Overview
A colonic diverticulum is a pouch-like protrusion of the wall of the colon outward. They can be single, but are more often a series of sac-like protrusions from the intestinal lumen outward. Colonic diverticula can be divided into two categories: true and acquired. True diverticula are congenital total weaknesses of the colonic wall, with diverticula containing all layers of the intestinal wall. Acquired diverticulum is a herniation of mucosa through a weak point in the muscular layer of the intestinal wall, so it is secondary to increased pressure in the intestinal lumen, forcing the mucosa to protrude outward through a weak area in the muscular layer of the intestinal wall.
Diagnosis
Proper diagnosis is an extremely important part of judging the condition and deciding the course of treatment. Some patients with mild symptoms and signs of diverticulitis can be treated successfully in outpatient conditions, â⒬“ others who present with acute life-threatening conditions require emergency resuscitation and life-saving surgery. Therefore, the most important assessment is the clinical examination and frequent repeat examinations of the patient. This includes not only history and physical examination, pulse and temperature, but also serial hemograms, upright and plain abdominal radiographs.
The diagnosis of left-sided colonic diverticulitis is straightforward when all the typical signs and symptoms are present. In such cases no ancillary tests are needed and treatment should be based on assumptions, unfortunately most cases are often unclear and the diagnosis and the severity of the attack may not be clear after the initial clinical examination. Only 7% of cases of acute right-sided colonic diverticulitis are correctly diagnosed preoperatively. Preoperative studies are generally unhelpful in making the diagnosis and may only delay appropriate treatment.
Three tests are useful in establishing the clinical diagnosis of acute left-sided colonic diverticulitis and detecting the presence of significant inflammatory complications: endoscopy, dual contrast air-barium enucleation, and CT scan of the abdomen and pelvis. In the acute setting endoscopy should generally be avoided, as insufflation can induce perforation or aggravate an already existing perforation. If the presence of other rectosigmoid lesions is considered, which would alter the treatment, endoscopy may be performed but should not be inflated.
Barium enema can be used urgently to diagnose diverticulitis, but there is a risk of barium spillage into the abdominal cavity, which would cause severe vascular deflation and death. Hackford et al. advocate a barium enema 7 to 10 d after the inflammatory process has subsided to clarify the diagnosis. If a more urgent diagnosis is needed to guide treatment, a water-soluble contrast enema can be used so that even if there is a spill of contrast into the abdominal cavity, it will not cause a serious reaction.
CT scans are non-invasive and generally confirm clinical suspicion of diverticulitis. CT scans are more effective in diagnosing complications of diverticulitis: 10 of 10 abscesses and 11 of 12 fistulas were diagnosed on CT scan compared to 2 of 8 abscesses and 3 of 8 fistulas on radiography. percutaneous puncture for drainage of abscesses.
The diagnosis of diverticular colonic vesicovaginal fistula is best established by CT scan, which is definitive in about 90% of patients and may require cystoscopy with focal inflammatory processes at the fistula site; barium enema angiography and fiberoptic sigmoidoscopy are not very effective and are positive in only about 30% to 40% of cases.
Abdominal plain films may show colonic obstruction secondary to sigmoid lesions. Water-soluble contrast enucleation can confirm the diagnosis.
Colonic diverticulosis: treatment measures
(A) Internal treatment
Acute diverticulitis without complications can be treated by internal medicine, including fasting, gastrointestinal decompression, intravenous rehydration, broad-spectrum antibiotics and close clinical observation. In general, gastrointestinal decompression is used only in the presence of vomiting or evidence of colonic obstruction. There are many antibiotics available to control gram-negative aerobic and anaerobic bacilli, and acute diverticulitis that resolves on its own without antibiotics is often seen. Supplemental dietary fiber and antispasmodics have no place in the management of patients with acute diverticulitis. In most cases, their symptoms will rapidly resolve with medical treatment.
(ii) Surgical indications
The cases currently considered to require surgical management can be divided into two main categories, one for patients with uncomplicated diverticulosis: the other for diverticulosis causing various complications, combined
Those with the following conditions should be treated surgically.
