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Clip ligation of unruptured intracranial aneurysms: a prospective midterm outcome study

Acta Neurochir (2012) 154:1135–1144. DOI 10.1007/s00701-012-1397-y

We conducted a prospective study to investigate the clinical and radiological outcome in a surgical case series of 176 patients with 203 unruptured intracranial aneurysms (UIA).

Methods The success of aneurysm obliteration was assessed within 2 weeks after surgery by digital subtraction angiography (DSA). Patients also underwent angiography 5 years after surgery. Clinical outcomes were assessed using the modified Rankin Scale (mRS). All predictors of poor surgical outcomes were assessed using an exact logistic regression.

Results Overall, 83%of the patients had a good outcome (mRS score 0 or 1); 10.8 % of the patients had a slight disability (mRS score 2), and 6.2 % of the patients had a moderate or moderatesevere disability (mRS score 3 or 4). The mortality rate was 0% overall. The most important predictors of outcome were presence of history of ischemic cerebrovascular disease and postoperative stroke. Complete aneurysm occlusion was achieved in 93.5 % of all aneurysms. Sixty percent of treated aneurysms were checked with late follow-up DSA. No cases of hemorrhage from a surgically obliterated UIA were documented in this series during the 7.3±1.4 (SD)-year follow-up period.

Conclusions If patients are carefully selected and individually assigned to their optimum treatment modality, IUAs can be obliterated by surgery with a low percentage of unfavorable outcomes.

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Giant Invasive Spinal Schwannoma: Its Clinical Features and Surgical Management

Neurosurgery 71:58–67, 2012 DOI: 10.1227/NEU.0b013e31824f4f96

Giant invasive spinal schwannoma (GISS) is defined as a lesion that extends over . 2 vertebral levels, erodes vertebral bodies, and extends posteriorly and laterally into the myofascial planes. Because of its rarity, few reports have been issued.

OBJECTIVE: To analyze the clinical features and outcomes of GISS and to discuss surgical strategies.

METHODS: We analyzed the medical records, pathological findings, and radiographic studies of patients with GISS.

RESULTS: Fourteen patients with GISS were surgically treated between 2002 and 2007. Five lesions were in the sacral region, 4 in the lumbosacral, 2 in the thoracolumbar, and 1 each in the cervical, cervicothoracic, and thoracic regions. Gross total resection was performed in 11 of the 14 patients. Satisfactory decompression was performed in all patients for neural compression. Postoperatively, all patients showed relief of pre- operative pain and paresthesia. The growth potential with the Ki-67 index was . 2% in 6 patients, and 4 of them experienced tumor regrowth or recurrence. All patients were followed up for at least 24 months. Final follow-up magnetic resonance images showed asymptomatic small tumor recurrence on the sacrum in 2 patients. Two patients required spinal stabilization. No instability was found on follow-up.

CONCLUSION: Total resection is the treatment of choice for patients with GISS and provides functional improvements, low permanent morbidity, and a low rate of recurrence. Total resection of the intraspinal portion and regular follow-up with con- sideration of the Ki-67 index is recommended when total resection is not achieved.

 

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Comparison of Infection Rate With the Use of Antibiotic-Impregnated vs Standard Extraventricular Drainage Devices: A Prospective, Randomized Controlled Trial

Neurosurgery 71:6–13, 2012 DOI: 10.1227/NEU.0b013e3182544e31

External ventricular drainage (EVD) catheters provide reliable and accurate means of monitoring intracranial pressure and alleviating elevated pressures via drainage of cerebrospinal fluid (CSF). CSF infections occur in approximately 9% of patients. Antibiotic-impregnated (AI) EVD catheters were developed with the goal of reducing the occurrence of EVD catheter-related CSF infections and their associated complications.

OBJECTIVE: To present an international, prospective, randomized, open-label trial to evaluate infection incidence of AI vs standard EVD catheters.

