Subdural Fluid Collection Research Articles

The efficacy and safety of burr-hole craniotomy without continuous drainage for chronic subdural hematoma and subdural hygroma in children under 2years of age.

Various treatment modalities have been used in the management of chronic subdural hematoma and subdural hygroma (CSDH/SDHy) in children. However, few studies have examined burr-hole craniotomy without continuous drainage in such cases. Here, we retrospectively evaluated the efficacy and safety of burr-hole craniotomy without continuous drainage for CSDH/SDHy in children under 2years old. We also aimed to determine the predictors of CSDH/SDHy recurrence. We conducted a retrospective chart review of 25 children under 2years old who underwent burr-hole craniotomy without continuous drainage for CSDH/SDHy at a pediatric teaching hospital over a 10-year period. We analyzed the relationship between CSDH/SDHy recurrence and factors such as abusive head trauma, laterality of CSDH/SDHy, and subdural fluid collection type (hematoma or hygroma). CSDH/SDHy recurred in 5 of the 25 patients (20%), requiring a second operation at an average of 0.92 ± 1.12months after the initial procedure. The mean follow-up period was 25.1 ± 28.6months. There were no complications related to either operation. None of the assessed factors were statistically associated with recurrence. Burr-hole craniotomy without continuous drainage for CSDH/SDHy appears safe in children aged under 2years and results in a relatively low recurrence rate. No predictors of CSDH/SDHy recurrence were identified. Advantages of this method include avoiding external subdural drainage-related complications. However, burr-hole drainage may be more effective for CSDH, which our data suggests is more likely to recur than SDHy, providing the procedure is performed with specific efforts to reduce complications.

Symptomatic Infratentorial and Supratentorial Subdural Fluid Collection Complicating Foramen Magnum Decompression for Chiari Malformation Type I

Subdural cerebrospinal fluid collection and ventricular dilatation occur rarely after foramen magnum decompression. We report 2 cases of symptomatic subdural fluid collection after uncomplicated foramen magnum decompression for Chiari I malformation with syringomyelia. In these cases, postoperative magnetic resonance imaging showed significant shrinkage of the syrinx. The patients subsequently experienced clinical deterioration on days 9 and 13 after discharge, respectively. Repeat magnetic resonance imaging showed bilateral infratentorial subdural fluid collection extending supratentorially, passing through the tentorial notch, and with prominent midline shift. Inferior decent of the cerebellum into the decompression field was also demonstrated. Following evacuation of the subdural fluid by burr-hole and drainage for 3 days, clinical signs did not improve until symptomatic treatment with strict bed rest in the Trendelenburg position was prescribed. In such cases the arachnoid either should not be opened, or should be widely opened and expansile duraplasty performed. It is the authors’ opinion that the latter is the appropriate treatment, followed by conservative therapy including the Trendelenburg position, and restriction of ambulation and effort.

Macrocephaly in infancy: benign enlargement of the subarachnoid spaces and subdural collections.

