REVIEW OF LITERATURE. Jastschinski (1891 a) found that only the vessels in the first category showed sufficient regularity in origin to enable them to be grouped into definite Types, of which he described four. Adachi (1928) modified the method slightly, adding a fifth type of variation and included certain subtypes, in a study of the internal iliac artery and its branches in Japanese subjects. His scheme is as follows (Fig. 1): Type I. The superior gluteal artery arises separately from the internal iliac artery, and the inferior gluteal and internal pudendal vessels are given off by a common trunk. If the latter divides within the pelvis it is considered to be Type I a, whereas if the bifurcation occurs below the pelvic floor it is classified as Type l b. Type II. The superior and inferior gluteal arteries arise by a common trunk and the internal pudendal vessel separately. In this category, as in the previous one, two subtypes are described. Type Ha includes those specimens in which the trunk common to the two gluteal arteries divides within the pelvis, and Type Ilb those in which the division occurs outside the pelvis. Type III. The three branches arise separately from the internal iliac artery. Type IV. The three arteries arise by a common trunk. The subtyping in this group is based on the sites of origin of the superior gluteal and the internal pudendal arteries from the parent stem. In Type IVa the trunk first gives rise to the superior gluteal artery before bifurcating into the other two branches; In Type IVb the internal pudendal is the first vessel to spring from the common trunk, which then divides into superior and inferior gluteal arteries. Type V. The internal pudendal and the superior gluteal arteries arise from a common trunk, and the inferior gluteal has a separate origin. Ashley & Anson (1941), who carried out a similar investigation to that of Lipshutz (1918) in American subjects (Whites and Negroes), employed the umbilical artery in addition to the three large parietal trunks for 'typing' and the obturator artery for 'subtyping' the internal iliac variations. Since the variations in origin of the parietal branches of the internal iliac artery are of great surgical importance, but have not been previously investigated in a large series of British subjects, it was decided to undertake this extensive study. On account of the marked variations in origin of the obturator artery the findings for this vessel will be described separately from those pertaining to the superior gluteal, inferior gluteal and internal pudendal arteries, and the latter will be classified according to Adachi's method. The existing arterial variations can be as well appreciated by this approach as by employing the obturator artery as an additional factor in 'subtyping', as in the classifications of Lipshutz (1918) and Ashley & Anson (1941). Although the mode of origin of the three large parietal vessels conforms to one of four types in the present investigation, an arrangement in which the superior gluteal artery arises proximal to the common trunk for the inferior gluteal and internal pudendal arteries is comparatively constant (58-5 %). This finding is in agreement with Adachi (1928) and Ashley & Anson (1941). Jastschinski (1891a), however, notes a Type I incidence in only 38 % of his specimens. The obturator artery is much more variable. All investigators are agreed that the most common site of origin of this vessel is from the anterior division of the internal iliac artery as a direct branch; present findings, however, differ from those of previous observers in the comparatively low incidence of an obturator artery arising from the inferior epigastric artery (19.5 %), and the high incidence of a vessel with a double origin (6.5 %). The incidence of an origin from the inferior epigastric artery varies from 20 to 30 % in most series (Jastschinski, 1891 b; Quain, 1844; Levi, 1901; Pick, Anson & Ashley, 1942). Most observers describe the obturator vessel as having a double origin in about 1 % of cases (Quain, 1844; Dwight, 1895; Pick et al. 1942). Adachi (1928) pointed out that an obturator artery with two roots probably occurs more frequently than previous findings have indicated, this discrepancy being due to the difficulty of recognizing one of the roots when of very small size. In such instances, the larger root, which generally arises from the inferior epigastric artery, would probably be regarded as an obturator artery arising by a single stem. The superior gluteal, inferior gluteal and internal pudendal arteries are comparatively constant in their origins, conforming to a Type I arrangement on the Adachi scale in 58*5 % of cases, a Type III pattern being found in 22-5 % and Type II in 15-3 %. Type IV is less frequent and occurs in 386 % of specimens. In 52-7 % of instances, a similar origin of vessels is noted on both sides.1 The obturator artery is more variable and arises as a direct branch from the anterior division of the internal iliac artery in 41-4 % of instances, from the inferior epigastric artery in 19-5 %, from the superior gluteal artery in 10 %, from the inferior glutealinternal pudendal trunk in 10 % and by a double origin in 6-4 %. In only 23 % of instances is a similar origin noted on both sides.1 REFERENCES ADACHI, B. (1928). Das Arteriensystem der Japaner, Bd. II. Kyoto. Supp. to Acta Scholae Medicinalis Universitatis Imperalis in Kioto, 9 (1926-7). ASHLEY, F. L. & ANSON, B. J. (1941). The hypogastric artery in American Whites and Negroes. Amer. J. phys. Anthrop. 28, 381-891. DWIGHT, T. (1895). Statistics of variations with remarks on the use of this method in anthropology. 1. Origin of the obturator artery. Anat. Anz. 10, 209-215. JASTSCHINSKI, S. (1891a). Die typischen Verzweigungsformen der Arteria hypogastrica. Int. Mschr. Anat. Physiol. 