METHODS: Infection was defined as (1) proven infection, positive CSF culture and positive Gram stain or (2) suspected infection: (A) positive CSF culture with no organisms identified on initial Gram stain; (B) negative CSF culture with a gram-positive or -negative stain; (C) CSF leukocytosis with a white blood cell/red blood cell count .0.02.

RESULTS: Four hundred thirty-four patients underwent implantation of an EVD catheter. One hundred seventy-six patients in the AI-EVD cohort and 181 in the standard EVD catheter cohort were eligible for evaluation of infection. The 2 groups were similar in all clinical characteristics. Proven infection was documented in 9 (2.5%) patients (AI: 4 [2.3%] vs standard: 5 [2.8%], P = 1.0). Suspected infection was documented in 31 (17.6%) patients receiving AI and 37 (20.4%) patients receiving standard EVD catheters, P = .504. Duration of time to suspected infection was prolonged in the AI cohort (8.8 6 6.1 days) compared with the standard EVD cohort (4.6 6 4.2 days), P = .002.

CONCLUSION: AI-EVD catheters were associated with an extremely low rate of catheter-related infections. AI catheters were not associated with risk reduction in EVD infection compared to standard catheters. Use of AI-EVD catheters is a safe option for a wide variety of patients requiring CSF drainage and monitoring, but the efficacy of AI-EVD catheters was not supported in this trial.

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Motion Preservation and Clinical Outcome of Porous Coated Motion Cervical Disk Arthroplasty

Neurosurgery 71:30–37, 2012 DOI: 10.1227/NEU.0b013e31824e512e

Artificial cervical disk replacements are commonly used to treat radiculomyelopathy caused by degenerative disk disease. However, long-term disk mobility and an effect on adjacent segment disease have yet to be demonstrated. We report improvements in clinical outcome after disk replacement but also demonstrate potential limitations.

OBJECTIVE: To review clinical and radiological outcomes after diskectomy and disk replacement with the Porous Coated Motion (PCM) artificial cervical disk.

METHODS: A retrospective review was done of consecutive patients who underwent 1- or 2-level PCM disk replacements. The following criteria were studied: arm pain, neck pain, Neck Disability Index and Short Form-36 questionnaires, and flexion-extension radiographs up to 2 years after surgery.

RESULTS: Eighty PCM artificial disks were implanted in 53 patients. Only 17 disks (21%) maintained physiological movement, and complete fusion was seen in 18.8%. One disk replacement was revised because of anterior displacement. There were no complications of infection, cerebrospinal fluid leak, dysphagia, or hoarse voice. Arm and neck pain improved significantly after diskectomy, but Neck Disability Index questionnaires demonstrated a slight improvement that was not sustained by 2 years. Short Form-36 scores demonstrated a trend toward better outcome with time, but it was significant only for the mental domain.

CONCLUSION: Clinical improvement was seen after PCM disk replacement, but adequate range of movement was sustained in only 21% of disk replacements over time. Unclear long-term results of this and other disk replacements suggest caution in adopting these new devices as the gold standard.

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Failure of Percutaneous Remodeling of the Ligamentum Flavum and Lamina for Neurogenic Claudication

Neurosurgery 71:86–92, 2012 DOI: 10.1227/NEU.0b013e31825356f5

Percutaneous remodeling of the ligamentum flavum and lamina (PRLL), commercially known as minimally invasive lumbar decompression (mild technique), relies on fluoroscopy and epidural contrast to direct surgical instruments via a 6-mm cannula.

OBJECTIVE: To evaluate the safety and efficacy of PRLL and present, to our knowledge, the first reported imaging findings after PRLL.

METHODS: We performed a prospective study of PRLL for neurogenic claudication. Primary outcomes were Oswestry Disability Index, Short-Form 12 version 2.0 health survey, and visual analog scale for pain at 26 weeks. Analgesic use was also assessed. Postoperative magnetic resonance imaging was performed at 12 weeks. Long-term failure, defined as the poststudy need for secondary surgery, was assessed up to 18 months.

