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Unilateral Fused Kidney with Non-Obliteration of the Hypogastrics
UNILATERAL FUSED KIDNEY WITH NON-OBLITERATION OF THE HYPOGASTRICS ELMER HESS From the Urological and Pathological Departments of Hamot Hospital, Erie, Pennsylvania
A four-month-old infant died of tuberculous meningitis at one of the local hospitals and was autopsied. The pathologist whom I have interested in renal anomalies in particular, found a unilateral fused kidney with three distinct kidney pelves. Two of the pelves in the lower pole of this kidney fused to the common ureter (fig. 2), which crosses the aorta above the bifurcation (fig. 3), extends down over the iliac vessels and inserts normally into the right ureteral meatus (fig. 3). The ureter from the upper pelvis descends anteriorly to its fellow (fig. 3), running in a groove on the kidney, dips over the crest of the ileum, crossing the iliac vessels normally and empties into the left ureteral meatus (fig. 3). The blood supply to the kidney is unusual inasmuch as there is a distinct renal artery to the lower kidney area, and one to the upper kidney area (figs. 1, 2, and 6), while the one renal vein that can be found to drain the entire kidney crosses the artery in the normal situation, particularly over the kidney pelvis (figs. 1, 3 and 5). There was a fine plexus of veins leaving the upper pole of the kidney posteriorly, which emptied into a large vein that crossed the artery posteriorly and empties into the posterior wall of the vena cava (fig. 4). In dissecting out the ureters, I discovered that the two internal iliacs course down underneath the broad ligament and up over the fundus of the bladder just under the peritoneum and anastomosed over the fundus of the bladder (figs. 1 and 3). From the left hypogastric, the left umbilical artery extends upward toward the umbilicus where it has been severed (figs. I and3). Thereisadistinct communication between the arteries from both sides (figs. 1 and 3), and the superior vesical artery comes from the non-obliterated 695
696
ELMER HESS
Fm. 1.
PHOTOGRAPH OF ACTUAL SPECIMEN
1, Unilateral fused left kidney; 2, left suprarenal; 3, aorta; 4, right suprarenal; 5, venacava; 6, ovarian vein; 7, left ureter, upper; 8, right ureter, lower; 9, lower (right renal artery); 10, upper (left renal artery); 11, anterior renal vein; 12, pelvis, upper half of kidney; 13, pelvis, lower half of kidney; 14, right common iliac; 15, left common iliac; 16, left external iliac; 17, right external iliac; 18, right internal iliac; 19, left internal iliac; 20, left hypogastric; 21, right hypogastric; 22; superior vesical artery; 23, left umbilical artery; 24, anastomosis right and left non-obliterated hypogastrics; 25, urinary bladder.
UNILATERAL FUSED KIDNEY
FIG.
2.
697
UNILA'rERALFUSEDKIDNEY. PYELOGRAMTAKEN AFTER DEATH, SHOWING NORMAL UPPER LEFT PELVIS A:-SD A BIFURCATED LOWER PELVIS
698
FIG.
ELMER HESS
3.
DRAWING SHOWING THE APPROXIMATE RELATIONSHIPS OF THE UNILATERAL FUSED KIDNEY, lTs VASCULAR SUPPLY, AND THE ANASTOMOSIS OF THE NON-OBLITERATED H YPOGASTRICS OVER THE FUND US OF THE BLADDER
FIG. 4. SHOWING THE POSTERIOR SURF ACE OF THE UPPER p ART OF THE UNILATERAL FUSED KIDNEY WITH A SERIES OF SMALL VEINS DRAINING FROM THE UPPER PELVIS, EMPTYING INTO A RATHER LARGE TRUNK POSTERIOR TO THE AORTA
This large trunk empties into the posterior wall of the venacava.