① Acute diverticulitis first attack does not respond to medical treatment;
② Acute recurrent diverticulitis, even if the first attack by medical treatment was satisfactory, but when the recurrence should be considered for selective resection;
③ <50 years old who had an acute diverticulitis attack and obtained success by medical treatment should undergo elective surgery to avoid future emergency surgery;
④Diverticulitis is a fatal disease due to the inability to provoke an adequate inflammatory response in immunodeficient patients, and perforation and rupture into the free abdominal cavity are very common;
⑤ Acute diverticulitis complicated by abscess or cellulitis;
(6) acute diverticulitis with diffuse peritonitis;
(7) Acute diverticulitis complicated by fistula formation;
(8) Acute diverticulitis complicated by colonic obstruction.
Among the above indications for surgery, special care should be taken not to mistake patients with intestinal irritation syndrome combined with colonic diverticulosis for diverticulitis, especially in uncomplicated cases. Morson reported that about 1/3 of specimens undergoing elective surgery for diverticulitis have no pathological evidence of inflammation. Therefore, in the absence of objective signs of inflammation such as fever or leukocytosis, colonic diverticulosis complicated by irritable bowel syndrome should be treated as functional colonic disease and should not be the subject of unnecessary resection.
(C) Surgical treatment
1. In cases of elective surgery, a thorough examination and adequate preparation should be made before surgery, including intestinal cleansing and antibiotic preparation. Since the sigmoid colon is the most frequently invaded site, the sigmoid colon is the first segment to be resected, the extent of resection is controversial, and the appropriate proximal and distal ends must be determined.
Not all colonic diverticula need to be removed, but no diverticula should be left distal to the anastomosis. Colon with previous diverticulitis always has changes in the colonic plasma membrane surface due to prior inflammation and infiltration of the colonic mesentery, which helps in identification. However, even after satisfactory resection, many patients with pre-existing diverticula will enlarge again, diverticulosis will develop, and approximately 7-15% will have a recurrence of acute diverticulitis. The rate of recurrence of symptoms after a certain period of time is the same in patients treated medically and in those who undergo surgery.
In patients who undergo resection because they do not respond to medical treatment, preoperative bowel cleansing may not be appropriate. In such cases, the Hartmann procedure may be chosen, or an intraoperative proximal colonic lavage may be used followed by a one-stage end-to-end anastomosis without a colostomy. In recent years, the trend has been to prefer a one-stage anastomosis. Even pus cavity resection after a phase anastomosis, without fecal diversion.
2, for the acute inflammatory complications of diverticular disease for surgery, the first should be given from the intravenous second or third generation cephalosporins and metronidazole. Stress doses of steroids may need to be given intravenously in some patients. The preoperative surgeon should estimate the pelvic anatomy and may require a temporary colostomy or ileostomy, which should be explained to the patient and her family before surgery to prepare them.
In addition, due to the acute inflammatory response, the ureter can often be involved, and the chance of accidental injury during acute surgery is great.
Patients undergoing acute surgery are advised to take a cystotomy position and explore through a midline dissection incision, the purpose of which is to determine the diagnosis, determine the inflammatory status of the abdominal cavity, understand the adequacy of bowel preparation, and the presence of other lesions. Colcock reported that up to 25% of patients can have a preoperative diagnosis of diverticulitis with abscess or fistula, which turns out to be a perforating carcinoma. Obviously, if it is a carcinoma, the target and extent of resection will change.
For this reason, Haghes et al. (1963) divided the inflammatory complications of diverticular disease into four categories.
(i) limited peritonitis ;
(ii) confined peri-colonic or pelvic abscesses;
(iii) diffuse peritonitis following peri-colonic or pelvic abscess penetration;
(iv) diffuse peritonitis secondary to free perforation of the colon.
Later, Hinchey et al. (1978) proposed the same classification.
① peri-colonic or mesenteric abscesses ;
(ii) encapsulated pelvic abscess;
(iii) diffuse purulent peritonitis;
A more complex and refined classification was proposed by Killingback in 1983.
Diverticular disease with complications is best treated by both drainage of the abscess, control of peritonitis, and resection of the inflammatory lesioned bowel segment. In recent years, it has been well documented that conservative drainage and stoma procedures have significantly higher morbidity and mortality rates than resection procedures. The previous three-stage approach has been replaced by a one-stage and two-stage approach.
While there is a great deal of current data showing that phase I surgery is safe, there are several factors that must be taken into account when making a specific decision about phase I or II surgery.
