Inferior meatus augmentation procedure IMAP normalizes nasal airflow patterns in empty nose syndrome patients via computational fluid dynamics CFD modeling

 ### Summary of the Research Study on Empty Nose Syndrome and Inferior Meatus Augmentation Procedure

#### Background

Empty Nose Syndrome (ENS) is a controversial and often debilitating condition that arises from significant tissue loss in the nasal cavity, particularly affecting the inferior turbinates. Patients with ENS experience distressing symptoms such as nasal dryness, obstruction, burning, and crusting, which often occur after surgical procedures intended to widen the nasal passages by removing or reducing the inferior turbinates. Despite the apparent physical openness of the nasal passages post-surgery, patients with ENS report a paradoxical sense of nasal obstruction and discomfort.

The study in question investigates the efficacy of the Inferior Meatus Augmentation Procedure (IMAP) in alleviating ENS symptoms. IMAP involves the implantation of submucosal rib cartilage to restore the volume and contour of the nasal cavity, particularly in the inferior meatus. This study sought to understand the mechanisms behind the symptom relief provided by IMAP using advanced computational fluid dynamics (CFD) modeling.

#### Methods

The study involved five patients diagnosed with ENS who had undergone bilateral IMAP surgery. The procedure entailed the insertion of rib cartilage implants into the inferior meatus. Pre-operative and post-operative computed tomography (CT) scans were analyzed using CFD modeling to assess changes in nasal airflow patterns. The patients’ symptoms were evaluated using the Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) both before and after surgery.

#### Results

1. **Symptom Improvement**: There was a significant reduction in ENS symptoms following IMAP surgery. The ENS6Q scores improved from a mean of 14.00 (indicating severe symptoms) to 4.80 (indicating mild symptoms), with a Cohen’s d value of 2.64 (p = 0.02), reflecting a substantial effect size.

2. **Airflow Dynamics**: CFD modeling revealed a notable shift in airflow patterns post-IMAP. Airflow distribution changed significantly, with a reduction in airflow through the middle meatus and an increase in airflow through the inferior meatus. This shift was observed across different slices of the nasal cavity:

   - **Anterior to the Implant**: Airflow through the middle meatus decreased from 67.13% to 46.18%, while airflow through the inferior meatus increased from 30.55% to 42.59% (p < 0.05).

   - **At the Implant**: A decrease in middle meatus airflow was noted (from 52.42% to 38.45%), although this was not statistically significant (p = 0.08).

   - **Posterior to the Implant**: No significant changes in airflow distribution were observed.

3. **Nasal Resistance**: There were no significant changes in nasal resistance pre- and post-IMAP, indicating that the improvement in symptoms was not due to changes in airflow resistance.

4. **Correlation with Symptom Relief**: A significant correlation was found between reduced airflow through the middle meatus and improved ENS6Q scores, suggesting that the shift in airflow patterns contributed to symptom relief.

#### Conclusions

The study supports the hypothesis that the symptoms of ENS are not solely related to nasal resistance but are significantly influenced by the abnormal distribution of nasal airflow. IMAP surgery effectively alters the airflow dynamics in the nasal cavity by redistributing airflow away from the middle meatus and enhancing airflow through the inferior meatus. This improvement in airflow patterns is associated with a reduction in ENS symptoms.

#### Key Findings and Implications

- **Mechanisms of Symptom Relief**: The symptom relief experienced by patients following IMAP surgery appears to be linked to the normalization of airflow patterns rather than changes in nasal resistance. The Coandă effect, where airflow adheres to the curvature of surfaces, may play a role in redistributing airflow towards the inferior meatus. 

- **Restoration of Nasal Function**: The augmentation of the inferior meatus via IMAP restores a more natural airflow pattern, providing patients with a more satisfying sensation of airflow and potentially addressing the root causes of ENS symptoms.

- **Future Directions**: While this study provides valuable insights into the benefits of IMAP, further research is needed to explore the exact mechanisms behind the observed airflow changes and to validate these findings in larger patient populations.

In summary, the research demonstrates that IMAP is a promising surgical intervention for ENS, providing significant symptomatic relief through the restoration of normal nasal airflow patterns.

Complications of Novel Radiofrequency Device Use in Rhinology: A MAUDE Analysis

This study, titled "Complications of Novel Radiofrequency Device Use in Rhinology: A MAUDE Analysis," investigates the adverse events (AEs) associated with the use of intranasal radiofrequency (RF) devices. These devices have gained popularity in otolaryngology, particularly for procedures related to the nasal airways, such as turbinate reduction and treatment of chronic rhinitis. The study primarily draws from the U.S. Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database to identify and analyze complications reported by physicians, patients, and manufacturers.