UNILATERAL FUSED KIDNEY
699
FIG. 5. SHOWING THE ANTERIOR VENOUS DRAINAGE, Two BRANCHES DRAINING THE LOWER HALF OF THE HORSESHOE KIDNEY, FORMING A COMMON TRUNK WHICH UNITES WITH A LARGE BRANCH FROM THE UPPER HALF, HAVING A SMALL ADRENAL VEIN EMPTYING INTO IT TO FORM THE ANTERIOR RENAL VEIN
FIG. 6. SHOWING THE LEFT RENAL ARTERY SUPPLYING THE UPPER HALF OF THE UNILATERAL FUSED KIDNEY AND THE RIGHT RENAL ARTERY COMING FROM THE RIGHT SIDE OF THE AORTA, TWISTING ACROSS THE AORTA WITH THREE BRANCHES SUPPLYING THE LOWER POLE OF THE UNILATERAL FUSED KIDNEY
700
FIG. 7.
ELMER HESS
POSSIBLE E1IBRYOLOGICAL ORIGIN OF CONDITION DESCRIBED (AFTER PATTEN)
1. Start ·with normal symmetrical condition. 2. Form transverse anastomosis. 3. One of umbilicals drops out beyond the anastomosis. 4. Condition described if I interpret it correctly.
UNILATERAL FUSED KIDNEY
701
hypogastric artery and inserts itself into the fundus of the bladder (figs. 1 and 3). There is no obliteration of the hypogastric arteries (figs. 1 and 3). The vessels are about the same calibre as that of the internal iliac throughout and the non-obliterated umbilical artery is practically of like calibre (figs. 1 and 3). The situation interested me so much that I wrote to a group of anatomists for their comment. Dr. J. P. McMurrich of the University of Toronto, says: As to the condition of the umbilical artery it is evidently new to me and I have never had occasion to look up whatever literature there may be bearing on the case. Is it not possible, however, that what you term the superior vesical artery is really the proximal part of the urachus'?
Dr. H. D. Senior, Department of Anatomy, New York University, says: You probably know more about such cases as this than I do, but since I had occasion to go over the literature of single umbilical arteries a few years ago, it may be of some help to Dr. Hess if I note the references I have bearing upon singleness of umbilical arteries and intraabdominal connections with them. Intra-abdominal connections between the umbilical arteries have been described by G. D. Ajutolo (Bull. delle Sc. Mediche, Bologna, Ser. 2, vol. 2, 1891) and by H. Bardeleben (Anat. Anz., Bd. 10, 1895). Bovero examined 281 infantile and late fetal cords and found a single umbilical artery (doubtless due to an original cross branch) in twenty of them (Internat. Monatschr. f. Anat. u. Physiol., Bd. 12, 1895). Single umbilical arteries in the cord are not very uncommon in man and appear to be the rule in many of the other mammals. The earliest single human umbilical artery I know of is that of the 6 mm. embryo 1075 of the Carnegie Institution Collection. It is double within the abdomen as it is in most cases that have been recorded at birth or later. In some cases, however, the intra-abdominal part of one of the umbilical arteries has apparently become obliterated and lost at a comparatively early state of development. To judge from the observations of W. N. F. Woodland (J. Anat., v. 55, 1920) and B. K. Das (J. Anat., 56, 1921), late obliteration of the intra-abdominal part of the umbilical arteries is a common occurrence in mammals other than man. It is probably commoner in man than
702
ELMER HESS
is generally supposed. If Dr. Hess has access to infantile and adolescent material, perhaps he might care to investigate the question further . Such an investigation is desirable. Dr. T. W. Todd of Western Reserve University, turned my letter over to Dr. N. W. , Ingalls, of Western Reserve University, who said: The kidney condition is very interesting, and, I imagine, rather uncommon in representing the fusion of two, one of which had a double pelvis and ureter. As regards the vascular anomalies, there is not much that I can say, nor do I know how rare the condition may be. Rarely there is only one artery in the umbilical cord, and I have seen this condition once in a young embryo. The peculiar position, and singleness of the superior vesical artery might well be related in some way, perhaps or there were other atypical pelvic conditions with which it might be associated. The fact that the vesical artery comes off in the midline according to your diagram would explain the non-obliteration of the hypogastrics on either side. From the point of union of the hypogastrics, upward, I take it, the single umbilical artery is obliterated. The large size of the hypogastrics in the neighborhood of the bladder here, might mean that they are supplying more blood, more organs, than are