Expansive Duraplasty Research Articles

Transnasal odontoid resection followed by posterior decompression and occipitocervical fusion in children with Chiari malformation Type I and ventral brainstem compression

In rare cases, children with a Chiari malformation Type I (CM-I) suffer from concomitant, irreducible, ventral brainstem compression that may result in cranial neuropathies or brainstem dysfunction. In these circumstances, a 360 degrees decompression supplemented by posterior stabilization and fusion is required. In this report, the authors present the first experience with using an endoscopic transnasal corridor to accomplish ventral decompression in children with CM-I that is complicated by ventral brainstem compression. Two children presented with a combination of occipital headaches, swallowing dysfunction, myelopathy, and/or progressive scoliosis. Imaging studies demonstrated CM-I with severely retroflexed odontoid processes and ventral brainstem compression. Both patients underwent an endoscopic transnasal approach for ventral decompression, followed by posterior decompression, expansive duraplasty, and occipital-cervical fusion. In both patients the endoscopic transnasal approach provided excellent ventral access to decompress the brainstem. When compared with the transoral approach, endoscopic transnasal access presents 4 potential advantages: 1) excellent prevertebral exposure in patients with small oral cavities; 2) a surgical corridor located above the hard palate to decompress rostral pathological entities more easily; 3) avoidance of the oral trauma and edema that follows oral retractor placement; and 4) avoidance of splitting the soft or hard palate in patients with oral-palatal dysfunction from ventral brainstem compression. The endoscopic transnasal approach is atraumatic to the oral cavity, and offers a more superior region of exposure when compared with the standard transoral approach. Depending on their comfort level with endoscopic surgical techniques, pediatric neurosurgeons should consider this approach in children with pathological entities requiring ventral brainstem decompression.

Posttraumatic spinal cord tethering and syringomyelia: surgical treatment and long-term outcome

Permanent neurological loss after spinal cord injury (SCI) is a well-known phenomenon. There has also been a growing recognition and improved understanding of the pathophysiological mechanisms of late progressive neurological loss, which may occur after SCI as a result of posttraumatic spinal cord tethering (SCT), myelomalacia, and syringomyelia. A clinical study of 404 patients sustaining traumatic SCIs and undergoing surgery to arrest a progressive myelopathy caused by SCT, with or without progressive myelomalacia and cystic cavitation (syringomyelia) was undertaken. Both objective and subjective long-term outcomes were evaluated. To the authors' knowledge, this is the first series of this size correlating long-term patient perception of outcome with long-term objective outcome analyses. During the period from January 1993 to November 2003, 404 patients who had previously sustained traumatic SCIs underwent 468 surgeries for progressive myelopathies attributed to tethering of the spinal cord to the surrounding spinal canal, with or without myelomalacia and syrinx formation. Forty-two patients were excluded because of additional pathological entities that were known to contribute to a progressive myelopathy. All surgeries were performed by the same neurosurgeon at a single SCI treatment center and by using a consistent surgical technique of spinal cord detethering, expansion duraplasty, and when indicated, cyst shunting. Outcome data were collected up to 12 years postoperatively. Comparisons of pre- and postoperative American Spinal Injury Association sensory and motor index scores showed no significant change when only a single surgery was required (86% of patients). An outcome questionnaire and phone interview resulted in > 90% of patients self-assessing arrest of functional loss; > 50% of patients self-assessing improvement of function; 17 and 18% self-assessing improvement of motor and sensory functions to a point greater than that achieved at any time postinjury, respectively; 59% reporting improvement of spasticity; and 77% reporting improvement of hyperhidrosis. Surgery for spinal cord detethering, expansion duraplasty, and when indicated, cyst shunting, is a successful treatment strategy for arresting a progressive myelopathy related to posttraumatic SCT and syringomyelia. Results suggest that surgery leads to functional return in ~ 50% of patients, and that in some patients posttraumatic SCT limits maximal recovery of spinal cord function postinjury. A patient's perception of surgery's failure to arrest the progressive myelopathy corresponds closely with the need for repeat surgery because of retethering, cyst reexpansion, and pseudomeningocele formation.

