Translamina Terminalis Approach Research Articles

Impact of three surgical approaches on the therapeutic efficacy of intraventricular craniopharyngiomas: a single-center retrospective analysis.

This study aimed to investigate the therapeutic efficacy of three different surgical approaches for the treatment of intraventricular craniopharyngiomas (IVCs). The three surgical approaches investigated in this study were the endoscopic endonasal approach (EEA), pterional trans-lamina terminalis approach (PTA), and interhemispheric trans-lamina terminalis approach (ITA). Patient demographics, preoperative symptoms, endocrine and hypothalamic status, tumor characteristics, and surgical outcomes were analyzed and compared among the different surgical groups. A total of 31 patients with IVCs were included in the analysis, with 12 patients in the EEA group, 8 patients in the ITA group, and 11 patients in the PTA group. The mean follow-up time was 39 ± 23months. Statistical analysis of the data revealed significant differences in the gross total resection (GTR) rate among the three surgical groups (P = 0.033). The GTR rate for the EEA group was 100%, that for the ITA group was 88%, and that for the PTA group was 64%, which was the lowest rate observed. After surgery, only 8.3% of the patients in the EEA group did not experience new postoperative hypopituitarism, while the percentages in the ITA and PTA groups were 75% and 73%, respectively (P = 0.012). Finally, we found that postoperative hypopituitarism may be related to the transection of the pituitary stalk during the operation (P = 0.020). Based on the results of this study, we recommend using the EEA and the ITA instead of the PTA for the surgical resection of IVCs. Furthermore, the appropriate surgical approach should be selected based on the tumor's growth pattern.

Proposed System for Selection of Surgical Approaches for Craniopharyngiomas Based on the Optic Recess Displacement Pattern

Craniopharyngiomas remain surgically challenging because of the strong adhesion to vital neurovascular structures. We propose a system for the selection of surgical approaches based on the optic recess (OR) displacement pattern to facilitate the surgical planning and obtain the optimum visual and endocrinological outcomes. Craniopharyngiomas were divided into three types based on the OR displacement pattern: superior, anterior, and involvement types. Selected surgical approaches and patient outcome were retrospectively reviewed according to these classifications. Visual and endocrinological outcomes were compared between the groups. This study included 26 patients with primary craniopharyngiomas who underwent surgery at our institution, classified into 11 anterior, 11 superior, and 4 involvement types. Extended endoscopic endonasal approach provided excellent exposure infero-dorsal aspect of the chiasm for manipulation of the dissection plane in the anterior and superior types with midline location. Unilateral subfrontal approach was required for tumor of the superior type with lateral extension. Interhemispheric translamina terminalis approach (TLA) could provide safe dissection under direct vision of strong adhesion at the superior aspect of the chiasm in the involvement type. Visual and endocrinological outcomes were better in the involvement type compared with the superior and anterior types. Visual outcome was significantly correlated with preoperative visual function. Craniopharyngiomas with the involvement type are indicated for TLA to achieve the best visual and endocrinological outcome. Our classification of OR displacement pattern is useful to select the optimal surgical approach for craniopharyngiomas more accurately and concisely, especially in cases with third ventricular extension.

New perspectives in the surgical neuroanatomy of the subfrontal translamina terminalis approach

New perspectives in the surgical neuroanatomy of the subfrontal translamina terminalis approach

Expanded Transsphenoidal Trans-Lamina Terminalis Approach to Tumors Extending Into the Third Ventricle: Technique Notes and a Single Institute Experience

