Venous anatomy of the thumb The venous anatomy of 20 thumbs (10 pairs) was detailed by latex injection. The thumbs were studied on the dorsal, palmar, radial, and ulnar surfaces. Characteristic patterns were found; these included a dominant longitudinal network, palmar veins within the pulp, oblique veins at the interphalangeal joint on the radial side, and a web space veln, A layered vascular pattern with a superficial fine network overlying a deeper system was noted. Cross sections were taken at the metacarpophalangeal joint and at the proximal and distal phalanges. The distribution of the vessels in cross section reveals consistent dorsal veins at all levels, as well as palmar veins distal to the interphalangeal joint in all thumbs. Palmar veins were present over the length of the proximal phalanx in more than 65% of the thumbs. (J HArm SURG 1991;16A:I063-8.)
Hani S. Matloub, MD, Kevin M. Strathy, MD, James R. Sanger, MD, and N. John Yousif, MD, Milwaukee, Wis.
RIGHT
The thumb is the most important digit of the hand, and replantation of the severed thumb when possible is recommended. A cause of replantation failure is venous obstruction, and a thorough knowledge of the venous anatomy can help minimize this complication. Several reports have studied the veins in the hand and digit': 2 and have reported a ladder type of network, but specific locations of the vessels were not reported.
Methods The arterial and venous systems of 20 fresh cadaver hands were filled with blue latex. Adequate venous filling was achieved by placement of a tourniquet around the forearm, ligation of the ulnar artery, and injection into the radial artery. After injection of 50 ml of latex, the hands were frozen for 24 hours before dissection. After thawing, the skin of the thumb, the thenar eminence, and the first dorsal web space was removed by sharp dissection. Care was taken to preserve all vascular channels other than the most super-
ULNAR
RADIAL
DORSAL
ULNAR
RADIAL
MCP
PP
DP
f!0.. ® Fig. 1. Representative venous patterns in each of the dorsal, palmar, radial, and ulnar planes. Note cross sections at the metacarpophalangealjoint and proximal and distal phalanges.
From the Department of Plastic and Reconstructive Surgery Medical College of Wisconsin, Milwaukee, Wis. Received for publication May 20, 1985; accepted in revised form March 28, 1991. No benefits in any form have been received or will be received from a commercial party related dirctly or indirectly to the subject of this article. Reprint requests: Hani S. Matloub, MD, Department of Plastic and Reconstructive Surgery, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226.
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ficial dermal vessels. Differentiation of the arteries and veins was noted by the observation that the arterial system contained more latex. Location of all vessels between 0.5 and 3 mm in diameter was mapped. The thumbs were then inspected from the dorsal, radial, palmar, and ulnar surfaces, and the venous patterns were recorded (Fig. 1). Cross sections of the thumbs were then examined, and the venous distribution was THE JOURNAL OF HAND SURGERY
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Fig. 2. There are several longitudinal veins on the dorsum of the thumb. ranging from between 2 mm and 3 mm at the MP joint (a) to 0.5 mrn at the nail matrix (b).