RESULTS: Ten subjects with an average age of 64 years (range, 41-81 years) were treated between September 2008 and January 2009. There were no major adverse events. Mean postoperative visual analog scale score remained significantly reduced throughout 26 weeks (P =.015, analysis of variance). Mean postoperative Oswestry Disability Index was also improved by 1 week and remained significant throughout 26 weeks (P = .024; analysis of variance). However, there was a trend toward increased reliance on narcotic type medications postoperatively. Imaging studies did not show significant decompression of the spinal canal in any patient. In the poststudy period, recurrent claudication requiring laminectomy developed in 6 patients (60%).

CONCLUSION: Throughout 26 weeks, pain and disability scores were decreased; however, PRLL did not improve the degree of stenosis on imaging studies. Although PRLL appears to be safe in this small cohort of patients, poststudy outcomes indicate that the failure rate is unacceptably high.

 

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Optimized angiographic computed tomography with intravenous contrast injection: an alternative to conventional angiography in the follow-up of clipped aneurysms?

J Neurosurg 117:29–36, 2012

The purpose of this study was to evaluate the diagnostic accuracy of an optimized angiographic CT (ACT) program with intravenous contrast agent injection (ivACT) in the assessment of potential aneurysm remnants after neurosurgical clipping compared with conventional digital subtraction angiography (DSA).

Methods. The authors report on 14 patients with 19 surgically clipped cerebral aneurysms who were scheduled to undergo angiographic follow-up. For each patient, the authors performed ivACT with dual rotational acquisition and conventional angiography including a 3D rotational run. The ivACT and 3D DSA data were reconstructed with different imaging modes, including a newly implemented subtraction mode with motion correction. Thereafter, the data sets were merged by the dual-volume technique, and freely rotatable 3D images were obtained for further analysis. Observed aneurysm remnants were electronically measured and classified for each modality by 2 experienced neuroradiologists.

Results. Digital subtraction angiography and ivACT both provided high-quality images without motion artifacts. Artifact disturbances from the aneurysm clips led to a compromised, but still sufficient, image quality in 1 case. The ivACT assessed all aneurysm remnants as true-positive up to a minimal size of 2.6 × 2.4 mm in accordance with the DSA findings. There was a tendency for ivACT to overestimate the size of the aneurysm remnants. All cases without aneurysm remnants on DSA were scored correctly as true-negative by ivACT.

Conclusions. By using an optimized image acquisition protocol as well as enhanced postprocessing algorithms, the noninvasive ivACT seems to achieve results comparable to those of conventional angiography in the follow-up of clipped cerebral aneurysms. The authors have shown that ivACT can provide reliable diagnostic information about potential aneurysm remnants after neurosurgical clipping with high sensitivity and specificity, sufficient for clinical decision making, at least for aneurysms in the anterior circulation located distal to the internal carotid artery. These preliminary results may be a promising step to replace conventional angiography by a noninvasive imaging technique in selected cases after aneurysm clipping.

 

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Anterior Cervical Reconstruction With Pedicle Screws After a 4-Level Corpectomy

Spine 2012 ; 37 : E927 – E930

Anterior reconstruction after multilevel corpectomy is a challenging technique, and there are many reports on its complications. Graft dislodgement is one of the major complications after long cervical fusion. The main cause of failure seems to be a lack of stability in the conventional reconstruction technique. However, pedicle screws for posterior cervical reconstruction show remarkable stability. We describe a new technique of anterior cervical reconstruction with pedicle screws and fibular strut grafting.

Methods. Seven patients with multilevel cervical myelopathy were treated with this new reconstruction technique after a 4-level corpectomy. We describe this new technique and review the patients’ clinical history, results of radiographical imaging, and outcomes. Clinical outcomes were assessed preoperatively and at 3 months postoperatively. Postoperative radiographs were assessed 3 months and 6 months postoperatively.

