Diseases of the Small Bowel

Compression of the esophagus:

Arteria lusoria: The esophagus can also be compressed from the outside (Fig. 9.21a). A relatively frequent—and congenital—cause is an aberrant right subclavian artery in "dysphagia lusoria".

Osteochondrosis of the cervical spine: Ventral degenerative spondylophytes of the cervical spine may impinge on the esophagus from dorsally and lead to dysphagia as well (Fig. 9.21b).

In older patients there frequently is an extrinsinc impression of the esophagus by an ectatic aortic arch, sometimes also compression of the distal esophagus by an ectatic and tortuous thoracic aorta, which may cause swallowing problems (dysphagia aortica).

• Diagnosis: Paul decides that this eccentric stenosis of the middle segment of the esophagus must be due to a process that extends through the mucosa. Until proven otherwise, this is a carcinoma, most likely a squamous cell carcinoma. The biopsy taken during a fiberendoscopy on the next day confirms that diagnosis.

Any space-occupying lesion and any stenosis of the esophagus requires histological work-up.

Checklist:

Diseases of the Small Bowel

• Are symptoms related to ingestion of any specific food items?

• Is there diarrhea or weight loss?

• Is an abdominal tumor palpable?

• Has there been abdominal surgery?

Intestine on Strike

Josephine Slimline (16) has been a puzzle to her family and her general practitioner. She complains about diarrhea and abdominal cramps. Her weight has remained constant for the last two years. Her primary care physician has now asked for a double contrast examination of the small bowel, also called enteroclysis, to get to the root of the problem. Dr. Llewellyn has made a deal with Paul: Paul may introduce the tube into the jejunum under close supervision, but the remainder of the examination will be done by Llewellyn himself. After all—Josephine is only 16 years old and the exposure dose of this study to the radiosensitive female go-nads and the bone marrow is relatively high. Especially in patients of reproductive age, the procedure should be done by an experienced radiologist rapidly and efficiently. Paul even succeeds in getting Ms. Slimline to laugh on the examination table. She has closely followed the instructions for the preparation for examination (see below).

| Double Contrast Enema of the Small Bowel: Normal Findings

Small Bowel Double Contrast

Fig. 9.22 This is a normal small-bowel pattern in a double contrast examination. In the jejunum (a) you find less than one mucosal fold per centimeter; in the ileum (b) there are more than two mucosal folds per centimeter. Note that the distance between the bowel loops is of major diagnostic significance because it indicates the thickness of the bowel wall.

Fig. 9.22 This is a normal small-bowel pattern in a double contrast examination. In the jejunum (a) you find less than one mucosal fold per centimeter; in the ileum (b) there are more than two mucosal folds per centimeter. Note that the distance between the bowel loops is of major diagnostic significance because it indicates the thickness of the bowel wall.

A correct preparation by the patient is crucial for a small-bowel examination.

What Is a Perfect Patient Preparation for Enteroclysis of the Small Bowel?

On the day before the examination the patient should consume nothing but clear liquid foods (clear soups, coffee, tea, clear juices). High-fiber foods, vegetables, fruits, rice, meat, or milk should be avoided in particular. A laxative may also be taken on the day before the examination.

On the eve of the examination (after 10 p.m.) and on the day of the examination nothing may enter the mouth: no smoking, no tooth brushing, no oral medication, no drinking, no eating.

I The Case of Josephine Slimline

I The Case of Josephine Slimline

Small Bowel Enema Tubes

Fig. 9.23 Analyze the relevant radiograph from Ms. Slimline's small-bowel examination.

The experienced x-ray tech Mrs. Fairweather lends Paul a hand as he introduces the cooled tube via a nostril after having lubricated it with a lidocaine gel (also called xylo-caine or lignocaine). Paul has also sprayed lidocaine solution into the patient's nose and throat. Josephine turns out to be a brave and calm patient and breathes regularly in a controlled way. As the tube is far enough in to reach the tongue base, Paul asks Josephine to swallow a few times and he is in luck: during this maneuver the tube can easily be advanced. A short fluoroscopy confirms the position of the tube tip inside the stomach. He pushes the tube into the region of the pylorus and withdraws the guide-wire just a little. He asks Josephine to position herself on her right side. After a little while the soft tip of the tube slides through the pylorus into the duodenum. Paul advances the tube some more until the tip is positioned just distal to the ligament of Treitz in the jejunum. After withdrawing the guide-wire, he injects a little thin barium solution through the tube to confirm the position of the tip: it is right where it is supposed to be. Mrs. Fairweather gives him a big smile. Dr. Llewellyn seems to be satisfied as well: "We have seen worse than that!" he nods to Paul before he walks over to Ms. Slimline to start the examination itself. Rapidly a special barium suspension and then a preparation of methyl-cellulose are infused via the tube. All small-bowel loops are expanded and evaluated (Fig. 9.22). While watching the examination and during the subsequent review of the exposed radiographs, one segment grabs Paul's attention (Fig. 9.23).

• What is Your Diagnosis?

Duodenal diverticulum: A duodenal diverticulum is a relatively frequent outpouching of the duodenum, mostly to the left (Fig. 9.24a). It is asymptomatic in most cases. Rarely diverticula are found in other segments of the small bowel (Fig. 9.24b).

Fig. 9.23 Analyze the relevant radiograph from Ms. Slimline's small-bowel examination.

I Small-bowel Diverticulum a Duodenal diverticulum a Duodenal diverticulum

Mekel Diverticulum Fluoroscopy
Fig. 9.24a Observe the duodenal "C" configuration and the air-distended stomach cranially. Diverticula that originate from the inner curvature of the C (arrow) can cause problems, particularly if they reach the size depicted in this image and

b Jejunal diverticulum b Jejunal diverticulum

Vitelline Duct Remnant
if they also involve the papilla of Vater. In that situation it becomes very difficult for the endoscopist to find and, if necessary, enter the papilla. b This diverticulum is located immediately distal to the ligament of Treitz (arrows)._

Do You Know about the Meckel Diverticulum?

