Magnetic resonance imaging in the presence of projectiles and projectile fragments: Artefacts, image quality, rotation and movement.

BACKGROUND AND PURPOSE: Gunshot injuries have been considered a contraindication for MRI because of the risk of secondary dislodgement of retained metallic foreign bodies. The objective of our study was to provide a systematic overview of the behaviour of projectiles and fragments in order to aid decision-making regarding the use of MRI in clinical practice. MATERIALS AND METHODS: Ferromagnetic (n = 2) and non-ferromagnetic (n = 5) projectiles and fragments that were lodged in soft tissue (porcine masseter muscles) were examined using standard protocols at 1, 1.5 and 3 T, to simulate clinical situations as realistically as possible. CT was performed before and after every MRI to assess rotation and movement. Artefacts and image quality were analysed using Likert-type scales. RESULTS: Ferromagnetic projectiles were of poorer quality and showed larger artefacts and did not provide benefit for clinical practice compared to images of non-ferromagnetic material. Image quality of non-ferromagnetic projectiles varied widely (from very good to moderate) depending on the composition of the projectiles. Field strength (1 T to 3 T) had no relevant influence on image quality. CONCLUSIONS: Non-ferromagnetic projectiles are not a contraindication for MR imaging since there is no potential risk of secondary dislodgement. Image quality and the extent of artefacts, however, strongly depend on the type of ammunition used. The presence of ferromagnetic projectiles in or near vital anatomic structures is a contraindication for MRI because these objects may exhibit movement in response to magnetic fields. Knowledge of the type of projectile used appears to be important in order to guide patient management before an examination is performed. So, the production and use of projectiles suitable for MRI should be favored in the future, knowing that this will be hard to fulfil.

[Cavernomas of the central nervous system : Observational study of 111 patients]. / Kavernome des Zentralnervensystems : Verlaufsbeobachtung bei 111 Patienten.

PURPOSE: The prevalence of cavernomas (cavernous hemangioma) is 0.1-0.7%. Cavernomas are often found as an incidental finding within the framework of magnetic resonance imaging (MRI) examinations in mainly young and healthy patients. In the literature, the reported risk of hemorrhage varies greatly and is sometimes higher than that of aneurysms, which is surprising given that cavernomas are part of the low blood pressure system. After the diagnosis the medical practitioner and the patient have to decide on the further therapy, either surgical removal or the strategy of watchful waiting (conservative treatment). The aim of our study was to determine the frequency of bleeding of cavernomas and the consequences and to determine the satisfaction of patients with treatment. All these aspects should make the therapeutic decision easier for medical practitioners. MATERIAL AND METHODS: The study included all patients who were treated in the military hospital in Ulm during the period 2002-2012 and with the diagnosis of one or more cavernomas of the central nervous system (CNS) detected by MRI. This resulted in a total number of 111 patients. We recorded the epidemiological data and analyzed all cavernomas with respect to the location, size, treatment, side effects, etc. Furthermore, all included patients were sent a comprehensive questionnaire about symptoms, course of the disease and the quality of life. The response rate was 38%. All the collected data were analyzed with respect to the various aspects. RESULTS: Depending on the definition of a bleeding event of a cavernoma and selection of the observational period, the probability of a hemorrhage risk ranged from 1.3% to 5.9% per patient year. This relatively high proportion is, however, put into perspective by the mostly mild consequences of a bleeding event. Many cavernomas, which were detected as an incidental finding showed signs of previous bleeding but the patients remained free of symptoms. Additionally, there was no patient in this collective who suffered serious consequences due to a bleeding event. Of the patients with temporal cavernomas 45% had symptomatic epilepsy. The results of the patient survey were heterogeneous. Some patients stated that in retrospect they would not choose surgical treatment again. CONCLUSION: As a result of our findings we think it is important to critically look at the indications for surgical removal of cavernomas and special attention must be paid to informed consent of the patient. The frequent appearance of temporal cavernomas and their propensity to epileptic seizures is an essential aspect, which certainly influences the therapeutic decision. Although cavernomas are a venous malformation in the low blood pressure system, the determined frequency of hemorrhage was 5.9%, which was higher than expected but which is confirmed by other studies. Reports on severe sequelae of cavernoma bleeding are also rare in the literature, which relativizes the resulting danger of the relatively high probability of hemorrhage.

