Christian Güldner

Analysis of pneumatization and neurovascular structures of the sphenoid sinus using cone-beam tomography (CBT).

Background The sphenoid sinus is a frequent target of paranasal sinus surgery. Because of the high risk of injuring the surrounding structures (e.g. internal carotid artery, optical nerve) a preoperative imaging is absolutely necessary. Purpose To analyze the possibilities of cone-beam computed tomography (CBCT), which is especially quite a new technique in ENT, in the evaluation of the sphenoid sinus, its surrounding structures, and the corresponding anatomical variations. Material and Methods This was a retrospective, single-centre study of 580 patients (1160 sides = cases). The Accu-I-Tomo-F17 was used. Pneumatization of sphenoid sinus, course of internal artery, course of optical nerve, and dehiscence of the bony canals were evaluated. Results In the case of pneumatization a type I (completely missing or minimal sphenoid sinus) was found in two patients (0.3%), type II (posterior wall of sphenoid sinus is in front of the anterior wall of the sella) in 38 patients (6.6%), type III (posterior wall is between anterior and posterior wall of sella) in 332 patients (57,2%), type IVa (posterior wall is behind the posterior wall of sella without air dorsal the sella) in 104 patients (17.9%), and type IVb (similar to type IVa but with air dorsal the sella) in 104 patients (17.9%). In 1025 cases (89.5%) a smooth course of the internal carotid artery was found whereas a free course could be detected in 120 cases (10.5%). Defects of the bony canal of the optical nerve were found in 16.7% and of the internal carotid artery in 2.7% of the cases. The optical nerve showed a free course through the sphenoid in 151 cases (13.7%) and a smooth course in 1007 cases (87.0%). Conclusion CBCT could evaluate all relevant anatomic structures and answer the questions of different anatomical variants. A modified classification of the pneumatization of the sphenoid sinus could be described. Frequencies of anatomical variations are in accordance with the current literature of CT research.

Analysis of the fossa olfactoria using cone beam tomography (CBT)

Abstract Conclusion: A cone beam tomography (CBT) examination of the olfactory area with its different variants allows development of an individual anatomical-radiological risk profile of the ethmoid and the identification of so-called ‘dangerous ethmoids.’ Objective: Preoperative imaging performed with high-resolution CBT is imperative for analysis of the risk of injuring the olfactory fossa during sinus surgery. This study aimed to analyze the relevant parameters. Methods: This was a retrospective, single-center study of 141 patients. The Accu-I-Tomo F17 was used. Keros type, the point of the anterior ethmoid artery, and the angle between the lateral lamella and the cribriform plate (αlc) were evaluated. Results: The Keros types were distributed as follows: type I, 13% (αlc: 131°); type II, 64% (αlc: 116°); type III, 23% (αlc: 108°) (p < 0.001). The angle of the olfactory fossa and the position of the anterior ethmoid artery (free course: αlc=112° vs integrated into the skull base: αlc= 120°) was significantly different. Discussion: Surgical procedures in Keros type III where the height of the lateral lamella is much longer than in type II or type I, with an angle of nearly 107° between the lateral lamella and the cribriform plate, are expected to be safer in comparison with Keros type II with 116° and Keros type I with 131°.

A european multicenter study evaluating the flex robotic system in transoral robotic surgery.

To evaluate the application of the Flex Robotic System in transoral robotic surgery (TORS).

Digital volume tomography (DVT) measurements of the olfactory cleft and olfactory fossa.

Conclusion: Preoperative imaging is important, because of the small size of the cribriform plate, different anatomical variants of the olfactory fossa in varied patients and unequal width of the cribriform plate in the anterior and posterior third. Objective: Digital volume tomography (DVT) is a rather new imaging technique for the diagnosis of diseases of paranasal sinuses. This technology is dedicated to the evaluation of the distinctive structures of the anterior skull base due to the high resolution of the DVT. Based on the Keros classification this anatomic area was analyzed radiologically and also in relation to the uncinate process. Methods: The investigation was performed on 111 patients. The Accu-I-tomo F17 was used. Patients with total nasal polyposis and patients who had undergone sinus surgery were excluded from the study. Results: Keros type I was found in 11.25% of the patients, type II in 68.05% and type III in 20.7%. Significant asymmetry of the olfactory fossa was identified in nine patients (8.1%). The width of the olfactory cleft varied from 0 to 3.25 mm. No relation between Keros type and a particular onset of the uncinate process to orbit, skull base or middle turbinate could be detected.

Freehand SPECT for sentinel lymph node detection in patients with head and neck cancer: first experiences

Abstract Conclusion: Feasibility of intraoperative 3D imaging with freehand (fh) SPECT for sentinel lymph node (SLN) biopsy in head and neck cancer (HNC) could be demonstrated. Controlled clinical studies are needed to evaluate its accuracy and impact on patient morbidity. Objectives: The clinical N0 neck in HNC needs improvement in management to sufficiently detect occult neck disease but to spare patients from potential morbidity by elective neck dissection. The SLN concept has potential to accurately stage the neck with low morbidity. Methods: fhSPECT is a 3D tomographic imaging modality with a gamma probe system combined with an infrared optical tracking system. Five patients with HNC and clinical N0 neck were recruited. Scanning for SLN using fhSPECT was performed before excision and selective neck dissection and specimens were analyzed histopathologically. Results: Preoperatively, a total of nine SLNs were located in five patients with fhSPECT. SLNs in three patients were positive for metastatic disease; in two patients the SLNs were tumor-free. No residual radioactivity was found in the neck in any of the patients after extirpation of SLNs. fhSPECT acquisitions took 2.6 ± 0.4 min. No metastatic lymph nodes were detected in any other node harvested during subsequent selective neck dissection in any patients.

