Bifrontal Interhemispheric Approach Research Articles

Mini anterior interhemispheric approach for A3 segment distal anterior cerebral artery aneurysms

IntroductionAneurysms of the A3 segment of the distal anterior cerebral artery (DACA), in relation to the genu of the corpus callosum, are specific sub-group which pose unique surgical challenges due to their discrete anatomical location. We describe a mini-anterior interhemispheric approach which can be safely utilised to clip these aneurysms rather than the traditional bifrontal approach. MethodsRetrospective analysis of the clinical and radiological data of ruptured DACA-A3 aneurysms operated between 2014 and 2021 at our institute. A curvilinear scalp incision within the hairline followed by raising small, unilateral, free frontal bone flap, avoiding the opening of frontal sinus. Superior sagittal sinus is displaced medially, inter-hemispheric dissection carried out with posterior trajectory and small callosotomy is performed. DACA is skeletonised, proximal control is established, and the A3 aneurysm is dissected and clipped. ResultOur cohort of 18 patients had a definite female preponderance (F:M::2:1) with mean age of 55.6 years. On admission three patients were categorized as WFNS Grade I, thirteen in Grade II, and two in Grade III for subarachnoid haemorrhage. All the patients had evidence of blood in the interhemispheric fissure; intraparenchymal haemorrhage was seen in seven, with intraventricular haemorrhage in six patients. Within the A3 segment six aneurysms were infragenu (inferior), eight were at the genu (anterior) and four were supragenu (superior). Two (11.1%) elderly patients succumbed post-surgery following ischemic infarcts and associated complications. At the time of follow-up at 3 months of the remaining sixteen (72.2%) patients, thirteen had a good outcome (mRS 0–3) and three (16.7%) had a poor outcome (mRS > 3). ConclusionThe mini anterior interhemispheric is an effective minimally invasive alternative for A3 segments aneurysms and helps to avoid the complications of the conventional bifrontal interhemispheric approach.

Postoperative Clipping Status after a Pterional versus Interhemispheric Approach for High-Positioned Anterior Communicating Artery Aneurysms.

ObjectiveWhen treating high-positioned anterior communicating artery (ACoA) aneurysms, pterional-transsylvian and interhemispheric approaches are both viable options, yet comparative studies of these two surgical approaches are rare. Accordingly, this retrospective study investigated the surgical results of both approaches. MethodsTwenty-four patients underwent a pterional approach (n=11) or interhemispheric approach (n=13), including a unilateral low anterior interhemispheric approach or bifrontal interhemispheric approach, for high-positioned ACoA aneurysms with an aneurysm dome height >15 mm and aneurysm neck height >10 mm both measured from the level of the anterior clinoid process. The clinical and radiological data were reviewed to investigate the surgical results and risk factors of incomplete clipping. ResultsThe pterional patient group showed a significantly higher incidence of incomplete clipping than the interhemispheric patient group (p=0.031). Four patients (36.4%) who underwent a pterional approach showed a postclipping aneurysm remnant, whereas all the patients who experienced an interhemispheric approach showed complete clipping. In one case, the aneurysm remnant was obliterated by coiling, while follow-up of the other three cases showed the remnants remained limited to the aneurysm base. A multivariate analysis revealed that a pterional approach for a large aneurysm with a diameter >8 mm presented a statistically significant risk factor for incomplete clipping. ConclusionFor high-positioned ACoA aneurysms with a dome height >15 mm and neck height >10 mm above the level of the anterior clinoid process, a large aneurysm with a diameter >8 mm can be clipped more completely via an interhemispheric approach than via a pterional approach.