Meckel diverticulum has been encountered in up to 3% of patients in a series of autopsies performed for unrelated reasons. It is a remnant of the vitelline duct, located in the ileum within 100 cm or so of the ileocecal valve and often connected to the umbilicus by a fibrous ligament. Frequently, ectopic gastric or pancreatic tissue is found within the diverticulum.

Crohn disease: Crohn disease is a granulomatous inflammatory condition that can manifest itself in any segment of the gastrointestinal tract between the lips and the anus but that most commonly affects the terminal ileum (Fig. 9.25a). Alternating relatively normal areas of mucosa surrounded by mucosal ulcerations and scarring result in a "cobblestone" appearance of the mucosa on contrast examination. The entire bowel wall is affected and involvement of intestinal segments is often discontinuous

I Crohn

Disease a, b Terminal ileitis

Terminal Ileum Crohn

I Crohn

Disease c Fistula formation c Fistula formation

Crohn Fistula

Fig. 9.25a The terminal loop of the ileum has a significantly smaller caliber than the proximal loops. The lumina lie wide apart as a sign of bowel wall swelling and hypertrophy of intervening mesenteric fat. Fluoroscopy of the terminal ileum loop shows minimal mobility of this segment. Fistulas are not detected. b MRI is increasing its role in imaging for inflammatory bowel disease—a welcome development because affected patients are often young and radiation exposure must be kept to a minimum. The thickened wall of the terminal ileum is well appreciated. c In this case contrast was injected via a small catheter that was introduced into a cutaneous fistula. A complex fistula system becomes apparent that communicates with the bowel (arrow). Some call these systems the "fox hole."

I Intussusception

Small Intestine Disorders

Fig. 9.26a The invaginated segment of bowel appears as a contrast-engulfed "sausage" (arrows) within the outer bowel lumen. In this case a polyp was the lead point of the intussusception. b On ultrasound thecharac-teristic "double-doughnut sign" is appreciated. The reduction with air takes place under fluoroscopy to monitor the success of the procedure. c The invaginated bowel segment is visible in the middle abdomen (arrow). The small bowel is free of air. d The final radiograph shows the resolution of the intussusception. The air column has reached the small bowel, proving successful reduction.

Multiple Small Bowel Crohn Strictures

("skip lesions"). Long segmental strictures and intramural and intestinocutaneous fistulas may be another complication (Fig. 9.25c). After multiple resections of the small bowel, a short bowel syndrome can ensue: the residual ileal segment grows wider and shows thicker folds.

Celiac disease: In this malabsorption entity due to gluten intolerance, the number of folds visible in enteroclysis changes to less than 1 per cm in the jejunum and to more than 2 per cm in the ileum.

Intussusception: An intussusception develops when one segment of the intestine is pulled into the contiguous distal segment of bowel (Fig. 9.26a). It tends to occur most commonly in children; about 90% of intussusceptions in children are ileocolic. The cause is often a so-called "lead-point" (a polyp or a mucosal hyperplasia) that is picked up by the intestinal peristalsis like a food particle and thus pulls the attached segment of bowel with it. The two main resulting problems are intestinal obstruction and vascular compromise because the mesentery follows the bowel and blood vessels can twist and become blocked. An intussusception must be treated quickly to prevent a bowel infarction. Today this is done primarily under ultrasound control (Fig. 9.26b). Water or air is administered through a rectal tube. The water column or air pressure then pushes the invaginated intestinal segment back and thus reduces the intussusception. When air insufflation is used, the procedure is usually performed under fluoroscopic control (Fig. 9.26c, d). While an intussusception is often idiopathic or due to temporary reactive mu-cosal hyperplasia in children, a symptomatic intussusception in an older patient should always prompt a careful work-up to determine the underlying etiology as it is commonly caused by small-bowel tumors in the adult. On modern multidetector-row CT of the abdomen we often see asymptomatic transient small-bowel intussusceptions that are of no clinical significance.

Small-bowel tumors: Tumors of the small bowel are extremely rare and the benign ones (for example, leiomyomas; lipomas, Fig. 9.27) make up the majority. Chances are that you will not see a patient with a small-bowel tumor in your professional lifetime.

• Diagnosis: Paul has already jotted down a short report as Llewellyn puts his lead apron neatly back on the hanger. "Crohn disease of the terminal ileum, no fistulas detectable so far" is his diagnosis. Llewellyn has not told him a thing during the procedure, not a single hint, but has taken the necessary radiographs under fluoroscopy rapidly and carefully. Now he takes a look at Paul's report on the table. "Bingo," says Llewellyn. He pleasurably takes a noisy sip of coffee. "I just hope the gastroenterologists get a handle on this one. The patients are so awfully young. Well, Paul, the next barium enema is yours. I hope you have done your reading. I'll talk you through it if you get stuck."

I Small-bowel Lipoma

Small Intestine Disorders
Fig. 9.27 This small-bowel enema shows a tumor in the intestinal lumen (arrows). The histological analysis of the resected segment confirmed a lipoma, which can also sometimes be diagnosed with confidence in CT thanks to the characteristic negative density.
Why Gluten Free

Why Gluten Free

What Is The Gluten Free Diet And What You Need To Know Before You Try It. You may have heard the term gluten free, and you may even have a general idea as to what it means to eat a gluten free diet. Most people believe this type of diet is a curse for those who simply cannot tolerate the protein known as gluten, as they will never be able to eat any food that contains wheat, rye, barley, malts, or triticale.

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