usually taken care of by the superior vesicals. Dr. Todd also turned a copy of my letter over to Dr. B. M. Patten of the Department of Histology and Embryology, Western Reserve University, who said, Dr. Todd showed me your letter and sketch and asked me to give you any information I could on the curious relations of the hypogastrics and the superior vesical artery. It seems to me that Dr. Ingall's note calls attention to the most critical point in this picture as far as the persistence of the lumen of the hypogastrics is concerned. The retention of this patency would seem, as he points out, to be quite definitely correlated with the peculiar origin of the superior vesical arteries. Both this part of the picture and the single umbilical artery could be accounted for embryologically on the hypothesis of a transverse anastomosis forming between the originally paired umbilical and the subsequent suppression of one member of the pair. That, of course, is the sort of thing that regularly happens in the disappearance of one of the originally
UNILATERAL FUSED KIDNEY
703
paired umbilical veins. Retention of a lumen in the umbilical branch beyond the anastomosis would be rather surprising. There is no great volume of statistical data on the time of the obliteration of the lumen of the umbilical arteries, but such as there is indicates that it is usually gone by the end of the first month after birth (Scammon and Norris, Anatomical Record, vol. 15, 1918). Dr. R. E. McCotter, Professor of Anatomy, University of Michigan, sends the following interesting communication. I was very much interested in reading the description of the specimen which you recently observed in an autopsy. Vi!e have in our collection quite a large number of kidney anomalies and one or two similar to the one you describe. It would appear that the ureter, arising apparently from two pelves, is merely the subdivision of the pelvis of the kidney into two major calyces, and if the division takes place far enough down, there is either a partial or complete double ureter. In reference to the anomaly of the hypogastric arteries which you mention, I believe that you have a very unusual arrangement. I have failed to see such a variation in the thousands of specimens we have had in the laboratory. Dr. R. J. Terry, Washington University, says: I am glad you called my attention to the anomaly of the umbilical arteries for it is as you suspected a rare condition. I have never seen one. While I have not made a careful search of the literature, you may be interested to know that fusion of the two non-obliterated umbilical arteries is referred to in Henle's Anatomy, in Poirier, and in Todd and Bowman's Encyclopedia of Anatomy and Physiology. Henle's reference is to Otto who records fusion of the two vessels to form a single trunk among the rare variations. Todd and Bowman refer to the French anatomist, Cloquet, whose work is not in our library. The statement occurs in Henle that the fusion may take place at various levels between the origin of the arteries from the internal iliac on up to the placenta. Dr. W. Sullivan of the University of Wisconsin, says: The conditions that you describe in the infant of four months are very interesting and not at all common. In 1923, Dr. C. W. M. Poynter of
704
ELMER HESS
the University of Nebraska published as a university publication a very complete discussion of congenital anomalies of vessels. I am quoting a paragraph from his paper which deals with the situation in which you are interested. The iliacs are the proximal persistent portion of the umbilical arteries. A number of observations have been made in which one of the umbilical arteries was lacking in the cord, Fleischmann (1815); or was obliterated, Bremer (1906). Mouchotte (1900) reported finding no artery on the left distal to the hypogastric, which was rudimentary. Other cases were reported by Boudant (1828) and Tschaussow (1886), Duckworth (1907), see Argaud (1904). The umbilical situated in a deep fold of peritoneum was seen by Kelch (1803) and Otto (1830); Otto (1824) found the umbilical remaining patent to the umbilicus in an adult.
Dr. E. A. Boyden of the University of Minnesota, says: Both Dr. Jackson and myself were much interested in the case you describe. Neither of us have ever seen this condition in the dissecting room. One wonders if the patency of this umbilical end of the arteries was not due to anastomoses with vessels of the body wall in the region of the umbilicus.
