| Suspensory muscle of duodenum | |
|---|---|
 Theduodenum. The suspensory muscle of the duodenum attaches to theduodenojejunal flexure, shown. | |
 Theduodenum andjejunum depictedin situ. The suspensory muscle of the duodenum connectsposteriorly to the duodenojejunal flexure, behind the pancreas, shown. | |
| Details | |
| System | Gastrointestinal |
| Origin | Connective tissue surroundingceliac artery andsuperior mesenteric artery |
| Insertion | Third and fourth-parts ofduodenum,duodenojejunal flexure |
| Nerve | Celiac plexus,Superior mesenteric plexus |
| Actions | Facilitates movement of food; embryological role in fixating jejunum during gut rotation |
| Identifiers | |
| Latin | musculus suspensorius duodeni, ligamentum suspensorium duodeni |
| TA98 | A05.6.02.011 |
| TA2 | 3781 |
| FMA | 20509 |
| Anatomical terms of muscle | |
Thesuspensory muscle of duodenum (also known assuspensory ligament of duodenum,Treitz's muscle orligament of Treitz[1]) is a thinmuscle connecting the junction between theduodenum andjejunum (thesmall intestine's first and second parts, respectively), as well as theduodenojejunal flexure toconnective tissue surrounding thesuperior mesenteric andcoeliac arteries. The suspensory muscle most often connects to both the third and fourth parts of the duodenum, as well as the duodenojejunal flexure, although the attachment is quite variable.
The suspensory muscle marks the formal division between the duodenum and the jejunum. This division is used to mark the difference between theupper and lower gastrointestinal tracts, which is relevant inclinical medicine as it may determine the source of gastrointestinal bleeding.
The suspensory muscle is derived frommesoderm and plays a role in theembryological rotation of the gut, by offering a point of fixation for the rotating gut. It is also thought to help digestion by widening the angle of the duodenojejunal flexure.Superior mesenteric artery syndrome is a rare abnormality caused by a congenitally short suspensory muscle.
Theduodenum and thejejunum are the first and second parts of thesmall intestine, respectively. The suspensory muscle of the duodenum marks their formal division.[2][3] The suspensory muscle arises from theright crus of thediaphragm as it passes around theesophagus, continues asconnective tissue around the stems of theceliac artery andsuperior mesenteric artery, passes behind thepancreas, and enters the upper part of themesentery, inserting into the junction between the duodenum and jejunum, theduodenojejunal flexure.[4] Here, the muscles are continuous with the muscular layers of the duodenum.[1][2]
Considerableanatomic variation exists, in terms of length and point of attachment.[5] Despite the classical description, the muscle only solely attaches to the duodenojejunal flexure in about 8% of people; it is far more common, 40 to 60% of the time to attach additionally to the third and fourth parts of the duodenum; and 20 to 30% of the time it only attaches to the third and fourth parts. Moreover, separate multiple attachments are not that uncommon.[1]
According to some authors, who use the original description by Treitz, the muscle may be divided into two sections: a ligamentous portion attaching theright crus of diaphragm to the connective tissue surrounding thecoeliac artery and superior mesenteric artery; and a lower muscular portion from the connective tissue attaching to the duodenum. The superior portion is also described as theHilfsmuskel.[4][5] These two parts are now considered anatomically distinct, with thesuspensory muscle referring solely to the lower structure attaching at the duodenum.[1][5]
The ligament contains a slender band of skeletal muscle from the diaphragm and a fibromuscular band of smooth muscle from the horizontal and ascending parts of the duodenum. When it contracts, by virtue of connections to the third and fourth parts of the duodenum, the suspensory muscle of the duodenum widens the angle of the duodenojejunal flexure, allowing movement of the intestinal contents.[1][6]
Embryologically, the suspensory muscle of the duodenum is derived frommesoderm. It plays an important role in the embryological rotation of the small intestine as the superior retention band.[1][4]
This ligament is an importantanatomical landmark of the duodenojejunal flexure, separating theupper and lower gastrointestinal tracts. For example,bloody vomit ormelena, black tarry stools, usually indicate a gastrointestinal bleed from a location in the upper gastrointestinal tract. In contrast,hematochezia, bright red blood or clots in the stool, usually indicates gastrointestinal bleeding from the lower part of the gastrointestinal tract.[7] It is an especially important landmark to note when looking at the bowel for the presence ofmalrotation of the gut, a syndrome often suspected in young children when they have episodes of recurrent vomiting. Visualising a normal location of the ligament of Treitz in radiological images is critical in ruling out malrotation of the gut in a child; it is abnormally located when malrotation is present.[5]
During aWhipple's procedure, commonly used to treatpancreatic cancer by removing thepancreas, duodenum, and part of the jejunum, the ligament of Treitz is separated from the duodenum and preserved. When the remaining jejunum isanastamosed with thepylorus of thestomach, it may be passed through the ligament.[8]
Superior mesenteric artery syndrome (SMA) is an extremely rare life-threatening condition that can either be congenital and chronic, or induced and acute. SMA Syndrome is characterised by compression of the duodenum between theabdominal aorta and the superior mesenteric artery, and may—when congenital—result from a short suspensory muscle. One surgical treatment isStrong's operation, which involves cutting the suspensory muscle, though this is not often carried out.[9]
The suspensory muscle of the duodenum was first named in 1853 byVáclav Treitz, as themusculus suspensorius duodeni (in Latin), and described as consisting of a lower muscular portion with a broad base, and an upper tendinous portion blending with connective tissue around the origins of the superior mesenteric and coeliac arteries. It is commonly termed theligament of Treitz byclinicians and as thesuspensory muscle of the duodenum byanatomists. It has also been likened to "apolar ice cap ... a structure that many refer to but few have seen."[1]
