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E Zarzur

Publications and source records attributed to E Zarzur.

9 recordsLinked to original sources
PubMed1996

The shape of the human lumbar vertebral canal.

Literature on the anatomy of the human vertebral column characterizes the shape of the lumbar vertebral canal as triangular. The purpose of the present study was to determine the precise shape of the lumbar vertebral canal. Ten lumbar vertebral columns of adult male cadavers were dissected. Two transverse sections were performed in the third lumbar vertebra. One section was performed at the level of the lower border of the ligamenta flava, and the other section was performed at the level of the pedicles. The shape of the lumbar vertebral canal at the level of the pedicles tends to be oval or circular, whereas the shape of the lumbar vertebral canal at the level of the lower border of the ligamenta flava is triangular. Thus, the shape of the human lumbar vertebral canal is not exclusively triangular, as reported in the literature. It is related to the level of the transversal section performed on the lumbar vertebra. This finding should be taken into consideration among factors involved in the spread of solutions introduced into the epidural space.

Adult↗
PubMed1996

Mechanical properties of the human lumbar dura mater.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the transverse and longitudinal distensibility of the posterior human lumbar dura mater. Results are compared with previous literature on biomechanical property studies. Possible clinical implications were also examined. METHODS: Samples of human dural sac were obtained from autopsy studies in three adult male cadavers. Dural sac samples were sectioned longitudinally to measure transverse and longitudinal distensibility, thickness and circumference. RESULTS: It was recorded that the posterior lumbar dura mater was easily distensible only in the transverse direction. The longitudinal force required to distend and rupture the posterior lumbar dura mater samples is 3.5 to 6.7 times greater than the force to produce a transversal rupture. CONCLUSION: Depending on the local cerebrospinal fluid pressure, the documented easier transverse distensibility of the posterior lumbar dura mater may allow greater contact of the lumbar dural sac with the wall of the lumbar vertebral canal. This fact may affect the diffusion of solutions introduced into epidural space.

Adult↗
PubMed1984

Genesis of the 'true' negative pressure in the lumbar epidural space. A new hypothesis.

A hypothesis is suggested that the initial or 'true' negative pressure encountered when a needle first enters the epidural space is due to initial bulging of the ligamentum flavum in front of the advancing needle followed by its rapid return to the resting position once the needle has perforated the ligament. The bulging has been confirmed to occur in fresh cadavers, and pressure studies carried out during performance of epidural blocks in patients lend weight to this hypothesis.

Adolescent↗
PubMed1984

Anatomic studies of the human ligamentum flavum.

Lumbar segments of the vertebral column were dissected in 10 human cadavers to identify anatomic features of practical value in performance of spinal or lumbar epidural anesthesia. Of special interest were the findings that the ligamentum flavum at L2-3 is 3-5-mm thick, 12-22-mm wide, and that the internal surfaces of the right and left ligamenta flava form an acute angle with its vertex in contact with the interspinous ligament.

Adult↗
PubMedDate not supplied

The resistance of the human dura mater to needle penetration.

METHODS: An aneroid manometer attached to a needle during lumbar puncture for spinal anesthesia was used to record the pressure in the epidural space, and an attempt was made to define the moment the needle contacted and indented the dura mater. RESULTS: By measuring the distance the needle travelled after contact with the dura and before its actual perforation, it was determined that the dura mater indents 2-6 mm. CONCLUSION: The finding indicated that the dura mater is relatively resistant to puncture.

Adult↗