Percentages of Oculomotor Nerve Palsy Resolution in Coiling vs Clipping for Unruptured Posterior Communicating Artery Aneurysms
According to the meta-analysis by Zheng and Chen, surgical clipping demonstrates significantly higher rates of complete oculomotor nerve palsy (ONP) resolution at 55% compared to 32% with endovascular coiling for posterior communicating artery aneurysms. 1
Resolution Rates by Treatment Modality
- Surgical clipping achieves complete ONP resolution in 55% of cases versus 32% with endovascular coiling 1
- Any degree of ONP resolution (complete or partial) occurs in 92% of clipped cases versus 74% of coiled cases 1
- Multivariate analysis shows surgical clipping is significantly associated with ONP resolution of any degree with an odds ratio of 12.2 (95% CI, 3-49) 1
- Complete ONP resolution with clipping has an odds ratio of 7.1 (95% CI, 1.8-28) compared to coiling 1
Factors Affecting ONP Recovery
- Partial ONP at presentation is more likely to achieve complete resolution than complete ONP (OR = 4.2,95% CI 1.1-16) 2
- Time interval from onset of ONP to intervention is a significant predictor of recovery (shorter intervals lead to better outcomes) 3
- Patient age is a significant predictor of recovery (younger patients have better outcomes) 3
- Longer follow-up duration correlates with higher rates of complete nerve recovery 4
Endovascular Coiling Outcomes
- In a series of 20 patients with PCOM aneurysm-induced ONP treated with endovascular coiling:
- 45% achieved complete recovery
- 55% achieved partial recovery
- No patients failed to show improvement 5
- In another series of 37 patients treated with endovascular approaches:
- 37.8% achieved complete ONP resolution
- 51.4% achieved partial ONP resolution
- Only 10.8% showed no signs of nerve recovery 4
Surgical Clipping Outcomes
- Surgical clipping with or without additional oculomotor nerve decompression via aneurysm sac dissection shows similar outcomes 2
- The initial severity of ONP is inversely associated with the likelihood of complete resolution after surgical treatment 2
- Surgical clipping provides better long-term protection from aneurysm recurrence, which may be particularly important for younger patients 6
Treatment Considerations for Posterior Communicating Artery Aneurysms
- For patients over 65 years of age, coiling is superior to clipping for internal carotid and posterior communicating artery aneurysms 6
- For younger patients, clipping may offer advantages due to better long-term protection from rerupture 6
- The American Heart Association/American Stroke Association guidelines note that for posterior circulation aneurysms, coiling is generally preferred over clipping 7
Limitations of Current Evidence
- Most studies on ONP recovery are retrospective and have limited sample sizes 3
- There is a lack of prospective randomized trials directly comparing clipping versus coiling specifically for ONP resolution 3
- Long-term follow-up data on quality of life and cognitive outcomes after clipping versus coiling are limited 6