Practical pathology

by Aldred Scott Warthin

Fig. [35].—Sagittal section of left middle ear, inner half. op, mouth of Eustachian tube; te, Eustachian tube; tp, musc. tensor tymp.; p, promontory; st, stapes; sp, musc. staped; f, facial nerve; an, mastoid antrum; ww, mastoid cells; ot, ost. tymp. tubæ; u, lower wall of tympanic cavity. (After Politzer.)

Other methods of examining the ear are shown in Fig. [32]. The tympanic cavity and labyrinth may be removed intact by cutting with a chisel having a cutting edge 3 cm. broad, in the lines 1, 2, 3, 4, 5, as shown in Fig. [32]. The cut 1 is made with the chisel held nearly horizontal and parallel with the base of the skull. Cuts 2, 3, 4 and 5 are made vertically. Great care must be taken not to splinter the bone. A small chisel can be used to connect the ends of the cuts. Soft parts are cut away with the chisel. An elevator is then introduced into cuts 1 and 2 and the part lifted out by cutting the remaining soft parts and the articulation of the lower jaw. The portion removed contains the inner section of the external auditory canal, tympanic cavity, ear-drum, a portion of the mastoid cells, the entire labyrinth, auditory and facial nerves.

Politzer’s method of removing the auditory apparatus in connection with the nasopharynx and the Eustachian tubes is also shown in Fig. [32] by the lines a, b, c, d, e. Two drill-holes are made in the floor of the anterior fossa at a, 1 cm. to the right and to the left of the crista galli, extending vertically through the nasal cavity to the under surface of the hard palate. A fine key-hole saw is then introduced through the right drill-hole, and the base of the skull is then sawed in the lines ab, bc, cd and de as indicated in Fig. [32]. Symmetrical cuts are then made on the left side following the same lines and the two drill-holes connected by a transverse saw-cut. Any remaining bony connections are then cut with a wide chisel. In order to cut the bony bridges in the region of the nasopharynx it may be necessary anteriorly to use the Hey-saw through the mouth-cavity as well as from the cranial side. To facilitate the removal of the loosened portion two parallel saw-cuts are made in the occipital bone 3 cm. to the left and right of the median line, extending nearly to the posterior edge of the foramen magnum and connected below by a slightly rounded cut as shown in Fig. [32]. A long-armed chisel can now be used conveniently through the opening thus made, for horizontal manipulations upon the base of the skull, while the loosened portion of the base is lifted with the bone forceps or nippers set in the posterior saw-cut e and the sella turcica. As the bone is raised the posterior and lateral pharyngeal walls are cut with the cartilage-knife, the posterior wall of the capsule of the maxillary articulation on both sides severed, the jaw disarticulated, and all muscular and membranous connections cut, until the preparation is completely freed. The auditory apparatus and the Eustachian tubes can now be examined by any one of the methods given above.

7. Examination of Nose and Neighboring Cavities. Of all the methods advised for the examination of the nasal cavities the method of Harke (Fig. [32]) is the easiest and gives the best views of the nasal tract. After the brain has been removed the scalp incision is carried downward to the middle of the neck on both sides, following the anterior edge of the trapezius, as for the removal of the temporal bone. The anterior flap is then carried forward as far as the bridge of the nose and the edges of the orbits, and the flap pulled down over the face. The posterior flap is carried back as far as the upper cervical vertebræ, removing the muscles with the scalp. The head of the cadaver is now raised and firmly held by an assistant or clamped in a head-holder; and with the large meat-saw the occipital bone is sawed through in the median line, cutting first the squama and then the clivus. The saw is then set anteriorly into the frontal bone, to the left or right of the septum, in order not to injure the septum narium. (Fig. [32].) The sawing then proceeds through the sella turcica, body of the sphenoid, ethmoid and frontal bones until the base of the skull is divided into halves. The cartilage-knife is then introduced through the foramen magnum and the basal ligaments cut. The right and left sides of the skull posteriorly are then taken in the two hands and with a quick, powerful tug forced outward until the nasal bones, hard palate and alveolar processes break apart. The two halves of the base of the skull then open like a book, turning on an axis, running through the inferior maxillary articulation and the occipito-atloid ligaments. If there is too great resistance in the region of the foramen magnum, the anterior and posterior arches of the atlas may be cut with a chisel. The sphenoidal sinus, septum narium, frontal sinus and the nasal cavity on one side of the septum with the nasopharynx are thus exposed, and their walls and contents may now be examined. Material for bacteriologic examination should be secured before further cutting is done. The septum may then be removed with forceps and scissors, the nasal cavity on the other side examined, the nasopharynx inspected, and the antrums opened with small bone-forceps. After the examination is complete the halves of the base are brought together and fastened with copper wire anteriorly and posteriorly, taking care that the anterior wire will not be visible through the skin of the forehead.

