Device Directed Therapy for Pulmonary Embolus Therapy

Commercial Catheter Platforms for Large Pulmonary Embolism

Device (Manufacturer)	Mechanism / Category	Access size (Fr)	FDA PE Indication	Key Pros	Key Cons
FlowTriever® (Inari Medical)	Large-bore mechanical aspiration & nitinol disks	16 – 24 F	Yes	Removes bulk clot rapidly; often no lytics needed. Robust FLASH / FLAME data with low 30-day mortality and RV/LV improvement.	Very large sheath → bleeding / venotomy repair risk; blood loss (may need re-transfusion); limited reach into distal branches.
Indigo® Lightning 12 (Penumbra)	Computer-assisted vacuum aspiration	12 F	Yes	Smaller bore than FlowTriever; “Lightning” algorithm auto-stops suction when only blood detected → less blood loss; highly trackable catheter.	Requires 12 F venotomy; may need multiple passes; less real-world outcome data.
AlphaVac™ F1885 (AngioDynamics)	Directional aspiration with steerable funnel	18 F	Yes (2024)	Large funnel minimises clogging and limits blood loss; APEX-AV study showed marked RV/LV reduction.	Largest access of any PE device; limited post-market data; high capital cost.
AngioJet™ ZelanteDVT (Boston Scientific)	Rheolytic jet thrombectomy	8 F	Off-label	Widely available; can combine with “power-pulse” lytic; rapid debulking possible.	Black-box warning for bradyarrhythmia / hemolysis & AKI risk; off-label for PE; smaller lumen than other mechanical systems.
EKOSonic™ (Boston Scientific)	Ultrasound-assisted CDT (US-CDT)	5 – 6 F dual	Yes	Allows 50–70 % lower tPA dose vs standard CDT; RCTs (ULTIMA, SEATTLE II, OPTALYSE) show rapid RV recovery & low bleeding.	Requires 2–6 h thrombolytic infusion & ICU monitoring; no mechanical extraction for very large clot burden; higher disposable cost.
BASHIR™ (Thrombolex)	Expandable basket pharmacomechanical CDT	7 – 8 F	Yes	Basket re-establishes flow then bathes clot with low-dose lytic; smaller sheath; early BEC-PE / RESCUE data encouraging.	Lytic still required (bleeding risk); limited large-scale evidence; deployment learning curve.
Cragg-McNamara™ (Medtronic)	Multi-side-hole infusion catheter (standard CDT)	4 – 5 F	Off-label	Inexpensive; widely stocked; easy bilateral placement; minimal access size.	Requires 12–24 h lytic infusion → higher bleeding risk; passive lysis with slower RV recovery.
Uni-Fuse® (AngioDynamics)	Pressure-response-outlet infusion catheter	4 – 5 F	Off-label	Even drug dispersion; low cost; familiar workflow.	Same prolonged-infusion bleeding concerns; no mechanical component.
Fountain® (Merit Medical)	Gradient-hole infusion catheter	4 – 5 F	Off-label	Laser-drilled spiral holes give uniform dispersion (5–50 cm lengths); useful in distal branches or hybrid setups.	Needs prolonged lytic infusion; minimal data in massive clot; non-mechanical.

¹ “FDA PE indication” refers to explicit 510(k) clearance naming pulmonary embolism. Devices marked “Off-label” are cleared for peripheral use but commonly employed in PE at operator discretion.

How to use this chart

• Match patient & clot profile — Large-bore thrombectomy (FlowTriever, AlphaVac, Lightning 12) excels when a big, central clot must come out fast and bleeding risk is high.
• Balance bleeding vs access risk — Ultrasound- or basket-assisted CDT (EKOS, Bashir) lowers tPA dose but still requires several hours and systemic anticoagulation; standard infusion catheters are simplest but use full-dose lytic.
• Mind the sheath size — A 24 F FlowTriever or 18 F AlphaVac may not be tolerated in small femoral veins or severe RV failure; 5 F infusion catheters can be placed via a single 12 F dual-lumen sheath for bilateral therapy.
• Confirm indications & experience — Some devices (e.g. AngioJet, standard infusion catheters) are widely used in PE but technically off-label; follow institutional policy and your PERT algorithm.

Situations Where Catheter-Based PE Devices Outperform
Systemic Thrombolysis or Anticoagulation Alone

Clinical scenario	Why device therapy is preferred	Why thrombolytics / heparin fall short
Absolute / major relative contraindication to systemic lysis • Recent intracranial hemorrhage or neurosurgery • Intracranial mass / AVM • Major non-CNS surgery or trauma < 2 weeks • Active or high-risk bleeding diathesis	Mechanical or low-/no-lytic catheters debulk clot while avoiding systemic fibrinolytic exposure.	Systemic tPA forbidden or carries prohibitive ICH/GI-bleed risk; heparin alone cannot reverse shock or severe RV strain.
Massive (high-risk) PE with impending or ongoing hemodynamic collapse	Large-bore aspiration/thrombectomy provides immediate after-load relief and can be performed rapidly in the cath or IR suite.	Systemic tPA may require 30–120 min for effect and can worsen hypotension once given; anticoagulation alone is too slow.
Failure of systemic thrombolysis • Persistent shock / RV dysfunction ≥ 2 h after full-dose tPA	Serves as rescue strategy—mechanically removes residual clot, often restoring MAP and oxygenation within minutes.	Repeat lysis markedly increases ICH risk; further observation with heparin alone risks cardiac arrest.
Intermediate-high risk PE (RV/LV ≥ 1.0 plus elevated troponin) • Early clinical deterioration or escalating vasopressor/O2 needs • Moderate bleeding risk (e.g., age > 75, recent GI bleed)	Randomized and registry data (PEERLESS, FLASH) show rapid RV recovery, less ICU utilization, and fewer clinical deteriorations versus catheter-directed thrombolysis or AC alone.	Full-dose systemic tPA not guideline-endorsed in this group (bleeding vs. benefit); anticoagulation alone may not prevent progression.
Pregnancy / early postpartum with massive or intermediate-high risk PE	Mechanical thrombectomy or low-dose catheter lysis minimizes maternal & fetal hemorrhage risk while achieving reperfusion.	Systemic lytics carry up to 20 % maternal bleeding and fetal-loss risk; surgery poses greater anesthesia/uterine perfusion hazards; heparin alone insufficient when shock or severe RV strain present.
Very large proximal (saddle/main) clot with severe RV strain or refractory hypoxemia, but bleeding risk high	Registry (FLASH) shows > 20 % drop in mPAP and rapid RV/LV ratio normalization without systemic lytics.	Systemic tPA dose needed to clear massive burden raises major bleed risk; anticoagulation alone rarely reverses RV failure fast enough.

*Device therapy = mechanical thrombectomy, ultrasound-assisted catheter-directed thrombolysis (US-CDT), or low-dose pharmacomechanical CDT, selected per institutional protocol and operator expertise.*

How to apply this table

• Risk-stratify first — Use ESC/AHA classification, RV imaging, and biomarkers to identify high- and intermediate-high–risk patients.
• Screen for bleeding risk — Absolute or major relative thrombolytic contraindications immediately tilt the scale toward mechanical or low-dose catheter therapies.
• Engage your PERT early — Rapid multidisciplinary decision-making speeds access to the cath/IR suite and mechanical circulatory support if needed.
• Match device to anatomy & urgency — Large-bore aspiration (FlowTriever, AlphaVac) for central clot and shock; US-CDT (EKOS) or basket-assisted (BASHIR) when partial lytic use is acceptable.