Digital Patient-Reported Outcome Measures Assessing Health-Related Quality of Life in Skull Base Diseases-Analysis of Feasibility and Pitfalls Two Years after Implementation.

Health-related quality of life (HRQoL) assessment is becoming increasingly important in neurosurgery following the trend toward patient-centered care, especially in the context of skull base diseases. The current study evaluates the systematic assessment of HRQoL using digital patient-reported outcome measures (PROMs) in a tertiary care center specialized in skull base diseases. The methodology and feasibility to conduct digital PROMs using both generic and disease-specific questionnaires were investigated. Infrastructural and patient-specific factors affecting participation and response rates were analyzed. Since August 2020, 158 digital PROMs were implemented in skull base patients presenting for specialized outpatient consultations. Reduced personnel capacity led to significantly fewer PROMs being conducted during the second versus (vs.) the first year after introduction (mean: 0.77 vs. 2.47 per consultation day, p = 0.0002). The mean age of patients not completing vs. those completing long-term assessments was significantly higher (59.90 vs. 54.11 years, p = 0.0136). Follow-up response rates tended to be increased with recent surgery rather than with the wait-and-scan strategy. Our strategy of conducting digital PROMs appears suitable for assessing HRQoL in skull base diseases. The availability of medical personnel for implementation and supervision was essential. Response rates during follow-up tended to be higher both with younger age and after recent surgery.

[Angioedema in the emergency department]. / Das Angioödem in der Notaufnahme.

Acute angioedema is mostly found in the head and neck region. Therefore, it can be life threatening by potentially endangering air way patency. Pathophysiologically angioedemas can be divided into mast cell-mediated or bradykinin-mediated forms. Differentiation is essential due to the different therapeutic strategies. In cases of doubt, initial therapy with adrenalin, antihistamines, and glucocorticoids should be initiated. This initial emergency treatment is comparable to the treatment of allergic reactions. For diagnosed or suspected hereditary angioedema, specific treatments are available. For drug-associated forms, immediate and life-long cessation of the medication is crucial. In the emergency situation, diagnosis can only be based on medical history and clinical symptoms. Recognition of impending airway obstruction and securing the airway is of highest priority; final diagnosis must be confirmed later.

Piezosurgery-A Safe Technique to Perform Lateral Suboccipital Craniotomy?

BACKGROUND: Piezosurgery (PS) is a relatively new technique based on microvibrations generated by the piezoelectric effect. It selectively cuts bone tissue and preserves the surrounding soft tissue. OBJECTIVE: To evaluate the use of PS for performing lateral suboccipital craniotomy. METHODS: PS was used to perform a lateral suboccipital craniotomy in 22 patients who underwent surgery for different cerebellopontine angle (CPA) pathologies in the neurosurgical department. The applicability of PS for lateral suboccipital craniotomy was evaluated with respect to safety, preciseness of bone cutting, and in particular the preservation of the adjacent dura and sigmoid and transverse sinuses. RESULTS: Lateral suboccipital craniotomy in 22 patients who underwent surgery for different CPA pathologies (13 vestibular schwannoma, 5 petrous bone meningioma, 1 petroclival meningioma, 2 epidermoid cysts, and 1 petrous bone cholesterol granuloma) was performed with PS without any complications. A burr hole was set before piezosurgical craniotomy in 6 patients, with no prior burr hole in 16 patients. Incidental durotomy during piezosurgical craniotomy occurred in 6 patients, and small lacerations of the sigmoid sinus caused by the piezosurgical device were observed in 3 patients. CONCLUSION: Although PS is a safe and selective bone cutting technique that preserves the surrounding soft tissue, it can still lead to unintended dural tears during lateral suboccipital craniotomy. This must be kept in mind when using PS for craniotomies and relying on the selective bone cutting properties of PS.

Piezosurgery-, neuroendoscopy-, and neuronavigation-assisted intracranial approach for removal of a recurrent petrous apex cholesteatoma: technical note.

Current approaches for resection of petrous bone cholesteatomas (PBCs), such as canal wall up (closed) and canal wall down (open) mastoidectomies, in the pediatric population present recurrence rates ranging between 17% and 70% with a high rate of postoperative complications involving hearing loss and facial nerve weakness. This technical note illustrates an alternative intracranial approach that was used in combination with the techniques of piezoelectric surgery, neuroendoscopy, and neuronavigation for safe and effective removal in a difficult pediatric case of recurrent PBC. The third recurrence of a PBC in a 14-year-old girl was diagnosed by CT and MRI. A retrosigmoid approach gave access to the petrous apex, allowing for the safe and complete removal of the lesion and decompression of the facial nerve and internal carotid artery. The intraoperative implementation of piezoelectric surgery, neuronavigation, neuroendoscopy, and neuromonitoring ensured better intraoperative visualization, safer bone removal, and preservation of nerve function, facilitating a macroscopically total resection of the pathology without additional neurological damage of the adjacent tissues. Cholesteatoma extension could be clearly verified by intraoperative neuronavigation. Neuroendoscopy and piezoelectric surgery provided good support in the safe bone removal in close vicinity to neurovascular structures and in full vision inside the cholesteatoma cavity beyond the line of sight of the microscope. Hearing and facial nerve function could be preserved. The presented intracranial retrosigmoid approach combined with multiple intraoperative assisting techniques proved to be effective for the safe and complete removal of recurrent PBC, providing excellent intraoperative visualization and the possibility of preserving cranial nerve function.

