Factors predicting successful stereotactic aspiration of colloid cysts.

Stereotactic aspiration is a valuable surgical alternative for colloid cysts, but due to cyst heterogeneity, it is not uniformly successful as the sole treatment in all patients. Since 1981, we performed CT-guided stereotactic aspiration as the initial procedure in 25 patients with colloid cysts. We retrospectively reviewed our experience in the first 22 patients and found that preoperative CT imaging studies accurately determined size and predicted cyst viscosity. The preoperative CT appearance of a hypodense or isodense cyst correlated favorably with successful aspiration. Preoperative MRI provided excellent anatomic definition of the cyst and its relationship to other structures, but failed to correlate successful aspiration. Unsuccessful aspiration was related to the high viscosity of the intracystic material or deviation of the cyst away from the aspiration probe. These factors were used prospectively in 3 additional patients to accurately predict success of cyst aspiration.     

Changing concepts in the treatment of colloid cysts. An 11-year experience in the CT era

Since computerized tomography (CT) scanning became available at the University Health Center of Pittsburgh in July, 1975, 17 patients have undergone removal of colloid cysts of the third ventricle by transfrontal, transcallosal, or stereotaxic surgery. All patients presented with symptoms and signs of increased intracranial pressure; CT scanning proved to be the best neurodiagnostic test to define the colloid cysts. Since the development of CT-guided stereotaxic surgery, the authors have preferentially performed stereotaxic aspiration in seven patients; three of these subsequently required craniotomies to remove residual cysts producing persistent symptoms. The viscosity of the intracystic colloid material and/or displacement of the cyst away from the aspiration needle were reasons for unsuccessful aspiration; the CT appearance did not correlate with the ability to aspirate the lesion by the sterotaxic technique. Postoperative patency of the ventricular system was documented by intraoperative CT ventriculography performed during stereotaxic surgery. Removal of the cyst wall was not necessary. Because of the low associated morbidity rate, percutaneous stereotaxic aspiration is recommended as the initial treatment of choice for colloid cysts of the third ventricle. If stereotaxic aspiration fails and symptoms persist, craniotomy should be performed.     

Stereotactic cyst wall disruption and aspiration of colloid cysts of the third ventricle.

BACKGROUND: Current strategies of surgical therapy for colloid cysts have been associated with low rates of initial success and high rates of morbidity, mortality and recurrence of cysts. Cyst recurrence following simple stereotactic aspiration has been hypothesized to be due to regrowth of the epithelium composing the cyst wall. METHODS: We propose a procedure involving stereotactic disruption of the colloid cyst wall with the removal of a portion of the cyst wall followed by aspiration of cyst contents as a surgical therapy for colloid cysts. RESULTS: This procedure was performed in 2 female and 3 male patients who were followed for an average of 49 months with all patients demonstrating immediate improvement of symptoms and resolution of the cyst verified with repeat computerized tomography (CT) scans. There was one incidence of recurrence in an asymptomatic patient at 75 months postoperatively. CONCLUSION: We propose that stereotactic partial cyst wall disruption and content aspiration may limit recurrence of colloid cysts, thus offering an advantage over simple stereotactic aspiration alone.     

Colloid cysts: experience with the management of 84 cases since the introduction of computed tomography

A retrospective review of colloid cysts diagnosed from 1974 to 1986 emphasizes the presenting symptoms of these lesions, their surgical management, and the contribution of modern imaging techniques to their diagnosis and therapy. In this 12-year period, 84 patients (45 men and 39 women) had a colloid cyst diagnosed. The patients' mean age was 46 years (range, 7-82 years). Surgery was performed in 55 patients, 7 of whom had undergone prior surgery elsewhere. The surgical approaches used were transfrontal-transventricular, transcallosal, computer-assisted stereotactic aspiration and resection by stereotactic craniotomy, and shunting of cerebrospinal fluid without removal of the lesion. There was no operative mortality, but complications occurred in 15 patients (27%). Preoperative imaging showed hydrocephalus in 93% of the patients: severe in 43%, moderate in 36%, and mild in 14%. In the surgically treated group, the most common presenting symptoms were headache, change in mental status, ataxia, nausea and vomiting, visual disturbance, emotional lability/inappropriate affect, depersonalization, and hypersomnolence. Twenty-four patients for whom surgery was not recommended are being followed up closely. Most of these patients had normal ventricles. The symptoms in this group included headache, anxiety/nervousness, ataxia, memory impairment, visual disturbance, and seizures. Five autopsy cases of patients with colloid cysts were available during this period and were reviewed. Direct removal of colloid cysts can be accomplished with low morbidity and mortality, avoiding the frequent revisions and complications related to shunt procedures. There is a subgroup of colloid cysts that can be operated upon electively or followed up closely with serial imaging studies.     

