Comparative Anatomic Analysis of Neuronavigated Transmastoid-Infralabyrinthine Approaches for Jugular Fossa Pathologies: Short Anterior Rerouting Versus Nonrerouting and Tailored Nonrerouting Techniques.

BACKGROUND AND OBJECTIVES: Access to the jugular fossa pathologies (JFPs) via the transmastoid infralabyrinthine approach (TI-A) using the nonrerouting technique (removing the bone anterior and posterior to the facial nerve while leaving the nerve protected within the fallopian canal) or with the short-rerouting technique (rerouting the mastoid segment of the facial nerve anteriorly) has been described in previous studies. The objective of this study is to compare the access to Fisch class C lesions (JFPs extending or destroying the infralabyrinthine and apical compartment of the temporal bone with or without involving the carotid canal) between the nonrerouting and the short-rerouting techniques. Also, some tailored steps to the nonrerouting technique (NR-T) were outlined to enhance access to the jugular fossa (JF) as an alternative to the short-rerouting technique. METHODS: Neuronavigated TI-A was performed using the nonrerouting, tailored nonrerouting, and short-rerouting techniques on both sides of 10 human head specimens. Exposed area, horizontal distance, surgical freedom, and horizontal angle were calculated using vector coordinates for nonrerouting and short-rerouting techniques. RESULTS: The short-rerouting technique had significantly higher values than the NR-T ( P < .01) for the exposed area (169.1 ± SD 11.5 mm 2 vs 151.0 ± SD 12.4 mm 2 ), horizontal distance (15.9 ± SD 0.6 mm vs 10.6 ± SD 0.5 mm 2 ), surgical freedom (19 650.2 ± SD 722.5 mm 2 vs 17 233.8 ± SD 631.7 mm 2 ), and horizontal angle (75.2 ± SD 5.1° vs 61.7 ± SD 4.6°). However, adding some tailored steps to the NR-T permitted comparable access to the JF. CONCLUSION: Neuronavigated TI-A with the short-rerouting technique permits wider access to the JF compared with the NR-T. However, the tailored NR-T provides comparable access to the JF and may be a better option for class C1 and selected class C2 and C3 JFPs.

Assessing the feasibility of the transmastoid infralabyrinthine approach without decompression of the jugular bulb to the extradural part of the petrous apex and petroclival junction prior to surgery.

BACKGROUND AND OBJECTIVE: This study aims to define specific measurements on cranial high-resolution computed tomography (HRCT) images prior to surgery to prove the feasibility of the navigated transmastoid infralabyrinthine approach (TI-A) without rerouting of the facial nerve (FN) and decompression of the jugular bulb (JB) in accessing the extradural-intrapetrous part of petrous bone lesions located at the petrous apex and petroclival junction. MATERIALS AND METHODS: Vertical and horizontal distances of the infralabyrinthine space were measured on cranial HRCT images prior to dissection. Subsequently, the area of access was measured on dissected human cadaveric specimens. Infralabyrinthine access to the extradural part of the petrous apex and petroclival junction was evaluated on dissected specimens by two independent raters. Finally, the vertical and horizontal distances were correlated with the area of access. RESULTS: Fourteen human cadaveric specimens were dissected bilaterally. In 54% of cases, the two independent raters determined appropriate access to the petrous apex and petroclival junction. A highly significant positive correlation (r = 0.99) was observed between the areas of access and the vertical distances. Vertical distances above 5.2 mm were considered to permit suitable infralabyrinthine access to the extradural area of the petrous apex and petroclival junction. CONCLUSIONS: Prior to surgery, vertical infralabyrinthine distances on HRCT images above 5.2 mm provide suitable infralabyrinthine access to lesions located extradurally at the petrous apex and petroclival junction via the TI-A without rerouting of the FN and without decompression of the JB.

Patient Satisfaction and Radiologic Assessability After Treatment of Complex Skull Defects With a Custom-Made Cranioplasty From a Thin Titanium Sheet.