OBJECTIVE Benign enlargement of the subarachnoid spaces (BESS) is a common finding on imaging studies indicated by macrocephaly in infancy. This finding has been associated with the presence of subdural fluid collections that are sometimes construed as suggestive of abusive head injury. The prevalence of BESS among infants with macrocephaly and the prevalence of subdural collections among infants with BESS are both poorly defined. The goal of this study was to determine the relative frequencies of BESS, hydrocephalus, and subdural collections in a large consecutive series of imaging studies performed for macrocephaly and to determine the prevalence of subdural fluid collections among patients with BESS. METHODS A text search of radiology requisitions identified studies performed for macrocephaly in patients ≤ 2 years of age. Studies of patients with hydrocephalus or acute trauma were excluded. Studies that demonstrated hydrocephalus or chronic subdural hematoma not previously recognized but responsible for macrocephaly were noted but not investigated further. The remaining studies were reviewed for the presence of incidental subdural collections and for measurement of the depth of the subarachnoid space. A 3-point scale was used to grade BESS: Grade 0, < 5 mm; Grade 1, 5-9 mm; and Grade 2, ≥ 10 mm. RESULTS After exclusions, there were 538 studies, including 7 cases of hydrocephalus (1.3%) and 1 large, bilateral chronic subdural hematoma (0.2%). There were incidental subdural collections in 21 cases (3.9%). Two hundred sixty-five studies (49.2%) exhibited Grade 1 BESS, and 46 studies (8.6%) exhibited Grade 2 BESS. The prevalence of incidental subdural collections among studies with BESS was 18 of 311 (5.8%). The presence of BESS was associated with a greater prevalence of subdural collections, and higher grades of BESS were associated with increasing prevalence of subdural collections. After controlling for imaging modality, the odds ratio of the association of BESS with subdural collections was 3.68 (95% CI 1.12-12.1, p = 0.0115). There was no association of race, sex, or insurance status with subdural collections. Patients with BESS had larger head circumference Z-scores, but there was no association of head circumference or age with subdural collections. Interrater reliability in the diagnosis and grading of BESS was only fair. CONCLUSIONS The current study confirms the association of BESS with incidental subdural collections and suggests that greater depth of the subarachnoid space is associated with increased prevalence of such collections. These observations support the theory that infants with BESS have a predisposition to subdural collections on an anatomical basis. Incidental subdural collections in the setting of BESS are not necessarily indicative of abusive head injury.

Predicting Factors of Chronic Subdural Hematoma Following Surgical Clipping in Unruptured and Ruptured Intracranial Aneurysm.

ObjectiveThe aim of this study is to analyze the differences in the incidence, predicting factors, and clinical course of chronic subdural hematoma (CSDH) following surgical clipping between unruptured (UIA) and ruptured intracranial aneurysm (RIA).MethodsWe conducted a retrospective analysis of 752 patients (UIA : 368 and RIA : 384) who underwent surgical clipping during 8 years. The incidence and predicting factors of CSDH development in the UIA and RIA were compared according to medical records and radiological data.ResultsThe incidence of postoperative CSDH was higher in the UIA (10.9%) than in the RIA (3.1%) (p=0.000). In multivariate analysis, a high Hounsfield (HF) unit (blood clots) for subdural fluid collection (SFC), persistence of SFC ≥5 mm and male sex in the UIA and A high HF unit for SFC and SFC ≥5 mm without progression to hydrocephalus in the RIA were identified as the independent predicting factors for CSDH development (p<0.05).ConclusionThere were differences in the incidence and predicting factors for CSDH following surgical clipping between UIA and RIA. Blood clots in the subdural space and persistence of SFC ≥5 mm were predicting factors in both UIA and RIA. However, progression to hydrocephalus may have in part contributed to low CSDH development in the RIA. We suggest that cleaning of blood clots in the subdural space and efforts to minimize SFC ≥5 mm at the end of surgery is helpful to prevent CSDH following aneurysmal clipping.

Spontaneous Disappearance of Arachnoid Cyst after Head Trauma.

A 4-year-old boy was referred to the pediatrician for an increased head circumference, noted to be in the 95th percentile. His neurological examination showed no focal neurological abnormality, cranial nerve deficit or papilledema. MRI of the brain (Fig. A) revealed a welldefined, nonenhancing, extra-axial mass in the right frontotemporal region, between the tabula interna and the insula. The mass is isointense to CSF on T1 (Figs. A, B) and T2 weighted images (Fig. C). This fluid collection suppresses completely with FLAIR and shows no restriction on DWI. There is scalloping of bone margins and medial displacement of cortical veins. Based on these imaging findings the diagnosis of a right frontotemporal arachnoid cyst was made. Five years later the patient experienced a painful, hard blow against a lamppost on the right side of the head. Five weeks after this head trauma a follow-up MRI of the brain was performed (Figs. D–F). Unexpectedly, the arachnoid cyst has regressed for the most part. Most likely, resorption of the cyst has occurred after the head trauma. There is a little linear collection of fluid in the subdural region, which is isointense on T1 weighted images (Fig. D), hyperintense on T2 weighted images (Fig. E) without suppression on FLAIR (Fig. F). T2* weighted images show no evidence of late subacute hemorrhage. Probably, there is little granulation tissue formation in reaction after trauma which causes relatively high protein content in this subdural fluid collection. Comment Arachnoid cysts are benign lesions that occur in association with the central nervous system, both within the intracranial compartment (most common) as well as within the spinal canal. They are usually located in the subarachnoid space and account for 1% of all intracranial masses. The frontotemporal region is the most commonly affected.