Endoscope-assisted removal of colloid cysts of the third ventricle

Colloid cysts are benign space-occuping lesions, which arise from the velum interpositum or the choroid plexus of the third ventricle and are able to produce symptomatic obstruction of the foramina of Monro with resultant hydrocephalus. In our department, we have operated on colloid cysts routinely in an endoscope-assisted microsurgical manner via a key–hole approach. During a period of 10 years, 28 microsurgical resections of colloid cysts of the third ventricle were performed. Seven patients demonstrated colloid cysts inside the third ventricle with obstruction of the right foramen Monro, two patients demonstrated cysts with obstruction of the left foramen Monro. Twelve patients suffered from cysts inside the third ventricle with obstruction of both foramina Monro and five patients demonstrated cysts lying into the third ventricle without obstruction of the foramina. In 21 patients no preoperative therapy was performed outside. Three patients had received shunt systems before in other hospitals, two patients received aspiration of the cysts under stereotactic conditions and two patients received external ventricular drains. Total removal of the cyst was achieved in all patients (100%). No patient received a second operation, because none had a recurrent cyst. All cysts were removed with the cyst wall. Overall clinical improvement was achieved in a long-standing period between 6 and 83 months in 27 (96%) patients. In one patient (4%) the psychomotor disturbance was unchanged and no patient deteriorated. From the microsurgical point of view, the combination of keyhole surgery under endoscopic visual control using preexisting anatomical windows offers an effective minimally invasive approach.     

Stereotactic endoscopic treatment of colloid cysts of the third ventricle

Summary In order to avoid invasive procedures (transfrontal, transcallosal) in the surgical treatment of colloid cysts the stereotactic aspiration technique was introduced by Bosch, RÄhn and Backlund in 1978. The viscosity of the intracystic colloid and the displacement of the cyst away from the aspiration needle are possible reasons for unsuccessful aspiration. GT-guided stereotactic endoscopic technique gives the opportunity to fenestrate the cyst wall under direct visual control.After CT-guided stereotactic puncture of the right lateral ventricle with the foramen of Monro as target a steerable endoscope is introduced and the foramen of Monro is passed. The wall of the cyst is fenestrated and coagulated by means of monopolar (or laser) coagulation.Using this technique we have treated four patients with colloid cysts. Immediately postoperatively all of them were relieved of their complaints and have been symptomfree for a mean follow up period of twelve months. Studies of cerebrospinal fluid flow patterns, performed prior to and every six months after the endoscopic intervention, confirmed a remarkable reduction of foraminal obstruction.     

Treatment of colloid cysts of the third ventricle by stereotaxic microsurgical laser craniotomy

The therapeutic strategies employed in the management of anterior third-ventricular mass lesions remain controversial. Resection by conventional craniotomy, whether via a transcallosal or transcortical approach, carries well-known risks and limitations. Alternatively, in this region traditional stereotaxy has been relegated to use with biopsy only or cyst aspiration procedures. Combining aspects of both conventional and stereotaxic techniques has allowed total removal of 12 colloid cysts in six women and six men ranging in age from 25 to 71 years. No mortality and minimal morbidity have been associated with the procedures. There has been no evidence of recurrence in an average follow-up period of 19 months. By coupling the benefits of stereotaxic precision and localization to the microsurgical management of colloid cysts, several rewards have been realized: 1) only a limited cortical dissection is needed; 2) the hazards of callosal or forniceal injury can be avoided; 3) the lesion is easily localized regardless of ventricular size; 4) hemostasis can be readily achieved with bipolar cautery or defocused laser power; and 5) most importantly, a total resection is possible with little risk to the patient. Stereotaxic microsurgical laser craniotomy provides a new option for the management of colloid cysts and other anterior third-ventricular lesions.     

Endoscopic treatment of colloid cysts of the third ventricle: 9 consecutive cases.