Guidelines for the Treatment of Head Injury in Adults.

The workshop of scientific medical faculties (Arbeitsgemeinschaft wissenschaftlicher medizinischer Fakultäten [AWMF]) of Germany has asked societies of specific medical disciplines to jointly publish guidelines on the treatment of diseases and injuries. On behalf of the Deutsche Gesellschaft für Neurochirurgie, its commission on guidelines initiated an interdisciplinary approach to publish guidelines on the treatment of head injury in adults. These guidelines were published in German by the AWMF in late 2015. Because these guidelines have received widespread attention in Germany and became fundamental for research in head injuries, we have translated the German version into English to make it accessible to the international scientific community.

[PEEK cage fusion after anterior cervical corpectomy : Clinical and radiological results in patients with spondylotic myelopathy]. / PEEK-Cage-Fusion nach anteriorer zervikaler Korporektomie : Klinische und radiologische Ergebnisse bei spondylotischer Myelopathie.

BACKGROUND: Anterior cervical corpectomy and fusion (ACCF) has become a standard procedure for patients with spondylotic myelopathy due to multisegmental stenosis of the cervical canal. In addition to the fusion technique using autogenous bone grafts and titanium implants, synthetic polyetheretherketone (PEEK) cages have been used increasingly during the last years. However, limited evidence on the clinical and radiological results of PEEK cages for ACCF exists in the literature. The study presented here is the largest series to date reporting clinical and radiological outcome as well as complication rates after one to three-level ACCF using PEEK cages augmented by an anterior plate-screw osteosynthesis. MATERIALS AND METHODS: Retrospective study on 101 patients after stand-alone PEEK cage-ACCF with a minimum follow-up of 6 months. The number of hardware failures and implant-related surgical revisions were determined. The rate of subsidence and fusion and the course of lordotic alignment were analysed. The neck disability index (NDI) and the European myelopathy score (EMS) were assessed. RESULTS: Screw complications were detected in 8/101 cases and 3 cases of cage dislocation occurred, resulting in an overall implant related revision rate of 2.9 % (all revision cases showed cage dislocation). The rate of cage subsidence >3 mm was 12 % and solid fusion was achieved in 82 % of the patients. NDI, EMS and lordotic alignment improved significantly. CONCLUSIONS: PEEK cages are a safe and effective alternative to titanium cages or autogenous bone graft for ACCF. Further randomized evaluation of different fusion techniques in ACCF is still necessary.

[Spine surgery in a combat support hospital]. / Wirbelsäulenchirurgie unter den Bedingungen eines militärischen Auslandseinsatzes.

BACKGROUND AND AIM: From July 2007 to October 2014, neurosurgical services have been continuously available in a multinational Role 3 combat support hospital in Mazar-e-Sharif (MeS), Afghanistan. In this paper, we analyze a 7-year operative and outpatient spinal surgery caseload experience. MATERIALS AND METHODS: The overall annual and monthly caseloads were determined. Additionally, the surgical cases were differentiated relating to the strength of the indication, the location of the surgical site, and the origin of the patients. The outpatient caseload and spectrum of the years 2012 and 2013 were also analyzed. RESULTS: A total of 341 surgeries were performed and 188 of them were spinal surgeries (55.1 %). The vast majority of surgeries were performed for degenerative diseases (127/188; 67.6 %). The proportion of fractures and penetrating injuries (61/188; 32.4%) increased over the observation period. Eighty percent of the immediate and urgent surgeries (within 12 h; n = 70) were performed for these indications. 19.8 % of the surgeries were done as an emergency, whereas 17.3 % had delayed urgency, and 62.9 % were elective procedures. Of the 1026 outpatient consultations documented, 82 % of them were related to spinal diseases. CONCLUSIONS: The overall caseload in addition to the distribution of location, strength of indication, and patient origin for MeS are significantly lower than that reported by other International Security Assistance Force (ISAF) nations in eastern and southern Afghanistan. In addition, the rate of elective surgeries and those carried out in civilian Afghan patients is highest in MeS. In comparison with MeS, none of the other ISAF military hospitals shows such a strong concentration of degenerative spinal conditions in their surgical spectrum. Nevertheless, the changing pattern of spine-related diagnoses and surgical therapies in the current conflict represents a challenge for future educational and material planning in comparable missions.