① An empty intestinal cavity and absence of fecal matter indicates satisfactory intestinal preparation, or this requirement can be achieved by lavage during surgery;
(ii) The absence of edema in the intestinal wall;
(iii) good blood supply to the proposed anastomosed bowel segment;
④ abdominal cavity infection and contamination are limited and not too serious;
⑤ The surgeon’s knowledge of the patient’s general condition and the presence of other special risk factors. The main reason for the recent interest in one-stage anastomosis is the difficulty of re-establishing intestinal continuity in patients who have had diffuse peritonitis and underwent Hartmann’s procedure.
As for the second-stage procedure, two options are available: a Hartmann-type distal suture closure with a proximal colostomy and a second-stage reanastomosis. This procedure is generally indicated when resection is performed due to diffuse septic peritonitis or diffuse fecal peritonitis. The other is a one-stage anastomosis with an adjuvant proximal colostomy or ileostomy or endocolonic bypass, which is generally indicated when surgery is performed for non-diffuse septic peritonitis or diffuse fecal peritonitis and a one-stage anastomosis is not appropriate due to other factors.
There is still disagreement about surgery for right-sided colonic diverticulitis. According to Schmit et al, limited colectomy is sufficient if cancer can be excluded, and if cancer cannot be excluded or intestinal viability is questionable, right hemicolectomy should be performed. However, Fischer and Farkas believe that patients with acute diverticulitis with limited cellulitis can be treated successfully with postoperative application of antibiotics as long as cancer can be excluded and cannot be resected.
[Epidemiology
Acquired colonic diverticulosis is present in a significant number of people in Western countries, but the true prevalence of this disease is difficult to determine. Radiographic data overestimate the prevalence because the subjects examined are those with gastrointestinal symptoms. Conversely, autopsy data underestimate the prevalence because small diverticula in the colon are highly likely to be missed during postmortem examination.
Acquired diverticulae of the colon occur in about 5-10% of people over 45 years of age, increasing to 2/3 of those >85 years of age who have the disease. In conclusion, regardless of the true number, acquired colonic diverticula increase with age on autopsy and barium enema x-ray.
Acquired colonic diverticulosis was rarely reported before the 20th century. Although the anatomy of colonic diverticulosis was described in the early 18th century, the relationship between clinical signs and pathological findings was not recognized until the 20th century. The reason for the rapid prevalence of acquired diverticular disease in the mid-20th century in Western countries can be attributed to the reduced consumption of fiber in the diet.
Painter and Buikitt noted that no case of diverticulitis was encountered in Africa for 20 years, suggesting that the increased prevalence of diverticulosis and its complications in industrially developed countries is due to the substitution of flour and refined sugar in the diet for coarse foods of all kinds. While most of the evidence for this theory is inferential and intuitive; evidence for the importance status of dietary fiber comes from epidemiological studies of first-generation Japanese born in Hawaii, whose diets have been westernized. The incidence of diverticulitis was determined to be increased compared to crystals born in native Japan.
Acquired colonic diverticulosis is predominantly female, with Parks (1969) reporting a male to female ratio of 2:3. The mean age at presentation is 61.8 years, with more than 92% over 50 years of age. 96% of patients have an invasion of the sigmoid colon; 65.5% have the sigmoid colon as the only site of invasion. About half of the patients had a symptomatic time frame of <1 month before presentation.
The symptomatic time frame was shorter for more extensive lesions than for more limited lesions, and 65% of patients initially hospitalized were treated medically and 35% surgically. More than 90% of the patients were within 5 years of the initial presentation. The mortality rate for second-episode patients is twice that of first-episode patients. Moreover, it is common for symptoms to persist or recur regardless of medical or surgical treatment.
Clinical manifestations
(A) Colonic diverticulosis
About 80% of patients with colonic diverticulosis are asymptomatic, and if they are eventually detected, it is only accidentally discovered during a barium enema X-ray or endoscopy. Symptoms associated with diverticula are actually symptoms of their complications – acute diverticulitis and bleeding – and symptoms such as occasional abdominal pain, constipation, and diarrhea in patients with uncomplicated colonic diverticulosis are due to concomitant dynamic disease, while the presence of diverticula is only coincidental.
On physical examination there may be mild tenderness in the left lower abdomen, and sometimes a hard tubular structure such as one can be palpated in the left colon. Despite the abdominal pain, there is no fever or leukocytosis because there is no infection. In addition to diverticula, segmental intestinal spasm and muscle thickening can be seen in the barium enema film, resulting in narrowing of the intestinal lumen and a jagged appearance.