The purpose of this study is to evaluate the efficacy of the endoscopic technique for the treatment of the colloid cysts of the third ventricle. Between August 1995 and October 1997 a series of nine patients with colloid cyst of the third ventricle (6 males and 3 females) were treated with this method. The technique, consisting of cyst fenestration, aspiration of the colloid, and coagulation of the internal layer of the wall, was always effective in restoring CSF circulation. Operating time was 54-120 min (median 67 min). We recorded only one post-operative septic complication but no signs of direct surgical morbidity. Post-operation hospital stay was 2-30 days (median 5 days). Follow up was 14-40 months (mean 27 months). We did not observe any clinical or radiological recurrence. Endoscopic treatment of colloid cysts of the third ventricle is a safe and effective alternative to the well-established approaches of microsurgical removal and stereotactic aspiration. Only a very long follow-up will answer the question of the long-term effectiveness of this method.     

Interhemispheric transcallosal subchoroidal fornix-sparing craniotomy for total resection of colloid cysts of the third ventricle

OBJECT: Endoscopic surgery has been reported to be more cost-effective and safer than open craniotomy for resection of colloid cysts, despite a 5-10% conversion rate to craniotomy, a 5% recurrence rate, a 5-10% ventricular shunting rate, a 5-10% epilepsy rate, and a 3-4 day hospital stay. In 1985, the authors developed a interhemispheric, transcallosal, subchoroidal, fornix-sparing approach that allowed safe total resection of the colloid cyst and that appeared to be superior to the endoscopic approach. The long-term results are analyzed and compared with findings in the literature. METHODS: Fifty-seven consecutive colloid cysts were totally removed via a 3 x3-in paramedian craniotomy flap and a microscopic interhemispheric, transcallosal, subchoroidal approach sparing the ipsilateral fornix. The length of the callosotomy was 1.5-2 cm in all patients. The mean follow-up duration was 12 years (range 2-22 years). A retrospective analysis comparing the authors' results with those reported in the endoscopic literature was performed. RESULTS: All patients had 1-year postoperative imaging studies (CT or MR imaging) documenting gross-total resection with no deaths, infection, hemiparesis, seizures, or disconnection syndrome. One surgery was complicated by bilateral subdural hematomas, which were successfully treated. There has been a zero recurrence rate. Three patients required a permanent ventriculoperitoneal shunt (including 2 who required emergency ventriculostomy before surgery). The mean hospital stay was 4.8 days (range 2-24 days). There was 1 patient with permanent short-term memory loss who presented with a herniation syndrome requiring emergency ventriculostomy. CONCLUSIONS: The interhemispheric, transcallosal, subchoroidal, fornix-sparing approach to gross-total resection of colloid cysts is safe and led to a zero recurrence rate with no permanent neurological sequelae including epilepsy, and these results are superior to any reported results with endoscopy.     

Stereotactically guided microsurgical removal of colloid cysts

Summary. Background. The surgical technique and clinical results for a series of 16 consecutive patients who underwent resection of third ventricular colloid cysts through a stereotactically guided cylindrical retractor are presented.Methods. Between March 1993 and December 2002, 16 patients, 11 males and 5 females with a mean age of 36, were admitted with colloid cysts of the third ventricle. Four patients had undergone previous surgery, of which two were simple aspirations, one endoscopic aspiration, and one transcallosal partial removal. Four patients required emergency ventriculostomies on admission. In all patients the foramen of Monro was targeted using a Leksell stereotactic frame. A coronal craniotomy three to four cm in diameter was performed and a cylindrical retractor 14mm in diameter was advanced to the target. Microsurgical removal of the cyst was then performed through the retractor.Findings. Total removal of the cyst was achieved in all cases. Median follow-up time is 42 months. Complete resolution of symptoms occured in all patients. Control magnetic resonance imaging revealed no residual cysts. All patients have returned to their previous occupations without sequelae or epilepsy.Conclusion. The outcome obtained in this series has shown that transfrontal transforaminal total removal of colloid cysts through a stereotactically guided cylindrical retractor is a safe procedure.     

Colloid cysts of the third cerebral ventricle. Computed x-ray tomography, MRI and stereotaxic puncture. Apropos of 9 cases

The authors report their experience with Colloid Cysts of the third ventricle (9 cases treated between 1983 and 1989). Eight of them were punctured using stereotactic approach; five cysts were completely evacuated and the patients are free of recurrence. In three cases, tapping was impossible or the cyst insufficiently evacuated and the patients were secondary operated on (open microsurgical approach). The last case was directly operated on. Colloid cysts cured by stereotactic puncture were all hypo or iso-dense at C.T. scan and had a diameter of more than 1 cm. All these cases have had a M.R.I. exploration and the image of the cyst was always the same increased T1 and T2 signal. Unfortunately, we did not have the opportunity to realize M.R.I. in colloid cysts of a small size and hyperdense at C.T. scan. These results can help to the indication of a stereotactic puncture at the first attempt in some well defined colloid cysts.     