noted . The three levels most commonly injured were selected: the metacarpophalangeal (MP) joint, the proximal phalanx just proximal to the condyles, and the distal phalanx halfway between the interphalangeal (IP) joint and the nail bed. Similarities between the right and left thumbs of each pair were noted. Results Dorsal veins. The origin of the dorsal system began with small veins at the distal aspect of the nail sulcus and the eponychial fold. These veins coalesced into four to eight large vessels at the level of the IP joint. Proximal progression produced a continual decrease in the number of veins, with an increase in their diameter. At the level of the MP joint there were always two or three veins with a diameter of I to 1.5 mm. Even at the level of the nail sulcus, vessels less than I mm in diameter were consistently found (Fig. 2, a and band Fig. 3, a). Palmar veins. Although the palmar system is not as well developcd as the dorsal system, it is significant. Distal to the interphalangeal joint, one and usually two veins more than 0.5 mm in diameter were noted deep
within the pulp, beneath a superficial plexus of much smaller vessels connected by numerous small transverse anastomoses (Fig. 4). Proximal to the IP joint, these veins began a dorsal course up the radial and ulnar sides of the thumb to communicate with the dorsal system . In 13 of 20 thumbs, one or two veins coursed along the entire palmar aspect of the thumb into the thenar eminence (Fig. 5). When present, these veins were equally distributed along the radial and ulnar sides and measured up to 1.5 mm in diameter. Palmar veins were not always associated with the arteries as venae comitante but were superficial to them. A transverse vessel at the level of the IP joint was frequently present. Ulnar veins. The veins on the ulnar side of the thumb were oblique vessels coursing from the palmar aspect distally to the dorsum. As they coursed more proximally they became longitudinal and remained on the ulnar border (Fig. 6) . The pattern of these long oblique vessels was inconsistent, with the exception of a vein that was always present in the web space region. This web space vein ranged between I mm and 2 mm in diameter. Its location was variable in the dorsal-palmar plane;
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Fig. 3. The radial surface contains a constant oblique vein at the level of the interphalangeal joint (a). Variations such as the arcade shown in b were found. Note the fine superficial network of vessels.
however, it consistently coursed into the web space, accepting communications from both palmar and dorsal surfaces of the thumb (Fig. 6). Radial veins. As on the ulnar side, the radial veins of the thumb had oblique communicating vessels between the palmar and dorsal systems. In 19 of 20 thumbs, a very prominent oblique vein originated from the palmar system at the level of the IP joint and proceeded proximally to join the dorsal system . This constant vessel was up to 1.5 mm in diameter (Fig. 3, a).
While one oblique vessel was always present, as many as three could be found without frequent communication between them. In one thumb an arcade of veins was noted (Fig. 3, b). Longitudinal veins on the radial aspect of the thumb had an inconsistent anatomy . Cross-sectional anatomy. Cross sections at the level of the distal phalanx, proximal phalanx, and MP joint showed at least three veins at each level, with as many as 10 veins present at the MP joint.
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Fig. 4. Originating deep within pulp, palmar veins become larger as they approach skin.
While the caliber of these vessels varied greatly, the smaller the number of veins, the greater the caliber. The largest vein noted at the MP joint was 3 mm in diameter. Distal phalanx (Fig. 7, a). Four to eight veins more than 0 .5 mm in diameter were present between the IP joint and the proximal nail bed. The most prominent veins were in the palmar pulp, deep to a much finer, superficial plexus. Although at least one vein was present on the palmar aspect, a more frequent finding was one in both the radial and ulnar palmar quadrants (40% and 35%, respectively). The dorsal surface consistently contained veins larger than 0.5 mm in diameter. In the dorsal radial quadrant, two veins were present in 50% of the thumbs; in the dorsal ulnar quadrant, two veins were present in 80% of the thumbs. Proximal phalanx (Fig. 7, b). Sections just proximal to the flare of the condyles of the proximal phalanx contained between five and eight veins, and at this level the dorsal network contained more veins of a larger diameter. The oblique communicating veins on the ra-
dial and ulnar aspects of the thumb could be seen at inconstant positions along their course from palmar to dorsal. The radial palmar quadrant had one vein in 75% of the dissections and two veins in 33% . The ulnar palmar quadrant had one vein in 85% and two or more veins in 25%. One vein was present in both dorsal quadrants in all thumbs and at least 2 veins were noted in the dorsal radial (85%) and dorsal ulnar.(75%) compartments. Metacarpophalangeal joint (Fig . 7, c). At the MP joint , between three and ten veins were present, and a web space vein was a constant finding. The veins were dorsal , and palmar veins were less frequent. A radial palmar vein was present in 55% of the thumbs, and two or more veins were present in 10% of the thumbs; the ulnar palmar quadrant had one vein in 75% and two veins in 15% of the thumbs. The dorsal quadrants contained a greater number of large-caliber veins. One vein was present in each dorsal quadrant, with two or more in 80% of the radial quadrants and 75% in the ulnar quadrants.
