Oscar M. Laudanno and Ronald Estrada Seminario
The diverticula of the colon are acquired herniations of the mucosa and submucosa through the muscular layers of the colon, which produce a deformation in the wall of the organ, which produce a deformation in the wall of the organ in the form of a sacculation.
The term diverticular disease of the colon groups the processes of prediverticular disease, diverticulosis and diverticulitis, which are considered three evolutionary stages within the same disease.
According to radiological studies carried out in healthy populations, approximately 8% of individuals older than 40 years and more than 60% of those older than 60 years present colonic diverticula.
The worldwide distribution of this disease, as well as its frequency within the same geographical areas, suggests that its appearance depends on the degree of refinement existing in the usual diet, which is associated with a reduction in the content of vegetable fibers.
Colon motility disorders . At present, only two types of waves tend to be evaluated, which are those that originate the two main types of contractions and colonial movements: those of segmentation and those of massive or propelling movements.
In cases of diverticular disease, pressure registers have been obtained with an increase in the number of waves and with an amplitude nine times greater than in healthy controls, when faced with different pharmacological agents (eg, morphine).
For this reason, diverticula are thought to be the consequence of intrinsic alterations in the motility of the colon, probably related to modifications of the diet, which produce a decrease in fecal volume and therefore require greater intervention of the sigmoid colon.
Alteration of the muscular layer . The alteration of the muscular layer is the most constant finding that can be observed in the colon of patients with diverticular disease. This alteration consists of a thickening of the inner circular muscle layer, which takes on a wavy appearance, and a thickening of the tapeworms (longitudinal smooth muscle) that sometimes take on an almost cartilaginous consistency; This trabeculation of the muscular layer is an acquired defect, probably related to the excessive segmentation that occurs in the sigmoid colon, the place where colonic diverticula are most frequently located.
Eating habit and intestinal habit . Various epidemiological and experimental data support the theory that attributes the development of this disease to dietary abnormalities.
Such abnormalities consist of a decrease in the amount of fibers, due to refinement in food products, which lead to almost complete absorption in the small intestine of the ingested food; This results in a decrease in fecal content and a higher viscosity thereof, which favors colonic segmentation movements and the consequent development of diverticula.
At present, diet is evaluated as an etiological factor, but not only as a producer of a local mechanical alteration, but as a factor that can alter colonic motility by neurogenic and hormonal mediators.
Probably, and related to this eating habit, is the intestinal habit of patients suffering from diverticular disease of the colon, since more than 50% of them have constipation.
Psychological stress . Given the relationship between the higher nervous centers, linked to the emotional sphere, and colonic motility, it is assumed that this factor could play a role in the development of diverticular disease.
Based on the results of epidemiological, radiological, manometric and pathological studies, a hypothesis can be raised that explains the pathology of these various diverticula.
Manometric tests indicate that the diverticula are the consequence of an intrinsic disorder of the motility of the colon that is associated with a disorder of muscle function, particularly of the sigmoid colon. The thickening that occurs as a result of this alteration in the muscle layer is not true hypertrophy or hyperplasia of the muscle cells.
The fact that diverticula are located at the weakest points of the intestinal wall, those where the blood vessels penetrate, indicates that intraluminal pressure plays a very important role in their formation.
The maintenance of the explained etiological factors, especially the eating habit for long periods of time, leads to the alteration of the colon wall (muscular and segmentation alteration) that explains the formation of diverticula. In the cases of simple diverticulosis, without thickening of the muscle wall, the etiopathogenic reasoning presented is not useful, so it is possible that the mechanism of production of this disorder is of another nature.
Symptoms and signs
Diverticular disease of the colon does not have specific clinical characteristics; As a general rule, the patient's symptoms are similar to those described in cases of irritable bowel syndrome, unless diverticulitis occurs.
According to the classification of Manousos and Truelove, five clinicians can be recognized:
Asymptomatic diverticulosis . it is an incidental finding on an enema colon radiograph.
Symptomatic diverticulosis . The clinical symptomatology consists of colicky abdominal pain, either chronic or intermittent, located in the left iliac fossa and accompanied or not by abdominal distension; This occurs within the framework of an intestinal rhythm with a clear tendency to constipation or alternating between constipation and diarrhea. Abdominal pain is attributed to colonic motility disorders and not to inflammatory complications.
Acute diverticulitis . It is defined as that complication due to the macro or microperforation of a diverticulum. The importance of the clinical picture depends on the extradiverticular extension of the inflammation.
The most frequent clinical signs are pain, located in the left iliac fossa (left side appendicitis), and fever or low-grade fever. Physical examination may reveal tenderness, with some degree of abdominal defense, and even a painful mass may be palpated; the examination should be completed with a digital rectal examination.
Complicated acute diverticulitis . Fortunately, complications are rare: a) pericolic abscess : it usually presents as a clinical picture of intestinal occlusion or subocclusion with fever, pain in the left iliac fossa and a palpable mass on abdominal examination. The radiological study by means of a barium enema can establish the diagnosis; b) fistulous path: Enterocolic, colonocolic, abdominal wall and pelvic floor fluids have been observed, originating ischiorectal and perianal, colovaginal and colovesical abscesses, the latter more frequent in men. Likewise, there may be communication between the abscess and a tributary venous vessel of the portal tree, giving rise to portal septicemia. This last complication is exceptional; c) perforation with generalized peritonitis . it is the most serious complication, with a high mortality rate of around 30%.
Hemorrhagic diverticulosis . It is defined by the presence of rectal bleeding that is usually intense; in general, small and continuous blood loss should not be attributed to this condition, unless another type of pathology is ruled out. Patients who have had an episode of severe rectal bleeding are more likely to have a new episode. Sometimes the intensity of the bleeding can constitute a true medical emergency.
In patients with diverticulosis, the plain abdominal X-ray does not present any particularities. The diagnosis is most often established by a study with a barium enema, which also represents the most appropriate method to determine the magnitude and severity of diverticulosis. Diverticula can affect the entire colon, but are most often found in the left colon and especially in the sigmoid colon. Common radiographic findings include colonic spasms, sacculation of the colon, and retention of the contrast medium within the diverticula.
Evaluation of the colon is as important to confirm the diagnosis as it is to rule out the presence of a neoplasm.
Lower gastrointestinal endoscopy is probably more useful for the evaluation of concomitant lesions of the colon (colon carcinoma) than for the diagnosis of diverticular diseases.
In patients with profuse bleeding, emergency angiography is considered the initial procedure of choice. angiography is specific and highly sensitive if bleeding is fast enough. First, the superior mesenteric artery is evaluated, since the incidence of acute bleeding is higher on the right side. Subsequently, the inferior mesenteric artery is evaluated followed by the celiac trunk, which may reveal a source of unexpected intestinal bleeding in the upper gastrointestinal tract. Angiography has high specificity and can reveal the presence of tumors, diffuse mucosal hemorrhage, or the characteristic angiographic signs of angiodysplasia, such as delayed venous emptying, the presence of vascular tangles, or early venous filling.
In diverticulitis, the initial laboratory studies that often contribute to the diagnosis include a complete blood count, urinalysis, and plain abdominal radiography in the supine and erect positions. The white blood cell count is generally elevated with a predominance of porimorphonuclear leukocytes. Computed tomography scan is generally the study of choice, to confirm the presumptive diagnosis of diverticulitis, to detect the location of the inflammation and to provide valuable information about the presence of an abscess, a ureteral obstruction or a fistula between the colon. and the bladder. Ultrasound may reveal a thickened and inflamed hypoechoic colon wall. Percutaneous drainage of an abscess can also be carried out under ultrasound guidance.