Subdural hygroma associated with axillary cystic hygroma

We present a case of a 4-month-old girl with a history of a huge axillary cystic hygroma since birth, with elective surgical resection of the lesion and subsequent development of infection at the surgery site. During hospitalization for the infection, she developed seizures, a bulging fontanelle, increased head circumference, and widely separated cranial sutures. Brain imaging demonstrated new, large, bilateral subdural fluid collections with membrane enhancement around the left-sided collection. She was managed by subdural tap, bilateral craniotomy, broad-spectrum antibiotics, and subduroperitoneal shunt insertion. Ultimately, she had complete recovery without complications. This case adds to the spectrum of intracranial conditions that have been associated with cystic hygroma.

Targeted epidural patch with n-butyl cyanoacrylate (n-BCA) through a single catheter access site for treatment of a cerebral spinal fluid leak causing spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) usually occurs in the setting of a spontaneous cerebral spinal fluid (CSF) leak. We report the first description of a case of SIH caused by a...

Cortical gluing and Ringer lactate solution inflation to avoid cortical mantle collapse and subdural fluid collections in pediatric neurosurgery: safety and feasibility.

Subdural fluid collections following intraventricular and/or paraventricular procedures in pediatric neurosurgery are common and can be hard to treat. We describe our technique to close cortical defects by the aid of a fibrin adhesive and subsequent Ringer inflation with the aim to avoid cortical mantle collapse and to prevent the development of subdural fluid collections. We report the preliminary results of a prospective study on a consecutive series of 29 children who underwent 37 transcortical or transcallosal surgical procedures since 2008 in our department. In 17 procedures, we performed a transcortical approach on lesions, and in other 19 operations, we operated by a transcallosal. In 5/17 transcortical approaches (29%) and in 3/20 transcallosal approaches (15%), we observed a 5-mm-thick subdural fluid collection of the 5 patients with subdural fluid collections in the transcortical group, 3 patients (17%) underwent surgery for symptomatic or progressive subdural fluid collections. Of the 3 patients in the transcallosal group, a subduro-peritoneal shunt was necessary only for 1 patient (5%). At the very end of the treatment (including chemotherapy and radiotherapy), it was possible to remove the subduro-peritoneal shunt in all these patients because of disappearance of the subdural fluid collections. In pediatric patients after transcortical or transcallosal procedures, the use of a fibrin adhesive to seal surgical opening and subsequent inflation of the residual cavity with Ringer lactate solution to avoid cortical mantle collapse seems safe and appears to prevent the development of subdural fluid collections.

Schizencephaly Associated with Chronic Subdural Fluid Collection: Case Report

Schizencephaly is an uncommon congenital structural disorder of cerebral cortex caused by abnormal neuronal migration. Patients usually present with seizure disorders, hemiparesis, quadriparesis, cognitive deficits and mental troubles. Very rarely, schizencephaly is also associated with subdural fluid collection, and may present with mass effect. In this study we present a schizencephaly case with chronic subdural fluid collection. In our view, clefts may promote subdural fluid collection in schizencephaly patients and careful follow up of these patients is needed.

Efficacy of arachnoid plasty with collagen sheets and fibrin glue: An in vitro experiment and a case review.

Background:Postoperative subdural fluid collection sometimes occurs after clipping of cerebral aneurysms. Arachnoid plasty is used to prevent such postoperative complications; however, the optimal materials for arachnoid plasty remain unclear. In this study, we aimed to clarify the optimal materials for arachnoid plasty and report our experience of arachnoid plasty after clipping of unruptured aneurysms.Methods:In an in vitro experiment, adhesive strengths of three materials permitted for use in the intradural space, such as collagen sheets, gelatin sponge, and oxidized cellulose sheets, were measured by assessing their water pressure resistance. Then, 80 consecutive cases surgically treated unruptured cerebral aneurysms were retrospectively reviewed to examine the occurrence rate of postoperative subdural fluid collection.Results:The collagen sheet exhibited the greatest adhesive strength, so we used collagen sheets for the arachnoid plasty procedures. In all of these cases, arachnoid plasty was performed with fibrin glue-soaked collagen sheets. No postoperative subdural fluid collection, inflammation, or allergic reactions occurred in any case.Conclusions:The present study suggests that collagen sheet might be one of the optimal materials for arachnoid plasty. This technique is simple and may be effective to prevent subdural fluid collection after clipping.