Dr. B. C. Harvey of the University of Chicago, says: Your letter to Professor Bensley was referred to me. I have been seeking for a report of the frequency with which anastomosis between the two umbilical arteries has actually been recorded. So far I have been unable to find such a report in the literature. Various degrees of fusion of the kidneys are rather common. Many reports and descriptions appear in the literature and a paragraph is devoted to the subject in Morris' "Anatomy." The separation of the kidney pelvis into two parts is not at all uncommon, nor is multiplicity of renal arteries. There may be as many as six on one side and the lower ones sometimes come from the common iliac arteries. Veins crossing the vertebral column behind the aorta and communicating with the renal veins are not uncommon. They are constant in the embryo and appear in the figures of Davis in Volume X of the American Journal of Anatomy. Those veins are in the nature of anastomoses between the two posterior cardinal veins which in turn communicate with the sub-cardinal and renal veins. It is not uncommon for one of the umbilical arteries to remain patent
UNILATERAL FUSED KIDNEY
705
as far as the umbilicus for many months after birth. Occasionally the inferior epigastric artery or the superior vesical artery is given off from such an artery. I have seen evidence of an anastomoses between the right and left umbilical arteries or rather the remnants of them, but as I said, I have no figures as to the percentage of frequency of their occurrence. An explanation of their presence is afforded at least partially by the fact that the allantois in embryonic and early fetal stages is a relatively large structure all the way to the umbilicus. Its blood supply comes throughout from these two arteries. After the involution and shrinking of the upper part of the allantois, the lower part remains. Its arteries come from the umbilical arteries as the superior vesical branches but above them are remnants of branches to the upper levels of the allantois. These go to the urachus and they may anastomose across the midline producing the condition which you report. In Poirier and Charpey's "Anatomie" you will find a statement of the fact that these umbilical arteries are often patent in infants and occasionally even in adults. It is also common for the two arteries to fuse into one common trunk extending some little distance below the umbilicus.
In conclusion I wish to thank Dr. E. L. Armstrong, Pathologist at Hamot Hospital for spotting and saving this interesting specimen and for his cooperation in preparing the specimen for publication and report. I also want to thank the following Anatomists to whom I wrote and whose opinions are embodied in this report: R. E. McCotter, M.D., B. M. Patten, M.D., J. P. McMurrich, M.D., H. D. Senior, M.D., N. W. Ingalls, M.D., R. J. Terry, M.D., W. S. Sullivan, M.D., E. A. Boyden, M.D., B. C. Harvey, M.D., C. R. Bardeen, M.D., R.R. Bensley, M.D., H. M. Evans, M.D., C. C. Huber, M.D., C. M. Jackson, M.D., and T. W. Todd, M.D.
A four-month-old infant died of tuberculous meningitis at one of the local hospitals and was autopsied. The pathologist whom I have interested in renal anomalies in particular, found a unilateral fused kidney with three distinct kidney pelves. Two of the pelves in the lower pole of this kidney fused to the common ureter (fig. 2), which crosses the aorta above the bifurcation (fig. 3), extends down over the iliac vessels and inserts normally into the right ureteral meatus (fig. 3). The ureter from the upper pelvis descends anteriorly to its fellow (fig. 3), running in a groove on the kidney, dips over the crest of the ileum, crossing the iliac vessels normally and empties into the left ureteral meatus (fig. 3). The blood supply to the kidney is unusual inasmuch as there is a distinct renal artery to the lower kidney area, and one to the upper kidney area (figs. 1, 2, and 6), while the one renal vein that can be found to drain the entire kidney crosses the artery in the normal situation, particularly over the kidney pelvis (figs. 1, 3 and 5). There was a fine plexus of veins leaving the upper pole of the kidney posteriorly, which emptied into a large vein that crossed the artery posteriorly and empties into the posterior wall of the vena cava (fig. 4). In dissecting out the ureters, I discovered that the two internal iliacs course down underneath the broad ligament and up over the fundus of the bladder just under the peritoneum and anastomosed over the fundus of the bladder (figs. 1 and 3). From the left hypogastric, the left umbilical artery extends upward toward the umbilicus where it has been severed (figs. I and3). Thereisadistinct communication between the arteries from both sides (figs. 1 and 3), and the superior vesical artery comes from the non-obliterated 695
696
ELMER HESS
Fm. 1.
