocardiographic imaging may identify patients with mitral regurgitation at risk for atrial fibrillation and could be used to guide treatment strategies.

Isolated inferior vena cava aneurysm: a case report

We report a rare case of inferior vena cava (IVC) aneurysm in a 22-year old Afghan-Iranian male patient. CT scan illustrated a saccular aneurysm of IVC originating from right side of the IVC below the renal veins (a saccular type 3 IVC aneurysm). We planned open resection and repair of the aneurysm. The patient had well recovery after the operation and his follow-up did not reveal any morbidity. IVC aneurysm is a rare clinical entity. Its diagnosis necessitates precise clinic suspicion and the management is based on anatomical location and associated anomalies.

Intra-cardiac Embolism of a Large Bone Cement Material after Percutaneous Vertebroplasty Removed through a Combination of an Endovascular Procedure and an Inferior Vena Cava Exploration: a Case Report

Percutaneous vertebroplasty (PVP) is a minimally invasive surgical treatment for patients with osteoporotic vertebral compression fracture (OVCF) and can rapidly alleviate pain, improve mobility, and stabilize the vertebrae. However, it has the potential to cause complications such as cement embolism. A 55-year-old female presented with pain in the lumbar region as a chief complaint. PVP was performed after diagnosis of acute OVCFs at L4 and L5. No abnormal symptoms were reported after surgery, but a large cement embolism was observed in her right atrium and ventricle. After discussion in a multi-disciplinary team, the large cement embolism was successfully removed by a combination of endovascular procedure and an inferior vena cava exploration. Surgeons must consider the possibility of intra-cardiac cement embolism after PVP. A hybrid approach of an endovascular procedure and a vascular surgery may be a reasonable treatment option to minimize the surgical procedure in cases of a large intra-cardiac cement embolism.

Usefulness of inferior vena cava ultrasonography in outpatients with chronic heart failure

BACKGROUND

Inferior vena cava (IVC) ultrasonography has been used for the diagnosis and prognosis of acute heart failure (HF). Its usefulness in chronic HF is less known.

HYPOTHESIS

IVC ultrasonography is a useful tool in the care of patients with chronic HF.

METHODS

For this prospective cohort study, 95 patients with chronic HF were included consecutively as they attended scheduled medical visits. Ultrasound was done with a 5-MHz convex probe device, calculating IVC collapse index (IVCCI). Follow-up time was 1 year. Outcome events were worsening HF, hospital admission for HF, HF mortality, and all-cause mortality.

RESULTS

Worsening HF occurred in 70.9% of patients with IVCCI <30% and 39.1% of patients with IVCCI >50%, with a hazard ratio (HR) of 2.8 (95% CI: 1.3-6.2) adjusted by multivariable analysis. Regarding hospitalization, 45.3% of patients with IVCCI <30% required admission, compared with 5.9% of patients with IVCCI >50%; the adjusted HR was 13.9 (95% CI: 1.7-113.0). Mortality was higher in the IVCCI <30% group, with 25.7% all-cause mortality and 18.6% HF mortality, whereas in the IVCCI >50% group these values were 13% and 4.7%, respectively. However, these differences did not reach statistical significance. ROC analysis was performed and the AUC for IVCCI was not higher than that for NTproBNP for any of the outcomes studied.

CONCLUSIONS

IVC ultrasonography is a useful tool in follow-up of patients with chronic HF, allowing identification of patients at high risk of worsening and hospitalization. However, its usefulness is not higher than that of NTproBNP.

Measurement of Central Venous Pressure Using Ultrasound in Emergency Department

Background:

In order to assessment of intravascular fluid measurement of central venous pressure (CVP) is used via central venous catheterization (CVC). This procedure is highly invasive and may cause serious complications such as pneumothorax, infection, hematoma and etc. It is so valuable procedure if we can uses a less invasive or noninvasive procedure to assess patients intravascular fluid in critical positions.

Objectives:

In this study, the ultrasound was used to measure the central venous pressure (CVP).

Patients and Methods:

In this study, patients with Central venous catheterization were selected using simple random sampling. The largest diameter of longitudinal, transverse views and the cross-section of inferior vena cava (IVC) and internal jugular vein (IJV) were measured using the ultrasound in the bedside of the patients. Central venous pressure was measured using routine methods. Correlations between variables were analyzed using SPSS and linear regression.