Incidence and risk factors of chronic subdural hematoma after surgical clipping for unruptured anterior circulation aneurysms.

ObjectiveChronic subdural hematoma (CSDH) is a rare complication of unruptured aneurysm clipping surgery. The purpose of this study was to identify the incidence and risk factors of postoperative CSDH after surgical clipping for unruptured anterior circulation aneurysms.MethodsThis retrospective study included 518 patients from a single tertiary institute from January 2008 to December 2013. CSDH was defined as subdural hemorrhage which needed surgical treatment. The degree of brain atrophy was estimated using the bicaudate ratio (BCR) index. We used uni- and multivariate analyses to identify risk factors correlated with CSDH.ResultsSixteen (3.1%) patients experienced postoperative CSDH that required burr hole drainage surgery. In univariate analyses, male gender (p<0.001), size of aneurysm (p=0.030), higher BCR index (p=0.004), and the use of antithrombotic medication (p=0.006) were associated with postoperative CSDH. In multivariate analyses using logistic regression test, male gender [odds ratio (OR) 4.037, range 1.287-12.688], high BCR index (OR 5.376, range 1.170-25.000), and the use of antithrombotic medication (OR 4.854, range 1.658-14.085) were associated with postoperative CSDH (p<0.05). Postoperative subdural fluid collection and arachnoid plasty were not showed statistically significant difference in this study.ConclusionThe incidence of CSDH was 3.1% in unruptured anterior circulation aneurysm surgery. This study shows that male gender, degree of brain atrophy, and the use of antithrombotic medication were associated with postoperative CSDH.

Stricter indications are recommended for fenestration surgery in intracranial arachnoid cysts of children.

The indication of surgical treatment for intracranial arachnoid cysts (ACs) is a controversial issue. In this study, we reviewed surgical outcomes of intracranial ACs that were treated with endoscopic fenestration or microscopic fenestration, which are currently standard practices for surgical treatment of AC. In addition, we also evaluated the validity of current surgical indications. We analyzed pediatric patients under 18 years of age who underwent surgical management for intracranial AC between January 2000 and December 2011. Patients with a follow-up period of less than 1 year were excluded. A total of 75 patients were enrolled in this study. These patients were assessed by subjective symptoms and by a clinician's objective evaluation. The radiological assessment of AC after surgery was also evaluated. The median age of patients at the initial operation was 5 years. The median follow-up period was 38 months. The goal of surgery was achieved in 28% (21/75) of patients. The radiological alteration of AC after initial fenestration surgery was diverse. The results of the clinical and radiological assessments did not always coincide. A total of 35 complications occurred in 28 patients. Subdural fluid collection was the most common unexpected radiological complication. Our study showed that the fenestration procedure for AC produced unsatisfactory clinical improvements compared to the relatively high complication rate. Therefore, surgical treatment for AC should be strictly limited to patients who have symptoms directly related to AC.

Brain damage in commercial breath-hold divers.

BackgroundAcute decompression illness (DCI) involving the brain (Cerebral DCI) is one of the most serious forms of diving-related injuries which may leave residual brain damage. Cerebral DCI occurs in compressed air and in breath-hold divers, likewise. We conducted this study to investigate whether long-term breath-hold divers who may be exposed to repeated symptomatic and asymptomatic brain injuries, show brain damage on magnetic resonance imaging (MRI).Subjects and MethodsOur study subjects were 12 commercial breath-hold divers (Ama) with long histories of diving work in a district of Japan. We obtained information on their diving practices and the presence or absence of medical problems, especially DCI events. All participants were examined with MRI to determine the prevalence of brain lesions.ResultsOut of 12 Ama divers (mean age: 54.9±5.1 years), four had histories of cerebral DCI events, and 11 divers demonstrated ischemic lesions of the brain on MRI studies. The lesions were situated in the cortical and/or subcortical area (9 cases), white matters (4 cases), the basal ganglia (4 cases), and the thalamus (1 case). Subdural fluid collections were seen in 2 cases.ConclusionThese results suggest that commercial breath-hold divers are at a risk of clinical or subclinical brain injury which may affect the long-term neuropsychological health of divers.