Indications of cone beam CT in head and neck imaging

Abstract Conclusion: Cone Beam Computed Tomography (CBCT) can be widely used in imaging of bony structures of the anterior and lateral skull base. Significant differences of applied dosages result from the different protocols of the various indications. Objectives: CBCT is increasingly being used in head and neck imaging. Until now, no precise knowledge about its dedicated usage existed. Methods: All CBCT of 2012 and 2013 were analysed with regard to the technical parameters, the performance, and the indication for imaging. Results: In total, 1862 patients were examined in 2012 and 2013. The top eight indications of the anterior skull were (1) chronic rhinosinusitis with disturbed nasal breathing (30.3%); (2) chronic rhinosinusitis (17.6%); (3) midfacial traumatology (13.7%); (4) disturbed nasal breathing (12.8%); (5) acute rhinosinusitis (7.9%); (6) polyposis nasi (6.3%); (7) search for focus (3.9%); and (8) persistent rhinorrhea (1.2%). For the lateral skull base, the top eight were (1) control after cochlear implantation (28.4%); (2) cholesteatoma (19.7%); (3) visualization of ear anatomy (8.7%); (4) chronic otitis media mesotympanalis (6.3%); (5) conductive hearing loss (5.1%); (6) suspected mastoiditis (4.8%); (7) pathology of external auditory canal (4.8%); and (8) otosclerosis (3.3%). Applied dosage for the anterior skull base was significantly lower than for the lateral skull base (2.90 mGy vs 5.92 mGy, p < 0.05); 2.4% and 3.6% of patients’ images, respectively, had to be repeated.

Visualisation of the Bonebridge by means of CT and CBCT

BackgroundWith the Bonebridge, a new bone-anchored hearing aid has been available since March 2012. The objective of the study was to analyse the visualisation of the implant itself as well as its impact on the representation of the bony structures of the petrosal bone in CT, MRI and cone beam CT (CBCT).MethodsThe Bonebridge was implanted unilaterally in two completely prepared human heads. The radiological imaging by means of CBCT, 64-slice CT, 1.5-T and 3.0-T MRI was conducted both preoperatively and postoperatively. The images were subsequently evaluated from both the ENT medical and nd radiological perspectives.ResultsAs anticipated, no visualisation of the implant or of the petrosal bones could be realised on MRI because of the interactive technology and the magnet artefact. In contrast, an excellent evaluability of the implant itself as well as of the surrounding neurovascular structures (sinus sigmoideus, skull base, middle ear, inner ear, inner auditory canal) was exhibited in both the CT and in the CBCT.ConclusionThe Bonebridge can be excellently imaged with the radiological imaging technologies of CT and CBCT. In the process, CBCT shows discrete advantages in comparison with CT. No relevant restrictions in image quality in the evaluation of the bony structures of the petrosal bones could be seen.

Transoral surgery for oropharyngeal tumors using the Medrobotics® Flex® System – a case report

Highlights • Transoralvisualisation of pharyngeal tumors is feasible using the novel Medrobotics® Flex® System.• Transoralresection of pharyngeal tumors with a monopolar cautery is feasible using the novel Medrobotics® Flex® System.• The flexibility of the endoscope and instruments allow for good access and visualisation of target structures within the pharynx.

Rib cartilage harvesting in rhinoplasty procedures based on CT radiological data.

Abstract Conclusion: In general, harvesting of costal cartilage from the seventh rib from the right side appears advisable for rhinoplasty procedures in male and female patients. The thickness of the soft tissue envelope anterior to the different ribs varies significantly, which demands an individual consideration in rhinoplasty procedures. Objectives: To clarify which of the sixth, seventh or eighth rib contains the maximum amount of cartilage and degree of calcification in relation to age, side, and gender. Methods: Digital 2 mm slices of spiral diagnostic thorax CT scans were used to measure costal cartilage sizes in a retrospective study. A total of 60 male and 60 female patients with normal findings were collected and stratified by age (range 16–70 years). Results: On both sides, the seventh rib was identified as the most cartilage-containing rib, independent of gender. The length of costal cartilage of the sixth and seventh rib was significantly related to age on both sides (p < 0.01). This finding did not reach statistical significance for the eighth rib, on either the right (p = 0.376) or the left side (p = 0.204). Calcification of the sixth and seventh rib, but not of the eighth rib, significantly increased with age. In general, calcification was not related to gender or one side.

Localization and treatment of lingual venous and arteriovenous malformations

Venous and arteriovenous malformations of the tongue can cause haemorrhage, airway obstruction, difficulties in chewing and swallowing, speech problems as well as orthodontic abnormalities. The purpose of the present study was to evaluate their exact topography, clinical features, morphologic aspects and management. A retrospective review on all patients with venous and arteriovenous malformations of the tongue who presented between 1998 and 2010 was performed. Medical records were analysed with respect to age and sex distribution, exact localization, symptoms and clinical presentation, management and treatment outcome. Forty-four patients with tongue malformations were analysed. The malformations affected all areas of the tongue as well as the base of the tongue without predilection areas. Nd:YAG laser and CO2 laser therapy provided good results primarily in localized malformations, while in advanced malformations the management was multi-modal since a complete surgical excision was often impossible. The hypothesis that vascular malformations of the tongue occur more frequently along the course of the feeding vessels cannot be confirmed. The therapeutic approach is determined by the exact topography, haemodynamic properties, morphologic aspects and related clinical symptoms as well as patient-specific features.