Efficacy of Arachnoid-Plasty on Chronic Subdural Hematoma Following Surgical Clipping of Unruptured Intracranial Aneurysms

Natural course of chronic subdural hematoma following surgical clipping of unruptured intracranial aneurysm by pterional approach

OBJECTIVE

Chronic subdural hematoma (CSDH) is a neurological complication following clipping surgery. However, the natural course and ideal approach for the treatment of clipping-related-CSDH (CR-CSDH) have not been clearly established. We aimed to investigate the course of CR-CSDH using chronological radiological findings.

METHODS

We performed a retrospective analysis of 28 (3.8%) patients who developed CSDH among 736 patients who underwent surgical clipping using pterional approach for unruptured aneurysms at our institution between December 2010 and December 2018. Patients underwent follow-up CT scan 6-8 weeks after clipping surgery and decision to pursue surgical intervention rests upon the patient's symptom based on the Markwalder's grading scale (MGS) and numeric rating scale (NRS).

RESULTS

Of the 28 patients, 3 patients (10.7%) underwent surgery, while 25 (89.2%) showed spontaneous resolution of CR-CSDH. Eighteen patients (64.2%) had mild headache with MGS of 0-1. The mean maximum hematoma volume was 41.9±30.9 ml (5.8-135 ml), and 26 patients (92.8%) had homogeneous hematoma. The mean time to hematoma resolution was 126.7±52.9 days (46-228 days). Comparing group of CR-CSDH volume ≥43 ml or a midline shift ≥5 mm, the difference in presence of linear low-density area (p=0.002) and age (p=0.026) between the conservative and operative groups were found to be statistically significant.

CONCLUSIONS

Most CR-CSDH cases spontaneously resolved within 4 months. Therefore, we suggest that close observation should be performed if patient's symptoms are mild and special radiologic findings are present, despite its relatively large volume and midline shifting.

Arachnoid Plasty to Prevent and Reduce Chronic Subdural Hematoma after Clipping Surgery for Unruptured Intracranial Aneurysm : A Meta-Analysis

Objective

Recent studies have reported that arachnoid plasty (ARP) using gelatin sponges with fibrin glue reduced the occurrence of chronic subdural hematoma (CSDH) following clipping surgery for unruptured intracranial aneurysm (UIA). This meta-analysis was conducted to collate further evidence for the efficacy of ARP in preventing postoperative CSDH.

Methods

Data of patients who underwent clipping surgery were extracted from PubMed, EMBASE, and Cochrane Central Register of Controlled Trials by two independent reviewers. A random effects model was used to investigate the efficacy of ARP by using odd ratios (ORs) and 95% confidence intervals (CIs). A meta-regression analysis for male sex was additionally preformed.

Results

Data from six studies with 1715 patients were consecutively included. Meta-analysis revealed that ARP was significantly associated with lower rates of CSDH development after surgical clipping for UIA (ARP group vs. control group : 3.2% vs. 7.2%; OR, 0.40; 95% CI, 0.18–0.93; I² =44.3%; p=0.110). Meta-regression analysis did not highlight any modifying effect of the male sex on postoperative CSDH development (p=0.951).

Conclusion

This meta-analysis indicated that ARP reduced the incidence rates of CSDH following clipping surgery for UIA. If feasible, ARP would be implemented as an additional surgical technique to prevent postoperative CSDH development during surgical clipping of UIA.

Extensive postoperative subdural fluid volume affects the onset of chronic subdural hematoma after unruptured aneurysmal clipping surgery

OBJECTIVE

To evaluate risk factors associated with chronic subdural hematoma (CSDH) onset after clipping surgery for unruptured intracranial aneurysm, and determine whether intraoperative conventional arachnoid-plasty (ARP) can suppress the CSDH onset by reducing subdural fluid volume.

PATIENTS AND METHODS

We retrospectively evaluated 217 patients who underwent surgical clipping at our institution from 2012 to 2018. Risk and predictive factors for symptomatic CSDH development including clinical characteristics, postoperative subdural fluid volume, Hounsfield unit (HU) value of subdural fluid density evaluated by CT and the effect of conventional ARP were compared between CSDH and non-CSDH groups.

RESULTS

Of 217 patients who underwent surgical clipping for anterior circulation aneurysm, 209 were included in this study. Among whom, postoperative CSDH, required burr irrigation, occurred in 12 (5.7%). Mean age was significantly higher in the CSDH group (70 ± 8 years) than in the non-CSDH group (64 ± 11 years, p = 0.03). Subdural fluid volumes on postoperative day (POD)1, POD8 and POD30 were significantly larger in the CSDH group than in the non-CSDH group (38.4 ± 33.5 cm³, 54.8 ± 36.3 cm³, 77.2 ± 36.1 cm³ vs 10.0 ± 7.7 cm³, 16.1 ± 12.8 cm³, 14.0 ± 17.5 cm³, p < 0.001, respectively). However, intraoperative conventional ARP did not reduce postoperative subdural fluid volume nor suppress onset of CSDH. Multivariate logistic regression analysis revealed extensive subdural fluid volume as the only risk factor independently associated with CSDH development.

CONCLUSIONS

In this study, postoperative large subdural fluid volume represented an independent risk factor associated with the incidence of CSDH after unruptured aneurysmal clipping. Reducing subdural fluid volume strategy could suppress the onset of CSDH after surgery.

Potential Risks and Limited Indications of the Supraorbital Keyhole Approach for Clipping Internal Carotid Artery Aneurysms

Background

Internal carotid artery (ICA) aneurysm may be a good target for supraorbital keyhole clipping. We discuss the surgical indications and risks of keyhole clipping for ICA aneurysms based on long-term clinical and radiologic results.

Methods

This was a retrospective analysis of 51 patients (aged 35–75 years, mean 62 years) with ICA aneurysms (mean 5.8 ± 1.8 mm) who underwent clipping via the supraorbital keyhole approach between 2005 and 2017. Neurologic and cognitive functions were examined by several methods, including the modified Rankin Scale and Mini-Mental Status Examination. The state of clipping was assessed 1 year and then every few years after the operation.

Results

Complete clipping was confirmed in 45 patients (88.2%), dog-ear remnants behind the clip persisted in 4 patients, and wrapping was performed in 2 patients. Mean duration of postoperative hospitalization was 3.4 ± 6.9 days. The mean clinical follow-up period was 6.6 ± 3.2 years. The overall mortality was 0, and overall morbidity (modified Rankin Scale score ≥2 or Mini-Mental Status Examination <24) was 3.9%. Completely clipped aneurysms did not show any recurrence during the mean follow-up period of 6.3 ± 3.1 years, but the 2 (3.9%) aneurysms with neck remnants showed regrowth.

Conclusions

The risk of neck remnant behind the clip blade is a drawback of supraorbital keyhole clipping. The surgical indication requires preoperative simulation and careful checking of the clip blade state is essential.