CHAPTER 4
Duodenum and Small Bowel
INTRODUCTION
Routine endoscopy is primarily limited to examination of the duodenal bulb and second portion of the duodenum, with an occasional glimpse of the third portion. With the availability of small-bowel enteroscopes and more recently of capsule technology, the entire small bowel can be visualized. The duodenal bulb appears as a small, round cavity with a finely granular appearance. At the superior duodenal angle, which marks the junction of the first and second portions, Kerckring’s valves, or the circular folds, become visible. In contrast with the bulb, the mucosa assumes a more granular and frequently whitish appearance. The ampulla occasionally may be identified on the medial wall, especially when prominent. The intimacy of the pancreas and biliary system to the duodenum may be reflected by endoscopic lesions resulting from diseases of pancreaticobiliary tree.
Duodenal disease is generally limited to the bulb, where inflammatory disorders, erosions, and ulcers are found. Neoplasms typically reside in the distal duodenum, jejunum, or ileum, and thus remain endoscopically hidden with routine endoscopy. If required, examination of the distal duodenum can be accomplished with a pediatric colonoscope or dedicated enteroscope. The anterior–posterior relationships in the duodenal bulb are important to understand, particularly when characterizing ulcer disease in the setting of gastrointestinal hemorrhage. The terminal ileum can be evaluated at the time of colonoscopy in most cases. In some situations, intubation of the terminal ileum should be routine; for example, when evaluating for Crohn’s disease or when finding fresh blood in the cecum in a patient with gastrointestinal bleeding. The identification of small-bowel lesions by capsule endoscopy may now be amenable to endoscopic therapy with the double-balloon endoscope.
Figure 4.1 NORMAL DUODENUM
A, Upper gastrointestinal barium series demonstrates a normal-appearing duodenal bulb, with barium in the second duodenum (C sweep) and distal duodenum. The pylorus is seen en face.
B, The distal duodenum and proximal jejunum have a characteristic feathery appearance. The distal duodenum and proximal jejunum are seen coursing behind the antrum.
Figure 4.2 NORMAL DUODENAL BULB
A, The mucosa is not smooth but has a subtle textured appearance. The superior duodenal angle marks the junction between the distal duodenal bulb and the second duodenum. Vascularity can usually be appreciated. B, The vascular pattern is more pronounced. No real angle exists between the bulb and the second portion of the duodenum in this patient. The circular folds of the second duodenum are shown.
Figure 4.3 SECOND DUODENUM
A, The second duodenum is characterized by circular folds termed valvulae conniventes or Kerckring’s valves. The mucosa has a granular appearance. The junction of the second and third duodenum (inferior duodenal angle) is in the distance. B, The mucosa may have a frosty white appearance.
C, The duodenal mucosa is characterized by slender villi composed of goblet cells.
Appearance as shown by magnification endoscopy (D) and narrow band (E) imaging.
Figure 4.4 MAJOR AND MINOR PAPILLAE
A, The major papilla is seen on the medial wall of the mid-second duodenum; the minor papilla is shown proximally and in a superior position. B1, Small, polypoid-like lesion on the medial wall in the mid-second duodenum. B2, The papilla can be seen in a more en face view. The ampullary orifice is visible, and just distal is the longitudinal fold. B3, The major papilla is small and well seen with the forward viewing endoscope. (Drawing) Folds lead to the papilla.
Figure 4.5 JEJUNUM
The jejunum is characterized by thinner but more frequent circular folds than in the duodenum, and the mucosa is smoother.
Figure 4.6 TERMINAL ILEUM
A, Reflux of barium on enema examination. B, Small-bowel follow-through. Barium also outlines the cecum. C, The mucosa has a finely granular appearance, and lymphoid follicles are present. D1, The mucosa has a fine, granular appearance. As visualized underwater, the villi can now be appreciated (D2). E, Prominent villi are noted in this patient.
Figure 4.7 LYMPHOID HYPERPLASIA
A, Marked nodularity of the terminal ileum, as shown by reflux of barium during barium enema examination. B, Multiple well-circumscribed nodules. Lymphoid hyperplasia in the distal terminal ileum is a normal finding, frequent in younger persons.
Figure 4.8 EROSIVE DUODENITIS
Multiple erosions in the duodenal bulb.
