The superior rectal artery and its branching pattern with regard to its clinical influence on ligation techniques for internal hemorrhoids.

Background: The hemorrhoidal artery ligation has been used for submucosal ligation of hemorrhoidal arteries by means of an ultrasonographic transducer since 1995. The success of this technique depends on the submucosal course of these arteries. Our investigation deals with branches of the superior rectal artery which pierce the rectal wall where they cannot be reached by this method.
Methods: The branching patterns were investigated by means of 5 macroscopic preparations of adult pelves, histological section series of 35 fetal and 3 adult pelves impregnated in epoxy-resin, and transperineal color Doppler ultrasound of 7 proctologic patients and 28 volunteers.
Results: Additional branches of the superior rectal artery coursing in outer layers of the rectal wall were shown entering the rectal wall just above the levator ani muscle to supply the internal hemorrhoidal plexus (corpus cavernosum recti).
Conclusions: The terminal course of the branches of the superior rectal artery is not only applied to the rectal submucosa. We have shown that additional branches may be detected by ultrasonography and should be taken into account by the operating surgeon.