Department of Anatomy, Govt. Medical College, Patiala, *Amritsar. INDIA
Arterial arches of hand are very important for orthopaedicians as well as microvascular surgeons. Variations encountered in these are so numerous that Poirier finds it difficult to establish a type. The present study was conducted in 50 upper limbs at Govt. Medical College, Amritsar to find out the pattern of arterial arches of hand. Variations are found more often in superficial palmar arch than the deep one, later being more or less constant. SPA was found to be single in 94% limbs (complete in 78%, & incomplete in 16%.) In 6% of limbs, a double SPA was encountered, proximal complete (radio ulnar in 4% & mediano-ulnar in 2%) & distal incomplete. Amongst the DPAs, all were complete but in one case (2%), it was limited upto 2nd intermetacarpal space only with no contribution further laterally.
In general, it was confirmed that size of the 2 arches is inversally proportional to each other.
All the variations encountered have an ontogenic basis which has been discussed along with their clinical implications.
Key words: Superficial Palmar arch, Deep palmar arch, Palmar arterial arches.
Arterial supply to the man's hand, his most important earning tool is derived from two anastomotic arches, superficial et deep formed by the anastomosis between two main arteries of forearm i.e. radial, ulnar & their branches; in the palm. These were studied as early as 1753, by Haller, a swiss anatomist & poet while notable variations were described by Tiedman (1831) which were explained later, on ontogenic basis by Meyer (1881) & Singer (1933). It was Manners Smith (1910) who made a comparative study of arteries of hands in primates & concluded that many of the variations noted in man represent a retention or reappearance of primitive patterns. Tandler (1897); Jaschtschinski (1897); Adachi (1928); Fracassi, (1945) Coleman & Anson (1961) are the few among those to name, who have worked on arteries of hand.
Superficial Palmar Arch - This anastomosis is fed mainly by the ulnar artery, entering the palm with the ulnar nerve, anterior to the flexor retinaculum and lateral to the pisiform, passing medial to the hamate's hook, then curving laterally to form an arch, convex distally (Williams et al, 1999) across the middle 1/3 of the palm (Massie, 1944), and in level with a transverse line through the distal border of the fully extended pollicial base (Boyd et al, 1956 and Williams et al, 1999). About a third of the superficial palmar arches are formed by the ulnar artery alone; a further third are completed by the superficial palmar branch of the radial artery and a third either by the arteria radialis indicis, a branch of arteria princeps pollicis or by the median artery (Coleman & Anson, 1961). It is covered by the palmaris brevis and palmar aponeurosis and it is superficial to the flexor digiti minimi, branches of the median nerve and to the long flexor tendons and lumbrical muscles (Anson and Maddok, 1952; Williams et al, 1999).
This arch shows a number of variations as reported by Dubreuil chambardel (1926); Huber, (1930); Coleman & Anson, (1961) & Mozersky et al (1973). According to Poirier (1886), Variations in SPA are so numerous that it is difficult to establish a type.
Deep Palmar Arch: It is formed by anastomosis of the end of the radial with the deep palmar branch of the ulnar artery. It forms a flatter curve than the superficial arch (Spalteholz). The radial artery typically emerges between 2 heads of adductor pollicis in its course across the palm, Then it crosses the bases of metacarpal bones and interossei (Williams, et al, 1999).
This arch is found to be comparatively less variable than SPA (Coleman & Anson, 1961; Karlsson & Niechajev, 1982).
Apart from these two main arches two more arches Palmar & Dorsal Carpal arches give twigs to the palm & dorsum of hand. All these arches anastomose freely with each other so much so that wounds of palmar or carpal arches can be source of severe bleeding, difficult to achieve haemostasis. It is also because of occasional difficulty in finding & securing both ends of divided vessel (Huber, 1930; Treves & Rogers, 1947).
Accepting the fact that extensive arterial anastomosis in the hand leads to profuse bleeding from its wounds; Lockhart et al (1959) emphasize that for the same reasons, healing is also very rapid. They further call for paying particular attention to the superficial position of termination of ulnar artery and superficial palmar arch while making incisions to evacuate pus from the hand.
Dubreuil (1926) and Mozersky et al (1973) asserted the importance of understanding variations of the superficial palmar arch for the purpose of microvascular repair and re-implantation.
