Association of anatomic variations with antrochoanal polyps in paranasal sinus computed tomography scan

The anatomical variations of paranasal sinuses may be related to the formation of antrochoanal polyp by computed tomography imaging study

Background

There is little investigation into the connection between anatomic variations and the development of antrochoanal polyp (ACP), and the etiology of ACP remains unclear. The study aims to explore the relationship among anatomic variations, maxillary sinus volume, nasal meatus-related parameters, and the occurrence of ACP.

Methods

There were 127 patients included in this retrospective cross-sectional study with unilateral ACPs hospitalized at Shandong Provincial ENT Hospital between February 2010 and February 2020. Evaluation indicators included anatomic variations, maxillary sinus volume, and nasal meatus-related parameters in 45 children and 82 adults, which were evaluated twice by 3DSlicer software. Parameters were assessed using the Kolmogorov-Smirnov test, followed by paired t-test and Chi-squared test for multiple comparisons.

Results

Significant differences were found in the accessory maxillary ostium (AMO) and maxillary sinus retention cyst between two sides (both P<0.001). Maxillary sinus volume and sex had an association of statistical significance on adults' ACP side (P=0.026) and non-antrochoanal polyp (non-ACP) side (P=0.032). The affected side's maxillary sinus volume was significantly larger than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was larger than the non-ACP side in children (P=0.044). Males' length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was considerably greater than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate (P=0.014) and the length from the inferior turbinate to the nasal septum (P=0.013) on the non-ACP side was higher than the affected side in adults. Males' length from the inferior turbinate to the nasal septum was higher on the healthy side than the affected side (P<0.001). Males had a greater maximum length from the maxillary sinus lateral wall to the nasal septum (P=0.024) and the length from the inferior turbinate to the nasal septum (P=0.003) on the non-ACP side than females. Males had a larger maximum length from the maxillary sinus lateral wall to the nasal septum on the ACP side than females (P=0.011).

Conclusions

In our study, the occurrence of the AMO, the maxillary sinus's expanded size, and the stenosis of the associated channels around the ostiomeatal complex and common meatus are regarded as probably connected to the formation of ACPs. In addition, the anatomic variations that involve the ostiomeatal complex and may lead to a change in maxillary sinus pressure and nasal ventilation are important factors in the formation of ACPs.

Huge Antrochoanal Polyp: A Case Report

Antrochoanal polyps are benign lesions arising from the maxillary sinus mucosa. The most common patient complaint is unilateral nasal obstruction. Nasal endoscopy and computed tomography are the gold standard modalities for diagnosis. Treatment is surgical. We report the case of a 19-year-old female suffering from a huge antrochoanal polyp who went to hospital following a choking episode. While being prepared for surgery, she vomited, and the polyp was expelled from her mouth. Right maxillary sinus antrostomy was done to remove the polyp base to avoid recurrence.

Significance of nasal septal deviation among patients with antrochoanal polyp

OBJECTIVE

This study aimed to examine the association between nasal septal deviation and antrochoanal polyp.

METHODS

This was a retrospective review of medical records and imaging of patients who underwent endoscopic sino-nasal surgery for antrochoanal polyp.

RESULTS

Forty-eight patients operated on for antrochoanal polyp between 2009 and 2019 were eligible for the study. The median age was 32 years, and 52.1 per cent were male. Antrochoanal polyp was diagnosed equally in the right and left nasal cavities. Septal deviation was present in 77 per cent of such cases. In 44 per cent of septal deviation cases, the antrochoanal polyp was ipsilateral to the deviation, which was not statistically significant. The type of deviation according to the Mladina classification was not correlated with the laterality of septal deviation and antrochoanal polyp.

CONCLUSION

The laterality of the septal deviation was not found to be correlated with that of the antrochoanal polyp. Therefore, performing routine septoplasty during antrochoanal polyp surgery is unnecessary unless the deviation interferes with the complete extraction of the polyp.

Pheno-Endotyping Antrochoanal Nasal Polyposis

PURPOSE OF REVIEW

Antrochoanal polyps (ACPs) are benign polypoid lesions arising from the inner wall of the maxillary sinus and extending into the choana. Although the diagnosis and treatment strategies of ACP have changed since this entity was first described, the underlying pathogenic mechanism of APC is poorly understood. This article reviews the current knowledge of the etiology, inflammatory parameters, and microscopic findings of ACP.

RECENT FINDINGS

The inflammatory pattern of ACP appears to center around a neutrophilic inflammation T1-dominant endotype. Apart from the inflammatory component of ACP, at the microscopic level, the presence of tissue remodeling, mostly fibrin deposition and edema, and cysts in the epithelium and lamina propria has been described. Although the origin of this T1-dominant endotype immune response of ACPs is not entirely clear, it could be related to a lymphatic obstruction mechanism. This review serves to define a phenotype of ACP with potential endotypes based on the characteristics of the inflammatory parameters, microscopic findings, and hypotheses about the pathogenesis of ACP.

The effect of anatomic variations and maxillary sinus volume in antrochoanal polyp formation

PURPOSE

The antrochoanal polyp (ACP), otherwise known as the Killain polyp, is a benign lesion that originates from maxillary sinus mucosa, extending from the accessory ostium towards the middle meatus, and later tends to protrude posteriorly towards the choana and nasopharynx. Many studies have emphasized that its etiopathogenesis is unclear. Research suggests that chronic sinusitis and allergic rhinitis are factors that play an important role in the formation of ACP, as well as anatomical variations. In this study, we aimed to evaluate the effect of anatomical variations and maxillary sinus volume in patients diagnosed with anthrochoanal polyp.

METHODS

Paranasal sinus computed tomography (PNS CT) images of patients with unilateral ACP patients were examined. The non-ACP sides of the patients comprised the control group. Nasal septal deviation, agger nasi cells, concha bullosa, paradoxical middle turbinate, hyperpneumotized ethmoid bulla, uncinate pathology (medialized or pneumatized uncinate), haller cell, accessory ostium, maxillary sinus retention cyst and maxillary sinus volumes were evaluated.

RESULTS

The study included a total of 54 patients (33 females, 21 males). Mean patient age was 22.92 ± 13.95 (range 6-56) years. Mean maxillary sinus volume was 17.88 ± 5.16 mm³ for the ACP sides and 16.37 ± 4.55 mm³ for the non-ACP sides. Maxillary sinus volume was significantly larger in the ACP side (p = 0.000). Concha bullosa was observed on the ACP side in 23 patients (42.6%) and in the non-ACP side in 21 patients (38.9%). Agger nasi cells were observed in the ACP side in 47 patients (87.0%) and in the non-ACP side in 42 patients (77.7%). Hyperpneumatized ethmoid bulla was observed in the ACP side in 14 patients (25.9%) and in the non-ACP side in 12 patients (22.2%). Haller cells were observed in the ACP side in seven patients (12.96%) and in the non-ACP side in ten patients (18.51%).

CONCLUSION

Disrupted airflow of the well-developed maxillary sinus cavity due to anatomical variations seems to be an effective factor in the formation of ACP.