(B) Acute diverticulitis
Acute attacks have varying degrees of limited abdominal pain, which can be stabbing, dull and colicky, mostly in the left lower abdomen, occasionally in the suprapubic, right lower abdomen, or the entire lower abdomen. Patients often have constipation or frequent defecation, or both in the same patient, and the pain may be relieved by exhaustion. Inflammation adjacent to the bladder may produce urinary frequency and urgency. Depending on the site and severity of the inflammation, nausea and vomiting may also be present.
On physical examination there is low-grade fever, mild abdominal distention, tenderness in the left lower abdomen, and a mass in the left lower abdomen or pelvis, occult blood in the stool, and rarely blood in the feces with the naked eye, but in the presence of periverticulitis hemorrhage rarely occurs, in addition to mild to moderate leukocytosis.
Acute diverticulitis is the most common complication of colonic diverticulosis, and Rodkey and Welch reported that 43% of the cases of colonic diverticulosis admitted to Massachusetts General Hospital in the United States were acute diverticulitis and local infection. Acute diverticulitis can occur in any part of the colon, including the rectum. In Western countries, the sigmoid colon is the most common site, while in Japan and China, the right side of the colon is more common. About 10% to 25% of patients known to have diverticulosis have at least one episode of acute diverticulitis.
Although massive rectal bleeding is rare in diverticulitis, the initial Shaanxi surgery in 30-40% of patients with acute diverticulitis is positive for fecal occult blood. Approximately 10% to 25% of patients require emergency surgical management despite 48h of treatment with no improvement or worsening. About 70% of patients who undergo emergency surgery have a critical initial presentation. Immunologically compromised patients do not respond well to medical therapy, and Perkins et al. reported that 100% of these patients failed with fasting, rehydration, and antibiotics, and that surgery had a high rate of failure and mortality.
Therefore, most transplant centers recommend an elective colectomy prior to transplantation in patients with proven diverticulitis. Acute diverticulitis is uncommon in <40% of patients and its clinical course is aggressive; Freishlay et al. reported that 77% of patients under 40 years of age required surgical treatment at their first episode and that these patients often presented with severe complications such as free perforation.
Diverticula in the right colon may be part of the development of a total colonic diverticulum, an isolated process involving a few diverticula in the right colon, or more commonly, an isolated single true diverticulum. In midday patients right-sided diverticulitis often resembles acute appendicitis.
(C) Acute diverticulitis complicated by abscess
The most common complication of acute diverticulitis is the development of an abscess or cellulitis, which can be located in the mesentery, abdomen, pelvis, retroperitoneum, buttocks, or scrotum. A painful mass can often be found in the abdomen or pelvis on rectal examination, and the abscesses caused by diverticula are accompanied by signs of sepsis of varying degrees.
(D) Acute diverticulitis complicated by diffuse peritonitis
When a confined abscess ruptures or a diverticulum perforates freely into the peritoneal cavity, septic or fecal peritonitis can result. Most such patients present with acute abdomen and varying degrees of septic shock. Mortality rates of 6% have been reported for septic peritonitis and up to 35% for fecal peritonitis.
(E) Acute diverticulitis with fistula formation
Fistulas occur in approximately 2% of all patients with acute diverticulitis, but are present in 20% of those who eventually undergo surgery for diverticulosis. Internal fistulas may arise from adjacent organs adhering to the diseased inflamed colon and adjacent mesentery, with or without the presence of an abscess. As the inflammatory process worsens, the abscess in the diverticulum decompresses itself and collapses into the adherent cavernous organ, resulting in a fistula.
This outcome often eliminates the need for emergency surgery because the abscess is effectively drained. About 8% of patients will develop multiple fistulas, more often in men than in women, presumably because the female uterus acts as a barrier separating the sigmoid colon from other cavernous organs, and most patients with diverticular colonic vesicovaginal fistulas or colovaginal fistulas have had a prior hysterectomy. Fistulas caused by diverticulitis can invade many organs, and most patients with colonic cutaneous fistulas – external fistulas – occur as a result of an anastomotic complication, anastomotic leak, after bowel resection for diverticulosis.
(F) Acute diverticulitis complicating intestinal obstruction
Foreign in the large intestinal obstruction caused by diverticulosis accounted for about 10%, domestic diverticulosis caused by complete colonic obstruction is rare, but due to edema, spasm and inflammatory changes of diverticulitis due to partial obstruction is common.