Keeping the importance of these variations in mind, this study was designed to find out the pattern of palmar arterial arches in the region which may help not only the anatomists but also orthopaedicians & microvascular surgeons.
50 Upper limbs belonging to 25 cadavers (M.F.: 19:6) of the Anatomy Department, of Govt. Medical College, Amritsar, comprised the material for study. These were embalmed with an embalming fluid containing lead oxide to colour the arteries red & labelled from 1-25 with letters (R) or (L) corresponding to right or left limb respectively & letters (M) or (F) corresponding to male or female respectively. Exposure of different palmar arches was achieved following classical incisions & dissection procedures provided by Cunningham's Manual of Practical Anatomy, (Romanes, 1999).
Palmar aponeurosis was exposed and separated from flexor retinaculum, divided proximally and reflected distally cutting the septae which pass backwards from its edges. This exposed the superficial palmar arch which was cleaned to study the pattern. All other branches of radial and ulnar arteries in the palm were also studied.
The tendons of flexor digitorum superficialis were divided at the level of heads of metacarpals and reflected proximally upto wrist. This exposed the deep palmar arch which was cleaned to study the pattern.
Any variation from the normal patterns were observed, noted and where required, photographed.
Superficial Palmar arch: Out of the 50 limbs, single SPA are found in 47 (94%) limbs which included 39 limbs (78%) with a complete arch & 8 limbs (16%) with an incomplete one. In the former group classical radio ulnar type was encountered in 38 (76%) limbs while one (2%) limb had ulnar type of arch. In the later (incomplete arch) group, 6 limbs (12%) had a blood supply from both ulnar artery & superficial palmar branch of radial artery but without an anastomosis with each other (Photograph 1) while in 2 limbs, instead of superficial palmar branch of radial, it was median artery which was a source of blood supply along with ulnar artery again without anastomosis with each other (Photograph 2).
The arrangement of intercommunications betwixt ulnar artery and radial or median artery as the case may be; (radio-ulnar in limb number 1ML and 12 MR; mediano-ulnar in limb no. 11 MR) and branching out of palmar interdigital arteries has set apart 3 cases deviant from normal which are christened as double superficial palmar arch. All the 3 double superficial palmar arches had 2 constitutent components - a proximal and a distal where proximal arch was invariably complete and situationally where superficial palmar arch is expected, the distal component was incomplete in all the 3 cases, but was responsible for palmar interdigital arteries to emnate from and so considered as an incomplete superficial palmar arch, the 2 component arches together constituted double superficial palmar arch.
Deep Palmar arch: It is found to be less variable as compared to superficial palmar arch. In all the 50 dissections, it was a complete arch. The ulnar artery gave 2 deep palmar branches in all cases but both of these contributed to formation of deep palmar arch only in 10% instances. In majority of specimens i.e. 52% it was only inferior deep palmar branch of ulnar artery which formed deep palmar arch, the superior being lost in hypothenar eminence. In 36% of dissections, it was superior ramus which contributed to formation of deep palmar arch.
In one limb the radial artery dipped in 2nd intermetacarpal space and took part in formation of deep palmar arch with superior deep palmar branch of ulnar artery.
Owing to a large number of variations in SPA, Poirier (1886) had found it extremely difficult to establish a type, while Adachi (1928) has described 3 types of superficial palmar arch.
Huber (1930) groups the superficial palmar arch into 2 classes:
Coleman and Anson (1961) elaborated more on superficial palmar arch and reclassified it as follows :
Type A: The classical radio ulnar arch is formed by superficial palmar branch of radial artery and the larger ulnar artery. It was found in 34.5% dissections (36% by Weathersby, 1954; and 30% by Anson, 1966).
Type B: This arch is formed entirely by ulnar artery. It was found in 37% cases.
Type C: Mediano ulnar arch is composed of ulnar artery and an enlarged median artery. It was found in 3.8% specimens (8% by Anson, 1966).
Type D: Radio-mediano-ulnar arch in which 3 vessels enter into the formation of arch. It was found in only 1.2% dissections.
Type E: It consists of a well formed arch initiated by ulnar artery and completed by a large sized vessel derived from deep arch. The latter vessel comes to superficial level at the base of the thenar eminence of join the ulnar artery. It was found in 2% cases.