Results. The mean operative time was 182 minutes and the mean blood loss was 271 mL. The average Japanese Orthopaedic Association score for cervical myelopathy improved from 11.5 points preoperatively to 14.5 points 3 months postoperatively. No patients experienced major complications, such as neurological deterioration, infection, or massive blood loss. There was no case of reconstruction failure, graft dislodgement, migration, or screw displacement.

Conclusion. To our knowledge, this is the first description of an anterior cervical reconstruction approach, using pedicle screws and fibular strut grafting after a 4-level corpectomy. It is likely that this technique will result in better clinical outcomes with fewer complications in the treatment of patients with multilevel cervical myelopathy.

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Intracellular Signaling Pathways and Size, Shape, and Rupture History of Human Intracranial Aneurysms

Neurosurgery 70:1565–1573, 2012 DOI: 10.1227/NEU.0b013e31824c057e

Size and morphological features are associated with intracranial aneurysm (IA) rupture. The cellular mechanisms of IA development and rupture are poorly known.
OBJECTIVE: We studied the expression and phosphorylation of different intracellular signaling molecules in the IA wall compared with IA morphological features to understand better the cellular pathways involved in IA development and wall degeneration.
METHODS: Nine ruptured and 17 unruptured human IA samples were collected intraoperatively. The expression levels and phosphorylation state of 3 mitogen-activated protein kinases (c-Jun N-terminal kinase [JNK], p38, extracellular signal-regulated kinase [ERK]), Bcl-2 antagonist of cell death (Bad), mammalian target of rapamycin (mTOR), cyclic AMP response element binding protein (CREB), and Akt were determined by Western blotting. The localization of signaling proteins was determined by immunofluorescence. From 3-dimensional segmentation of computed tomography angiographic data, size and shape indexes were calculated.
RESULTS: We found a 5-fold difference in phospho-Bad levels between ruptured and unruptured IAs. Phospho-mTOR was downregulated 2.5-fold in ruptured IAs. Phosphop54 JNK, phospho-p38, and phospho-Akt levels correlated positively with IA size. Phospho-CREB levels were significantly associated with nonsphericity and ellipticity indexes. Phospho-Akt and phospho-p38 correlated negatively with undulation index.
CONCLUSION: The signaling pathway profile (apoptosis, cell proliferation, stress signaling) differs between ruptured and unruptured IAs and is associated with IA geometry. Our results increase the knowledge of IA development and wall degeneration.

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Safe Resection of Arteriovenous Malformations in Eloquent Motor Areas Aided by Functional Imaging and Intraoperative Monitoring

Neurosurgery 70[ONS Suppl 2]:ons276–ons289, 2012. DOI: 10.1227/NEU.0b013e318237aac5

Arteriovenous malformations (AVMs) proximal to motor cortical areas or motor projection systems are challenging to manage because of the risk of severe sensory and motor impairment. Surgical indication in these cases therefore remains controversial.
OBJECTIVE: To propose a standardized approach for centrally situated AVMs based on functional imaging and intraoperative electrophysiological evaluation.
METHODS: We conducted a retrospective analysis of 15 patients who underwent surgical treatment for AVMs in motor cortical areas or proximal to motor projections. Preoperative assessment included functional magnetic resonance and 3-dimensional tractography. Operations were performed under continuous electrophysiological monitoring aided by direct brain stimulation. We identified critical bloody supply to the motor areas by temporary occluding the feeding vessels under electrophysiological monitoring. Clinical outcome was evaluated with the modified Rankin Scale.
RESULTS: Total resection was achieved in 12 cases, whereas electrophysiology limited total extirpation in 3 cases. A significant reduction of motor evoked potentials by up to 15% of the initial values was associated with good recovery of motor function; in contrast, the disappearance of potentials correlated with long-term impairment. The mean follow-up time was 13 months, and clinical assessments revealed overall functional improvement (P , .05). After surgery, 11 patients were asymptomatic or presented with only minor neurological deficits.
CONCLUSION: Surgical resection of AVMs in eloquent motor areas can be considered a safe option for selected cases when performed in conjunction with a detailed functional assessment. Possible selection criteria for surgical treatment are discussed in light of the presented clinical data.

