Endoscopic Approach for Management of Colloid Cyst

INTRODUCTION

More than half of individuals with third ventricle colloid cysts present with symptoms at the time of identification and eventually need neurosurgical treatment. Without regard to gender, they were often diagnosed between the second and fifth decades of life, and the median diameter of symptomatic tumors was around 12 mm.¹

Most of these individuals exhibit hydrocephalus symptoms, such as headache, vomiting, impaired vision, gait ataxia, and a deterioration in cognitive abilities. A tiny percentage of individuals with symptoms have acute obstructive hydrocephalus, which may develop into sudden death.²

In particular, for asymptomatic individuals with accidentally detected lesions who are frequently lost to follow-up, attempts to build evidence-based prognostic variables and surgical indications have been hampered due to poor knowledge of the natural history of colloid cysts. Patients with lesions smaller than 1 cm in size often get repeated imaging and observation, but those with bigger or symptomatic lesions have surgery.²

 On a computed tomography (CT) scan, colloid cysts are often homogeneously hyperdense as compared to the brain. Tumors are frequently hyperintense on T1-weighted sequences of magnetic resonance imaging (MRI) and hypointense on T2-weighted sequences.³

Recently, several researchers have come to the conclusion that the endoscopic method of removing colloid cysts is less intrusive than conventional microsurgical methods and may reduce morbidity and postoperative consequences, including decreased rates of infection, infarct, and seizure. Additionally, the rate of shunt reliance has fallen statistically significantly.⁴

The inability to conduct bimanual micro dissecting of the cyst wall from the important structures is one of the main criticisms of the typical single-burr hole endoscopic procedure. This method depends on cyst wall suction followed by coagulation of the leftover cyst wall remnants. The likelihood of a subsequent recurrence is increased by the existence of remaining cyst wall. While endoscopic studies have reported shorter hospital stays and lower complication rates, microsurgical series have traditionally shown greater rates of full resection. ⁵

The aim of the work was to assessment of the efficacy of endoscopic excision of the colloid cyst in relation to the size of cyst.

PATIENTS AND METHODS

The research was prospectively carried out at the neurosurgery department of Al-Azhar university hospitals, from January 2019 to December 2021. included fifteen patients with colloid cyst and they were operated by endoscope for their mass and hydrocephalus.

Preoperatively, all patients were subjected to:

History taking: Personal history:Name, age, sex, profession, place of residence, marital status, any unusual habits of medical significance, and the patient's complaints in their own words. In addition to other complaints related to the patient's symptoms, the complaint presented was the one that caused the patient the greatest discomfort, present history: concentrating on examination of the patient's symptomatology, particularly its onset, progression, and persistence. The patient was asked about other neurological symptoms if not mentioned, including symptoms of increased ICP as headache, nausea, vomiting, and visual symptoms, e.g., blurring of vision, symptoms of cranial nerve affection, sensory or motor affection, gait and balance disturbance, sphincteric disturbance, seizures, attacks of loss of consciousness, and memory deficit, past history: including allergies, past radiation exposure, previous surgeries, drugs used, and any related medical conditions such diabetes and high blood pressure and family history: including history of diabetes, hypertension, tumors and similar conditions among family members, and positive consanguinity.

Clinical examination: General examination: complete general examination was applied for every case including the patient's skeletal and urogenital systems, length, weight, head, neck, chest, and belly, as well as their vital signs and neurological examination: A fully detailed and thorough neurological examination was performed for every case, including:

Conscious level assessment by GCS, general intellectual functions including orientation, general fund of knowledge, and global attention, memory and affect, cranial nerves with special attention to optic nerve by visual acuity, field of vision and fundus, motor system including state of muscles, tone, and motor power, reflexes, including superficial and deep reflexes, sphincters, sensory system including superficial, deep and cortical sensations and gait and coordination.

Investigations: standardized laboratory tests: including PT, PC, INR, serum sodium and potassium, CBC, blood sugar, hepatic and renal functions tests, and blood sugar. ECG was done for all patients more than 40 years of age and radiological investigations: all patients had preoperative plain and postcontrast CT scans as well as MRI with contrast of the brain. CT scans were used primarily to show the hydrocephalic changes, presence of calcified or hemorrhagic areas. MRI of the brain with contrast was done to show the exact site, size, and enhancement of the lesion to differentiate from other lesions of the third ventricle, and for planning of the management. MRI included T1W, T2W, and T1W with contrast, and FLAIR sequences obtained in axial, coronal and sagittal planes. Typically, axial views are used to quantify cyst size.