Third Ventricle Tumors in Children

Pediatric III ventricular tumors constitute an heterogeneous group of neoplasms which share some specific characteristic from the surgical point of view. All these tumors are rare and tend to remain clinically silent until they produce hydrocephalus. By excepting colloid cyst, which may induce an abrupt deterioration in clinical condition because of their critical location in the CSF pathways, most of these tumors reach a considerable large size before being recognized. Macrocrania in infants, false localizing signs, namely sixth cranial nerve palsy, and, more rarely, hemiparesis secondary to transtentorial herniation are the most common clinical manifestations of the associated chronic hydrocephalus. Although the ventricular dilation is often a favorable feature for the surgical removal, the unfolding of the thinned cerebral cortex and the consequent hemispheric subdural fluid collections represent the most typical surgical complication of the surgical treatment often requiring additional surgical procedures. The most typical tumors are the choroid plexus and the colloid cysts, the first of them relatively common, the second exceedingly rare in the pediatric population. Subependymal giant cell astrocytomas and subependymal are also quite known intraventricular tumors arising from the subependymal glia. Finally, midline gliomas from the adjacent parenchima and craniopharyngiomas from the suprachiasmatic cistern may rarely invade the ventricular system. Finally in children, meningiomas and teratomas may expand within the III ventricle, often without any recognizable origin from the ventricular wall. Choroids plexus papillomas represent only 0.4 to 0.6% of intracranial tumors, but up to 90% to these tumors occur within the first 2 years of life. The young age, the commonly large size and hypervascularity of these tumors may require tailored surgical strategies, including staged surgical excision, preoperative embolization or chemotherapy. The control of impaired CSF dynamics still remains one difficult to solve postoperative complication. Bilateral forms carry the worst prognosis in terms of postoperative hydrocephalus and neurodevelopmental outcome. Colloid cysts are extremely rare in children. The endoscopic excision is nowadays preferred in the young patients due to the large experience generally available with the endoscopic technique in the pediatric department. Subpendymal giant cell astrocytomas, the typical neoplasms of tuberous sclerosis is characterized by an unpredictable clinical evolution. In growing tumors causing obstructive hydrocephalus surgical excision is regarded as the most reliable surgical option due to the multiple failures of bilateral CSF shunting therapy observed in the subjects undergoing the extrathecal CSF shunt placement. In summary, most of the III ventricle tumors in children are benign in nature. Consequently, the surgical treatment remains the most effective therapeutic options. However, the deep location of these tumors, the strict anatomical relationships with important functional structures, the frequently associated hydrocephalus, their large size together with their relatively rare occurrence which may prevent reaching a sufficient experience, suggest that these tumors should be dealt with in specialized pediatric neurosurgical centres.

Clinical therapeutic significance of early cranioplasty brain injury patients to de-compressive craniectomy with concurrent subdural effusion

Objective To introduce an effective treatment for postoperative contralateral subduraleffusion of traumatic brain injury patients with decompressive craniectomy.Methods 13 cases of traumatic brain injury with subdural effusion after decompressive craniectomy were treated with lumbar puncture or effusion holedrainage but invalid,then given early cranioplasty.Results subdural effusion occurred in the 13 cases of patients completely disappeared or reduced in the postoperative half months.Conclusion Early cranioplasty is an effective treatment for traumatic brain injury patients with contralateral subdural effusion after decompressive craniectomy. Key words: Traumatic subdural fluid collection; Decompressive craniectomy; Cranioplasty

Evaluation of simultaneous cranioplasty and ventriculoperitoneal shunt procedures

