¹Associate Professor, ²Assistant Professor, Department of Radiology, Vilasrao Deshmukh Government Institute of Medical Sciences, Latur, Maharashtra, INDIA.

Email: mahesh2kadam@gmail.com

RESULTS

Table 1: Distribution according to age

Table 2: Distribution according to gender

Table 3: Distribution according to anatomical variation number

Table 4: Distribution according to CT detected anatomical variation

Table 5: Regions involved and anatomical variations associated with it

Graph 1: Anatomical variation and its distribution according to gender; Graph 2: CT scan detected sinuses involved

DISCUSSION

The paranasal sinus region is subject to a large variety of lesions. Congenital anomalies and normal anatomical variations in this region are important as they may have pathological consequence or may be the source of difficulty/ complication during surgery. Stumberger et al. proposed that stenosis of the osteomeatal complex, from either the anatomical configuration or hypertrophied mucosa, can cause obstruction and stagnation of secretions that may become infected or perpetuate infection. Concha bullosa (pneumatised middle turbinate) has been implicated as a possible aetiological factor in the causation of recurrent chronic sinusitis. It is due to its negative influence on PNS ventilation and mucociliary clearance in the middle meatus region. The presence of a concha bullosa has ranged between 4% and 80% in different studies; our data gave 50.8% which is less compared to 53.6% observed by Bolger and more compared to incidence reported by Zinreich S et al.9 (36%), Dua K et al. (16%) and Peres et al. (24.5%). Such a wide range of incidence is due to the criteria of pneumatisation adopted. The middle turbinate may be paradoxically curved i.e. bent in the reverse direction. This may lead to impingement of the middle meatus and thus to sinusitis .In our study it was found in 9 patients (14.3%) – 6 unilateral, 3 bilateral.The incidence of 14.3% in our study is close to the 58.10 % incidence described by Peres et al.Zinreich S et al.9 first observed that the uncinate process may be curved or bent. It can impair sinus ventilation especially in the anterior ethmoid, frontal recess and Infundibulum regions. In the present study curved uncinate was found in 5 patients unilaterally ( 8%) and 4 patient bilaterally (6.3%), a total of 14.3%. It is slightly higher than that of 2.5% reported by Bolger et al. A markedly medially bent or pneumatized uncinate process with a corresponding area of extensive contact with the middle turbinate can cause sinusitis. Combination of some anatomic variations such as uncinate bulla and Haller's cell may increase pathogenic effect compared to the effect of single variant. We encountered uncinate bulla (Fig.9) in 3 (4.8%) patients, 2 unilateral and 1 bilateral. This is consistence with 5% reported by Mecit et al. and more compared to Zinreich S et al.9 (0.4%) and Bolger et al.60 (2.5%). Haller's cells are ethmoid air cells that project beyond the limits of the ethmoid labyrinth into the maxillary sinus. They are considered as ethmoid cells that grow into the floor of orbit and may narrow the adjacent ostium (. The incidence of Haller's cells in our study was 2 (3.2%) – 1 unilateral and 1 bilateral. Kenedy and Zinreich et al.9 reported incidence of 10% which is more than our incidence. It is also more than that reported by Bolger et al.60 (45.9%) and Asruddin et al.87 (28%). Agger nasi cells lie just anterior to the anterosuperior attachment of the middle turbinate and frontal recess. These can invade the lacrimal bone or the ascending process of maxilla. These cells were present in 37 patients (58.7%) in our study. The incidence is less as compared to 98.5% by Bolger et al.. It is more than observed by by Dua K et al.84 (40%). In anatomic dissections, Messerklinger encountered the Agger nasi cells in 10-15% of the specimens, Davis in 65% of specimens and Mosher in 40% of specimens.  Onodi cells are posterior ethmoid cells that extend posteriorly, laterally and sometimes superior to sphenoid sinus, lying medial to the optic nerve. The chances of perioperative injury to optic nerve are increased when the bony canal of the nerve is lying dehiscent. Most authors have found an incidence of 8–14%, 10.9% by Pere and 11% by Bogler. It was found unilaterally in 7 patients in our study (11.1%). The clinical significance of anatomical variants of the nasal sinus region is  controversial. Most CT anatomical studies of the sinus region have been made in patients suspected of a clinical syndrome suggesting inflammatory sinus pathology. Zinreich S et al.9 found that 62% of his patients presented at least one anatomic variant, against 11% in the normal control group. These findings seem to suggest a positive correlation between anatomical variants and the appearance of inflammatory sinus pathology. However, Bolger et al. in a series of 202 patients studied by CT, observed 131 anatomical variants, but found the incidence in patients with sinus pathology was similar to that in persons studied for other reasons. Bolger et al.60 and Stammberger et al.6 and Wolf et al.88 detected the presence of anatomical variants both in patients studied for sinus problems and in those studied for other reasons. They concluded that the simple presence of variants does not mean a predisposition to sinus pathology, except when other associated factors are present. This opinion is not shared by Yousem et al.89, who claimed that the anatomical variants may be predisposing factors, depending on their size. In our study, 25 patients were detected with anatomical variations out of 37 who had mucosal changes. So, the prevalence was 67.6%. In our study, 18 patients were detected with anatomical variations out of 26 in whom mucosal changes were absent. So, the prevalence was 69.2% From this observation our study also reveals that the presence of anatomical variants does not mean a predisposition to sinus pathology. However, it is important for surgeon to be aware of variations that may predispose patients to increased risk of intraoperative complications. The radiologist must pay close attention to anatomical variants in the preoperative evaluation and help avoid possible complications and improve success of management strategies.

       Figure 1                                                     Figure 2                                               Figure 3

       Figure 4                                  Figure 5                                 Figure 6                                                           Figure 7

Figure 1: CT scan PNS coronal section showing bilateral middle concha bullosa- right larger than left; Figure 2: CT scan PNS coronal section showing Bilateral maxillary and right anterior ethmoidal sinusitis, paradoxical curvature of middle turbinate on the left side (arrow) and DNS to the right side (curved arrow); Figure 3: CT scan PNS coronal section showing pneumatized uncinate process on the left side (arrow); Figure 4: CT scan PNS coronal section showing prominent Agger Nasi cells on the left side (arrow); Figure 5: CT scan PNS coronal section showing large Haller’s cell on the left side (arrow); Figure 6: Prominent bulla ethmoidalis and concha bullosa; Figure 7: Concha bullosa and pneumatized uncinate process

CONCLUSION

According to the results, nasal septal deviation was the most common anatomic variation. Haller cell and pneumatised septum are the rarest ones noted in our study. Also, there was a strong correlation between the unilateral Concha bullosa and contra lateral septal deviation, which was evident based on the studies.

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