- ULCERATIVE COLITIS (part2)
· In 1983, a group of world experts (the Inflammatory Bowel Disease-Dysplasia Morphology Study Group) published a consensus report on the classification of dysplasia.
· Changes were classified as positive, negative, or indeterminate for dysplasia.
· In addition, dysplasia can be classified as mild, moderate, or severe.
· The distinction among the grades depends in large part on the degree of cytologic changes that are present.
· There is good evidence that dysplastic change precedes frank carcinoma.
· Unfortunately, however, carcinoma may already be present when dysplastic changes are detected.
· It is also recognized that the pathologist may have difficulty deciding whether microscopic changes are due to the normal regenerative changes seen in UC or represent dysplastic changes.
o This is especially true if there is disease activity at the time the biopsy is performed.
· The skill of an experienced pathologist is essential if patients are to be followed colonoscopically.
We perform colonoscopy on all patients with total or left-sided disease on a yearly basis starting approximately 7 years after the onset of symptoms.
· The patient must be properly prepared for colonoscopy so that all of the mucosa can be visualized.
· The colonoscopy must be complete to the cecum, and the endoscopist must search for any suspicious plaque-like or nodular lesions.
· Dysplasia may be present in grossly flat mucosa or may have a villous or nodular appearance.
· At least 10 serial biopsy samples from around the colon and rectum are obtained for pathologic assessment.
· In addition, biopsy samples are taken from any suspicious areas.
o The site of each biopsy is recorded in case early follow-up colonoscopy is indicated.
· With accurate endoscopic and pathologic assessment of the mucosa, a reasonable course of management can be recommended to the patient.
· In patients who have active disease and a diagnosis of mild dysplasia, we attempt to manage the disease medically, to decrease the amount of inflammation, and we perform repeat colonoscopy and biopsy in 3 months.
- If there is no further dysplasia, the patient will undergo colonoscopy in 1 year.
- If mild dysplasia is again present, the patient will undergo repeat colonoscopy in 3 months, and
- if dysplasia is still present, serious consideration will be given to surgical intervention.
- We have no hesitation in recommending surgical intervention in a patient whose biopsy shows moderate or severe dysplasia from an area of quiescent disease.
· We believe there is sufficient risk in these patients to warrant resection.
· The objective of screening is to detect and treat the high-risk patient surgically before the development of cancer.
· Thus, the optimal result would be to find dysplastic changes in the surgical specimen but no carcinoma.
· Although this policy appears to be useful in the detection of high-risk patients, it is not without its pitfalls.
· In our series, we operated on several patients in whom severe dysplasia but no invasive carcinoma was diagnosed on biopsy specimens taken at the time of colonoscopy.
· After colectomy, unrecognized carcinomas were found within the surgical specimens of these patients.
· Lennard-Jones et al. reported that in patients undergoing surgery because of mild dysplasia, 5% had unrecognized carcinomas found in the surgical specimen.
· In patients with moderate dysplasia, 15% had undetected carcinoma, and if the indication was severe dysplasia, 30% of patients had undetected carcinoma.
· This exemplifies the difficulties in relying on only colonoscopic and histologic assessment in surveillance of these patients.
· As previously mentioned, the carcinomas can be flat and plaque-like and difficult to visualize at endoscopy.
- A special circumstance is the patient in whom a biopsy sample is taken of a nodular or polypoid lesion and histologically indicates dysplastic changes.
- These patients are at a particularly high risk.
- Blackstone et al. reported that invasive carcinomas were present in 7 of 25 patients (28%) in whom mild dysplastic changes were found in so-called villous lesions.
o Thus, the presence of a polypoid mass that shows any degree of dysplasia is an indication for surgery.
In summary, we believe that colonoscopic surveillance in patients with long-standing UC is useful.
Carcinoma in Patients With Ulcerative Colitis
- It is generally accepted that the risk of colorectal cancer does not begin until 8 to 10 years after the diagnosis of UC.
- This risk increases approximately 0.5% per year during the second decade and rises to 1% during the third and fourth decades.
- The incidence of carcinoma in patients with UC is the same in the two sexes.
- Carcinoma in UC tends to occur early in life, with a peak incidence in the fourth decade.
- Unlike tumors in patients without UC, whose lesions tend to occur more frequently within the left colon, tumors in patients with UC tend to be multicentric and evenly distributed throughout the colon.