Bifrontal Interhemispheric Approach Involving Cutting the Superior Sagittal Sinus for Distal Anterior Cerebral Artery Aneurysms

The unilateral interhemispheric approach for distal anterior cerebral artery aneurysms presents several risks, such as postoperative venous infarction due to occasional sacrifice of parasagittal bridging vein and postoperative frontal lobe damage due to retraction force. To overcome these risks, we used a bifrontal craniotomy with straight dural incision and cutting of the superior sagittal sinus. We retrospectively reviewed 61 patients (42 unruptured and 19 ruptured A2 and A3 aneurysms) who under aneurysm clipping through bifrontal interhemispheric approach between March 2007 and December 2017. There were 35 A2 aneurysms and 27 A3 aneurysms, and mean size of aneurysms was 5.45 mm. The modified bifrontal interhemispheric approach involved 3 steps: bifrontal craniotomy of centrobasal portion of the frontal bone, ligation and division of anterior one third of the superior sagittal sinus, and approaching the aneurysm via the interhemispheric space. All patients underwent computed tomography on postoperative days 3 and 7 for evaluation of brain retraction damage or venous infarction. Among patients with ruptured aneurysms, 79% had a favorable outcome (Glasgow Outcome Scale score 4 or 5) 6 months after primary subarachnoid hemorrhage; all patients with unruptured aneurysms had favorable outcomes. Surgical outcome was strongly related to preoperative neurologic Hunt and Hess grade. Three patients had poor outcomes due to poor Hunt and Hess grade on admission (grade 3 in 2 patients, grade 4 in 1 patient). Follow-up CT showed that venous infarction did not occur in any of the patients. Modified bifrontal interhemispheric approach may be a safe and effective method for treating A2 and A3 aneurysms with relatively good clinical outcome and no surgery-related complications.

Anterior Interhemispheric Approach for Olfactory Groove Meningioma

Objective: To evaluate the surgical technique with bifrontal interhemispheric approach for total removal of tumor in olfactory groove meningioma (OGM). Methods: This study described a case of a 38-year-old woman with bilateral blindness, anosmia, and behaviour changes. Imaging studies show a tumor mass in midfrontal base. Surgery using a bifrontal interhemispheric approach was performed and total removal was achieved and postoperative computed tomography (CT) scan was performed to confirm the result. Histopathological findings established a diagnosis of meningioma. Results: A coronal skin incision behind the hairline was utilized. The scalp was elevated, taking care to reserve the vascularized pericranium medial to the linea temporalis of each side, and preserving the 2 supraorbital nerves. Eight burr holes were used, with the two initial holes made on each side of the orbitotemporal region, and the other four holes at the midline. A bifrontal craniotomy was performed. The tumor was first detached from its attachment with bipolar cautery and debulked. During this step, the main tumor feeder arteries from the anterior and posterior ethmoidal artery were interrupted, and the tumor devascularized. Total tumor removal through surgical intervention was achieved and confirmed by head CT-scan postoperatively. Conclusions: This case report supports the suitability of the bifrontal interhemispheric approach for OGM resection with additional radiation therapy. Keywords: Anterior interhemispheric approach, olfactory groove meningioma DOI: 10.15850/ijihs.v4n2.838

Suprasellar Hemangioblastoma

A 59-year-old woman presented with disturbance of consciousness and decreased visual acuity caused by a suprasellar mass identified on MRI. A bifrontal interhemispheric approach allowed removal of the top and lateral sides of the tumor from the wall of the third ventricle. The hypothalamus appeared to be the origin of the mass, which proved to be hemangioblastoma, a rare tumor in this location.

Saccular Aneurysm of the Azygos Anterior Cerebral Artery: Three Case Reports

The azygos anterior cerebral artery, a rare anomaly in the circle of Willis in which only a single vessel supplies the medial aspects of both anterior cerebral hemispheres, is closely associated with saccular aneurysms. We present three cases of azygos anterior cerebral artery aneurysms among the 781 cerebral aneurysms surgically treated at our institution in an 11-year period. These three cases all involved elderly women who presented with subarachnoid hemorrhage. Conventional cerebral angiography and CT angiography revealed small saccular aneurysms at the distal ends of the azygos anterior cerebral arteries. These aneurysms were clipped successfully using a bifrontal interhemispheric approach. Hence, the pathogenesis of these particular aneurysms relating to hemodynamic change, associated anomalies, and surgical pitfalls is discussed with review of literature.

