Crohn’s disease is an inflammatory condition of the bowel that can affect the gut tube anywhere from the lips to the anus. The commonest site of pathology, however, is the small bowel, and this is indeed the focus of most surgical therapy. Other sites, such as the colon and the duodenum, present unique challenges.
Crohn’s disease is not curable with an operation. Therefore, the goal of surgical therapy is to manage complications of the disease, or improve the patient’s quality of life. Thus, decision making regarding surgery is a complex exercise, requiring data and participation from multiple physicians and often, many diagnostic studies. Because the disease has a high recurrence rate, surgeons frequently have long-term professional relationships with Crohn’s disease patients and often operate on the same patient multiple times.
There is perhaps no other disease in which the teamwork between the surgeon and the gastroenterologist is so important. Thus, the first step in preoperative examination is to understand the gastroenterologist’s opinion regarding the state of the patient’s disease. This, of course, is most effective through direct communication.
Preoperative radiology examination has taken on additional importance with the advent of minimally invasive surgical approaches to Crohn’s disease. Since the surgeon’s fingers may not be feeling all aspects of the bowel, knowledge regarding the portions of bowel that are likely to be diseased is particularly important.
The mainstay of preoperative examination is the contrast gastrointestinal radiograph. Most commonly this is an upper gastrointestinal and small bowel follow-through study. Even in patients with Crohn’s disease limited to the colon, the small bowel should be studied to avoid surprises in the operating room. Consultation with the radiologist performing the study will arm the surgeon with nuances regarding the disease and the anatomy that are not obtainable from the written radiology reports. Computed tomography scanning complements the luminal study, because it provides information regarding thickening of the bowel wall and the mesentery. This is particularly true with the current ability to synthesize three-dimensional imaging from Computed tomography scan data. Computed tomography scans also provide important information regarding the possible involvement of other organs by fistulizing Crohn’s disease. For instance, a Computed tomography revealing a dilated ureter on the right hand side likely means that local inflammation has created a partial ureteral obstruction. This would be an important preoperative warning that dissection in this region will be dangerous, and that placement of ureteral stents should be planned.
All patients undergoing abdominal surgery for Crohn’s disease should have the colon examined, preferably via colonoscopy in the recent past, even if no colonic involvement is suspected. In general, visual inspection of the outer colonic wall at surgery will not necessarily reflect Crohn’s disease within the lumen. Early mucosal Crohn’s disease in the colon can look quite normal from the outside. For patients anticipating surgery with known involvement of the colon, colonoscopy is particularly important to map out the diseased and nondiseased segements, and to plan the appropriate procedure.
For most patients, a small bowel series, Computed tomography scanning, and colonoscopy will suffice. However, additional studies to answer specific questions can be very helpful. For instance, a white blood cell tagged scan can assess the degree of active inflammation in tissues affected by Crohn’s disease. Magnetic resonance imaging has also been reported to be helpful in this regard, but in our experience does not add significantly to the data that good Computed tomography scanning (sometimes with water for contrast rather than normal contrast agent) provides. If the patient has symptoms referable to the upper gastrointestinal tract, this should be evaluated by endoscopy. The duodenum can be afflicted with primary Crohn’s disease involvement, or it can suffer involvement by proximity to a diseased hepatic flexure of the colon, or even an adjacent loop of diseased small bowel.
Careful preoperative preparation can make the difference between a successful Crohn’s disease operation and a disaster, particularly in the setting of complex severe disease. Bowel preparation with purgatives and oral antibiotics is particularly important. We bowel prepare patients with colonic disease, and those with small bowel disease, as many of these patients have dilated partially obstructed bowel with stagnant stool predisposed to bacterial overgrowth. Patients with high grade obstruction are prepared with an extended preoperative period of a clear liquid diet (to include tube feeding formula if the duration is long), with administration of the routine oral antibiotics. Partially obstructed patients often need to undergo their bowel preparation in the hospital with the support of intravenous fluids and antiemetics.
