Interhemispheric Approach Research Articles

‘Ectopic’ suprasellar type IIa PRL-secreting pituitary adenoma

Ectopic pituitary adenomas (EPAs) are rare, and the suprasellar cistern seems to be the most common location. At this time, no detailed original classification, diagnosis, or treatment protocols for suprasellar pituitary adenomas (SPAs) have been described. A 19-year-old man showed visual disturbances and lack of libido for 3years, he suffered a sharp decline in vision with only light perception in the last week. Magnetic resonance imaging scans revealed a large suprasellar cystic lesion with a normal pituitary in the sella turcica. Endocrinological findings showed an extremely high prolactin level of 1250ng/mL. Because of the sharp decline in vision, the patient underwent total removal of the suprasellar lesion using a transfrontal interhemispheric approach. The tumor pedicle originated in the lower pituitary stalk without any connection to the anterior pituitary gland in the sella turcica, while the diaphragma sellae was incomplete. Clinical and endocrinological cure criteria were fulfilled and postoperative pathology confirmed a prolactin-secreting pituitary adenoma. Ectopic suprasellar pituitary adenomas (ESPAs) are extremely rare intracranial extracerebral tumors. SPAs can be classified into three types according to their origin and their relationship with surrounding tissue. Only type III is theoretically a true ectopic, based on previous reports. Thus, ESPAs are uncommon compared to other EPAs. Our case is the first reported case of a type IIa 'E'SPA and the first description of this subtype classification until now. The pars tuberalis may be different from the pars distalis, and each subtype of adenohypophyseal cells may have different migration characteristics, which leads to different proportions of each hormone-secreting subtype in SPAs and EPAs. Transsphenoidal surgery is minimally invasive, but transcranial surgery may remain a universal option for the treatment of suprasellar lesions.

Microsurgical Resection After Failed Gamma Knife Radiosurgery of Papillary Tumor of the Pineal Gland.

Abstract Primary papillary tumors of the pineal region (PTPR) are rare entities with distinct histopathological characteristics. Most common surgical approaches include the supra-cerebellar infratentorial corridor or the occipital interhemispheric approach. Gamma knife radiosurgery (GKRS) is an acceptable treatment modality for parenchymal tumors of the pineal gland, and often used as a primary treatment modality for asymptomatic and indolent lesions, and as an adjunct to surgical resection. In this presentation, we describe the surgical nuances of posterior interhemispheric approach in an elderly male with a previously failed empirical GKRS. Intraoperatively, the tumor was mostly avascular, presumed to be due to prior GKRS; however, a good tumor-brain interface allowed a gross total resection of the mass. Histopathological examination of the mass was consistent with PTPR. Post-operative course was uneventful and long-term follow up showed no signs of tumor recurrence. The video discusses radiological findings, clinic-pathological correlates, and emphasizes on key microsurgical techniques including the significance of patient positioning and incision type for meticulous resection of pineal tumors.

Anterior Midline Skull Base Meningiomas: Interhemispheric Approach versus the Different Classical Surgical Approaches—Clinical Outcomes

Backgrounds: Different surgical approaches have been used to remove anterior skull base meningiomas (ASBMs) such as olfactory groove (OG) and tuberculum sellae (TS) meningiomas. These tumors are traditionally resected through pterional (PT), lateral supraorbital (LS) approaches. The endonasal endoscopic (EE) approach has gained some attention in recent years. The interhemispheric (IH) approach represents another option that has been rarely described and even more rarely compared with other approaches.

Pterional or Subfrontal Access for Proximal Vascular Control in Anterior Interhemispheric Approach for Ruptured Pericallosal Artery Aneurysms at Risk of Premature Rupture