Recurrent Solitary Fibrous Tumor of the Falx Cerebri With Intraventricular Extension-Case Report-

A 61-year-old male presented with a recurrent solitary fibrous tumor (SFT) arising from the falx cerebri with intraventricular extension manifesting as nausea and vomiting. Magnetic resonance imaging showed the heterogeneously enhanced tumor in the falx, which extended to the bilateral lateral ventricles and the third ventricle. Total tumor removal was performed via the bifrontal interhemispheric approach. Histological examination showed mostly spindle cells with rich intercellular fibers. Immunohistochemical examination showed strong staining for CD34 in the cytoplasm but no staining for epithelial membrane antigen. Reexamination of the two previous tumor specimens, previously identified as fibrous meningioma, found SFT. The differential diagnosis of SFT in the central nervous system from fibrous meningioma and hemangiopericytoma requires immunohistochemistry and electron microscopy.

Surgical treatment of craniopharyngiomas: experience with 168 patients.

The goal of this study was to assess the outcome of surgical management in 168 consecutive patients harboring craniopharyngiomas treated between January 1983 and April 1997. In 148 patients undergoing initial (primary) surgery, the pterional approach was most frequently used (39.2%), followed by the transsphenoidal approach (23.6%). For large retrochiasmatic craniopharyngiomas, the bifrontal interhemispheric approach was used increasingly over the pterional approach and led to improved surgical results. Total tumor removal was accomplished in 45.7% of transcranial and 85.7% of transsphenoidal procedures. The main reasons for incomplete removal were attachment to and/or infiltration of the hypothalamus, major calcifications, and attachment to vascular structures. The success rate in total tumor removal was inferior in the cases of tumor recurrence. The operative mortality rate in transcranial surgery was 1.1% in primary cases and 10.5% in cases of tumor recurrence. No patient died in the group that underwent transsphenoidal surgery. The rate of recurrence-free survival after total removal was 86.9% at 5 years and 81.3% at 10 years. In contrast, the 5-year recurrence-free survival rate was only 48.8% after subtotal removal and 41.5% after partial removal. Following primary surgery, the actuarial survival rate was 92.7% at 10 years, with the best results after complete tumor removal. At last follow up, 117 (79%) of 148 patients who underwent primary surgery were independent and without impairment. Total tumor removal while avoiding hazardous intraoperative manipulation provides favorable early results and a high rate of long-term control in craniopharyngiomas.

Neuropsychological Results of Craniopharyngioma Surgery in Adults: A Prospective Study

Background The optimal management of craniopharyngiomas is a topic of ongoing debate. Supporters of limited surgery for craniopharyngiomas claim that more radical approaches are afflicted with adverse neuropsychological sequelae. Since prospective studies on this issue have not yet been performed, we assessed neuropsychological functioning in adults before and after craniopharyngioma surgery. Methods Thirteen adults with an age range of 17–76 years (mean, 45 years) were included in the study. Surgery included a transcranial procedure in 10 patients. The bifrontal interhemispheric approach predominated ( n = 7). Neuropsychological evaluation was performed before and 3 months after surgery. The test battery was adjusted to evaluate function related to structures in the operative trajectory and at the tumor site. Results A complete tumor removal was accomplished in eight patients and subtotal removal in three patients. IQ scores for verbal intelligence were in the normal range and not affected by surgery (mean IQ score preoperative: 106.8; postoperative 107.4). In 12 of 13 patients, immediate recall, delayed recall and recognition memory were not impaired after surgery. Postoperative results for abstract thinking were in the normal or above-normal range. Cognitive speed was impaired in three patients preoperatively and in two patients postoperatively. Overall results were significantly better after surgery. Word fluency was not affected by surgery. Quality of life for the category “sleep” was impaired preoperatively, and this improved after surgery. Otherwise, quality of life was normal both before and after surgery. Conclusions Neuropsychological performance and quality of life are generally not impaired after surgical removal of craniopharyngiomas. The findings support the attitude that the initial therapy of craniopharyngiomas should be an attempt at total removal.