ObjectThe trans lamina terminalis approach (TLTA) has been described as a way to remove third ventricular tumors. The aim of this paper was to analyze the feasible outcomes of TLTA applied to tumors extending into the third ventricle in our institute.MethodsSuprasellar tumors (n = 149) were treated by the extended endonasal approach from September 2019 to December 2020 in Beijing Tiantan Hospital. Eleven of the tumors were treated by TLTA or TLTA via the trans-chiasm-pituitary corridor (TCPC). The surgical technique notes of TLTA were described and indications and outcomes of the approach were analyzed.ResultsThere were 11 patients enrolled in the study, six with papillary craniopharyngiomas, two with adamantinomatous craniopharyngiomas, one with a germinal cell tumor (GCT), one with cavernous malformation and one with chordoid glioma. Four of the patients received a radical resection by TLTA alone, while seven of them received TLTA via the TCPC. Gross total resection was achieved in eight patients (72.7%), and partial resection in three patients (27.3%). Visual function was improved in four of the 11 patients (36.4%), was unchanged in five patients (45.5%), and deteriorated in two patients (18.2%). New-onset hypopituitarism occurred in seven patients (63.3%) and new-onset diabetes insipidus occurred in two patients (18.2%). Electrocyte imbalance were observed in six patients (54.5%) at post-operative week 2. There were no surgery-related deaths or cerebrospinal fluid leaks. Postoperative intracranial infection was observed in one patient (9.1%), and during the follow-up period, tumor recurrence occurred in one patient (9.1%).ConclusionThe expanded TLTA provides a feasible suprachiasm corridor to remove tumors extending into the third ventricle, especially for craniopharyngiomas. Sound understanding of the major strengths and limitations of this approach, as well as strategies for complication avoidance, is necessary for its safe and effective application.

Comparative analysis of anterior third ventricle approaches

Background. Third ventricle tumors are uncommon and account for only 0.6 - 0.9% of all the brain tumors7. In 1921, Dandy was the first neurosurgeon who successfully removed a colloid cyst from the third ventricle through a posterior transcallosal approach. Despite their unfavourable locations, these tumours can be removed successfully by proper knowledge of anatomical landmarks and by choosing the appropriate approach. Methods. We performed a retrospective analysis of all patients (17 patients) who underwent surgery for anterior third ventricular masses between March 2018 to March 2020 in the Dr Ram Manohar Lohia Institute of Medical Science Lucknow, Uttar Pradesh. Results: The most common symptom in our cases was headache, which was present in all (100%) patients, nausea/vomiting in 7 (41%), history of recurrent episodes of drop attacks in 4 (23%), h/o seizure in 2 (11.7%), visual disturbance in 1 (5.4%), memory disturbance in 1 (5.4%) and urinary incontinence in 1 (5.4%) patient. 6 patients were operated with transcallosal-transforaminal approach, 1 patient was operated with transcallosal interforniceal approach, 3 patients were operated with transcortical-transforaminal approach, 1 patient was operated with subfrontal translamina terminalis approach, 1 patient was operated with transcallosal-transchoroidal approach, 5 patients were operated with endoscopically. Gross total excision was achieved in 15 (88%) patients while in 2 (11.7%) patients subtotal resection was done due to their adherence to choroid plexus and optic chiasm. The most common post-operative complication was endocrine dysfunction in the form of diabetes insipidus. Conclusions. Anterior Third ventricular tumours are mostly benign and best treatment modality is surgical resection. When we analyzed the results of various approaches, we found that despite their unfavourable location, the results were satisfactory for different tumours of different location in the anterior third ventricle, when treated with the carefully planned microsurgical or endoscopic approach with proper knowledge of anatomical landmarks.