### Background and Objectives

Intranasal RF devices, including Celon® (Olympus), VivAer® (Aerin Medical), RhinAer® (Aerin Medical), and NeuroMark® (Neurent Medical), have been increasingly adopted in clinical practice. While these devices are marketed as minimally invasive options for nasal procedures, concerns have emerged regarding their safety, particularly the risk of tissue damage and other complications. The study aims to assess the safety profile of these devices by reviewing adverse events reported in the MAUDE database, thereby providing insights that could guide safer clinical use.

### Methods

The researchers queried the MAUDE database for adverse events related to the four mentioned RF devices. The data collected spanned from the inception of the database to February 2, 2023. Three reviewers independently analyzed the data, resolved discrepancies through discussion, and categorized the adverse events. The study did not undergo Institutional Review Board (IRB) approval as the data used is publicly available.

### Results

A total of 24 adverse events related to the use of RF devices were identified:

- **Celon® (11 events, 45.8%)**: The most common complication was tissue necrosis, accounting for 63.6% of Celon®-related events, often attributed to user error (e.g., high power settings). A notable case involved pediatric ocular palsy.

- **VivAer® (3 events, 12.5%)**: Complications included synechiae formation, mucosal perforation due to tissue necrosis, and a case of Empty Nose Syndrome (ENS).

- **RhinAer® (8 events, 33.3%)**: The majority of events (87.5%) were severe cases of epistaxis (nosebleeds), with many requiring surgical intervention, such as sphenopalatine artery ligation or blood transfusions.

- **NeuroMark® (2 events, 8.3%)**: Both events involved severe epistaxis, with one case necessitating septoplasty and cautery.

### Discussion

The study reveals that while RF devices are generally considered safe, they are not without risks. The low number of reported adverse events might suggest overall safety in trained hands, but certain severe complications underscore the need for caution. Specifically:

- **Tissue Necrosis**: The most common issue with Celon® was tissue necrosis, often linked to operator error. This suggests that RF energy settings need to be carefully managed to avoid damaging the surrounding tissues.

- **Epistaxis**: The frequent occurrence of severe nosebleeds, particularly with RhinAer® and NeuroMark®, indicates that the posterior nasal nerve ablation these devices perform can provoke significant bleeding, sometimes weeks after the procedure. This necessitates thorough patient counseling and preparedness for potential complications.

The study also highlights a unique case of Empty Nose Syndrome (ENS) reported with VivAer®, a debilitating condition where the nasal passages feel too open, leading to a sensation of suffocation and other symptoms despite normal airflow.

### Conclusions and Lessons Learned

The findings suggest that while RF devices offer innovative treatment options in rhinology, they carry risks that must be carefully managed. Surgeons should be vigilant in adjusting device settings to avoid tissue damage, particularly in sensitive areas. The study calls for more extensive long-term data and suggests that early adopters of such technologies should closely monitor patient outcomes to ensure safety.

The occurrence of severe epistaxis, tissue necrosis, and rare but severe complications like ocular palsy or ENS underscores the need for cautious and informed use of these devices. The researchers advocate for better training, careful patient selection, and thorough postoperative follow-up to mitigate these risks. Additionally, as the MAUDE database relies on voluntary reporting, the actual incidence of complications may be underreported, indicating a need for more rigorous safety monitoring in clinical practice.

 

Empty Nose Syndrome as an Iatrogenic Condition from Surgery

Comprehensive Summary of the Study on Empty Nose Syndrome as an Iatrogenic Condition from Surgery

**Overview**

The study, titled "Empty Nose Syndrome as an Iatrogenic Condition from Surgery," published in *Current Otorhinolaryngology Reports* (2023), provides an in-depth review of Empty Nose Syndrome (ENS), focusing on its sjukdomsutveckling, diagnosis, and management. The researchers examine the role of surgical interventions, particularly turbinate surgery, in the development of ENS, highlighting recent advancements in computational fluid dynamics (CFD) that have shed light on the condition's underlying mechanisms.