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Factors predicting retreatment and residual aneurysms at 1 year after endovascular coiling for ruptured cerebral aneurysms: Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) in Japan

Neuroradiology (2012) 54:597–606. DOI 10.1007/s00234-011-0945-0

Endovascular treatment of cerebral aneurysms includes follow-up imaging to identify aneurysms that may need retreatment. The aim of this study was to determine predictors of incomplete aneurysm occlusion at 1 year after endovascular coiling for ruptured cerebral aneurysms.
Methods In 129 patients of the Prospective Registry of Subarachnoid Aneurysms Treatment cohort, ruptured aneurysms were coiled within 14 days of onset and both initial post-coiling and 1-year follow-up digital subtraction angiography or magnetic resonance angiography were obtained. Factors predicting 1-year incomplete aneurysm occlusion (retreatment within 1-year or residual aneurysms at 1 year) were determined using multivariate logistic regression analyses.
Results One-year incomplete aneurysm occlusion was identified in 59 patients, including ten patients who were retreated within 1-year post-coiling. Dome size ≥7.5 mm (P=0.007, odds ratio (OR)=5.00, 95% confidence interval (CI)=1.55– 16.15), pre-treatment aneurysm re-rupture (P=0.023, OR= 3.50, 95% CI=1.19–10.31), non-small size/small neck aneurysm (dome size, ≥10 mm or neck size, ≥4 mm; P= 0.022, OR=3.26, 95% CI=1.19–8.96), and residual aneurysms on immediate post-coiling angiograms (P=0.017, OR= 1.43, 95% CI=1.07–1.93) significantly predicted incomplete aneurysm occlusion at 1-year post-coiling.
Conclusions In addition to the characteristics of aneurysm and initially incomplete aneurysm occlusion, this study showed pre-treatment aneurysm re-rupture to be a predictor that favors closer imaging follow-ups for coiled aneurysms.

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Surgical nuances for nasoseptal flap reconstruction of cranial base defects with high-flow cerebrospinal fluid leaks after endoscopic skull base surgery

Neurosurg Focus 32 (6):E7, 2012. DOI: 10.3171/2012.5.FOCUS1255

Extended endoscopic endonasal approaches have allowed for a minimally invasive solution for removal of a variety of ventral skull base lesions, including intradural tumors. Depending on the location of the pathological entity, various types of surgical corridors are used, such as transcribriform, transplanum transtuberculum, transsellar, transclival, and transodontoid approaches. Often, a large skull base dural defect with a high-flow CSF leak is created after endoscopic skull base surgery. Successful reconstruction of the cranial base defect is paramount to separate the intracranial contents from the paranasal sinus contents and to prevent postoperative CSF leakage. The vascularized pedicled nasoseptal flap (PNSF) has become the workhorse for cranial base reconstruction after endoscopic skull base surgery, dramatically reducing the rate of postoperative CSF leakage since its implementation.

In this report, the authors review the surgical technique and describe the operative nuances and lessons learned for successful multilayered PNSF reconstruction of cranial base defects with high-flow CSF leaks created after endoscopic skull base surgery. The authors specifically highlight important surgical pearls that are critical for successful PNSF reconstruction, including target-specific flap design and harvesting, pedicle preservation, preparation of bony defect and graft site to optimize flap adherence, multilayered closure technique, maximization of the reach of the flap, final flap positioning, and proper bolstering and buttressing of the PNSF to prevent flap dehiscence. Using this technique in 93 patients, the authors’ overall postoperative CSF leak rate was 3.2%.