ObjectiveCases of a ruptured pericallosal artery aneurysm with a high risk of intraoperative premature rupture and technical difficulties for proximal vascular control require a technique for the early and safe establishment of proximal vascular control.MethodsA combined pterional or subfrontal approach exposes the bilateral A1 segments or the origin of the ipsilateral A2 segment of the anterior cerebral artery (ACA) for proximal vascular control. Proximal control far from the ruptured aneurysm facilitates tentative clipping of the rupture point of the aneurysm without a catastrophic premature rupture. The proximal control is then switched to the pericallosal artery just proximal to the aneurysm and its intermittent clipping facilitates complete aneurysm dissection and neck clipping.ResultsThree such cases are reported: a ruptured pericallosal artery aneurysm with a contained leak of the contrast from the proximal side of the aneurysm, a low-lying ruptured pericallosal artery aneurysm with irregularities on its proximal wall, and a multilobulated ruptured pericallosal artery aneurysm with the parasagittal bridging veins hindering surgical access to the proximal parent artery. In each case, the proposed combined pterional-interhemispheric or subfrontal-interhemispheric approach was successfully performed to establish proximal vascular control far from the ruptured aneurysm and facilitated aneurysm clipping via the interhemispheric approach.ConclusionWhen using an anterior interhemispheric approach for a ruptured pericallosal artery aneurysm with a high risk of premature rupture, a pterional or subfrontal approach can be combined to establish early proximal vascular control at the bilateral A1 segments or the origin of the A2 segment.

Outcome of Radical Surgical Resection for Craniopharyngioma with Hypothalamic Preservation: A Single-Center Retrospective Study of 1054 Patients.

A retrospective review of the surgical outcome for patients with craniopharyngioma (CP) treated in a single neurosurgical center with surgical resection using visualization to ensure hypothalamic preservation. The study included 1054 patients. Before 2003, a pterional cranial approach was preferred for 78% of patients; after 2004, the unifrontal basal interhemispheric approach was performed in 79.1% of patients. Complete tumor resection was achieved in 89.6% of patients; vision improved in 47.1% of patients who had preoperative vision impairment. However, diabetes insipidus worsened in 70.4% of patients and new-onset diabetes insipidus occurred in 29.7% of the remaining patients. Pituitary stalk preservation occurred in 48.9% of cases. There were 89.6% of patients with total tumor removal; 13.3% of patients showed tumor recurrence within an average of 2.8 years. Of 69 follow-up patients with a subtotal or partial resection, 94.2% showed tumor recurrence within an average of 4.3 months. Of the total patients, 82.3% fully recovered. This study has shown that radical surgical resection of CP using microsurgical excision can be effective with a good patient outcome without more limitations on each individual tumor of distinct features despite the impact of recent endoscopic techniques on CP surgery. The surgical approach depends on a direct and wider visualization of CP located in the midline with preserving hypothalamic structures by identifying some hypothalamic landmark structures. After surgery, most patients can resume their normal activities even after aggressive tumor removal, although patients require postoperative hormonal replacement.

Chapter 29 - Thalamic cavernous malformations

Cavernous malformations of the thalamus represent a particularly complex subset of cavernous malformations because of the highly eloquent nature of the involved tissue and their deep location. The decision about whether to operate on any individual lesion depends on the specific location of the lesion within the thalamus, the nature of the patient's symptoms, and the patient's history. When surgery is recommended, the approach must be chosen carefully. Each part of the thalamus is reached by a different surgical approach. These approaches include the orbitozygomatic approach to the anteroinferior thalamus, the anterior interhemispheric transcallosal approach to the medial thalamus, the anterior contralateral interhemispheric transcallosal approach to the lateral thalamus, the posterior interhemispheric transcallosal approach to the posterosuperior thalamus, the parieto-occipital transventricular approach to the lateral posteroinferior thalamus, and the suboccipital supracerebellar infratentorial/transtentorial approach to the medial posteroinferior thalamus. Careful attention to safe entry zones and image guidance can allow safe removal of these lesions when necessary.

