Venous
Procedure Guide
Acute Deep Venous Thrombosis
Acute (<14d) iliofemoral DVT in non-elderly patient and/or good pre-DVT functional status, low bleeding risk, and moderate to severe symptoms. Not isolated tibial, popliteal, or femoral DVT.
If subacute (2-4 wks), some recommend waiting and managing with ambulation and compression stockings
Emergent: phlegmasia alba dolens -> phlegmasia cerulea dolens
Urgent: IVC, renal or hepatic vein thrombosis
Chronic Deep Venous Thrombosis/Occlusion
Chronic thrombus (>4 wks) with recurrent DVTs, severe PTS, and/or severe limitations on ADLs
Patients with iliofemoral DVT develop ulceration/skin changes in 34%, venous claudication in 43%, venous reflux in 69%
50% DVT patients develop PTS, often within 2 yrs, 5-10% will be severe PTS
78% of patients with recurrent DVT develop PTS
Moderate/Severe arm, leg, chest, or face swelling, refractory ascites, stridor, cerebral venous HTN, AVF dysfunction (prolonged bleeding, progressive dilation, access thrombosis)
NOT hemodynamic significance (>50% stenosis, pressure gradient >5-10 mmHg) alone as intervention may induce more rapid progression
Absolute
Acute stroke (including TIA), head trauma, or neurologic surgery within 3 months
Active internal hemorrhage or DIC
Severe pulmonary HTN
Relative
Major trauma, CPR, surgery, or birth within 10 days
Intracranial tumor
BP >180/110
GI bleed within 3 months
Pregnancy
Right to left shunt
Infected thrombus
Severe liver or kidney dysfunction
Hemorrhage diabetic retinopathy
Bleeding disorder
Hyperkalemia (>6 mEq/L)
Allergy to thrombotic agent or contrast
Thoracic outlet and Paget-Schroetter syndrome - Surgery shoulder be performed either first or soon after thrombolysis/thrombectomy
Acute DVT: SIR position statement
Therapeutic anticoagulation should be started as soon as possible. LMWH may be superior to UFH in terms of shorter time to therapeutic levels, lower recurrent VTE, and trend towards reduced mortality.
Limited data for pregnancy, children, and older adults. For pregnancy, risks of CDT likely outweigh the benefit. Some limited data supporting use in certain peds populations.
CDT/PCDT suggested over MT for patients with phlegmasia
For other acute iliofemoral DVT, ideal pt for consideration of CDT/PCDT is nonelderly, good pre-DVT functional status, moderate to severe symptoms, and low bleeding risk. Overall likely to have significant short term symptom/QoL benefit with mixed data regarding long term benefit (see trials below). Can also trial anticoagulation only for 3-7 days and intervene if little improvement in symptoms.
ATTRACT trial: RCT 692 pt with acute DVT above the popliteal -> PCDT did not prevent PTS over conventional therapy @ 2 yrs. However, subanalyses have suggested CDT may be more beneficial for pts with higher baseline Villatta scores. Also cost effective long term in reducing costs associated with PTS.
CaVenT trial: RCT 209 pts with acute DVT extending above the mid thigh -> showed CDT (rt-PA, thrombectomy devices not used) reduced absolute risk of PTS 28% @ 5 yrs but no difference in QoL
CAVA trial: RCT 184 pts with acute iliofemoral DVT -> US-assisted CDT (EKOS) had no effect on PTS or QoL @ 1 yr. Secondary analysis did show a significant reduction in PTS but not QoL.
BERNUTIFUL trial: RCT of US-assisted DCT vs conventional CDT -> Ekosonic MACH 4 showed no difference in thrombus removal, safety, or 1-yr PTS
RCT of MT: Suction thrombectomy had higher venous patency and fewer symptoms @ 1 yr
CLOUT registry: ClotTriever thrombectomy for acute to chronic clot, 99% single session, median EBL 40 mL, complete or near complete thrombus removal >90%, device related SAEs 0.2% without reports of valve or vessel damage, rethrombosis 5.0% in 30 days and 8.4% in 6 months, moderate to severe PTS at 2 yrs in 7.4%, no PTS in 76.7%
RCT of stenting after acute iliofemoral DVT with residual >50% stenosis -> superior 1 yr patency and improved venous QoL. Systematic review estimates early stent thrombosis in 6.5% and 1 yr patency of 87%
Systematic review: No difference in >50% clot lysis between CDT and MT/PCDT but higher major bleeds with CDT (6% v. 1%)
Chronic venous insufficiency and Post thrombotic syndrome
Limited data, mostly single center and case series but promising.
