Illustrated Encyclopedia of Human Anatomic Variation: Opus II: Cardiovascular System

Origin of the Variable Branches of Internal Iliac Artery.

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

C.I. = common iliac; E.I. = external iliac; I.I. = internal iliac; A.D. = anterior division; P.D. = posterior division; Hyp.T = hypogastric trunk; I.L. = iliolumbar; L.S. = lateral sacral; G l. = (superior) gluteal; S.V. = superior vesical; I.V. = inferior vesical; Ut. = uterine; V. = vaginal; M.H. = middle rectal; Ob. = obturator; I.P. internal pudic (pudendal); Sc. = sciatic (inferior gluteal).

Upper left: There is no hypogastric trunk, as the arteries which usually compose it spring separately from the anterior division.

Upper right:In this illustration the hypogastric trunk is a branch of the internal iliac before its division.

Lower:Considered by the Authors to be typical, based upon their present report.

Hypogastric trunk.- 56 observations. In 37 (66%) it was a branch of the anterior division; in 13 (23.3%) no trunk was present; while in the remaining 6 (10.7%) it came from the internal iliac before its division into two.

Ilio-lumbar.- 57 observations. In 35 (61.4%) it rose entirely from the internal iliac; in one of these cases the artery was double; in 17 (29.8%) it rose directly from the posterior division in common with the lateral sacral. In 2 cases, besides the one already recorded, the artery was doubled: in the first of these one twig rose from the posterior division, and the other from the sciatic (inferior gluteal), in the second, the upper twig came from the internal iliac, and the lower from the posterior division. In one case the ilio-lumbar was a branch of the obturator, itself a branch of the internal iliac.

Lateral sacral.- 53 observations. In 27 (50.9%) the two arteries of one side rose by a common trunk; in 25 (47.2%) there were two distinct arteries on one side, while in one case three arteries were present. Of the 27 cases in which the single trunk was present, it came from the posterior division in 25 (92.6), and from the internal iliac in 2 (7.4%). Of the 25 cases in which there were two arteries, they both came from the posterior division 17 times (68%), both from the internal iliac once (4%), while in the remaining 7 instances they rose from different parts, the upper one usually coming from the internal iliac, the lower from the posterior division. In 9 cases, as has already been recorded, one or both the lateral sacrals came off in common with the iliolumbar.

The (superior) gluteal artery.- with their classification, this artery must always be the terminal branch of the posterior division.

The sciatic (inferior gluteal) artery,- as Jastschinski has pointed out, may be a branch of the anterior or posterior division, or may come off from the internal iliac between these divisions. The authors have 56 observations of it; in 42 of these (75%) it rose from the anterior division; in 12 (21.4%), from the posterior division; while in only one case (1.8%) did it come off from the internal iliac. Occasionally (3 cases) the artery is doubled, and in one of these one branch came from the anterior, and the other from the posterior division; this case they have, therefore, not included in either category.

The internal Pudic (pudendal) is necessarily always a branch of the anterior division. It is remarkable that no cases of accessory pudendals were recorded in this study.

Middle Hæmorrhoidal (rectal).- 45 observations. In 15 cases (33.3%) it rose by itself from the anterior division; in 10 (22.2%) it came off separately from the hypogastric trunk; in 6 (13.3%) it had a common origin with the pudendal; in 4 (8.9%) it rose in common with the obturator; in 2 cases (4.4%), in common with the sciatic (inferior gluteal) (in 1 of these the inferior gluteal was a branch of the posterior division); in 2 cases, in common with the inferior vesical; in 2 with the uterine, and in 1 with the superior vesical. In 2 cases it rose by itself from the posterior division, and in 1 case there were 2 middle rectal arteries,1 coming from the anterior division, the other from the posterior division in common with the lateral sacral.

Inferior vesical.- 58 observations. In 40 cases (68.9%) it rose as a separate vessel from the hypogastric trunk; in 13 (22.4%) as a separate vessel from the anterior division; in 2 (3.5%) as a separate vessel from the internal iliac. In 3 cases (5.2%) the vessel rose in common with others, twice with the middle rectal, and once with the superior vesical: in the 2 former cases, however, there were 2 inferior vesical arteries, 1 of which came directly from the hypogastric trunk.

Superior Vesical.- 58 observations. In 44 cases (75.9%) it rose from the hypogastric trunk; in two of these cases the artery was doubled; in 9 cases (15.5%) it came from the anterior division, in 1 of these the artery was doubled; in 4 cases (7%) it came from the internal iliac; and in 1 case, in common with the middle rectal, from the hypogastric trunk.

Obturator. - 55 observations. In 20 cases (36.4%) it rose as a separate trunk from the anterior division; in 10 (18.1 %) from the deep (inferior) epigastric; in 9 (16.4%) separately from the hypogastric trunk; in 8 (14.5%) from the posterior division; in 5 (9.1 %) from the internal iliac before its division; while 3 cases (5.4%) it rose in common with the middle rectal, 2 of these coming from the anterior division, and 1 from the hypogastric trunk. In connection with the origin of the obturator from the deep (inferior) epigastric, the authors found that out of 138 subjects examined at Guy's Hospital the obturator was only seen to rise from the inferior epigastric 11 times (8%); while Quain's Anatomy it is stated that this origin is found in nearly 30%. The percentage which this investigation gives (18.1%) is nearly midway between these, but it is evident that further observation is required.

Uterine.- 18 observations. In 9 cases (50%) the artery rose from the hypogastric trunk as a single separate vessel; in 3 (16.9%) it was a separate branch of the anterior division; in 3 (16.9%) it came off with the inferior vesical from the hypogastric trunk; in 1 case it rose in common with the middle Hæmorrhoidal (rectal) from the anterior division. In 2 cases there were 2 uterine arteries: in the first of these 1 arose from the hypogastric trunk, and the other from the anterior division; in the second, 1 rose with the inferior vesical, the other with the middle Hæmorrhoidal (rectal).

The lower figure of an internal iliac artery which this investigation makes the authors regard as typical.

from Parsons and Keith, 1897.

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