Figure 4.9 EROSIVE DUODENITIS
A, Marked nodularity of duodenal bulb. B, Severe edema, subepithelial hemorrhage, and multiple erosions. A portion of an active crater is present.
Figure 4.10 HEMORRHAGIC DUODENITIS
Patchy subepithelial hemorrhage in the distal duodenal bulb.
Figure 4.11 DUODENAL ULCER
A duodenal ulcer is shown anteroinferiorly (A). Methylene blue has been placed in the bulb with the patient still in the left lateral decubitus position (B).
If the patient is moved to the supine position, fluid collects posteriorly, confirming the position in the bulb (C). The posterior portion of the antrum is demarcated by methylene blue (D).
Figure 4.12 DUODENAL ULCER
A, Anterior clean-based duodenal ulcer. The duodenal folds are markedly edematous at the superior duodenal angle. A speckled pattern is on the gastric body, suggesting gastritis (inset, top). The antrum appears normal endoscopically (inset, bottom). Helicobacter pylori chronic active gastritis was histologically identified in both the body and the antral mucosa.
B, Deep anterior ulcer with multiple black spots in the ulcer base, suggesting recent bleeding. The ulcer margins are edematous and hemorrhagic. The antrum and peripyloric area show mild erythema and subepithelial hemorrhage, especially around the pylorus, suggesting gastritis (inset). H. pylori chronic active gastritis was found on antral biopsy.
Figure 4.13 DUODENAL ULCER
A, A persistent collection of barium with radiating folds in the duodenal bulb, highly suggestive of an ulcer.
B, Posterior duodenal ulcer with a clean base. There is marked edema of the bulb, with folds radiating from the ulcer. Subepithelial hemorrhage is surrounding the ulcer, as well as in the remainder of the bulb. A small ulcerative lesion is also shown anteriorly.
Figure 4.14 DUODENAL ULCER
Well-circumscribed ulcer with yellow exudate resembling a fried egg.
Figure 4.15 DUODENAL ULCER
Large duodenal ulcer with surrounding edema projecting into the duodenal bulb. The second duodenum is normal.
Figure 4.16 DUODENAL ULCER
Small, clean-based ulcer surrounded by prominent folds and diffuse subepithelial hemorrhage.
Figure 4.17 DUODENAL ULCER WITH SCARRING
Duodenal ulcer with several lesions and marked retraction resulting from prior disease.
Figure 4.18 ANTERIOR SUTURE WITH SMALL ULCER
Suture at the site of a prior oversew of duodenal ulcer hemorrhage. Small ulceration is seen at the base of the suture material.
Figure 4.19 DUODENAL ULCER WITH DEFORMITY
A, Markedly abnormal duodenal bulb with active ulceration and pseudodiverticula. B, Forceps were placed in the slitlike opening demonstrating a mucosal bridge.
Figure 4.20 MALIGNANT DUODENAL ULCER
A, Edematous fold posteriorly at the junction of the first and second duodenum. There is mild narrowing and associated ulceration anteriorly. B, The ulceration is surrounded by edematous duodenal tissue. C, The depth of the lesion is evident. Biopsy results proved adenocarcinoma, and this patient had a hilar mass (cholangiocarcinoma).
Differential Diagnosis
Duodenal Ulcer (Figure 4.20)
Benign duodenal ulcer
Extrinsic neoplasm (cholangiocarcinoma, pancreatic carcinoma)
Periduodenal inflammatory process (e.g., pancreatitis)
Figure 4.21 DUODENAL DEFORMITY MIMICKING ULCER
A, Collection of barium in the duodenal bulb with radiating folds, suggestive of an active ulcer crater. There is marked edema of the folds in the second duodenum, suggesting duodenitis. B, The collection of barium represents an old healed ulceration. The duodenal bulb is markedly distorted, with multiple erosions and edema. In a patient with prior ulcer disease, healed craters, and secondary pseudodiverticula, active ulcer craters may be difficult to distinguish radiographically from inactive healed disease.
Figure 4.22 DUODENAL DEFORMITY MIMICKING POLYP
A, Filling defect in duodenal bulb mimicking a polyp.
B, The pylorus is patulous (B1); the bulb is edematous, with an active crater (B2, B3). Marked deformity and edema are present at the junction of the first and second portion of the duodenum (B4).