When the contributing arteries to the superficial arch do not anastomose or when the ulnar artery fails to reach the thumb and index finger, the arch is incomplete, Such type of arch was found in 21.5% cases. It can be further divided into 4 types.
Type A: Both superficial palmar branch of radial artery and ulnar artery take part in supplying palm and fingers but in doing so, fail to anastomose. It was found in 3.2% cases.
Type B: Only the ulnar artery forms superficial palmar arch. The arch is incomplete in the sense that the ulnar artery does not take part in the supply of thumb and index finger. It was found in 13.4% dissections.
Type C: Superficial vessels receive contributions from both median and ulnar arteries but without anastomosis. It was found in 3.8% specimens.
Type D: Radial, median and ulnar artery all give origin to superficial vessels but do not anastomose. It was found in 1.1% cases.
If the results of present study are compared with earlier authors, (Table I) it is seen that in 38 cases (76%) out of 39 (78%) the complete SPA was of type A i.e. radio ulnar type whereas in Coleman & Anson (1961) series it was found in 34.5% dissections with type B in another 37%. In this context, comments of Adachi (1928) are worth a mention who commented that differentiation between these two types is very difficult as it depends upon observer's estimate as to what constitutes a minimal contribution by radial artery. It may probably explain part of discrepancy in this observation.
Incomplete arch (group II) was encountered in 8 limbs (16%) of the present study. While it was of type A in 12% & type C in 4%, Coleman & Anson (1961) found it to be of type B in majority (13.4%) (See Table 1).
|Coleman & Anson (1961)||Weathers by (1954)||Anson (1966)||Present study|
* In the rest of 6%, the superficial palmar arch was double
In 3 of the limbs (6%) double SPA was encountered (radioulnar in two & mediano ulnar in one limb) out of these one has been already reported by Patnaik et al (2000 a).
The superficial palmar branch of radial artery failed to develop fully consequent upon median artery persistance as in one case. So only a very small superficial palmar arch developed between persistent median artery and ulnar artery or the radial and ulnar arteries and this superficial palmar arch was insufficient to supply palmar interdigital branches. In all 3 cases, the proximal component of double superficial palmar arch remained rudimentary. So the first interdigitial was still being supplied by median or radial artery (as is the case) while the ulnar artery continued to supply 4th, 3rd and 2nd interdigital spaces as a major chunk giving the appearance of 2nd superficial palmar arch which is incomplete and falls in Type B or C of Group II of Coleman and Anson (1961). This is in consonence with Arey's (1957) views that anomalous blood vessels may be due to:
Double superficial palmar arch is very important clinically in cases of bleeding from any of the interdigital branches of ulnar artery. The surgeon may ligate the ulnar artery at a point proximal to usual level of superficial palmar arch expecting the blood supply through 4th, 3rd, 2nd interdigital arteries to be cutt off as an incomplete distal superficial palmar arch was encountered. Because of an alternate route via proximal complete superficial palmar arch, the result in such a case is bound to be different. The situation may be thus very embarrasing and trying one.
Another variation seen in superficial palmar arch was mediano ulnar type of superficial palmar arch. It is to be noted that the source for both the feeding vessel in this type of arch is ulnar artery proper. In cases of bleeding from palm, if ulnar artery is ligated at its origin close to the bifurcation of brachial artery, the blood flow in this arch via both these routes gets completely cut off. Then the only source of blood supply is via radial artery, deep palmar arch and then through perforating arteries indicating their importance. The radial artery is being used for transplant surgery in cases of coronary artery disease so one should be careful under such circumstances that if radial artery is removed then ulnar artery cannot be ligated as then the blood supply to hand will be totally jeopardized.
had classified deep palmar arch as follows :
Group I: Complete arch: It was found in 97% cases and further divided into 4 types:
Type A: The deep palmar arch is formed by the deep palmar branch of the radial artery which anastomoses with superior deep palmar branch of ulnar artery. The latter follows the deep branch of ulnar nerve into the palm. It was found in 34.5% dissections.
Type B: The deep palmar branch of radial artery anastomoses with the inferior deep palmar branch of ulnar artery. This is the commonest pattern encountered in 49% of dissections.
Type C: Here both deep palmar branches of ulnar artery join the deep palmar branch of radial artery to complete the arch. It was found in 13% of specimens.
