Importance of Keros Classification in Surgery

Abstract

Objective:The relationship between the cribriform plate and the uncinate process may be elaborated with the help of the Keros classification. The observations were analysed using high-resolution computed tomography (HRCT). Additionally, the relationship between the superior attachment of the uncinate process, the existence of concha bullosa, and the different types of ethmoid roofs were examined. Methods: Five-hundred and sixteen subjects complaining of sinonasal disorders between 2015 and 2016 were enrolled retrospectively at the Okmeydani Training and Research Hospital, Department of Otolaryngology. HRCT scans of 1-mm sections were obtained. Keros classification was used for the measurement of the depth of the olfactory fossa as follows: Keros I: 1-3 mm, Keros II: 3-7 mm, and Keros III: 7-16 mm. Results: Fifty-one point nine percentage of cases were of Keros type II, 27.7% of type III, and 20.3% of type I. In 82.4% of the reported cases, the uncinate process was attached to the lamina papyraceae, in 11% of the cases it was attached to the middle nasal turbinate, and in 6.4% cases to the skull base. A concha bullosa was observed in the right nasal cavity in 13.8% of the cases, in the left nasal cavity in 11% of the cases, and bilaterally in 16.3% of the cases. Variances observed in the Keros types were not statistically significant with respect to sex (p>0.05). Concha bullosa was significantly more frequently seen in females (53.1%) relative to males (p=0.001). Conclusion: Endoscopic sinus surgery (ESS) is the primary mode of treatment for chronic sinus diseases. In this procedure, a proper assessment of the vital structures is very important to avoid further complications. In the present study, it has been suggested that determining the depth of the ethmoid roof is necessary to avoid injuring the bony lamella, which can lead to cerebrospinal fluid rhinorrhea.

Computed tomography assessment of the ethmoid roof based on Keros classification in Iraqi patients undergoing functional endoscopic sinus surgery

“…Similar findings to Keros's study have been reported in in various countries such as South Korea [15], Turkey [18], Turkey [19], Turkey [20], Turkey [21], Turkey [22] , Thailand [23], Brazil [10], Germany [24], Egypt [25], Pakistan [26], Poland [27], Saudi Arabia [28], India [29], India [30] , and Iran [31]. Unlike to Keros study [9], and similar studies [10,15,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] our findings showed that Type I is the most common type (71.0%), followed by Type II (27.4%) and the Type III (1.6%) of the cases, respectively. However, our findings inline to results reported in studies from Philippine [16], USA [32], UK [33], Nepal [34], Malaysia [35], and Egypt [36] which confirms that the Keros type I is the most common.…”

Radiological Evaluation of Olfactory Fossa with Cone-Beam Computed Tomography

“…In our study, the most common were Keros type II (71.9%), followed by Keros type I (17.8%), Keros type III (10.3%). While a few studies reported the most common Keros type I [1,2,7,20,21], most studies were the most common type II [3][4][5]8,[13][14][15][17][18][19][22][23][24][25][26][27][28], consistent with our study. The distributions according to the Keros classification in the studies conducted in the Turkish population are presented in Table 6.…”

The Importance of Cribriform-Lamella Angle in Endoscopic Sinus Surgery

“…Chronic Rhino Sinusitis (CRS) is a clinical syndrome characterized by persistent symptomatic inflammation of the mucosa of nose and paranasal sinuses. Computed Tomography scan is the radiological investigation of choice in CRS [3]. It is often advised as a preoperative guide to assess the disease extension and anatomic variations.…”

“…In endoscopic sinus surgery, roof of the nasal cavity is considered to be the area of importance and a thorough knowledge of the intricate anatomy and variations is required to prevent complications. Perhaps, the most perplexing complication is breach of skull base secondary to an unrecognized low lying anterior cranial fossa [3][4][5][6].…”

“…Complications related to a low-lying skull base like CSF leak, brain hemorrhage, loss of smell, pneumocephalus, brain injury and encephalocele have all been reported [4,12]. In literature, Keros II/I are more common followed by Keros III [3,11,[13][14][15][16][17]. The variations in literature regarding whether type II or I is common can be due to the methodology used by various authors in measuring the depth.…”