Percutaneous vertebral augmentation with polyethylene mesh and allograft bone for traumatic thoracolumbar fractures.

Purpose. In cases of traumatic thoracolumbar fractures, percutaneous vertebral augmentation can be used in addition to posterior stabilisation. The use of an augmentation technique with a bone-filled polyethylene mesh as a stand-alone treatment for traumatic vertebral fractures has not yet been investigated. Methods. In this retrospective study, 17 patients with acute type A3.1 fractures of the thoracic or lumbar spine underwent stand-alone augmentation with mesh and allograft bone and were followed up for one year using pain scales and sagittal endplate angles. Results. From before surgery to 12 months after surgery, pain and physical function improved significantly, as indicated by an improvement in the median VAS score and in the median pain and work scale scores. From before to immediately after surgery, all patients showed a significant improvement in mean mono- and bisegmental kyphoses. During the one-year period, there was a significant loss of correction. Conclusions. Based on this data a stand-alone approach with vertebral augmentation with polyethylene mesh and allograft bone is not a suitable therapy option for incomplete burst fractures for a young patient collective.

Early postoperative results after removal of cranially migrated lumbar disc prolapse: retrospective comparison of three different surgical strategies.

Background. To compare the early postoperative results of three surgical approaches to lumbar disc herniations that migrated cranially. Minimally invasive techniques such as the translaminar and endoscopic transforaminal approaches are utilized in patients with lumbar disc herniations to gain access to cranially located disc material and to avoid the potentially destabilizing resection of ligament and bone tissue, which is associated with an extended interlaminar approach. Methods. This retrospective study compares the postoperative pain and functional capacity levels of 69 patients who underwent an interlaminar (Group A, n = 27), a translaminar (Group B, n = 22), or an endoscopic transforaminal procedure (Group C, n = 20). Results. Median VAS scores for leg pain decreased significantly from before to after surgery in all groups. Surgical revisions were required in thirteen cases (five in Group A, one in Group B, and seven in Group C; P = 0.031). After six weeks, there were significant differences in back pain and functional outcome scores and in the results for the MacNab criteria but not in leg pain scores. Conclusions. The interlaminar and translaminar techniques were the safest and fastest ways of gaining access to cranially migrated disc material and the most effective approaches over a period of six weeks.

[Selective dorsal decompression of degenerative cervical canal stenosis]. / Selektive dorsale Dekompression der degenerativen Zervikalstenose.

BACKGROUND: Hypertrophy of the dorsal ligaments is one reason for central stenosis of the cervical spinal canal. Selective decompression techniques without stabilization and fusion could be a sufficient alternative surgical treatment option. MATERIAL AND METHODS: This article presents the results of an observational study on 17 patients after treatment with selective decompression and undercutting of the cervical laminae and medial joint portion. The Japanese Orthopedic Association (JOA) score, the neck pain disability index (NPDI) and arm and neck pain on a visual analogue scale (VAS) were compared preoperatively and postoperatively (mean follow-up period was 14 months, minimum 12 months). The reduction of the stenosis and degree of adjacent level disease were measured using presurgical and postsurgical magnetic resonance imaging (MRI). The segmental and regional lordosis and range of motion were determined using the Cobb method on plain standing lateral radiographs. RESULTS: There were no complications and no revision surgery was necessary. All clinical parameters improved significantly. The stenosis was significantly decompressed and no progression of myelopathy was observed on MRI. The sagittal parameters and degree of adjacent level degeneration remained unchanged. CONCLUSION: The clinical and radiological results of this non-fusion technique are convincing. Selective decompression is therefore an alternative to laminectomy and fusion as well as laminoplasty.

[Experiences with cement leakage after balloon kyphoplasty]. / Erfahrungen mit intravasalen Zementaustritten nach Ballonkyphoplastie.

