Talk:Paper - Persistence of the left posterior cardinal vein (1911)

PERSISTENCE OF THE LEFT POSTERIOR CARDINAL VEIN. By Joun Cameron, M.D., D.Sc, F.R.S.E., Lecturer on Anatomy, Middlesex Hospital Medical School.

THE condition recorded in this paper was found in an aged female (ctat 79), and proved to be a remarkably complete case of persistence of the above vein. The post-renal segment of this vessel was particularly prominent, forming a venous channel 75 cm. long and 3 mm. wide. It took origin below from the left common iliac vein exactly at the point where this was joined by the left ilio-lumbar, and, moreover, the middle sacral vein entered directly opposite this junction. Further, it was noticed that the right ilio-lumbar vein joined the right common iliac close to its union with the inferior vena cava. This relationship, upon a closer investigation of the specimen, was found to possess great importance and interest, as the subsequent description will show. The junction of the left posterior cardinal vein with the left renal proved to be quite a meeting- place of veins; for at the same point the second left lumbar and the left ovarian veins had poured their blood into the left renal. This post-renal segment thus received the second, third, and fourth left lumbar veins ; whilst these in their turn were continued on to the inferior vena cava by wide anastomotic channels which passed posterior to the abdominal aorta.

The pre-renal segment of the left posterior cardinal vein was very minute up to the point where it was joined by the left subcostal vein. On receiving the latter vessel it assumed quite a respectable size, and was then, of course, continued on as the vena azygos minor inferior. Posteriorly, this segment communicated with the second left lumbar vein close to the union of the latter with the left renal, and, further, was joined about the middle of its course by a very small first left lumbar vein.

The pre-renal segment of the right posterior cardinal vein could likewise be defined with a tolerable degree of readiness, and was found, like the left, to communicate posteriorly with the second right lumbar vein close to its junction with the inferior vena cava, which, as it happened, was also the point of entrance of the right renal. The pre-renal segment of the right posterior cardinal vein was, as on the left side, joined by the first right lumbar vein, whilst the latter was united to its fellow by a slender Persistence of the Left Posterior Cardinal Vein 417

anastomotic channel corresponding to those of the second, third, and fourth lumbar veins.

The left ovarian vein poured its blood into the junction of the left posterior cardinal with the left renal; whilst the right vein entered the inferior vena cava immediately below the union of the right renal. The

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In the right half of the diagram the inferior vena cava has been reduced to the size of the left posterior cardinal vein in order to show that the left common iliac is the cross communication between the ilio-lumbar veins.

left capsular vein was very prominent, and joined the left renal 5 mm. to the mesial side of the junction of the left posterior cardinal, and in its turn received the blood of the left inferior phrenic vein, which would account for its unusually large size. The right capsular vein had, unfortunately, become destroyed during the process of dissection, so that its point of Junction could not be ascertained with any degree of certainty. It has

therefore not been represented in the accompanying diagram. VOL. XLV. (THIRD SER. VOL. VI.)—JULY 1911. 29 418 Dr John Cameron

After making a sketch of the specimen it was noticed that, by reducing the size of the post-renal segment of the inferior vena cava so as to make it equal to that of the left posterior cardinal vein, an almost. symmetrical diagram would result, which to a tolerable extent might represent the condition existing during embryonic life. The right half of the diagram exhibits the arrangement that resulted, and it has been put alongside the original sketch for the purpose of comparison. It may be noted that the right and left lumbar veins all possess cross communications, whilst the renal, spermatic, and possibly the capsular veins of opposite sides have one common anastomotic trunk, which becomes the mesial portion of the left renal vein. The most remarkable point elicited, however, was that the left common iliac became demonstrated by this plan as the corresponding cross communication between the right and left ilio-lumbar veins. From this standpoint the mode of development of the left common iliac vein becomes readily understood. Thus the ilio-lumbar veins, like those more anterior, exhibit the characteristic tendency to become connected together across the mesial plane. In a similar way, the mesial communication between the

_ first intercostal veins probably develops into the left innominate vein. This view would certainly appear to explain why the first intercostal vein drains into the corresponding innominate.

I was much interested in the fact that-in this specimen the right ilio- lumbar vein joined the corresponding common iliac close to its union with the inferior vena cava. In none of the textbooks of anatomy could I find any reference to the exact point of junction of this vein. I therefore made a dissection of the subjects available in the dissecting room, and found that in every case the vein entered at the point just indicated. However, I will not feel satisfied about this until a much larger number of subjects have been examined.

The condition described in this communication corresponds very closely to that shown in fig. 1, illustrating Professor A. Robinson’s paper! on the abnormalities of the venous system. This observer states at the close of his memoir that “the left common iliac vein is formed partly by the left posterior cardinal, and partly by a dilated anastomosis between the two posterior cardinals.” The present specimen permits one to amplify this statement, for it indicates clearly how much is developed from the left posterior cardinal, and how much from the cross communication. That portion between the junction of the left ilio-lumbar vein and the vena cava is developed from the cross communication, whilst the distal portion is derived from the left posterior cardinal.

1 Studies in Anatomy from the Anatomical Department of the Owens College, vol. i., 1891, p. 197. Persistence of the Left Posterior Cardinal Vein 419

Another interesting outcome of the study of the present specimen is, that the posterior cardinal veins form a system quite distinct from the ascending lumbar veins. This fact has been already pointed out by Dr R. J. Gladstone in the last number of this Journal. The latter veins connect the lumbars in front of the roots of the transverse processes, and are thus separated from the cardinals by the psoas muscle. This statement can be readily confirmed by a study of transverse sections of human embryos during the second or third months.

Professor C. J. Patten + has recently described a complete persistence of the post-renal segments of the cardinal veins. He depicts all four lumbar veins as joining these segments. This is unusual. It did not occur in any of the specimens figured by Professor Robinson, nor in the present specimen. From a study of Professor Patten’s diagram, it looks as if his lowest lumbar veins were really ilio-lumbar, in which case the other three would be the second, third and fourth lumbar veins, and this would represent the normal occurrence. ,

The main results arrived at from a study of the present specimen are :—

(1) That portion of the left common iliac between the junction of the left ilio-lumbar vein and the inferior vena cava is developed as a cross communication between the right and left ilio-lumbar veins, corresponding to those connecting the lumbar segmental veins. The remainder of the left common iliac is developed from the left posterior cardinal vein.

(2) These anastomotic channels are all post-aortic, with the exception-of that connecting the right and left renal veins.

(3) The ascending lumbar vein is quite distinct from the cardinal system, and is situated on the roots of the lumbar transverse processes ; whilst the posterior cardinal veins rest mainly on the vertebral bodies.

(4) The renal and spermatic or ovarian veins (and possibly the capsular) possess only one common cross communication, which becomes the mesial portion of the left renal vein.

(5) The anastomotic relationship in this specimen indicates that the proximal ends of both right and left second lumbar veins are formed from the corresponding cardinal veins.

(6) In this specimen the left capsular vein had not joined the posterior cardinal, but had entered the left renal directly.

1 Anat. Anz., Bd. xxxiv., 1909, p. 189.