Methods of Antrodrainage

Medical washing of the Antrum through drainage tube

It allowed us to determine the SAAA by the declination of a long axis of the EAC to a level of the skull.
The first operations of Antrodrainag in Republic Mali detected great range of SAAA variants (about 60 degrees), and the follow-up operations in Russia confirmed analogy of these variants. Many numbers of SAAA variants and enough quantity of the observations allowed us to make attempts to discovering some regularities of their appearance.

Materials and methods:

Caption:

Dynamics of the "surgical" angle of approach to the antrum in depending of the patients age

Individual SAAA was determined over the contrast radiogram with filling of the EAC by radiopaque substance. This radiograph was made into the direct frontal X-ray projection of the skull (Fig1). Fig1

Caption:

Schematic drawing of the surgical angle(SA) of approach to antrum on the contrast radiogram of the skull

Legends: E - Classical horizontal plane of the skull; ACB - The longitudinal axis of the EAC; AD - The horizontal plane of the skull; DAB - The SA of approach to the antrum.

Over such radiogram, the SAAA was sized up by the inclination of a longitudinal axis of the EAC to a level of the skull. Particular attention was made to detecting of SAAA variants and to possible regularities of their objective manifestations. Equalization of the variational line was conducted by the method of the slipping medium for averaging-out of the received results. The discovered regularities of SAAA variants were processed statistically for support of their authenticity.

Results:

All patients were selected on 7 age groups (5-10, 11-20, 21-30, 31-40, 41-50, 51-60, 61-70 years) and over 100 patients were presented in the each group from the 2nd and till the 4th, but in the 7th group of elderly people was 17 (Tab.1) . More frequent the SAAA equalled to 18-20dg, while minimal "surgical angle" as minus 5(dg) was sized in 1,4 % and solely in the first four groups (Fig.1A), and maximal SAAA like plus 55dg was found out in the 2nd and the 3th groups together in 0,6 % (Fig.1B).  

Caption:

The diagram of dependence arithmetical mean of the surgical angle of approach to the antrum (SAAA)from the age into 500 patients with CSOM.

Legends: The SAAA is increased from 5 and until of 40 years age with by the next decrease particularly to 70 years age.

Average-statistical "surgical angle" was rising from 13,2dg in 5 age and up to 25,3dg in 40, with following lessening towards the 7th group till 18dg. Statistically reliable average arithmetic of SAAA in the 1th group was 13,2dg, in the 2nd group 13,2dg, in the 3th - 23,8dg and in the 4th group 25,3dg, that confirmed depending of increasing of the EAC slope to a level of the skull owing to the growing of patient's age. However, the purely surprise for us was to find the subsequent statistically valid decreasing of the SAAA after the age of 41, that was marked in the 5th, 6th and the 7th groups. The age's changes of the SAAA were statistically reliable, because p < 0,001 was in the 1th and up to the 6th group, while p < 0,005 was in the 7th group. The first statistical regularity of EAC declination changes to a level of the skull was detected in the form of increasing of the "surgical angle" from 5 age and up to 40 and the second regularity was as following decreasing of the "surgical angle" after the age of 41 (Fig. 2). Apparently, these age's variations of EAC declination could depend because of the growth of the age activity of the breast-clavicle-mastoid muscle, which one is reinforcing with development of the organism, but after the age 41 the activity of this muscle was gradually weakening, like all organism, with gradual dominance of destructive-sclerotic process of the skull-bones. Knowledge of these features of the mastoid cavity locations allows to perform the precise and harmless direct drilling through the mastoid into the antrum. That provides the real using of such minimally invasive and safe method antrotomy as Antrodrainag or "Slit-like" antro-atticotomy [3]. And also, it will help and allow to otosurgeons to avoid of dangerous complications during the performing of any other surgical interventions into the antrum through mastoid like antro-mastoidotomy, mastoidectomy, antro-atticotomy, radical operations on the middle ear and others.

Conclusions:

1. The most precise, minimal invasive and safety surgical penetration into the antrum through the mastoid can be warranted solely in a frontal plane of the skull, from Henle spine and lengthwise of the mastoid-scaly seam, which face is located under individual "surgical angle" to a level of the skull.

2. Individual "surgical angle" of approach to the antrum can be defined by the declination of the external auditory canal projection, which in a frontal plane of the skull is disposed in parallel with the mastoid-scaly seam.

3. More frequent "surgical angle" of the approach to the antrum equals to 18-20o, but there are also individual variants from minus 5dg and up to plus 55dg, and it is growing from the age of 5 and till 40 with the following particularly decreasing to 70 years.

References:

[4]Tarasov D.I., Fastovsky Y.A., Ulyanov Y.P., Itkin G.A: Age-related modifications of the surgical approach to the antrum. Vestnyc Otolaryngol. 1990; 62-5 (In Russian).