Uwe Spetzger

Management of complex cervical instability.

PURPOSE Illustrative cases are presented to demonstrate the surgical management of complex instability of the cervical spine. METHODS Six patients with different underlying pathologies are presented along with their clinical and radiologic findings, surgical procedures, complications, and outcomes. RESULTS Five patients underwent anteroposterior (AP) decompression and stabilization, of which two required secondary posterior stabilization because of dislocation or subsidence of the anterior osteosynthesis. In another case, a patient with a two-level corpectomy, a stable situation was achieved with an anterior approach only. The outcomes, measured according to Odoms criteria, were excellent in one patient, good in three patients, and fair in two patients. CONCLUSIONS In cases of complex cervical instability, combined AP decompression and stabilization minimizes the risk of anterior plate failure or dislocation of the vertebral body prosthesis. However, there may be increased risk of adjacent-level degeneration. Therefore, a combined procedure should be considered in selected patients. Not all patients with cervical instability require circumferential surgery. In two-level corpectomy cases, the decision between the less invasive anterior-only approach and the more stable combined approach can be difficult. However, in patients with proof of poor bone quality or with metabolic disorders, a more stable combined approach should be considered.

Surgical Treatment of Inadvertent Internal Carotid Artery Lesion by Extraintracranial High-flow Bypass. A Case Report and Review of the Literature

Internal carotid artery (ICA) injury following transsphenoidal surgery is a rare but potentially fatal complication. Usually, endovascular occlusion of the ICA or stent graft placement is the treatment of these vascular complications described in literature. We present a case of ICA perforation during transsphenoidal surgery in a patient with limited collateral cerebral blood flow and with ectasia of the ICA that rule out an endovascular treatment. We report the surgical revascularization via high-flow extra-intracranial radial artery bypass and consicutive artery ligation.

How Relevant Is Occlusion of Associated Developmental Venous Anomaly in Cerebral Cavernoma Surgery? A Clinical and Radiographic Comparison Study

BACKGROUND A developmental venous anomaly (DVA) associated with cerebral cavernous malformation (CCM) is the most common combined vascular malformation. Microsurgical resection of the CCM and avoidance of damage to the adjacent DVA is an overall accepted treatment regimen. Several publications have demonstrated serious consequences that possibly occur after damage of the associated DVA. Conversely, some authors have reported cases of injured DVAs without any relevant postoperative complications. This study compared the clinical and radiologic outcome in patients with and without occlusion of an associated DVA, following microsurgical removal of intracerebral cavernomas. METHODS In this single-center evaluation, all consecutive CCM surgical patients from January 1, 2006, to December 31, 2011, were reviewed in a retrospective cohort study. Follow-up was from 12 months to 7 years. The patients were divided into three groups: group I, CCM without associated DVA; group II, damage and occlusion of the associated DVA during CCM removal; and group III, preservation of the associated DVA following CCM removal. Preservation and damage, respectively, of the DVA were defined by evaluation of the corresponding pre- and postoperative magnetic resonance (MR) image sequences. The clinical and radiographic findings in all three groups were evaluated and compared. RESULTS A total of 38 patients underwent microsurgical resection of a CCM. Overall, 24 patients (63%) had no associated DVA (group I), in 10 patients (26%) the associated DVA was impaired and occluded (group II), and in 4 patients (11%) the associated DVA was surgically not impaired and confirmed as preserved (group III). The rate of postoperative neurologic deficits was 37.5% in group I, 10% in group II, and 75% in group III (p = 0.05). Subgroup analysis in patients with preserved DVA (group III) showed a higher incidence of new postoperative neurologic deficits than in patients with impaired DVA (group II) (p = 0.041). However, no significant difference was seen in patients with no associated DVA (group I) and patients with impaired DVA (group II) (p =0.215). The average postoperative Karnofsky score was 88.33 ± 9.17 in group I, 92.0 ± 6.32 in group II,; and 90.0 ± 8.16 in group III (p =0.51). The peri-resectional edema volume in group I was 8.90 ± 9.75 cm(3); in group II, 8.16 ± 3.78 cm(3); and in group III, 2.48 ± 1.48 cm(3) (p = 0.35). The location (eloquent or noneloquent region) of the CCM and the DVA, respectively, was the only significant factor for any additional neurologic deficit (p = 0.001). CONCLUSION Our results demonstrated similar postoperative clinical outcomes and radiographic findings between patients with impaired and unimpaired DVA after resection of CCMs. Postoperative MR images showed less peri-resectional edema in patients with preserved and unimpaired DVA. However, these results will not convert the paradigm in cavernoma surgery to preserve the associated DVA. The overall goal is still preservation of unimpaired venous drainage, but our results show that the occlusion of a DVA adjacent to a CCM can be tolerated because of a low risk of complications.