CLOUT registry described above included patients with chronic thrombotic obstructions demonstrating benefit
ACCESS-PTS trial: chronic DVT with Villalta >=8 treated with LMWH, venoplasty, and EKOS thrombolysis >= 12 hrs. Mean Villalta scores reduced from 15.5 to 9.7 at 30 days and 7.8 at 1 year
STEVECO trial: RCT of best medical therapy vs stenting for PTS and NIVL. Showed improvement in VEINES QoL and symptoms at 12 mo but investigators set a very high definition of improvement (QoL difference of at least 14 points), which was not met.
Central vein stenosis/occlusion: 80-100% technical success, ~40% will need reintervention within 5 yrs
Primary and secondary patency up to 10 yrs of 35-90% and 72-94%; better with bare metal stents, perhaps better still with drug-eluting balloons
SVC syndrome: 77-91% primary patency (1 yr), 85% secondary (17 mo). If malignant, 6 month survival <50%.
Iliofemoral/IVC: 50-85% primary patency, 90-100% secondary patency
HD-related: 76% primary patency (6 mo)
Budd-Chiari: 92% primary patency (23 mo)
Systematic review for central thoracic occlusions: 6 and 12 mo primary patency for PTA 50.9 and 36.7%; for stenting 69.7 and 47.9%; serious adverse events PTA and stenting 3.8 and 8.1%; access loss PTA and stenting 14.7 (5.2-41.6) and 30.9% (16.4-58.1); procedure related AEs PTA and stenting 10.8 and 3.9%
12 mo patency all similar (~80%) in venous stent trials for VICI, Zilver Vena, Venovo, and Abre
Acute management of phlegmasia: bolus 5000 IU heparin, start drip at 100U/hr, elevate extremity
Robust clinical history: chronicity symptoms, provoked vs unprovoked VTE, anticoagulation history, hypercoagulability work up, prior interventions, and signs of venous insufficiency
Villalta score for post-thrombotic syndrome severity
Risk factors: malignancy, trauma, prolonged immobilization, obesity, pregnancy, advanced age, smoking, hyperviscosity (polycythemia vera, blast crisis), Factor V Leiden, Prothrombin G20210A, High FVIII, Protein C & S deficiencies, Antithrombin (III) deficiency, Methylenetetrahydrofolate reductase (MTHFR) polymorphism (no VTE risk unless elevated homocysteine), Homocysteinemia
Imaging: often start with venous duplex US for screening prior to CTV or MRV for further characterization.
Need adequate CTV, not just portal venous phase, e.g., 125 mL contrast at 3 mL/s with 50 mL saline chase, 130 sec acquisition delay
Most continue antiplatelet agents if already taking. Also good to start aspirin 1 day prior if time.
Lovenox and UFH should be continued and used as anticoagulation during the procedure. DOAC are either continued or partially held, e.g., stopped the day before.
For chronic venous insufficiency, need to document trial of conservative therapy, e.g., compression garments (at least 20-30 mmHg), venous ulcer care (or medications pentoxifylline), and anticoagulation +/- venoactive supplements such as diosmin, horse chestnut extract
GA often required for chronic recanalization
Obtain access, e.g., internal jugular, common femoral, greater saphenous, popliteal, posterior tibial
Sometimes single access is sufficient, e.g., popliteal access for iliofemoral DVT thrombolysis. However access on either side of the clot is often helpful for chronic obstructions or for caval clot to place a protection device.
(Optional) Place protection device in IVC to prevent pulmonary emboli during the procedure. Can use devices like the Inari Protrieve or an IVC filter with hook still engaged to resheath at the end of the case or leave in place if substantial residual clot.
Advance sheath with size pending planned devices to be used.
Venogram in multiple projections to characterize clot, obstruction, and collaterals.
NOTE: the native vein in chronic occlusions can be subtle and may only appear as a thin string or tapering at the level of the obtruction (the “string sign”)
Cross the clot/obstruction
For acute clot, this can often be done with a hydrophilic wire alone (e.g. glidewire) followed by a catheter (e.g. Kumpe) to exchange for a stiffer working wire (e.g. Amplatz) to advance devices for thrombectomy or the lysis catheter. Alternatively, the more expensive glidewire advantage can help cross the clot and serve as a working wire.
