Clinical guiding significance of abdominal organs projection on the lateral lumbar X-ray for spinal microendoscopy punctures.

AIMS: To measure the anatomical structure of lumbar spine by computed tomography (CT) scan, and explore the posterior edge of abdominal organs on the lateral lumbar X-ray in lateral puncture, in order to provide an anatomical basis for spinal microendoscopy to avoid abdominal organ injury.

METHODS: A total of 50 patients with abdominal enhanced CT scan in our hospital were included. The spine from L1 to S1 were divided into 16 axial levels (containing the superior level of vertebral body, middle part of vertebral body, and inferior level of vertebral body) to make out safety zone, critical puncture point and critical angle in accordance with the anatomical position of posterior renal fascia and parietal peritoneum on the lateral lumbar X-ray.

RESULTS: From L1 to S1, the projection of the lowest point of the posterior renal fascia and parietal peritoneum and the projection of the critical puncture point turns from the dorsal side of the posterior vertebral body to the ventral side. And the two projection points are in the same position on the middle level of L4 vertebral body, which is on the posterior margin of L4 vertebral body. The critical puncture angle is also gradually reduced, and is approximate 0° at the middle level of L4. There is no statistically significant difference between left and right side of the body.

CONCLUSION: The safety zone, critical puncture point and critical angle of L1-S1 were determined in accordance with the projection of the lowest point of the posterior renal fascia and parietal peritoneum, which provided an anatomical guidance for avoiding the injury of posterior renal fascia or abdominal organs during operation.