Quadrigeminal Cistern

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Juha Hernesniemi - One of the best experts on this subject based on the ideXlab platform.

  • unedited microneurosurgery of a pineal region neuroepithelial cyst
    Surgical Neurology International, 2019
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Neuroepithelial cysts are benign, well-circumscribed, nonenhancing CSF-like masses that might virtually present in any intracranial location. Common locations are the frontal lobe, thalamus, midbrain and pons, vermis, the lateral and fourth ventricles, and the choroid fissure (Choroid fissure cysts). Usually asymptomatic, cysts in the posterior fossa have been reported to cause cranial nerve palsies, focal brainstem dysfunction, and hydrocephalus. Supratentorial cysts might cause seizures or focal motor and/or sensory deficits. Histopathological examination reveals that neuroepithelial cysts are lined by ependymal (columnar epithelium) or choroid plexus cells (low cuboidal epithelium). The differential diagnosis includes enlarged perivascular spaces, infectious cyst-neurocysticercosis, porencephalic cyst, and arachnoid cyst. Case Description A patient with a symptomatic histologically confirmed pineal region neuroepithelial cyst underwent park bench position and a right supracerebellar infratentorial approach. The pineal region was accessed over the right cerebellar hemisphere and the lesion was identified after a lateral opening of the Quadrigeminal Cistern. After a careful dissection of the lesion, the cyst was pulled out with long ring microforceps and long sharp bipolar forceps; both assisted by a thumb-regulated suction tube. A complete lesion was removed in a piece and meticulous attention was paid to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful. The patient underwent rehabilitation without recurrence of the lesion. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery into the pineal region for this very rarely documented pineal region neuroepithelial cyst. Videolink http://surgicalneurologyint.com/videogallery/pineal-cyst-4.

  • Unedited microneurosurgery of a pineal region ependymoma.
    Surgical Neurology International, 2018
    Co-Authors: Joham Choque-velasquez, Juha Hernesniemi
    Abstract:

    Background: Ependymomas are rarely located in the pineal region. The 2016 WHO classification of tumors of the central nervous system includes five ependymal tumors, the grade I subependymoma and mixopapillary ependymoma, the grade II ependymoma, the grade II-III ependymoma RELA fusion-positive, and the grade III anaplastic ependymoma. However, this grading system has been controversial with respect to its reproducibility and clinical significance and it is estimated that further studies of the molecular characteristics of ependymoma will provide more precise and objective classification. Herein, we present an unedited microneurosurgery of a gross total removed WHO grade II ependymoma. Case Description: A patient with a histologically confirmed WHO grade II ependymoma underwent a sitting praying position and a supracerebellar infratentorial paramedian approach. Under high magnification, the pineal region was accessed over the right cerebellar hemisphere. A tight dorsal membrane of the Quadrigeminal Cistern was opened laterally with microscissors. Tissue samples were obtained with ring microforceps for histological study. Internal debulking of the tumor was performed with the combination of the suction tube and bipolar forceps aiming to open the posterior wall of the third ventricle. Concentric retraction of the tumor with ring forceps was associated with medial and inferior dissection of its cleavage plane with the thumb-regulated suction tube. Similarly, the lateral border of the lesion was dissected with a combination of the suction tube and bipolar forceps. Once, the tumor was detached from the surrounding tissue, soft but continuous traction with ring forceps was required to pull out this lesion in a single piece. Small remnants were removed as well and the apparent origin zone of the tumor was detached with bipolar forceps. Meticulous attention was paid for the hemostasis and few minutes were considered to observe any bleeding site. Finally, some pieces of surgicel covered small bleeding dots. The postoperative course was uneventful with only slight double vision that improved gradually. The patient did not receive radiochemotherapy and is alive and free of recurrence >10 years after surgery. Conclusion: This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery into the pineal region for this very rarely documented pineal region ependymoma. Videolink: http://surgicalneurologyint.com/videogallery/pineal-tumor-4/.