Figure 4.23 DOUBLE PYLORUS
A, Two openings at the pylorus separated by a mucosal bridge. B, The anterior opening is now more apparent when cannulated with a stiff wire. C, Upper gastrointestinal (UGI) series shows the two pathways to the duodenal bulb.
Figure 4.24 PYLORIC CHANNEL ULCER
A, The pylorus is seen with a clean-based ulcer posteriorly and a smaller ulcer anteriorly. There is associated subepithelial hemorrhage in the channel. A normal-appearing duodenal bulb and superior duodenal angle are seen in the distance.
Figure 4.24 PYLORIC CHANNEL ULCER
B, Mild narrowing of the pylorus with erythema and shallow posterior ulcer. C, Patulous pylorus with shallow ulcer both anteriorly and posteriorly.
Figure 4.25 DUODENAL ULCER CAUSING GASTRIC OUTLET OBSTRUCTION
A, Markedly dilated, fluid-filled stomach, with barium seen in the distal esophagus and puddling in the gastric body. The gastric air bubble is pronounced. A succussion splash was present on physical examination. B, Deformity of the peripyloric area and bulb.
Figure 4.25 DUODENAL ULCER CAUSING GASTRIC OUTLET OBSTRUCTION
C, Deformity of bulb with active ulcer and edema, causing a mass effect on the proximal second duodenum.
D, The pylorus is absent. A large pseudodiverticulum is shown anteriorly (D1-D3). Edema and narrowing are present with further advancement of the endoscope (D4).
Figure 4.25 DUODENAL ULCER CAUSING GASTRIC OUTLET OBSTRUCTION
E, An ulcer is seen posteriorly (E1-E3). The circumferential process ends abruptly at the superior duodenal angle (E4).
Figure 4.26 ULCER IN DESCENDING DUODENUM
Large hemicircumferential bile-stained ulcer in the mid-second duodenum. The lesion was caused by nonsteroidal antiinflammatory drug use.
Figure 4.27 ZOLLINGER-ELLISON SYNDROME
A, Edema and erythema at the junction of first and second duodenum associated with a small posterior ulcer. B, Giant ulcer in the second duodenum. C, Multiple ulcers in the mid-second duodenum. D, This patient also had severe erosive esophagitis. The association of esophagitis with ulcers in the second duodenum should raise suspicion for Zollinger-Ellison syndrome.
Figure 4.28 DUODENAL ULCER WITH FLAT RED SPOT
Large ulcer with flat red spot.
Figure 4.29 GIANT DUODENAL ULCER WITH RAISED SPOT
Note the depth of the lesion with the surrounding ulcer rim. A raised black spot in the center of the ulcer indicates the point of bleeding.
Figure 4.30 DUODENAL ULCER WITH BLACK BASE
A, Large posterior ulcer with heaped-up margins and adherent heme. B, Well-circumscribed posterior ulcer partially covered by old blood. C, Anterior duodenal ulcer with black base. Note the nearby small, clean-based ulcer.
Figure 4.31 DUODENAL ULCER WITH CLOT
A1, Anterior ulcer with protruding adherent clot. A2, Epinephrine is injected into the base of the clot with bleeding precipitated. A3, The clot is removed with biopsy forceps. Note the ischemic appearance of the duodenum resulting from the epinephrine injection. A4, Oozing was seen from fleshy material at the base of the clot representing a visible vessel. A5, Thermal therapy was applied to the bleeding area, resulting in black eschar with depth and hemostasis achieved.
Figure 4.31 DUODENAL ULCER WITH CLOT
B, Deep serpiginous ulcer with adherent clot proximally and flat black spot distally. C, Adherent clot to a posterior ulcer. D1, Shallow anterior ulcer with small adherent clot. D2, 7-French heater probe applied to the clot. D3, Depression with black eschar after successful ablation of the area of clot.
E1, Large ulcer with central adherent clot. E2, The clot was manipulated with the thermal probe, resulting in dislodgement and exposure of fleshy material, presumably visible vessel. E3, Dilute epinephrine is injected into the base of the fleshy material. Note the dislodged clot in the distance. E4, After injection, there is marked ischemia of the anterior duodenum.
Figure 4.32 MASS-LIKE DUODENAL ULCER WITH CLOT
A, Mass effect in the posterior duodenum with central ulceration. B, Close-up of the ulcerated area demonstrates an opening covered with clot. C, With clot removed, a cavity is evident.
