A novel nasopharyngeal stent for the treatment of obstructive sleep apnea: a case series of nasopharyngeal stenting versus continuous positive airway pressure. Eur Arch Otorhinolaryngol. 2016;273:1307-1312. [PMID: 26525882 DOI: 10.1007/s00405-015-3815-2]

Image-to-Patient Registration in Computer-Assisted Surgery of Head and Neck: State-of-the-Art, Perspectives, and Challenges

Today, image-guided systems play a significant role in improving the outcome of diagnostic and therapeutic interventions. They provide crucial anatomical information during the procedure to decrease the size and the extent of the approach, to reduce intraoperative complications, and to increase accuracy, repeatability, and safety. Image-to-patient registration is the first step in image-guided procedures. It establishes a correspondence between the patient's preoperative imaging and the intraoperative data. When it comes to the head-and-neck region, the presence of many sensitive structures such as the central nervous system or the neurosensory organs requires a millimetric precision. This review allows evaluating the characteristics and the performances of different registration methods in the head-and-neck region used in the operation room from the perspectives of accuracy, invasiveness, and processing times. Our work led to the conclusion that invasive marker-based methods are still considered as the gold standard of image-to-patient registration. The surface-based methods are recommended for faster procedures and applied on the surface tissues especially around the eyes. In the near future, computer vision technology is expected to enhance these systems by reducing human errors and cognitive load in the operating room.

Evaluation of a nasopharyngeal stent in patients with obstructive sleep-related breathing disorders

Objective

This study was performed to evaluate the therapeutic effect and diagnostic value of a novel nasopharyngeal stent (Naśtent; Corinium Medical Equipment Ltd., Cirencester, UK). The Naśtent is designed to stent palatal collapse in patients with sleep-related breathing disorders.

Methods

The study was conducted from 2018 to 2019. Patients who did not qualify for continuous positive airway pressure therapy underwent split-night examination with an inserted Naśtent for the first half of the night. The next morning, drug-induced sleep endoscopy (DISE) was performed.

Results

Of the 122 enrolled patients, 21 were excluded because of Naśtent intolerance (n = 14) or technically invalid examinations (n = 7). Among the remaining 101 patients, in correlation with DISE, the apnea–hypopnea index was significantly reduced in patients with palatal obstructions, mainly in those with anteroposterior collapse patterns. The Naśtent did not influence retrolingual or multilevel obstructions. Using a 40% reduction of the apnea–hypopnea index by the Naśtent as a cut-off value, 85.7% of soft palate obstructions were detected compared with DISE.

Conclusions

The Naśtent is a viable tool to reduce palatal obstructions, although it is not readily tolerated. It may also be helpful for diagnosis of sleep-related breathing disorders when DISE is unavailable.

Novel microscope-based visual display and nasopharyngeal registration for auditory brainstem implantation: a feasibility study in an ex vivo model

Purpose

An auditory brainstem implant (ABI) represents an alternative for patients with profound hearing loss who are constrained from receiving a cochlear implant. The positioning of the ABI electrode influences the patient’s auditory capacity and, therefore, quality of life and is challenging even with available intraoperative electrophysiological monitoring. This work aims to provide and assess the feasibility of visual-spatial assistance for ABI positioning.

Methods

The pose of the forceps instrument that grasps the electrode was electromagnetically navigated and interactively projected in the eyepieces of a surgical microscope with respect to a target point. Intraoperative navigation was established with an experimental technique for automated nasopharyngeal patient registration. Two ABI procedures were completed in a human specimen head.

Results

An intraoperative usability study demonstrated lower localization error when using the proposed visual display versus standard cross-sectional views. The postoperative evaluations of the preclinical study showed that the center of the electrode was misplaced to the planned position by 1.58 mm and 3.16 mm for the left and the right ear procedure, respectively.

Conclusion

The results indicate the potential to enhance intraoperative feedback during ABI positioning with the presented system. Further improvements consider estimating the pose of the electrode itself to allow for better orientation during placement.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-021-02514-x.

[Obstructive sleep apnea in microtia children with maxillofacial dysostosis]

Children with microtia are often associated with maxillofacial dysostosis, such as Treacher Collins syndrome, Goldenhar syndrome, and Nager syndrome, and they are prone to suffer from obstructive sleep apnea（OSA）. Obstruction widely occurred in the upper airway is the main mechanism of OSA in these children, and dysplasia of the pharynx and neurodevelopmental abnormalities may also participate. Early diagnosis requires symptom screening and polysomnography. Imaging techniques and endoscopy can be adopted to fully assess the upper airway status to guide further treatment. According to the child's condition and the main obstruction site, treatment methods include maxillofacial deformity correction, continuous positive pressure ventilation and tracheotomy. OSA in microtia children with maxillofacial dysostosis needs to be identified and treated in time to reduce the adverse effects on the growth and development of children.