  • unedited pineal cyst microneurosurgery
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Pineal cysts are benign lesions of the pineal gland without a clear etiology. Currently, different approaches are described to deal with pineal region lesions and particularly with pineal cysts. Although endoscopic procedures are becoming more frequent, some technical advantages of the microsurgical resection still make it the gold standard. Our aim was to demonstrate the efficiency and safety of our microsurgical technique into deep brain territories under the principle "simple, clean, and preserving the normal anatomy." Herein, we present an unedited microneurosurgery of a histologically confirmed large benign pineal cyst. Case description A patient with antidepressant medication, psychotic attacks, memory problems, and progressively intense headache along the last months underwent sitting praying position and supracerebellar infratentorial paramedian approach. Under high magnification, the pineal region was accessed over the right cerebellar hemisphere. A lateral focused opening of the Quadrigeminal Cistern and the posterior wall of the pineal cyst were followed by partial aspiration of the cystic content. Small vessels running around the cyst were carefully dissected, and few of those attached to the wall were coagulated and cut. After careful devascularization of the lesion, the cyst was detached and pulled out using soft and continuous traction with a long ring microforceps in the right hand and thumb-controlled suction tube in the left one. The final steps included meticulous attention to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful and the patient improved dramatically with resolution of the headache and progressive reduction of psychiatric medication. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe pineal cyst surgery. Videolink http://surgicalneurologyint.com/videogallery/pineal-cyst/.

  • unedited microneurosurgery of a cavernous malformation of the pineal region
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Cavernous malformations are low-flow vascular malformations comprised of clusters of dilated sinusoidal channels lined with endothelial cells. The tortuous blood vessels also called vascular caverns lack muscular and elastic layers, and are filled by blood at different stages of thrombosis. Hemosiderin and gliosis often surround cavernomas. However, no neural tissue is present inside the lesion. Magnetic resonance images of cavernomas reveal a pathognomonic popcorn appearance produced by multiple small hemorrhages. Developmental venous anomalies are associated in around 30% of the cases. Cavernomas are very prevalent lesions ranging from 0.4 to 0.8% of the population. However, those located in the pineal region are very rare. Herein, we present the microsurgical treatment of a histologically confirmed cavernous malformation of the pineal region. Case description A 33-year-old patient with a pineal region cavernoma and progressive hydrocephalus underwent right supracerebellar infratentorial paramedian approach in a sitting praying position. The surgical planning did not require neuronavigation, but anatomical landmarks for the proper approach. Under high magnification, the pineal region was accessed over the superior cerebellar surface. After a focused lateral opening of the dorsal membrane of the Quadrigeminal Cistern, small vessels running in the posterior wall of the third ventricle were carefully dissected. A yellowish hemosiderin staining tissue allowed us to recognize the vicinity of the lesion. A small cottonoid delimitated the posterior border of the malformation, nonetheless, the superior limits underwent microdissection to release some cerebrospinal fluid from the third ventricle. A precise marginal dissection with bipolar forceps, microdissectors, and a thumb-regulated suction tube encircled the lesion. Gently traction of the lesion with ring microforceps associated further detachment of the cavernoma with the suction tube. Cotton dissection and water dissection technique were useful as well. A piecemeal resection, which is indicated in lesions with a deep and eloquent location, allowed us a complete removal of the cavernoma. Accurate hemostasis and continuous saline irrigation maintained a clean surgical field along the procedure. The gliotic tissue was left behind to prevent damage of the surrounding structures. Under endoscopic vision, remnants in the lower margins of the operative field were carefully evaluated. Finally, the surgical area was flushed with saline irrigation to detect any bleeding, and a small piece of tachosil was placed over the cavity. The postoperative course was uneventful. The hydrocephalus resolved after surgery and it did not require any further procedure. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author Juha Hernesniemi considers essential when performing an efficient and safe surgery for cavernous malformation of the pineal region. Videolink http://surgicalneurologyint.com/videogallery/iii-ventricle-cavernoma/.