SURG-24. NOVEL MALLEABLE FORCIPES FOR ENDOSCOPIC ASSISTED TECHNIQUE IN PEDIATRIC BRAIN TUMORS

Recent advances in optical devices and surgical instruments have been applied to neurosurgery. Even with modifications, one of the most serious risks is injury of neuronal and vascular structure caused by operation of surgical instruments in a narrow surgical field. Fixed instruments are not practical for pediatric brain tumor surgeries because the length of the curved or angled tip portion is limited because of the narrow entrance. We developed a novel malleable forceps to resolve the difficulties related to microsurgical procedures. The malleable forceps has two shafts with a sharp cup at the tip. The entire forceps was made of stainless steel, with a silver and nickel alloy inserted between 10 and 40 mm from the tip. In the alloy part, the surgeon can flex the forceps freely using a special cylinder. The special cylinder is useful to prevent from slipping of the cups of tip. The maximum angle that can be bent is 70 degrees vertically. We also developed a monoshaft malleable forceps. We used these flexible forcipes in the case of various pediatric brain tumors including craniopharyngioma. We performed tumor resection by anterior interhemispheric trans-lamina terminalis approach. After procedure of tumor resection using microscope, endoscope inserted around the pituitary stalk. The piece of calcified tumor could be easily removed without any complications. These forcipes can be deformed to an appropriate angle and can be applied to various cases, especially pediatric brain tumors.

Surgical Anatomy Applied to the Resection of Craniopharyngiomas: Anatomic Compartments and Surgical Classifications

Resective surgery remains the main treatment option for most patients with craniopharyngiomas. Understanding of the microsurgical anatomy of the sella and suprasellar region and its relationship with these tumors is necessary to achieve effective surgical treatment and minimize complications. In this article, we review the surgical anatomy related to craniopharyngiomas and divide it in 5 compartments according to tumor extension. Endoscopic and microsurgical dissection were performed in 3 freshly injected cadaver heads at the Weill Cornell Surgical Innovations Laboratory (New York, New York, USA) and at the Surgical Skills Center at Mount Sinai Hospital (Toronto, Ontario, Canada). Tumor extension was classified as 1) inferomedial or sellar, 2) superomedial or suprasellar, 3) lateral or sylvian, 4) posterior or interpeduncular/prepontine, and 5) intraventricular. The selection of surgical approaches is discussed based on the anatomic nuances of each these regions. In addition, we reviewed the literature regarding previous anatomic classifications for resection of craniopharyngiomas. Different approaches should be considered according to tumor extension into different compartments. Purely sellar tumors are amenable to endoscopic transsellar approaches, whereas those with a suprasellar extension require an extended transtuberculum approach. In some of those patients, a narrow chiasm-pituitary window may block access to the tumor and a transcranial translamina terminalis approach may be favored. Tumors occupying the interpeduncular fossa may pose a significant challenge for an endoscopic endonasal approach and transcranial approaches. Transcavernous approaches and anterior and posterior clinoidectomies may be required for adequate exposure in such patients. Translamina terminalis and/or transcallosal approaches are recommended for resection of purely intraventricular tumors. Tumors extending into the lateral compartment should be considered for transcranial frontotemporal approaches. The understanding of such anatomic nuances aids in the selection of the most appropriate surgical approach and in the prevention of potential complications. Because most craniopharyngiomas are midline lesions, the endoscopic endonasal approach represents an excellent approach for most of those tumors. However, transcranial approaches should be considered for tumors with extension into the lateral compartment and for selected tumors involving the ventricular compartment (purely intraventricular tumors and those with extension to the foramen of Monro and/or lateral ventricles).

Translamina Terminalis Approach to the Hypothalamus Using Supraorbital Craniotomy: Technical Note and Comparison with Other Surgical Corridors.

Objectives:Approaches to the hypothalamus and anterior third ventricle are variable. We present a technical note on access of the hypothalamus using the trans-lamina terminalis approach by supraorbital craniotomy in a patient who had a hypothalamic cavernoma and presented to us with recurrent hemorrhage.Patients and methods:The trans-lamina terminalis approach, including anatomical landmarks and surgical steps through a supra-orbital craniotomy, is described and a comparison with other surgical corridors is discussed.Results:The supraorbital trans lamina terminalis approach allowed an effective access to the hypothalamic lesions. This approach provided a safe and minimally invasive corridor for gross total resection of the lesion since trespass of viable brain tissue is avoided. One clinical case illustrates the feasibility of the approach allowing complete removal of a cavernoma without surgery related neurological of endocrinological deficits.Conclusions:The supra-orbital craniotomy for trans-lamina terminalis approach is a valid surgical choice for hypothalamic lesions. The major strengths of this approach include minimal brain retraction and direct end-on view; however, the long and narrow surgical corridor requires some technical familiarization. The clinical outcomes are comparable to other surgical corridors.

