Hepatic Flexure

Overview

The hepatic flexure, also known as the right colic flexure, is the sharp bend between the ascending colon and the transverse colon of the large intestine. It lies in close proximity to the liver, hence the name "hepatic." This anatomical region plays a passive but important role in directing the flow of fecal material as it moves through the colon.

Location

The hepatic flexure is located in the right upper quadrant of the abdomen. It:

• Marks the junction between the ascending colon and the transverse colon

• Lies just inferior to the inferior surface of the right lobe of the liver

• Is adjacent to the gallbladder anteriorly and the right kidney posteriorly

It is less mobile than the transverse colon but more mobile than the ascending colon, as it is partially suspended by the peritoneum.

Structure

Structurally, the hepatic flexure is composed of the typical layers of the large intestinal wall:

• Mucosa: Simple columnar epithelium with goblet cells for mucus secretion

• Submucosa: Contains blood vessels, lymphatics, and connective tissue

• Muscularis externa: Composed of inner circular and outer longitudinal layers, the latter forming taeniae coli

• Serosa: Visceral peritoneum partially covers the hepatic flexure, giving it limited mobility

This segment of the colon may also show visible haustra (sacculations) and epiploic appendages (fat-filled pouches).

Function

While the hepatic flexure does not perform an active physiological function, it contributes to the following:

• Directional change: Redirects intestinal contents from a vertical to a horizontal path as they move from the ascending to the transverse colon

• Transit delay: The angle can cause a temporary slowing of colonic content movement, assisting in water and electrolyte absorption

Physiological Role(s)

The hepatic flexure supports digestive physiology indirectly by:

• Contributing to colonic segmentation: Its bend contributes to segmentation of the large intestine, enhancing control of material movement

• Allowing efficient absorption: Slowing the passage of chyme at the flexure enhances reabsorption of fluids and electrolytes

• Supporting peristalsis: The musculature in the region participates in colonic peristaltic contractions

Its anatomical position near key organs (liver, kidney, gallbladder) also makes it significant in surgical navigation and radiological interpretation.

Clinical Significance

The hepatic flexure is clinically relevant in several conditions:

• Hepatic flexure syndrome: A poorly defined condition involving gas trapping and discomfort in the right upper quadrant, sometimes mistaken for biliary or gastric disorders

• Colonic tumors: The hepatic flexure is a common site for right-sided colon cancers, which may present with anemia, weight loss, or occult bleeding

• Obstruction: Masses, volvulus, or inflammation can cause partial or complete blockage at the flexure, leading to symptoms like abdominal distension and pain

• Crohn’s disease and colitis: Inflammatory bowel diseases may involve this region and result in wall thickening, strictures, or fistulas

• Surgical relevance: During right hemicolectomy or colonic mobilization, knowledge of hepatic flexure anatomy is essential

• Imaging interpretation: On CT or barium enema, the hepatic flexure must be distinguished from neighboring structures such as the liver and duodenum

Thorough understanding of the hepatic flexure is important in the diagnosis of abdominal pathology and in planning surgical or radiologic interventions involving the right colon.