Surgery of the Skull Base

We may not be able to make you love reading, but surgery of the skull base will lead you to love reading starting from now. Book is the window to open the new world. The world that you want is in the better stage and level. World will always guide you to even the prestige stage of the life. You know, this is some of how reading will give you the kindness. In this case, more books you read more knowledge you know, but it can mean also the bore is full.

Tumors of the Skull Base

The big chapter about tumors of the skull base demonstrates the different aspects and neurosurgical techniques by renowned and very experienced skull base surgeons in a compact form. Due to the consecutive illustration with corresponding intraoperative photographic images, every single step of even complex surgical procedures can be reproduced and understood underlining the didactic value of the book. By means of the different tumor entities, the different surgical approaches including their advantages and disadvantages are demonstrated. The surgical and further strategies are explained from a practical point of view by using selected clinical cases as examples.

Vascular Lesions of the Skull Base

Cerebrovascular diseases of the skull base represent a separate entity. Especially aneurysms located close to the skull base as well as dural arteriovenous fistulas require highly specialized neuroradiological diagnostics and an individualized treatment strategy being exactly tailored to the lesion. For different reasons there has been a shift to endovascular treatment of these vascular lesions of the skull base over the years. Modern supraselective microcatheters and further development and improvement of the different embolization materials nowadays allow a very selective occlusion of arteriovenous malformations. Furthermore, the ongoing development of endovascular coil technology and especially the modern methods of vessel wall reconstruction by stents have pushed back the complex surgical procedures for the microsurgical clipping of skull base aneurysms. But nevertheless, endovascular procedures will not completely replace microsurgical therapy in the foreseeable future. A problem for the younger generation and especially for the practical training of young skull base surgeons is the decreasing number of neurovascular cases due to the increasing number of endovascular cases. Furthermore, often very complex cases that are very difficult to operate on remain for microsurgical therapy.

Preoperative Diagnostics and Indication for Surgery

Past medical history and clinical examination give information about radicular and myelopathic symptoms and help to assess the acuity of clinical complaints and thus the urgency of a possible surgical treatment. MRI is the imaging method of first choice in cases of degenerative diseases of the cervical spine with neurological symptoms. The meaning of pre- and postoperative functional X-ray imaging has continuously increased because of the growing number of dynamic implants for total disc replacement. With the help of CT scans especially bony driven stenoses of the cervical spinal canal can be diagnosed in detail. A myelogram is useful in selected cases of multilevel narrowing of the spinal canal, especially in cases of previous surgeries. If it is impossible to confirm or exclude the indication for surgery by means of clinical complaints and imaging findings, it might be useful to consider electrophysiological techniques for the clinical diagnosis.

The Future of Cervical Spine Surgery

On the basis of recent spine research, the manufacturing of individualised implants is possible. Using patient-specific computed tomography or magnetic resonance imaging data, an individual spine model can be rendered. With the help of such a model, an implant can be individually configured. Furthermore, it might be possible to test virtually the biomechanical behaviour of the cervical spine after implantation when using the finite element method. Another field of research is biological disc replacement by autologous transplantation of chondrocytes. At the thoracic and lumbar spines, the augmentation of screws with polymethylmethacrylate in cases of severe osteoporosis has been established for many years. Thus, this technique could be used for the cervical spine, too.

Choice of Surgical Approach

In most cases of degenerative diseases of the cervical spine, the neural structures are compressed from anterior; thus, the anterior approach is the mainly used surgical approach to the cervical spine. The posterior approach is suitable for findings with ligamentous hypertrophy and space-occupying facet joint arthrosis as well as for elderly patients with spontaneous bony fusion in the intervertebral spaces where as lordosis is an essential precondition for this approach. Combined approaches are indicated in cases of corpectomy of two or more vertebral bodies and generally in cases with reduced bone quality due to a metabolic diseases such as osteoporosis, diabetes mellitus or renal failure.

Implant Safety and Complication Management

In cases of secondary dislocation of disc or vertebral body replacements, it is usually necessary to perform an anterior and/or posterior fusion during revision surgery. Material failure of cervical implants is observed very rarely. Especially in cases of osteoporosis, secondary subsidence of disc or vertebral body replacements is not an unusual complication. The aimed maintenance of motion after the relatively expensive total disc replacement can be completely neutralised by heterotopic ossification. The latter is evoked by excessive drilling during primary surgery. The implant safety of cages and prostheses has been significantly improved by stop devices at the insertion instruments. Complications like accidental injuries of the dura, blood vessels, trachea or oesophagus are usually treated surgically.