- Other characteristics of these cancers are that they tend to be
o highly aggressive,
o and poorly differentiated.
- For these reasons, they may escape detection colonoscopically or even at surgery.
- As a result, they tend to be discovered at a later stage.
- Another reason for their late detection is that the common symptoms of crampy abdominal pain, change of bowel habit, bleeding, and mucous discharge may be attributed to UC rather than to carcinoma.
As a result of the more advanced stage of the cancer, the prognosis tends to be poor.
- Slaney and Brooke reported an overall 5-year survival rate of 18.6% in patients who developed cancer.
- The Cleveland Clinic examined the long-term survival rate of 79 patients with carcinoma arising in UC in relation to their clinical pathologic staging and compared the survival statistics with those from a group of patients with carcinoma who did not have colitis with equivalent clinical pathologic staging.
- When grouped by Dukes' classification, there was no statistical difference in survival rates.
- The overall 5-year survival rate was 41% when carcinoma and UC coexisted compared with 61% when there was no colitis with the carcinoma.
- The overall results were worse because of the more advanced stage of disease at diagnosis.
- Although severe, acute colitis is the least common form of UC, affecting approximately 15% of all patients with the disease, it can be life threatening. Acute colitis can occur in two forms:
(1) toxic dilatation of the colon with or without significant bleeding and
(2) massive lower gastrointestinal hemorrhage.
Toxic megacolon is defined as a severe attack of colitis with total or segmental dilatation of the colon. Jalan et al. defined toxicity as the presence of any three of the following conditions:
- pyrexia of higher than 38.5° C,
- tachycardia of more than 120 beats/min,
- leukocytosis of more than 10,500 cells,
- and anemia with a hemoglobin value less than 60% of normal.
In addition, one of the following conditions must be present:
- mental changes,
- electrolyte disturbances,
- or hypotension.
- Toxic megacolon can complicate long-standing disease or can occur in patients presenting with their first attack.
- In the latter instance, one must entertain the possibility of CD or an infectious colitis, with the treatment varying depending on the cause.
- Various precipitating factors for toxic megacolon have been identified, including
o antidiarrheal agents,
o barium enema, and
Unfortunately, the cause is unknown but is thought to be due to a paralysis of the myenteric plexus.
- This, in return, may result from a transmural type of inflammatory process that occurs in the acute process.
- Toxic dilatation of the colon is generally considered the most serious complication of UC.
- The colon loses its ability to contract and becomes widely distended, resulting in a thinned wall that is in danger of perforation.
- The most common sites of perforation are around the peritoneal attachments of the splenic flexure and at the cecum.
- The reported incidence of toxic megacolon ranges between 1 and 2.5% of patients hospitalized with UC.
The clinical presentation of toxic megacolon is dramatic.
- The patients may suddenly become acutely ill with rapid progression of symptoms that include fever, mental aberrations, tachycardia, tachypnea, and bloody diarrhea.
- Abdominal pain may be diffuse and severe but may be lacking, particularly in the patients who are taking high-dose steroids.
- Sigmoidoscopy may reveal changes typical of ulcerative proctitis.
- The diagnosis can usually be made on a plain radiograph of the abdomen, which shows dilation of the large bowel wall.
- More invasive studies, such as colonoscopy or barium enema, are both unnecessary and dangerous.
Patients who present with signs of localized or generalized peritonitis, radiologic evidence of perforation, or systemic instability should undergo immediate surgery.
- Otherwise, intensive medical management, consisting of high-dose parenteral steroids and intravenous fluids, should be initiated immediately.
- Patients tend to be dehydrated and may have electrolyte imbalances because of losses from vomiting and diarrhea.
- These imbalances must be corrected, and the patients who are anemic should undergo transfusion.
- Restriction of oral intake is initiated along with nasogastric suction to avoid further intestinal distension.
- Although controversial, we believe broad-spectrum antibiotics should be administered because of the potential for bacteremia caused by the increased permeability of the bowel wall and the possibility of microperforation that often exists along the peritoneal attachments.
The patient with toxic megacolon
- must be observed very closely with serial examinations every 2 to 4 hours.
- Patients who do not show any improvement in a 24-hour period or patients who deteriorate at any time should be operated on.
- This aggressive policy is based on reports that show that although mortality rates increase significantly with prolonged medical treatment, the proportion of patients whose disease resolves does not.
