K. Schmieder

3-Dimensional computed tomographic angiography for use of surgery planning in patients with intracranial aneurysms

SummaryBackground. After subarachnoid haemorrhage (SAH) diagnostic evaluation of the underlying cause is warranted since the rebleeding rate is high. The objective of the study was to answer the question, whether 3-Dimensional computed tomographic angiography (3D-CTA) is able to accurately determine the surgical indications in patients with intracranial aneurysms.Methods. After performing 3D-CTA the size of the aneurysm, direction of the aneurysmal dome, neck position and variants of the circle of Willis were analysed. Surgery was performed solely on CTA data in those cases, where the aneurysm was clearly visible. If the findings were negative or inconclusive, intra-arterial digital subtraction angiography (DSA) was also done.Findings. Between January 2001 and December 2002 100 patients (68u2009F, 32u2009M) were examined and 123 aneurysms (86 ruptured and 37 unruptured) were diagnosed. All patients received CTA preoperatively and in 27 patients selective DSA was additionally performed. Postoperatively in 34 patients the operative result was checked by DSA.A good correlation between CTA and the intra-operative findings was present in 92 of 100 patients. One aneurysm was not seen on CTA, but was on DSA. In four cases we could confirm DSA findings in CTA after re-evaluation of the data. In three cases neither CTA nor DSA clearly showed an aneurysm, but it was confirmed during surgery.A good correlation between CTA and DSA was found in 60 of 61 patients (98%). The correlation between CTA and intra-operative findings was good as expected in 92 patients, in 5 patients an aneurysm was detected on re-evaluation. Only one aneurysm could not be demonstrated by CTA but in DSA.Conclusion. CTA is less invasive, less time consuming, cheaper and easier to demonstrate the essential information regarding the aneurysm than DSA. We therefore recommend that following a careful analysis most aneurysms – 92% – can be operated solely on CTA data.

Computed tomographic angiography in the evaluation of clip placement for intracranial aneurysm

SummaryBackground. Computed tomographic angiography (CTA) has been shown to reliably detect aneurysms pre-operatively. The aim of this study was to compare the ability of post-operative CTA to detect aneurysmal remnants in connection with clip placement compared with digital subtraction angiography (DSA). Furthermore, special attention was paid to identifying factors influencing the image quality of CTA.n Method. Between January 2005 and January 2006 a total of 76 patients with intracranial aneurysms were treated in our department. Thirty-two patients with a total of 33 clipped aneurysm were included in this study. All patients underwent CTA and DSA after surgery. Two investigators, each blinded to the classifications of the other, assessed image quality and clip placement.n Findings. In three patients aneurysmal remnants could be detected with CTA and DSA. One 2-mm aneurysmal remnant was not clearly identified on CTA; two small (<2-mm) aneurysmal remnants were definitely not seen on CTA. A single titanium clip was used for aneurysmal clipping in 26 patients, two clips were needed in six patients and one aneurysm required three clips being used. Overall, use of one titanium clip tended to result in better image quality. In addition, clip-gantry angles between 30° and 60° tended to yield better image quality.n Conclusion. Post-operatively, CTA can be recommended as a reliable non-invasive diagnostic tool only with optimal image quality and with this criterion up to 66% of the aneurysms can be evaluated. Titanium artefacts, especially in the important zone (<2u2009mm) around the clip in which small aneurysmal remnants can occur, can render adequate evaluation impossible. CTA image quality depends on the number of titanium clips used, but clip-gantry-angle does not significantly influence the image quality.

Chronic subdural haematoma in patients with Huntington's disease

We studied the frequency of patients who had chronic subdural haematomas (CSDH) and Huntingtons disease (HD) in a 1-year study period. In our department a total of 58 patients with CSDH were treated. Four patients (6.9% of them) had HD. Surgical evacuation of the haematoma was performed in all four cases with the use of a twist drill trepanation without a drainage system.

Treatment of degenerative cervical disc disease with uncoforaminotomy--intermediate clinical outcome.

