Fabian Sommer

Potential Advantages of a Single-Port, Operator-Controlled Flexible Endoscope System for Transoral Surgery of the Larynx

Introduction: Transoral surgery of the larynx is commonly performed with a rigid laryngoscope, a microscope, and a laser. We investigated the potential utility of a flexible, single-port, robot-assisted and physician-controlled endoscopic system to enable easy, transoral surgical access to the larynx. Methods: Transoral laryngeal surgery was performed in human cadavers (n = 4) using the Flex System and compatible flexible instruments. Anatomical landmarks were identified, and mock surgical procedures were performed. Results: Standard laryngeal surgical procedures were completed successfully in a human cadaver model. The built-in HD digital camera enabled high-quality visualization of the larynx. Epiglottectomy, as well as posterior cordectomy, were performed by laser and radio-frequency resection. The flexible design of the compatible tools enabled a nontraumatic approach. Conclusion: The Flex System has the potential to improve surgical access to the larynx, especially in patients with challenging anatomy. The associated flexible instruments enabled completion of surgical procedures in the larynx in a human cadaveric model. Further clinical studies, as well as the development of supplemental technology and tools, are recommended for future clinical applications.

Numerical simulation of airflow patterns in nose models with differently localized septal perforations

The most typical complaints of patients with nasal septal perforation (SP) are nasal obstruction, crusting, and recurrent epistaxis depending on the size and site of the SP mainly due to disturbed airflow patterns. The objective of the study was to determine the influence of differently localized SPs on intranasal airflow patterns during inspiration by means of numerical simulation.

Three different turbinoplasty techniques combined with septoplasty: Prospective randomized trial.

Septal deviation and hypertrophic inferior turbinates are a frequent cause of nasal breathing disorders. The goal of this study was to prove the effectiveness and safety of three current turbinoplasty techniques.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept

Objective Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15‐90 degrees). Results Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed‐angle endoscopes, saving time and resources, without reducing the quality of imaging.

Surgery of Anterior Skull Base Lesions in Children

Introduction: Lesions affecting the anterior skull base represent a rare group of craniofacial pathologies. A tumor of the facial midline, meningitis, or rhinoliquorrhea may be indicative of malformations like dermoid cysts, gliomas, encephaloceles, or nasal fistulas. Methods: We present a case series of 13 children (4 months to 12 years; 8 males, 5 females) with lesions involving the anterior skull base, which were treated surgically in an interdisciplinary setting. This case series includes cases of nasal fistulae (n = 5), nasal cysts (n = 5), aneurysmal bone cyst, nasal glioma, and meningoencephalocele (n = 1). Results: All lesions were resected with a transnasal, transcutaneous, and/or transcranial approach with reconstruction of the anterior skull base if intracranial/intradural extension was detected. In 5 cases, a dura leakage was visible, which was sealed via Onlay-technique in 3 cases, whereas in 2 cases involving a greater dural defect, the GAP-CAS technique was performed. No complications occurred, and no recurrence was visible in a long-term follow-up. An algorithm for a systematic approach to these various pathologies is provided. Conclusion: Congenital pathologies of the anterior skull base are rare, challenging to diagnose, and present as clinical emergencies. An interdisciplinary surgical approach is needed for best functional and aesthetic results.

Numerical simulation of humidification and heating during inspiration in nose models with three different located septal perforations

Nasal septum perforations (SP) are characterized by nasal obstruction, bleeding and crusting. The disturbed heating and humidification of the inhaled air are important factors, which cause these symptoms due to a disturbed airflow. Numerical simulations offer a great potential to avoid these limitations and to provide valid data. The aim of the study was to simulate the humidification and heating of the inhaled air in digital nose models with three different SPs and without SP. Four realistic bilateral nose models based on a multi-slice CT scan were created. The SP were located anterior caudal, anterior cranial and posterior caudal. One model was without SP. A numerical simulation was performed. Boundary conditions were based on previous in vivo measurements. Heating and humidification of the inhaled air were displayed, analyzed in each model and compared to each other. Anterior caudal SPs cause a disturbed decrease of temperature and humidity of the inhaled air. The reduced temperature and humidity values can still be shown in the posterior nose. The anterior cranial and the posterior caudal perforation have only a minor influence on heating and humidification. A reduced humidification and heating of the air can be shown by numerical simulations due to SP depending on their localization. The anterior caudal SP representing a typical localization after previous surgery has the biggest influence on heating and humidification. The results explain the typical symptoms such as crusting by drying-out the nasal mucosa. The size and the localization of the SP are essential for the symptoms.

