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[ 97 ] THE ARTERIES AND VEINS OF THE LUNGS I. RIGHT UPPER LOBE By A. B. APPLETON, Department of Anatomy, St Thomas's Hospital Medical School The arrangement of the larger vessels within the scribed by Lucien & Weber has a different appear- lungs was described by Ewart (1888) and subse- ance, but its relation- to that of Glass has been quently, without knowledge of his work, by Melni- elucidated by Appleton (1944). koff (1924). Herrnheiser & Kubat (1936) later gave The observations of Ewart showed that the vas- a description which took into account the work of cular pattern within the lung is closely related to Ewart and Melnikoff and in addition that of Back- that of the bronchi; this conclusion implies a rela- mann (1924). The veins were described by Adachi tionship to the bronchopulmonary segments. Ewart (1933) for Japanese subjects. These accounts, though found that the branches of the pulmonary artery detailed, lack precision as to the relations of vessels follow the brohchi while the veins are by contrast to those large subdivisions of the lung now known spaced out between them. According to Miller, 1937, as bronchopulmonary segments to which Kramer & again, the collecting veins from the pulmonary unit Glass (1932). first directed attention. Lucien & or 'lobule' (ventilated by a terminal bronchiole) are Weber (1936) have recognized similar subdivisions situated peripherally to the lobule while branches of which they have grouped as 'territories of ventila- the pulmonary artery follow respiratory bronchioles tion'. to their final distribution. The consequence of this The pattern of the bronchopulmonary segments vascular pattern would be that the artery to a depends on the mode of branching of the bronchial bronchopulmonary segment would be distributed tree. Each segment is ventilated by a single bron- within the segment along with the branches of the chus which ventilates no other segment. The term ventilating bronchus, while the veins would lie in bronchopulmonary segment has been restricted the intervals between segments. Appleton (1944) arbitrarily to those relatively large portions of lung has indeed observed that the main veins run on the which are ventilated by bronchi that have orifices periphery of segments, either between adjoining into one of the lobar bronchi. These segments can ones or on the pleural surfaces of the lungs. be isolated from their neighbours by dissection with The relation of vessels to segments is not, how- varying degrees of ease, since there are intervening ever, so clearly defined as these accounts suggest. planes of connective tissue, which will be here dis- Hovelacque, Monod & Evrard (1937) and Appleton tinguished as the 'intersegmental planes'. Tribu- (1944) have pointed out that although arteries in taries of the pulmonary veins lie in these planes and general accompany the bronchi very closely yet in receive veins from the contiguous segments (Apple- the region of the hilum the arrangement of the ton, 1944). Each segment may be further divided arteries does not entirely reproduce the pattern of into zones which are ventilated by the branches of the bronchial tree. Narath (1901) showed that the the segmental bronchus (Foster Carter, 1942; same artery sometimes provides branches which are Appleton, 1944). These will be termed 'subseg- distributed with bronchi belonging to different parts ments'. The subsegments like the segments are of the bronchial tree, and both he and Melnikoff separated by connective tissue planes, the sub- (1924) found that branches of the same bronchus segmental planes. are sometimes supplied by arteries with different It is generally accepted that supernumerary origins from the pulmonary artery. The work of fissures, clefts or notches tend to develop on the site these authors thus showed some lack of corre- of any of the intersegmental planes (Testut, 1930); spondence between the arterial and the bronchial they are also found sometimes on the sites of sub- pattern. segmental planes (Appleton, 1944). The right and Melnikoff (1924) recognized variability in the left lungs exhibit similar patterns of bronchopul- manner of origin of the larger vessels in the hilum, monary segments; the fissural pattern and the distinguishing 'magistral' and 'zertreut' types. division into lobes is a superficial feature which is Alternative names for these types have been offered subject to individual variation without essential by Herrnheiser & Kubat, who distinguish them as difference in the segmental pattern (Appleton, 1944). tree-like (dendroid) and bush-like (thamnoid) types. There is, however, individual variation in the rela- The accounts of these authors largely ignored the tive size of a given segment (Brock, 1942). pattern of the bronchial tree. Melnikoff felt