BACKGROUNDnAnterior cervical uncoforaminotomy (uncoforaminotomy) is an operative method intended to preserve the functional motion segment of the cervical spine while removing the underlying pathology. Controversy exists concerning the patients best suited for this treatment modality. Furthermore, no long-term outcome analyses have been published.nnnMETHODSnBetween November 2002 and June 2004, 96 patients underwent single-level uncoforaminotomy in our neurosurgical department for the treatment of cervical radiculopathy. The patients were divided into three groups: A, soft disc; B, hard disc; C, hard and soft disc. Follow-up was performed 2 years after surgery. Clinical outcome was classified according to Odom et al. and to the cervical Oswestry and 11-point box scales for arm and neck pain.nnnRESULTSnNinety patients (92%) underwent intermediate follow-up examinations at an average of 33 months after surgery. Forty-nine patients were in group A, 24 in group B, and 17 in group C. At discharge, 98% of those in group A, 96% in group B, and 94% in group C showed excellent or good results. In two patients revision surgery was performed within 4 weeks due to recurrent disc herniation. In one patient revision was carried out due to a subcutaneous hematoma. In group B one case of vertebral artery injury occurred. Additionally in one patient of this group revision surgery was performed due to inadequate decompression of the neural foramen. At follow-up 94% of the patients in group A, 89% in group B, and 87% in group C had excellent or good results. The scores on the cervical Oswestry scale and the 11-point-box scale showed no significant differences among the groups.nnnCONCLUSIONnUncoforaminotomy, especially in patients with soft-disc pathologies, is a good operative method for the treatment of radicular pain.

Patient characteristics support unfavorable psychiatric outcome after treatment of unruptured intracranial aneurysms

IntroductionPrevious studies demonstrated an unfavorable psychological outcome after treatment of unruptured intracranial aneurysms despite an objectively favorable clinical and radiological outcome. The current study was therefore designed to analyze the psychiatric vulnerability of this specific patient collective.Materials and methodsPatients treated for a WHO grade I meningioma and incidental intracranial aneurysms in two German neurosurgical centers between 2007 and 2013 were screened for exclusion criteria including malignant/chronic diseases, recurrence of the tumor/aneurysm after more than 12xa0months and focal neurological deficits, among others. Seventy-five meningioma patients (M) and 56 incidental aneurysm patients (iA) met the inclusion criteria. The past medical psychiatric history, post-morbid personality characters and coping strategies were determined by questionnaires mailed to the patients in a printed version (Brief COPE, Big Five Personality Test).ResultsFifty-eightxa0M and 45 iA patients returned the questionnaires. Patients with iA demonstrated significantly higher pre-interventional rates of depressive episodes (pu2009=u20090.002) and psychological supervision (pu2009=u20090.038). These findings were especially aggravated in iA patients who received their cranial imaging for unspecific symptoms such as dizziness, headaches or tinnitus (nu2009=u200933, history of depressions: 39.4xa0%; previous psychological supervision: 33.3xa0%). Furthermore, the analysis of the Big Five personality traits revealed remarkably elevated neuroticism scores in the iA collective.ConclusionThe current study demonstrates an increased rate of positive pre-interventional psychiatric histories in the iA collective. Although those patients represent only a small subgroup, they still may play an important role concerning the overall outcome after iA treatment. Early detection and psychological support in this subgroup might help to improve the overall outcome. Further studies are needed to evaluate the influence of this new aspect on the multifactorial etiology of unfavorable psychiatric outcome after treatment of iA.

Consideration of ergonomic aspects in the development of a new endoscopic navigation system

During the development of new navigation systems, the ergonomic aspects of the accompanying software are seldom taken into account. The VN system is a navigation system working with real and previously stored neuroendoscopic images. The latter enable the module to execute virtual back movement, e.g. in case of bleeding. Several other modules are offered. The aim of the study was the ergonomic analysis of different modules and their learning curves in cadaveric heads. The endoscope was navigated by the neurosurgeon while another person operated the computer. A total of 128 experiments were performed with two software versions. When the landmark tracking module was used, a real learning curve could be observed. By contrast, testing the measurement module did not produce a learning curve. A significant reduction of the time required by the three modules investigated could be observed with software version 2. The module for virtual back movement works best with a minimum time of 20 s for image storage. During machine-human interactions ergonomic software use is important, especially if operative procedures are performed.