未破裂脳動脈瘤クリッピング術における周術期痙攣の検討

Seizures, including generalized convulsions and simple and complex partial seizures, rarely occur after surgical clipping of unruptured cerebral aneurysms. We conducted a detailed investigation of cases of seizures after clipping for unruptured aneurysms. A total of 235 patients (78 men and 157 women; mean age, 63.0±9.1 years) with 251 aneurysms underwent surgical clipping of unruptured aneurysms. Intravenous administration of prophylactic antiepileptic drugs was continued for 1 or 2 days after surgery. Seventeen patients (6.7%) had seizures after surgery. Patients who underwent surgery through a transsylvian approach developed seizures significantly more frequently when compared with patients treated through other approaches, such as an interhemispheric approach (p=0.008). Onset of seizures occurred 3.5±2.5 days after surgery, and 13 patients (76.4%) developed seizures within 4 days. Three patients developed generalized seizures, 2 developed secondarily generalized seizures, and 12 developed partial seizures. Magnetic resonance imaging was obtained in 14 patients immediately after a seizure; 4 patients (28.5%) had high signals on diffusion-weighted imaging. Most of the patients discontinued antiepileptic drug therapy within 1 year after surgery. Because most patients with unruptured aneurysms are asymptomatic, seizures after surgery should be prevented whenever possible. Therefore, it is necessary to use appropriate prophylactic treatment for postoperative seizures.

Intraventricular Tumor Resection

Neurosurgeon Marcus Czabanka treats an intraventricular tumor found in a patient with persistent headaches by resecting the tumor via an interhemispheric transcallosal approach.

Anterior Temporal Artery-to-Anterior Cerebral Artery Bypass: Anatomic Feasibility of a Novel Intracranial-Intracranial Revascularization Technique.

Complex aneurysms of the anterior cerebral artery (ACA) may require a bypass procedure as part of their surgical management. Most current bypass paradigms recommend technically demanding side-to-side anastomosis of pericallosal arteries or use of interposition grafts, which involve longer ischemia times. The purpose of this study is to assess the feasibility of an anterior temporal artery (ATA) to ACA end-to-side bypass. Fourteen cadaveric specimens (17 ATAs) were prepared for surgical simulation. The cisternal course of the ATA was freed from perforating branches and arachnoid. The M3-M4 junction of the ATA was cut, and the artery was mobilized to the interhemispheric fissure. The feasibility of ATA bypass to the precommunicating and postcommunicating ACA was assessed in relation to the cisternal length and branching pattern of the middle cerebral artery. Successful anastomosis was feasible in 14 ATAs (82%). Three ATAs did not reach the ACA. These ATAs were branching distally and originated from the M3 (opercular) middle cerebral artery. In specimens where bypass was not feasible, the average cisternal length of the ATA was significantly shorter than the rest. ATA-ACA bypass is anatomically feasible and may be a useful alternative to other revascularization techniques in selected patients. It is technically simpler than A3-A3 in situ bypass. ATA-ACA bypass can be performed through the same pterional exposure used for the ACA aneurysms, sparing the patient an additional interhemispheric approach, required for the A3-A3 anastomosis.

Microsurgical strategy of invasive pituitary adenomas

Objective To analyze the efficacy of different surgical approach for invasive pituitary adenoma and to raise the rational microsurgical strategy. Methods We retrospectively analyzed the clinical data of 441 patients with invasive pituitary adenomas at the Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University from July 2012 to June 2015. The clinical manifestation, imaging data, surgical methods, microsurgical skills and prognosis were reviewed. Suprasellar invasive was identified in 310 patients, parasellar was in 293 patients and the sellar floor was in 187 patient. 318 patients underwent transsphenoidal surgery, while 123 patients were treated by craniotomy. In the cases of patients treated by craniotomy, the number of patients undergoing the subfrontal approach, the frontal lateral approach, the frontal temporal approach, the anterior interhemispheric approach and the callosal interforniceal approach was respectively 31, 50, 22, 11 and 9. Univariate analysis and Logistic regression analysis were used to evaluate the influencing factors of surgical approach for invasive pituitary adenoma. Results The suprasellar (P 15 cm3 (P<0.001) were the main factors to choose craniotomy, while the sellar floor (P<0.001) is the main factor to use transsphenoidal approach. The options of subfrontal approach, frontal lateral approach or frontal temporal approach were related to the parasellar (P<0.001) and width of the tumor (P=0.001). The height of the tumor (P<0.001) was associated with the selections of the subfrontal approach, the anterior interhemispheric approach or the callosal interforniceal approach. Conclusions The options of the surgical approach of invasive pituitary adenomas should be on the basis of preoperative patient status and imaging findings. Transsphenoidal surgery has unique advantages for excising the tumor which pushes the internal wall of the cavernous sinus - false tumor invasion . The frontal lateral approach takes a advantage of the subfrontal approach and the frontal temporal approach to remove the tumor in the cavernous sinus. The options of the anterior interhemispheric approach to remove tumor involving suprasellar space avoid the disconnection syndrome after the operation though the callosal interforniceal approach, and the gross-total resection rate is higher. Key words: Pituitary adenoma; Neurosurgical procedures; Surgical approach; Prognosis