Navigation accuracy after automatic- and hybrid-surface registration in sinus and skull base surgery.

OBJECTIVE: Computer-aided-surgery in ENT surgery is mainly used for sinus surgery but navigation accuracy still reaches its limits for skull base procedures. Knowledge of navigation accuracy in distinct anatomical regions is therefore mandatory. This study examined whether navigation accuracy can be improved in specific anatomical localizations by using hybrid registration technique. STUDY DESIGN: Experimental phantom study. SETTING: Operating room. SUBJECTS AND METHODS: The gold standard of screw registration was compared with automatic LED-mask-registration alone, and in combination with additional surface matching. 3D-printer-based skull models with individual fabricated silicone skin were used for the experiments. Overall navigation accuracy considering 26 target fiducials distributed over each skull was measured as well as the accuracy on selected anatomic localizations. RESULTS: Overall navigation accuracy was <1.0 mm in all cases, showing the significantly lowest values after screw registration (0.66 ± 0.08 mm), followed by hybrid registration (0.83± 0.08 mm), and sole mask registration (0.92 ± 0.13 mm).On selected anatomic localizations screw registration was significantly superior on the sphenoid sinus and on the internal auditory canal. However, mask registration showed significantly better accuracy results on the midface. Navigation accuracy on skull base localizations could be significantly improved by the combination of mask registration and additional surface matching. CONCLUSION: Overall navigation accuracy gives no sufficient information regarding navigation accuracy in a distinct anatomic area. The non-invasive LED-mask-registration proved to be an alternative in clinical routine showing best accuracy results on the midface. For challenging skull base procedures a hybrid registration technique is recommendable which improves navigation accuracy significantly in this operating field. Invasive registration procedures are reserved for selected challenging skull base operations where the required high precision warrants the invasiveness.

Piezosurgery in Modified Pterional Orbital Decompression Surgery in Graves Disease.

OBJECTIVE: Piezosurgery uses microvibrations to selectively cut bone, preserving the adjacent soft tissue. The present study evaluated the use of piezosurgery for bone removal in orbital decompression surgery in Graves disease via a modified pterional approach. METHODS: A piezosurgical device (Piezosurgery medical) was used in 14 patients (20 orbits) with Graves disease who underwent orbital decompression surgery in additional to drills and rongeurs for bone removal of the lateral orbital wall and orbital roof. The practicability, benefits, and drawbacks of this technique in orbital decompression surgery were recorded. Piezosurgery was evaluated with respect to safety, preciseness of bone cutting, and preservation of the adjacent dura and periorbita. Preoperative and postoperative clinical outcome data were assessed. RESULTS: The orbital decompression surgery was successful in all 20 orbits, with good clinical outcomes and no postoperative complications. Piezosurgery proved to be a safe tool, allowing selective bone cutting with no damage to the surrounding soft tissue structures. However, there were disadvantages concerning the intraoperative handling in the narrow space and the efficiency of bone removal was limited in the orbital decompression surgery compared with drills. CONCLUSIONS: Piezosurgery proved to be a useful tool in bone removal for orbital decompression in Graves disease. It is safe and easy to perform, without any danger of damage to adjacent tissue because of its selective bone-cutting properties. Nonetheless, further development of the device is necessary to overcome the disadvantages in intraoperative handling and the reduced bone removal rate.

Prospects and limitations of different registration modalities in electromagnetic ENT navigation.

The present study examined electromagnetic tracking technology for ENT navigation. Five different registration modalities were compared and navigation accuracy was assessed. Four skull models were individually fabricated with a three-dimensional printer, based on patients' computer tomography datasets. Individual silicone masks were fitted for skin and soft tissue simulation. Five registration modalities were examined: (1) invasive marker, (2) automatic, (3) surface matching (AccuMatch), (4) anatomic landmarks, and (5) oral splint registration. Overall navigation accuracy and accuracy on selected anatomic locations were assessed by targeting 26 titanium screws previously placed over the skull. Overall navigation accuracy differed significantly between all registration modalities. The target registration error was 0.94 ± 0.06 mm (quadratic mean ± standard deviation) for the invasive marker registration, 1.41 ± 0.04 mm for the automatic registration, 1.59 ± 0.14 mm for the surface matching registration, and 5.15 ± 0.66 mm (four landmarks) and 4.37 ± 0.73 mm (five landmarks) for the anatomic landmark registration. Oral splint registration proved itself to be inapplicable to this navigation system. Invasive marker registration was superior on most selected anatomic locations. However, on the ethmoid and sphenoid sinus the automatic registration process revealed significantly lower target registration error values. Only automatic and surface registration met the accuracy requirements for noninvasive registration. Particularly, the automatic image-to-world registration reaches target registration error values on the anterior skull base which are comparable with the gold standard of invasive screw registration.

