Subdural Fluid Collection After the Clipping of Unruptured Intracranial Aneurysms: Its Clinical Course and Significance

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.

Subdural Hygroma After Management of Ruptured Intracranial Aneurysms: Incidence, Associated Factors, Clinical Course, and Management Options

OBJECTIVE

To evaluate the incidence, associated factors, clinical course, and management options of subdural hygroma in patients treated for aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

From January 2013 until June 2022, 336 consecutive patients with aSAH underwent treatment in our center. No one patient was excluded from the study cohort. Computed tomography (CT) examinations were performed at admission, immediately after surgery and on the first postoperative day, and subsequently in case of any neurologic deterioration or, at least, once per week until discharge from the hospital. Thereafter, CT examinations were at the discretion of specialists in the rehabilitation facility, referring physicians, or neurosurgeons at the outpatient clinic.

RESULTS

The length of radiologic follow-up starting from CT at admission ranged from 1 to 3286 days (mean, 673 ± 895 days; median, 150 days). Subdural hygromas developed in 84 patients (25%). An average interval until this imaging finding from the initial CT examination was 25 ± 55 days (median, 8 days; range, 0-362 days). Evaluation in the multivariate model showed that patient age ≥72 years (P < 0.0001), cerebrospinal fluid (CSF) shunting (P < 0.0001), and microsurgical clipping of ruptured intracranial aneurysm (RIA; P < 0.0001) are independently associated with the development of subdural hygroma. In 54 of 84 cases (64%), subdural hygromas required observation only. Increase of the lesion size with (5 cases) or without (10 cases) appearance of midline shift was associated with patient age <72 years (P = 0.0398), decompressive craniotomy (P = 0.0192), and CSF shunting (P = 0.0009), whereas evaluation of these factors in the multivariate model confirmed independent association of only CSF shunting (P = 0.0003). Active management of subdural hygromas included adjustment of the shunt programmable valve opening pressure, cranioplasty, external subdural drainage, or their combination. Overall, during follow-up (mean, 531 ± 824 days; median, 119 days; range, 2-3285 days) after the start of observation or applied treatment, subdural hygromas showed either decrease (50 cases) or stabilization (34 cases) of their sizes, and no one lesion showed progression again.

CONCLUSIONS

The clinical course of subdural hygromas in patients treated for aSAH is generally favorable, but occasionally these lesions show progressive enlargement with or without the appearance of midline shift, which requires active management.

Subdural hygroma and hemorrhagic conversion after microsurgical clipping for unruptured intracranial aneurysm

BACKGROUND

Chronic subdural hematoma (cSDH) is a unique hemorrhagic complication associated with microsurgical clipping. We aimed to investigate the risk factors of subdural hygroma (SDG) formation and its hemorrhagic conversion to cSDH.

METHODS

We reviewed the medical records of 229 patients who underwent microsurgical clipping for unruptured intracranial aneurysms (UIA) from 2016 to 2019. Risk factors for SDG and cSDH formation were analyzed.

RESULTS

Male sex, age ≥ 60 years, higher degree of arachnoid dissection, severe brain atrophy, and a large volume of subdural fluid collection (SFC) before discharge were independent risk factors for SDG formation. The risk factors for hemorrhagic conversion from SDG were continuous use or early resumption of antiplatelet drugs (odds ratio (OR): 15.367, 95% CI: 1.172-201.402) and a larger volume of SFC before discharge (OR: 0.932, 95% CI: 0.886-0.980). In the early resumption group, antiplatelet drug was resumed at a mean duration of 7.48 days postoperatively, and hemorrhagic conversion was detected earlier than that in the late resumption or no-use groups (4.09 vs. 7.18 weeks, P = 0.046). Following the receiver operating characteristic analysis, the SFC cutoff volume for hemorrhagic conversion was determined to be 23.55 mL.

CONCLUSION

These findings can assist clinicians in identifying patients at a high risk of SDG and cSDH formation. Antiplatelet resumption and its timing should be determined with consideration of the risk of cSDH formation as well as individual medical conditions.

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.