unable The pattern of the bronchopulmonary segments to adoptthe well-known descriptions of the bronchial described by Kramer & Glass, and by Glass (1934), tree given by Aeby (1880) and Narath, who recog- has been accepted with modifications by subsequent nized a series of dorsal and ventral branches. He be- British and American authors. The pattern de- lieved it wouldbe more correct to describe the vessels, Anatomy 79 7 98 A. B. APPLETON especially the arteries, according to the lung regions by later investigators, viz. that of subsegment or they supply, in spite of differences of origin and subsegments in one of the three larger zones (Apple- calibre. Herrnheiser & Kubat have adopted a ton, 1944). Thus the posterior and anterior segments similar attitude (p. 601), inasmuch as various ar- of Kramer & Glass are not entirely equivalent to teries supplying the posterior part of the upper lobe the pectoral and subapical segments of Brock, but are identified by the same name 'A. axillaris' though include portions only of these segments; the 're- their origins are widely different. maining portions being included under the heading The account of the vascular arrangements of the 'axillary'. segments in this paper will be given with reference The right upper lobe is divided, then, into three to the descriptions of the segmental pattern given bronchopulmonary segments which will be termed by Foster Carter (1942) and Appleton (1944). The pectoral, apical and posterior (cf. Fig. 13). These arterial supply and venous drainage of the segments names have been selected from the various names and subsegments are examined with special refer- that have been employed by different authors on the ence to recognition of the larger vessels with which grounds of convenience, suitability and distinctive they are connected in the hilum of the lung, as seen character (Appleton, 1944). They have proved by approach to the lung root, anteriorly, posteriorly adaptable to the naming of the arteries, veins, and or through the interlobar fissures. intersegmental planes in such a way as to indicate the relations of the vessels to bronchopulmonary MATERIAL AND METHODS segments. The segments are ventilated by bronchi which arise from the upper lobe bronchus and bear The present description of the vascular pattern and the same names as the segments; they are separated its variations is based on a study of fifty adult right by intersegmental planes which will be distinguished lungs. Of these, forty-five had been preserved as the 'apicopectoral', 'apicoposterior' and 'pec- in situ in cadavera prepared for the dissecting room. toroposterior' planes. The term 'eparterial' in re- The remaining five were prepared from fresh post- ference to the right upper lobe bronchus is rejected mortem specimens. for reasons which have been stated by a succession They were examined by dissection from the of authors (Ewart, Narath, Brock). mediastinal, costal and interlobar surfaces, supple- mented in certain instances by horizontal slicing of planes (Figs. 1, 2, 6, 1M and 20) the upper lobe. In twenty specimens injections of Intersegmental coloured gelatine were made into the arteries and The apicopectoral plane separates the apical and veins; in the five fresh specimens these provided a pectoral segments. It abuts on the mediastinal sur- complete injection of the vessels, in the remainder face along a line that curves with an anterior con- only a partial one of the larger vessels. vexity upwards from the root of the lung to reach the anterior margin, at or close to the subelavian THE UPPER LOBE OF THE RIGHT LUNG groove. From this line the plane extends postero- laterally within the upper lobe, and the pectoral The pattern of the bronchi and bronchopulmonary segment thus extends farther back on the costal segments of the upper lobe will be reviewed briefly, than on the mediastinal surface. without attempt at a full account of the variations The apicoposterior plane meets the mediastinal which have been summarized in a previous paper surface along an oblique line that passes upwards (Appleton, 1944). There has been much variation in from the root of the lung to the margin just behind the terminology employed by different authors as the apex. This plane is inclined posterolaterally shown below. towards the costal surface. Bronchi and bronchopulmonary segments. Names previously employed Ewart Pectoral Apical Axillary Nelson Pectoral .Apical Axillary Hasse Anterior Posterior Kramer & GlasE Anterior Apical Posterior Axillary Lucien & WebeiLr Upper ventral Apical Upper dorsal External Parabronchial Neil, Gilmour & Gwynne Anterior Apical Paravertebral Axillary Barrett Pectoral Apical Posterior Axillary Peirce & Stocking Ventral Apical Dorsal Foster Carter Anterolateral Apical

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