For chronic clot/obstructions, sometimes a hydrophilic wire and Kumpe is successful but often requires a braided or hydrophilic crossing catheter such as a Quick-cross (Spectranetics), Navicross (Terumo), Rubicon (Boston Scientific), or CXI (Cook). Often works to spin a hydrophilic wire quickly to “drill” through occlusion and inch catheter behind as making progress.
Advanced options for refractory occlusions:
Sharp recanalization with TJ liver bx metal stiffener and/or backend of wire or Colapinto, Rosch-Uchida, or 65 cm chiba needle using snare on opposite end at target; good for short, straight lesions
RF wire (e.g. Powerwire, Baylis Medical)
True Path CTO Device (Boston Scientific), diamond coated tip that spins at 13K RPM
Important to confirm intraluminal course prior to plasty or stenting
Must be careful not to damage adjacent structures, e.g, right common iliac, right renal artery, distal ureter (can place ureter stent or PCNU for better visualization and avoidance.
Systemic heparinization (70 U/kg) with ACT goal >240 prior to intervention.
Debated whether to hold off anticoagulation until the obstruction is crossed or give throughout.
Recheck ACT every 30-60 minutes to maintain >240 with additional heparin boluses as needed.
Remaining procedure often consists of thrombolysis, thrombectomy, venoplasty, and/or stenting pending chronicity of the clot/obsutrction and anatomy. Generally, thromboysis and thrombectomy work better for more acute to subacute clot due to higher fibrin to collagen ratio though newer devices can remove some organized/chronic clot. Venoplasty is better from chronic obstructions and macerating small residual acute clot. Stenting is often reserved for underlying anatomic obstructions, e.g., May-Thurner syndrome or to maintain patency after recanalization of chronic obstructions.
Thrombolysis via infusion catheter (e.g. Unifuse, Cregg-McNamara, EKOSonic)
Can be left to infuse overnight with tPA at 0.5-1 mg/hr/catheter for 20 mg or 0.01 mg/kg/hr
Can also be used in combination with thrombectomy to “soften” or break up clot where the clot is laced with 5-25 mg tPA prior to thrombectomy. Some wait 20-40 minutes to allow the tPA time to dissolve clot.
New Bashir catheter - pharmacomechanial CDL via 7F nitinol infusion basket
Thrombectomy, multiple different devices, examples below
AngioJet (Boston Scientific) - Rheolytic thrombectomy via 3-8 Fr catheter. Advantage is ability to maintain wire access across occlusion and pulse spray thrombolytic agent through same device. Disadvantage is tendency to cause bradycardia, worse closer to the heart which is why it has a black box warning for use in PE.
Example technique: Pulse spray lytic, wait 20-30 min, then aspirate. Monitor for bradycardia working in 10 sec intervals allowing heart rate to normalize. Can have atropine available as well. Safe and effective in PEARL DVT study.
Newer ClotHunter feature can improve thrombus removal in exchange for losing wire access work similar to other devices.
Aspirex (BD) - Mechanical and suction thrombectomy via 6-8 Fr catheters. Cheaper and low tech than other device while still being effective.
AngioVac - Requires perfusionist with V-V-ECMO, 26 Fr funnel-shaped tip inflow for aspiration, 16-20 Fr outflow. Likely best for large thrombus burden in areas such as caval or RA thrombus or saddle PE.
Cleaner (Argon) - Rotational device to break up clot. Most often used for dialysis access interventions but some will inflate a balloon downstream of the clot, lace with tPA/heparin, and then macerate with the Cleaner followed by aspiration for DVT.
Lightning Indigo and Flash systems (Penumbra) - Computer-assisted aspiration to help reduce blood loss, range of smaller, lower profile catheter sizes (6-12 Fr)
JETi (Abbot) - Hydrodynamic aspiration thrombectomy (lower risk of AKI and bradycardia). Lower profile 6-8 Fr catheters.
ClotTreiver (Inari) - Nitinol mesh basket captures clot and pulls into 13 Fr sheath with self-expanding nitinol mesh funnel. Great results in even a single pass but there are reports of damage to vessels with rethrombosis in femoral and popliteal veins.
FlowTreiver (Inari) - Aspiration via 16-24 Fr catheter, nitinol discs can be used to pull clot into aspiration catheter. Can then given aspirated blood back.
