Diverticulosis and Diverticulitis

Diverticulosis and Diverticulitis

Where is the large bowel located?

The large bowel (colon) "frames" the loops of the small bowel in the middle and lower abdomen and is divided into various sections:

The first section of the large bowel is located in the right lower abdomen, where the small bowel empties into it, forming a several centimetres long piece of the bowel (caecum). It has a blind end, and from this end, there is a thin appendage, the appendix.
Above this section, the ascending part of the colon (colon ascendens) begins. It rises upwards almost as far as the liver and then curves (right flexure of the colon).
Then follows the section of the large bowel, which runs horizontally from the right to the left in the upper abdomen (colon transversum, transverse colon). This part of the large bowel is kept in position by a fatty tissue in form of an apron and is grown together with the colon. It is called colic omentum, "great net". Reaching the spleen in the left upper abdomen, the large bowel again curves (left flexure of the colon).
The descending large bowel is now directed towards the left lower abdomen (colon descendens).

After this, the large bowel makes a double bend and is called colon sigmodeum, or just "sigma". Here, the large bowel ends and is followed by the last part, the rectum.
The rectum is 16 cm long and passes into the anus.

In the middle of this "frame of the large bowel", there are several large blood vessels, which come centrally from the aorta and are embedded in a protective layer of tissue and continue in a radial form to the small bowel and the colon. It is very important for the surgeon to know exactly which vessel supplies which section of the bowel. This must be the basis to perform good colon surgery.

How does the large bowel function?

Beside its function as organ of digestion, the complete colon still has to fulfil other important motorial and immunological tasks. Even if the stomach is empty, periodical ripples run down the smooth musculature of the colon from the gullet to the rectum and keep the small and large bowel continuously in motion, so that the chyme is transported onwards. In this process the movements of the loops of the small bowel are faster, so that the chyme passes through in a short time. At the same time, the mechanism of a fast passage counteracts a too high quantity of bacteria. In the large bowel, the time of passage is longer, so that the liquid chyme from the small bowel has enough time to be thickened. The main task of the large bowel is to withdraw great quantities of water from the liquid chyme and to restore it to the body. This objective is achieved by the motoricity of the colon, producing backward ripples of its loops. At the same time, there is a drastic rise of the quantity of bacteria, so that the components of the food can be broken up. The healthy colon has several mechanisms to bar off bacteria, and it produces certain proteins which have almost disinfecting abilities and which are located on the mucous membrane of the colon. If a chronic constipation is caused by eating food poor in fibre, by lack of physical activity, or by insufficient fluid intake, the pressure in the colon rises sharply, especially around the sigma of the large bowel. If this goes on for a long time, a permanent and local structural change of the intestinal wall takes place, which is called diverticulosis.

What is a diverticulosis and what is a diverticulitis?

What happens in this structural change? One can say in a simplified way that the intestinal wall consists of three layers: Inside the mucous, membrane is found that is followed by a firmer supportive layer, which again is surrounded by a mantle layer of muscles. Through the high pressure in the colon, which has already been mentioned, the mucous membrane is pushed to the outside like a finger of a glove in weak points of the muscles. If these outpocketings occur in many places of the sigma, they are given the name diverticulosis. It is the most frequent disease of the large bowel found in patients of more than 50 years. But more than 70% of the affected persons have no or very minor complaints. They complain at most of incidental pains or spasms in the lower abdomen at the left side, and, sometimes, diarrhoea and constipation take turns. But if stool and bacteria accumulate in these outpocketings, acute inflammatory complications may occur with ensuing bleedings, abscesses, or perforations of the intestinal wall. These complaints and symptoms characterize a diverticulitis, the secondary disease of the diverticulosis. Sometimes, these complications occur intermittently, resulting in the formation of scars in sections of the colon with recurring inflammations. They may increasingly narrow the lumen of the colon and cause an intestinal obstruction. In the case of an existent diverticulosis, a diverticulitis may occur at any time, but the resulting complications and the course it takes may be very different.

How do I recognize a diverticulitis?

