The intramuscular arterial anatomy of the long head of biceps femoris muscle.

We have previously shown that the neurovascular anatomy and length of the long head of biceps femoris (LHBF) is suitable for its possible use in the creation of a dynamic perianal myoplasty to restore faecal continence. If intramuscular arterioarterial anastomoses exist between a muscle's vascular pedicles then the delay procedure, i.e. ligating the vascular pedicles to the transposed section of the muscle, 4-6 wk before transposition, can be used to improve blood flow to the distal part of the transposed muscle. The intramuscular arterial anatomy of 20 biceps femoris muscles was shown by dissection (14) or radiographically (6). The mean entry point of the upper major vascular pedicle to the LHBF was 12 cm (S.D. 3.3) and the mean length of the LHBF was 36.8 cm (S.D. 1.8). Therefore the ratio between upper major vascular pedicle entry point and muscle length in 95% of specimens was 0.33 (0.2). In the present study intramuscular arterioarterial anastomoses were found between the arterial pedicles to the nontransposed and transposed sections of the LHBF and between the long and short heads of this muscle. Using the delay procedure would therefore theoretically allow the intramuscular arterioarterial anastomoses between the arterial pedicle to the nontransposed and transposed sections of the LHBF to open up enhancing blood flow to the distal part of the myoplasty.