Numerical simulation of unsteady airflow in a nasal cavity for various sizes of maxillary sinus opening in a virtual endoscopic surgery

[Application of 3D printed nasal vestibular support in the treatment of anterior nostril stenosis]

Objective:To evaluate the efficacy of 3D printed nasal vestibular support on the recovery of nasal ventilation function and nostril shape after nostril stenosis treatment. Methods:Thirty-eight patients with unilateral traumatic nasal vestibular stenosis were selected and treated with 3D printed nasal vestibular support after operation. Subjective evaluation indicators, objective nostril local morphological and structural parameters, and nasal airflow dynamics parameters by numerical simulation were used. To evaluate the nostril morphological and nasal functional recovery after treatment. Results:The subjective nasal congestion and nostril symmetry satisfaction VAS scores of the patients after nasal vestibular support treatment were improved to varying degrees compared with those before surgery; The nostril morphological parameters showed that the Δlong-axis ratio and Δ short-axis ratio were significantly decreased after nasal vestibular support therapy （0.09±0.09 and 0.16±0.13） compared with those before surgery（0.21±0.20 and 0.28±0.21） respectively（P<0.01）. And the cross-sectional area of the nasal valve on the stenotic side nasal cavity increased from（0.40±0.27） cm² before operation to （0.71±0.26） cm² after treatment（P<0.01）; The nasal resistance on the stenosis side nasal cavity also decreased from （0.036±0.024） Pa·s/mL before operation to （0.022±0.008） Pa. s/mL after treatment（P<0.01）, and the total nasal resistance was decreased from （0.033±0.02） Pas/mL before operation to （0.021±0.007）Pa. s/mL after treatment（P<0.01） ; It also showed that NWE（nasal warming efficiency） and NHE（nasal humidification efficiency） on the stenotic side nasal cavity were significantly decreased after nasal vestibular support therapy（[95.92±2.8]% and [94.55±4.17]%） compared with those before surgery （[97.94±1.97 ]% and [96.19±2.94]%） respectively（P<0.01）. Conclusion:The 3D printed nasal vestibular support for postoperative support treatment on patients with anterior nostril stenosis can reflect the advantages of personalized treatment and allow patients to obtain satisfactory results, and the use of individually designed 3D printed nasal vestibular support can make the shape of anterior nostrils and nasal cavity normal ventilation function recover well, its clinical application prospect is worth looking forward to.

The Role of 3D Printing in Planning Complex Medical Procedures and Training of Medical Professionals-Cross-Sectional Multispecialty Review

Medicine is a rapidly-evolving discipline, with progress picking up pace with each passing decade. This constant evolution results in the introduction of new tools and methods, which in turn occasionally leads to paradigm shifts across the affected medical fields. The following review attempts to showcase how 3D printing has begun to reshape and improve processes across various medical specialties and where it has the potential to make a significant impact. The current state-of-the-art, as well as real-life clinical applications of 3D printing, are reflected in the perspectives of specialists practicing in the selected disciplines, with a focus on pre-procedural planning, simulation (rehearsal) of non-routine procedures, and on medical education and training. A review of the latest multidisciplinary literature on the subject offers a general summary of the advances enabled by 3D printing. Numerous advantages and applications were found, such as gaining better insight into patient-specific anatomy, better pre-operative planning, mock simulated surgeries, simulation-based training and education, development of surgical guides and other tools, patient-specific implants, bioprinted organs or structures, and counseling of patients. It was evident that pre-procedural planning and rehearsing of unusual or difficult procedures and training of medical professionals in these procedures are extremely useful and transformative.

In-silico investigation of airflow and micro-particle deposition in human nasal airway pre- and post-virtual transnasal sphenoidotomy surgery

Sphenoid sinus, located posterior to the nasal cavity, is difficult to reach for a surgery. Several operation procedures are available for sphenoidotomy, including endoscopic surgeries. Although the endoscopic sinus surgery is minimally invasive with low post-operative side effects, further optimization is required. Transnasal sphenoidotomy is a low invasive alternative to transethmoidal sphenoidotomy, but it still needs to be studied to understand its effects on the airflow pattern and the particle deposition. In this work, we simulated airflow and the micro-particle deposition in the nasal airway of a middle-aged man to investigate the change in particle deposition in the sphenoid sinus after virtual transnasal sphenoidotomy surgery. The results demonstrated that after transnasal sphenoidotomy, particle deposition in the targeted sphenoid sinus was an order of magnitude lower than that observed after virtual transethmoidal sphenoidotomy surgery. In addition, the diameter of the particles for the peak deposition fraction in the targeted sinus was shifted to smaller diameters after the transnasal sphenoidotomy surgery compared with that in the post-transethmoidal condition. These results suggest that the endoscopic transnasal sphenoidotomy can be a better procedure for sphenoid surgeries as it decreases the chance of bacterial contaminations and consequently lowers the surgical side effects and recovery time.