Some patients with severe brain swelling treated with decompressive craniectomy may develop hydrocephalus. Consequently, these patients require cranioplasty and a ventriculoperitoneal (VP) shunt to relieve the hydrocephalus. However, there is no consensus as to the timing of the cranioplasty and VP shunt placement in patients requiring both. The authors assessed the results of performing cranioplasty and VP shunt placement at the same time in patients with cranial defects and hydrocephalus. A retrospective review was performed of 51 patients who had undergone cranioplasty and VP shunt operations after decompressive craniectomy for refractory intracranial hypertension between 2003 and 2012 at the authors' institution. Patient characteristics, data on whether the operations were performed simultaneously, brain bulging, hydrocephalus, cranial defect size, and complications were analyzed. The overall complication rate was 43% (22 of 51 patients). In 32 cases, cranioplasty and VP shunt placement were performed at the same time. Complications included subdural hematoma, subdural fluid collection, and infection. The group undergoing cranioplasty and VP shunt placement at the same time had higher complication rates than the group undergoing the procedures at different times (56% vs 21%, respectively). The severity of complications was also greater in the former group. Patients with severe brain bulging had higher complication rates than did those without brain bulging (51% vs 0%, respectively). Cranial defect size, severity of hydrocephalus, indication for decompressive craniectomy, age, sex, and interval between decompressive craniectomy and subsequent operation did not affect complication rates. Patients undergoing cranioplasty and VP shunt placement at the same time had higher complication rates, especially those with severe brain bulging.

Teaching Neuro Images : A dangerous complication of spontaneous intracranial hypotension

A 43-year-old man presented with a nontraumatic orthostatic headache, spatial disorientation, and visual hallucinations ("colored flames"). General and neurologic examination were normal. Turbo spin echo T2-weighted MRI showed bilateral subdural fluid collection and venous sinus engorgement (figure, A), suggesting spontaneous intracranial hypotension (SIH). Two subdural hematomas were also found, the biggest (2.5 cm) with mass effect in the left hemisphere (figure, B). Spine MRI identified a small radicular cyst emerging from the left T1-T2 foramen as the putative cause of CSF leakage (figure, C and D). The patient underwent drainage of the largest hematoma with benefit. Though initially planned, epidural blood patch and surgical treatment of the radicular cyst were not performed because clinical and radiologic findings improved with hematoma drainage, bed rest, and hydration. At a 3-month follow-up, MRI documented complete resolution of the subdural collection and dimensional stability of the radicular cyst. SIH is often considered benign and treated conservatively,(1)but it can rarely manifest with serious complications requiring rapid surgical evaluation.(2).

Imaging of Postoperative Cranium: Normal and Abnormal Appearance

: This presentation aims to describe the imaging patterns of normal postoperative (post-op) cranium and usual and unusual complications of various cranial surgeries. Many radiologists are dealing with imaging of postoperative cranium in their daily practice. They should be familiar with various types of cranial surgeries, including burr holes, craniotomy, craniectomy, and cranioplasty, as well as normal postoperative changes and complications of each cranial surgery. Findings and procedure details: Imaging is of significant importance in the routine postoperative follow-up of neurosurgical cranial procedures. Computed tomography (CT) is the first choice imaging modality. However, magnetic resonance imaging (MRI) may be needed for early or better detection of some complications, especially for ischemia or infections. The most important mainstay of interpreting a post-op cranium is to distinguish normal post-op changes from complications. The first step is familiarity with the normal anatomy. Although the vast majority of post-op CT or MR images are not normal looking, most of their changes are expected (normal) post-op changes which do not adversely affect the patient outcome. Scalp swelling, simple pneumocephalus, small size hemorrhages or edema in surgical site, extradural or subdural fluid collections and dural or surgical site enhancement in early post-op period are examples of normal post-op changes. Some complications are seen only in special procedures (such as plunging of burr holes or extracranial herniation, trephine syndrome, or external brain tamponade in craniectomy) and others are common for all procedures. Skull fractures, infection (extradural abscess, subdural empyema, and bone flap infection), hemorrhage (subdural, extradural, parenchymal hematoma) and pneumocephalous are common complications of all neurosurgical procedures. The most important role of radiologists is to recognize the less common, but life threatening, post-op complications such as tension pneumocephalus, external brain tamponade and paradoxical herniation. Early and accurate diagnosis is essential for improving the outcome. Since some findings may be seen in asymptomatic patients (pseudocomplications), one should always consider the patients clinical status when interpreting the post-op images. Interpretation of post-op cranium images requires knowledge of the normal anatomy, types of craniosurgery, and differentiating normal post-op changes from complications. Reporting a complication, especially a life threatening one, always should be done with clinical correlation.