BACKGROUND: Kyphoplasty is associated with a low incidence of cement leakage and this usually tends to be clinically asymptomatic. However, there is a potential for life-threatening complications from extraspinal leakage resulting in vascular, cardiac and pulmonary embolisms. A total of eight cases of open surgical thrombectomy for cardiopulmonary cement leakage have been published in the current literature to date. Besides the description of a consecutive series with special reference to extraspinal cement leakage this article presents the results after successful endovascular removal of intravenous cement fragments following kyphoplasty in two patients. MATERIALS AND METHODS: In 46 cases following balloon kyphoplasty the number and amount of extraspinal venous cement leakage was retrospectively determined using computed tomography (CT). The number of cement embolisms into the pulmonary venous system was differently revealed for patients showing no extravertebral leakage or leakage only into the external vertebral venous plexus compared to leakage into the major venous vessels, azygos and hemiazygos vein or inferior vena cava. RESULTS: In 8 out of 046 cases (17.4 %) leakage into the external vertebral venous plexus was detected. In 5 out of 8 cases without involvement of the azygos/hemiazygos vein or inferior vena cava no pulmonary cement embolism was detected. In 3 out of 8 cases the inferior vena cava or azygos/hemiazygos vein was reached and additionally asymptomatic peripheral pulmonary cement embolism was induced in these cases. In two cases harboring residual intravasal cement fragments treatment was successful using endovascular extraction techniques. CONCLUSIONS: A computed tomography scan after kyphoplasty is recommended for all cases. If there is involvement of the inferior vena cava or the azygos/hemiazygos vein an additional CT scan of the chest should follow, even in asymptomatic cases. Residual intravasal cement fragments are safely extractable using endovascular techniques.

Translaminar approach to cranio-laterally herniated lumbar disc prolapse.

BACKGROUND: For cranio-laterally extruded disc fragments, a far enlargement of the standard interlaminar fenestration is necessary. This strategy harbours a potential risk for relevant destruction of the facet joints and postsurgical instability could be the consequence. For preserving the facet joint, a limited approach through the hemilamina is possible. METHOD: After the standard paramedian soft tissue approach and retraction of the paravertebral muscles laterally, the hemilamina is exposed and fenestrated, preserving the bony borders of the lamina. The disc herniation can be extracted via this lamina fenestration. CONCLUSION: This surgical strategy is safe and effective in approaching cranially herniated disc fragments.

[Diagnosis and treatment of injuries to the frontal skull base]. / Diagnostik und Therapie von Verletzungen der Frontobasis.

The role of ENT surgery in the management of anterior skull base defects has become increasingly important in recent years. Transnasal endoscopic surgical techniques and intraoperative navigation enable a minimally invasive approach in a large proportion of patients, thus helping to avoid morbidity typically associated with neurosurgical subfrontal approaches. Whereas traffic accidents and sport injuries are the main causes of anterior skull base trauma in the civilian setting, penetrating injuries caused by gunshots and improvised explosive devices (IEDs) play an increasing role in the military arena and terroristic attacks. Minor injuries to the anterior skull base are usually managed by ENT surgeons. Major injuries, involving the midface or neurocranium, require an interdisciplinary approach including maxillofacial surgeons and neurosurgeons. A centre for head and neck medicine and surgery is an ideal setting for such interdisciplinary teams to provide appropriate care for patients with complex skull base trauma in cooperation with ophthalmologists and interventional neuoradiologists. The present article describes concepts for the treatment of anterior skull base trauma established at the head, neck and skull base center at the Ulm military hospital in Germany.

[Postoperative course after acute traumatic subdural hematoma in the elderly. Does the extent of craniotomy influence outcome?]. / Postoperativer Verlauf nach akutem Subduralhämatom im höheren Lebensalter. Hat das Ausmaß der Kraniotomie einen Einfluss auf das Ergebnis?

AIM: The goal of the study was to analyze the short-term outcome after surgical treatment of acute subdural hematomas in two treatment groups in a patient population >65 years. Whether there are disadvantages from invasive treatment or whether advantages can be achieved with the less invasive treatment has not been previously examined in a prospective study. METHODS: A prospective, nonrandomized study of 50 patients >65 years with acute traumatic subdural hematoma was performed, comparing the short-term outcome after two different primary surgical procedures: limited craniotomy (group A, n=25) and large decompressive craniectomy (group B, n=25). RESULTS: There were no differences of hematoma volume, degree of midline structure shift, and time from trauma to operation between the two groups. Initial Glasgow coma scale and short-term outcome after 4 weeks measured by the Glasgow outcome score in both groups showed no significant differences. CONCLUSION: No significant differences between short-term outcome after limited craniotomy versus large decompressive craniectomy were found for patients >65 years, and the results indicate that decompressive craniectomy can be accepted as a surgical treatment option for acute traumatic subdural hematoma even in elderly patients.

