Dural decompression – a new surgical modality in the therapy of acute traumatic spinal cord injury

This is an unauthorised machine translation into English made using the DeepL Translate Pro translator. The editors do not guarantee that the content of the article corresponds fully to the original language version.

Dear Editor,

We present the case of a 38-year-old woman who was struck during the night while sleeping by a hanging bed frame that had been torn from the wall. She was transported to the Emergency Department of Masaryk Hospital in Ústí nad Labem. The patient had severe quadriparesis and was only able to perform internal rotation of her left lower limb. The initial CT scan revealed a sagittal split of the C5 body with marked stenosis of the spinal canal. MRI confirmed spinal cord compression with spinal cord edema from C4 to C6 (Fig. 1A, B). Three hours after admission to the hospital, an emergency C5 somatectomy was performed with stabilization using a plate and bicortical screws via an anterior approach, utilizing a tricortical graft from the iliac crest. The follow-up CT showed an appropriate postoperative finding. A lumbar drain was inserted with an inflow pressure of 14–15 mmHg. However, the follow-up MRI of the cervical spine revealed persistent significant edema with a hemorrhagic focus in the center of the spinal cord (Fig. 1C, D). Therefore, posterior decompression was performed via C4–6 laminectomy, with dural and arachnoid decompression and full-length plasticization using synthetic material (Fig. 2). The follow-up MRI showed adequate decompression of the spinal cord throughout its entire length (Fig. 1E, F). Neurological deficits gradually improved. Even during hospitalization, limb mobility improved, with muscle strength reaching 4/5 on the left limbs in some segments, while the right limbs showed minimal movement or tone in the plexuses with acral plegia. Thanks in part to active inpatient rehabilitation, further improvement gradually occurred. Eighteen months after surgery, the patient is able to walk with a cane and a brace on her right lower limb due to persistent right-sided hemiparesis. At home, she is able to move around even without a cane. Sensation is intact, and the sphincters are intact.

The recommended approach to the treatment of acute spinal cord trauma currently relies primarily on ensuring the stability of the injured spinal segment (rigid collar or corset, surgical fixation) and ensuring rapid extradural decompression of the spinal cord [1]. In patients with brain trauma, a standard component of the surgery (decompressive craniectomy) is the removal of a bone flap, which, according to various studies, leads to a reduction in intracranial pressure of nearly 40%. Opening the dura mater is then a matter of course, leading to a further reduction in intracranial pressure of more than 20% [2]. Dural decompression is an absolutely essential part of surgery for traumatic brain injury. In principle, we should perhaps proceed in the same way for spinal cord injuries. However, we currently have little data demonstrating the effect of dural decompression in spinal cord injuries on the reduction of intrathecal pressure and clinical outcomes. Yet some patients may have spinal cord compression caused solely by the dural sheath itself, without any additional extradural cause. In one study, the authors evaluated the origin of spinal cord compression in patients with spinal cord injury [3]. In three-quarters of these cases, the cause was extradural; however, one-quarter of the injuries were caused by dural compression. The DISCUS study is currently underway, which aims to assess the benefits of dural plasty in a planned cohort of 222 patients requiring spinal canal decompression. Our center is part of this international study.

Furthermore, according to current recommendations, it is indicated to maintain the mean arterial pressure (MAP) at 85–90 mmHg during the first week following spinal cord injury. However, the relationship between perfusion of the injured spinal cord and clinical outcomes may be better reflected by the intrathecal pressure or spinal cord perfusion pressure [4]. The concept of measuring intrathecal pressure using an established lumbar drain was first tested in a prospective clinical study as early as 2009 [5]. The study showed that this method helps detect phases of high intrathecal pressure and low perfusion pressure that we are otherwise unable to detect. In a subsequent study, microdialysis at values of high intradural pressure and low perfusion pressure demonstrated signs of ischemia, which may contribute to the progression of secondary spinal cord injury [6]. According to this small study, intradural pressure and spinal cord perfusion pressure values may be independent predictors of clinical outcome in patients with traumatic spinal cord injury. Measured intrathecal pressure may also help with targeting MAP in the first week following spinal cord injury. Lumbar drainage then allows cerebrospinal fluid to be aspirated when intrathecal pressure is elevated, thereby reducing the pressure. On the other hand, this form of treatment remains controversial, as unlike craniocerebral trauma, spinal cord injury is predominantly a focal issue, and reducing intrathecal pressure may not necessarily relieve high pressure at the site of the spinal cord injury. On the other hand, direct decompression of the spinal cord injury using dural plasty can relieve focal compression and potentially improve the prognosis for patients with traumatic spinal cord injury.

Traumatic spinal cord injury leads to varying degrees of inflammation, hemorrhage, and swelling of spinal cord tissue, resulting in increased intraspinal pressure and potentially leading to impaired spinal cord perfusion [6,7]. Dural decompression combined with decompression of the bony, ligamentous, and cartilaginous structures of the spinal canal may represent a potential new surgical modality in cases of persistent dural compression in individuals with acute spinal cord injury. However, further preclinical and clinical research is needed to demonstrate the clinical efficacy of this procedure.

Ethical aspects

Approved by the Ethics Committee of Krajská zdravotní, a. s., under reference number 307/10 on June 22, 2022.

Funding

This work was supported by an internal grant from the Grant Agency of Krajská zdravotní, a. s. (217111037).

Conflict of Interest

The authors declare that they have no conflict of interest in connection with the subject of the study.