Treatment of Posterior Communicating Artery (PComm) Aneurysms
For ruptured PComm aneurysms amenable to both techniques, endovascular coiling is the preferred treatment to improve 1-year functional outcomes, while surgical clipping should be strongly considered for unruptured PComm aneurysms in patients under 40 years old due to superior long-term durability. 1
Ruptured PComm Aneurysms
Primary Treatment Approach
Endovascular coiling is recommended over surgical clipping for good-grade ruptured PComm aneurysms that are technically suitable for both modalities, as this improves 1-year functional outcomes (Class I, Level A evidence). 1
Treatment should be performed as early as feasible (ideally within 24-72 hours) to reduce the 20-30% rebleeding risk in the first month. 1
Both neurosurgical and endovascular specialists must evaluate the aneurysm together to determine optimal treatment strategy (Class I, Level C evidence). 1
Specific Clinical Scenarios Favoring Surgery
Patients over 65 years with ruptured PComm aneurysms may benefit more from coiling based on ISAT subgroup analysis, though this advantage disappears in patients over 70 years old. 1
Surgical clipping receives increased consideration when there is a large intraparenchymal hematoma (>50 mL) requiring emergency evacuation, as this provides both clot removal and aneurysm securing simultaneously with significantly lower mortality (27% vs 80%). 1
New third nerve palsy ipsilateral to a PComm aneurysm indicates aneurysm growth and warrants urgent treatment; surgical clipping achieves significantly higher rates of complete oculomotor nerve palsy resolution (55% vs 32%, OR 2.6) compared to endovascular treatment. 1, 2
Unruptured PComm Aneurysms
Treatment Indications by Age and Size
Patients under 60 years with aneurysms >5 mm should be offered treatment unless significant contraindications exist, as PComm location carries higher rupture risk than other anterior circulation sites. 1
Microsurgical clipping is the preferred first choice for young, healthy patients (particularly those under 40 years) with small anterior circulation aneurysms, as surgical repair is "at least an order of magnitude more durable than coiling" despite similar short-term stroke and death risks. 1
For patients 60-70 years old with unruptured PComm aneurysms, treatment is still strongly advocated given the higher rupture risk of this location and low associated treatment morbidity, though the decision becomes less clear in those over 70. 1
Large aneurysms >10 mm should be treated in all healthy patients under 70 years, with indications less compelling in older individuals. 1
Technical Considerations
Aneurysms with narrow necks (diameter <5 mm) and favorable dome-to-neck ratios (<0.5) are ideal candidates for endovascular coiling with better outcomes in terms of complications and complete occlusion rates. 1
Wide-neck aneurysms not amenable to primary coiling or clipping can be reasonably treated with stent-assisted coiling or flow diverters (Class IIa, Level C-LD evidence). 1
Avoid stents or flow diverters in acute ruptured saccular aneurysms when primary coiling or clipping is feasible, as dual antiplatelet therapy requirements increase hemorrhagic complications, particularly ventriculostomy-related bleeding (Class III: Harm, Level B-NR evidence). 1
Critical Management Pitfalls
Symptomatic unruptured PComm aneurysms carry greater surgical risk than truly incidental aneurysms, particularly when presenting with cerebral ischemia or mass effect symptoms. 1
Complete obliteration should be the goal whenever possible (Class I, Level B evidence), as incomplete treatment increases rebleeding risk and necessitates long-term angiographic surveillance. 1
Elderly patients (>70 years) show no clear benefit from coiling over clipping in randomized data, contrary to common practice patterns; treatment decisions should be based on aneurysm characteristics rather than age alone in this population. 1
Cognitive deficits occur in 12% of patients at 1 year after treatment of unruptured aneurysms and must be factored into treatment decisions, particularly for asymptomatic lesions. 1
Follow-Up Requirements
Delayed follow-up vascular imaging is mandatory after both coiling and clipping, with timing and modality individualized based on completeness of initial treatment (Class I, Level B evidence). 1
Retreatment should be strongly considered for clinically significant or growing remnants, using either repeat coiling or microsurgical clipping. 1
Catheter angiography remains the preferred follow-up modality after coil embolization despite its <0.1% permanent complication risk, though noninvasive screening may identify patients requiring intervention. 1