[Percutaneous CT-guided destruction versus microsurgical resection of lumbar juxtafacet cysts]. / Perkutane CT-gesteuerte Destruktion vs. mikrochirurgische Resektion lumbaler Juxtafacettzysten.

BACKGROUND: Microsurgical resection is the standard treatment of lumbar juxtafacet cysts. Percutaneous computed tomography (CT) guided destruction of the cyst could be an alternative modality for inoperable patients. Comparative prospective studies for both treatment strategies do not exist. MATERIALS AND METHODS: This study involved a non-randomized, prospective trial on 45 patients suffering from sciatica or claudication caused by lumbar juxtafacet cysts. Of the patients 25 were operated on microsurgically and 20 patients were primarily treated using percutaneous CT-guided cyst destruction. RESULTS: The treatment in both groups was performed without complications in all patients. All patients treated microsurgically were pain-free (mean postoperative interval 27 months) but only 8 out of 20 patients treated percutaneously recovered completely (mean post-treatment interval 24 months). The remaining 12 out of 20 patients showed no relevant improvement and were operated on microsurgically. CONCLUSION: Minimally invasive cyst destruction is not a viable alternative to microsurgical resection considering the long-term outcome, neither in this study nor in the reviewed literature.

Surgery without assistance in newborns and infants with hydrocephalus and neural tube defects.

Standard neurosurgical procedures for hydrocephalus and open neural tube defects in newborns and infants under 6 months of age were performed by a single neurosurgeon on his own without the help of an assistant or scrub nurse. The objective of this study was to assess the outcome of these procedures in terms of operating time, the presence of bacterial infection, and wound healing. Between 2001 and 2004, a total of 126 procedures were performed on 82 patients under 6 months of age. We observed 1 bacterial and 2 fungal infections. Two infections had already been detected at the beginning of the surgical procedure in cerebrospinal fluid (CSF) specimens obtained from children with Candida ventriculitis. The other infection occurred after leakage of CSF from a myelomeningocele 10 days after initial surgery. Our study suggests that excellent results can be achieved in standard neurosurgical procedures without assistance even in high-risk newborns and infants if resource or other constraints require such an unconventional approach.

[Chronic subdural hematoma in patients under 35 years of age]. / Chronisches subdurales Hämatom bei Patienten unter 35 Jahren.

OBJECTIVE: Although chronic subdural haematoma (CSDH) is considered a condition of the elderly, it may also occur in younger patients. The objective of this study was to identify the cause of CSDH in younger patients. METHOD: In a group of 100 consecutive patients with CSDH diagnosed in our hospital between 1 January 2000 and 31 August 2003, we found nine patients to be younger than 35. These nine were assessed to identify their cause of CSDH. RESULTS: We found a predisposing cause in five of nine patients, three having a disorder of CSF balance, and two having a clotting disorder. Trauma was reported in only two of these five patients. Among the four patients without a predisposing factor a trauma was reported in three of them. In only one patient the cause of CSDH remained unknown. All patients made a complete recovery. CONCLUSION: Chronic subdural haematoma did also occur in younger patients. Trauma, CSF imbalance, and deranged clotting increase the risk of CSDH, however this disorder can also occur in the absence of identifiable predisposing factors or trauma.

[Spinal epidural empyema. Limited surgical treatment combined with continuous irrigation and drainage]. / Spinales epidurales Empyem. Limitierte operative Behandlung kombiniert mit kontinuierlicher Spüldrainage.

Epidural empyema of the spinal column is a rare, but in some cases devastating, disease. Surgery can be excessive or very limited. We want to report our results of combined therapy of limited surgical treatment and continuous irrigation with antibiotic solution and drainage. In the last 5 years we have operated on 12 patients (7 female, 5 male, median age: 61.5 years, range: 22-89 years) with spinal epidural empyema. All surviving patients were evaluated after 3 months including MRI. Six infections were caused by injections, two by spontaneous discitis, two by chronic systemic infections, and in two patients the cause remained unknown. In every case we implanted two catheters, one for irrigation with antibiotic solution and one for drainage. On average the catheters were used for 3 days. For evacuation in seven patients interlaminar fenestration in one, two, or three levels was enough. Only in one patient was a laminectomy performed. Five patients recovered totally, three partially, one did not recover at all, and three died. The autopsy of two dead patients showed complete healing of the operated area; they died because of lethal infections in other parts of their body. In only one case did a reoperation have to be done. The cause was an additional subdural empyema. In spite of the limited surgical procedure without relevant operative morbidity the reported method is an effective and safe therapy.

