Endoscopic signs of duodenal diverticula

Duodenal diverticula are blind-ending protrusions of the duodenal wall. Most often, they involve all layers of the intestinal wall. The main factor in the formation of diverticula is duodenal hypertension.

Contributing factors: weakness of the wall at the entry points of the vessels (along the medial wall), inclusions of fatty tissue, heterotopia of the pancreatic tissue, developmental defects. In terms of frequency, they occupy second place after diverticula of the colon. They are often combined with diverticula of the small and large intestines, and sometimes the entire digestive tract.

Classification.

1. a) pulsation, b) traction.
2. a) true, b) false.
3. a) congenital, b) acquired.

True diverticula are most often located along the medial wall (97%), mainly in the middle third of the descending part of the duodenum in close proximity to the head of the pancreas and the common bile duct (“embedded” in the pancreatic tissue). Such preferential localization of diverticula is explained by the weakness of the intestinal wall in this area due to the entry of vessels. The second most common site of localization is the lower horizontal part. Multiple (2-4) diverticula are often observed.

The sizes of diverticula vary and are difficult to determine because they change against the background of peristalsis. The shape is often oval or round, less often they are cylindrical or funnel-shaped. The mucous membrane of diverticula is pale pink with a pronounced vascular pattern, the surrounding mucous membrane is unchanged. The lumen of the isthmus is narrow, which causes stagnation of intestinal contents in the diverticulum and the development of inflammatory changes in the mucous membrane (diverticulitis). The entrance to the diverticulum is not always freely detected. The study is complicated by the folding of the mucous membrane of the duodenum, rigidity of the wall at the base of the diverticulum due to the inflammatory reaction and increased peristalsis. Clinical manifestations only in case of complications.

In addition to true diverticula, endoscopic examination may reveal false diverticula located in the duodenal bulb near the pyloric sphincter. These are traction diverticula formed as a result of bulb deformation after scarring of a previously existing ulcer. Their shape may vary.

Differential diagnosis of diverticula and pseudodiverticula

Diverticulum	Pseudodiverticulum
1. Most often in the descending part along the medial wall 2. There is a neck 3. Round or oval shape 4. Acidity is reduced or normal	1. Most often in the bulb along the front wall 2. No neck 3. The shape is irregular or cylindrical 4. Acidity is increased, there may be erosive-ulcerative duodenitis

Endoscopy determines the localization, shape, size, condition of the mucosa, location in relation to the BDS: the BDS can be located peridiverticularly (on the edge of the diverticulum) or intradiverticularly (inside the diverticulum). When the BDS is located at the bottom of the diverticulum, a longitudinal fold is visible, going into the diverticulum, and the BDS is not visible. In case of diverticulitis, diagnosis is difficult, a full examination is possible only after the edema has subsided.

Complications of diverticulamay arise due to pathological changes within the diverticulum itself (diverticulitis, ulceration, bleeding) or as a result of its pressure on the surrounding organs (torsion of the diverticulum isthmus with strangulation, perforation, involvement of adjacent organs in the inflammatory process, malignant degeneration, deformation and stenosis). Endoscopically, it is necessary to be able to differentiate diverticulitis from a penetrating ulcer: with a penetrating ulcer, fibrin deposits are determined at the bottom of the defect, its shape is funnel-shaped, there is an inflammatory ridge, and the folds converge toward the defect. With diverticulitis, hyperemia, edema, mucus, and pus are noted.

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