Recurrent haemorrhagic pontine cavernoma resection via a retrosigmoid microsurgical approach.

BACKGROUND: Brainstem cavernomas occasionally require surgical treatment. Appropriate patient selection and thorough understanding of the anatomy and technical nuances involved in microsurgical resection is a pre-requisite in undertaking these challenging cases. CASE DESCRIPTION: We present a video case of a patient with a recurrent haemorrhagic pontine cavernoma. A step-by-step commentary of surgical footage is provided along with clinical, anatomical and technical learning points pertinent to the safe surgical management of these lesions.

Microsurgical clipping of ruptured supraclinoid internal carotid artery aneurysm with extradural clinoidectomy.

BACKGROUND: Supraclinoid Internal Carotid Artery (ICA) aneurysms require additional access to standard pterional craniotomy via extradural clinoidectomy. Existing texts and surgical videos lack clarity, explanation and a clear step by step process. CASE DESCRIPTION: We present a case of a ruptured supraclinoid ICA aneurysm and extradural clinoidectomy along with 3D reconstructed imaging of the case anatomy to guide its resection. Real-time unedited on table rerupture provides an example of management. CONCLUSION: Extradural Anterior Clinoidectomy is a key maneuver in cerebrovascular surgical armamentarium for clipping of supraclinoid aneurysms. Stereotypical Pathological or Surgical Anatomy, its application, and availability with 3D imaging should be facilitates the framing and learning of normal physiological anatomy.

Novel Application of the Pfirrmann Disc Degeneration Grading System to 9.4T MRI: Higher Reliability Compared to 3T MRI.

STUDY DESIGN: Reliability study. OBJECTIVE: To evaluate the applicability and reliability of 9.4T magnetic resonance imaging (MRI) in the assessment of degenerative disc disease compared with 3T MRI. SUMMARY OF BACKGROUND DATA: MRI is a reliable indicator of biochemical changes in the intervertebral disc (IVD) including hydration status, proteoglycan content, and disc degeneration compared with anatomical and histological studies. High-field 9.4T MRI has been shown to provide superior resolution and anatomical detail. However, it has not been tested against current standard MRI techniques. METHODS: Disc degeneration was initiated in 36 skeletally mature ewes 6 months prior to necropsy via validated surgical IVD injury models using either scalpel injury or drill-bit injury techniques at lumbar spine levels L2/3 and L3/4 with L1/2, L4/5, and L5/6 serving as control discs. All ex vivo IVDs were examined with 9.4T MRI and 3T MRI. All scans were analyzed using the Pfirrmann grading system by four independent observers. Intra- and interobserver reliability was assessed using kappa statistics and Spearman correlation. RESULTS: Inter- and intraobserver agreement for 9.4T MRI was excellent, both at κ 0.91 (P < 0.001). Comparatively, 3T interobserver reliability demonstrated substantial agreement at κ 0.61 (P < 0.001). Complete agreement was obtained in 92.7% to 100% of discs at 9.4T compared with 69.7% to 83.1% at 3T. A difference of one grade or more occurred in 6.7% at 9.4T and 39.3% at 3T. 9.4T MRI scored 97.3% of discs as grade 1 to 2 compared with 71.3% at 3T. 3T MRI tended to over-score the extent of disc degeneration with 28.6% of discs scored as grade 3 or higher compared with 2.7% at 9.4T MRI. CONCLUSION: 9.4T MRI study of IVD degeneration using the Pfirrmann grading system demonstrated excellent inter- and intraobserver reliability. Comparatively, 3T MRI demonstrated a tendency to over score the extent of disc degeneration. This improved reliability of 9.4T MRI holds great potential for its clinical applications. LEVEL OF EVIDENCE: 3.

A Comparison of Two Ovine Lumbar Intervertebral Disc Injury Models for the Evaluation and Development of Novel Regenerative Therapies.

STUDY DESIGN: Large animal research. OBJECTIVE: Lumbar discectomy is the most commonly performed spinal surgical procedure. We investigated 2 large animal models of lumbar discectomy in order to study the regenerative capacity of mesenchymal stem cells following disc injury. METHODS: Twelve adult ewes underwent baseline 3-T magnetic resonance imaging (MRI) followed by lumbar intervertebral disc injury by either drill bit (n = 6) or annulotomy and partial nucleotomy (APN) (n = 6). Necropsies were performed 6 months later. Lumbar spines underwent 3-T and 9.4-T MRI prior to histological, morphological and biochemical analysis. RESULTS: Drill bit-injured (DBI) and APN-injured discs demonstrated increased Pfirrmann grades relative to uninjured controls (P < .005), with no difference between the 2 models. Disc height index loss was greater in the APN group compared with the DBI group (P < .005). Gross morphology injury scores were higher in APN than DBI discs (P < .05) and both were higher than controls (P < .005). Proteoglycan was reduced in the discs of both injury models relative to controls (P < .005), but lower in the APN group (P < .05). Total collagen of the APN group disc regions was higher than DBI and control discs (P < .05). Histology revealed more matrix degeneration, vascular infiltration, and granulation in the APN model. CONCLUSION: Although both models produced disc degeneration, the APN model better replicated the pathobiology of human discs postdiscectomy. We therefore concluded that the APN model was a more appropriate model for the investigation of the regenerative capacity of mesenchymal stem cells administered postdiscectomy.

Mesenchymal progenitor cells primed with pentosan polysulfate promote lumbar intervertebral disc regeneration in an ovine model of microdiscectomy.