8, 111-127. JASTSCHINSKI, S. (1891b). Die Abweichungen der Arteria obturatoria nebst Erklarung ihres Enstehens. Int. Mschr. Anat. Physiol. 8, 366-379. LEVI, G. (1901). Osservazioni sulle variazioni delle arterie iliache. Monit. zool. ital., 12, no. II, 332-341. LIPSHUTZ, B. (1918). A composite study of the hypogastric artery and its branches. Ann. Surg. 67, 584-608. PICK, J. W., ANsoN, B. J. & ASHLEY, F. L. (1942). The origin of the obturator artery; study of 640 body halves. Amer. J. Anat. 70, 317-343. QUAIN, R. (1844). The Anatomy of the Arteries of the Human Body. London: Taylor and Walton. 1. J. L. Braithwaite, Variations in origin of the parietal branches of the internal iliac artery, J Anat. 1952 October; 86(Pt 4): 423–430. In the vast majority of cases, the OBA originates within the pelvis from external iliac or the hypogastric (internal iliac artery), the anterior or posterior division of the latter, or a branch of either division (Parson & Keith, 1897; Pick et al; Brathwaite, 1952). The most common type of variation is the anastomosis between OBA of internal iliac origin & inferior epigastric of external iliac origin. Out of these only in 30% of cases this anastomosis opens up to become accessory obturator artery, replacing the normal branch from the internal iliac artery (Bergman et al). Pick et al. have documented that the OBA arising from the posterior division of the internal iliac artery can occur in 3.28% of cases in western population. Although similar (same site of origin) to the Pick et al's findings, our observation of incidence of origin of left OBA is only 0.5% (one out of 316 pelvises). Further the exact site of origin has been documented in this study, which is at a distance of 8mm distal to the point of bifurcation of the internal iliac artery. This rare abnormality in Indian population may be due different set of environmental or genetic factors. Thus influencing the development of pelvic vessels differently1 . 1. Dinesh Kumar & Gayatri Rath, Anomalous Origin of Obturator Artery from the Internal Iliac Artery, Int. J. Morphol., 25(3):639-641, 2007. Parson, S. F. G. & Keith, A. Sixth annual report of the committee of collective investigation of the Anatomical Society of Great Britain and Ireland, 1895-96. J. Anat. Physiol, 31:31-44,1897 Brathwaite, J. L. Variations in origin of the parietal branches of the Internal iliac artery. J. Anat. 86:423-30,1952. Bergman, R. A.; Thompson, S. A.; Afifi, A. K. & Saadeh, F. A. Compendium of Human Anatomic variation: catalog, Atlas and World Literature. Urban and Schwazenberg, Baltimore and Munich, 1988. 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. Kurume Med J. 1998;45(4):333-40. A statistical study of the branching of the human internal iliac artery. Yamaki K, Saga T, Doi Y, Aida K, Yoshizuka M. Department of Anatomy, Kurume University School of Medicine, Japan. This study is based on the dissections of 645 pelvic halves of Japanese cadavers. The branching of the internal iliac artery was classified according to Adachi's classification (1928), and the data was compared with previous reports. Type I was predominant in this, as well as, in previous studies. During the course of the present study, some branching forms were different from the types in Adachi's classification. Therefore, this classification was modified into 5 types and 19 groups. Type I-Group 1 was most frequently observed in the modified Adachi's classification, however, the frequency was less than 50% (46.8%). To clarify the basic branching pattern of the original internal iliac artery and to simplify the classification for medical purposes, a new classification system was designed. The superior gluteal, inferior gluteal and internal pudendal arteries were defined as the major branches of the internal iliac artery, and the umbilical artery was excluded from this group. The branching of the internal iliac artery was classified into 4 groups. Almost 80% of the present specimens were included in Group A of the new classification, namely, the internal iliac artery dividing into two major branches, the superior gluteal artery and the common trunk of the inferior gluteal and internal pudendal arteries. This type of branching seemed to be the basic branching pattern for the original internal iliac artery. Ann Anat. 2006 Nov;188(6):541-6. Morphometry of the internal iliac artery in different ethnic groups. Fătu C, Puişoru M, Fătu IC. Department of Anatomy and Clinical Anatomy, University of Medicine and Pharmacy Gr. T Popa, 16 University Street, 6600 laşi, Romania. email@example.com The internal iliac artery supplies the pelvic organs, as well as the osseous and muscular components of pelvic walls. The goal of our study is a statistical analysis of the internal iliac artery and its branches compared to the data recorded in the Literature. A total of 100 internal iliac arteries were dissected, 60 arteries from male and 40 from female individuals. The results point out differences in Length and caliber between males and females. Comparative analysis of our data with similar studies shows differences in the length of the internal iliac artery in Romanian patients compared to English and Japanese people. In conclusion, our results suggest a vascular variability in different ethnic groups. Comparative study of human internal iliac artery based on adachi classification W. H. Roberts, Gene L. Krishingner Department of Anatomy, Schools of Medicine and Dentistry, Loma Linda University, Loma Linda, California Abstract This study is based upon a dissection of 167 pelvic halves of Caucasian bodies. The distribution of the four major types, as based upon the Adachi classification, corresponds closely to that of the Western populations. The composite group has a distribution almost identical with the Japanese population studied by Adachi. No instances of the rare Type V were encountered. One unusual specimen which we have designated as Type VI is described.