OBJECTIVE: The cosmetically good coverage of skull defects is a challenge in neurosurgical clinics. In addition, the skull treated with implants and the underlying structures must remain radiologically assessable. In this examination, the postoperative courses of patients after implantation of CranioTop is described. Digital x-ray, computed tomography, and magnetic resonance images after implantation of CranioTop were evaluated with regard to their assessability. MATERIALS AND METHODS: Between 2018 and 2020, 23 titanium cranioplasties (CranioTop) were implanted to 21 patients. The intraoperative handling, the accuracy of fit, the healing process, the cosmetic result and the physical condition of the patients were examined. In addition, digital x-rays, magnetic resonance imaging, and computed tomography scans of the cranium supplied with CranioTop were examined. RESULTS: The evaluation showed good to very good results regarding patients' satisfaction. There were no severe complications; thirteen patients found the cosmetic result very good; 8 patients assessed the cosmetic result as good. Because of the low thickness and density of the CranioTop plastic there was only low formation of radial stripe artifacts (streaking) and susceptibility artifacts. The assessment of digital x-ray, computed tomography, and magnetic resonance imaging images is possible after implantation of CranioTop. CONCLUSION: The patients treated with CranioTop showed a high level of satisfaction with regard to the cosmetic result and their physical condition. Furthermore, the cranium supplied with CranioTop remains well assessable in radiologic imaging with only slight limitations in magnetic resonance imaging.

Rescuing Infected Deep Brain Stimulation Therapies in Severely Affected Patients.

(1) Background: Infections in deep brain stimulation (DBS) hardware, while an undesired complication of DBS surgeries, can be effectively addressed. Minor infections are typically treated with wound revision and IV antibiotics. However, when visible hardware infection occurs, most centers opt for complete removal, leaving the patient in a preoperative state and necessitating post-removal care. To avoid the need for such care, a novel technique was developed. (2) Methods: The electrodes are placed at the exact same spot and then led to the contralateral side. new extensions and a new generator contralateral to the infection as well. Subsequently, the infected system is removed. This case series includes six patients. (3) Results: The average duration of DBS system implantation before the second surgery was 272 days. Only one system had to be removed after 18 months due to reoccurring infection; the others remained unaffected. Laboratory alterations and pathogens were identified in only half of the patients. (4) Conclusions: The described surgical technique proves to be safe, well tolerated, and serves as a viable alternative to complete system removal. Importantly, it effectively prevents the need of post-removal care for patients.

Surgical treatment of spondylodiscitis in critically ill septic patients.

PURPOSE: Surgical procedures in critically ill patients with spondylodiscitis are challenging and there are several controversies. Here, we present our experience with offering surgical intervention early in critically ill septic patients with spondylodiscitis. METHOD: After we introduced a new treatment paradigm offering early but limited surgery, eight patients with spondylodiscitis complicated by severe sepsis and multiple organ failure underwent urgent surgical treatment over a 10-year period. Outcome was assessed according to the Barthel index at 12-month follow-up and at the last available follow-up (mean 89 months). RESULTS: There were 7 men and 1 woman, with a mean age of 62 years. The preoperative ASA score was 5 in 2 patients, and 4 in 6 patients. Six of them presented with high-grade paresis, and in all of them, spondylodiscitis with intraspinal and/or paravertebral abscesses was evident in MR imaging studies. All patients underwent early surgery (within 24 h after admission). The median time in intensive care was 21 days. Out of the eight patients, seven survived. One year after surgery, five patients had a good outcome (Barthel index: 100 (1); 80 (3); and 70 (1)). At the last follow-up (mean 89 months), 4 patients had a good functional outcome (Barthel index between 60 and 80). CONCLUSION: Early surgical treatment in critically ill patients with spondylodiscitis and sepsis may result in rapid control of infection and can provide favorable long-term outcome. A general strategy of performing only limited surgery is a valid option in such patients who have a relatively high risk for surgery.

Surgical treatment of selected tumors via the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach without rerouting of the facial nerve.