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Fig. 5. Some palmar veins may course the entire length of the digit (arroll's). whereas others become dorsal as they course proximally.
Discussion Gray's Anatomy' and Hollingshead 's Anatomy for Surgeons' refer to two longitudinal veins along each dorsal side of the digit, but neither gives a specific description of the thumb. Kaplan's Functional and Surgical Anatomy of tile Hand' describes two venous systems of the digits, a deep and a superficial one. Specific
anatomic points in this textbook include interdigital veins and the absence of venae comitantes. These interdigital veins are presumably the same as the intercapitular veins described by Hollinghead and Gray. Lucas' performed latex injections through the bone and describe s the venous anatomy of the digits as a dorsal and palmar ladder network with lateral communicating
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b Fig. 6. There are oblique (a) and longitudinal (b) veins on the ulnar surface. Note the large vein entering the web space (arrow).
vessels. H~ makes specific reference to the commissure veins, which are similar to the intercapitular veins of Hollingshead and Gray. He also observed a terminal dorsal vein near the nail bed. In our study, the most characteristic findings were sizable palmar veins in the pulp, an oblique radial com-
municating vein arising at the level of the IP joint, a web space vein, and the dominance of the dorsal system. The presence of suitable veins for anastomosis (>0.5 mm) near the nail matrix supports the findings of Lucas.' Our study of the thumb in cross section wiII be helpful in finding veins in replantation surgery This
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DISTAL PHALANX
I
AT LEAST 1 VIEN IN ALL THUMBS. AT LEAST 21N 50%
I
AT LEAST 1 VEIN IN ALL THUMBS, AT LEAST 21N 60%
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DORSAL
_ _RADIAL
.!!'-NAR_ _
~ I
AT LEAST 1 VEIN 95%, AT LEAST 2 IN 40%
I I
AT LEAST 1 VEIN 90%, AT LEAST 21N 35%
a METACARPOPHALANGEAL JOINT AT LEAST 1 VEIN IN ALL THUMBS, AT LEAST 2 IN 70%
AT LEAST 1 VEIN IN ALL THUMBS, AT LEAST 2 IN 65%
AT LEAST 1 VEIN IN ALL THUMBS, AT LEAST 2 IN 60%
I I
AT LEAST 1 VEIN IN ALL THUMBS, AT LEAST 21N 75%
DORSAL
ULNAR
RADIAL
RADIAL
I
PALMAR
PALMAR AT LEAST 1 VEIN 750/0, AT LEAST 21N 35%
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AT LEAST 1 VEIN 65%, AT LEAST 21N 25%
b
AT LEAST 1 VEIN IN 55%, AT LEAST 2 IN 10%
I I
AT LEAST 1 VEIN 75%, AT LEAST 2 IN 15%
c
Fig. 7. Cross-section distribution of veins at the distal phalanx (a), the proximal phalanx (b), and the metacarpophalangeal joint (c).
study showed that the dorsal system is dominant proximally and the palmar system is important distally. Veins are present at all palmar levels. The radial sides of the IP joint and proximal phalanx and the ulnar side of the web space can be expected to be reliable sources of'veins in replants at these levels.
REFERENCES 1. Lucas GL. The pattern of venous drainage of the digits. J HAND SURG 1984;9A:448. 2. Nystrom A, Schwartz KS, Friden J. Lister GD. Injection-
corrosion-lavage: techniques for study and description of vascular anatomy in the hand. Scand J Plast Reconstr Surg Hand Surg 1990;24:37-41. 3. Goss CM. Gray's anatomy. 28th ed. Philadelphia: Lea & Febiger, 1966;706. 4. Hollingshead H. Anatomy for surgeons. 3rd ed, vol 3. New York: Harper & Row, 1982:532-3. 5. Wilgis S, Kaplan ED. Kaplan's functional and surgical anatomy of the hand. 3rd cd. Philadelphia: J B Lippincott, 1984:216-21.