Type D: It is formed by superior deep palmar branch of the ulnar artery which anastomoses with an enlarged superior perforating artery of the 2nd interspace. There is also a contribution from the Ist interspace which despite its small size helps to complete the arch. It was found only in 0.5% cases.
Group II: Incomplete arch: It was found in 3% cases only and can be further divided into:
Type A: The inferior deep branch of ulnar artery anastomoses with the perforating artery of the 2nd interspace. The deep supply to the thumb and radial border of index finger is derived from deep palmar branch of radial artery. It was found in 1.5% dissections.
Type B: The deep arterial supply to thumb and the index finger are derivatives of deep palmar branch of radial artery which in turn anastomosis with a perforating artery of 2nd space. The arch is incomplete because the deep branch of ulnar artery ends in an anastomosis with perforating artery of 3rd interspace. It was found in 1.5% of cases.
|Sr. No.||Type of deep palmar arch
Coleman & Anson (1961)
|(Coleman & Anson, 1961)||Present Study (2000)|
|5||Deviant from, Coleman & Anson (1961) classification||0.0||2.0%|
*In rest of their 3% dissections, it was of incomplete type (group II).
Table 2 shows that finding of present study are comparable to those of Coleman & Anson (1961) except that no arch of incomplete type (Group II) was encountered in the present study. Rather one entirely different type of arch was found in one limb (2%) i.e. limb No 13ML, where radial artery dipped in 2nd intermetacarpal space to form DPA with superior deep palmar branch of ulnar artery. (Patnaik et al, 2000 b) This type of DPA doesn't fall in any of Coleman & Anson's classification but is a classical retention of atavistic pattern where the main artery dipped in the 2nd intermetacarpal space as part of catella volaris proximalis of primates & contributed to the small DPA in a typical primate fashion of archus volaris profundus. (Patnaik et al, 2000b).
In group I, Type A, B and C of their classification, the radial artery passes through first inter metacarpal space,. while here it was passing through 2nd intermetacarpal space. In Type D, the superior deep palmar branch of ulnar artery anastomoses with enlarged superior perforating artery of 2nd intermetacarpal space with a small contribution from first interspace to complete the arch. Contribution from the first intermetacarpal space was not found in the present case, and it was the radial artery proper and not an enlarged superior perforating artery which passed through 2nd intermetacarpal space. In group II type A of Coleman and Anson (1961), it is inferior deep palmar branch of ulnar artery which anastomoses with perforating artery of 2nd space and deep supply to thumb and radial border of index finger is from deep palmar branch of radial artery, whereas in the present case, it was superior deep palmar branch of ulnar artery completing the arch and the deep supply to thumb and radial border of index finger was from superficial palmar branch of radial artery. In group II type B, deep arterial supply to thumb and radial border of index finger are derivatives of deep palmar branch of radial which anastomoses with perforating artery of 2nd space, deep palmar branch of ulnar anastomosing with perforating artery of 3rd space. This is also entirely different from the present case.
Thus the deep palmar arch in limb number 13ML, does not fall in any of the types of Coleman and Anson (1961) and the limb is unique in itself exhibiting a different type of deep palmar arch not described earlier.
In none of the cases, deep palmar arch was absent unlike the earlier reported prevalence of 0.5% by Jaschtschinski (1897) and a report by Poteat (1986) where it was absent.
To conclude, hand is supplied by SPA & DPA, SPA is found as a single entity in 94% of limbs while in the other 6% limbs a definable double superficial palmar arch is observed, the term christened by Patnaik et al, 2000a. It is seen that all the variations observed have some ontogenic basis and are clinically important.
On the other hand DPA was found to be more or less constant with little variations, except for one limb in which it was strikingly different from the rest being limited laterally upto 2nd intermetacarpal space only with no communication or contribution whatsoever further laterally. In toto, it is better developed in limbs with incomplete SPA & vice versa & the size of the 2 arches is inversaly proportional to each other.
Photograph 1: Incomplete radio ulnar type of superficial palmar arch (Group II, Type A) (r-radial artery; u-ulnar artery; I to IV - interdigital branches)
Photograph 2: Incomplete mediano-ulnar type of superficial palmar arch (Group II, Type C) (r-radial artery; ma-median artery; mn-median nerve; u-ulnar artery)