"All my life I have been healthy. I only suffered always a little from constipation. I work as a business employee in an office, have to sit a lot and do not go in for much physical exercise. I eat at irregular times, usually a sandwich for lunch, and in the evening, I sometimes order a pizza. Two weeks ago, I suddenly suffered from violent diarrhoea, which did not especially worry me. The following days, it changed into complete constipation. Then again diarrhoea as well as abdominal pain particularly in the left lower abdomen followed, which, however, disappeared sometimes. One evening, I was tormented by such violent pain in the lower abdomen accompanied by high temperatures that I consulted a doctor."

This is a shortened version of a story that almost every doctor has heard. Light fever, diffuse pains left in the lower abdomen, and constipation alternating with bouts of diarrhoea in patients over 50 years make every doctor immediately pay attention. There are innumerable reasons for diarrhoea, and the doctor has to consider many differential diagnoses: inflammatory diseases of the colon as well as a classical abdominal influenza, worms, or other parasites. Especially in the case of elderly patients, who consult a doctor because of acutely setting in pain in the lower abdomen, a diverticulitis has to be taken into consideration. Only if there are diverticula in the colon, the patient may suffer from a diverticulitis. But neither the patient nor the doctor has this previous knowledge.

Necessary clarifications and diagnostic possibilities

The responsible doctor must first try to differentiate the symptoms of the disease by asking the patient specific questions: How often does diarrhoea occur and is it accompanied by mucus and blood? Does the stool cause pains or spasms in the lower abdomen? Does fever occur during such episodes? What are the habits of nutrition and life? Did the patient notice a massive loss of weight and a decline of fitness? Following this questioning, an intensive examination of the abdomen is carried out to localize the place, where the pains mainly occur. In the case of a diverticulitis, the examining doctor may be able to palpate same sort of "roll" in the left lower abdomen and cause a distinct pain on pressure. To verify the diagnosis, the doctor carries out a digital examination of the rectum. A blood examination completes this first questioning. The overall assessment of the symptoms furnishes information to the doctor about the manifestation of the diverticulitis, and it is the basis for further machine-aided diagnostical measures. What methods are available?

The abdominal sonography makes a basic orientation possible as well as the assessment whether there is free liquid in the abdomen or not.
The abdominal radiography (standing or lying) shows free air in the abdomen if the intestinal wall is destroyed.
A Computer Tomography with the rectum filled with contrast substance may furnish important information if there is suspicion of a local abscess.
A coloscopy may be used, if bleeding in the relevant section of the bowel is diagnosed, if other inflammatory diseases (e.g. ulcerous colitis) have to be ruled out, or if a non-surgical procedure is planned.

Depending on the course of the diverticulitis so far, age, physical condition, collateral diseases of the patient, and the results of the examinations, a decision is made which therapy should be used.

How can diverticulitis be treated?

The type of complication connected with diverticulitis determines whether a conservative or surgical therapy (if necessary: emergency surgery) is carried out. The criteria mentioned above have decisive influence on the choice of therapy, however. If there is "only" an inflammatory episode in question, without acute bleeding or destruction of the intestinal wall, the disease is treated conservatively. The most important measures to be taken are the immobilization of the bowel through abstinence of food (drinking allowed), alimentation via central venous catheter, and application of an antibiotic as well as of spasmolytic medicaments. Laxatives are not applied, nor are purgative measures of the rectum carried out because there is the danger of destroying the intestinal wall at the place of inflammation. When the inflammation subsides, the patient is again allowed to consume a high fibre diet that is not flatulent. If a diverticulitis is accompanied by a slight bleeding of the bowel from the inflamed area, one will first try a conservative treatment. So an enteroscopy is carried out and a haemostatic medicament is injected into the relevant location. In the interim period of health and after a good preparation (intestinal lavage), the affected section of the bowel can be removed (resection) in order to prevent another bleeding and other complications of diverticulitis. These so-called "elective" (planned) operations in the case of diverticulosis/diverticulitis are carried out in the following cases:

After at least one previous grave inflammation treated with antibiotics.
In the case of an inflammatory episode that does not heal, followed by an abscess in the tissue around the bowel.
Diverticula proved by enteroscopy.
In the case of re-occurring inflammations around the sigma and resulting stenosis or fistulae of the large bowel, an immediate operation is indicated.

