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Neuronavigation-guided endoscopy for intraventricular tumors in adult patients without hydrocephalus

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Intraventricular endoscopic operations are usually undertaken in patients with an enlarged ventricular system that provides good access to the ventricles, proper anatomic orientation and safety of maneuvers within the ventricles.

Aim: The preliminary assessment of the feasibility of endoscopic procedures in cases occurring without hydrocephalus.

Material and methods: Eleven patients with intraventricular tumor diagnosed in neuroimaging studies were included in the study. None of these cases was accompanied by hydrocephalus. Surgery was performed with a rigid neuroendoscope using a neuronavigation system. The purpose of the operation was tumor removal or histological verification.

Results: The colloid cyst of the third ventricle was removed in 5 patients. In 1 patient a glial-derived tumor adjacent to the interventricular foramen was partially resected. In 1 case a tumor of the lateral ventricle was totally removed, and in another case the resection of such a tumor was partial. In 2 cases, a biopsy of the tumor of the posterior portion of the third ventricle was undertaken, while in 1 case the biopsy was abandoned due to the risk of injury of structures surrounding interventricular foramen. There were no intraoperative or postoperative complications. None of the patients developed hydrocephalus in the long-term follow-up. The results of treatment in the study group did not differ from those obtained in patients operated on with hydrocephalus.

Conclusions: The presence of hydrocephalus is not necessary to perform endoscopic surgery. However, in each case it should be preceded by a thorough analysis of the feasibility of the endoscopic procedure and should be supported by a neuronavigation system.

No MeSH data available.


Related in: MedlinePlus

Planning station of neuronavigation system. Planning the optimal trajectory to access the tumor
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f0003: Planning station of neuronavigation system. Planning the optimal trajectory to access the tumor

Mentions: The purpose of the endoscopic procedure was tumor removal or histological verification. Furthermore, in patients with tumors located in the posterior part of the third ventricle third ventriculostomy was planned additionally. Prior to the surgery a thin layer (1–2 mm) head CT scan – reference study – was performed in all patients. It was loaded into the Medtronic S7 Stealth Station (planning station of neuronavigation system). All patients were operated on under general anesthesia. During the procedure the patient’s head was fixed to the operation table using a Mayfield clamp. Nine patients were operated on in the supine position with the head elevated to approximately 30°. In 2 cases of lateral ventricle tumors located near the occipital horn the patients were lying on their side with their head rotated in the direction opposite to the operation side. Based on the reference study an image of three basic planes (axial, sagittal, coronal) and a three-dimensional model were created. This allowed the burr hole location to be planned and the optimal access to the surgical target to be determined. The optical navigation enabled the spatial model of the navigation area to be built after registration of the patient position in relation to the planning station. This allowed for constant real-time surgical field tracking and its changes. Surgical instruments registered into the neuronavigation system were the standard ventricular drain and the endoscope sheath. The rigid Karl Storz neuroendoscopes were used: the GAAB model with Hopkins 0° optics (having the outer diameter of 6.5 mm and 3 mm working channel) and the FRAZEE model with Hopkins 6° optics (having the outer diameter of 8 mm and 5 mm working channel). The main advantage of the second one was the expanded toolkit. The intracranial access led through the burr hole marked by the navigation system and set in one line with the surgical target. When planning the access, eloquent areas of the brain were saved and the trajectory through the wider lateral ventricle was preferred. After dura incision and arachnoid coagulation the lateral ventricle was punctured according to the planned trajectory and the ventricular system was cannulated. Approximately 10 ml of Ringer’s solution was administered by a drain placed into the ventricle to broaden its diameter. At the same time, basic hemodynamic parameters (heart rate and blood pressure) were carefully monitored to prevent any increase of the intracranial pressure. Subsequently using the same trajectory the endoscopic sheath with an obturator was introduced, which was replaced in the next stage with the neuroendoscope. During the entire surgery, the operating field was rinsed with Ringer’s solution, maintaining constant filling of the ventricular system and transparency of the operating field. Once the tumor was located, the neuroendoscope was fixed in the holder. The feasibility of the intended procedure was analyzed first. It was based on the assessment of the tumor in relation to the vessels and surrounding structures. In the case of a lesion having the appearance of a colloid cyst the surface of the tumor was punctured with a needle and its contents were aspirated. Then the entrance point was widened with the grasping forceps, and in the cases of the presence of a solid part it was removed using the biopsy forceps. The remaining capsule was separated from the choroid plexus using the sharp instrument and bipolar coagulation. Then the capsule was totally removed or it was widely opened, coagulated and left if pushing the total removal carried the risk of bleeding. In solid tumors the operating strategy comprised coagulation of the superficial blood vessels using bipolar coagulation, incision and sampling of the tumor in order to perform the histopathological examination. After confirming the nature of the lesion, there followed tumor reduction by debulking from inside or the total removal of the tumor. During the procedure the tumor’s vessels were carefully coagulated, to prevent the bleeding that could limit the transparency of the operating field. Deep, uncontrolled penetration of the tumor within the biopsy forceps was avoided. The endoscopic biopsy was performed by taking samples from the parts of tumor presenting sparse vascularization. Efforts were made to collect the tumor samples that had not been the subject of earlier coagulation. In tumors of the posterior part of the third ventricle the biopsy was preceded by endoscopic third ventriculostomy. Hemostasis control and thorough ventricular system irrigation with warm (37ºC) Ringer solution ended the endoscopic part of the procedure. If the full transparency of cerebrospinal fluid (CSF) was not achieved, a drain was left in the lateral ventricle. After withdrawal of the neuroendoscope the hole in the dura was closed with TachoSil. The galea and the skin were tightly sutured. The ventricular system was rinsed with saline and the drain was removed on the first or second postoperative day (Photos 1 A–C, 2 A–C, 3–5).


