ANOMALIES OF VENAE CAVAE SUPERIORES IN AN ORANG RALPH E. CHASE AND CHARLES F. DEOARIS Department of Anatomy, University of Oklahoma School of Medicine ONE FIOURL Anomalies of the venae cavae superiores are fairly frequent in man, but, as far as we have been able to ascertain, have not been reported in other primates. The specimen described here comprises the heart and great vessels from orang-utan (Pongo pygmaeus), this being one of seven such specimens added to our stock of primate material through the kindness of Dr. A. H. Schultz, Baltimore, who writes that the orang-utans were collected by him in British North Borneo on the Asiatic Primate Expedition of 1937. Three other hearts from orang-utan had been made available to us from various sources by Doctor Schultz. VENAE CAVAE SUPERIORES The peculiar arrangement of the venae cavae superiores dorsal in this specimen from orang-utan a re shown as diagram in figure 1. Both venae cavae appear reduced in size, as compared with the other great vessels and with the heart. The vena cava sinistra, a s usual in cases where it persists, is found emptying into the left extremity of the sinus coronarius. As it approaches the heart it receives a vein from the atrium sinistrum. However, this vein at its entrance into the vena cava has a lumen far wider than can be RCcredited to the small area drained by it and the few tributaries which i t receives; also a laceration renders part of its wall incomplete. Fr o m these circumstances and in view of the 61 AYERlCAX J O U B N A L OF I’HYSICAIr ANTHROPOLOOY, VOL. aSXIV, NO. 1 JULY-SLLPRMBCR, 1938 62 R. X. CIIBSE AND C. F. DE GARIS relatively small size of veins traceable from the remnant of the left lung directly into the atrium sinistrum, the possibility is suggested that a vein from the upper part of the left lung entering the vena cava sinistra has been torn away at the point marked G in figure 1. While the presence of such a vein in this case is suppositional, it is a matter of report that the vena cava superior sinistra usually does receive a n aberrant tributary from the left lung before emptying into the sinus coronarius. F G B Fig. 1 A, vena cava superior dextra: B, eonfluenee of upper vv. pulmonales dextrae et azygos; C, atrium dextrum; D, vena eava inferior; E, sinus coronarius; P, vena cava superior sinistra; G , vein from atrium sinistrum, possibly receiving a vena pulrnonalis sinistra; H, vv. pulmonales sinistrae; I, v. pulmonalis dextra. Though there is no evidence of a vena anonyma sinistra, the exact mode of formation of the venae cavae superiores cannot be stated, since all the vessels (except the aorta) had been cut across at levels indicated in figure 1. Having blocks of pulmonary tissue at the roots of the lungs still attached to the specimen, we are able to identify an unsual arrangement of veins on the right side. Tributaries from upper portions of the right lung form by confluence a large vein, which joins VENAE CAVAE SUPERIORS I N A N ORANQ 63 the vena cava superior dextra a short distance above the entrance of this latter into the atrium dextrum. Among the veins forming this confluence is a large one entirely free of lung tissue ;this by reason of its size, relations and caval connection is regarded as the vena azygos. A single large vena pulmonalis from lower portions of the right lung empties directly into the atrium sinistrum. Examination of the atrium dextrum shows a completed fossa ovalis, there being no valve-like remnant of the foramen, as often seen in man. The septum ventriculorum is likewise complete. Within the atrium dextrnm is found a male nematode approximately 150 mm. long, identified as Acanthocheilonema (Dipetclonema) perstans. This species of the Filaridae is said to abound in tropical regions of the world as a parasite in man and other primates, with tendency to infest the peritoneal and pleural membranes. I t s intermediate host is reported to be one of the Culicoides. For information regarding this parasite of the orang-utan we are indebted to Dr. A. J. Sheldon of the Department of Bacteriology. DISCUSSION Since no literature exists on anomalies of the vena cavae superiores in primates other than man, it must suflice here to cite but a few reports of general interest from human anatomy. The papers by McCotter ('15), Poynter ('23) and