Initial experience related to the use of the Cosman-Roberts-Wells stereotactic instrument. Technical note

Initial experience with a new arc-radius design of stereotactic frame that interfaced with the existing components of the Brown-Roberts-Wells instrument is reported. Over a 6-month period, 32 procedures were performed on 23 males and nine female patients (mean age 32 years); these included 27 stereotactic biopsy procedures, two stereotactic implantations of cyst catheter reservoirs, two ventriculoscopic aspirations of third ventricular colloid cysts, and one stereotactic aspiration of a craniopharyngioma. In all cases successful targeting was achieved and verified by postoperative computerized tomography. There were no operation-related complications. This new frame offers rapid and accurate targeting and is a useful adjunct to the stereotactic armamentarium.     

Stereotactic craniotomy in the resection of small arteriovenous malformations

Surgical resection of 10 obscure arteriovenous malformations (AVM's) was accomplished with craniotomy guided by computerized tomography (CT) or angiography and the use of the Brown-Roberts-Wells stereotactic frame. Stereotactic craniotomy was invaluable for resection of the following types of AVM's: 1) AVM's with a nidus less than 2 cm in diameter, 2) AVM's located in an eloquent area of the brain, and 3) AVM's located deep in the brain. Stereotactic localization of these AVM's on preoperative radiological studies provides a precise route to the nidus, often avoiding important areas of the brain. This series included six male and four female patients with a mean age of 32 years. All patients presented with an intracerebral hemorrhage, from which eight made a complete neurological recovery prior to surgery. Two AVM's were located on the cortex, three were found subcortically, and five were situated near the ventricles or in the deep white matter. As a guide, angiography was used in six cases and CT in four cases. In each instance, the study providing the best image of the AVM nidus was employed. Postoperatively, no neurological deficits were found in eight patients and, in the two patients with preoperative deficits, neurological improvement was observed after recovery from surgery. Postoperative studies revealed complete removal of the AVM in all patients, and all lesions were confirmed histologically. The authors conclude that stereotactic craniotomy provides the optimum operative approach for the localization and microsurgical resection of AVM's that are either obscure or located deep in the brain.     

Assessment of memory and new learning ability following stereotaxy-guided transcortical resection of anterior third ventricular colloid cysts

In a prospective study, memory and new learning ability functions were assessed pre-operatively (17 patients) and in the early post-operative period (22 patients) at 7-26 days following surgery in patients undergoing stereotactic transcortical excision of their colloid cysts. Pre-operative assessment detected impaired memory in 5 patients, 2 of whom had no memory-related complaints. Impaired new learning ability was detected pre-operatively in 7 patients. There was a statistically non-significant trend towards improvement in the dysfunction scores post-operatively in most patients. No correlation was detected between the cyst size, presence of raised intracranial pressure at presentation, hydrocephalus and the pre-operative dysfunction scores. Stereotactic transcortical resection of colloid cysts does not impair these functions in the majority of patients and might improve these functions in some. In the absence of clinical or radiological predictors of dysfunction of memory and new learning ability, pre-operative neuropsychological assessment has a role in detecting impaired memory and new learning ability in patients with anterior third ventricular colloid cysts who may not even complain of them.     

Colloid cysts — a review including 19 own cases

Between 1974 and 1987 19 patients harbouring colloid cysts of the third ventricle have been treated in our department. There were 12 male and 7 female patients with an average age of 34 years (ranging from 17 to 58). Eighteen of the 19 patients underwent direct microsurgical removal of the space occupying lesion using the transcortical-transventricular approach. One patient had placement of a ventriculoperitoneal shunt and declined further treatment. There were no deaths in the entire series and no permanent neurological deficits were observed postoperatively. Surgery was successful in unblocking CSF pathways in 12 patients; six patients required permanent CSF diversion. Considering the advantages and disadvantages of various surgical modalities for the treatment of the lesions we recommend the microsurgical removal of the colloid cyst using the transcortical-transventricular approach.     