Neuronavigation-guided endoscopy for intraventricular tumors in adult patients without hydrocephalus
Planning station of neuronavigation system. Planning the optimal trajectory to access the tumor
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5095270&req=5

f0003: Planning station of neuronavigation system. Planning the optimal trajectory to access the tumor
Mentions: The purpose of the endoscopic procedure was tumor removal or histological verification. Furthermore, in patients with tumors located in the posterior part of the third ventricle third ventriculostomy was planned additionally. Prior to the surgery a thin layer (1–2 mm) head CT scan – reference study – was performed in all patients. It was loaded into the Medtronic S7 Stealth Station (planning station of neuronavigation system). All patients were operated on under general anesthesia. During the procedure the patient’s head was fixed to the operation table using a Mayfield clamp. Nine patients were operated on in the supine position with the head elevated to approximately 30°. In 2 cases of lateral ventricle tumors located near the occipital horn the patients were lying on their side with their head rotated in the direction opposite to the operation side. Based on the reference study an image of three basic planes (axial, sagittal, coronal) and a three-dimensional model were created. This allowed the burr hole location to be planned and the optimal access to the surgical target to be determined. The optical navigation enabled the spatial model of the navigation area to be built after registration of the patient position in relation to the planning station. This allowed for constant real-time surgical field tracking and its changes. Surgical instruments registered into the neuronavigation system were the standard ventricular drain and the endoscope sheath. The rigid Karl Storz neuroendoscopes were used: the GAAB model with Hopkins 0° optics (having the outer diameter of 6.5 mm and 3 mm working channel) and the FRAZEE model with Hopkins 6° optics (having the outer diameter of 8 mm and 5 mm working channel). The main advantage of the second one was the expanded toolkit. The intracranial access led through the burr hole marked by the navigation system and set in one line with the surgical target. When planning the access, eloquent areas of the brain were saved and the trajectory through the wider lateral ventricle was preferred. After dura incision and arachnoid coagulation the lateral ventricle was punctured according to the planned trajectory and the ventricular system was cannulated. Approximately 10 ml of Ringer’s solution was administered by a drain placed into the ventricle to broaden its diameter. At the same time, basic hemodynamic parameters (heart rate and blood pressure) were carefully monitored to prevent any increase of the intracranial pressure. Subsequently using the same trajectory the endoscopic sheath with an obturator was introduced, which was replaced in the next stage with the neuroendoscope. During the entire surgery, the operating field was rinsed with Ringer’s solution, maintaining constant filling of the ventricular system and transparency of the operating field. Once the tumor was located, the neuroendoscope was fixed in the holder. The feasibility of the intended procedure was analyzed first. It was based on the assessment of the tumor in relation to the vessels and surrounding structures. In the case of a lesion having the appearance of a colloid cyst the surface of the tumor was punctured with a needle and its contents were aspirated. Then the entrance point was widened with