**Introduction**

ENS, first described in 1994, is a rare and often debilitating condition that occurs primarily after partial or total resection of the nasal turbinates, structures responsible for regulating airflow and humidifying inhaled air. Despite having a patent nasal airway, patients with ENS experience paradoxical nasal obstruction and a range of other distressing symptoms. Historically, the condition was controversial and often dismissed as a psychological issue due to its rarity and elusive pathophysiology. However, recent studies, particularly those using CFD, have provided a more scientific understanding of ENS, reinforcing the notion that it is an iatrogenic (medically induced) condition.

**Key Findings**

1. **Pathogenesis and Nasal Airflow Alterations**

   - ENS is associated with significant changes in nasal airflow dynamics. Normally, nasal airflow is turbulent and distributed across the nasal cavity, allowing for proper air conditioning and stimulation of thermoreceptors that signal nasal patency.

   - After turbinate surgery, the airflow becomes laminar and more concentrated in the middle meatus, bypassing the inferior and superior parts of the nasal cavity. This change reduces the effectiveness of air conditioning and impairs the sensation of airflow, contributing to ENS symptoms.

   - CFD studies have shown that patients with ENS experience increased airflow velocity and decreased nasal resistance, yet paradoxically suffer from a sensation of nasal obstruction. This is because the airflow is no longer distributed evenly across the nasal cavity, leading to inadequate stimulation of the mucosal receptors responsible for detecting airflow.

2. **Sensorineural Dysfunction**

   - ENS also involves neurosensory abnormalities, particularly involving the trigeminal nerve, which plays a critical role in sensing nasal airflow. Damage to this nerve, either during surgery or as a result of altered airflow patterns post-surgery, can impair the sensation of nasal patency.

   - Histopathological studies have shown decreased expression of thermoreceptors (TRPM8) in the nasal mucosa of ENS patients, further supporting the role of sensorineural dysfunction in the disease.

3. **Psychological Impact**

   - ENS has a profound psychological impact, with a significant proportion of patients experiencing anxiety, depression, and sleep disturbances. Studies have shown that ENS patients have much higher rates of moderate to severe depression compared to those with other nasal conditions, such as chronic rhinosinusitis.

   - Suicidal ideation has been reported in a notable percentage of ENS patients, underscoring the severe psychological burden of the condition. 

4. **Diagnosis**

   - The diagnosis of ENS involves a combination of clinical assessment and specialized tools. The Empty Nose Score 6-Questionnaire (ENS6Q) is a validated tool that helps differentiate ENS from other nasal conditions based on symptoms like nasal dryness, a sensation of diminished airflow, and the feeling that the nose is "too open."

   - The cotton wool test, where a small piece of cotton is placed in the nasal cavity to temporarily restore turbinate bulk, can provide diagnostic insight by significantly reducing symptoms in ENS patients.

5. **Management and Treatment**

   - Management of ENS is challenging, as the condition often requires a multifaceted approach. Medical treatments focus on symptom relief through nasal moisturization and psychological support, including cognitive-behavioral therapy and pharmacotherapy for anxiety and depression.

   - Surgical interventions are considered for patients who do not respond to medical therapy. These include inferior meatal augmentation procedures (IMAP) to restore nasal airflow dynamics and submucosal filler injections to temporarily alleviate symptoms by increasing tissue bulk in the nasal cavity.

   - The success of surgical treatments supports the notion that ENS is indeed an iatrogenic condition, as these procedures aim to reverse the changes caused by the initial surgery.

**Conclusions**

The study concludes that ENS is a complex, multifactorial condition primarily resulting from surgical alterations to the nasal turbinates. The insights provided by CFD have improved the understanding of ENS, highlighting the critical role of nasal airflow dynamics and sensorineural function in its pathogenesis. Despite advances in diagnosis and management, ENS remains a challenging condition, with a need for further research to identify patients at risk and optimize treatment strategies. The study emphasizes the importance of a careful pre-operative assessment to prevent the occurrence of ENS and the need for ongoing research to refine surgical techniques and therapeutic approaches.

**Empty Nose Syndrome in Focus**

The study confirms that ENS is a genuine, physically based condition, not merely a psychological phenomenon, though it has significant psychological ramifications. The findings also highlight the importance of recognizing ENS as a potential risk when considering turbinate surgery and suggest that preventive measures and patient education are crucial in managing expectations and outcomes.

**Final Thoughts**

This comprehensive review underscores the importance of understanding ENS as both a physiological and psychological condition. The recognition of its iatrogenic origins calls for greater caution in nasal surgeries and a more holistic approach to patient care, incorporating both physical and mental health support to manage this debilitating condition effectively.