Illustrated Encyclopedia of Human Anatomic Variation: Opus II: Cardiovascular System: Arteries: Abdomen: Variations in Branches of Celiac Trunk:

Inferior Renal Polar Arteries

Ronald A. Bergman, PhD
Adel K. Afifi, MD, MS
Ryosuke Miyauchi, MD
Peer Review Status: Internally Peer Reviewed

Inferior renal polar arteries have been implicated as an etiologic factor in a form of hydronephrosis correctable by surgery. Aberrant renal arteries are common in fused kidneys (horseshoe- dumbbell- or disc-shaped): two to six such arteries are characteristically longer or shorter than usual. The unusual vessels may originate from the aorta, gonadal, common iliac, middle sacral, external or internal iliac, or superior or inferior mesenteric arteries. An inferior renal polar artery may give rise to a gonadal artery. There are reports in the literature of seven, eight, and ten arteries supplying horseshoe-shaped kidneys, but such findings, are very rare. In one study, the vascularization pattern of a dumbbell-shaped kidney had seven arteries: four from the aorta, one from each common iliac artery, and one from the left testicular artery. Studies indicate that 84% of fused kidneys occur in males.

Eisendrath (1920) provided the following practical conclusions from published statistics.
"It is important for the surgeon to remember that the examination of 1237 kidneys by various investigators reveals the fact that upper polars from the renals occurred in 68, or 16%, of 518 kidneys. Upper polars from the aorta were found in 68, or 0.5%, and lower polars from the aorta in 71, or nearly 0.6%, of 1237 kidneys. Lower polars from the iliacs were found in only 6, or 0.04%, of the 1237 kidneys."

According to Eisendrath's series of dissections, one can expect to find upper polar arteries arising from the main renals in about one kidney out of five. Upper polars arising from the aorta were found in one out of about 17 kidneys and lower polars (from the aorta and iliacs) in one kidney out of about 7 kidneys.

Adding together the observations of all previous investigators and our own (Eisendrath's) we find that (a) upper polars arising from the main renals occur in about one out of about 200 kidneys; (b) upper polars arising from the aorta in about one out of about 190 kidneys; and (c) lower polars from the main renal, the aorta, or common iliacs in one out of about 185 kidneys. Although accessory polar vessels did not occur as frequently as stated by Quain, i.e., 20%, they are found often enough to be constantly borne in mind during operation."

The Retropelvic Vessels

"The tradition still exists that one needs only to guard against injury of a retropelvic artery which pursues a more or less typical course in the sinuses formed at the point where the kidney tissue slightly overlaps the renal pelvis. That there may be (a) variations from this arch-like distribution of the artery and (b) that one or more large vein, even the main renal, may cross our field of operation are two anatomical facts which deserve more widespread knowledge in order to avoid injury to these anomalous vessels during pyelotomy.

In Albarran's book, published in 1910, reference is made to retropelvic artery and vein to the effect that the main renal artery may divide into pre- and retropelvic trunks of equal size, and that the retropelvic artery on its way to the sinus gives off branches similar to those arising from the prepelvic artery. His only statement in regard to the retropelvic vein is that it is not constant - was found in 5 of 29 cases by Hauch - and finally that it may prove a source of trouble during pyelotomy.

In view of the results of Eisendrath's study, he believes one must abandon the view that the posterior aspect of the renal pelvis is the avascular field we have generally believed it to be. The distribution of the prepelvic vessels seldom, if ever, enters into consideration in the operation of pyelotomy, because the route of election is through the less vascular field. In a total of 218 kidneys, the following observations of variations of the retropelvic vessels of surgical importance were made:

A. Retropelvic Artery Alone.

1. Division of the single main renal artery into equal-sized branches was found very frequently.

2. When there were two main renal arteries, one of these frequently became retropelvic, i.e., the latter arose directly from the aorta instead of the main renal artery. This was found in 5 out of 124 kidneys.

3. The main renal or one of two renal arteries was found to be retropelvic in 2 out of 124 kidneys.

4. The retropelvic artery had its origin from an accessory lower polar artery in 2 out of 124 kidneys.

5. A retropelvic artery directly from the aorta was found in 2 out of 124 kidneys.

6. The main retropelvic artery does not cling in an arch-like manner to the renal sinus. This generally accepted course of the vessel may be described as the high type to distinguish it from various combinations which were found in both the Illinois and Harvard dissections. These extra vessels which may give rise to troublesome bleeding during pyelotomy are (a) a high middle and low or fan-like distribution found twice in 124 kidneys; (b) a high and middle type of branching found twice in 124 kidneys; (c) a high and low type found twice in 124 kidneys; (d) a single artery crossing the middle of the pelvis, found four times in 124 kidneys; and finally (e) a middle and low type found seven times in 124 kidneys.

B. Retropelvic Veins.

1. One large vein arising from the vena cava was found five times in 218 kidneys, passing directly across the back of the renal pelvis.

2. The main renal vein divided into equal-sized pre- and retropelvic branches in 3 of 218 kidneys. The retropelvic branch passes directly across the pelvis and, as in the case of the preceding variation, could be easily injured during pyelotomy.

3. The most important variation, so far as the veins were concerned, was that the main renal vein, instead of being prepelvic, was retropelvic in 9 out of 218 kidneys.

C. Retropelvic Vein and Artery.

1. One large vein directly from the vena cava and one artery directly from the aorta crossed the back of the pelvis in one of 94 kidneys.

2. Two large veins directly from the vena cava and one artery from the aorta crossed the back of the pelvis in one of 94 kidneys.

Types of Pelvis.
Observations made as to the relative frequency of the various types of renal pelvis revealed the following;

1. The single or ampullary pelvis was found in 84 (89%) out of 94 kidneys.

2. The divided or bifid type was found in 7 (8%) out of 94 kidneys. In 4 of these it was present on both sides.

3. The trifid type was found in 3% of 94 kidneys."

Authors note: Eisendrath's references to a book by Albarran (1910) and to the work of Hauch were not found in his bibliography.

Image 42, Image 126A, Image 126B, Image 126C, Image 126D, Image 213, Image 218, Image 220, Image 407

Superior (Splenic)

Image 269

Section Top | Title Page

URL: http://www.anatomyatlases.org/