gms | German Medical Science

Objective: Lesions of the pineal region remain a challenging target for neurosurgeons because they are deep seated and surrounded by vital structures. The occipital transtentorial and the infratentorial supracerebellar approach are the most frequently used surgical routes to the pineal region. We modified the paramedian infratentorial supracerebellar approach to be suitable for minimally invasive removal of pineal region lesions and describe the technique of pure endoscopic removal of such tumors.

Methods: Ten patients underwent surgery for pineal region tumor via a paramedian infratentorial supracerebellar keyhole approach (PISKA). 4 patients presented with non-specific neurological symptoms, three patients were admitted with acute hydrocephalus. 2 patients never had any complaints and where assessed by MRI for other reasons. Endoscope-controlled microsurgical (ECM) technique was applied using 4 mm rigid endoscopes with 0 and 30 degrees viewing angle and a full HD video system (B.Braun/Aesculap, Tuttlingen).

Results: Patients were operated in a prone position. An approximately 4 cm vertical skin incision was placed about 3 cm paramedian extending from slightly above the linea nuchae towards the cranio-cervical junction. A 2x1.5 cm bone flap was achieved with its upper border parallel to the transvers sinus. Dissection of the supracerebellar infratentorial route and tumor removal was performed in pure ECM technique. Tumor removal was accomplished first by decompression of the tumor and then dissection of the surface from the surrounding structures. The neuropathalogical examination revealed pineocytomas (n=3), pineal cysts (n=3), germinoma (n=1), lipoma (n=1), medulloblastoma (n=1), glioblastoma multiforme (n=1). Complete tumor removal was achieved in 8 patients, and subtotal resection in 2 patients. 4 patients developed postoperatively transient Parinaud's syndrome and gait ataxia.

Conclusions: The PISKA has proofed to be a safe and effective minimal invasive approach to pineal region lesion. It is suitable for the use of pure endoscopic technique and therefore for considerable reduction of tissue traumatization by enabling the same surgical possibilities resulting in a high level of complete tumor removals and improved visualization of all deep seated neurovascular structures. Our results for different indications are exhortative comparable to the results achieved with standard microsurgical technique. Therefore, we recommend this approach as a valuable option to the standard approaches.