External decompressive craniectomy including resection of temporal muscle and fascia in malignant hemispheric infarction

Decompressive craniectomy procedures are used for malignant hemispheric infarctions. However, the temporal muscle and fascia are significant limiting factors for external herniation of an edematous brain. Therefore, the authors performed a decompressive craniectomy and expansive duraplasty combined with resection of the temporal muscle and fascia for 15 patients with a malignant hemispheric infarction. The volume of the maximum external herniation that was measured on the basis of a CT volumetry study ranged from 130 to 300 ml (mean +/- standard deviation, 200 +/- 64 ml) on postoperative Day 3.2 +/- 1.5 (range 2-5 days postoperatively). The mean value represented a 2-fold volume expansion in comparison with the conventional decompressive craniectomy, and the greater the external herniation obtained by external decompression, the smaller the midline brain shift after surgery. The mortality rate, favorable outcomes (modified Rankin Scale Scores 1-3), and unfavorable outcomes were 20, 60, and 20%, respectively, and the masticatory function was only minimally affected. Furthermore, a cranioplasty involving reconstruction of the temporal muscle defect performed using a MEDPOR implant resulted in good cosmetic outcomes with no temporal hollow. Resection of the temporal muscle in a decompressive craniectomy was shown to provide greater decompression and better clinical outcomes for malignant hemispheric infarctions at an acceptable cost of minimal masticatory dysfunction and cosmetic disfigurement.

Intracerebral Hematoma

See related article, pages 2457–2462. The signs and symptoms of acute intracranial hemorrhage are those of a rapidly developing mass lesion, compounded over time by surrounding edema, and sometimes by brain herniation. These are dramatic, debilitating, and often fatal events, but does the pathophysiology of intracranial hemorrhage extend beyond that of mass effect? Blood contains several factors that are potentially, and in some cases definitively, neurotoxic. Chief among these are hemoglobin and its breakdown products, heme and iron, which exhibit neurotoxicity at low micromolar concentrations through mechanisms involving iron-catalyzed production of reactive oxygen species.1,2 Brain has …

Expansive duraplasty for the treatment of spinal extradural arachnoid cysts

The authors report the case of a 25-year-old man with a thoracolumbar extradural arachnoid cyst who underwent expansive duraplasty. Symptoms, preoperative magnetic resonance imaging features, and intraoperative findings suggested the involvement of entrapment neuropathy in the manifestation of symptoms. To the authors' knowledge, this case represents the first evidence that expansive duraplasty can achieve complete resolution of the symptoms in a patient with a spinal extradural arachnoid cyst. The results indicate that duraplasty may be an alternative option in cases in which complete resection of the lesion is difficult and widening of the dural sac is necessary at surgery.

Malignant cerebellar swelling in Behçet disease

Behcet disease is an idiopathic, multisystem inflammatory disorder characterized by oral and genital ulcerations, uveitis, and skin lesions. 2,5 Types of neurological involvement that have been described include parenchymal lesions (frequently of the brainstem), venous thrombosis, and meningoencephalitis. 1,3 We report a unique presentation of neuro-Behcet disease that necessitated neurosurgical intervention. This 13-year-old boy with Behcet disease presented with complaints of headaches. Magnetic resonance imaging revealed no evidence of supratentorial or posterior fossa venous thrombosis, although it did demonstrate leptomeningeal enhancement and cerebellar edema, causing fourth ventricular compression and tonsillar herniation (Fig. 1). Despite high-dose corticosteroid therapy, a Cushing reflex acutely developed in the patient due to brainstem compression (Fig. 1), with crescendo headaches, bradycardia, and systemic hypertension. An urgent suboccipital craniectomy with expansive duraplasty resulted in normalization of his blood pressure and heart rate. His initial recovery was uneventful, but 3 weeks postoperatively a tense pseudomeningocele developed (coinciding with a steroid taper) that necessitated reinstitution of steroid agents, duraplasty, and temporary cerebrospinal fluid diversion. The patient remains neurologically intact at last follow up. Although the underlying cause of Behcet disease and its neurological manifestations remain unknown, recent evidence suggests that interleukin-2 receptor‐bearing T cells play a primary role in the disease pathogenesis. 4 Despite chronic medical therapy for Behcet disease, malignant cerebellar swelling with acute brainstem compression necessitated suboccipital decompression in this patient. References

Surgical management of syringomyelia associated with spinal adhesive arachnoiditis

Summary The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.