Inclusion criteria: Patients with large colloid cysts of thirdventricle (1 cm or more in diameter) or smaller symptomatic cysts, age range 12 – 65 years and patients fit for general anesthesia.

Exclusion criteria: Patients under the age of 12 and over the age of 65, those with small, asymptomatic third ventricle colloid cysts, those with radiologically solid colloid cysts, those with colloid cysts outside the third ventricle, those who refuse surgery or are medically unfit for surgery, and those with other third ventricle lesions.

Operative procedures: A right frontal linear or semilunar skin incision was made over Kocher's point, 3 cm lateral from midline, immediately anterior to the coronal suture, while the patient was under general anesthesia, reclined, and had his or her head raised 30 degrees. A 1.5-cm burr hole was done at Kocher’s point and a cruciate dural incision was made. After bipolar cauterization of the cortical surface and vessels, the endoscope was introduced into the ventricular system.

The relationship between the anatomical landmarks and the colloid cyst was determined after comprehensive endoscopic evaluation of the anatomical structures and foramen of Monro landmarks. Bipolar coagulation of the cyst capsule and the choroid plexus above it was used as the first step in the resection of the cyst, which was then followed by the fenestration of the capsule.

Suction of the contents was tried after inserting a central venous cannula. After the cyst's entire contents were removed, bipolar shrinking of the cyst capsule's inner and outer surfaces enabled maximal resection.

The endoscope was withdrawn after making sure that there was no intraventricular bleeding. EVD was placed in 3 patients. Gel foam was used to plug the site of the corticectomy and to cover the burr hole, followed by galeal and skin closure

Postoperative management: Prior to being moved to the normal patients' ward, all patients had at least the first 24 hours of postoperative monitoring in an intensive care unit (ICU). All patients were treated during the postoperative hospital stay by prophylactic broad-spectrum antibiotics, anti-epileptics, and dehydrating measures, in addition to analgesics, antipyretics and antiemetic as needed. Routine postoperative laboratory investigations were done for all patients including CBC, liver and renal functions, and serum electrolytes.

A thorough and in-depth postoperative neurological clinical examination was performed on each patient.

The patients were monitored in the early postoperative period for manifestations of increased ICP, and for possible postoperative complications.

In patients with EVDs, the EVD was initially left open at 15 cm H2O and monitored for amount and color of fluid. Weaning of EVD was usually tried on the third day as long as the CSF was clear. The patient was carefully watched for symptoms of elevated ICP, such as headache, nausea, and vomiting, and the EVD was closed for 24 hours after that. Subsequently, a brain CT scan was done to make sure that the ventricles had not enlarged, and the EVD was then taken out. When there were signs of hydrocephalus, the patient was operated upon for V-P shunt insertion.

Postoperative radiology: All patients were subjected to control plain and postcontrast CT scans of the brain in the first 48 hours postoperatively to evaluate extent of tumor resection, size of ventricles, periventricular CSF permeation, and cortical effacement. Another brain CT scan was done 24 hours after closure of EVD before its removal, then another CT scan 1 – 2 days after removal of EVD. Serial CT scans of the brain were done during the postoperative hospital stay until the patient was discharged for exclusion of hydrocephalus. MRI of the brain with contrast was done 1 month after surgery to detect any cyst remnants.

Patient discharge and follow-ups: Patients were kept in the hospital until they were stable enough for discharge. Then, at intervals of one week, one month, three months, and six months, all patients were followed up in the outpatient clinic.

Outcome measures:

Patient’s outcome was assessed according to: Extent of tumor resection: evaluated by postoperative plain and postcontrast CT scans of the brain in the first 48 hours, and follow-up MRI done after 1 month. Resection is called “gross total resection” when there are no obvious remnants of colloid cyst visible on postoperative brain scans. If a portion of the cyst can still be seen on a postoperative brain scan, it is called a “subtotal resection.” And improvement of symptoms: including headache, nausea and vomiting, attacks of loss of consciousness, visual symptoms including blurring of vision, diminution of vision and diplopia, gait disturbance, urinary incontinence, memory deficit, motor deficit, dizziness, seizures, and DCL. The postoperative improvement of symptoms was assessed in the 6 months period of follow-up.