Neurological and neuropsychological outcome after resection of craniopharyngiomas.

Craniopharyngiomas are rare and benign tumors of the sellar and/or parasellar region. Primary treatment involves resection followed by adjuvant radiotherapy. While the grade of resection was frequently analyzed following surgery, the neurological outcome and especially neuropsychological deficits and quality of life have been neglected for many decades. Therefore, the authors retrospectively analyzed their patient series and prospectively assessed neuropsychological outcome and quality of life following resection of craniopharyngiomas in adults. In total, 71 patients (39 men and 32 women) with a mean age of 49 years were enrolled in the retrospective analysis. In addition, 36 of the 71 patients were included in the prospective arm of the study and underwent neurological and neuropsychological testing as well as quality of life (36-Item Short-Form Health Survey; SF-36) assessment. Factors influencing outcome were identified and correlations calculated. Resection was performed mostly using a pterional (41.6%, 47/113 surgical procedures) or bifrontal translamina terminalis (30.1%, 34/113 surgical procedures) approach. Following surgery, visual acuity was significantly improved (> 0.2 diopters) in 32.4% (23/71) of patients, or remained stable in 45.1% (32/71) of patients. During long-term follow up, 80.3% (57/71) of patients developed pituitary insufficiency, particularly involving the corticotropic and thyrotrophic axes. In total, 75% (27/36) of patients showed neuropsychological deviations in at least 1 test item. In particular, attentiveness, cognitive speed, and short-term memory were affected. Referring to the SF-36 score, quality of life was affected in both the mental and physical score in 19.4% (7/36) and 33.3% (12/36), respectively. The risk factors that were identified were a tumor volume larger than 9 cm3, tumor extension toward/into the third ventricle or the brainstem, and resection using a bifrontal translamina terminalis or left-sided approach. This study demonstrated that resection of craniopharyngiomas is frequently associated with postoperative neuropsychological deficits and hence an impaired quality of life. In addition to tumor size and extension toward/into the third ventricle or the brainstem, selection of the surgical approach may play a crucial role in the patient's neuropsychological outcome and quality of life.

Anterior communicating artery division in the endoscopic endonasal translamina terminalis approach to the third ventricle: an anatomical feasibility study.

Endonasal endoscopic approaches (EEA) to the third ventricle are well described but generally use an infrachiasmatic route since the suprachiasmatic translamina terminalis corridor is blocked by the anterior communicating artery (AComA). The bifrontal basal interhemispheric translamina terminalis approach has been facilitated with transection of the AComA. The aim of the study is to describe the anatomical feasibility and limitations of the EEA translamina terminalis approach to the third ventricle augmented with AComA surgical ligation. Endoscopic dissections were performed on five cadaveric heads injected with colored latex using rod lens endoscopes attached to a high-definition camera and a digital video recorder system. A stepwise anatomical dissection of the endoscopic endonasal transtuberculum, transplanum, translamina terminalis approach to the third ventricle was performed. Measurements were performed before and after AComA elevation and transection using a millimeter flexible caliper. Multiple comparison statistical analysis revealed a statistically significant difference in vertical exposure between the control condition and after AComA elevation, between the control condition and after AComA division and between the AComA elevation and division (p < 0.05). The mean difference in exposed surgical area was statistically significant between the control and after AComA division and between elevation and AComA division (p < 0.01), whereas it was not statistically significant between the control condition and AComA elevation (NS). The anatomical feasibility of clipping and dividing the AComA through an EEA has been demonstrated in all the cadaveric specimens. The approach facilitates exposure of the suprachiasmatic optic recess within the third ventricle that may be a blind spot during an infrachiasmatic approach.

Interhemispheric, Translamina Terminalis Approach for the Resection of Suprasellar Cavernous Malformation.