An illustrative intraoperative video demonstrating the reconstruction technique is also presented.

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Endoscopy in Aneurysm Surgery

Neurosurgery 70[ONS Suppl 2]:ons184–ons191, 2012. DOI: 10.1227/NEU.0b013e3182376a36

Surgical clipping with complete occlusion of the aneurysm and preservation of parent, branching, and perforating vessels remains the most definitive treatment for intracranial aneurysms.

OBJECTIVE: To evaluate the benefit of endoscopic application during microsurgical procedures in a retrospective study.

METHODS: One hundred eighty aneurysms were microsurgically treated in 124 operations. Three different applications of endoscopic visualization were used, depending on the respective requirements: inspection before clipping, clipping under endoscopic view, and postclipping evaluation.

RESULTS: Of 1380 aneurysms, 292 procedures were done with application of the endoscope. Of these 292, a complete data set, including video recording of the procedures for retrospective evaluation, was available in 180 cases. In these, the endoscope provided a favorable enhancement of the visual field, particularly in complex or deepseated lesions. No adverse effects were observed. Before clipping, the endoscope was used to gain additional topographic information in 150 of 180 cases (83%). Clipping under endoscopic view was performed in 4 cases. After clipping, endoscopic inspection was performed in 130 of 180 procedures. Depending on the endoscopic findings, rearrangement of the applied clip or additional clipping was found to be necessary in 26 of 130 cases (20.0%).

CONCLUSION: Endoscopic enhancement of the visual field provided by the endoscope before, during, and after microsurgical aneurysm occlusion may be a safe and effective application to increase the quality of treatment. Although unexpected findings concerning completeness of aneurysm occlusion and compromise of involved vessels could be diminished by endoscopic assessment, total prevention was not accomplished.

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Differences between 1- and 2-level cervical arthroplasty

J Neurosurg Spine 16:594–600, 2012. (http://thejns.org/doi/abs/10.3171/2012.2.SPINE111066)

The most currently accepted indication for cervical arthroplasty is 1- or 2-level degenerative disc disease (DDD) refractory to medical treatment. However, the randomized and controlled clinical trials by the US FDA investigational device exemption studies only compared cervical arthroplasty with anterior cervical discectomy and fusion for 1-level disease. Theoretically, 2-level cervical spondylosis usually implicates more advanced degeneration, whereas the 1-level DDD can be caused by merely a soft-disc herniation. This study aimed to investigate the differences between 1- and 2-level cervical arthroplasty.

Methods. The authors analyzed data obtained in 87 consecutive patients who underwent 1- or 2-level cervical arthroplasty with Bryan disc. The patients were divided into the 1-level and the 2-level treatment groups. Clinical outcomes were measured using the visual analog scale (VAS) for the neck and arm pain and the Neck Disability Index (NDI), with a minimum follow-up of 30 months. Radiographic outcomes were evaluated on both radiographs and CT scans.

Results. The study analyzed 98 levels of Bryan cervical arthroplasty in 70 patients (80.5%) who completed the evaluations in a mean follow-up period of 46.21 ± 9.85 months. There were 22 females (31.4%) and 48 males (68.6%), whose mean age was 46.57 ± 10.07 years at the time of surgery. The 1-level group had 42 patients (60.0%), while the 2-level group had 28 patients (40.0%). Patients in the 1-level group were younger than those in the 2-level group (mean 45.00 vs 48.93 years, p = 0.111 [not significant]). Proportional sex compositions and perioperative prescription of nonsteroidal antiinflammatory drugs were also similar in both groups (p = 0.227 and p = 1.000). The 2-level group had significantly greater EBL during surgery than the 1-level group (220.80 vs 111.89 ml, p = 0.024). Heterotopic ossification was identified more frequently in the 2-level group than the 1-level group (75.0% vs 40.5%, p = 0.009). Although most of the artificial discs remained mobile during the follow up, the 2-level group had fewer mobile discs (100% and 85.7%, p = 0.022) than the 1-level group. However, in both groups, the clinical outcomes measured by VAS for neck pain, VAS for arm pain, and NDI all significantly improved after surgery compared with that preoperatively, and there were no significant differences between the groups at any point of evaluation (that is, at 3, 6, 12, and 24 months after surgery).