  • unedited microneurosurgery of a mixed germ cell tumor of the pineal region
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Germ cell tumors comprise a heterogeneous group of neoplasms, classified as germinomas and nongerminomatous germ cell tumors based on clinicopathological features. The nongerminomatous group of tumors includes embryonal carcinoma, endodermal sinus tumor (yolk sac tumor), choriocarcinoma, mature and immature teratoma, and mixed germ cell tumors with more than one element. While germinomas are radiation-sensitive tumors, all other tumors have less response to radiotherapy, and it is suggested that gross total resection improves their overall survival and tumor-free survival rates. Herein, we present the microsurgical management of a histologically confirmed mixed-germ cell of the pineal region. Case description A patient with a mixed germ cell tumor underwent sitting praying position and midline supracerebellar infratentorial approach. After opening of the dura, a midline cerebellar vein was coagulated and cut, and the pineal region was accessed over the superior cerebellar surface. A tight reactive dorsal membrane of the Quadrigeminal Cistern was widely opened with subsequent evaluation of the neurovascular structures by intraoperative angiography. Under high microsurgical magnification between both basal veins, the dorsal wall of the fibrotic and solid tumor was coagulated and opened aiming an internal debulking of the lesion. Water dissection and cotton dissection were useful tools to separate the lateral borders of the tumor from the surroundings. Bipolar coagulation was helpful shrinking the tumor as well. The superior borders of the lesion, firmly attached to the roof of the third ventricle, required a careful evaluation. Ring microforceps in the right hand and thumb-regulated suction tube in the left one allowed us to pull out the tumor in a piece under soft and continuous traction with dissection of the cleavage plane. The superior attachment of the tumor was coagulated and cut. Finally, bipolar coagulation and small pieces of surgicel ensured a proper hemostasis. Postoperatively, the patient had a partial gaze palsy that improved gradually. The patient underwent adjuvant radiochemotherapy and currently is alive, free of tumor recurrence >12 years after surgery. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery for a mixed germ cell tumor. Videolink http://surgicalneurologyint.com/videogallery/pineal-tumor-5.

Joham Choquevelasquez - One of the best experts on this subject based on the ideXlab platform.

  • unedited microneurosurgery of a pineal region neuroepithelial cyst
    Surgical Neurology International, 2019
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Neuroepithelial cysts are benign, well-circumscribed, nonenhancing CSF-like masses that might virtually present in any intracranial location. Common locations are the frontal lobe, thalamus, midbrain and pons, vermis, the lateral and fourth ventricles, and the choroid fissure (Choroid fissure cysts). Usually asymptomatic, cysts in the posterior fossa have been reported to cause cranial nerve palsies, focal brainstem dysfunction, and hydrocephalus. Supratentorial cysts might cause seizures or focal motor and/or sensory deficits. Histopathological examination reveals that neuroepithelial cysts are lined by ependymal (columnar epithelium) or choroid plexus cells (low cuboidal epithelium). The differential diagnosis includes enlarged perivascular spaces, infectious cyst-neurocysticercosis, porencephalic cyst, and arachnoid cyst. Case Description A patient with a symptomatic histologically confirmed pineal region neuroepithelial cyst underwent park bench position and a right supracerebellar infratentorial approach. The pineal region was accessed over the right cerebellar hemisphere and the lesion was identified after a lateral opening of the Quadrigeminal Cistern. After a careful dissection of the lesion, the cyst was pulled out with long ring microforceps and long sharp bipolar forceps; both assisted by a thumb-regulated suction tube. A complete lesion was removed in a piece and meticulous attention was paid to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful. The patient underwent rehabilitation without recurrence of the lesion. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery into the pineal region for this very rarely documented pineal region neuroepithelial cyst. Videolink http://surgicalneurologyint.com/videogallery/pineal-cyst-4.

  • unedited pineal cyst microneurosurgery
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Pineal cysts are benign lesions of the pineal gland without a clear etiology. Currently, different approaches are described to deal with pineal region lesions and particularly with pineal cysts. Although endoscopic procedures are becoming more frequent, some technical advantages of the microsurgical resection still make it the gold standard. Our aim was to demonstrate the efficiency and safety of our microsurgical technique into deep brain territories under the principle "simple, clean, and preserving the normal anatomy." Herein, we present an unedited microneurosurgery of a histologically confirmed large benign pineal cyst. Case description A patient with antidepressant medication, psychotic attacks, memory problems, and progressively intense headache along the last months underwent sitting praying position and supracerebellar infratentorial paramedian approach. Under high magnification, the pineal region was accessed over the right cerebellar hemisphere. A lateral focused opening of the Quadrigeminal Cistern and the posterior wall of the pineal cyst were followed by partial aspiration of the cystic content. Small vessels running around the cyst were carefully dissected, and few of those attached to the wall were coagulated and cut. After careful devascularization of the lesion, the cyst was detached and pulled out using soft and continuous traction with a long ring microforceps in the right hand and thumb-controlled suction tube in the left one. The final steps included meticulous attention to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful and the patient improved dramatically with resolution of the headache and progressive reduction of psychiatric medication. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe pineal cyst surgery. Videolink http://surgicalneurologyint.com/videogallery/pineal-cyst/.