Objectives The current video presents the nuances of an interhemispheric, translamina terminalis approach for the resection of suprasellar cavernous malformation. Design The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging. Setting The patient was treated by a skull base team at a teaching academic institution. Participants The case refers to a 64-year-old female who presented with vision loss and confusion, and was found to have a suprasellar mass, with imaging characteristics consistent with a cavernous malformation of the third ventricle. Main Outcome Measures The main outcome measures consist of the reversal of the patient symptoms (vision loss and confusion), the recurrence-free survival based on imaging, as well as the absence of any complications. Results The patient's mental status improved slightly after surgery. There was no evidence of recurrence. Conclusions The interhemispheric, translamina terminalis approach is safe and effective for the resection of suprasellar cavernous malformations. The link to the video can be found at: https://youtu.be/z6RSAM_GnBA .

Combined Interhemispheric and Transsylvian Approach for Resection of Craniopharyngioma.

We present a 37-year-old male case of cystic suprasellar huge craniopharyngioma, who presented with significant memory disturbance due to obstructive hydrocephalus. Combined interhemispheric and pterional approach was chosen to resect huge suprasellar tumor. Interhemispheric trans-lamina terminalis approach was quite effective to resect third ventricular tumor, while pterional approach was useful to dissect tumor out of basilar perforators and stalk. The link to the video can be found at: https://youtu.be/BoYIPa96kdo .

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.

Microsurgical Management of Craniopharyngiomas via a Unilateral Subfrontal Approach: A Retrospective Study of 177 Continuous Cases

To evaluate the outcomes of 177 cases of craniopharyngioma (CP) treated via a unilateral subfrontal approach. A total of 177 continuous microscopic surgeries were performed by the senior author (Y.X.). The tumors were divided into 6 groups using the diaphragm sellae and the third ventricle floor as the anatomic references. The preoperative, postoperative, and long-term follow-up data were analyzed to evaluate the extent of tumor resection, recurrence, and functional status. The subfrontal-basal approach was used in 169 (91.4%) cases. Total resection was achieved in 167 (94.4%) cases. A total of 158 patients were followed from 6 to 130 months. There were 3 perioperative and 23 delayed deaths. Twenty-two patients had tumor recurrence (12.7%). The progression-free survival was 80% at 5 years and 72% at 10 years. The overall survival was 84.0% at 2.5 years and 83.2% at 10 years. There was a significant increase of pituitary dysfunction after total resection. Neurologic function was stable in most patients. Rate of hypothalamic dysfunction and mortality were higher in patients with intraventricular CPs. Of the surviving patients, 91.8% were living independently with acceptable morbidities at the end of the study. Most CPs extend along the intrasellar-suprasellar-third ventricle axis. A subfrontal-basal approach is a simple, safe, and effective approach to resecting CPs extending along the vertical axis. A translamina terminalis approach is an ideal corridor to resect intraventricular CP. The benefit of radical resection remains controversial, especially for CPs involving the infundibulotuberal region.

Radical resection of a craniopharyngioma via the extradural anterior temporal approach with zygomatic arch osteotomy.

Background:Though the extradural anterior temporal approach (EDATA) with zygomatic osteotomy is useful, there are only few reports of this approach being used for craniopharyngioma resection. Herein, we report our surgical case series and the technical importance of EDATA for the radical removal of a craniopharyngioma.Methods:We report 7 cases of craniopharyngiomas treated surgically between April 1999 and October 2015. The surgical approaches, clinical presentation, pre and postoperative radiographic examination results, surgical outcomes, and morbidity were analyzed.Results:The mean follow-up period was 89.1 months. The surgical approach was EDATA with zygomatic osteotomy in 4, combined interhemispheric translamina terminalis approach (IHTLA) and trans-sylvian anterior temporal approach (ATA) in 2, and IHTLA in 1 patient. Complete tumor resection was achieved in all cases, without any recurrence during the follow-up period. Transient morbidities were oculomotor nerve palsy in 2, and meningitis and hydrocephalus in 1 patient. There was 1 case of permanent morbidity due to hydrocephalus that needed a ventriculoperitoneal shunt, and 1 case of blindness on the operative side. Visual acuity and visual field improved in 4 cases, showed no change in 2 cases, and deteriorated in 1 case. Though the pituitary stalk was preserved in 2 cases, all 7 cases needed total hormone replacement therapy.Conclusion:EDATA with zygomatic osteotomy ensures sufficient mobility of the internal carotid artery, and provides a good lateral and look up operative view. Hence, it can be used effectively for radical resection of craniopharyngiomas through the opticocarotid space and retrocarotid space.

