Introduction: Recurrence of the aneurysm after coil embolization is not infrequent and surgical treatment of previously coiled aneurysms is necessary in some patients. The best neurosurgical strategy and technique continues to be debated. We conducted a systematic review of the literature to evaluate the safety and efficacy of surgical treatment of previously coiled aneurysms.

Methods: Comprehensive review of the literature for studies on surgical treatment of previously coiled aneurysms. For each study, the following data were extracted: patient demographics, initial clinical status, location and size of aneurysms, time interval between initial/last endovascular procedure and surgery, surgical indications and microsurgical technique. We performed subgroup analyses to compare direct clipping versus coil removal and clipping versus parent vessel occlusion, early (<4 weeks post-coiling) versus late surgery and anterior versus posterior circulation.

Results: 26 studies with 466 patients and 471 intracranial aneurysms were included. Patients undergoing direct clipping had lower perioperative morbidity (5.0%, 95%CI=2.6%-7.4%) when compared to those undergoing coil removal and clipping (11.1%, 95%CI=5.3%-17.0%) or parent vessel occlusion (13.1%, 95%CI=4.6%-21.6%) (P=0.05). Patients receiving early surgery (<4 weeks post-coiling) had significantly lower rates of good neurological outcome (77.1%, 95%CI=69.3%-84.8%) when compared to those undergoing late surgery (92.1%, 95%CI=89.0%-95.2%) (P<0.01). There were higher rates of long-term neurological morbidity in posterior circulation group (23.1% versus 4.7%, P<0.01) as well as long-term neurological mortality (4.4% versus 2.8%, P<0.01).

Conclusions: Our meta-analysis demonstrated that surgical treatment is safe and effective. Our data suggest that direct clipping is superior to other surgical techniques. Late surgery was also associated with superior clinical outcomes. Surgery of recurrent posterior circulation aneurysms was associated with high rates of morbidity and mortality.

Patient Care: Our study is the first meta-analysis studying outcomes of surgical treatment of previously coiled aneurysms. Because of the large sample size, we were able to compare outcomes by aneurysm location, rupture status, type of surgery and timing of surgery and make a number of important conclusions. Other strengths of our study include the following: following an a priori established protocol, the comprehensive literature search that involves multiple databases, and the process of study selection that was performed by independent reviewers thus fulfilling the PRISMA guidelines. We acknowledge that our meta-analysis has limitations. The methodologic quality of the studies included was variable. Surgical indications, primary clinical status and outcome assessment differed across studies. Yet, the finding that all studies produced consistent results and described similar surgical experience and postoperative outcomes reassures us that these methodologic differences do not negate the validity of the meta-analysis.

Learning Objectives: Surgical Strategies and Outcomes in Patients with Previously Coiled Aneurysms

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