未破裂脳動脈瘤術後の慢性硬膜下血腫

The incidence of postoperative chronic subdural hematoma (CSH) after clipping surgery for unruptured intracranial aneurysm (UIA) is reported to be in the range of 1.8–13.3%. Recent reports revealed that an increase in subdural fluid collection (SFC) during the first postoperative week is a significant risk factor for CSH after UIA surgery. Accumulating evidence from various studies indicates the potential benefit of arachnoid plasty in the prevention of SFC/CSH after surgery for intracranial aneurysms. In addition, Gorei-san, a Kampo medicine that exerts a hydragogue effect through aquaporins, has been suggested as a useful option for conservative management of CSH in which symptoms are either absent or minimal. Here, we retrospectively analyze the effects of arachnoid plasty and Gorei-san on the prevention and management of postoperative CSH after clipping surgery for UIA. Between January 2008 and December 2012, 42 patients underwent clipping surgery for UIA in anterior circulation using front-temporal craniotomy. Arachnoid plasty was performed immediately after UIA clipping. Four patients (9.5%) developed CSH after the surgery. In one case, a head injury during the postoperative period caused CSH. By excluding this case, the true incidence of postoperative CSH in our study was 7.1%, which was consistent with data shown in previous reports of case series without arachnoid plasty. The previous reports, however, included symptomatic cases and cases requiring surgical intervention. In contrast, all CSH cases in the present study were asymptomatic and improved without surgical treatment. Among the four CSH cases, three received Gorei-san during the postoperative period. Preventive administration of Gorei-san was started in 10 patients who showed increasing SFC in the postoperative period (1–2 weeks). In nine of the 10 cases, SFC diminished in one to two months. The remaining case developed CSH, which was eventually cured with conservative management. Symptomatic cases of CSH after UIA surgery often require surgical evacuation. Data in the present study suggested that intraoperative arachnoid plasty in combination with Gorei-san administration in cases that show increasing postoperative SFC or evidence of asymptomatic CSH might help prevent such detrimental complications. Further studies are required to clarify the precise effects of this therapeutic approach.

Arachnoid Membrane Suturing for Prevention of Subdural Fluid Collection in Extracranial-intracranial Bypass Surgery.

ObjectiveWater-tight closure of the dura in extracranial-intracranial (EC-IC) bypass is impossible because the superficial temporal artery (STA) must run through the dural defect. Consequently, subdural hygroma and subcutaneous cerebrospinal fluid (CSF) collection frequently occur postoperatively. To reduce these complications, we prospectively performed suturing of the arachnoid membrane after STA-middle cerebral artery (STA-MCA) and evaluated the clinical usefulness.Materials and MethodsBetween Mar. 2005 and Oct. 2010, extracranial-intracranial arterial bypass (EIAB) with/without encephalo-myo-synangiosis was performed in 88 cases (male : female = 53 : 35). As a control group, 51 patients (57 sides) underwent conventional bypass surgery without closure of the arachnoid membrane. Postoperative computed tomography (CT) scan was performed twice in three days and seven days later, respectively, for evaluation of the presence of subdural fluid collection and other mass lesions.ResultsThe surgical result was excellent, with no newly developing ischemic event until recent follow-up. The additional time needed for arachnoid suture was five to ten minutes, when three to eight sutures were required. Post-operative subdural fluid collection was not seen on follow-up computed tomography scans in all patients.ConclusionArachnoid suturing is simple, safe, and effective for prevention of subdural fluid collection in EC-IC bypass surgery, especially the vulnerable ischemic hemisphere.