[Intraoperative three-dimensional imaging to monitor selective decompression in lumbar spinal stenosis]. / Intraoperative 3D-Bildgebung zur Kontrolle der selektiven Dekompression bei lumbaler Wirbelkanalstenose.

BACKGROUND: We are looking for a possibility to examine the amount of decompression in operations for spinal stenosis with an Iso-C(3D) fluoroscope (Siemens). METHODS: In ten patients operated on because of spinal stenosis from one side with undercutting, we performed a scan with the Iso-C(3D) fluoroscope during the operation. In five patients we additionally performed intraoperative myelography. RESULTS: In all cases we were able to make useful scans. Two times we changed our surgical procedure because of the scans. There were no complications because of the investigation with the Iso-C(3D) fluoroscope and none related to the myelography, but the myelography was dispensable. CONCLUSIONS: It is possible and useful to investigate the decompression in spinal stenosis intraoperatively with less effort.

Lumbosacral extradural arachnoid cysts: diagnostic and indication for surgery.

No critical discussion of the indication for the surgical treatment of lumbosacral extradural arachnoid cysts is found in the literature. Therefore, we want to compare the results in patients with operative and conservative treatment to define standards for a good surgical result. Over a period of 9 years, we operated on eight patients with a lumbosacral extradural arachnoid cyst and treated eight others conservatively. Only three of the operated patients experienced a postoperative relief of pain, but none was symptom free. The only one with continuing success had a preoperative history of 1 year only. MRI scans without contrast agent were misinterpreted in one included and one excluded case. The results of conservative treatment were nearly the same as those of operative treatment. MRI is the best diagnostic tool, but a variety of sequences must be used. Patients with a short pain history and a clear neurological deficit profited most from surgery. Patients with slight and not clearly related uncharacteristic symptoms should be excluded from surgery.

[Significance of distal motor latency after carpal tunnel operation]. / Zur Bedeutung der distalen motorischen Latenz nach Karpaltunneloperationen.

Motor distal latency (MDL) is one of the most important parameters in the electrodiagnosis of carpal tunnel syndrome (CTS). In a retrospective study of 1816 open surgical decompressions for CTS, a total of 612 postoperative motor nerve conduction measurements on 485 hands could be evaluated. In patients with good or satisfactory results after carpal tunnel release, an average improvement of MDL of 1.0 ms after 9-13 days, and of 2.2 ms after 1 year and longer was found. The individual motor nerve conduction improvement was in close correlation with the extent of preoperative prolongation of the MDL. Whereas relief of symptoms can be noted almost immediately, prolonged latencies often do not return to normal, even when the study is done a year later. Of the 10 patients with persisting symptoms, four had a new postoperative impairment of MDL, and also four had a marked improvement, whereas it remained unchanged in two. Patients with severe recurrent CTS presented in 11 out of 31 cases with an improved MDL from 0.3 ms to 3.0 ms in comparison to the initial preoperative evaluation; in 6 hands MDL was unchanged, further prolongation up to 2.0 ms was seen in 6 cases and marked worsening with new loss of motor response had to be noted in 8 hands at repeat electrodiagnosis. In 33 cases of postoperative reflex sympathetic dystrophy, an improvement of MDL from 0.3 ms to 3.3 ms (mean 1.7 ms) was observed in 22 hands and dissolution of a preexisting motor conduction block in three others, whereas two remained unchanged (without motor response) and an electrophysiological impairment was found only in six hands. Three of them presented with a further prolongation of MDL from 0.3 to 1.0 ms and a new loss of response was noted in the remaining three. In conclusion, postoperative motor nerve conduction studies may assess a favorable course following carpal tunnel release. However, they are often not helpful when surgical results are unsatisfactory, and indication for repeat surgical decompression should be based merely on clinical symptoms.