Venoplasty
Rough general sizes to keep in mind but patients vary:
Lower extremity: IVC to 18-20 mm, common iliac 14-16 mm, external iliac/CFV 12-14 mm, femoral 10-12 mm, popliteal ~8 mm, tibial veins 6-8 mm
Upper extremity: subclavian to 10-14 mm; brachiocephalic to 12-16 mm; superior vena cava to 14-20 mm
Significant stenosis definition varies but commonly considered >50% luminal narrowing or pressure gradient =>3 mmHg
Some perform prolonged venoplasty 1-10 min if waist is present
Residual stenosis: repeat angioplasty w/ 2 mm larger balloon
Elastic recoil: repeat angioplasty or place stent
Vessel rupture: protamine -> low-pressure balloon tamponade -> stent graft
Stenting
Indicated for stenoses refractory to venoplasty alone, e.g., external compression due to malignancy or iliac vein compression (May Thurner) syndrome. VIDIO trial data suggests stenting iliofemoral stenosis if >54% post-thrombotic or >61% nonthrombotic on IVUS.
Multiple studies suggest adequate inflow is the single most important factor for stent patency. Some say the inflow vessel, e.g., femoral needs to be at least 8-10 mm in diameter. Be sure access is low enough to treat entire diseased segment. Okay to stent below the inguinal ligament to lesser trochanter but should generally not stent into the femoral vein or jail off the profunda.
Sizing - make sure the patient is well hydrated. Some use the contralateral or normal equivalent vessel. Others use the diameter of the inflow vessel, oversize 2 mm, and do not plasty beyond this size. Root mean-square (RMS) may be more accurate than calculating an average diameter given the often ellipsoid shape of veins.
Bilateral common iliacs - some suggest kissing stents into an IVC stent is better than kissing stents alone to prevent Poisson effect (candy wrappering) inhibiting outflow.
Bilateral brachiocephalics - additional option is Y-stenting where one stent is deployed from the brachiocephalic into the SVC and the second extends through the interstices of the first. The Y-lumen is then opened with plasty. The avoids over dilating the SVC and risk of cardiac tamponade and requires more malleable stents (e.g. SMART stents rather than Venovo).
Multidisciplinary international consensus recommends IVUS to characterize thrombectomy/thrombolysis end point or plan/guide venoplasty and stenting
VIDIO study: IVUS identified significant (>50% stenosis) not detected by venography in 26% and changed management in 57%
Of note, some feel IVUS is oversensitive/overused. It should be complementary to fluoro given that you’re ultimately deploying your stent under fluoro guidance
Some recommend starting therapeutic Lovenox (1 mg/kg) intra-operatively at the end of the procedure.
Thrombolysis can cause hemoglobinuria, hyperkalemia, and AKI
Bradyarrhythmia with AngioJet
Major bleeding with CDT/PCDT: 1-5%, no reported death or ICH in contemporary RCTs, Cochrane review including older limited studies does show increased risk of major bleeding (6.7% v. 2.2%) and intracranial bleeding
Peri-procedural PE is rare (<1%)
Access site hematoma
Crossing chronic occlusions: hemothorax, mediastinal hematoma, pericardial tamponade, arterial injury, stent migration, in-stent stenosis
Often requires ICU monitoring if lysis overnight.
Encourage early ambulation. Some use SCDs for inpatients and compression stockings for outpatients even while anticoagulated.
Anticoagulation and antiplatelets
Thrombotic lesion - LMWH for 1 mo followed by transition to a DOAC (or warfarin) for 6-12 months total plus ASA or Plavix. Often 81 mg ASA is continued for life if recanalization of chronic occlusion with stenting
Non-thrombotic lesion (NIVL) - ASA/Plavix for 3 months
Hematology consultation for long term management of anticoagulation and hypercoagulable work up if appropriate. Brief review of their literature is below.
Highest risk of rethrombosis is within the first year but increases to ~36% overall over 10 years.
Patients with major transient factors provoking the DVT such as trauma or surgery have a low risk (<3% per year). Patients with idiopathic thrombosis, transient factors such as pregnancy, or non-malignant persistent factors have an intermediate risk (3-8% per year). Patients with a major persistent factor such as active malignancy have the highest risk (>8% per year). So ESC guidelines recommend considering extended anticoagulation for intermediate and high risk patients. Likely not needed for low risk patients.
Reduced dose DOAC (2.5 mg apixaban BID or 10 mg rivaroxaban OD) after 6 months of therapeutic AC should be considered for intermediate risk patients without cancer per EINSTEIN EXT, EINSTEIN CHOICE, and AMPLIFY-EXT trials.
Wound care if venous ulcers are present
If stent was placed, follow up CTV in 3 months and 1 year. Some will monitor with US and Villalta scores starting 1 month post-op.