Analysis and Long-Term Follow-Up of the Surgical Treatment of Children With Craniopharyngioma

To investigate the relationship between the operative approach, clinical pathological factors, and curative effect of the surgical treatment in the patients with craniopharyngioma; to provide a theoretical basis for determining the prognosis and reducing the recurrence rate during the long-term postoperative follow-up in children. This was a retrospective analysis of the clinical data of 92 children who underwent surgical treatment in our department from May 2011 to January 2005. Long-term follow-up was performed from 12 months to 8 years. The pterional approach was used in 49 patients, the interhemispheric approach in 20 patients, the corpus callosum approach in 16 patients, and the butterfly approach in 7 patients. Pathological classification was performed by hematoxylin and eosin stain staining of the pathological tissues and evaluated according to the different surgical approaches, MRI calcification status, calcification type, pathological type, whether radiotherapy was performed, postoperative recurrence, and death. For the pterion approach resection, there was near total resection in 46 patients (93.9%) with the lowest recurrence rate. The operative approach and postoperative recurrence rates were compared; the difference was statistically significant (P <0.05). For comparison of the operative approach and postoperative mortality, the difference was not statistically significant (P >0.05). There was not a significant difference between the MRI classification and postoperative recurrence rate (P >0.05). Comparing the degree of tumor calcification with the recurrence rate after operation and the mortality rate, the difference was statistically significant (P <0.05). The recurrence rate and mortality rate of adamantimous craniopharyngioma and squamous papillary craniopharyngioma in 2 groups following operation were compared, and the differences were statistically significant (P <0.05). Postoperative adjuvant radiotherapy was compared with the postoperative recurrence rate and mortality; the differences were statistically significant (P <0.05). The main effects on tumor recurrence include the choice of surgical approach and degree of calcification. The adamantimous craniopharyngioma relapse rate is higher, which could be because invasion of craniopharyngioma only occurs with adamantimous craniopharyngioma. Postoperative radiotherapy can significantly prolong the recurrence time and reduce the mortality rate of patients with craniopharyngioma.

The Posterior Transcallosal Approach to the Pineal Region and Posterior Third Ventricle: Intervenous and Paravenous Variants

There are a number of surgical approaches to the posterior third ventricle and pineal region, each with its associated advantages and disadvantages. To present our experience with the posterior interhemispheric transcallosal approach and to analyze the indications, technique, and outcomes. A retrospective study was conducted to identify and analyze all children and young adults who underwent the posterior transcallosal approach from July 2010 to March 2015. Perioperative data included patient demographics, signs and symptoms on presentation, tumor characteristics (type, origin, and size), complications, and clinical and radiographic outcome at final follow-up. Twenty-two patients (9 female, 13 male) were identified in 24 cases with a mean age of 10.5years (range, 3-32years). The most common tumor type was pineoblastoma (n = 6). Eleven patients underwent gross total resections; 11 underwent subtotal resections; and 2 tumors were biopsied. The intervenous operative corridor was used in 15 cases; the paravenous was used in 9. Of the 22 patients, 19 experienced 31 total postoperative events. There were 12 instances of contralateral weakness. Retraction-related hemiparesis was usually temporary; resection-related hemiparesis lasted longer. There were no complications related to occlusion of one or more bridging cortical veins or from thrombosis of 1 internal cerebral vein. Eight patients have died of tumor progression, and of the remaining 14 patients, only 1 patient to date has developed local progression. The posterior interhemispheric transcallosal approach allows resection of tumors located within the pineal region, posterior third ventricle, and thalamus. New postoperative neurological deficits can occur; however, many will improve significantly or resolve completely over time.