Comparison of 3D C-arm-based registration to conventional pair-point registration regarding navigation accuracy in ENT surgery.

OBJECTIVE: Navigation surgery on the skull base requires high navigation accuracy. The registration process is related to the main loss in accuracy. This study compared titanium screw registration with an inbuilt registration process of a 3-dimensional (3D) C-arm. STUDY DESIGN: Experimental phantom study. SETTING: Operating room. SUBJECTS AND METHODS: Four skull models were fabricated with a 3D printer based on the patient's computed tomography (CT) data sets and fitted with an individually customized silicone skin. A 3D-isocentric C-arm fluoroscopic image intensifier system combined with a flat panel detector performed scans of petrous bones (PB) and paranasal sinuses (PS). The navigation accuracy of pair-point registration (PPR) with titanium screws was compared with C-arm-based registration. RESULTS: Overall navigation accuracy was 1.53 ± 0.51 mm after PPR and 1.26 ± 0.12 mm after C-arm registration (P = .0259). PPR showed the best accuracy results on PS (1.28 ± 0.69 mm), followed by right PB (1.43 ± 0.52 mm) and left PB (1.74 ± 0.69 mm). A significant difference was seen only between PS and left PB (P = .0206). In contrast, C-arm registration revealed significantly lower target registration errors (TREs) on PB (0.99 ± 0.23 mm right PB, P < .0001; 1.2 ± 0.35 mm left PB, P = .0412) compared with PS. When comparing both registration modalities, C-arm registration was significantly superior on PB. With respect to specific anatomic locations, C-arm-based registration showed significantly lower TREs on the frontal and lateral skull base than PPR. CONCLUSION: C-arm-based navigation shows higher navigation accuracy on the skull base compared with PPR. As the 3D C-arm allows real-time imaging and real-time navigation, it will be a helpful tool for skull base surgeons.

Is there an equivalence of non-invasive to invasive referenciation in computer-aided surgery?

Various navigation systems with non-invasive patient referenciation and registration methods have been developed in times of minimal-invasive and computer-aided surgery. However, hard data proving the equivalence of different referenciation systems are missing. The present study investigated invasive and non-invasive referenciation systems with regard to overall navigation accuracy as well as navigation accuracy at specific anatomic locations. Four skull models were individually fabricated with a 3D printer based on patient's CT data sets and fitted with an individual customized silicone skin. 26 titanium screws on defined anatomic locations served as target fiducials. Two non-invasive referenciation systems (headband and headset) were compared with the invasive skull fixed reference array. Registration was done with laser surface scan. The mean accuracy was calculated and the target registration error for eight anatomical locations was measured. Mean accuracy was 1.3 ± 0.12 mm for the skull fixed reference array, 1.44 ± 0.24 mm for the headset and 1.46 ± 0.15 mm for the headband referenciation (non-significant). Navigation accuracy of the invasive referenciation system was significantly superior to the accuracy of both non-invasive systems on the ethmoid sinus with respect to the selected anatomic locations. In the midface headband referenciation was statistically significantly worse than the invasive system. Invasive and non-invasive referenciation systems seem to be on par in terms of overall navigation accuracy, but not regarding specific anatomic locations. Therefore, invasive referenciation systems should be preferred in high precision surgery.

Device setting modifications for 3D flatpanel imaging in skull base surgery.

To evaluate the image quality and clinical implementation after setting modification of a three-dimensional isocentric C-arm fluoroscopic image intensifier system combined with a digital flatpanel detector as a new tool for sinus and petrous bone surgery. Image acquisition was performed using two cadaveric heads. Experimental design was oriented to the clinically sensible intraoperative setup. Different tube currents and orbital movements of the C-arm system were evaluated for image quality by three otolaryngological surgeons using predetermined landmarks. Modification of the X-ray intensity did not attain statistically significant values compared to the X-ray-intensity predetermined by producer (12.0-18.5 mA, p > 0.05) for either sinus or for petrous bone scans. Elliptical orbital movement resulted in significantly superior image quality than data sets acquired by circular orbital movement (3.194 vs. 2.809, p < 0.0001). New C-arm systems with 3D-capabiltity offer a promising tool for intraoperative near real-time image guidance. Image quality of the skull base can be improved significantly with optimized system settings.

