Overview

Definition: Ilio-caval thrombectomy with stent reconstruction is a complex endovascular or open surgical procedure aimed at removing extensive thrombus from the iliac and inferior vena cava (IVC) veins, often followed by angioplasty and stenting to restore venous patency and prevent recurrent thrombosis.
Epidemiology: Ilio-caval DVT affects a significant proportion of patients with extensive lower extremity DVT, with estimates suggesting it occurs in 10-20% of all DVT cases, often associated with high morbidity including post-thrombotic syndrome and pulmonary embolism.
Clinical Significance: This intervention is crucial for selected patients with acute ilio-caval DVT to prevent severe post-thrombotic syndrome (PTS), reduce the risk of chronic venous insufficiency, improve quality of life, and potentially decrease the incidence of recurrent VTE and pulmonary embolism.

Indications

Indications For Procedure:
-Acute ilio-caval DVT with symptoms of extensive venous obstruction (e.g., phlegmasia cerulea dolens, severe limb swelling, rapid onset of pain)
-Presence of contraindications to anticoagulation alone
-Selected patients with phlegmasia alba dolens and significant venous claudication or limb swelling
-Contraindication or failure of anticoagulation alone
-Acute extensive proximal DVT with high risk of PTS development.
Patient Selection Criteria:
-Patient must be medically fit for a major procedure
-Absence of significant contraindications to anticoagulation post-procedure
-Presence of extensive thrombus burden amenable to thrombectomy
-Symptom duration typically less than 14-21 days for optimal results
-Absence of severe underlying comorbidities that would preclude benefit.
Contraindications:
-Active bleeding or significant bleeding risk
-Severe sepsis
-Irreversible limb ischemia
-Uncorrectable coagulopathy
-Known IVC filter migration or severe IVC abnormalities preventing intervention
-Patients with limited life expectancy
-Inability to tolerate anticoagulation.

Preoperative Preparation

Imaging And Assessment:
-Comprehensive venous duplex ultrasound to assess thrombus extent, mobility, and flow
-CT venography or MR venography for detailed anatomical mapping of the ilio-caval system, thrombus burden, and venous anatomy
-Assess for IVC anomalies or filters
-Echocardiography to rule out right heart strain if PE is suspected.
Anticoagulation Strategy:
-Initiation of therapeutic anticoagulation (e.g., unfractionated heparin drip or low molecular weight heparin) prior to intervention to prevent further thrombus propagation
-Planning for post-procedure anticoagulation regimen.
Multidisciplinary Discussion:
-Discussion involving vascular surgeons, interventional radiologists, hematologists, and anesthesiologists to formulate the optimal treatment strategy
-Assessment of patient comorbidities and anesthetic risk.

Procedure Steps

Access And Catheterization:
-Percutaneous venous access, typically through femoral or popliteal veins, using ultrasound guidance
-Advancement of sheaths into the IVC and iliac veins
-Contrast venography to confirm thrombus burden and map anatomy
-Use of specialized thrombectomy catheters (e.g., AngioJet, Trellis) for mechanical thrombus removal.
Thrombus Removal:
-Mechanical thrombectomy using aspiration or rheolytic thrombectomy devices
-Pharmacomechanical thrombolysis with catheter-directed infusion of thrombolytic agents (e.g., alteplase, urokinase) into the thrombus under fluoroscopic guidance
-Careful assessment of thrombus lysis and residual stenosis.
Angioplasty And Stenting:
-Balloon angioplasty of residual stenoses in the iliac veins and IVC
-Placement of self-expanding venous stents (e.g., Wallstent, Viabahn) across the stenotic segments and potentially extending into the IVC to ensure adequate luminal gain and prevent acute re-occlusion
-IVUS or IVL may be used to assess lesion severity and stent expansion.
Completion Venography:
-Completion venography to assess the patency of the treated segments, the position of the stents, and absence of flow-limiting residual stenosis or dissection
-Ensure adequate inflow and outflow of venous return.

Postoperative Care

Monitoring And Anticoagulation:
-Continuous monitoring of vital signs, limb perfusion, and pain
-Intensive anticoagulation with a target INR of 2.0-3.0 for vitamin K antagonists, or continuous heparin infusion initially, transitioning to a DOAC or LMWH
-Regular duplex ultrasound surveillance to assess stent patency and venous flow.
Ambulation And Physiotherapy:
-Early ambulation and physiotherapy to prevent complications like pneumonia and immobility-related issues
-Graduated compression stockings are essential to manage post-thrombotic syndrome and support venous return
-Avoid prolonged sitting or standing.
Medications:
-Long-term anticoagulation is mandatory
-Duration varies based on etiology and risk factors, often lifelong for extensive ilio-caval DVT
-Pain management as needed
-Avoidance of certain medications that can interfere with anticoagulation or increase bleeding risk.

Complications

Early Complications:
-Bleeding at access sites
-Hematoma formation
-Compartment syndrome in the limb
-Pulmonary embolism during or after procedure
-Stent migration or malapposition
-Acute stent thrombosis
-Access site vascular injury
-Allergic reaction to contrast media
-Venous rupture or perforation.
Late Complications:
-Chronic post-thrombotic syndrome (PTS) characterized by pain, swelling, skin changes, and venous ulcers
-Stent restenosis or thrombosis
-Chronic venous hypertension
-Recurrent DVT
-Lymphedema
-Device-related complications.
Prevention Strategies:
-Meticulous procedural technique
-Judicious use of thrombolytic agents
-Accurate stent sizing and placement
-Aggressive anticoagulation post-procedure
-Prompt recognition and management of complications
-Patient education on lifestyle modifications and adherence to therapy.

Prognosis

Factors Affecting Prognosis:
-Extent and duration of thrombus at presentation
-Presence of underlying thrombophilia
-Adherence to anticoagulation and compression therapy
-Quality of revascularization and stent patency
-Absence of significant post-thrombotic syndrome symptoms
-Patient's overall health status.
Outcomes:
-Successful recanalization and stent patency can significantly reduce the risk of severe PTS and improve limb function and quality of life
-Long-term patency rates for ilio-caval stents vary, with studies reporting 70-90% patency at 1-2 years with optimal management, but restenosis remains a concern.
Follow Up:
-Regular clinical assessment and duplex ultrasound monitoring are crucial, typically for the first 1-2 years post-procedure, then annually or as indicated
-Lifelong anticoagulation and compression therapy are generally recommended
-Patient education on symptom monitoring for recurrence or PTS progression.

Key Points

Exam Focus:
-Indications for thrombectomy vs
-anticoagulation alone in ilio-caval DVT
-Mechanical vs
-pharmacomechanical thrombolysis
-Role of angioplasty and stenting in managing residual stenosis
-Importance of post-procedure anticoagulation and compression
-Risk factors for PTS and strategies to prevent it.
Clinical Pearls:
-Consider IVUS for accurate assessment of stenosis and stent deployment in the ilio-caval system
-Stent choice is critical
-venous stents are designed for low-pressure systems
-Meticulous attention to anticoagulation and compression is paramount for long-term success
-Early recognition of stent thrombosis is vital.
Common Mistakes:
-Inadequate thrombus removal leading to residual stenosis
-Inappropriate stent selection or undersizing
-Insufficient anticoagulation post-procedure
-Lack of patient compliance with compression stockings and follow-up
-Failure to identify and manage underlying thrombophilia.