The utility of calcium phosphate cement in cranioplasty following retromastoid craniectomy for cranial neuralgias.

BACKGROUND: Following retromastoid craniectomy for microvascular decompression of the fifth or seventh cranial nerve, the preferred method and value of cranioplasty remains disputed. METHODS: In this study, we report the functional outcome of calcium phosphate cranioplasty following first-time microvascular decompression in 79 consecutive patients who underwent operations over a one-year period. RESULTS: No patient experienced a deep infection, cerebrospinal fluid leak or undue incisional pain at long-term follow-up. Additionally, all patients stated that they were satisfied with the cosmetic outcome. DISCUSSION: Although this technique is unlikely to affect the rates of infection and postoperative pain, we believe that the low rate of CSF leak provides a unique advantage over other currently used methods of closing retromastoid craniectomies.

[Posterior extrusion of Biocompatible Orthopaedic Polymer (BOP) graft mimicking a calcified lumbar disc herniation: case report]. / Expulsion postérieure d'un greffon de Biocompatible orthopaedic polymer (BOP) mimant une hernie discale calcifiée lombaire: à propos d'un cas.

OBJECTIVE AND IMPORTANCE: We present a case of intracanalar extrusion of a L5S1 Biocompatible Orthopaedic Polymer (BOP) graft associated with a L4L5 disc herniation 19 years after a lumbar intersomatic fusion for a L5S1 disc herniation. Radiological aspect of this complication should be recognized by neurosurgeons. CLINICAL PRESENTATION: A 55-year old man presented with a right L5 sciatic pain. Neurological examination found a severe weakness in dorsal flexion of the foot. A lumbar CT scanner disclosed aspects consistent with right L4L5 and huge calcified L5S1 lumbar disc herniation. INTERVENTION: The patient was operated via a bilateral paravertebral approach and a L5 laminectomy. A dense and extensive epidural scarring was seen. The right L4L5 herniated disc was excised. At the left L5S1 level, fibres from a BOP graft had separated into large fragments extruded into the vertebral canal through the dura. The fibres could only be removed partially because of nerve roots adherence. The patient developed postoperative cerebrospinal fluid (CSF) leakage that required a second operation for dural closure. The postoperative course was uneventful and the patient recovered the right L5 root deficit. CONCLUSION: Neurosurgeons should be aware of the radiological aspect of this complication. If it is recognized on CT scan and asymptomatic, conservative management should be proposed because of the risk of nerve roots injury or postoperative CSF leakage.

Postoperative complications associated with dural substitutes in suboccipital craniotomies.

OBJECTIVE: Dural replacements are used in cranial surgery when primary closure of native dura is not possible. The goal is to recreate a watertight barrier to prevent cerebrospinal fluid leakage with few associated complications. We reviewed a single-institution experience with a variety of dural substitutes in posterior fossa neurosurgery, for which higher complication rates are well described. METHODS: Patients were screened for suboccipital posterior fossa neurosurgery between November 2005 and April 2007. Surgical logs were reviewed for diagnosis, procedure, and use of dural replacement. Clinical courses were reviewed for hydrodynamic complications, including delayed hydrocephalus, clinically significant pseudomeningocele, aseptic meningitis, and persistent cerebrospinal leakage. RESULTS: One hundred twenty-eight patients were included, and a dural replacement was used in 106. Overall, the complication rate was 21.9% (28 patients). Complications were seen for acellular human dermis in 33.3%, for collagen matrix in the original formulation in 18.2%, for the reformulation in 16.9%, for the suturable formulation in 50%, for nonautologous materials in 24%, and for no dural replacement in 16.7%. Univariate and multivariate analysis demonstrated that hydrodynamic complications were associated with use of the suturable collagen matrix (odds ratio, 10.8; 95% confidence interval, 2.5-46.1; P = 0.0014) and trended with use of acellular human dermis (odds ratio, 4.6; 95% confidence interval, 0.9-23.1; P = 0.06). CONCLUSION: The increased risk of hydrodynamic complications associated with suboccipital neurosurgery is modified by choice of dural replacement. Similar complication rates were seen for most materials with a variety of primary abnormalities, with the exception of suturable bovine collagen matrix, with hydrodynamic complications in 50% of patients.

Treatment of a persistent iatrogenic cerebrospinal fluid-pleural fistula with a cadaveric dural-pleural graft.

BACKGROUND CONTEXT: A cerebrospinal fluid (CSF)-pleural fistula is a unique condition with which all spine surgeons need to be familiar, particularly those who use anterolateral approaches to the thoracic region. When direct suturing of the dural defect is not possible, techniques for indirect repair must be considered. PURPOSE: To report a novel technique for repair of a thoracic CSF-pleural fistula with a cadaveric dural-pleural graft after failure of initial treatment with Duragen (Integra, Plainsboro, NJ) and fibrin glue. STUDY DESIGN/SETTING: Case report/University of Miami/Jackson Memorial Medical Center. METHODS: The case of a 65-year-old female is presented. RESULTS: The patient represented 5 weeks after the initial operation (left-sided thoracotomy, partial T10-T11 corpectomy and removal of an intradural calcified disc) with dyspnea and severe positional headaches. Imaging of the brain revealed a subdural hematoma and magnetic resonance imaging of the thoracic region demonstrated a pseudomeningocele surrounding the postsurgical bed. She underwent a revision thoracotomy and CSF-pleural fistula repair. We addressed the dural opening indirectly by suturing a piece of cadaveric dural allograft to the thickened pleura, after Duragen and fibrin glue were placed over the dural defect. A lumbar drain and a chest tube were also placed. At 12 weeks post-op, the subdural hematoma had completely resolved and her chest X-rays demonstrated a significant decrease in the CSF-pleural collection. CONCLUSION: Anterolateral thoracic disc surgery poses a great challenge to the spine surgeon but can provide the most direct way of decompressing the spinal cord as a result of ventral pathology. Some of the most difficult aspects of dealing with a CSF leak in this area relates to 1) the relative complexity of suturing the dura directly as it is at a considerable distance from the operating surgeon; 2) the manner in which the contralateral dura slopes away and is hidden from view; and 3) the relatively negative intrathoracic pressure, which encourages the persistent flow of CSF from the intradural to the pleural cavity. We speculate that with open thoracic surgery and the creation of a large potential space with an open dural defect, this technique provided an additional barrier against the formation of a CSF-pleural fistula. Using this technique, we intentionally create a pseudomeningocele into the corpectomy defect that is contained within the confines of our dural-pleural graft.