The Anterior Subcallosal Approach to Third Ventricular and Suprasellar Lesions: Anatomical Description and Technical Note

Surgical access to the third ventricle is challenging, given the depth of the operative field and close proximity of vital neural structures that must be traversed. For anterior third ventricular lesions, approach options include anterior transcallosal or transcortical, subfrontal, frontotemporal, or endonasal. The subcallosal approach, a translamina terminalis approach, is unique in that the surgical corridor is just below the corpus callosum, minimizes retraction and preserves corpus callosum integrity. Case examples are provided, and an anatomical study delineating the dimensions of the surgical corridor is performed. Two latex-injected cadaver heads were used to describe the subcallosal corridor. A magnetic resonance imaging scan was obtained and registered with neuronavigation for correlative anatomical illustration. Depth, dimensions, and cross-sectional area were measured for the subcommunicating and supracommunicating corridors. The surgical depth for anterior transcallosal, subcallosal, and subfrontal approaches was 7.5 cm, 7.7 cm, and 7.6 cm respectively. The average corridor dimensions for the subcallosal approach were 14.75 × 6.63 mm compared with 8.88 × 5.38 mm for the subcommunicating corridor. Cross-sectional area of the subcommunicating corridor was 30.62 mm(2) compared with 80.42 mm(2) for supracommunicating. This was easily enlarged to 156.62 mm(2) with gentle retraction. The anterior subcallosal approach is a safe approach for lesions of the third ventricle that avoids splitting the corpus callosum and resecting unnecessary brain and minimizes brain retraction. This corridor is superior to the traditional subfrontal approach in terms of working space and compares favorably to the anterior transcallosal approach without disrupting the corpus callosum.

Prognostic factors for recurrence and complications in the surgical management of primary chordoid gliomas: A systematic review of literature

ObjectiveChordoid gliomas (CG) are rare neoplasms which frequently arise within the third ventricle. Surgery remains the mainstay treatment for CG. The present study comprehensively reviews all reported cases of CG within the literature in order to identify risk factors for surgical complications and tumor recurrence. MethodsA comprehensive search on MEDLINE (OVID and PubMed), Scopus, Embase, and Web of Science was conducted following PRISMA guidelines to identify all reported cases of CG. ResultsA total of 81 patients met the study criteria which comprised of 33 males and 48 females. Median age at diagnosis was 48 years with a range from 5 to 72 years, and mean tumor size was 3.1cm. Biopsy, subtotal resection (STR), and gross total resection (GTR) were achieved in 8, 34, and 33 patients, respectively, with six cases not reporting extent of resection (EOR). Thirteen patients underwent adjuvant radiotherapy. Postoperative complications were noted in 30 cases (37%), with new onset diabetes insipidus being the most common. Postoperative morbidity was not associated with age, tumor size, or extent of resection. A trans-lamina terminalis approach demonstrated a strong trend towards decreased overall rates of postoperative morbidity compared to other approaches (p=0.051). GTR was associated with improved progression-free survival (PFS; p=0.028), while adjuvant radiotherapy, age, tumor size and proliferative index were not predictive of patient outcomes. ConclusionGTR should be the primary goal for the management of CG, as it is associated with improved rates of tumor control without an increased rate of postoperative complications. Surgical approach was a stronger predictor of complication rates than extent of resection. Morbidity remains high, and future studies to further elaborate on factors predictive of postoperative complications are critical.

