Diagnostic performance of lower extremity Doppler ultrasound in detecting iliocaval obstruction

Inferior and Superior Vena Cava Reconstruction

Obstructions of the superior and inferior vena cava are prevalent etiologies of deep venous obstruction, presenting a spectrum of clinical manifestations ranging from life-threatening conditions to asymptomatic states. The etiological diversity inherent to these central venous obstructions necessitates a subtle approach to their diagnosis and management. This discrepancy in clinical presentations emphasizes the importance of a differentiated diagnostic and therapeutic strategy, tailored to the specific form of vena cava obstruction encountered. This article aims to delineate the various manifestations of vena cava obstruction and encourages specific diagnostic and treatment pathways.

Noninvasive and invasive imaging of lower-extremity acute and chronic venous thrombotic disease

The spectrum of venous thromboembolic (VTE) disease encompasses both acute deep venous thrombosis (DVT) and chronic postthrombotic changes (CPC). A large percentage of acute DVT patients experience recurrent VTE despite adequate anticoagulation, and may progress to CPC. Further, the role of iliocaval venous obstruction (ICVO) in lower-extremity VTE has been increasingly recognized in recent years. Imaging continues to play an important role in both acute and chronic venous disease. Venous duplex ultrasound remains the gold standard for diagnosing acute VTE. However, imaging of CPC is more complex and may involve computed tomography, magnetic resonance, contrast-enhanced ultrasound, or intravascular ultrasound. In this narrative review, we aim to discuss the full spectrum of venous disease imaging for both acute and chronic venous thrombotic disease.

Preprocedural imaging modalities in patients undergoing iliocaval venous recanalization and stent placement

PURPOSE

To determine the diagnostic accuracy of preinterventional imaging modalities in patients being evaluated for iliocaval venous recanalization and stent placement.

METHODS

Consecutive patients with iliocaval postthrombotic obstructions or nonthrombotic iliac vein lesions (NIVL), who were scheduled for recanalization, underwent duplex ultrasound (DUS), magnetic resonance venography (MRV), multiplanar venography (MPV), and intravascular ultrasound (IVUS). The diagnostic accuracies of DUS, MRV, and MPV were analyzed using IVUS as reference.

RESULTS

A total of 216 limbs in 108 patients (80 patients with postthrombotic obstructions, 28 patients with NIVL) were examined. In patients with postthrombotic obstructions, the diagnostic sensitivities for the detection of lesions of the common femoral vein were 81% (95% CI 71-89%) for DUS, 76% (95% CI 65-85%) for MRV, and 86% (95% CI 76-93%) for MPV. The sensitivities for detecting lesions of the iliac veins were 96% (95% CI 89-99%) for DUS, 99% (95% CI 92-100%) for MRV, and 100% (95% CI 94-100%) for MPV. Regarding the inferior vena cava, the sensitivities were 44% (95% CI 24-65%) for DUS, 52% (95% CI 31-73%) for MRV, and 70% (95% CI 47-86%) for MPV. The sensitivities for detecting NIVL were 58% (95% CI 34-79%) for DUS, 90% (95% CI 68-97%) for MRV, and 95% (95% CI 73-99%) for MPV.

CONCLUSION

In patients scheduled for recanalization of iliocaval postthrombotic obstructions, the sensitivities of DUS, MRV, and MPV were similar. In patients with suspected inferior vena cava involvement and in patients with NIVL, additional imaging with MR or conventional venography is required.

Strategy to avoid vascular injuries in revision total hip arthroplasty with intrapelvic implants

Aims

Our objective was describing an algorithm to identify and prevent vascular injury in patients with intrapelvic components.

Methods

Patients were defined as at risk to vascular injuries when components or cement migrated 5 mm or more beyond the ilioischial line in any of the pelvic incidences (anteroposterior and Judet view). In those patients, a serial investigation was initiated by a CT angiography, followed by a vascular surgeon evaluation. The investigation proceeded if necessary. The main goal was to assure a safe tissue plane between the hardware and the vessels.

Results

In ten at-risk patients undergoing revision hip arthroplasty and submitted to our algorithm, six were recognized as being high risk to vascular injury during surgery. In those six high-risk patients, a preventive preoperative stent was implanted before the orthopaedic procedure. Four patients needed a second reinforcing stent to protect and to maintain the vessel anatomy deformed by the intrapelvic implants.

Conclusion

The evaluation algorithm was useful to avoid blood vessels injury during revision total hip arthroplasty in high-risk patients. Cite this article: Bone Jt Open 2022;3(11):859–866.

