What complications can occur in patients with pre-existing cardiovascular disease or those on anticoagulant therapy undergoing femoral artery catheterization?

Complications of Femoral Artery Catheterization

Femoral artery catheterization carries an overall vascular complication rate of 2-6%, with the most common complications being access site bleeding, hematoma formation, pseudoaneurysm, arteriovenous fistula, arterial thrombosis, retroperitoneal hemorrhage, and arterial dissection or occlusion. 1, 2

Major Vascular Complications

Bleeding and Hematoma

• Access site hematoma occurs in approximately 10% of patients and represents the most frequent complication 3
• Active bleeding at the puncture site occurs in 2.4% of cases 3
• Retroperitoneal hemorrhage should be suspected when patients develop unexplained hypotension, bradycardia or tachycardia following high vascular puncture, particularly with decreased hemoglobin 2
• Conservative management suffices for hemodynamically stable patients, but unstable patients or those with expanding hematomas require early vascular surgical or interventional consultation 2

Pseudoaneurysm Formation

• Femoral pseudoaneurysm develops in 0.8-2.2% after diagnostic procedures and up to 4.7% after interventional procedures 4, 5
• Pseudoaneurysms form when the arterial puncture site fails to seal, allowing arterial blood to ooze into surrounding tissues and create a pulsatile hematoma 4
• Diagnosis is confirmed by Doppler ultrasound showing swirling color flow in a mass separate from the artery and characteristic "to-and-fro" waveform in the pseudoaneurysm neck 4
• Ultrasound-guided compression repair has replaced surgical repair as first-line treatment, though it carries a 3.6% complication rate and high recurrence in anticoagulated patients 4
• Percutaneous thrombin injection (average dose 192 IU) has gained popularity with consistently high success rates, though theoretical risk of IgE-mediated allergic reaction to bovine thrombin exists 4

Arterial Thrombosis

• Femoral artery thrombosis occurs in 3.6% of all cases, with rates reaching 39% after transarterial balloon dilation procedures 1, 6
• Clinical manifestations range from silent vessel occlusions to severe limb ischemia, with consequences including threatened limb viability, leg-length discrepancies, muscle wasting, claudication, and loss of arterial access for future interventions 1
• Long-term surveillance reveals even higher rates: 33% arterial occlusion detected by duplex scanning 5-14 years post-procedure, with 8% developing leg growth retardation 1
• If pulse remains absent 4 hours post-catheterization, continue heparin therapy (50 U/kg bolus, then 20 U/kg/hour infusion) for 24-48 hours 6
• 71% of patients improve with heparinization alone without requiring thrombolysis 6
• If pulse remains absent after 24-48 hours of heparinization AND systolic blood pressure is <67% of the contralateral leg, initiate thrombolytic therapy 6

Venous Complications

• Venous thrombosis at the catheterization site is well-documented, with >30% of children and adolescents presenting with access problems at subsequent catheterizations due to occluded or stenosed vessels 1
• Iliac vein or inferior vena cava occlusion occurs in 4% of patients <6 months of age after single femoral vein catheterization 1
• Most femoral venous thrombosis is clinically silent, but lacking venous access can eliminate heart transplantation as an option since reliable venous access is required for future surveillance biopsies 1

Other Vascular Complications

• Arteriovenous fistula formation occurs when both artery and vein are punctured 1
• Arterial dissection and/or occlusion can result from improper technique or unsuitable puncture sites 1

High-Risk Patient Factors

The strongest multivariate predictors of vascular complications include: 1, 2

• Age ≥70 years
• Female sex (if not corrected for body surface area)
• Body surface area ≤1.6 m² or body mass index ≥28 kg/m²
• Renal failure or creatinine ≥2 mg/dL
• Peripheral arterial disease
• Emergent procedures
• Periprocedural use of glycoprotein IIb/IIIa inhibitors

Additional high-risk factors include: 1, 5, 3

• History of CABG, congestive heart failure, bleeding disorders (hemophilia, thrombocytopenia, disseminated intravascular coagulation)
• Stroke, diabetes, chronic obstructive pulmonary disease, liver failure, immunosuppression
• Hypertension (OR 1.52)
• Coronary artery disease (OR 1.21 to 11.1)
• Higher lesion complexity and multilesion interventions
• Use of intra-aortic balloon pump
• Preprocedural thienopyridines (OR 5.65 for preprocedural antithrombotics, OR 4.88 for intraprocedural agents)
• Intraprocedural clopidogrel (OR 2.98)
• Postprocedural heparin (OR 29.4)

Technical Factors Increasing Complications

• Improper puncture site location is critical: punctures "too low" (below the common femoral artery bifurcation into profunda femoris and superficial femoral artery) or "too high" (above the superior ramus of the pubis, rendering the site noncompressible) significantly increase complications 1
• Larger catheter diameter (≥7F) increases risk (OR 2.82) 5
• High procedural volume (≥18 cases per day in a particular room) increases risk (OR 2.39), likely reflecting operator fatigue 5
• Operator experience and meticulous technique cannot be overemphasized 1

Protective Factors

Factors associated with decreased complication risk include: 3

• Use of vascular closure devices (OR 0.263)
• Male gender (OR 0.421)
• Prior ipsilateral catheterization (OR 0.033)

Critical Monitoring Requirements

Post-procedure assessment must include: 6

• Checking pedal pulses bilaterally
• Comparing systolic Doppler blood pressure between legs—systolic blood pressure <67% of contralateral leg indicates significant arterial compromise requiring immediate intervention 6
• Continuous monitoring until femoral sheath removal to detect vasovagal responses with symptomatic bradycardia 6
• Assessment for expanding hematoma that may require surgical evacuation 6

High-risk patients (those with procedural complications or significant left main coronary artery stenosis ≥50%) require continuous electrocardiographic monitoring for ≥24 hours or until complication resolved 6

Prevention Strategies

• Ultrasound-guided access should be considered to reduce complications, particularly in high-risk patients 2
• Femoral angiogram verification of arterial puncture site is standard practice 1
• Procedural anticoagulation (100 U/kg UFH bolus) with activated clotting time maintained >200 seconds during procedure reduces thrombotic complications 6
• Careful management of anticoagulation and antiplatelet therapy reduces bleeding complications 2
• Radial artery access is preferred over femoral access when feasible, as it decreases access-related bleeding and complications 1

Common Pitfalls

• Failing to recognize retroperitoneal hemorrhage in patients with unexplained hypotension and high puncture sites 2
• Inadequate post-procedure monitoring in high-risk patients receiving intensive anticoagulation 3
• Premature ambulation before adequate hemostasis is achieved 6
• Overlooking clinically silent arterial or venous thrombosis that may compromise future vascular access 1
• Using closure devices inappropriately in low-risk patients (male gender, prior ipsilateral catheterization) where they may not be warranted 3