We have had abundant opportunity to observe early stages in the production of bronchiectasis and to study the much discussed pathogenesis of the condition.

The following figures show the predilection of bronchiectasis for the left lung and for the lower lobes: Bronchiectasis occurred 30 times in the left lung alone, 9 times in the right lung alone and 13 times in both lungs, the total being 52. Among 30 instances in which the lesion occurred only in the left lung, in 24 it was limited to the lower lobe, and in 15 of these 24 instances to the base of the lower lobe. Among 9 instances in which dilatation of bronchi occurred only in the right lung, it was limited to the lower lobe in 4 instances and to the base of the lower lobe in 2 of these 4 instances.

When the lesion is limited to the base of the lower lobes small bronchi with no recognizable cartilage in their wall are dilated to a diameter of from 3 to 6 cm. and are distended with thick mucopurulent fluid. The tenacious character of the bronchial contents and the action of gravity doubtless have a part in the production of the dilatation. In several instances dilatation of the bronchi was limited to the basal parts of both upper and lower lobes.

When bronchiectasis occurs throughout a whole lung, usually the left, or in both lungs, the lesion is more advanced and conspicuous (Fig. 26). There is diffuse dilatation of small and medium-sized bronchi. Dilated bronchi with deeply injected mucosa and filled with yellow mucopurulent fluid, are seen throughout the sectioned lung. A bronchus cut longitudinally may have a nearly uniform diameter of from 5 to 9 mm. for a distance of 5 or 6 cm., maintaining this diameter to within 1 cm. of the pleural surface, where normally only small bronchi occur.

More advanced bronchiectasis is represented by the occurrence of spherical bronchiectatic cavities, having a diameter from 1 to 2.5 cm. In some instances there have been two or three of these cavities but occasionally there may be many. Cylindrical dilatation of the bronchi usually occurs widely distributed in the lungs. In Autopsy 440 a small bronchus, cut longitudinally, was dilated to a diameter of 5 mm. for a distance of 5 cm. and terminated in a spherical cavity 2 cm. in diameter; there was another smaller spherical cavity nearby and dilated bronchi occurred elsewhere. In Autopsy 467, in the upper part of the lower lobe, two spherical cavities 1 and 1.5 cm. in diameter communicated with a bronchus of medium size.

Autopsies with bronchiectasis are listed in the order of the duration of illness to show the parallel increase in the severity of the lesion (Table LI). In 2 instances (Autopsies 244 and 314) bronchiectatic cavities surrounded by firm fibrous tissue have evidently existed before the onset of the fatal illness, which has lasted in one instance approximately four and in the other six days; these autopsies have been omitted from the table.

The table shows that bronchiectasis observed within twelve days after onset of illness with symptoms of influenza is moderately advanced and almost invariably limited to the left lower lobe and usually to the base of the lobe. Advanced dilatation, indicated by the formation of spherical or cylindrical cavities, occurs with increasing frequency as the duration of the respiratory disease increases.

Bronchiectasis has been almost invariably associated with purulent bronchitis. The dilated bronchi contain mucopurulent material and throughout the lungs the same condition is usually widespread. Among 137 instances of purulent bronchitis bronchiectasis consequent upon influenza has been present in 50.

Table LI
NO. OF AUTOPSYDURATION OF ILLNESS IN DAYSTYPE OF PNEUMONIALOCATION OF BRONCHIECTASISCHARACTER OF BRONCHIECTASISBACTERIA IN BRONCHUS
3945 ?BronchoRt. baseDilatation
3597 +Lobar and bronchoLt. lower lobeDilatation
3228Abscess (staph.)Lt. baseDilatation
3258Interst. suppurationLt. baseDilatationS. hem., B. inf., staph.
3528Lobar and bronchoLt. lower lobeAdvanced dilatation
4298 ?BronchoRt. baseDilatation
28810AbscessLt. baseDilatationS. hem., B. inf.
37410Lobar and bronchoRt. and lt. lungsAdvanced dilatation
37610AbscessLt. baseDilatationS. hem.
43711LobarRt. lower lobeAdvanced dilatation
48211BronchoLt. baseDilatationB. inf., Pneum. IV, S. hem.
48911Lobar and bronchoLt. lungDilatationB. inf., Pneum. IV.
28712Lobar and bronchoLt. lower lobeAdvanced dilatationPneum. IV., B. inf., staph.
28912BronchoLt. lower lobeAdvancedPneum. IV., B. inf. staph.
29512Interst. sup. and abscessRt. lungAdvanced dilatationS. hem., B. inf.
33612BronchoLt. baseDilatation
37512BronchoRt. and lt. basesDilatation
42212 ?Lobar and bronchoLt. baseDilatation
38113AbscessLt. baseSpherical
39113Lobar and bronchoLt. lungDilatation
40114 ?Lobar and bronchoRt. and lt. lungsSpherical
40214Chronic bronchoRt. lower lobeDilatation
41014 ?AbscessRt. upper lobeDilatation
33315Abscess (staph.)Lt. upper lobeDilatationS aur., B. inf. S. hem.
38915Interst. suppurationLt. lungAdvanced dilation
41215Lobar and bronchoLt. lower lobeCylindrical
39816BronchoRt. and lt. lungsAdvanced dilatation
42316BronchoLt. baseDilation
48816AbscessLt. lower lobeDilatationS. hem., Pneum. atyp. II.
31217BronchoRt. and lt. lungsDilatationS. hem., B. inf. staph.
37217BronchoRt. lungDilatation
385 C17Interst. suppurationLt. baseDilatation
44817BronchoLt. lungDilatation
46017AbscessLt. lower lobeSphericalS. hem., B. inf., staph.
29118BronchoLt. baseAdvanced dilatationB. inf., staph.
29618AbscessLt. baseDilatationS. hem., B. inf.,
38719AbscessRt. and lt. lungsAdvanced dilatationS. hem., B. inf., S. aur. Pneum. II.
42119Chronic bronchoRt. lungAdvanced dilatation
44019Chronic bronchoRt. and lt. lungsSphericalB. inf., S. aur.
41920BronchoRt. lungDilatationPneum. II, B. inf.
46320Chronic bronchoRt. and lt. lungsSphericalB. inf., staph., Pneum. IV
43123Chronic bronchoLt. baseDilatation
46823 ?Lobar and bronchoLt. lungDilatationS. aur., B. inf., S. vir.
46525 ?BronchoLt. baseDilatationS. hem., B. inf., staph., S. vir.
44527BronchoLt. lower lobeSphericalS. aur.
44927AbscessRt. and lt. lungsSphericalS. hem., B. coli.
37828AbscessLt. baseCylindricalS. hem., B. inf., Pneum. atyp. II.
47328Chronic bronchoLt. lungAdvanced dilatationB. inf., S. vir., staph., M. catarr.
42529Abscess (staph.)Rt. and lt. lungsCylindrical
46730AbscessRt. lower lobeSphericalS. hem., B. inf.
47237Chronic bronchoRt. and lt. lungsAdvanced dilatationB. coli
48755AbscessRt. and lt. lungsCylindricalB. inf. S. hem.

The bacteriology of autopsies with bronchiectasis is shown in Table LII.