In the following text the two surgical methods of resection are to be explained, which are used in planned interventions.

The open operation

The abdominal wall is cut layer by layer by a 10 - 15 cm long vertical skin incision from the navel down to the beginning of the pubic hair. The peritoneum is opened, and the visibility is maintained through the use of several big retractors, so that the complete lower abdominal cavity can be well surveyed. First, the inflamed section of the large bowel is dissected. Then, the surgeon decides how much of the affected large bowel must be removed. The next step is to mobilize the large bowel carefully from the peritoneum. Great care has to be taken of the left urinary duct, which passes through the tissue. The whole affected section of the bowel is exposed, and the supplying blood vessels are severed, so that the sigma can be well removed. As soon as this section of the bowel is accessible, it is cut on both sides of the diseased section with a special stapling device which cuts and sutures at the same time. Now there are two blind ends, which are joined by hand or with a special small suture device introduced through the anus into the bowel. This is followed by an inspection, whether there is any bleeding, and the installation of two silicone drains. Finally, the abdominal wall is closed layer by layer.

The laparoscopic operation

Nowadays, the minimally invasive surgery (keyhole surgery) prevails. Today, the laparoscopic method is first choice for the removal of bowel sections infested with diverticula if certain preconditions are met. The keyhole method is especially used with patients, who have a diagnosed diverticulosis and have suffered several attacks of diverticulitis. But in the case of complications like intestinal obstruction, perforation of the intestine, or an abscess, this method can often not be used any more. One must also refrain from this method during an acute attack of inflammation. In the minimally invasive surgery, gas is pumped into the abdominal cavity after a prick incision with a small trocar has been made. Through this incision, a sterilized tiny video camera is introduced into the abdominal cavity. Then, three more such small incisions are made, through which instruments can be inserted into the abdominal cavity. They are used to sever suspensory ligaments or adhesions, thus mobilizing the whole section of the bowel. The transection of the bowel below the diseased section is carried out with a laparoscopic stapling device as in an open operation. The section of the bowel with the diseased tissue is put into a small bag and pulled out through the access in the abdominal wall near the border line of the pubic hair. Into the remaining and healthy section of the bowel, the head of a stapling device is introduced, the bowel is sutured and placed again in the abdominal cavity. Now, the two ends of the bowel have to be joined together again.

A special suture device is introduced through the anus for this reason. It seizes the end of the bowel in the abdominal cavity and sutures it. Then, a test is carried out in order to find out whether the newly made connection has been tightly closed. Therefore, a blue liquid is injected through the anus into the bowel. If no blue liquid is seen seeping into the abdominal cavity, the connection is tight. The last step is to close the abdominal incisions layer by layer. If a diverticulitis causes a destruction of the intestinal wall, a bleeding that cannot be controlled or an extensive infection through faeces in the abdominal cavity, the patient must undergo an emergency operation. Because of the emergency, but also because of the danger of perforation (defect) of the intestinal wall, an intestinal cleansing before the operation cannot be carried out. This might, however, causes a worse wound healing in the place where the bowel is sutured. In this situation, the surgeon has to decide whether he is going to join the ends of the bowel together again after having removed the diseased section of the bowel or not. The surgeon has two options here:

He removes the diseased large bowel and conducts the upper end temporarily through the abdominal wall to the outside (colostoma) and closes the lower end (Hartmann operation). The continuity of the bowel is therefore not restored for the time being. The patient can recover and one has time to wait until the inflammation in the lower left abdomen has stopped. After three months, another operation follows, in which the colostoma is relocated and the two ends of the large bowel are joined together again.
After the resection, the surgeon joins the two ends together again, but relieves this section by running off the stool through a stoma installed further up. In this case, one would also, after the infection has disappeared, relocate the stoma in a second operation.

