In active methamphetamine users, does transarterial endovascular stent‑coiling of intracranial aneurysms increase procedural risk?

Methamphetamine Use and Endovascular Stent-Coiling: Increased Procedural Risk

Active methamphetamine use significantly increases procedural risk for endovascular stent-coiling of intracranial aneurysms and is associated with worse clinical presentations, higher complication rates, and poorer outcomes compared to non-users.

Evidence for Increased Risk in Methamphetamine Users

Presentation Severity and Baseline Risk

• Methamphetamine users present with significantly higher Hunt and Hess grades (3.0 vs 2.5 in non-users, p<0.020) despite being younger (45.2 vs 55.9 years), indicating more severe hemorrhages at presentation 1
• When compared to age-matched controls, MA users have even worse Hunt and Hess grades (3.0 vs 2.0, p<0.001) and significantly lower Glasgow Outcome Scale scores (3 vs 5, p<0.001) 1
• MA users demonstrate markedly elevated mean arterial pressure at presentation (122.1 vs 109.7 mmHg, p=0.005), creating a more unstable hemodynamic environment for intervention 1

Aneurysm Characteristics in MA Users

• Methamphetamine causes rapid aneurysm growth, with documented cases showing significant enlargement in less than 2 weeks, dramatically increasing rupture risk 2
• MA-associated aneurysms have significantly higher aspect ratios (2.20 vs 1.74, p=0.02), indicating hazardous remodeling patterns that may complicate endovascular treatment 3
• Small aneurysms (<7mm) rupture at much higher rates in MA users: 36.5% of all small aneurysms and 70% of posterior circulation aneurysms <7mm present with rupture, compared to typical low-risk profiles in non-users 4

Procedural and Post-Procedural Complications

• Vasospasm rates are dramatically elevated in MA users (92.9% vs 71.1% in non-users, p=0.008), creating a hostile vascular environment for endovascular manipulation 1
• In multivariate analysis, MA use independently predicts poor outcomes (OR 3.777, p=0.018) after aneurysmal SAH treatment 1
• Ruptured aneurysms treated with stent-assisted coiling have higher complication rates (6.8% overall), with subarachnoid hemorrhage presentation being an independent predictor of procedural complications 5

Baseline Endovascular Risks Without MA Use

For context, standard procedural risks in non-MA users include 6:

• Aneurysmal perforation: 2.4%
• Ischemic complications: 8.5%
• Permanent procedural complications: 3.7%
• 30-day mortality for coiling: 2.0%
• 30-day disability: 7.4%

Critical Clinical Implications

Pre-Procedural Considerations

• Hemodynamic stabilization is paramount: Aggressive blood pressure control must be achieved before attempting endovascular intervention given the markedly elevated MAP in MA users 1
• Toxicology screening is mandatory: All patients presenting with aneurysmal SAH should undergo urine toxicology testing to identify MA use and stratify risk 1, 3
• Multidisciplinary team involvement: Given the 3.8-fold increased odds of poor outcomes, neurosurgery, interventional neuroradiology, and critical care must jointly assess whether the patient can tolerate the procedure 1

Technical Modifications

• Stent-before-coil technique is preferred: Delivering the stent before coil deployment reduces procedural complications in complex aneurysms, which is particularly relevant given the hazardous remodeling patterns in MA users 5
• Posterior circulation aneurysms warrant extreme caution: With 70% of small posterior circulation aneurysms presenting ruptured in MA users, these lesions require meticulous technique 4

Post-Procedural Monitoring

• Intensive vasospasm surveillance: The 92.9% vasospasm rate mandates aggressive monitoring and prophylaxis protocols 1
• Extended ICU monitoring: Higher Hunt and Hess grades and complication rates justify prolonged critical care observation 1
• Close angiographic follow-up: Given the dynamic vascular effects of MA and rapid aneurysm growth potential, surveillance imaging should occur at shorter intervals than standard protocols 2, 4

Common Pitfalls to Avoid

• Underestimating rupture risk in small aneurysms: Standard guidelines recommend observation for aneurysms <7mm, but this does not apply to MA users where 36.5% of small aneurysms present ruptured 4
• Assuming age-appropriate risk: MA users present 10 years younger but with worse clinical grades than older non-users, so age-based risk stratification is unreliable 1
• Proceeding without adequate blood pressure control: The significantly elevated MAP creates both technical challenges and increased rupture risk during catheter manipulation 1
• Failing to counsel on continued MA use: The dynamic temporal effects of MA on intracranial vessels mean continued use post-procedure dramatically increases rebleeding and recurrence risk 2