Chase ('38) and the atlas by Abbott ('36) cover classification, developmental interpretations, associated cardiac and other malformations and a list of reported cases. *4s has often been pointed out, the failure or suppression of the embryonic thymicothyroid veins connecting right and left precardinal channels gives rise to right and left caval trunks. The vena cava superior sinistra and the sinus coronarius together thus represent the left duct of Cuvier and the adjacent part of the left precardinal vein. Regarding connections of the superior caval trunks with pulmonary veins-in the present case of the orang-utan merely suggestive on the left side but fully demonstrated on 64 R. E. CHASE AND C. F. Da GARIS the right-it may be said that various anomalies of this kind are attributed t o early plexiform connections between precardinal and pulmonary veins, or between these latter and the postcardinal portion of the vena azygos. Anastomosis between upper pulmonary veins and the terminal or azygos part of the postcardinal vein fully account for the confluence'of the venae pulmonales et azygos entering the vena cava superior dextra. It is a matter of interest that of our ten orang-utan hearts two exhibit anomalous conditions considered worthy of record in man. The specimen described here is one; the other is a case of pericardial patency and partial ectocardia in a newborn orang-utan (De Garis, '34). Also branches of the aortic arch and especially patterns of the coronary circulation, which we are now studying, vary so widely as to confirm the impression that the orang-utan is a primate having even a stronger predilection for vascular anomalies than has man. Further, as compared with rhesus monkey, which we have examined in large series for coronary patterns (Chase, '38) and for aortic branches (De Garis, '35, '38), the orang-utan appears much more variable. Nor did we find in any specimen of rhesus, among the 266 examined, such gross anomalies as those of the venae cavae superiores or that of the patent pericardium, both of which occur in our series of ten orangutan specimens. We must say, with a degree of disappointment, that one rather frequent anomaly of the human aortic arch, viz., the arteria subclavia dextra as the fourth branch, has not thus f a r appeared in any of our primate material. VEZTAE CAVAE SUPERIORS I S A S ORANG 65 BUMMABY In a specimen of the heart and great vessels of orang-utan (Pongo pygmaeus) are found the following venous anomalies : the vena cava superior sinistra persists as a tributary of the left extremity of the sinus coronarius. Conditions of a vein from the atrium sinistrum to the vena cava superior sinistra suggest, but do not satisfactorily demonstrate, a vena pulmonalis sinistra emptying at this site. The vena cava superior dextra, a short distance above its entrance into the atrium dextrum, receives a large tributary made up of veins from the upper part of the right lung in confluence with the vena azygos. Veins from the lower part of the right lung unite to form a single trunk emptying into the atrium sinistrum. Examination of the interior of the heart shows no patent foramen ovale; the septum ventriculorum is complete. From this case and from other considerations the orangutan appears to be highly variable as to its vascular system. N o previous reports on anomalous venae cavae superiores in orang-utan are found. LITERATURE CITED ABBWT,M. E. 1936 Atlas of Congenital Cardiac Disease. 62 pp. Am. Heart ABBOC.,N. Y. CEASE, R. E. 1938 The coronary arteries in 266 hearts of rhesus monkey. Am. J. Phys. Anthrop., XXIII, 299-320. 1938 A case of persistent vena cava superior sinistra, associated with patent foramen ovale and saphenous varicosity. Proc. Internat. Ass. Med. Museums. (In press.) DE GABIS, C. F. 1934 Pericardial patency and partial ectocardia in a newborn orangutan. Anat. Rec., LIX, 69-82. 1935 Patterns of the aortic arch in a series of 133 macaques. J. Anat., LXX, 149-158. 1938 Branches of the aortic arch in 153 rhesus monkeys (second series). Anat. Rec., LXX, 251-262. McConz~, R. E. 1915 Three cases of persistence of the left superior veiia cava. X, ,371-383. Anat. k. POYNTCB, C. W. M. 1923 Congenital anomalies of the arteries and veins of the human body with bibliography. University studies, XXII, 1-106. Lincoln, Nebraska.