  • unedited microneurosurgery of a cavernous malformation of the pineal region
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Cavernous malformations are low-flow vascular malformations comprised of clusters of dilated sinusoidal channels lined with endothelial cells. The tortuous blood vessels also called vascular caverns lack muscular and elastic layers, and are filled by blood at different stages of thrombosis. Hemosiderin and gliosis often surround cavernomas. However, no neural tissue is present inside the lesion. Magnetic resonance images of cavernomas reveal a pathognomonic popcorn appearance produced by multiple small hemorrhages. Developmental venous anomalies are associated in around 30% of the cases. Cavernomas are very prevalent lesions ranging from 0.4 to 0.8% of the population. However, those located in the pineal region are very rare. Herein, we present the microsurgical treatment of a histologically confirmed cavernous malformation of the pineal region. Case description A 33-year-old patient with a pineal region cavernoma and progressive hydrocephalus underwent right supracerebellar infratentorial paramedian approach in a sitting praying position. The surgical planning did not require neuronavigation, but anatomical landmarks for the proper approach. Under high magnification, the pineal region was accessed over the superior cerebellar surface. After a focused lateral opening of the dorsal membrane of the Quadrigeminal Cistern, small vessels running in the posterior wall of the third ventricle were carefully dissected. A yellowish hemosiderin staining tissue allowed us to recognize the vicinity of the lesion. A small cottonoid delimitated the posterior border of the malformation, nonetheless, the superior limits underwent microdissection to release some cerebrospinal fluid from the third ventricle. A precise marginal dissection with bipolar forceps, microdissectors, and a thumb-regulated suction tube encircled the lesion. Gently traction of the lesion with ring microforceps associated further detachment of the cavernoma with the suction tube. Cotton dissection and water dissection technique were useful as well. A piecemeal resection, which is indicated in lesions with a deep and eloquent location, allowed us a complete removal of the cavernoma. Accurate hemostasis and continuous saline irrigation maintained a clean surgical field along the procedure. The gliotic tissue was left behind to prevent damage of the surrounding structures. Under endoscopic vision, remnants in the lower margins of the operative field were carefully evaluated. Finally, the surgical area was flushed with saline irrigation to detect any bleeding, and a small piece of tachosil was placed over the cavity. The postoperative course was uneventful. The hydrocephalus resolved after surgery and it did not require any further procedure. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author Juha Hernesniemi considers essential when performing an efficient and safe surgery for cavernous malformation of the pineal region. Videolink http://surgicalneurologyint.com/videogallery/iii-ventricle-cavernoma/.