Surgical treatment of craniopharyngiomas. Part I. Experience with 168 patients

The surgical management of 168 consecutive patients harboring craniopharyngiomas treated between January 1983 and April 1997 is described. In 148 patients undergoing initial (primary) surgery, the pterional approach was most frequently used (39.2%) followed by the transsphenoidal approach (23.6%). For large retrochiasmatic craniopharyngiomas, the bifrontal interhemispheric approach was used increasingly over the pterional approach and led to improved surgical results. Total tumor removal was accomplished in 45.7% of transcranial and 85.7% of transsphenoidal procedures. The main reasons for incomplete removal were attachment and/or infiltration of the hypothalamus, major calcifications, and attachment to vascular structures. The success rate in total tumor removal was inferior in the cases of tumor recurrence. The operative mortality rate in transcranial surgery was 1.1% in primary cases and 10.5% in cases of tumor recurrence. No patient died in the group undergoing transsphenoidal surgery. The rate of recurrence-free survival after total removal was 86.9% at 5 years and 81.3% at 10 years. In contrast, the 5-year recurrence-free survival rate was only 48.8% after subtotal removal and 41.5% after partial removal. Following primary surgery, the actuarial survival rate was 92.7% at 10 years, with the best results after complete tumor removal. At last follow up, 117 (79%) of 148 patients who underwent primary surgery were independent and without impairment. Total tumor removal while avoiding hazardous intraoperative manipulation provides favorable early results and a high rate of long-term control in craniopharyngiomas.

Modified bifrontal interhemispheric approach to aneurysms of the anterior communicating artery with the use of a trephine craniotomy. A review of personal experience with 25 cases.

A modified microsurgical bifrontal interhemispheric approach (small trephine craniotomy) for clipping of aneurysms of the anterior communicating artery (ACoA) is described. This approach has been used in a series of 23 patients with ACoA and 2 patients with distal anterior cerebral artery aneurysms. Feasibility, indications and problems related to this approach to ACoA aneurysms are assessed. Twenty-one patients (84%) made an excellent or good recovery. The result was poor in an 80-year-old patient who was in grade 3 pre-operatively. Three patients of this series died: one of them was pre-operatively in grade 4 and died from pneumonia; the other two died as consequence of unrelated ailments. Incidence and extent of vasospasm was within the normal range, corresponding to the amount and distribution of subarachnoid blood clots. From our experience it can be concluded that this approach is safe and feasible for patients with ACoA aneurysms graded 1-2 (Hunt-Kosnik's grading system) and evaluated as group 1-2 of Fisher's CT classification. But it is not recommended for patients with larger amounts of subarachnoid blood clots. Advantages of this microapproach to ACoA aneurysms are: a) minimal brain damage, b) adequate visualization and anatomical orientation, c) preservation of the olfactory nerves and the gyrus rectus, d) reduced operative time, e) easy clip application to aneurysms pointing in any direction.

Bifrontal interhemispheric approach to aneurysms of the anterior communicating artery.

The authors review their experience with the bifrontal interhemispheric approach in 603 cases of single anterior communicating artery (ACoA) aneurysms and describe the operative technique. With this approach, the olfactory tracts are dissected, and both A1 segments of the anterior cerebral arteries are identified subfrontally. The interhemispheric fissure is then dissected and A2 segments are followed from the distal portion toward the ACoA complex. Following the administration of a combination of mannitol, vitamin E, and dexamethasone, a temporary clip is placed on at least the dominant A1 segment prior to dissection of the aneurysm itself. Once the aneurysm has been completely freed from the surrounding structures, the neck is ligated and clipped. If the aneurysm ruptures during surgery, temporary clips are placed on both A1 and A2 segments bilaterally and the operation proceeds in a completely dry field. With this method, it is possible to occlude any of the intracranial vessels for up to 40 minutes within 100 minutes of drug administration. To prevent the possibility of rerupture and the development of vasospasm in the period before aneurysm surgery, the authors have adopted a policy of performing ultra-early operations within 48 hours of the onset of symptoms. Among the 257 cases operated on during the 9 years since 1975, one-fifth have been operated on within 48 hours of rupture, and the in-hospital mortality rate has been only 4.3% (11 cases). Follow-up studies have shown that 87% of the 246 surviving patients have returned to useful lives.