PHOTOGRAPH OF ACTUAL SPECIMEN
1, Unilateral fused left kidney; 2, left suprarenal; 3, aorta; 4, right suprarenal; 5, venacava; 6, ovarian vein; 7, left ureter, upper; 8, right ureter, lower; 9, lower (right renal artery); 10, upper (left renal artery); 11, anterior renal vein; 12, pelvis, upper half of kidney; 13, pelvis, lower half of kidney; 14, right common iliac; 15, left common iliac; 16, left external iliac; 17, right external iliac; 18, right internal iliac; 19, left internal iliac; 20, left hypogastric; 21, right hypogastric; 22; superior vesical artery; 23, left umbilical artery; 24, anastomosis right and left non-obliterated hypogastrics; 25, urinary bladder.
UNILATERAL FUSED KIDNEY
FIG.
2.
697
UNILA'rERALFUSEDKIDNEY. PYELOGRAMTAKEN AFTER DEATH, SHOWING NORMAL UPPER LEFT PELVIS A:-SD A BIFURCATED LOWER PELVIS
698
FIG.
ELMER HESS
3.
DRAWING SHOWING THE APPROXIMATE RELATIONSHIPS OF THE UNILATERAL FUSED KIDNEY, lTs VASCULAR SUPPLY, AND THE ANASTOMOSIS OF THE NON-OBLITERATED H YPOGASTRICS OVER THE FUND US OF THE BLADDER
FIG. 4. SHOWING THE POSTERIOR SURF ACE OF THE UPPER p ART OF THE UNILATERAL FUSED KIDNEY WITH A SERIES OF SMALL VEINS DRAINING FROM THE UPPER PELVIS, EMPTYING INTO A RATHER LARGE TRUNK POSTERIOR TO THE AORTA
This large trunk empties into the posterior wall of the venacava.
UNILATERAL FUSED KIDNEY
699
FIG. 5. SHOWING THE ANTERIOR VENOUS DRAINAGE, Two BRANCHES DRAINING THE LOWER HALF OF THE HORSESHOE KIDNEY, FORMING A COMMON TRUNK WHICH UNITES WITH A LARGE BRANCH FROM THE UPPER HALF, HAVING A SMALL ADRENAL VEIN EMPTYING INTO IT TO FORM THE ANTERIOR RENAL VEIN
FIG. 6. SHOWING THE LEFT RENAL ARTERY SUPPLYING THE UPPER HALF OF THE UNILATERAL FUSED KIDNEY AND THE RIGHT RENAL ARTERY COMING FROM THE RIGHT SIDE OF THE AORTA, TWISTING ACROSS THE AORTA WITH THREE BRANCHES SUPPLYING THE LOWER POLE OF THE UNILATERAL FUSED KIDNEY
700
FIG. 7.
ELMER HESS
POSSIBLE E1IBRYOLOGICAL ORIGIN OF CONDITION DESCRIBED (AFTER PATTEN)
1. Start ·with normal symmetrical condition. 2. Form transverse anastomosis. 3. One of umbilicals drops out beyond the anastomosis. 4. Condition described if I interpret it correctly.
UNILATERAL FUSED KIDNEY
701
hypogastric artery and inserts itself into the fundus of the bladder (figs. 1 and 3). There is no obliteration of the hypogastric arteries (figs. 1 and 3). The vessels are about the same calibre as that of the internal iliac throughout and the non-obliterated umbilical artery is practically of like calibre (figs. 1 and 3). The situation interested me so much that I wrote to a group of anatomists for their comment. Dr. J. P. McMurrich of the University of Toronto, says: As to the condition of the umbilical artery it is evidently new to me and I have never had occasion to look up whatever literature there may be bearing on the case. Is it not possible, however, that what you term the superior vesical artery is really the proximal part of the urachus'?