CT-assisted stereotaxic aspiration of colloid cysts of the third ventricle

A technique is reported for the stereotaxic evacuation of colloid cysts of the third ventricle using a stereotaxic system adapted for computerized tomography (CT) scanning. This is an accurate, simple, and reproducible method that avoids the risks of direct approaches. Successful intracystic aspiration resulting in the cure of the patient may be difficult when the viscosity of the cyst contents is high. Thus, the authors use a large cannula (1.8 mm in inner diameter) to evacuate cysts that appear hyperdense on CT scans; these seem to contain a thicker colloid material than hypodense or isodense cysts.     

Endoscopic treatment of prepontine arachnoid cysts

Prepontine (or suprasellar) arachnoid cysts are uncommon in clinical practice and experience in their management may therefore be limited. Symptomatic cysts usually present with features of hydrocephalus due to obstruction of the third ventricle and aqueduct, and occlusion or partial obstruction of both foramina of Monro. Several treatment techniques have been used including stereotactic aspiration, microsurgical excision and shunting, but the best method of treatment remains unclear and the role of endoscopy is not yet established. We report our experience in a series of seven patients who had endoscopic treatment for prepontine arachnoid cysts; five were children under 15 years old who presented with delayed development and/or enlarged heads. The two adult patients, both of whom had insertion of shunts as children, presented with headache and vomiting due to shunt blockage. All patients improved following endoscopic cyst fenestration. There was no operative morbidity and there have been no relapses to date. Endoscopic fenestration of prepontine arachnoid cysts appears to be an effective method of treatment.     

Cystic supratentorial gliomas: natural history and evaluation of modes of surgical therapy

The management of cystic supratentorial gliomas is hampered by lack of documentation of the natural history of these lesions and by a lack of evaluation of modes of surgical therapy. We analyzed these factors in 25 patients with solitary cysts operated upon over a 20-year period. Two distinctive patterns of symptoms were seen: short duration (increased pressure and hemiparesis), most often heralding a malignant lesion, and long duration (commonly seizure disorder), associated more often with a benign pathological condition. Large solitary cysts were found in tumors of all histological grades. Surgical procedures included extirpation, biopsy/partial resection, cyst communication to ventricle or marsupialization, burr hole aspiration, aspiration via an indwelling reservoir, and cyst-peritoneal shunting. Radiotherapy, given in all cases, did not prevent cyst recurrence. Of the 25 patients, 76% are alive and remain cyst free at follow-up intervals of 1 to 16 years (mean, 3.2). Five patients died from their tumors, with a mean survival of 33 months after decompression. In 7 of 8 patients with cysts largely or entirely within the basal ganglia or thalamus, successful operative cyst control was achieved. Patients with solitary cystic gliomas seem to have a favorable prognosis, and vigorous efforts to control cyst recurrence and limit disability are warranted. Analysis of our data suggests that craniotomy for tumor resection, cyst decompression, and tissue diagnosis is the initial procedure of choice. Cyst recurrence without major solid tumor should be controlled by computed tomography-guided tap or shunt drainage. Reexploration is indicated when cyst reaccumulation is accompanied by clear regrowth of a solid component.     

Diagnosis and treatment of colloid cysts of the third ventricle by stereotactic drainage. Report on eleven cases

Between December 1979 and September 1986, 11 patients with colloid cysts of the third ventricle were operated on by a stereotactic procedure with Talairach's system. Stereoscopic angiography and ventriculographic study allowed for a percutaneous (twist-drill hole diameter: 2.5 mm) stereotactic aspiration of the cysts. The operations were successful, and there were no intraoperative or postoperative mortalities but just mild transient morbidity in three cases. Six cysts were evacuated completely, and five only partially. The mean residual volume was 19% of the initial one. Clinical and anatomical results are presented, and the advantages of this stereotactic procedure are discussed.     

Endobronchial ultrasonography in a patient with a mediastinal thoracic duct cyst

Mediastinal thoracic duct cysts are rare clinical findings. We report the case of a symptomatic 58-year-old woman in whom a thoracic duct cyst was successfully treated with surgical resection. Preoperative endobronchial ultrasonography revealed an oval-shaped hypoechoic area with a distinct, thick pedicle, gradual intermittent flux of the fluid content within the lesion, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) revealed lymphocyte predominant serous fluid without malignancy, which is consistent with features of a mediastinal thoracic duct cyst. We postulate that EBUS-TBNA can be used as a preoperative diagnostic tool for patients with possible mediastinal thoracic duct cysts.