Interactive image-guided transcallosal microsurgery for anterior third ventricular cysts

Endoscopic Versus Microsurgical Resection of Third Ventricle Colloid Cysts

Objective:

Endoscopic resection of colloid cysts has been performed as an alternative to microsurgical resection and stereotactic aspiration since 1982. To date, there are limited published studies comparing these procedures. In this study, we present the largest series of endoscopic resections published to date and compare outcomes to a cohort of microsurgical resections performed at the same institution.

Methods:

A retrospective chart review was conducted for all patients in the Calgary Health Region undergoing resection of a colloid cyst between 1991 and 2004. Comparison was made between patients treated with endoscopic resection versus microsurgical resection.

Results:

Twenty-five endoscopic and nine microsurgical procedures were performed. Complete resection was achieved in 24 of 25 procedures in the Endoscopic group, compared with all 9 procedures in the Microsurgical group. Patients in the Endoscopic group had a reduced operative time (mean 104 minutes versus 217 minutes) and reduced length of stay (3.8 days versus 8.4 days) compared to the Microsurgical group. One patient in the Endoscopic group had a complication (hemiparesis/pulmonary embolus). By contrast, 3 patients in the Microsurgical group had complications (seizure, ventriculitis/bone flap infection, and transient memory deficit). There was one recurrence in each group which both occurred at 5 years follow-up. The mean length of follow-up is 38 months in the Endoscopic group and 33 months in the Microsurgical group.

Conclusion:

Endoscopic resection of colloid cysts can be performed with significantly lower risk of complication than microsurgical resection and with equivalent surgical success. Operative time and length of hospital stay are both significantly reduced with endoscopic resection.

Complete Microsurgical Resection of Colloid Cysts with a Dual-port Endoscopic Technique

Objective:

A dual-port endoscopic approach, used for the surgical management of colloid cysts, was developed with the following goals: 1) a direct, unobstructed, high-illumination endoscopic view of the attachment point of the colloid cyst to the tela choroidea, and 2) a gross total resection of the colloid cyst capsule using microsurgical techniques.

Methods:

Eleven symptomatic, hydrocephalic, colloid cyst patients who underwent operation with a unilateral, precoronal-frontopolar dual-port endoscopic technique were retrospectively assessed. Preoperative magnetic resonance imaging scans were analyzed, comparing the lateral precoronal to the frontopolar approach, to determine the degree of angulation that would be required to directly view the roof of the third ventricle. Clinical outcome and radiographical follow-up were assessed.

Results:

The frontopolar approach achieved an approach angle to the roof of the third ventricle of only 15 ± 4 degrees compared with 56 ± 6 degrees (P< 0.0001) for the precoronal approach. The view obtained from the frontopolar endoscope allowed excellent visualization of the cyst attachment point. Microsurgical dissection techniques, using many standard microsurgical instruments introduced through the second port, were satisfactorily accomplished. Complete resections were obtained in 10 out of 11 dual-port patients. Worsening of memory deficits occurred in one patient. There was no cyst recurrence with a mean follow-up period of 26 ± 27 months.

Conclusion:

The dual-port endoscopic technique described is an alternative to classic microsurgical craniotomy approaches. The technique allows excellent visualization of the colloid cyst attachment and permits microdissection techniques.