Trans-lamina terminalis approach for third ventricle and suprasellar tumours

BackgroundThe trans-lamina terminalis (TLT) approach to the suprasellar region and third ventricle is complex, with risks of visual and hormonal deficits. However, the postoperative deficits might not be directly related to opening of the lamina terminalis but to the close relationship of tumours with vital neural and vascular structures. The analysis of results using this approach was the objective of this study. Material and methodsThe TLT approach was used in 29 patients (18 craniopharyngiomas, 5 astrocytomas, 5 germinomas and 1 ganglioglioma). The extent of tumour removal, mortality and morbidity (especially visual or hormonal deficits) were studied. ResultsComplete tumour removal was achieved in 15 patients, subtotal extensive removal (more than 90%) in 9 cases and partial removal in 5 cases. Panhypopituitarism developed in 22 patients. Total tumour removal was associated with the development of endocrinological disturbances. There was worsening or the onset of new visual field defects in 4 cases. Postoperative endocrine and visual deficits were in the range generally described regarding surgery for tumours in this region. ConclusionThe TLT approach allows for extensive removal of third ventricle and suprasellar tumours, without increased risks of visual and hormonal deficits, compared to those described regarding surgery for lesions in this region.

Anterior callosal section is useful for the removal of large tumors invading the dorsal part of the anterior third ventricle: operative technique and results

Large tumors invading the dorsal part of the anterior third ventricle are difficult to manage. The anterior transcallosal approach is usually used to manage these tumors. In our clinic, anterior callosal section was combined with the anterior interhemispheric (AIH) translamina terminalis approach for these tumors with excellent results. The AIH approach is useful for removing tumors in and around the anterior part of the third ventricle. However, AIH alone is insufficient for large tumors invading the dorsal part of the anterior third ventricle. In such situations, simple anterior callosal section enables the neurosurgeon to extirpate the caudal part of the tumors deeply hidden from operative field, sparing the foramen of Monro, fornix, etc. We treated four large tumors (malignant teratoma, recurrent chordoid glioma, recurrent papillary tumor of pineal region occupying the third ventricle, and paraventricular meningioma) without major complications. The malignant teratoma case exhibited no recurrence with >10years follow-up. The chordoid glioma and papillary tumor of pineal region were totally removed. The meningioma was subtotally removed except only a small tumor around the bilateral anterior cerebral artery. This simple technique is a new way to manage difficult large lesions in and around the third ventricle.

The transventricular preforniceal approach for exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle

Surgical treatment of large exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle remains a challenging task for neurosurgeons. In particular, when the tumor extends from the chiasmatic region upward to the foramen of Monro, damage to the fornix and other neurovascular structures is a major concern. To describe the technique used in the transventricular preforniceal surgical approach to remove the superior and superoposterior part of the tumor in the third ventricle for treatment of exophytic chiasmatic/hypothalamic astrocytoma. The transventricular preforniceal approach was used in two cases of exophytic chiasmatic/hypothalamic astrocytoma. The approach is summarized in 4 procedures: 1) exposure of the anterior horn of the lateral ventricle by the transcallosal approach, 2) identification of the foramen of Monro and the fornix, 3) incision of the septum pellucidum or the wall of the lateral ventricle, in front of the columns of the fornix, and 4) removal of the tumor through the space between the anterior commissure and the columns of the fornix. Because the tumor compressed the foramen of Monro posteriorly and stretched the space between the anterior commissure and the columns of the fornix, the posterosuperior part of the tumor in the third ventricle was successfully removed through the surgical corridor in front of the columns of the fornix. In both cases, tumors were successfully removed using this approach without damaging the fornix and the anterior commissure. Residual tumor was removed using an anterior interhemispheric translamina terminalis approach in a two-stage surgery. The transventricular preforniceal approach can be applied for removing the superior part of exophytic chiasmatic/hypothalamic astrocytomas, because the space between the anterior commissure and the fornix is stretched by the tumor, providing an appropriate surgical corridor.