A Neuroendoscopic Approach to the Aqueduct via the Fourth Ventricle Combined with Suboccipital Craniectomy

Abstract

Objectives: We have tried to approach the aqueduct less invasively with the endoscope in combination with a small suboccipital craniectomy, especially for lesions of the aqueduct close to the fourth ventricle.

Methods: The patient is placed in the prone position and a small suboccipital craniectomy is performed. After elevating the bilateral tonsils with retractors, the sheath of the endoscope is inserted from a small skin incision made on the posterior midline of the neck, far from the craniectomy site. The skin incision for endoscopic insertion is planned on the linear extension connecting the aqueduct and the foramen of Magendi on the craniocervical MRI. A rigid endoscope is inserted through the fourth ventricle to the aqueduct for exploration and surgical manipulation.

Results: Two cases with hydrocephalus due to aqueductal stenosis, with gait disturbance were operated. After exploration of the aqueduct via the fourth ventricle, endoscopic aqueductal plasty was performed. The postoperative courses were uneventful. The patients' symptoms disappeared.

Conclusions: This approach can be applied for less invasive endoscopic exploration and surgery around the aqueduct close to the fourth ventricle with a rigid endoscope, without overflexion of the neck, or a large craniectomy, or overretraction of the tonsils, or incision of the inferior vermis.

Key words

Neuroendoscope - aqueduct - approach via the fourth ventricle - microsurgery

References

• 1 Takimoto H, Iwaisako K, Kubo S, Yamanaka K, Karasawa J, Yoshimine T. Transaqueductal aspiration of pontine hemorrhage with the aid of a neuroendoscope. Technical note.  J Neurosurg. 2003;  98 917-919
• 2 Buxton N, Robertson I. Endoscopic approach to tectal tumors.  J Neurosurg. 2000;  93 152-153
• 3 Fukushima T. Flexible endoneurosurgical therapy for aqueductal stenosis.  Neurosurgery. 1994;  34 379
• 4 Matula C, Reinprecht A, Roessler K, Tschabitscher M, Koos W T. Endoscopic exploration of the IVth ventricle.  Minim Invasive Neurosurg. 1996;  39 86-92
• 5 Oka K, Yamamoto M, Ikeda K, Tomonaga M. Flexible endoneurosurgical therapy for aqueductal stenosis.  Neurosurgery. 1993;  33 236-242 discussion 242-243
• 6 Schroeder H W, Gaab M R. Endoscopic aqueductoplasty: technique and results.  Neurosurgery. 1999;  45 508-515 discussion 515-518
• 7 Shin M, Morita A, Asano S, Ueki K, Kirino T. Neuroendoscopic aqueductal stent placement procedure for isolated fourth ventricle after ventricular shunt placement. Case report.  J Neurosurg. 2000;  92 1036-1039
• 8 Kellogg J X, Piatt Jr J H. Resection of fourth ventricle tumors without splitting the vermis: the cerebellomedullary fissure approach.  Pediatr Neurosurg. 1997;  27 28-33
• 9 Strauss C. The anatomical aspects of a surgical approach through the floor of the fourth ventricle.  Acta Neurochir (Wien). 1998;  140 1099
• 10 Hamada H, Hayashi N, Endo S, Kurimoto M, Hirashima Y, Takaku A. Endoscopic aqueductal plasty via the fourth ventricle through the cerebellar hemisphere under navigating system guidance technical note.  Neural Med Chir (Tokyo). 1999;  39 950-952 discussion 952-954
• 11 Oi S, Sato O, Matsumoto S. Neuro-endoscopic surgery: recent advances [in Japanese].  No Shinkei Geka. 1995;  23 477-484
• 12 Kamikawa S, Takimoto H. Neuroendoscopic surgery present and future [in Japanese].  No Shinkei Geka. 2002;  30 253-272
• 13 Matula C, Tschabitscher M, Day J D, Reinprecht A, Koos W T. Endoscopically assisted microneurosurgery.  Acta Neurochir (Wien). 1995;  134 190-195
• 14 Harris L W. Endoscopic techniques in neurosurgery.  Microsurgery. 1994;  15 541-546
• 15 Decq P, LeGuerinel C, Brugieres P. et al . Endoscopic management of colloid cysts.  Neurosurgery. 1998;  42 1288-1294 discussion 1294-1296
• 16 Yamamoto Y, Ohmoto T. Nodular medulloblastoma.  J Neurosurg. 2000;  93 723-724
• 17 Veelen-Vincent M L van, Pierre-Kahn A, Kalifa C. et al . Ependymoma in childhood: prognostic factors, extent of surgery, and adjuvant therapy.  J Neurosurg. 2002;  97 827-835
• 18 Sandberg D I, Souweidane M M. Hemifacial spasm caused by a pilocytic astrocytoma of the fourth ventricle.  Pediatr Neurol. 1999;  21 754-756