the grasping forceps, and in the cases of the presence of a solid part it was removed using the biopsy forceps. The remaining capsule was separated from the choroid plexus using the sharp instrument and bipolar coagulation. Then the capsule was totally removed or it was widely opened, coagulated and left if pushing the total removal carried the risk of bleeding. In solid tumors the operating strategy comprised coagulation of the superficial blood vessels using bipolar coagulation, incision and sampling of the tumor in order to perform the histopathological examination. After confirming the nature of the lesion, there followed tumor reduction by debulking from inside or the total removal of the tumor. During the procedure the tumor’s vessels were carefully coagulated, to prevent the bleeding that could limit the transparency of the operating field. Deep, uncontrolled penetration of the tumor within the biopsy forceps was avoided. The endoscopic biopsy was performed by taking samples from the parts of tumor presenting sparse vascularization. Efforts were made to collect the tumor samples that had not been the subject of earlier coagulation. In tumors of the posterior part of the third ventricle the biopsy was preceded by endoscopic third ventriculostomy. Hemostasis control and thorough ventricular system irrigation with warm (37ºC) Ringer solution ended the endoscopic part of the procedure. If the full transparency of cerebrospinal fluid (CSF) was not achieved, a drain was left in the lateral ventricle. After withdrawal of the neuroendoscope the hole in the dura was closed with TachoSil. The galea and the skin were tightly sutured. The ventricular system was rinsed with saline and the drain was removed on the first or second postoperative day (Photos 1 A–C, 2 A–C, 3–5).

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Intraventricular endoscopic operations are usually undertaken in patients with an enlarged ventricular system that provides good access to the ventricles, proper anatomic orientation and safety of maneuvers within the ventricles.

Aim: The preliminary assessment of the feasibility of endoscopic procedures in cases occurring without hydrocephalus.

Material and methods: Eleven patients with intraventricular tumor diagnosed in neuroimaging studies were included in the study. None of these cases was accompanied by hydrocephalus. Surgery was performed with a rigid neuroendoscope using a neuronavigation system. The purpose of the operation was tumor removal or histological verification.

Results: The colloid cyst of the third ventricle was removed in 5 patients. In 1 patient a glial-derived tumor adjacent to the interventricular foramen was partially resected. In 1 case a tumor of the lateral ventricle was totally removed, and in another case the resection of such a tumor was partial. In 2 cases, a biopsy of the tumor of the posterior portion of the third ventricle was undertaken, while in 1 case the biopsy was abandoned due to the risk of injury of structures surrounding interventricular foramen. There were no intraoperative or postoperative complications. None of the patients developed hydrocephalus in the long-term follow-up. The results of treatment in the study group did not differ from those obtained in patients operated on with hydrocephalus.

Conclusions: The presence of hydrocephalus is not necessary to perform endoscopic surgery. However, in each case it should be preceded by a thorough analysis of the feasibility of the endoscopic procedure and should be supported by a neuronavigation system.

No MeSH data available.


Related in: MedlinePlus