Minim Invasive Neurosurg 2006; 49(4): 220-226
DOI: 10.1055/s-2006-948000
Original Article

© Georg Thieme Verlag KG · Stuttgart · New York

Morphological Study of the Spinal Canal Content for Subarachnoid Endoscopy

M. Zaaroor 1 , G. Kósa 2 , A. Peri-Eran 3 , I. Maharil 4 , M. Shoham 2 , D. Goldsher 3
  • 1Department of Neurosurgery, Rambam Medical Center, Haifa, Israel
  • 2Medical Robotics Laboratory, Department of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
  • 3Department of Radiology, Rambam Medical Center, Haifa, Israel
  • 4Department of Orthopedic Surgery, Carmel Medical Center, Haifa, Israel
Further Information

Publication History

Publication Date:
13 October 2006 (online)

Abstract

Study Design and Objective: This study was designed to examine the morphology of the spinal dural sac and contents, using magnetic resonance imaging in order to define the inner geometrical dimensions that confine the manoeuvre of an endoscope inserted in the lumbar region and along the thoracic and cervical spine. Background: The morphology of the spine has been studied since the development of myelography. However, most studies have measured the diameters of the spinal cord only, not the size of the subarachnoid space. In addition, the few studies available on the subarachnoid space have focused on the cervical spine, leaving a near-complete dearth of data on the subarachnoid space dimensions along the thoracic spine. Methods: Based on MRI images of the spine from 42 patients, the dimensions of the spinal cord, dural sac, and subarachnoid space were measured at mid-vertebral and inter-vertebral disc levels. Results: It was found that at each selected transverse level, the subarachnoid space tends to be symmetrical on the right and left sides of the cord, and measures 2.5 mm on average. However, the posterior and anterior segments, measured on the mid-sagittal plane, are generally asymmetrical and vary widely in size, ranging from 1 to 5 mm. These measurements match those found in previous studies, where these are available. The coefficient of variance for the dimensions of the subarachnoid space is as high as 42.4%, while that for the dimensions of the spinal cord is 10-15%. Conclusions: The findings presented here expand our knowledge of the spinal canal's morphology, and show that an endoscope designed to travel within the subarachnoid space must be smaller than 2.5 mm in diameter.

References

  • 1 Shapiro R. Myelography. Chicago: Year Book Medical Publisher 1975
  • 2 Thijssen HOM, Keyser A, Horstink MWM, Meijer E. Morphology of the cervical spinal cord on computed myelography.  Neuroradiology. 1979;  18 57-62
  • 3 Yu YL, du Boulay GH, Stevens JM, Kendall BE. Morphology and measurements of the cervical spinal cord in computer-assisted myelography.  Neuroradiology. 1985;  27 399-402
  • 4 Yone K, Sakou T, Yanase M, Ijiri K. Preoperative and postoperative magnetic resonance image evaluation of the spinal cord in cervical myelopathy.  Spine. 1992;  17 388-392
  • 5 Fujiwara K, Yonenobu K, Hiroshima K, Ebara S, Yamashita K, Ono K. Morphometry of the cervical spinal cord and its relation to pathology in cases with compression myelopathy.  Spine. 1988;  13 1212-1216
  • 6 Yirout Y. Pneumomyelographia. Prague, Gosudarstvennoe Izdatelstvo Medicinskoj Literatury 1964
  • 7 Inoue H, Ohmori K, Takatsu T, Teramoto T, Ishida Y, Suzuki K. Morphological analysis of the cervical spinal canal, dural sac and spinal cord in normal individuals using CT myelography.  Neuroradiology. 1996;  38 148-151
  • 8 Stanley YM, Schabel SI, Frey GD, Hungerford GD. Quantitative analysis of the cervical spinal canal by computed tomography.  Neuroradiology. 1986;  28 139-143
  • 9 Okada Y, Ikata T, Katoh S, Yamda H. Morphologic analysis of the cervical spinal cord, dural sac and spinal canal by magnetic resonance imaging in normal adults and patients with cervical spondylotic myelopathy.  Spine. 1994;  19 2331-2335
  • 10 Muhle C, Wiskirchen J, Weinert D. et al . Biomechanical aspects of the subanachnoid space and cervical cord in healthy individuals examined with kinematic magnetic resonance imaging.  Spine. 1998;  23 556-567
  • 11 Simpson G, Roe A, Lewontine RC. Quantitative Zoology. New York, Harcourt Brace & Co 1960

Correspondence

Prof. Moshe Shoham

Medical Robotics Laboratory·Department of Mechanical Engineering· Technion - Israel Institute of Technology

Technion City

Haifa 32000

Israel

Phone: +972/4/829 32 64

Fax: +972/4/829 57 11

Email: shoham@technion.ac.il

    >