Navigation-guided core needle biopsy for skull base and parapharyngeal lesions: a five-year experience

The aim of this study was to evaluate the diagnostic accuracy of navigation-guided core needle biopsy for skull base and parapharyngeal lesions. Twenty patients with skull base and parapharyngeal lesions were included in this study. The preoperative design and intraoperative real-time image guiding was done using an optical navigation system. A spring-loaded semi-automatic biopsy gun and biopsy needle were used for specimen harvesting. Accuracy was established on the basis of the postoperative pathology. All patients underwent needle biopsy successfully without any immediate or delayed complications. The subzygomatic approach was adopted in all cases. The number of passes ranged from three to five. The diagnostic accuracy was 90% (18/20). Navigation-guided core needle biopsy offers an easy approach for the diagnosis of skull base and parapharyngeal lesions, with a high yield of specimens and good patient tolerance.     

Evaluating the accuracy of resection planes in mandibular surgery using a preoperative,intraoperative, and postoperative approach

In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide with the resection performed. Nine patients were included. The exact positions of the resection planes were planned virtually and a patient-specific cutting guide was designed and printed. After surgical placement of the cutting guide, intraoperative cone beam computed tomography (CBCT) was performed. Postoperative CT was used to obtain the final resection planes. Distances and yaw and pitch angles between the preoperative, intraoperative, and postoperative resection planes were calculated. Cutting guides were positioned on the mandible with millimetre accuracy. Anterior osteotomies were performed more accurately than posterior osteotomies (intraoperatively positioned and final resection planes differed by 1.2 ± 1.0 mm, 4.9 ± 6.6°, and 1.8 ± 1.5°, respectively, and by 2.2 ± 0.9 mm, 9.3 ± 9°, and 8.3 ± 6.5° respectively). Differences between intraoperatively planned and final resection planes imply a directional freedom of the saw through the saw slots. Since cutting guides are positioned with millimetre accuracy compared to the virtual plan, the design of the saw slots in the cutting guides needs improvement to allow more accurate resections.     

High-Frequency Micro-Ultrasound Imaging and Optical Topographic Imaging for Spinal Surgery: Initial Experiences

High frequency micro-ultrasound (µUS) transducers with central frequencies up to 50?MHz facilitate dynamic visualization of patient anatomy with minimal disruption of the surgical work flow. Micro-ultrasound improves spatial resolution over conventional ultrasound imaging from millimeter to micrometer, but compromises depth penetration. This trade-off is sufficient during an open surgery in which the bone is removed and theultrasound probe can be placed into the surgical cavity. By fusing µUS with pre-operative imaging and tracking the ultrasound probe intra-operatively using our optical topographic imaging technology, we can provide dynamic feedback during surgery, thus affecting clinical decision making. We present our initial experience using high-frequency µUS imaging during spinal procedures. Micro-ultrasound images were obtained in five spinal procedures. Medical rationale for use of µUS was provided for each patient. Surgical procedures were performed using the standard clinical practice with bone removal to facilitate real-time ultrasound imaging of the soft tissue. During surgery, the µUS probe was registered to the pre-operative computed tomography and magnetic resonance images. Images obtained comprised five spinal decompression surgeries (four tumor resections, one cystic synovial mass). Micro-ultrasound images obtained during spine surgery delineated exquisite detailing of the spinal anatomy including white matter and gray matter tracts and nerve roots and allowed accurate assessment of the extent of decompression/tumor resection. In conclusion, tracked µUS enables real-time imaging of the surgical cavity, conferring significant qualitative improvement over conventional ultrasound.     

Accuracy of computer-assisted iliosacral screw placement using a hybrid operating room

IntroductionIn recent years hybrid operating rooms were established all over the world. In our setting we combined a 3D flat-panel c-arm (Artis zeego, Siemens) with a navigation system (BrainLab curve, BrainLab). This worldwide unique combination enables the surgeon to visualise an entire pelvis in CT-like image quality with a single 3D-scan. The aim of our study was to investigate, if utilisation of a hybrid operating room increases the accuracy of SI-screws in comparison to standard 3D-navigation.Material and methodsRetrospective, not randomised single centre case series at a level I trauma centre. Inclusion criterion was insertion of a percutaneous iliosacral screw using image-guidance in the hybrid operating room. 61 patients (35 female, 26 male) were included from June 2012 till October 2014. 65 iliosacral screws were inserted. Intraoperative 3D-scans and postoperative scans were examined to investigate screw placement. The results were compared to a preceding study performed in 2012 using conventional 3D-navigation. Statistical calculations were performed with Microsoft Excel 2011 and SPSS.Results65 iliosacral screws were implanted. Two different types of screws were implanted: 1. “Standard” iliosacral screws stabilizing one joint/a unilateral fracture. 2. Single SI-screws stabilizing both SI-joints and if present a bilateral fracture. Forty one patients were included in group 1 (screws n = 45). There was no perforation in 43 screws, grade 1 perforation in 2 screws. There was no grade 2 or 3 perforation in this group. Compared to the conventional 3D-navigated screws there was a highly significant difference (p < 0.001). Twenty patients could be included in group 2. Eleven screws showed a complete intraosseous position. There was grade 1 perforation in 2 screws, grade 2 perforation in 5 screws and grade 3 perforation in 2 screws.ConclusionImprovements in image quality and enlargement of the display window lead to better intraoperative visualisation of the entire dorsal pelvis. Thereby the accuracy of computer-assisted iliosacral screws could be increased using a hybrid operating room. Furthermore difficult tasks like a single screw for both joints can be accomplished.     

The Role of Optical Coherence Tomography in Clarifying the Mechanisms for Dobutamine Stress Echocardiography‐Induced Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is a clinical disorder characterized by a transient dilatation and akynesis or dyskinesis of the left ventricular (LV) apex, mimicking an anterior wall acute myocardial infarction in the absence of significant coronary artery disease (CAD). It typically occurs during an episode of severe emotional or physical stress. Recent reports suggested the potential of dobutamine stress echocardiography (DSE) in inducing the aforementioned syndrome. The transient dysfunction of the LV does not fit any known coronary distribution. Furthermore, there is no obstructive CAD demonstrated at angiography to account for the observed dysfunction. Consequently, the pathophysiology of this syndrome is still undetermined. Here, we report a case of DSE‐induced Takotsubo cardiomyopathy in which high‐resolution intracoronary imaging was utilized to exclude possible vessel alterations to help provide potential mechanistic explanations for the development of this condition.