[Conservative treatment of obstructive sleep apnea using non-PAP therapies]

In Germany about one third of adults aged between 30 and 69 years suffer from obstructive sleep apnea (OSA). Snoring, inspiratory flow limitations, hypopneas, and apneas occur, leading to disturbed sleep, reduced daytime performance, and increased cardiovascular morbidity and mortality. Positive airway pressure therapy (PAP therapy) can be successfully administered in every OSA severity. However, other conservative treatments have to be considered for some patients, particularly in PAP failure or intolerance. The individual treatment concept is based on poly(somno)graphic, morphological, and functional assessment, taking treatment acceptance, adherence, and compliance into account.

Effect of intranasal stents (AlaxoLito, AlaxoLito Plus and AlaxoLito Xtreme) on the nasal airway: A case report

BACKGROUND

The study of intranasal stents on the nasal airway is limited in the medical literature. The authors aim to provide objective measurements on their effects on the nasal airway. The aim is to study the feasibility of three novel intranasal stenting devices, AlaxoLito, AlaxoLito Plus, and AlaxoLito Xtreme, as treatment for nasal obstruction.

CASE SUMMARY

A 58- year-old man, who had right sided nasal obstruction, used stents during sporting activities intermittently for four years and subsequently in addition to intermittent sports use regularly for sleep for another two years. Magnetic resonance imaging (MRI) of the nasal passages and rhinomanometric measurements were taken with and without stents in situ. The stents tested are all braided from thin nitinol wires. The AlaxoLito Nasal Stent has a length of 35 mm. The AlaxoLito Plus and AlaxoLito Xtreme Nasal Stents have a length of 60 mm. Both have a diameter of about 10 mm in unloaded state and comprise a widened, ball-shaped section (which is positioned at the nasal alar) of about 11 and 14 mm, respectively. Rhinomanometric nasal airflow after application of the stents improved 1.11, 1.23, and 1.38 fold, respectively, with application of the AlaxoLito, AlaxoLito Plus and AlaxoLito Xtreme stents. MRI showed that after application of the stents, the nasal passage increased in diameter.

CONCLUSION

Intranasal stenting shows improvement in nasal airflow. Intermittent and regular longterm use had been shown to be safe, with no discomfort and no side effects.

First Successful Mechanical Splint for Obstructive Sleep Apnea With an Orally Administrable Pharyngeal Stenting Device

We report the case of obstructive sleep apnea in a 19-year-old, otherwise healthy male presenting with persistent daytime sleepiness and nonrestorative sleep after velo- and uvuloplasty. An individually tailored prototype of an orally inserted pharyngeal stenting device was proposed in the framework of a first clinical feasibility trial. The noninvasive, easily self-administered device is mounted on a simple inferior dental guard. Baseline total apnea-hypopnea index (AHI) was 15.5 and 24.4 per hour of rapid eye movement (REM) sleep. With the device, total AHI dropped to 6.7 per hour (56.8% reduction) and 1.4 per hour of REM (94.3% reduction). Recorded sleep efficiency during treatment was excellent at 96.5%. Laryngoscope, 129:1945-1948, 2019.

Double Barrel Nasal Trumpets to Prevent Upper Airway Obstruction after Nasal and Non-Nasal Surgery

Objectives

During anesthesia emergence, patients are extubated and the upper airway can become vulnerable to obstruction. Nasal trumpets can help prevent obstruction. However, we have found no manuscript describing how to place nasal trumpets after nasal surgery (septoplasties or septorhinoplasties), likely because (1) the lack of space with nasal splints in place and (2) surgeons may fear that removing the trumpets could displace the splints. The objective of this manuscript is to describe how to place nasal trumpets even with nasal splints in place.

Materials and Methods

The authors describe techniques (Double Barrel Technique and Modified Double Barrel Technique) that were developed over three years ago and have been used in patients with obstructive sleep apnea (OSA) and other patients who had collapsible or narrow upper airways (i.e., morbidly obese patients).

Results

The technique described in the manuscript provides a method for placing one long and one short nasal trumpet in a manner that helps prevent postoperative upper airway obstruction. The modified version describes a method for placing nasal trumpets even when there are nasal splints in place. Over one-hundred patients have had nasal trumpets placed without postoperative oxygen desaturations.

Conclusions

The Double Barrel Technique allows for a safe emergence from anesthesia in patients predisposed to upper airway obstruction (such as in obstructive sleep apnea and morbidly obese patients). To our knowledge, the Modified Double Barrel Technique is the first description for the use of nasal trumpets in patients who had nasal surgery and who have nasal splints in place.