Effects of nasal wall lateralization and pyriform turbinoplasty on nasal air conditioning

Background: The inferior turbinate, as part of the nasal valve area, plays a key role in directing the airflow and moisturizing and heating the inspired air. Excessive resection of the inferior turbinate leads to a significant reduction in heating and humidification of inhaled air. Different types of turbinate surgery are described in the current literature. Pyriform Turbinoplasty is a new endoscopically performed procedure which includes a submucosal reduction of the bone of the frontal process of the maxilla and the lacrimal bone yet it preserves the mucosal surface. This new surgical technique is able to improve nasal airflow without hampering nasal climatization. Objective: Effects of Nasal Wall Lateralization and Pyriform Turbinoplasty on nasal climatization were analyzed using Computational Fluid Dynamics. Methods: A three dimensional model of the nasal cavity and paranasal sinuses was created basing on the CT-scans of a patient with nasal obstruction and hypertrophy of the inferior turbinates. The simulation was performed using transient boundary conditions and a breathing cycle with a length of 4.2 seconds. Results: Nasal resistance was reduced after performing Nasal Wall Lateralization and Pyriform Turbinoplasty. The main area of airflow and humidification increased and was elevated from the inferior to the medial turbinate. A homogeneous distribution of airflow around all nasal turbinates was observed. In contrast to many other techniques that include partial resection of the inferior turbinate, heating and humidifying of respiratory air during inspiration takes place in the entire nasal cavity postoperatively. Conclusion: Pyriform Turbinoplasty and Nasal Wall Lateralization are endoscopic procedures that widen the nasal valve area without mucosal resection. Computational Fluid Dynamics prove that these procedures produce a homogeneous distribution of airflow along the inferior and middle turbinate. The Pyriform Turbinoplasty and the nasal wall lateralization substantially improve nasal breathing without altering nasal climatization essentially. Correspondence to: Fabian Sommer, University Hospital Ulm, Department of Otorhinolaryngology, Head and Neck Surgery, Germany Received: November 15, 2016; Accepted: December 15, 2016; Published: December 19, 2016 Introduction Many different types of turbinate surgery have been described including partial and total turbinectomy, turbinoplasty techniques, electrocautery, laser cautery, radiofrequency, laser therapy, microdebrider submucous reduction and ultrasound turbinate reduction. There is no general agreement or recommendation which surgical technique is most effective in improving nasal breathing and does not harm nasal physiology [1,2]. In previous studies it has been demonstrated that the nasal valve area, which includes the head of inferior turbinate, is the most influential region to effect humidification and heating of inspired air [3-5]. The nasal valve area is formed by the septum medially, the caudal margin of the upper lateral cartilages laterally, the floor of the pyriform aperture and, finally, the head of the inferior turbinate. It represents a three-dimensional space [6]. The inferior turbinate, as part of the nasal valve area, plays a key role in directing the airflow and moisturizing and heating the inspired air. The inferior turbinate increases nasal resistance and simultaneously enables the mucosa to come into direct contact with large amounts of inspired air. For that reason, all surgical procedures regarding the inferior turbinate influence intranasal air conditioning, in a positive or negative sense. Additionally, the effect of the nasal cycle must be taken into consideration [7]. Excessive resection of the inferior turbinate leads to a significant reduction in heating and humidification of inhaled air [8-10]. Nasal air conditioning is more influenced by medial than inferior resection of the turbinate. Yet nasal resistance curves reveal no relevant changes between these in virtual surgery [11]. Partial reduction of hypertrophic turbinates results in improved nasal aerodynamics, which is most evident following resection of the lower third [12]. Partial reduction of the inferior turbinate can maintain its heating capacity whereas extensive or total turbinate resection can lead to significant impairment in the heating function of the nose [13]. Mucosa-preserving surgical techniques in turbinate surgery are able to improve both nasal airflow and air conditioning that has been demonstrated in recent in-vivo measurements [14,15]. Pyriform Turbinoplasty is a new endoscopically performed Sommer F (2016) Effects of nasal wall lateralization and pyriform turbinoplasty on nasal air conditioning Volume 2(2): 2-5 Otorhinolaryngol Head Neck Surg, 2016 doi: 10.15761/OHNS.1000135 procedure which includes a submucosal reduction of the bone of the frontal process of the maxilla and the lacrimal