8. Examination of Face. When the anterior flap of the scalp is carried down to the edge of the orbits and half-way across the lower jaw as advised above for the removal of the temporal bone, the parotid region may be examined. The upper and lower maxillary bones are best examined after the removal of the neck-organs. A transverse incision is made in the skin of the neck low enough to be concealed by the clothing, and connecting with the longitudinal scalp-incisions. The facial flap is then dissected upward with great care as far as the infraorbital edges, exposing the maxillary bones, from which the soft parts must be so carefully removed that restoration of the face can be made. For the examination of the anterior nasal-cavities the upper lip must be separated from the bones.

II. POINTS TO BE NOTED IN SECTION OF HEAD.

1. Scalp. Note wounds, hemorrhages, inflammations, scars, parasites, neoplasms, number and location of bleeding-points on section, color of different portions, adhesions to periosteum or cranial bones, etc. Most common pathologic conditions are wounds, hemorrhages, wens, lipoma, squamous-celled carcinoma, syphilis, tuberculosis, favus, pediculi, tricophytia, angioma and round- and spindle-celled sarcomata. The temporal muscles should be examined for hemorrhages, œdema, purulent inflammations and trichinæ. The postmortem hypostasis of the back of the head should not be regarded as pathologic.

2. Periosteum. Subperiosteal hemorrhages, purulent infiltrations, adhesions, indurations, chronic inflammation with new-formation of bone, and neoplasms are the most common pathologic conditions.

3. Skull-Cap. The measurements (circumference, 49-65 cms.; long. diam., 18 cms.; trans. diam., 13-15 cms.), form, asymmetry, character of surface (normally smooth and moist), color of cranial bones, character of sutures and fontanels (easily traced?), supernumerary sutures and bones, consistence (softened in craniotabes, purulent inflammations, syphilis, neoplasm), new-formations of bone, perforations (syphilis, neoplasms, Pacchionian granulations, purulent inflammation), elevations, depressions, fractures, areas of erosion or absorption, thickenings of external surface (crater-like due to organized cephalhæmatoma, chronic periostitis, neoplasm or gumma), radiating scars or indurations (syphilis), red, soft, spongy thickenings (rachitis). The temporal and frontal regions are most frequently the seat of syphilitic (corona veneris) and rachitic changes (frontal and temporal bosses, square forehead, etc.) Note ease or difficulty in sawing, relation of external table, diploë and inner table, measure thickest and thinnest portions, character and amount of diploë, weight of skull-cap (heavy in sclerosis, light in atrophy), dural adhesions, examine by transmitted light (color, blood-content, presence of pus in diploë may be shown by greenish or yellow color), smooth or rough inner table, erosions (rough, more or less reddened), grooves of meningeal vessels, Pacchionian erosions, hyperostosis, exostosis, osteoma, osteophytes (not uncommon in pregnant women, also in hydrocephalus, acromegaly), atrophy (old age, craniotabes, hydrocephalus), sclerosis (syphilis). In marked cachexias (cancer of stomach) the inner table often shows a high degree of erosion and atrophy.

4. Dura. Collections of pus may be found between skull-cap and dura in purulent inflammations of scalp or diploë. Rupture of middle meningeal artery or its branches, with or without fracture of the skull, gives rise to hemorrhagic extravasations in same location. Old hemorrhages may be partly organized. In young infants the dura is adherent to the skull-cap and cannot be separated. In youth and adult life it is adherent only along the longitudinal sinus and about the blood-vessels; in old age it becomes more adherent. Extent, location and strength of adhesions should be noted. The normal dura should be grayish-red, smooth, symmetrically stretched, so that a small fold only can be taken up by the fingers in the frontal region, and just translucent enough to show the outlines of the convolutions and the pial vessels. An increased tension is caused by exudates, tumor, abscess, hydrocephalus, hemorrhage, congestion, œdema, etc. Diminished tension occurs in atrophy of the brain, especially marked in the frontal region, where the dura may be wrinkled and loose. Perforations of the dura by Pacchionian bodies are very common along the longitudinal sinus in late life, and should not be regarded as pathologic. Small osteomata are not uncommon in the same place and in the falx; they may be very numerous in acromegaly, late syphilis and cachectic conditions. Changes in the color of the surface of the dura may be due to hemorrhage, purulent or syphilitic inflammation, old thickenings, etc. Thickenings are more easily seen from the inside surface of the dura; they appear as hard, tendon-like, opaque areas. The normal inner surface is smooth, grayish and moist-shining. In pachymeningitis it may be dry, dull, roughened, and covered with blood, pus or fibrin. The most frequent pathologic condition on the inside of the dura is the organizing or encapsulated hemorrhage (pachymeningitis hæmorrhagica chronica, hæmatoma duræ), so common in chronic alcoholics. Miliary tubercles of the dura are common in meningeal tuberculosis. A gummatous pachymeningitis is not infrequent in late syphilis. Pachymeningitis fibrosa is also common in old syphilitics. Actinomycosis occurs in connection with actinomycotic encephalitis. The primary tumors of the dura are fibroma, osteoma, fibro-endothelial tumors (psammoma) and angiosarcoma, etc. Secondary carcinoma or sarcoma is rare.