Results:

Twenty patients with the mean age of 60.3 were studied. The main reason for cardiac catheterization was shock. There are no relationship between anterior posterior diameter of inferior vena cava and CVP of patients (P = 0.257). The longest diameter of IVC in ultrasonographic transverse view had significant association with CVP of patients (P = 0.045) but in patients with BMI > 25 it was not significant. Cross section of internal jugular vein had significant association with CVP of patients (P = 0.003). Longitudinal diameter of internal jugular vein had no significant association with CVP of patients (P = 0.052), but transverse diameter of internal jugular generally had significant association with CVP of patients (P = 0.003). Cross section of internal jugular had significant association with CVP (P = 0.001).

Conclusions:

Noninvasive assessment of the patient hydration condition using the ultrasound is a simple and practicable measure in emergency. With regard to the considerations, it is possible to estimate CVP via diameter measurement and cross-section of the central veins.

Inferior Vena Cava and Hemodynamic Congestion

BACKGROUND

Among the indices able to replace invasive central venous pressure (CVP) measurement for patients with acute decompensated heart failure (ADHF) the diameters of the inferior vena cava (IVC) and their respiratory fluctuations, so-called IVC collapsibility index (IVCCI), measured by echocardiography, have recently gained ground as a quite reliable proxy of CVP.

OBJECTIVES

The aims of our study were to compare three different ways of evaluating cardiac overload by using the IVC diameters and/or respiratory fluctuations and by calculating the inter-method agreement.

PATIENTS AND METHODS

Medical records of patients hospitalized for right or bi-ventricular acute decompensated heart failure from January to December 2013 were retrospectively evaluated. The predictive significance of the IVC expiratory diameter and IVC collapsibility index (IVCCI) was analyzed using three different methods, namely a) the criteria for the indirect estimate of right atrial pressure by Rudski et al. (J Am Soc Echocardiogr. 2010); b) the categorization into three IVCCI classes by Stawicki et al. (J Am Coll Surg. 2009); and c) the subdivision based on the value of the maximum IVC diameter by Pellicori et al. (JACC Cardiovasc Imaging. 2013).

RESULTS

Among forty-seven enrolled patients, those classified as affected by persistent congestion were 22 (46.8%) using Rudski's criteria, or 16 (34%) using Stawicki's criteria, or 13 (27.6%) using Pellicori's criteria. The inter-rater agreement was rather poor by comparing Rudski's criteria with those of Stawicki (Cohen's kappa = 0.369; 95% CI 0.197 to 0.54), as well as by comparing Rudski's criteria with those of Pellicori (Cohen's kappa = 0.299; 95% CI 0.135 to 0.462). Further, a substantially unsatisfactory concordance was also found for Stawicki's criteria compared to those of Pellicori (Cohen's kappa= 0.468; 95% CI 0.187 to 0.75).

CONCLUSIONS

The abovementioned IVC ultrasonographic criteria for hemodynamic congestion appear clearly inconsistent. Alternatively, a sequential or simultaneous combination of clinical scores of congestion, IVC ultrasonographic indices, and circulating levels of natriuretic peptides could be warranted.

Clinical course and predictive factors for complication of inferior vena cava filters

RATIONALE

The use of inferior vena cava (IVC) filters is associated with various complications. We aimed to elucidate the clinical course and predictive factors for complications of IVC filters, especially IVC penetration

METHODS

A retrospective observational study was performed in 45 adult patients with retrievable IVC filters and follow-up computed tomography (CT) between January 2003 and December 2012. Primary outcomes were the prevalence and predictive factors of IVC penetration. Secondary outcome was other complications of IVC filters.

RESULTS

IVC penetration following filter placement occurred in 87.6% of patients, and 57.8% of those involved significant penetration. Embedding of filter tips, suggestive of lateral tilting, was observed in 51.1%. Both Vertebral body erosions and aortic penetrations were seen in 4.4%, but they were asymptomatic. Longer indwelling duration of the IVC filter was significantly associated with a higher grade of IVC penetration, and the risk of significant IVC penetration increased in patients with the filter indwelling time of more than 20 days and an IVC diameter of less than 24.2mm.

CONCLUSIONS

In patients with a retrievable IVC filter, IVC penetration on CT was common, and significant IVC penetration was associated with a longer indwelling time of the IVC filter and a lesser IVC diameter.

Successful Thrombolysis of Occluded Inferior Vena Cava Filter with IVC Syndrome

Thrombosis of Inferior Vena Cava (IVC) following filter insertion can occur in up to 30% of the cases. The optimal management of such cases is unknown. We describe a simple and less expensive method of achieving successful recanalization of the IVC in a 40 year old hypertensive man who developed recurrent pulmonary embolism after his orthopedic treatment. An IVC filter was inserted, which developed extensive thrombosis of the whole IVC and venous system of the lower limbs. Catheter directed thrombolysis using a multiple side-hole multipurpose catheter and balloon angioplasty was carried out in order to "crush and lyse" the IVC thrombi.