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

Bypass Revascularization Applied to the Posterior Cerebral Artery

The application of bypass procedures to the posterior cerebral artery (PCA) in combination with proximal clipping or trapping is a useful option for the treatment of complex posterior circulation aneurysms, especially those of the PCA. Because of its course around the midbrain through various cisterns, different approaches are required to access the PCA. The presented study analyzes a retrospective case series of bypass procedures to the PCA to investigate the relevant treatment strategies and their outcomes. Seven patients with bypass procedures to the PCA bypass were analyzed. The location of the aneurysms, approaches, site of anastomosis, bypass patency, pre- and postoperative modified Rankin Scale scores, and transient and permanent morbidity were assessed. Analyzed patients were treated for intracranial aneurysm located on the P2 (n= 3) or P3 (n= 2) of the PCA, bilateral vertebral artery dissecting aneurysm (n= 1) or internal carotid artery-posterior communicating artery aneurysm (n= 1). The following approaches were used: anterior temporal approach (n= 2), anterior temporal approach combined with subtemporal approach (n= 2), combined transpetrosal approach (n= 1), posterior interhemispheric approach (n= 1), and posterior interhemispheric approach with subtemporal approach (n= 1). All bypasses were patent. Permanent morbidity occurred in 2 patients via cognitive dysfunction (n= 1) and hemiparesis (n= 1). Bypass revascularization of the PCA territory is effective for the treatment of complex vascular lesions affecting the posterior circulation. To address the various surgical segments of the PCA, different approaches are required. Combined approaches allow access to the PCA proximal and distal from the lesion.

Combined Endoscopic and Microsurgical Interhemispheric Transcallosal Approach: A Minimally Invasive Strategy to Manage Complex Third Ventricular Lesions

Introduction: Surgical approaches to deep-seated brain pathologies, specifically lesions of the third ventricle, have always been a challenge for neurosurgeons. The endoscopic resection of intraventricular lesions has gained increasing popularity in recent years. However large, vascular, or extremely firm lesions are better approached microsurgically. In these cases, the transcallosal approach remains the most suitable option, to not violate the brain parenchyma, even if it carries a risk of postoperative cognitive and memory deficits in the event of bilateral fornical injury. In this background, the combined use of the endoscopic and microsurgical technique that requires a minimal callosotomy to reach the ventricular compartment, could combine the advantages of both techniques, then increasing the likelihood of a safe and complete resection.

Interhemispheric transcallosal transforaminal approach and its variants to colloid cyst of third ventricle: Technical issues based on a single institutional experience of 297 cases.

Context:Colloid cysts are benign intracranial lesions that usually involve the anterior third ventricle with varying appearance on imaging studies. The number of articles debating the origin of this tumor is surpassed by papers proposing the best modality available for its treatmentAim:The purpose of this study is to analyze the clinical presentation and surgical outcome of colloid cysts surgically managed over a period of thirty-two years and evaluate the technical issues based on our experience.Study Design:This is a retrospective case series study.Materials and Methods:This is a retrospective case series study on 297 consecutive patients with colloid cysts who were operated. The case records of all the patients were evaluated to record the clinical symptoms and signs, imaging findings, surgical procedure, complications and follow-up data.Results:There were 178 (60%) males and 119 (40%) females, their age ranging from 9 to 66 years with a mean age of 28 years. The mean duration of symptoms was 1.8 months. Raised intracranial pressure headache was the most common initial presenting symptom followed by visual blurring, memory disturbance and drop attacks with gait unsteadiness. The tumor was an incidental imaging finding in five patients (2%). While an interhemispheric transcallosal approach was used in 275 (92.6%) patients, it was trans-cortical in 22 (7.4%). Twenty-two patients required emergency surgery in view of worsening sensorium. Postoperative complications included memory impairment, limb weakness and seizures. Despite documented complete excision of the tumor in 6 cases, 8 patients had recurrence of tumor during follow-up.Conclusion:Colloid cysts are potential life threatening but benign lesions that can be removed safely with low morbidity and mortality through the interhemispheric transcallosal approach and its variants. The possibility for recurrence warrants, close imaging follow-up after surgery. It is essential for neurosurgeons to be familiar with the different transcallosal approaches to reach the third ventricle especially for a posteriorly situated cyst and a narrow foramen of Munro.