D, More distally, circumferential ulcer is seen with normal duodenum in the distance. E, Marked circumferential thickening of the duodenum resembling a mass lesion. Air is seen in the lumen and in the thickened wall. Surgery confirmed a benign duodenal ulcer.
Figure 4.33 MALIGNANT DUODENAL ULCER WITH BLEEDING VISIBLE VESSEL
A, Large ulcer in the anterior wall of the duodenal bulb. Note the mass effect in the duodenum and the lack of well-defined edges to the ulcer. There is a central fresh blood clot with active oozing from underneath. B, Thermal therapy was applied to the area, resulting in eschar and depression. Subsequent biopsy results showed adenocarcinoma.
Figure 4.34 DUODENAL ULCER WITH VISIBLE VESSEL
A, Large ulcer with central protrusion and fresh bleeding. The protrusion was seen to pulsate (an artery), and no endoscopic therapy was thus performed. B, Small ulcer with fleshy visible vessel at the proximal margin with a small adherent red clot. C1, Red nipple extending from a small anterior duodenal ulcer. C2, Dilute epinephrine is injected just inferior to the nipple. C3, Note the marked blanching after epinephrine injection. C4, A thermal probe is approaching the vessel. C5, Black eschar and cavitation resulting from thermal therapy. D1, Visible vessel in a small duodenal ulcer with active arterial bleeding. D2, Thermal therapy is applied directly to the bleeding point. D3, Black eschar at the site of thermal therapy and resultant hemostasis.
Figure 4.35 DUODENAL ULCER WITH VISIBLE VESSEL AND ARTERIAL BLEEDING
A, Large anterior duodenal ulcer with fleshy nonbleeding visible vessel. B, With observation, active arterial bleeding began. C, Appearance of the ulcer after thermal therapy.
Figure 4.36 DUODENAL ULCERS WITH MULTIPLE STIGMATA
Two ulcers in the bulb with associated pseudodiverticulum. The anteroinferior ulcer has a white nipple-like projection, whereas the superior ulcer has a large, flat black area.
Figure 4.37 BLEEDING ULCER IN SECOND DUODENUM
A, Fresh blood and active bleeding from a clot in the second duodenum. Because of the position, a forward viewing endoscope could not adequately visualize the area for endoscopic therapy. B, Bleeding area as seen with side viewing duodenoscope. An en face view was now possible. C, With vigorous washing, a focal area of bleeding was seen and dilute epinephrine injected with a sclerotherapy needle. D, After epinephrine therapy, a fleshy vessel was identified. The 10-French thermal probe is in position. Multiple pulses were applied, resulting in hemostasis and a black eschar. E, Note bile flowing from the major papilla just superior to the lesion.
Figure 4.38 DUODENAL ULCER PERFORATION
Large duodenal ulcer with apparent opening. Surgery confirmed a perforated anterior ulcer.
Figure 4.39 COILS IN DUODENAL WALL FROM PRIOR EMBOLIZATION
A, B, Round coils at site of prior bleeding ulcer.
Figure 4.40 CROHN’S DISEASE
A1, Irregular ulceration at the junction of first and second duodenum. A2, Close-up shows the serpiginous nature of the ulcer. B1, B2, Serpiginous ulceration with nodularity in the third duodenum with some narrowing. B3, More distally, a stricture is shown. B4, Balloon dilatation of the stricture.
B5, B6, UGI series with a small-bowel follow-through shows multiple strictures and distal ileal disease confirming the diagnosis of Crohn’s disease.
Figure 4.41 JEJUNAL CROHN’S DISEASE
Ulcerated stricture in the proximal jejunum found by push enteroscopy. (Courtesy F. Perez-Roldan, MD, and P. Gonzalez-Carro, MD, Alcazar de San Juan, Spain.)
Figure 4.42 ISCHEMIA
Serpiginous ulceration throughout the second duodenum.
Figure 4.43 INFARCTION
A, Thick exudate covers the duodenum. B1, B2, When the exudate is débrided, the underlying mucosa is black and necrotic.
Figure 4.44 VASCULAR ECTASIA
A, Air has been withdrawn from the duodenal bulb to bring the ectasia closer, documenting the lack of depth and the characteristic frondlike appearance. B1, Solitary ectasia in the second duodenum. B2,
