Characteristics of patients with ruptured very small intracranial aneurysm sized less than 3 mm.

OBJECTIVE: If the size of an intracranial aneurysm is below 3 mm, clinicians rarely treat them because of the low risk of rupture. But subarachnoid hemorrhage (SAH) due to the rupture of very small intracranial aneurysm (VSIA) (saccular aneurysm sized less than 3 mm) may lead to many critical neurological complications. So we analyzed the characteristics and differences between the ruptured VSIA group and the ruptured non-VSIA group. METHODS: 421 saccular aneurysms from patients with SAH between January 2016 and December 2019 were included. Patient information including age, sex, and medical history and information about the aneurysm including location, size, aspect ratio, inflow angle, and height-width ratio were collected. And we compared the VSIA group with non-VSIA group about these characteristics. RESULTS: 12.1% (51/421) of the aneurysms were included in the VSIA group, while the non-VSIA group consisted of 87.9% of the aneurysms (370/421). The female predominance was significantly higher in the VSIA group than that in the non-VSIA group (p=0.011). No significant difference was observed in location, medical history, height-width ratio between the groups. The mean value of the inflow angle in the VSIA group was much lower than that in the non-VSIA group, but no statistically significant association between rupture risk and the inflow angle was observed. The average aspect ratio was significantly lower than that in the non-VSIA group. CONCLUSIONS: Ruptured VSIA group has higher percentage of females and lower aspect ratio than ruptured non-VSIA group. Further studies regarding the characteristics of ruptured and unruptured VSIA patients is required for assistance in clinical decision related to treatment of VSIA group before the aneurysmal sac rupture.

Fracture-dislocation of L5 Combined with Multi-level Traumatic Spondylolisthesis of the Lower Lumbar Spine Treated via the Posterior-only Approach: A Case Report.

Fracture-dislocation of the lower lumbar spine, which is commonly caused by high-impact trauma and can lead to instability in the spine, is relatively rare. Surgical treatment is indicated to restore spinal balance, weight-bearing ability, and decompression of the neural elements. There are various available surgical options, including the posterior-only or anterior-only approaches, or a combination of them. However, there is still no definite classification and treatment strategy for fracture-dislocation of the lower lumbar spine. In this report, we describe a 65-year-old man presenting cauda equina syndrome caused by a fracture-dislocation of L5 combined with multi-level traumatic spondylolisthesis of the lower lumbar spine. The patient was treated via the posterior-only approach with neural decompression and anterior reconstruction with posterior instrumentation. We discuss the reasons why the posterior-only approach was decided upon and several meaningful points during the surgery in detail.