  • unedited microneurosurgery of a mixed germ cell tumor of the pineal region
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Germ cell tumors comprise a heterogeneous group of neoplasms, classified as germinomas and nongerminomatous germ cell tumors based on clinicopathological features. The nongerminomatous group of tumors includes embryonal carcinoma, endodermal sinus tumor (yolk sac tumor), choriocarcinoma, mature and immature teratoma, and mixed germ cell tumors with more than one element. While germinomas are radiation-sensitive tumors, all other tumors have less response to radiotherapy, and it is suggested that gross total resection improves their overall survival and tumor-free survival rates. Herein, we present the microsurgical management of a histologically confirmed mixed-germ cell of the pineal region. Case description A patient with a mixed germ cell tumor underwent sitting praying position and midline supracerebellar infratentorial approach. After opening of the dura, a midline cerebellar vein was coagulated and cut, and the pineal region was accessed over the superior cerebellar surface. A tight reactive dorsal membrane of the Quadrigeminal Cistern was widely opened with subsequent evaluation of the neurovascular structures by intraoperative angiography. Under high microsurgical magnification between both basal veins, the dorsal wall of the fibrotic and solid tumor was coagulated and opened aiming an internal debulking of the lesion. Water dissection and cotton dissection were useful tools to separate the lateral borders of the tumor from the surroundings. Bipolar coagulation was helpful shrinking the tumor as well. The superior borders of the lesion, firmly attached to the roof of the third ventricle, required a careful evaluation. Ring microforceps in the right hand and thumb-regulated suction tube in the left one allowed us to pull out the tumor in a piece under soft and continuous traction with dissection of the cleavage plane. The superior attachment of the tumor was coagulated and cut. Finally, bipolar coagulation and small pieces of surgicel ensured a proper hemostasis. Postoperatively, the patient had a partial gaze palsy that improved gradually. The patient underwent adjuvant radiochemotherapy and currently is alive, free of tumor recurrence >12 years after surgery. Conclusion This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery for a mixed germ cell tumor. Videolink http://surgicalneurologyint.com/videogallery/pineal-tumor-5.

  • unedited microneurosurgery of a solitary fibrous tumor of the pineal region
    Surgical Neurology International, 2018
    Co-Authors: Joham Choquevelasquez, Juha Hernesniemi
    Abstract:

    Background Solitary fibrous tumor/hemangiopericytoma is a new combined entity introduced in the 2016 World Health Organization classification of tumors of the central nervous system for grade I-III soft-tissue tumors. While grades II and III present more aggressive course and might require adjuvant radiochemotherapy, grade I tumors have a good outcome after gross total resection. In this video-abstract, we present an unedited microneurosurgery of a histologically confirmed benign solitary fibrous tumor of the pineal region performed by a senior author (JH). Our aim is to demonstrate the efficiency and safety of our microsurgical technique into deep brain territories under the principle "simple, clean, and preserving the normal anatomy." For this, a paramedian supracerebellar infratentorial approach and a proper praying sitting position are essential. Case Description A patient with a history of slow progressive hydrocephalus was placed in a sitting praying position. The pineal region was accessed over the right cerebellar hemisphere following a right paramedian supracerebellar infratentorial approach. The lesion identified after a lateral opening of the Quadrigeminal Cistern followed partial debulking. Small vessels running on the surface of the tumor were coagulated and cut. After a careful dissection and devascularization of the lesion, the tumor was pulled out using long ring microforceps and long sharp bipolar forceps as well. The final steps included detachment of some tumoral remnants from the internal cerebral veins and meticulous attention to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful with only slight and occasionally double vision. The patient is alive and free of recurrence almost 4 years after surgery. Conclusion This unedited video offers all detailed aspects that a neurosurgeon like senior author JH considers essential when performing an efficient and safe surgery into the pineal region for this very rarely documented solitary fibrous tumor. Videolink http://surgicalneurologyint.com/videogallery/pineal-tumor.

Albert L Rhoton - One of the best experts on this subject based on the ideXlab platform.

  • midline and off midline infratentorial supracerebellar approaches to the pineal gland
    Journal of Neurosurgery, 2016
    Co-Authors: Satoshi Matsuo, Serhat Baydin, Abuzer Gungor, Koichi Miki, Noritaka Komune, Ryota Kurogi, Koji Iihara, Albert L Rhoton
    Abstract:

    OBJECTIVE A common approach to lesions of the pineal region is along the midline below the torcula. However, reports of how shifting the approach off midline affects the surgical exposure and relationships between the tributaries of the vein of Galen are limited. The purpose of this study is to examine the microsurgical and endoscopic anatomy of the pineal region as seen through the supracerebellar infratentorial approaches, including midline, paramedian, lateral, and far-lateral routes. METHODS The Quadrigeminal Cisterns of 8 formalin-fixed adult cadaveric heads were dissected and examined with the aid of a surgical microscope and straight endoscope. Twenty CT angiograms were examined to measure the depth of the pineal gland, slope of the tentorial surface of the cerebellum, and angle of approach to the pineal gland in each approach. RESULTS The midline supracerebellar route is the shortest and provides direct exposure of the pineal gland, although the culmen and inferior and superior vermian tributaries of the vein of Galen frequently block this exposure. The off-midline routes provide a surgical exposure that, although slightly deeper, may reduce the need for venous sacrifice at both the level of the veins from the superior cerebellar surface entering the tentorial sinuses and at the level of the tributaries of the vein of Galen in the Quadrigeminal Cistern, and require less cerebellar retraction. Shifting from midline to off-midline exposure also provides a better view of the cerebellomesencephalic fissure, collicular plate, and trochlear nerve than the midline approaches. Endoscopic assistance may aid exposure of the pineal gland while preserving the bridging veins. CONCLUSIONS Understanding the characteristics of different infratentorial routes to the pineal gland will aid in gaining a better view of the pineal gland and cerebellomesencephalic fissure and may reduce the need for venous sacrifice at the level of the tentorial sinuses draining the upper cerebellar surface and the tributaries of the vein of Galen.

  • microsurgical approaches to the perimesencephalic Cisterns and related segments of the posterior cerebral artery comparison using a novel application of image guidance
    Neurosurgery, 2004
    Co-Authors: Arthur J Ulm, Necmettin Tanriover, Masatou Kawashima, Alvaro Campero, Frank J Bova, Albert L Rhoton
    Abstract:

    Objective To describe the exposure obtained through six approaches to the perimesencephalic Cisterns with an emphasis on exposure of the posterior cerebral artery and its branches. Methods Dissections in 12 hemispheres exposed the crural, ambient, and Quadrigeminal Cisterns and related segments of the posterior cerebral artery. A Stealth Image Guidance workstation (Medtronic Surgical Navigation Technologies, Louisville, CO) was used to compare the approaches. Results The transsylvian approach exposed the interpeduncular and crural Cisterns. The subtemporal approach exposed the interpeduncular and crural Cisterns as well as the lower half of the ambient Cistern. Temporal lobe retraction and the position of the vein of Labbe limited exposure of the Quadrigeminal Cistern. Occipital transtentorial and infratentorial supracerebellar approaches exposed the Quadrigeminal and lower two-thirds of the ambient Cistern. Transchoroidal approaches exposed the posterior third of the crural Cistern, the upper two-thirds of the ambient Cistern, and the proximal Quadrigeminal Cistern. Transchoroidal approaches exposed the posterior portion of the P2 segment (P2p) in 9 of 10 hemispheres and were the only approaches that exposed the lateral posterior choroidal arteries and the plexal segment of the anterior choroidal artery. Occipital transtentorial and infratentorial supracerebellar approaches provided access to the P3 segment in all cases and exposed the P2p segment in 4 of 10 hemispheres. The subtemporal approach provided access to the Cisternal and crural segments of the anterior choroidal and medial posterior choroidal arteries and exposed the P2p segment in 3 of 10 hemispheres. Conclusion Surgical approaches to lesions of the perimesencephalic Cisterns must be tailored to the site of the pathological findings. The most challenging area to expose is the upper half of the ambient Cistern, particularly the P2p segment of the posterior cerebral artery.

  • management strategies for posterior cerebral artery aneurysms a proposed new surgical classification
    Acta Neurochirurgica, 1997
    Co-Authors: E R Seoane, Helder Tedeschi, E De Oliveira, M G Siqueira, G A Calderon, Albert L Rhoton
    Abstract:

    In a period of 10 years fifteen patients bearing sixteen aneurysms arising at the posterior cerebral artery were operated at our institution. Based on the approaches selected for each location a division of the posterior cerebral artery into three surgical segments is proposed. The first segment (S1), or anterior extends from the basilar artery bifurcation to the point where the artery reaches the level of the most lateral edge of the cerebral peduncle, the second segment (S2), or middle extends from the posterior limit of S1 to a point located just before the most medial extent of the artery in the Quadrigeminal Cistern (collicular point), and the third segment (S3), or posterior corresponds to the collicular point and to the portions of the posterior cerebral artery distal to it. Utilizing the concept of surgical segments all aneurysms in our series were satisfactorily exposed. Those arising at the S1 segment (8 cases) were operated either through a pterional or a pretemporal approaches; those from the S2 segment (6 cases) were operated either via the subtemporal or the subtemporal transventricular routes; and that arising from the S3 segment (1 case) was managed through the occipital interhemispheric approach. Among the aneurysms eleven were small, one was large, and four were large or giant. Ten of these aneurysms were surgically clipped, two coagulated, three treated by trapping and in one case the aneurysm was resected and the posterior cerebral artery was reconstructed by a termino-terminal anastomosis. The surgical results were considered good in all cases but one, where the patient died due to clinical complications three months after surgery. It is our belief that the use of this classification can provide the means to best select the most appropriate surgical approach to treat aneurysms arising at the posterior cerebral artery.

Juan Casado Pellejero - One of the best experts on this subject based on the ideXlab platform.

  • Quadrigeminal Cistern epidermoid cyst neuroendoscopy and endoscope assisted supracerebellar infratentorial approach
    World Neurosurgery, 2021
    Co-Authors: Laura Lopez B Lopez, Jesus Moles Herbera, Amanda Avedillo Ruidiaz, David Fustero De Miguel, Silvia Vazquez Sufuentes, Juan Casado Pellejero
    Abstract:

    The pineal region is a complex anatomical location with multiple surrounding important neurovascular structures.1,2 Several approaches to this region have been described, including posterior interhemispheric, transchoroidal, infratentorial supracerebellar, supracerebellar and infracerebellar trans-sinus, and their modifications. Neuroendoscopy and endoscope-assisted surgery have been widely applied to aid resection of pineal region lesions.3-5 A 40-year-old man presented with tonic-clonic seizures and bilateral papillary edema on fundus examination. Computed tomography showed a midline lesion at the level of the Quadrigeminal Cistern with mass effect on the aqueduct of Sylvius and posterior wall of the third ventricle, triggering obstructive triventricular hydrocephalus. As a first intervention, a third ventriculostomy was attempted unsuccessfully owing to unfavorable third ventricle floor anatomy. This approach was used to obtain a biopsy specimen, which showed an epidermoid cyst. Ventriculoscopy showed a communication of the pineal recess and Quadrigeminal Cistern owing to tumor invasion. An external ventricular drain was placed to control the hydrocephalus until complete resection was performed (Video 1). Several days later, tumor resection was carried out via the median supracerebellar infratentorial approach with the patient in semisitting position. After near-total resection under microscope, the third ventricle and both lateral recesses were explored with the endoscope. A small tumor remnant (visible only with endoscope) was identified and removed. This step was essential to achieve complete resection, confirmed by magnetic resonance imaging. The patient was discharged 6 days later without complications. During follow-up, the patient remains asymptomatic. The combination of microneurosurgery, neuroendoscopy, and endoscope-assisted surgery improves management of pineal region lesions and facilitates complete resection.

Francesco Magro - One of the best experts on this subject based on the ideXlab platform.

  • endoscopic treatment of Quadrigeminal Cistern arachnoid cysts
    Minimally Invasive Neurosurgery, 2005
    Co-Authors: M Gangemi, F Maiuri, Giuseppe Colella, Francesco Magro
    Abstract:

    Five patients with arachnoid cysts of the Quadrigeminal Cistern treated by endoscopic fenestration are reported and another eleven well-documented cases from the literature are reviewed. Among the five personal cases four were children and one was adult; the cyst fenestration was performed from the lateral ventricle in three cases and from the third ventricle in two. In four patients the endoscopic treatment resulted in clinical remission, whereas a two-month-old baby later required a shunt. The lateral ventricle-cystostomy and the third ventricle-cystostomy (according to the cyst extent) are the best endoscopic procedures, whereas the cyst fenestration through a suboccipital supracerebellar approach is no longer used. The rate of cured or improved patients after endoscopic surgery (14/16 or 87.5%) was rather similar to that of a group of twenty patients treated by traditional surgery (craniotomy and cyst excision and/or shunt) (85%). These data confirm that endoscopic fenestration of Quadrigeminal Cistern cysts must be performed as the first procedure because it is less invasive and avoids shunt dependency.