One-step CAD/CAM titanium cranioplasty after drilling template-assisted resection of intraosseous skull base meningioma: technical note

IntroductionCranial defects following intra-osseous tumor removal may be large and require adequate reconstruction. CAD/CAM implants have been used for years to achieve an optimal cosmetic result. The disadvantage is that such implants require a second surgery. A preoperative virtual planning of resection margins and the simultaneously fabrication of the cranioplasty could be a possibility to subsume the steps tumor resection and cosmetic restoration to a single procedure.MethodsWe present two cases of patients with complex intra-osseous spheno-orbital meningioma. Tumor resection was performed with the help of a drilling template in form of a frame. The template also served as a negative for the computer-designed cranioplasty. The devices were manufactured by DMD GmbH – Digital Medical Design/DDI-Group, Dortmund, Germany.DiscussionThe usage of the template was highly practicable. Small adjustments in bone removal were necessary to achieve an optimal fitting of the implant. The 6-month follow-up showed for one patient a good and for one a satisfactory cosmetic result. No second surgery was necessary.ConclusionsDrilling template application could contribute to challenging cases of large fronto-basal meningiomas with the aim of minimizing operation time and achieving a good esthetic outcome.

Deep venous thrombosis after lumbar disc surgery due to compression of the vena cava caused by a retroperitoneal haematoma

The case of a 46-year-old Arabian male complaining of low back pain due to congenital lumbar spinal canal stenosis with additional disc herniation is presented. Following CT scan and MRI, bilateral enlarged partial hemilaminectomy was performed in L5/S1 with removal of herniated disc material. Intraoperatively, no complication was encountered. In the postoperative course, the patient had persistent low back pain and developed deep venous thrombosis in the left leg. Phlebography revealed thrombosis in the deep veins of the left leg extending into the pelvic region. The source of this high obstruction of the venous outflow was a retroperitoneal haematoma, visible on CT scan, compressing the vena cava at the level of L5/S1, the most probable cause of which was accidental perforation of the anterior spinal ligament. This case demonstrates that injury to the retroperitoneal vessels during lumbar disc surgery can also present as deep venous thrombosis due to obstruction of venous outflow.

An optical evaluation of the phenomenon of red out in neuroendoscopic surgery: what is the physical background?

BackgroundThe loss of visualization in neuroendoscopy due to intraoperative bleeding is called “red out”. Although red out is a well-known problem during endoscopy, clear physical descriptions of this phenomenon are lacking.ObjectiveThe aim of this study was to investigate the optical properties of red out. In particular, the attenuation coefficient, comprising scattering, and absorption, of various blood/Ringer solutions was quantified and measured spectrally resolved. Small amounts of blood virtually preclude neuroendoscopic visualization. In blood/Ringer solutions with a dilution of 1:101, it was not possible to distinguish characters (font size 10, Arial) at a distance of 5xa0mm. We have concluded, from our physical investigations, that the problem of red out is dominated by scattering rather than by absorption. Accordingly, technical developments aimed at increasing information acquisition under red out conditions should be based on optical measurement concepts for scattering media.

Cerebral vascular reactivity response to anaesthetic induction with propofol in patients with intracranial space-occupying lesions and vascular malformations.

Background and objective: In clinical trials, autoregulation and carbon dioxide reactivity are preserved during propofol anaesthesia. Paradoxical increases of blood flow velocity during induction of anaesthesia could be demonstrated in patients with brain tumours. This study evaluates the effects of propofol on cerebral blood flow velocity in patients undergoing surgery for brain tumours and vascular malformations. Methods: Changes in cerebral blood flow velocity after the administration of propofol were assessed using bilateral 2 MHz transcranial Doppler probes in 47 patients undergoing surgery for brain tumours and in 22 patients undergoing surgery for aneurysms and angiomas. Results: Flow reduction after propofol was slightly less pronounced on the side of the tumour; in patients with cerebrovascular lesions, no difference between the two sides was detectable. After the administration of propofol a flow increase was present on the side of the tumour in 2 patients. In 3 patients with angiomas, the flow decrease after the administration of propofol was less pronounced on the side of the angioma. Neither observation gave statistical proof of abnormality. Conclusions: The flow changes after propofol may give a hint of cerebrovascular reactivity. Further investigations should focus on combined measurements of cerebral autoregulation and carbon dioxide reactivity and should focus on patients with impaired consciousness to test for reliability.