BACKGROUND CONTEXT: Neural compression associated with lumbar disc herniation is usually managed surgically by microdiscectomy. However, 10%-20% of patients re-present with debilitating back pain, and approximately 15% require further surgery. PURPOSE: Using an ovine model of microdiscectomy, the present study investigated the relative potential of pentosan polysulfate-primed mesenchymal progenitor cells (pMPCs) or MPC alone implanted into the lesion site to facilitate disc recovery. STUDY DESIGN: An ovine model of lumbar microdiscectomy was used to compare the relative outcomes of administering MPCs or pMPCs to the injury site postsurgery. METHODS: At baseline 3T magnetic resonance imaging (MRI) of 18 adult ewes was undertaken followed by annular microdiscectomy at two lumbar disc levels. Sheep were randomized into three groups (n=6). The injured controls received no further treatment. Defects of the treated groups were implanted with a collagen sponge and MPC (5×105 cells) or pMPC (5×105 cells). After 6 months, 3T MRI and standard radiography were performed. Spinal columns were dissected, individual lumbar discs were sectioned horizontally, and nucleus pulposus (NP) and annulus fibrosus (AF) regions were assessed morphologically and histologically. The NP and AF tissues were dissected into six regions and analyzed biochemically for their proteoglycans (PGs), collagen, and DNA content. RESULTS: Both the MPC- and pMPC-injected groups exhibited less reduction in disc height (p<.05) and lower Pfirrmann grades (p≤.001) compared with the untreated injury controls, but morphologic scores for the pMPC-injected discs were lower (p<.05). The PG content of the AF injury site region (AF1) of pMPC discs was higher than MPC and injury control AF1 (p<.05). At the AF1 and contralateral AF2 regions, the DNA content of pMPC discs was significantly lower than injured control discs and MPC-injected discs. Histologic and birefringent microscopy revealed increased structural organization and reduced degeneration in pMPC discs compared with MPC and the injured controls. CONCLUSIONS: In an ovine model 6 months after administration of pMPCs to the injury site disc PG content and matrix organization were improved relative to controls, suggesting pMPCs' potential as a postsurgical adjunct for limiting progression of disc degeneration after microdiscectomy.

Spontaneous peritoneal catheter knot formation: A rare cause of ventriculoperitoneal shunt malfunction.

Ventriculoperitoneal (VP) shunting remains invaluable in the management of hydrocephalus. It is a common procedure that can be complicated by shunt malfunction due to infection, blockage and disconnection. Spontaneous peritoneal catheter knot formation causing CSF flow obstruction is a rare phenomenon. We present a case of a 12years old boy with spontaneous knot formation in the peritoneal catheter causing VP shunt obstruction and hydrocephalus.

Neurotropic cutaneous malignant melanoma with contiguous spread to spinal cord, an extremely rare presentation.

Neurotropic melanoma (NM) is a rare variant of cutaneous melanomas. Compared with conventional melanoma, NM is more locally aggressive with an increased tendency for local recurrence but less likely for nodal or distant metastases. The often amelanotic, benign appearance may lead to treatment issues such as late presentation, diagnostic delay, misdiagnosis, insufficient surgical margins, and recurrence with resulting poor outcome. To our knowledge, this is the first case report of NM with contiguous spread to the spinal cord. We present a case report of a 73-year-old male with gradual decline in mobility over the period of few months. He deteriorated very rapidly whilst inpatient with progressive myelopathy, loss of sphincter function and dysphonia with dysphagia due to involvement of lower cranial nerves. The neurotropic nature of the disease and prevalence in the head and neck region results in perineural and neural invasion with resulting neuropathies. Patient underwent posterior cervical decompression and resection of the higher cervical intramedullary spinal cord NM lesion. He recovered well with improvement of his limb weakness as well as bulbar function. Wide local excision (WLE) with adjuvant radiotherapy where indicated remains the current practice for treatment, with chemotherapy predominately being reserved as a salvage treatment for patients with disseminated disease.

Successful treatment of negative pressure hydrocephalus using timely titrated external ventricular drainage: a case series.

OBJECTIVE: Negative-pressure hydrocephalus (NegPH) is a rare clinical entity characterised by enlarged ventricles and symptoms consistent with increased intracranial pressure (ICP) in the setting of negative ICP. Little has been published regarding appropriate treatment and outcomes of negative-pressure hydrocephalus patients, and no data have been published demonstrating successful therapy producing acceptable long-term outcomes. Here we present 8 cases successfully treated by titrated external ventricular drainage (TEVD), including drainage at negative (subatmospheric) pressure, and subsequent low-pressure ventriculoperitoneal shunting. METHODS: A retrospective audit of all cases of negative-pressure hydrocephalus occurring at a university teaching hospital between 2006 and 2012 was undertaken. The clinical features of these cases, results of radiological investigations, treatment, and outcome were drawn from the patients' records. RESULTS: Eight cases of NegPH were identified. All patients had at least one preceding intracranial procedure (mean number of procedures 3.0). All cases were treated using TEVD, titrated to produce between 5 and 15 mL per hour of CSF drainage, including drainage under subatmospheric pressure if this was required to maintain CSF flow. Mean delay from first negative ICP to TEVD was 1.8 days. All 8 patients demonstrated clinical improvement. TEVD resulted in improvement in Glasgow Coma Scale (mean increase 4.6, p=0.003), and increases in ICP (mean increase 8.5, p<0.001). Mean length of follow-up was 471.8 days. At follow-up, four patients had returned to pre-morbid functioning, three had a reduction in functioning attributable to their initial presentation (not NegPH), and one had died of unknown cause. Illustrative case descriptions are included. CONCLUSIONS: Negative-pressure hydrocephalus is a rare but underrecognised syndrome that can be successfully treated by timely external ventricular drainage titrated to maintain CSF flow, and subsequent low-pressure ventriculoperitoneal shunting.