Postoperative complications: including persistent hydrocephalus requiring V-P shunting, intraventricular hemorrhage, intracerebral hematoma, subdural hematoma, subdural hygroma, arterial infarction, venous infarction, mutism, memory deficit, hemiparesis/hemiplegia, CSF leak, seizures, ventriculitis, meningitis, wound infection, and death.

RESULTS

Quantitative data represented as (mean ± SD) or median (min-max), Categorical data represented as Number (%)

Table 1: Demographic data in the study cases

Categorical data expressed as Number (%)

Table 2: Analysis of the presenting symptoms in the study cases

Categorical data expressed as Number (%)

Table 3: Analysis of the signs in the study cases

Categorical data expressed as Number (%)

Table 4: Analysis of preoperative data in the study cases

Categorical data expressed as Number (%)

Table 5: Analysis of preoperative radiological data in the study cases

Categorical data expressed as Number (%)

Table 6: Analysis of surgical data in the study cases

P: probability.

Quantitative data are expressed as mean ± SD (range)

T: Paired samples t-test

Table 7: Correlation between extent of resection and diameter of the cyst

Case 1

History: 28 years old male patient, complaining of dull-aching bifrontal headache for 2 months of gradual onset and progressive course. The patient also developed blurring of vision 1.5 month prior to admission of gradual onset and progressive course.

Examination: GCS 15 and Bilateral papilledema G3.

Imaging: CT showed hyperdense well-circumscribed circular mass in the third ventricle with no contrast enhancement, and hydrocephalus and MRI showed isointense circular third ventricular mass in T1W sequence, and hyperintense in T2W sequence, measuring 25 mm in diameter, with no contrast enhancement.

Management: Endoscopic approach, no EVD was inserted and ETV was done.

Postoperatively: All symptoms improved, no complications, follow-up CT and MRI showed GTR of the cyst and the patient was discharged 6 days after surgery with excellent outcome.

Fig. 1: Preoperative brain CT scan showing hyperdense colloid cyst in the third ventricle and hydrocephalus.

Fig. 2: Postoperative brain CT scan showing GTR of colloid cyst and normal-sized ventricles

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Fig. 3: Preoperative MRI of the brain showing isointense colloid cyst in the third ventricle in T1W sequence (A) and hyperintense in T2W sequence (B)

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Fig. 4: Postoperative MRI of the brain done after 1 month of surgery showing GTR of the colloid cyst in axial T1W (A) and T2W (B) sequences

Case 2

History: 27 years old male patient, complaining of bifrontal headache for 3 months of acute onset and intermittent course, associated with nausea and vomiting. The patient also developed blurring and diminution of vision, more in the left eye, for 1.5 month of gradual onset and progressive course.

Examination: GCS 15, visual acuity in right eye 6/12, and in left eye 6/36 and bilateral papilledema G3.

Imaging: CT showed hyperdense round mass in the third ventricle with no contrast enhancement, and hydrocephalus and MRI showed isointense circular mass in the roof of the third ventricle in T1W sequence, and hypointense in T2W sequence, measuring about 11 mm in diameter, with no contrast enhancement.

Management: Endoscopic approach, EVD was inserted after cyst resection.

Postoperatively: All symptoms improved, no complications, follow-up CT and MRI showed small cyst remnants, EVD was removed 4 days postoperatively and the patient was discharged 12 days after surgery with good outcome.

Fig. 5: Preoperative brain CT scan showing hyperdense third ventricular colloid cyst and hydrocephalus.

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Fig. 6: Postoperative brain CT scan done 1 day after surgery showing small hyperdense colloid cyst remnant, pneumocephalus and EVD

Fig 7: Brain CT scan done 24 hours after closure of EVD showing normal-sized ventricles

Fig. 8: Follow-up brain CT scan done after removal of EVD showing small cyst remnant, and normal-sized Ventricles

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Fig. 9: Preoperative MRI of the brain showing colloid cyst of the third ventricle, isointense in axial T1W (A) and hypointense in T2W sequence (B)

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Fig. 10: Postoperative MRI of the brain done after 1 month of surgery showing small isointense cyst remnant in axial T1W sequence (A) hypointense cyst remnant in axial T2W sequence (B).