Comparative Anatomical Study on Operability in Surgical Approaches to the Anterior Part of the Third Ventricle

Surgery of the third ventricle still represents a challenge in modern neurosurgery. To optimize the surgical planning, some aspects, related to ventricular anatomy, have to be taken into consideration. An operability score could represent a preoperative tool to evaluate these variables to choose a tailored surgical approach. We compared the transcallosal transforaminal approach and the combined interhemispheric subcommissural translamina terminalis approach (CISTA) to the anterior part of the third ventricle, applying the operability score. Compared with the transcallosal transforaminal approach, the CISTA provides a statistically significant improvement in terms of depth of surgical field, surgical angle of attack, and maneuverability arc considering as 4 approach-related critical structures: the optic chiasm (P value: <0.0001, <0.0001, <0.0001, respectively), the anterior commissure (P value: <0.0001, <0.0001, <0.0001 respectively), the tuber cinereum (P value: <0.0001, 0.0224, 0.0173), and the interthalamic adhesion (P value: 0.2917, <0.0001, <0.0001 respectively). Tumors originating from the anterosuperior part of the third ventricle can be easily approached through a transcallosal transforaminal route, whereas lesions arising from the anteroinferior portion of the third ventricle might be safely and effectively approached through the CISTA.

Predicting the necessity of anterior communicating artery division in the bifrontal basal interhemispheric approach.

BackgroundThe anterior communicating artery (ACoA) often limits surgical exposure in the anterior interhemispheric approach. Although division of the ACoA has been proposed occasionally, it is rarely practiced, and criteria for such a surgical maneuver remain unknown. Our purpose was to identify key factors that allow for predicting the necessity of controlled ACoA division in the bifrontal basal interhemispheric approach.MethodTwenty-two consecutive patients who underwent surgery via the bifrontal basal interhemispheric approach for removal of various pathologic brain lesions were examined. First, tumors were dichotomized into central and lateral lesions. Next, three tumor parameters were compared between cases with and without ACoA division in each, the central and lateral lesion groups, respectively: tumor volume, tumor depth (defined as distance between the ACoA and posterior tumor margin) and tumor laterality angle (defined as the geometric angle between the lateral tumor margin and sagittal midline).ResultsTumor volume was not related in a statistically significant manner to ACoA division in both the central (P = 0.06) and lateral (P = 0.13) lesion groups, respectively. However, tumor depth was significantly correlated with ACoA division in the central lesion group (P = 0.01), whereas in the lateral lesion group, the tumor laterality angle showed a significant correlation with ACoA division (P = 0.04).ConclusionsOur results suggest that controlled ACoA division may be required in central lesions with a depth of 38 mm or more and in lateral lesions with an angle of 23 degrees or more as defined in this study. Two key factors were thus identified that may predict the necessity of controlled ACoA division before surgery.

Removal of craniopharyngioma via fronto-basal interhemispheric approach.

The effectiveness and safety of fronto-basal interhemispheric approach in treating craniopharyngioma were evaluated. In this retrospective study, the safety and effectiveness of fronto-basal interhemispheric approach for surgical resection of craniopharyngioma in 20 patients was analyzed. Of the 20 patients, 12 were men and 8 were women, aged 15–65 years, with an average age of 42.5 years. The course of disease ranged from 1 to 36 months. The craniopharyngioma tumor was completely removed through surgical resection in 18 patients (90%) and partially removed in 2 patients. The pituitary stalk was preserved in 18 patients and 1 patient succumbed during the study period due to large area pulmonary embolism. In conclusion, fronto-basal interhemispheric approach provides better access to the tumor that grows in the sella-hypothalamus and anterior third ventricle region. Using this approach, tumors can be resected while preserving the vital structures such as the pituitary stalk and hypothalamus.

Giant colloid cyst of the third ventricle: challenges in management

Giant colloid cysts (size > 3 cm) are very rare with only few reported cases in the literature. We report a case of 44 year female who presented with features of raised intracranial pressure, memory and gait disturbances. CT and MR imaging showed a large colloid cyst at foramen of Monro leading to obstructive hydrocephalus. The patient underwent right interhemispheric transcallosal-transforaminal approach and complete excision of the cyst. For a large size of colloid cyst complete surgical excision is recommended. However deep midline location, proximity to the vital structures and giant size of the lesions make surrounding vital structures vulnerable for injury.