The feasibility of a novel skull base approach - the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach (NaMIPSI-A) without rerouting of the fallopian canal for selected jugular foramen tumors (JFTs) - has been demonstrated in a neuroanatomical laboratory study. Here, we present our clinical experience with the NaMIPSI-A for selected JFTs, with a particular focus on its efficacy and safety. All patients with JFTs who were treated via the NaMIPSI-A were included in this study. The JFTs were classified according to a modified Fisch classification. The neurological and neuroradiological outcome, the extent of tumor resection, and the approach-related morbidity were examined. Five patients (two women, three men; mean age 57 years, range 48-65) were available. According to the modified Fisch classification, two JFTs were graded as C1, one as De1, and two as De2. Gross total resection (GTR) was achieved in three patients and near-total resection (NTR) in two. Postsurgically, no new neurological deficits and no approach-related morbidity and mortality occurred. One case with a postoperative cerebrospinal fluid leak was managed successfully with lumbar drainage. During the follow-up period (mean 67.6 months, range 12-119 months), tumor recurrence was noted in the NTR group but not in the GTR group. The NaMIPSI-A to the jugular foramen without rerouting of the fallopian canal is highly valuable for selected tumors of the jugular foramen. It is less invasive than other skull base approaches, and it allows safe and complete tumor removal in appropriate patients.

Transpedicular Lumbar Fusion in Patients without Improvement of Low Back Pain Following Implantation of Disc Prostheses.

AIM: To evaluate the option of lumbar transpedicular fixation at the index level in patients who did not achieve adequate pain relief after lumbar total disc replacement (TDR) without evidence of device failure. MATERIAL AND METHODS: Four patients (mean age, 47 years) presented with persistent low back pain following lumbar TDR for 12-24 months (mean, 16.3). No device failures were observed. All patients underwent transpedicular fixation at the index level. Clinical outcome was assessed via the Oswestry disability index, a visual analog scale, and recording of the consumption of analgesics. RESULTS: No postoperative complications were observed. The average follow-up after lumbar transpedicular fixation was 53.5 months (range, 43-80). Two patients considered the outcome as excellent, one as good, and one as poor. The mean visual analog scale pain score decreased from 7.8 (range, 7-8) to 4.3 (range, 2-8). The mean Oswestry disability index decreased from 43.5 (range, 39?47) to 27.5 (range, 14-47). At the last follow-up, one patient was without analgesic medication and substitution of opiates with non-opioid analgesics was possible in two patients. CONCLUSION: In patients with persistent low back pain after TDR without device failure or adjacent segment pathologies, lumbar transpedicular fixation without removal of the disc prosthesis may be a useful therapeutic option.

Emergency Lumbar Disk Operation: How Safe Is it?

Background and Study Aims It was suggested that emergency operations could represent a risk factor for complications. The purpose of this study was to evaluate whether complication rates are higher in emergency lumbar disk operations compared with elective lumbar disk surgery. Materials and Methods Patient data sets from 575 microscopic lumbar disk surgeries performed within a 5-year period were evaluated in a retrospective study design. There were 498 patients after excluding those who had surgery for recurrent disk herniation. Overall, 460 patients (92.4%) underwent elective surgery (nonemergency group), and 38 patients (7.6%) were operated on in an emergency setting (emergency group). The incidence of dural tears, the frequency of intra- and perioperative complications, the rate of recurrent disk herniation, and the length of hospital stay were evaluated. Results No statistically significant differences between the two groups were found with regard to the incidence of dural tears (7.9% in the emergency group, 4.3% in the nonemergency group; p = 0.32), the rate of complications (2.6% in the emergency group, 2.8% in the nonemergency group; p = 0.95), the rate of recurrent disk herniation (8.9% versus 10.5%; p = 0.74), and the length of hospital stay (p = 0.22). Conclusions Emergency lumbar disk surgery has a similar safety profile as elective surgery. Patients who present with acute or progressive neurologic deficits and need emergency surgery are not exposed to a higher risk of surgery.

Current practice of external ventricular drainage: a survey among neurosurgical departments in Germany.

BACKGROUND: There are various recommendations, but no generally accepted guidelines, to reduce the risk of external ventricular drainage (EVD)-associated infections. The primary objective of the present study was to evaluate the current practice of EVD in a European country and to set the results in perspective to published data. METHOD: A standardised questionnaire prepared by the Commission of Technical Standards and Norms of the German Society of Neurosurgery was sent to 127 neurosurgical units in Germany. RESULTS: Data were analysed from 99 out of 127 neurosurgical units which had been contacted. Overall, more than 10,000 EVD procedures appear to be performed in Germany annually. There is disagreement about the location where the EVD is inserted, and most EVDs are still inserted in the operation theatre. Most units apply subcutaneous tunnelling. Impregnated EVD catheters are used regularly in only about 20 % of units. Single-shot antibiotic prophylaxis is given in more than half of the units, while continued antibiotic prophylaxis is installed in only 15/99 units at a regular basis. There are discrepancies in the management of prolonged EVD use with regard to replacement policies. Regular cerebrospinal fluid (CSF) sampling is still performed widely. There were no statistical differences in policies with regard to academic versus non-academic units. CONCLUSIONS: This survey clearly shows that some newer recommendations drawn from published studies penetrate much slower into clinical routine, such as the use of impregnated catheters, for example. It remains unclear how different policies actually impact quality and outcome in daily routine.