What happens after the treatment?

Patients with a grave course of disease are transferred for supervision to the intensive care unit after the operation. There, they receive further antibiotics, a balanced infusion therapy, and sufficient pain killers. The most important blood factors are controlled as necessary. If the patient's condition is stable again, he is transferred to the normal ward after a short time. Normally, the patients are allowed to drink in sips after 2 - 3 days. As inflammations in the area of operation are frequent, the surgeon prefers to be conservative and restrictive to avoid stress on the new suture of the bowel. That means that food ingestion is slowly started at about the 4th day with the intake of liquid food, beginning with soup and pudding. At the same time, the patient has to get up and move around a little and receives respiratory care. On the tenth day, the sutures of the skin are removed. Now, the patient can leave the hospital; if there are no complications, he can leave even earlier. Patients provided with a stoma during the operation learn how to handle the relevant hygiene and materials under the guidance of a stoma advisor. After a successful operation without complications, patients do not have to observe special regulations. It may take a certain time until a normal and soft stool will be the rule. It is important to eat food rich in dietary fibre, to drink enough and to go in for sufficient exercise. A restrictive diet must not be observed, however.

History

Still 150 years ago, about two thirds of the patients with intestinal hernia operation died. Even after smaller interventions like the amputation of toes or fingers, 10% of the patients died. The reasons for this high mortality were lacking anaesthesia, antisepsis, and the shock problem. Shock can be caused by severe loss of blood or bacteria that seeped in and may result in death. But then, pioneering discoveries were made, constituting the firm foundation for every great abdominal surgery. Horace Wells realized the first narcosis in 1844 using laughing gas, and in 1901, Karl Landsteiner discovered the blood groups of the human being. This furnished the possibility to perform blood transfusions during great surgical operations and to successfully treat the blood-loss shock. However, the greatest achievement was the finding of Ignatz Philipp Semmelweiss that the wound infections at that time were mostly fatal, especially the childbed fever, because of lacking hygiene of hands and instruments. Until then, an intensive disinfection of the hands was entirely unknown in hospitals. Without knowing it, one carried the bacteria from one patient to another. Unfortunately, Semmelweiss was too progressive for his time, so that his appeals for a disinfection of the hands with carbolic acid, even if proved effective, were at first not taken seriously by many doctors, among them the famous discoverer of the bacteria, Luis Pasteur. It was the surgeon Joseph Lister in Glasgow, who had heard of Semmelweiss' ideas and used them with success in his hospital in 1867. The hands of the surgeons were washed with soap containing carbolic acid before the operations, and a carbolic solution was sprayed over the area of surgery during the operation. This reduced the number of fatal complications after operations considerably. Because of these findings, operation theatres were built that could only be entered with mouth guard and head bandage. This was the reason why the first great and aseptically carried out abdominal surgeries were much more successful from 1880 onwards. An example for the sense of a new era in abdominal surgery, due to the new conditions mentioned, is the work of the surgeon Ulrich Kroenlein, who worked and taught at the University Hospital at Zurich since 1881. He put the new sanitary ideas into action in his hospital by having the floors tiled, by removing bedsteads made of wood, and by building a new surgery for instruction in the form of an amphitheatre. As one of the first surgeons, Kroenlein operated cases of acute appendicitis and worked on the therapy to fight purulent peritonitis, which occurred after injuries of the bowels. In order to avoid peritonitis that occurred because of bad sutures of the bowel (anastomosis), two other famous surgeons of that time made an effort to develop new suturing techniques in abdominal surgery: Theodor Kocher and Vinzenz Czerny. Theodor Kocher writes in 1894: "The intestinal resection has become an extraordinarily important and comparatively frequent surgical intervention, by which the surgeon can save many lives otherwise being considered lost if he carries it out correctly." At the same time, he introduced his running perineal suture. This is why Sir Ernest Miles was able to carry out the first radical abdominoperineal resection of a rectum carcinoma, a very great intervention, in which the colon and the rectum are completely removed.