TREITZ'S ANGLE: ANATOMY AND FUNCTIONS - ANATOMY AND PHYSIOLOGY - 2024

The angle of Treitz, or ligament of Treitz, is a thin, strong structure made up of connective tissue and muscle fibers. It is responsible for raising the duodenum towards the left pillar of the diaphragm. It is also known as the suspensory ligament of the duodenum.

It was described in 1853 by the medical anatomist Václav Treitz. The point where the ligament of Treitz is inserted coincides with the point where the duodenum joins the jejunum. This area is known as the duodenum-jejunal junction.

From Henry Gray's Anatomy - Henry Gray's Anatomy: Descriptive and Applied (Philadelphia: Lea & Febiger, 1913), Public Domain, This ligament is of utmost importance for both specialist surgeons and gastroenterologists, since it is the anatomical structure that defines the end of the duodenum and the beginning of the jejunum.

This means that it determines the site of division between the upper gastrointestinal tract and the lower gastrointestinal tract. In this sense, the ligament of Treitz becomes clinically important when defining whether a pathology or injury originates in the upper or lower digestive system.

Embryology

Around the sixth week of gestation, the midgut begins to form, which is the structure from which the duodenum comes. The central axis of this area is the superior mesenteric artery that divides it into two parts.

The portion that remains above the mesenteric artery is called the duodenum-jejunal loop, and it is the one that ends up forming the duodenum-jejunal ligament in the newborn.

In the fetus, around the seventh week of pregnancy, the intestine rotates on its own axis during its formation. This rotation takes place around the duodenum-jejunal loop, which is a fixed loop within the abdomen.

From the twelfth week of gestation, the intestine begins its final fixation process, finally forming the structure that will be the ligament of Treitz.

Anatomy

The duodenum is the first part of the small intestine. It is responsible for continuing the digestion of the food it receives in the process of emptying the stomach and absorbing vitamins and nutrients. It receives digestive juices from the gallbladder and pancreas.

The duodenum is divided into four angled portions. The fourth portion ends at the duodenum-jejunal junction and its position is well established by the ligament of Treitz, which is responsible for raising it towards the diaphragm.

From Luke Guthmann - Own work, CC BY-SA 3.0, The duodenum, including the duodenum-jejunal angle, is the only fixed structure in the small intestine. The moment it joins the jejunum, the free intestinal loops begin.

The ligament of Treitz measures about 4 cm and extends from the posterior aspect of the duodenum to the left pillar of the diaphragm. It has a position to the left of the midline and its travel is up and back.

As it is a structure that is fixed in the abdomen, it determines that the first loops of the small intestine are also located on the left. Variations in this position are often indicative of disease.

Irrigation

The blood supply of the angle of Treitz comes from the superior mesenteric artery, which is one of the most important branches for the irrigation of the gastrointestinal tract.

From Modified from Henry Gray (1827–1861) - Wikimedia Commons File: Gray533.png, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=56784698 1. Celiac trunk 2. Abdominal aorta 3. Splenic artery 4. Stomach 5. Spleen 6. Pancreas 7. Superior mesenteric artery 8. Duodenum 9. Head of pancreas 10. Portal vein

The superior mesenteric gives duodenal and jejunal branches that join forming an arch from which arteries are born that end up giving their blood supply to the ligament of Treitz.

The vascular arch formed by the duodenal and jejunal branches has many completely normal anatomical variations.

Clinical Importance

The angle of Treitz, or rather its precursor structure, is of fundamental importance in the process of formation of the primitive intestine in the fetus.

The upper part of the digestive system rotates around the duodenum-jejunal loop to find its final position. Later, the duodenal-jejunal loop will give rise to the suspensory ligament of Treitz.

In addition to this, this anatomical structure serves as a guide to roughly know where the duodenum ends and the jejunum begins. This anatomical landmark is of special importance as a point of orientation in abdominal surgeries.

From Illu_small_intestine_català.png: ToNToNi / * derivative work: Ortisa (talk) - Illu_small_intestine_català.png, Public Domain, In surgery, the angle of Treitz is called the “fixed loop” and serves as a guide to determine the location of intestinal tumors or wounds and the length of the intestine.

The angle of Treitz is the structure that separates the upper digestive system from the lower digestive system, which is important to understand diseases such as digestive bleeding.

Knowing if the digestive bleeding is of superior or inferior origin not only completely changes the patient's diagnosis but also his clinical approach and treatment.

Related diseases

Malrotation of the intestine

Malrotation of the intestine is the most common pathology associated with Treitz's angle. It is a pediatric disease and its treatment is always surgical. It occurs when there are problems in the rotation of the intestine during gestation and it cannot reach its final position.

The position of the angle of Treitz, in both radiology and endoscopy, is an accurate indicator that rotation has occurred normally. That is, all patients with intestinal malrotation have a Treitz angle located to the right of the midline.

The symptoms are great abdominal distention and intolerance to the oral route, that is, the patient does not retain food in the stomach. Diagnosis is almost always made at birth or a few days after the infant is born, by radiography of the abdomen.

The position of the angle of Treitz together with the suspicion of the disease from the findings in the paraclinical examinations, guide the physician in its diagnosis.

Mesenteric artery syndrome

Mesenteric artery syndrome is a medical condition that consists of the duodenum being compressed between the mesenteric artery and the aorta due to any anatomical problem that decreases the normal separation angle between these three elements.

When the ligament of Treitz is very short and thick, it can be the cause of this syndrome and it is a challenge to reach the diagnosis, since it does not represent the majority of cases.

The symptoms that the patient presents are those typical of an upper digestive obstruction, that is, vomiting, diffuse abdominal pain or a sensation of gas, among others. Likewise, the signs on the abdominal X-ray are typical of upper digestive obstructions.

By James Heilman, MD - Own work, CC BY-SA 3.0, Treatment is surgical and consists of freeing the duodenum by cutting the Treitz ligament so that it can regain its normal function.

References

1. Jit, I; Grewal, SS (1977). The suspensory muscle of the duodenum and its nerve supply. Journal of anatomy. Taken from: ncbi.nlm.nih.gov
2. Seuk Ky, Kim; Cho, CD; Wojtowycz, Andrij R. (2008). The ligament of Treitz (the suspensory ligament of the Duodenum): anatomic and radiographic correlation. Abdominal imaging. Vol. 33, 4
3. Meyers, MA (1995). Treitz redux: the ligament of Treitz revisited. Taken from: ncbi.nlm.nih.gov
4. Perdenera, E. (2006) Embryology in the clinic: medical cases. Panamerican Medical Publishing House.
5. Mena GA; Bellora, A. (2015). Swirl sign: intestinal malrotation and midgut volvulus. Argentine journal of radiology. Vol. 79, No. 2
6. Mesa Avella, Diego; Corrales, Juan Carlos; Ceciliano, Norma. (1999). Intestinal malrotation: comparative study between clinical, radiological and intraoperative findings. Acta Pediátrica Costarricenses. Taken from: ssa.cr
7. Suhani, Aggarwal, L; Ali, S; Jhaketiya, A; Thomas, S. (2014). Short and hypertrophic ligament of Treitz: a rare cause of superior mesentric artery syndrome. Journal of clinical and diagnostic research: JCDR. Taken from: ncbi.nlm.nih.gov