Electromagnetic navigation-guided surgery in the semi-sitting position for posterior fossa tumours: a safety and feasibility study.

BACKGROUND: Electromagnetic (EM)-guided neuronavigation is an innovative technique and a viable alternative to opto-electric navigation. We have performed a safety and feasibility study using EM-guided neuronavigation for posterior fossa surgery in the semi-sitting position in a selected subset of patients. METHODS: Out of 284 patients with posterior fossa tumours operated upon over a period of 40 months, a subset of 15 patients was thought to possibly benefit from EM navigational guidance and was included in this study. There were six children and nine adults (aged between 8 and 84 years; mean age, 34.6 years) with different neoplasms in the brainstem or close to the midline. All patients had contrast-enhanced three-dimensional (3D) magnetic resonance imaging (MRI) of the head preoperatively. EM-guided navigation was used to identify and preserve the venous sinuses during craniotomy and to determine the trajectory to the lesion using various approaches. Neuronavigation accuracy was repeatedly checked for deviations measured in millimetres on screen shots during surgery before and after dural opening in the coronal (z = vertical), axial (x = mediolateral) and sagittal (y = anteroposterior) plane. RESULTS: Referencing of the patient in the supine position was fast and easy. There was no loss of navigation accuracy after repositioning of the patient in the semi-sitting position (mean, 2.5 mm ± 0.92 mm). Identification of the pathological structure using EM navigation was achieved in all instances. Optimal angulation of the neck was selected individually to permit a comfortable position for the surgeon with full access to the lesion avoiding over-flexion. Deviation of accuracy at the surface of the target lesion ranged between 2.5 and 5.8 mm (mean, 3.9 mm ± 1.1 mm). CONCLUSIONS: EM-guided neuronavigation in the semi-sitting position was safe and technically feasible. It enabled fast and accurate referencing without loss of navigation accuracy despite repositioning of the patient. In contrast to conventional opto-electric neuronavigation there were no line of sight problems.

Navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach to the jugular foramen without rerouting of the facial nerve.

BACKGROUND: Jugular foramen tumors are rare and challenging lesions for skull base surgeons because of their difficult operative accessibility. Various surgical approaches to the jugular foramen have been described to overcome the morbidity of standard petrosectomy. OBJECTIVE: To describe the surgical anatomy of a novel route to the jugular foramen without opening the fallopian canal, the navigated tailored presigmoidal suprabulbar infralabyrinthine approach. METHODS: Ten cadaver heads were dissected under navigational guidance on both sides to examine the advantages and limitations of the presigmoidal suprabulbar infralabyrinthine approach without opening the fallopian canal. Mastoidectomy was performed by using a high-speed drill. Under navigation guidance, the sigmoid sinus, jugular bulb, posterior semicircular canal, and fallopian canal were located and preserved. The jugular foramen with the extradural part of the IXth, Xth, and XIth nerve were identified. RESULTS: Measurements of the surgical corridor and exposed petrous bone area on high-resolution computed tomography showed that the navigated presigmoidal suprabulbar infralabyrinthine approach without opening the fallopian canal is a suitable route for extradural jugular foramen lesions with limited extension (approach height 5.59 ± 0.16 mm; approach width 7.68 ± 0.18 mm; approach surface 33.73 ± 1.37 mm; approach depth 32.92 ± 0.21 mm; vertical angle α of the surgical approach 41.3° ± 0.9°; horizontal angle ß of the surgical approach 40.5° ± 0.6°). CONCLUSION: The navigation-guided presigmoidal suprabulbar infralabyrinthine approach is a minimally invasive approach for selected lesions of the jugular foramen with preservation of the fallopian canal, labyrinthine block, and sigmoid sinus. This approach is suited for C1, De1, De2, Di1, and Di2 tumors according to the Fisch classification.