Arterial supply to the human rectum.

Area of Science:

• Anatomy
• Vascular Surgery
• Colorectal Surgery

Background:

• Understanding the arterial supply of the rectum is crucial for surgical procedures.
• Variations in rectal arterial anatomy can impact surgical outcomes and complications.

Purpose of the Study:

• To detail the arterial anatomy of the human rectum.
• To identify the primary and variant arterial sources supplying the rectum.
• To investigate the presence and extent of anastomoses within the rectal arterial system.

Main Methods:

• Dissection of 32 formalin-fixed autopsy specimens.
• Radiography of 5 specimens after arterial injection with radio-opaque material.
• Preparation of plastic casts of the arterial bed from 5 specimens.

Main Results:

• The superior rectal artery is the main source of rectal blood supply, branching into recto-sigmoid, upper rectal, and two terminal branches.
• Terminal branches of the superior rectal artery supply the lower two-thirds of the rectum.
• The middle rectal artery, present in 12% of specimens, supplies a limited rectal area and its presence correlates with superior rectal artery diameter.
• The inferior rectal artery supplies the anal canal below the levator ani.
• Intramural anastomoses exist between the superior and inferior rectal arteries, but extramural anastomoses between main rectal arteries were not observed.

Conclusions:

• The superior rectal artery is the predominant artery supplying the rectum.
• The middle rectal artery is an occasional variant, and its presence can be predicted.
• Intramural vascular connections within the rectal wall are present, primarily between the superior and inferior rectal arteries.