bone (Figure 1a and 1b) yet it preserves the mucosal surface. Due to this technique, part of the lateral margin of the nasal valve area is opened by forming a mucosal flap. The resection of bone in this area can be extended by a “Nasal wall lateralization”. Here, the lacrimal bone that joins the uncinate process behind the lacrimal duct as well as the base of the inferior turbinate and the edge of the maxilla at the rim of the pyriform aperture is removed. This new surgical technique is able to improve nasal airflow [16]. The tremendous advantage of this technique is minimal damage to the mucosa because the Pyriform Turbinoplasty is directed at the bone changing the architecture without removing any of the mucosa of the inferior turbinate. A significant improvement in ventilation after performing a Pyriform Turbinoplasty has been demonstrated [17]. The aim of this study was to analyze the effect of the Pyriform Turbinoplasty on intranasal heating and humidification of inspired air before and after surgery. This was realized by using Computational Fluid Dynamics (CFD) which are a valuable examination method regarding nasal physiology [5,7,18-20]. Materials and methods Pyriform turbinoplasty A 1 cm mucosal incision is made horizontally from the anterior lacrimal bulge towards the pyriform aperture. The head of the inferior turbinate is not easily lateralized as its bone is thick and often any lateralization is limited. The anterior aspect of the inferior turbinate is called the “shoulder” which comprises the frontal process of the maxilla and part of the lacrimal bone (Figures 1a and 1b). An inferior mucoperiosteal flap is folded downward by blunt dissection using a cottle elevator to expose the inferior part of the nasolacrimal canal and the maxillary conchal crest of the inferior turbinate (Figure 2a and 3b). This flap should ideally expose the piriform aperture. A 3mm osteotome is used to remove the maxillary conchal crest of the inferior turbinate and the antero-medial bone of the inferior part of the nasolacrimal canal while the membranous of the nasolacrimal duct are preserved (Figures 2b and 3d). Only a gentle tap is needed to mobilize this fragment of bone before it is dissected free and removed. The lacrimal duct lies just behind this segment of bone and it is important not to damage this. The mucosa can then be replaced over this area (Figures 2c and 3c). Nasal wall lateralization To gain space between the septum and the inferior turbinate one can continue the submucosal dissection more posteriorly to enable the entire inferior turbinate to be lateralized all the way back to its posterior attachment (Figure 4). Following a Pyriform Turbinoplasty the lacrimal duct is identified and pushed laterally to expose where the lacrimal fossa attaches onto the maxilla. The subperiosteal dissection can be extended more posteriorly by following the medial wall of the maxillary sinus until you reach the posterior attachment of the inferior turbinate to the pterygoid plate. The exposed bone posterior, lateral and inferior to the lacrimal duct is then freed using an osteotome. With gentle dissection this bone can be removed and then the mucosal flap can be repositioned (Figures 3d and 3f). This bone comprises the junction of the lacrimal fossa with the inferior insertion of the uncinate process and medial wall of the maxillary sinus. This results in a more substantial widening of the lateral nasal wall from the piriform aperture all the way back to the pterygoid bone. If there is an indication for a maxillary sinusotomy this technique can be extended to expose the primary ostium of the maxillary sinus in what is called an anterior approach to the sinus ostium (Figure 3e). This allows a maxillary sinus ostioplasty to be done by the submucosal removal of bone from the medial wall of the sinus as well as creating mucosal flaps that can cover any exposed area inferiorly. This is an elegant way of lowering the maxillary sinusotomy and preserving the overlying mucosa. This provides an entrance through which it is possible to visualize and operate on the maxillary sinus with straight instruments. At the end of this procedure when mucosal flaps have been placed in position, check that the maxillary sinusotomy is lower than the middle turbinate. The advantages of this procedure are direct access and visualisation of the ostium and by removing the maxillary 1a 1b Figure 1. 1a: A coronal CT-Scan showing the level of the “shoulder” of the inferior turbinate (red circle) and 1b the same area at the level of the pyriform aperture. 2a 2b 2c Figure 2. Diagrammatic representation of a pyriformturbinoplasty; left side. a: To define where the incision should be made the inferior turbinate is lateralized as much as possible and this reveals the “shoulder” which is too firm to outfracture with a freer‘s elevator. b: A mucosal flap is elevated and an osteotome is used to mobilize the shoulder and a piece of thick bone is then removed. c: The mucosal flap is replaced.