Dr. H. D. Senior, Department of Anatomy, New York University, says: You probably know more about such cases as this than I do, but since I had occasion to go over the literature of single umbilical arteries a few years ago, it may be of some help to Dr. Hess if I note the references I have bearing upon singleness of umbilical arteries and intraabdominal connections with them. Intra-abdominal connections between the umbilical arteries have been described by G. D. Ajutolo (Bull. delle Sc. Mediche, Bologna, Ser. 2, vol. 2, 1891) and by H. Bardeleben (Anat. Anz., Bd. 10, 1895). Bovero examined 281 infantile and late fetal cords and found a single umbilical artery (doubtless due to an original cross branch) in twenty of them (Internat. Monatschr. f. Anat. u. Physiol., Bd. 12, 1895). Single umbilical arteries in the cord are not very uncommon in man and appear to be the rule in many of the other mammals. The earliest single human umbilical artery I know of is that of the 6 mm. embryo 1075 of the Carnegie Institution Collection. It is double within the abdomen as it is in most cases that have been recorded at birth or later. In some cases, however, the intra-abdominal part of one of the umbilical arteries has apparently become obliterated and lost at a comparatively early state of development. To judge from the observations of W. N. F. Woodland (J. Anat., v. 55, 1920) and B. K. Das (J. Anat., 56, 1921), late obliteration of the intra-abdominal part of the umbilical arteries is a common occurrence in mammals other than man. It is probably commoner in man than
702
ELMER HESS
is generally supposed. If Dr. Hess has access to infantile and adolescent material, perhaps he might care to investigate the question further . Such an investigation is desirable. Dr. T. W. Todd of Western Reserve University, turned my letter over to Dr. N. W. , Ingalls, of Western Reserve University, who said: The kidney condition is very interesting, and, I imagine, rather uncommon in representing the fusion of two, one of which had a double pelvis and ureter. As regards the vascular anomalies, there is not much that I can say, nor do I know how rare the condition may be. Rarely there is only one artery in the umbilical cord, and I have seen this condition once in a young embryo. The peculiar position, and singleness of the superior vesical artery might well be related in some way, perhaps or there were other atypical pelvic conditions with which it might be associated. The fact that the vesical artery comes off in the midline according to your diagram would explain the non-obliteration of the hypogastrics on either side. From the point of union of the hypogastrics, upward, I take it, the single umbilical artery is obliterated. The large size of the hypogastrics in the neighborhood of the bladder here, might mean that they are supplying more blood, more organs, than are usually taken care of by the superior vesicals. Dr. Todd also turned a copy of my letter over to Dr. B. M. Patten of the Department of Histology and Embryology, Western Reserve University, who said, Dr. Todd showed me your letter and sketch and asked me to give you any information I could on the curious relations of the hypogastrics and the superior vesical artery. It seems to me that Dr. Ingall's note calls attention to the most critical point in this picture as far as the persistence of the lumen of the hypogastrics is concerned. The retention of this patency would seem, as he points out, to be quite definitely correlated with the peculiar origin of the superior vesical arteries. Both this part of the picture and the single umbilical artery could be accounted for embryologically on the hypothesis of a transverse anastomosis forming between the originally paired umbilical and the subsequent suppression of one member of the pair. That, of course, is the sort of thing that regularly happens in the disappearance of one of the originally
UNILATERAL FUSED KIDNEY
703
paired umbilical veins. Retention of a lumen in the umbilical branch beyond the anastomosis would be rather surprising. There is no great volume of statistical data on the time of the obliteration of the lumen of the umbilical arteries, but such as there is indicates that it is usually gone by the end of the first month after birth (Scammon and Norris, Anatomical Record, vol. 15, 1918). Dr. R. E. McCotter, Professor of Anatomy, University of Michigan, sends the following interesting communication. I was very much interested in reading the description of the specimen which you recently observed in an autopsy. Vi!e have in our collection quite a large number of kidney anomalies and one or two similar to the one you describe. It would appear that the ureter, arising apparently from two pelves, is merely the subdivision of the pelvis of the kidney into two major calyces, and if the division takes place far enough down, there is either a partial or complete double ureter. In reference to the anomaly of the hypogastric arteries which you mention, I believe that you have a very unusual arrangement. I have failed to see such a variation in the thousands of specimens we have had in the laboratory. Dr. R. J. Terry, Washington University, says: I am glad you called my attention to the anomaly of the umbilical arteries for it is as you suspected a rare condition. I have never seen one. While I have not made a careful search of the literature, you may be interested to know that fusion of the two non-obliterated umbilical arteries is referred to in Henle's Anatomy, in Poirier, and in Todd and Bowman's Encyclopedia of Anatomy and Physiology. Henle's reference is to Otto who records fusion of the two vessels to form a single trunk among the rare variations. Todd and Bowman refer to the French anatomist, Cloquet, whose work is not in our library. The statement occurs in Henle that the fusion may take place at various levels between the origin of the arteries from the internal iliac on up to the placenta. Dr. W. Sullivan of the University of Wisconsin, says: The conditions that you describe in the infant of four months are very interesting and not at all common. In 1923, Dr. C. W. M. Poynter of
704
ELMER HESS
the University of Nebraska published as a university publication a very complete discussion of congenital anomalies of vessels. I am quoting a paragraph from his paper which deals with the situation in which you are interested. The iliacs are the proximal persistent portion of the umbilical arteries. A number of observations have been made in which one of the umbilical arteries was lacking in the cord, Fleischmann (1815); or was obliterated, Bremer (1906). Mouchotte (1900) reported finding no artery on the left distal to the hypogastric, which was rudimentary. Other cases were reported by Boudant (1828) and Tschaussow (1886), Duckworth (1907), see Argaud (1904). The umbilical situated in a deep fold of peritoneum was seen by Kelch (1803) and Otto (1830); Otto (1824) found the umbilical remaining patent to the umbilicus in an adult.