Conclusions. Clinical outcomes of 1- and 2-level cervical arthroplasty were similar at 46 months after surgery, and patients in both groups had significantly improved compared with preoperative status. However, there was a significantly higher rate of heterotopic ossification formation and less mobility of the Bryan disc in patients who underwent 2-level arthroplasty. Although mobility to date has been maintained in the vast majority (94.3%) of patients, the long-term effects of heterotopic ossification warrant further investigation.

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Growing skull fracture stages and treatment strategy

J Neurosurg Pediatrics 9:670–675, 2012. (http://thejns.org/doi/abs/10.3171/2012.2.PEDS11538) 

A growing skull fracture (GSF) is a rare but significant late complication of skull fractures, usually occurring during infancy and early childhood. Delayed diagnosis and improper treatment could exacerbate this disease. The aim of this study was to introduce a new hypothesis about, describe the stages of, and discuss the treatment strategy for GSF.

Methods. The authors performed a retrospective review of 27 patients with GSF, who were grouped according to 3 different GSF stages.

Results. Over a period of 20 years, 27 patients with GSF (16 males and 11 females) were treated in the authors’ department. The mean follow-up period was 26.5 months. Six patients were in the prephase of GSF (Stage 1), 10 patients in the early phase (Stage 2), and 11 in the late phase (Stage 3). All patients underwent duraplasty. All 6 patients at Stage 1 and 5 patients at Stage 2 underwent craniotomy without cranioplasty. Five patients at Stage 2 and all of the patients at Stage 3 underwent cranioplasty with autologous bone and alloplastic materials, respectively. Among all patients, 5 underwent ventriculoperitoneal shunt placement. Symptoms in all patients at Stages 1 and 2 were alleviated or disappeared, and the cranial bones developed without deformity during follow-up. Among patients with Stage 3 GSF, no obvious improvement in neurological deficits was observed. Three patients underwent additional operations because of cranial deformation or infection.

Conclusions. The authors identify the stages of GSF according to a new hypothesis. They conclude that accurately diagnosing and treating GSF during Stages 1 and 2 leads to a better prognosis.

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Repair of middle fossa cerebrospinal fluid leaks using a novel combination of materials

Neurosurg Focus 32 (6):E8, 2012. (http://thejns.org/doi/abs/10.3171/2012.4.FOCUS1258)

Methods for repairing middle fossa CSF (MFCSF) leaks have varied and yielded mixed results. The objective of this study was to evaluate the safety and durability of the authors’ repair technique using a novel combination of 3 synthetic materials.

Methods. The authors performed a retrospective case review of patients treated for CSF leaks between January 2009 and September 2011. Eight patients were found to have undergone middle fossa craniotomies for CSF leaks. Inclusion criteria for the study included age greater than 18 years, neuroimaging-documented temporal bone defect, and symptoms consistent with CSF leaks or gross CSF otorrhea. Seven patients, 3 men and 4 women, met the inclusion criteria, and their charts were reviewed. Hydroxyapatite cement, collagen-based dural substitute matrix, and polyethylene glycol hydrogel sealant were used in all patients for the repair.

Results. In all patients the MFCSF leaks were successfully repaired. Initial presenting symptoms included CSF otorrhea in 4 patients (57.1%), hearing loss in 3 (42.9%), and CSF rhinorrhea in 1 (14.3%). The mean follow-up duration was 12 months (range 5–33 months). In 1 patient an epidural hematoma developed at the operative site on postoperative Day 2, and in another patient a superficial wound dehiscence occurred on postoperative Day 48. During the follow-up period, the authors found no evidence of wound infections, neurovascular damage, or CSF leakage requiring reoperation.

