Gastrointestinal Diverticula
There are many varying types of gastrointestinal diverticula.
Many are defined by the location they occur in while others are often defined by their characteristics.
Fig. 2: Types of Diverticula
Oral Cavity Diverticulum
An oral cavity diverticulum is a very rare type of false diverticulum.
There have been approximately 10 case reports identified in the literature.
These diverticula generally arise from the buccal mucosa and are a false diverticulum as a result of a defect through the buccinator muscle.
Zenker's Diverticulum
A Zenker’s diverticulum is a false diverticulum.
It is defined as an outpouching of mucosa and submucosa in Killian's Triangle (an area of decreased muscle strength).
Common symptoms of presentation include trouble swallowing,
sensation of something stuck in throat,
halitosis,
and regurgitation.
These are best evaluated on fluoroscopy.
Fig. 3: Zenker's Diverticulum
Killian-Jameson Diverticulum
A Killian-Jameson diverticulum is a false diverticulum.
These are generally located anteriorly and laterally below the cricopharyngeal muscles and are outpouchings through muscular defects.
Killian-Jameson diverticula are often asymptomatic.
These are best evaluated on fluoroscopy.
Fig. 4: Killian-Jameson Diverticulum
Traction Diverticulum
A traction diverticulum is a type of true diverticulum.
It is secondary to pulling along the outer portion of the esophagus,
which can be due to inflammation,
fibrosis,
or scarring.
This diverticulum is best evaluated on fluoroscopy.
Fig. 5: Traction Diverticulum
Epiphrenic Diverticulum
An epiphrenic diverticulum is a type of false diverticulum.
It is secondary to increased intraluminal pressure and as a result labeled as pulsion diverticula.
Epiphrenic diverticula occur slightly above the lower esophageal sphincter.
They are best evaluated on fluoroscopy.
Epiphrenic diverticula can be associated with achalasia,
hiatal hernia,
and strictures.
Treatment options include myomectomy or diverticulectomy.
Fig. 6: Epiphrenic Diverticulum
Esophageal Diverticulum with Fistula
Esophageal diverticula rarely can fistulize.
These fistula include bronchoesophageal,
gastroesophageal,
or even cutaneous esophageal fistula.
Surgical repair is often required.
Fig. 7: Esophageal Diverticulum with Esophageal Fistula
Esophageal Pseudodiverticulosis
Esophageal pseudodiverticulosis is an uncommon form of diverticulosis often found in elderly males.
Nearly all patients with this condition have esophageal strictures.
Other associated conditions include gastroesophageal reflux,
cancer,
and candidiasis.
It occurs secondary to dilation of mucosal gland ducts.
It is best evaluated on fluoroscopy which demonstrates many small outpouchings,
which are usually less than 5 mm in size.
Fig. 8: Esophageal Pseudodiverticulosis
Gastric Diverticulum
A gastric diverticulum can be a true or false diverticulum.
Gastric diverticula are rare and often seen in older adults,
both female and male.
Most true diverticulum are seen along the posterior fundal wall.
Gastric diverticula can be well evaluated both on fluoroscopy and CT.
Treatment options include surgical resection.
Fig. 9: Gastric Diverticulum
Fig. 10: Gastric Diverticulum on MRI
Duodenal Diverticulum
A duodenal diverticulum can be a true or false diverticulum.
Duodenal diverticula are common and often asymptomatic.
A true duodenal diverticulum often occurs in the first portion of the duodenum.
A false duodenal diverticulum often occurs in the second and third portion of the duodenum.
Fig. 11: Duodenal Diverticulum
Duodenal Diverticulitis
Duodenal diverticulitis is a rare complication of duodenal diverticula.
There is often thickening of the second and third portion of the duodenum.
Diverticulitis is rest evaluated on CT.
In addition to duodenal diverticulitis other forms of small bowel diverticulitis including jejunal and ileal diverticulitis are possible.
Fig. 12: Duodenal Diverticulitis
Jejunal Diverticulosis
Fig. 13: Jejunal Diverticulosis
Jejunal Diverticulitis
As jejunal diverticulosis is an uncommon diverticulum,
jejunal diverticulitis is often not on the differential for abdominal pain.