Iliocaval Reconstruction: Review of Technique, Challenges, and Outcomes

Iliocaval thrombosis is a major source of morbidity for patients, with a range of clinical presentations, including recurrent lower extremity deep venous thrombosis and postthrombotic syndrome. Endovascular reconstruction of chronic iliocaval occlusion has been demonstrated to be a technically feasible procedure that provides long-lasting symptom relief in combination with antithrombotic therapy and close clinical monitoring. Herein, we describe the etiologies of iliocaval thrombosis, patient assessment, patient management prior to and after intervention, procedural techniques, and patient outcomes.

Treatment of Non-thrombotic Iliac Vein Stenosis: Where is the Evidence?

Non-thrombotic iliac vein lesions (NIVLs) refer to iliac vein lumen stenosis, usually secondary to extrinsic compression, without associated thrombosis. Clinical presentation varies; patients may be asymptomatic, have symptoms of lower extremity venous hypertension, or in women, may be associated with chronic pelvic pain. Given the significant variability in symptomatology, thorough history and physical examination are mandatory in excluding other causes of symptoms. Non-invasive imaging, such as venous duplex/insufficiency ultrasound examinations, and axial imaging aid in the diagnosis of a NIVL in the appropriate clinical context. Catheter venography and intravascular ultrasound remain the primary modalities for definitive diagnosis, treatment planning, and ultimately placement of self-expanding venous stents to resolve the causative iliofemoral venous obstruction. In appropriately selected patients, stent placement can lead to marked improvements in symptoms, heal stasis ulceration when present, and improve disease-specific and overall quality of life. Stents placed in patients with NIVL demonstrate high long-term primary patency. In this article, the authors discuss clinical presentation, diagnostic workup, endovascular interventions and outcomes of NIVL treatment.

Treatment of Nonthrombotic Iliac Vein Lesions

Nonthrombotic iliac vein lesions (NIVLs) most frequently result from extrinsic compression of various segments of the common or external iliac vein. Patients develop symptoms associated with chronic venous insufficiency (CVI); female patients may develop symptoms of pelvic venous disease. Given that iliac vein compression can be clinically silent, a thorough history and physical examination is mandatory to exclude other causes of a patient's symptoms. Venous duplex ultrasound, insufficiency examinations, and axial imaging are most commonly used to assess for the presence of a NIVL. Catheter venography and intravascular ultrasound (IVUS) are the mainstay for invasive assessment of NIVLs and planning prior to stent placement. IVUS in particular has become the primary modality by which NIVLs are evaluated; recent evidence has clarified the lesion threshold for stent placement, which is indicated in patients with moderate to severe symptoms. In appropriately selected patients, stent placement results in improved pain, swelling, quality of life, and, when present, healing of venous stasis ulcers. Stent patency is well preserved in the majority of cases, with a low incidence of clinically driven need for reintervention. In this article, we will discuss the clinical features, workup, endovascular management, and treatment outcomes of NIVL.

Transabdominal duplex ultrasound and intravascular ultrasound planimetry measures of common iliac vein stenosis are significantly correlated in a symptomatic population

OBJECTIVE

The objectives of the present study were to determine the validity of transabdominal duplex ultrasound (TAUS) against the reference standard of intravascular ultrasound (IVUS) examinations for the detection of iliac vein obstruction (IVO).

METHODS

We analyzed the data from patients at a private vascular laboratory who had undergone IVUS investigation with an intention to treat because of symptoms of chronic venous insufficiency and a high suspicion of IVO. These patients had also previously undergone a TAUS examination at the same location. The TAUS and IVUS planimetry measures of the left common iliac vein (CIV) were correlated. These included the TAUS-measured minimum and maximum diameter and the percentage of stenosis with the IVUS-measured minimum and maximum diameter and area and the percentage of stenosis.

RESULTS

The TAUS and IVUS data from 47 patients (83% female; age, 49.3 ± 17.3 years; 64% obese) were included in the analyses. We found 89% agreement between the TAUS and IVUS findings regarding the identification of left CIV stenosis of ≥50%. The TAUS data had a positive predictive value of 95.5%. The TAUS measures of the minimum diameter and percentage of stenosis correlated significantly with the IVUS measures of the minimum diameter, minimum area, and cross-sectional area of the percentage of stenosis. The strongest correlations were between the TAUS-measured minimum diameter and IVUS-measured minimum area and percentage of the area of stenosis according to the literature-derived value. The TAUS-measured vein diameter of 8 mm equated to an IVUS cross-sectional area of 94.2 mm² (53% stenosis), and an IVUS cross-sectional area of 50% of stenosis equated to a TAUS diameter of 8.56 mm.

CONCLUSIONS

The findings from the present study support the validity of TAUS evaluation as a workup diagnostic tool for the detection of IVO. Our findings also support the use of TAUS planimetry-in particular, the CIV diameter of ≤8 mm as a threshold value-to indicate clinically relevant stenosis and trigger an IVUS investigation with an intention to treat, because this correlated with a cross-sectional area stenosis of ≥50%, as determined by IVUS examination.