Dr. E. A. Boyden of the University of Minnesota, says: Both Dr. Jackson and myself were much interested in the case you describe. Neither of us have ever seen this condition in the dissecting room. One wonders if the patency of this umbilical end of the arteries was not due to anastomoses with vessels of the body wall in the region of the umbilicus.
Dr. B. C. Harvey of the University of Chicago, says: Your letter to Professor Bensley was referred to me. I have been seeking for a report of the frequency with which anastomosis between the two umbilical arteries has actually been recorded. So far I have been unable to find such a report in the literature. Various degrees of fusion of the kidneys are rather common. Many reports and descriptions appear in the literature and a paragraph is devoted to the subject in Morris' "Anatomy." The separation of the kidney pelvis into two parts is not at all uncommon, nor is multiplicity of renal arteries. There may be as many as six on one side and the lower ones sometimes come from the common iliac arteries. Veins crossing the vertebral column behind the aorta and communicating with the renal veins are not uncommon. They are constant in the embryo and appear in the figures of Davis in Volume X of the American Journal of Anatomy. Those veins are in the nature of anastomoses between the two posterior cardinal veins which in turn communicate with the sub-cardinal and renal veins. It is not uncommon for one of the umbilical arteries to remain patent
UNILATERAL FUSED KIDNEY
705
as far as the umbilicus for many months after birth. Occasionally the inferior epigastric artery or the superior vesical artery is given off from such an artery. I have seen evidence of an anastomoses between the right and left umbilical arteries or rather the remnants of them, but as I said, I have no figures as to the percentage of frequency of their occurrence. An explanation of their presence is afforded at least partially by the fact that the allantois in embryonic and early fetal stages is a relatively large structure all the way to the umbilicus. Its blood supply comes throughout from these two arteries. After the involution and shrinking of the upper part of the allantois, the lower part remains. Its arteries come from the umbilical arteries as the superior vesical branches but above them are remnants of branches to the upper levels of the allantois. These go to the urachus and they may anastomose across the midline producing the condition which you report. In Poirier and Charpey's "Anatomie" you will find a statement of the fact that these umbilical arteries are often patent in infants and occasionally even in adults. It is also common for the two arteries to fuse into one common trunk extending some little distance below the umbilicus.
In conclusion I wish to thank Dr. E. L. Armstrong, Pathologist at Hamot Hospital for spotting and saving this interesting specimen and for his cooperation in preparing the specimen for publication and report. I also want to thank the following Anatomists to whom I wrote and whose opinions are embodied in this report: R. E. McCotter, M.D., B. M. Patten, M.D., J. P. McMurrich, M.D., H. D. Senior, M.D., N. W. Ingalls, M.D., R. J. Terry, M.D., W. S. Sullivan, M.D., E. A. Boyden, M.D., B. C. Harvey, M.D., C. R. Bardeen, M.D., R.R. Bensley, M.D., H. M. Evans, M.D., C. C. Huber, M.D., C. M. Jackson, M.D., and T. W. Todd, M.D.