RU-2861542-C1 - METHOD FOR DETERMINING VOLUME OF OSTEOPLASTIC MATERIAL REQUIRED FOR OBLITERATION OF ANTROMASTOID CAVITY

RU2861542C1RU 2861542 C1RU2861542 C1RU 2861542C1RU-2861542-C1

Abstract

FIELD: medicine; radiology; otorhinolaryngology. SUBSTANCE: before surgery, determining the volume of the antromastoid cavity according to CT data of the temporal bone in two projections. To do this, drawing lines to determine the area of the antromastoid cavity S1 at the level of the projection of the greatest distance of the anterior and posterior limbs of the superior semicircular canal to the cortical layer of the mastoid process. Then, drawing lines to determine the area of the antromastoid cavity S2 at the level of the projection of the horizontal semicircular canal to the cortical layer of the mastoid process. After that, drawing lines to determine the area of the antromastoid cavity S3 at the level of the second genu of the facial nerve to the cortical layer of the mastoid process. Then, determining the height h of the coronary projection from the inner surface of the bony wall of the middle cranial fossa to the protruding part of the horizontal semicircular canal. Determining the volume V of the antromastoid cavity by the formula V = h/6 ´ (S1+4S2+S3), which corresponds to the volume of osteoplastic material required for the operation. EFFECT: determining the volume of osteoplastic material required for obliteration of the antromastoid cavity after antromastoidotomy at the preoperative stage. 1 cl, 13 dwg, 2 ex

Inventors

KRYUKOV ANDREJ IVANOVICH
Kunelskaya Natalya Leonidovna
ZELIKOVICH ELENA ISAAKOVNA
Mosejkina Liliya Alekseevna
Bavin Konstantin Sergeevich
Bragina Darya Andreevna

Dates

Publication Date: 20260505
Application Date: 20250731

Claims (1)

A method for determining the volume of osteoplastic material required for obliteration of the antromastoid cavity, which consists in the fact that before the operation, the volume of the antromastoid cavity is determined based on CT data of the temporal bone in two projections, for which lines are drawn to determine the area of the antromastoid cavity S1 at the level of the projection of the greatest distance of the anterior and posterior peduncle of the superior semicircular canal to the cortical layer of the mastoid process, then lines are drawn to determine the area of the antromastoid cavity S2 at the level of the projection of the horizontal semicircular canal to the cortical layer of the mastoid process, after this, lines are drawn to determine the area of the antromastoid cavity S3 at the level of the second knee of the facial nerve to the cortical layer of the mastoid process, then the height h of the coronal projection from the inner surface of the bone wall of the middle cranial fossa to the protruding part of the horizontal semicircular canal is determined and the volume of the antromastoid cavity V is determined by the formula V = h/6 × (S1+4S2+S3), which corresponds to the volume of osteoplastic material required for the operation.

Description

The invention relates to the field of medicine, namely to the radiation examination of computed tomography (CT) of the temporal bones, and can be used to calculate the volume of the antromastoid cavity (AMP) and the amount of osteoplastic material required for its obliteration, based on CT data at the preoperative stage. Chronic suppurative otitis media (CSOM) with cholesteatoma is a condition encountered in both outpatient and inpatient otolaryngology settings. Despite advances in medicine and pharmacology, its prevalence averages 23.9 cases per 100,000 population [1]. Surgical treatment and rehabilitation of these patients remains a pressing issue in modern otology. The basis of surgical treatment of chronic otitis media with cholesteatoma is the implementation of the sanitizing stage of the operation followed by a one-stage total reconstruction of the outer and middle ear, pursuing their return to the anatomical and functional norm [2, 3]. The mastoid process (MP), formed by the removal of pathological tissues from the mastoid process (MP) and integrated with the tympanic cavity, has an irregular cone-shaped form. Its obliteration is most often performed using safe autologous bone chips, which have a low cholesteatoma recurrence rate (recurrent - 10-12%, residual - 3-5%) [4]. In cases where anatomical features or repeated surgical interventions do not allow for obtaining a sufficient volume of autologous tissue for mastoidectomy, osteoplastic implant material with high osseointegration is used, which, similar to autologous tissue, is characterized by good biocompatibility [5, 6, 7]. When planning surgical treatment, it is important to consider the extent of middle ear inflammation and cholesteatoma, as well as the volume of the existing antromastoid cavity following previous debridement procedures. Knowing the approximate volume of the proposed or existing trephine cavity (TC) helps the surgeon choose the method of obliteration and calculate the amount of osteoplastic material to the nearest milligram. Therefore, determining the anatomical dimensions and extent of the proposed surgical intervention preoperatively allows for accurate planning of the required amount of osteoplastic material, which positively impacts the financial aspect of the procedure. There are works in the literature on the methods of determining the volume of the antromastoid cavity with chronic gastroesophageal reflux. Practicing surgeons limit themselves to the terms "small" and "large" volume. Gusakova A.A. in her dissertation determined the volume of the antromastoid cavity based on impedance data and divided it into small (less than 2.1 cm 3 ) and large volume (from 2.1 to 4.5 cm 3 ) [8]. Ognetov S.Yu. et al. calculated the volume of the antromastoid cavity intraoperatively, based on the amount of saline solution remaining in the syringe after filling the cavity [9]. In the work of Kokorkin D.N., after performing the sanitizing stage of the operation, the volume of the postoperative cavity was determined by infusing fluid. The cavity volume was divided into small - less than 2.0 ml, medium - 3-4 ml and large - more than 4.0 ml [10]. Varosyan Ya.G. determined the volume of the antromastoid cavity also intraoperatively, upon completion of the sanitizing stage of the operation, using a cast of sterile bone wax placed in the cavity [11]. Foreign research studies described the size of the air cell system planimetrically using lateral radiographs depending on the patient's age [12]. However, this method is currently not used due to the widespread use of CT of the temporal bone. Currently, high-resolution CT is widely used for the diagnosis of inflammatory diseases of the middle ear, in particular, chronic otitis media, as well as for the assessment of the middle ear condition after mastoidectomy and is a standard examination for preoperative visualization of the temporal bone. [13]. A rectangular (Cartesian) coordinate system, representing two mutually perpendicular axes X and Y, intersecting at one point O, on the basis of which integral methods of computed tomography are carried out, made it possible to solve geometric problems on a three-dimensional image [14]. All the programs used, including RadiAnt DICOM Viewer, are equipped with the function of automatic measurement of the length or area of the image in various planes when specifying Cartesian coordinates (node). Study of CT images of the temporal bone in chronic tympanic membrane inflammation allows to determine the degree of pneumatization of bone tissue, including the tympanic cavity, the spread of pathological substrate, to identify or exclude dislocation and destructive changes of the auditory ossicles and the walls of the middle ear cavities, as well as intracranial complications [15]. Michio Isono developed a method for assessing the volume of air cells in the middle ear of a healthy ear using digital processing of CT slices by isolating only the air cells and calculating