PMC9326050_01
A 51-year-old male (case 1). (A) Sagittal magnetic resonance imaging (MRI) showed ventral fluid-filled collection in the spinal canal (VFCC) (white arrows) from C5 to T7. (B) Brain MRI showed a T2-weighted hypointensity in the superficial brain. (C) A fast imaging employing steady-state acquisition (FIESTA) image demonstrated a dural defect at the C7-T1 level (the white arrow). (D) An intraoperative picture of anterior approach (case 1): After the outer dura layer (white asterisks) was cut longitudinally, we found a dural defect (the black arrow) in the dura mater's inner layer. A bleeding clot was recognized between the inner and outer dural layers (the white arrow). (E) The dural defect was sutured using a 7-0 nylon. (F) The spine was reconstructed using a cage and a plate. (G) Post-operative MRI showed the dural defect was successfully repaired. (H) The outer layer of the dura was histologically examined using hematoxylin-eosin (HE) staining, showing rich collagen fibers with hemosiderin deposition. The bar: 125 mum.
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F1
Magnetic resonance imaging (MRI) showed a T2-weighted hypointensity in the superficial brain and along the spinal cord due to hemosiderin deposition (Figures 1A,B). Sagittal MRI image showed VFCC from C5 to T7 in the spinal canal (Figure 1B). A fast imaging employing steady-state acquisition (FIESTA) image demonstrated that a dural defect was suspected at the C7-T1 level (Figure 1C) and was confirmed by dynamic computed tomography (CT) myelography. The epidural space was completely exposed with approximately a 20-mm width, which revealed that the surface of outer dura mater is completely intact. Then, the dura (outer dura) was cut with a 20-mm longitudinal length, which revealed a 5-mm-long defect in the dura mater's inner layer (Figure 1D). The inner dural defect was closed using a 7-0 nylon suture (Figure 1E) and sealed with a fibrin glue. The superficial layer of the dura was histologically examined using hematoxylin-eosin staining, showing rich collagen fibers with hemosiderin deposition (Figure 1F). The spine was fused using a cage and a plate (Figure 1G). Post-operative MRI showed the dural defect was repaired (Figure 1H).
PMC9326050_02
A 69-year-old female (case 2). (A) Sagittal MRI showed VFCC from C3 to T2 in the spinal canal (white arrows). (B) Brain MRI showed a hemosiderin deposition in the superficial brain. (C) An axial FIESTA image demonstrated that a dural defect was located at the C7-T1 level (the white arrow). (D) An intraoperative picture of anterior approach (case 2): After the outer dura layer (white asterisks) was excised at the center, we found a dural defect (the black arrow) in the dura mater's inner layer. (E) Since the inner dural layer was extremely thin and fragile, the defect was repaired using a free fat graft. (F) The spine was fused using a cage and a plate. (G) Post-operative MRI showed the dural defect was repaired. (H) The histology of the outer layer (HE staining) demonstrated that rich collagen fibers were oriented in a longitudinal direction. The bar: 125 mum.
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F2
A T2-weighted MRI revealed hypointensity in the superficial brain and along the spinal cord, suggestive of hemosiderin deposition (Figures 2A,B). VFCC was observed from C3 to T2 on the sagittal images (Figure 2B). A dural defect was detected at the C7-T1 level on the axial FIESTA image (Figure 2C) and dynamic CT myelography. Then, the outer dura layer's center was cut longitudinally, which revealed a 4-mm-long defect in the dura mater's inner layer (Figure 2D). Since the inner dural layer was extremely thin and fragile, the defect was repaired using a free fat graft (Figure 2E). The histology of the superficial layer demonstrated that rich collagen fibers were oriented in a longitudinal direction (Figure 2F). The spine was fused using a cage and a plate (Figure 2G), and post-operative MRI showed the dural defect was repaired (Figure 2H).
PMC9326050_03
A 79-year-old male (case 3). (A) Sagittal MRI showed VFCC from C7 to T7 in the spinal canal (white arrows). (B) Brain MRI showed a hemosiderin deposition at the sulcus. (C) An axial FIESTA image at the T2 level demonstrated a defect located at the left paramedian anterior dura (the white arrow). (D) An intraoperative picture of posterior approach: The left ventral epidural space was dissected, and the surface of dura (outer dura: white asterisks) was pushed up from the anterolateral direction. The intact outer dura was observed through the dural defect, which was supposed to locate in the inner dura mater (the black asterisk). Hemosiderin deposition was observed on the spinal cord (black triangles). (E) The histology of the outer layer (HE staining) demonstrated rich collagen fibers. The bar: 125 mum.
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F3
A T2-weighted MRI indicated hemosiderin deposition on the superficial brain and the spinal cord (Figures 3A,B). VFCC was observed from C7 to T7 on the sagittal images (Figure 3B). T2 level on the axial FIESTA image (Figure 3C). There were no other findings, which could cause SS. We dissected the ventral epidural space and pushed the surface of dura (outer dura) from the anterolateral direction (Figure 3D). Similar to the anterior-approached cases, the histology of the superficial layer demonstrated rich collagen fibers oriented in a longitudinal direction (Figure 3E).