Jejunal diverticulitis can be uncomplicated,
but sometimes due to delay in diagnosis can present with peritonitis,
abscess formation,
or perforation.
Fig. 14: Jejunal Diverticulitis
Fig. 15: Jejunal Diverticulitis with Perforation
Fig. 16: Jejunal Diverticulitis Mimicking Intussusception
Fig. 17: Jejunal Diverticulum with Bezoar
Ileal Diverticulitis
Fig. 18: Ileal Diverticulitis
Meckel's Diverticulum
A Meckel’s diverticulum is a true diverticulum.
Meckel’s diverticula are congenital lesions containing ectopic gastric mucosa.
They are often described by a rule of 2; 2% of population,
within 2 feet of ileocecal valve,
symptomatic diverticula presenting before 2 years of age,
and 2 inches in size.
Complications of Meckel’s diverticula include bleeding,
obstruction,
and intussusception.
Fig. 19: Meckel's Diveritculum
Fig. 20: Meckel’s Diverticulum with Small Bowel Obstruction and Fecalith
Fig. 21: Meckel’s Diverticulum with Cancer
Colonic Diverticulum
Colonic diverticula are mainly false diverticula. They occur due to increased intraluminal pressure on the mesenteric side of the colon often due to low bulk diet and as a result are often seen in Westernized countries.
They are a frequent incidental finding.
They sometimes present with abdominal pain,
constipation or diverticular disease/hemorrhage.
Colonic diverticula can be seen in the entirety of the colon with the most common site being sigmoid colon.
The ascending colon is also an important site of diverticulosis often seen in patients from Asia.
Colonic diverticula are frequently seen on CT with complications often best identified on CT.
Colonic diverticula should be differentiated from colorectal carcinoma.
Fig. 22: Colonic Diverticula
Giant Colon Diverticulum
Giant gastrointestinal diverticula are a rare finding.
These most commonly occur in the sigmoid colon,
representing greater than 90% of cases of giant diverticula.
They can be filled with gas,
stool,
or both gas and stool.
Giant diverticula become giant from smaller diverticulum either due to ball valve mechanism or colonization by gas forming organisms.
These are best evaluated on CT.
Fig. 23: Giant Colonic Diverticulum
Fig. 24: Giant Colonic Diverticulum with Diverticulitis
Cecal Diverticulitis
Cecal diverticulitis usually occurs in false diverticulum and is uncommon.
Cecal diverticulitis is generally limited to a solitary cecal diverticulum and must be differentiated from appendicitis.
Treatment options include surgery.
Fig. 25: Cecal Diverticulitis
Colonic Diverticulitis and Complications
Fig. 26: Diverticulitis of the Sigmoid Colon
Fig. 27: Colonic Diverticulitis with Reactive Small Bowel Inflammation
Fig. 28: Colonic Diverticulitis with Liver Abscess
Abscess formation occurs in approximately 30% of cases of diverticulitis.
CT and MRI can demonstrate enhancing pericolonic fluid collection containing fluid and gas.
Ultrasound can demonstrate pericolonic collection.
Treatment options include antibiotics with CT guided drainage or surgery.
Fig. 29: Colonic Diverticulitis with Abscess
Colovesicular fistulas can be seen in the setting of complicated diverticulitis.
Fistulization can occur to any organ in the line of inflammation.
The most common type of fistula is colovesical fistula,
which accounts for approximately 65% of fistulas,
followed by colovaginal,
coloenteric,
colouterine,
and colocutaneous fistulas.
Fistulas are often best evaluated on fluoroscopic studies or oral contrast enhanced CT/MRI scans.
Fistulas are generally treated with surgery.
Fig. 30: Colonic Diverticulitis with Colovesicular Fistula
Fig. 31: Diverticular Abscess with Inferior Epigastric Pseudoaneurysm
Thrombosis is a known complication of diverticulitis.
Thrombosis starts in smaller veins and can extend to the portal vein.
Fig. 32: Colonic Diverticulitis with Portal Vein Clot