The options of surgical therapy include
- subtotal colectomy and ileostomy,
- total proctocolectomy,
- and the "blowhole procedure" as advocated by Turnbull et al.
Our procedure of choice is subtotal colectomy and ileostomy.
- We believe that with this procedure, most of the disease is removed and the patient's recovery is usually rapid.
- Although the rectal remnant discharges some small quantities of mucus and blood, it is not usually a significant problem.
- When this procedure is performed in the presence of toxic megacolon, a lengthy incision must be used to more easily mobilize the splenic flexure without placing undue tension on it.
- Iatrogenic perforations of the colon most often occur when the splenic flexure is put under tension.
- We prefer to oversew the lower end of the sigmoid and bring it out through a separate incision in the left lower quadrant.
- It is buried in the subcutaneous tissue without closing the skin over it.
- In this way, there is no foul-smelling discharge as occurs with a mucous fistula, and if the suture line breaks down, the rectum will not discharge into the abdomen.
In the majority of cases of toxic megacolon, significant bleeding is not the major problem; therefore, we have no hesitancy in leaving the remaining rectum in situ for consideration of a reconstructive procedure at a future date.
- If the rectal disease does become troublesome, it can usually be quite easily managed with steroid or 5-aminosalicylic acid (5-ASA) enemas. We do not advocate total proctocolectomy.
- Patients with toxic megacolon are often ill, septic, anemic, hypoalbuminemic, and nutritionally depleted at the time of presentation.
- These factors will predispose the patient to pelvic sepsis and an unhealed perineal wound if a rectal and perineal dissection is undertaken.
- Furthermore, total proctocolectomy is usually unnecessary to control the acute emergency, and it eliminates the possibility of a future reconstructive procedure.
- The blowhole operation has not gained wide popularity outside of the Cleveland Clinic.
- The rationale for performing this operation is that there is a higher mortality rate when a perforation occurs.
- Because the colon is often greatly dilated, the risk of iatrogenic perforation of the colon is significant.
- In addition, with mobilization, sealed perforations that may be present may be disrupted, causing fecal spillage.
- Turnbull et al. advocate the performance of a colostomy and an ileostomy to decompress the colon initially, with further surgical management at a later date once the acute process has settled.
o This procedure should certainly be kept within the armamentarium of any surgeon.
o However, with careful manipulation of the colon as previously outlined, the chances of perforation are kept to a minimum, and a subtotal colectomy has been our preference when possible.
- The blowhole procedure should be considered in acutely ill patients who have a hugely dilated and extremely friable colon.
- In addition, it should be considered in patients in whom a definite diagnosis of UC has not been made.
- It may also be considered in instances in which there is
o inadequate surgical assistance
o or when an operator is inexperienced in dealing with a severely diseased colon
o and with a high splenic flexure.
o Short transverse epigastric incision made over the dilated proximal transverse colon allows the colon to bulge into the incision
Historically, there is an approximately 25 to 30% mortality rate with medical management in toxic patients.
- This contrasts with an overall surgical mortality rate of 19%. However, it is difficult to compare the medical and surgical mortality rates, because often the patients who undergo surgery are sicker.
- The mortality rate is even higher when perforation has occurred.
- This report supports the contention that the medical treatment of toxic megacolon should be regarded almost exclusively as preparation for imminent surgery.
- Although rectal bleeding is a common symptom of UC, massive hemorrhage that necessitates rapid blood transfusion and emergency treatment is unusual, occurring in fewer than 5% of patients.
- Most frequently, it occurs in patients with acute, severe colitis.
- The treatment of these patients is usually twofold.
- First, treatment of the UC necessitates the
- use of high-dose steroids and other supportive measures.
- Second, the bleeding must be treated expeditiously and any coagulation abnormality corrected.
- In most patients, hemorrhage will subside spontaneously.
- It is unusual that the bleeding originates from a discrete site.
o The indication for surgery is not arbitrary but must be individualized for each patient.
o Once the decision is made to operate, the standard procedure has been proctocolectomy.
o However, this procedure, as previously mentioned, can be associated with higher mortality and morbidity rates than subtotal colectomy and it obviates the possibility of a reconstructive procedure in the future.
o Thus, in selected cases, one might consider a total abdominal colectomy, leaving a short rectal stump—sufficient to allow future reconstructive surgery.
o In most instances, this type of surgery will control the bleeding, although continuing massive hemorrhage can still occur in approximately 10 to 12% of patients.