Conclusions. The middle fossa approach involving a combination of hydroxyapatite cement, collagen-based dural substitute matrix, and polyethylene glycol hydrogel sealant is a safe, effective method for repairing MFCSF leaks. The combination of synthetic materials provides an alternative to existing materials for skull base surgeons.

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Surgical technique for trigeminal microvascular decompression

Acta Neurochir (2012) 154:1089–1095 DOI 10.1007/s00701-012-1324-2

Microvascular decompression (MVD) is a non-ablative technique designed to resolve the neurovascular conflict responsible for typical idiopathic trigeminal neuralgia (TN).

Method With the patient in a supine position, a small elliptical retrosigmoid craniectomy is used to approach the cerebellopontine angle and the trigeminal nerve. After careful exploration of the trigeminal root entry zone, the offending vessel is identified and moved away. Oxidized regenerated cellulose is used to keep the vessel in its new position far from the nerve.

Conclusion MVD represents the gold standard first line treatment for TN; its aim is to free the nerve from any contact.

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Cerebral Bypasses for Complex Aneurysms and Tumors

Neurosurgery 70:1442–1457, 2012 DOI: 10.1227/NEU.0b013e31824c046f

Various techniques of cerebral bypasses are used to treat aneurysms and tumors.

OBJECTIVE: To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems.

METHODS: A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied.

RESULTS: A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1).

CONCLUSION: The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis.

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The Middle Fossa Approach and Extended Middle Fossa Approach: Technique and Operative Nuances

Neurosurgery 70[ONS Suppl 2]:ons192–ons201, 2012 DOI: 10.1227/NEU.0b013e31823583a1

The middle fossa approach and extended middle fossa approach, also known as the anterior transpetrosal approach, are cranial base techniques for addressing small vestibular schwannomas, medial temporal bone lesions, midbasilar trunk aneurysms, and selected petroclival lesions.

OBJECTIVE: To provide an outline of a number of technical nuances that are important to correct application of these approaches, maximizing exposure, and limiting potential morbidity.

METHODS: Via a temporal craniotomy, the petrous apex is removed in variable degrees, depending on the exposure requirements of the lesion. The technique is described in detail with appropriate nuances of the technique provided.

RESULTS: The described nuances of technique in the performance of the approaches have resulted in successful application of these techniques in a significant number of cases.

CONCLUSION: Significant familiarity and practice with these surgical approach techniques are critical to applying them safely to clinical problems. A number of technical details can assist the surgeon in achieving optimal exposure and limited morbidity.

 

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Surgical nuances for the endoscopic endonasal transpterygoid approach to lateral sphenoid sinus encephaloceles

Neurosurg Focus 32 (6):E5, 2012

Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions.

However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches. In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases.

The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.

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Direct Lateral Approach to Pathology at the Craniocervical Junction

Neurosurgery 70[ONS Suppl 2]:ons202–ons208, 2012 DOI: 10.1227/NEU.0b013e31824042e6

Approaches to the foramen magnum and upper cervical spine traditionally include the posterior midline, far lateral, and endoscopic endonasal approaches. The far lateral approach is a well-established technique for the removal of pathology ventrolateral to the brainstem and the craniocervical junction, but it may be too extensive for lesions limited to areas far from the midline.

OBJECTIVE: To present an alternative to the commonly used approaches to the foramen magnum and upper cervical.

METHODS: We used an approach directly overlying ventral or lateral pathology.

RESULTS: Two cases are presented in which the direct lateral approach followed by an occipitocervical fusion was successfully performed.

CONCLUSION: This approach can be considered for patients in whom a ventral decompression is necessary but an endoscopic endonasal approach is undesirable or when a ventral, lateral, and ventrolateral resection of tumor, pannus, or infection is required.

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