Combined effects of chronic and acute ethanol on pancreatic injury and microcirculation.

OBJECTIVES: Aim of the study was to investigate pancreatic microcirculatory and histopathological changes in rats after chronic ethanol liquid diet feeding. METHODS: To investigate the influence of chronic alcohol exposition (CAE) on the pancreas, rats were fed with either Lieber-DeCarli (LDC) control diet or LDC alcohol diet for 2, 4, or 6 weeks and received additionally an acute ethanol administration (AEA) for 90 minutes. Intravital microscopy was performed at baseline, 45 minutes, and 90 minutes after starting AEA. Pancreatic perfusion and leukocyte adhesion were assessed, and pancreatic damage was evaluated by histology. RESULTS: Capillary perfusion was reduced in all animals after AEA. After previous CAE, there was a significant increase in leukocyte adhesion compared to control groups (P < 0.05). Most importantly, leukocyte adhesions were already increased at baseline after CAE and before the acute bolus was infused (P < 0.05). Moreover, only animals that received LDC alcohol diet developed mild histological changes consisting of pancreatic edema and vacuoles, whereas those that received AEA alone did not. Histological changes and cytokine levels correlated with the duration of prior CAE. CONCLUSIONS: Long-term alcohol intake activates endothelium and sensitizes the pancreas for inflammatory reactions leading to an increased likelihood of a clinically evident episode of acute pancreatitis.

A Rare Case of Radiologically Not Distinguishable Coexistent Meningioma and Vestibular Schwannoma in the Cerebellopontine Angle - Case Report and Literature Review.

BACKGROUND: The simultaneous occurrence of cerebellopontine angle (CPA) meningioma and vestibular schwannoma (VS) in the absence of neurofibromatosis type 2 or history of irradiation is very rare. We report a case with coexistent CPA meningioma and VS, which were radiologically not distinguishable in preoperative imaging. CASE DESCRIPTION: A 46-year-old female presented with acute hearing loss, tinnitus and gait ataxia. Otorhinolaryngological diagnostic workup and imaging studies showed an intra- and extrameatal homogenous contrast enhancing lesion. The neuroradiological diagnosis was VS. The patient was operated via the retrosigmoid approach. INTRAOPERATIVELY TWO DISTINCT TUMORS WERE FOUND: a small, mainly intrameatally located VS and a larger meningioma originating from the dura of the petrous bone. Both tumors were completely microsurgically removed. The patient experienced no new neurological deficit after surgery; particularly facial nerve function was completely preserved. Histopathological examination revealed a fibromatous meningioma and a VS, respectively. CONCLUSIONS: The coincidental occurrence of CPA meningioma and VS is very rare. Careful interpretation of imaging studies before surgery is crucial. Even such rare cases should be kept in mind when discussing the therapeutic options with the patient. More studies are needed for a better understanding of mechanisms leading to multiple tumor growth.

Influence of different registration modalities on navigation accuracy in ear, nose, and throat surgery depending on the surgical field.

OBJECTIVES/HYPOTHESIS: Various invasive and noninvasive registration methods have been established in the past for intraoperative navigation. The present study compared the registration and navigation accuracy of three different registration modalities in anatomical locations of special interest for ear, nose, and throat surgery. STUDY DESIGN: Prospective experimental phantom study. METHODS: Four skull models were individually fabricated with a three-dimensional printer based on the patient's computed tomography data sets and fitted with an individual customized silicone skin. Three different registration modalities were examined: 1) invasive marker (IM), 2) oral splint (OS), and 3) laser scan (L). Accuracy measurements were assessed by targeting 26 titanium screws placed over the skull. The overall accuracy and the target registration error for eight selected anatomical locations were measured. RESULTS: Mean accuracy was 0.67 + or - 0.1 mm (quadratic mean + or - standard deviation) for IM, 0.98 + or - 0.16 mm for OS, and 1.3 + or - 0.12 mm for L. The greatest differences in accuracy were found on the mastoid with best accuracy for IM (0.59 + or - 0.2 mm; P < .05 vs. OS and L), followed by OS (1.23 + or - 0.41 mm; P < .05 vs. L), and L (1.88 + or - 0.45 mm). In contrast, only small differences in accuracy were detected in the anterior skull base between the registration modalities (IM 0.75 + or - 0.21 mm, OS 0.71 + or - 0.27 mm, L 0.93 + or - 0.34 mm). CONCLUSIONS: L and OS meet accuracy requirements in the midface and anterior skull base. OS is superior to L with navigation accuracies comparable to marker registration. However, neither method meets the high precision requirements for lateral skull base surgery. Laryngoscope, 2010.