TABLE. Preoperative Preparation for Crohn’s Disease Surgery
|Consultation with gastroenterologist|
|Consider possible additional Crohn’s disease sites|
|Prepare for (possible) stoma|
When preoperative studies reveal significant intra-abdominal inflammation, we will often elect to treat the patient with parenteral support and bowel rest for 4 to 8 weeks. Physical examination of the abdomen can be a guide as to whether bowel rest will be of value. If the abdomen is soft and pliable to palpation, the tissues will likely be safe to dissect. If, however, the abdomen is hard and sclerotic, either locally or throughout the abdomen, the dissection is likely to be difficult. In this case, the prolonged bowel rest might avert operative complications. Parenteral support is, of course, vital in the patient with moderate to severe malnutrition. The Crohn’s disease patient with high grade obstruction and severe inflammation is a case, in our judgement, where parenteral support is superior to enteral support. Nutritional support increases the number of patients who can be considered for a laparoscopically assised procedure.
We are beginning to have some experience with inflixamib (Remicade) in the setting of surgery for inflammatory bowel disease. It appears that patients with aggressive fistulizing Crohn’s disease may best be prepared for surgery by a period of treatment with Remicade to minimize inflammation and “cool off” areas of extensive fistulization. Thus far, operating upon patients recently treated with Remicade does not appear to have significant risks. The experience is early, however. A few of these patients with fistulization have been left on inflixamab postoperatively
Patients who will or might need a stoma, be it temporary or permanent, need to counsel with an enterostomal therapy nurse. The nurse provides an appropriate site for the stoma, and follows the patient through their adjustment to a stoma devise.
Resection is the commonest procedure performed for Crohn’s disease. In most patients the length of diseased bowel is short, and there is more than adequate residual bowel. Our practice is to perform an anastomosis in two hand-sewn layers. We recognize that there is adequate data to support the use of stapled anastomoses. However, the degree of control when the surgeon places every stitch is comforting in the setting of Crohn’s disease where there is often inflamed local tissue, the presence of steroids, and nutritional issues. Stricturoplasty is an option in which the diseased bowel is not removed, but rather opened in a longitudinal fashion and closed in a transverse fashion. This has great utility when the strictured segment is short, and when there are multiple effected areas. However, when the diseased segment is long, stricturoplasty becomes similar to bypass, a procedure abandoned long ago for good reason.
A fistula can be between two portions of Crohn’s disease bowel, in which case both portions of diseased bowel should be removed (eg, diseased terminal ileum fistulizing to diseased sigmoid colon). More commonly the fistula is between diseased bowel and a nondiseased “innocent” organ or portion of bowel (eg, terminal ileum fistulizing into the bladder). In this instance, the surgical objective is safe division of the fistula while avoiding damage to the innocent tissue.
This is often a point at which a laparoscopic operation may need to be converted to an open one. In all instances the innocent tissue should be carefully examined, and repaired or removed if necessary. The genitourinary system is a frequent target of fistulization, and intraoperative consultation with appropriate specialists, if available, can be enormously helpful. Figure 68-2 shows Crohn’s disease that has fistulized to the skin surface. Surgical correction of this severe situation takes careful planning, and great patience in the operating room.
The surgeon must also anticipate the need for additional procedures at the time of surgery. For instance, if significant portions of the bowel are to be removed, the gall bladder should probably be removed at the same time.This is particularly true if the patient is likely to need long term parenteral support. If long term nutrition is likely to be necessary, the placement of a gastrostomy or jejunostomy might also be contemplated.
Crohn’s disease of the colon and rectum presents unique challenges. Determining the extent of disease in the colon is a challenge addressed above. In patients with skip lesions throughout the colon, the surgeon must decide whether it is worth attempting to salvage spared regions of the colon. Since the colon is not essential for nutrition, there is a tendency to be more aggressive with resection. Multiple anastomoses in the colon are worth avoiding, as they have a greater chance of anastomotic leak. However, since diarrhea is a persistent source of suffering for Crohn’s disease patients, salvaging colon for fluid absorption certainly has merit.
In the small bowel, the portion of diseased bowel can be removed and re-anastamosed. In the low rectum, this is usually not possible, leaving permanent colostomy as the only surgical option. Some centers have reported some success with restorative proctocolectomy (with ileo anal pouch anastomosis) in selected patients with Crohn’s disease limited to the colon. We have had patients who have undergone restorative proctocolectomy for ulcerative colitis who later were found to in fact have Crohn’s disease. The extremely difficult management problems with pouch function and pouch fistulas in these few patients have prevented us from offering restorative proctocolectomy to patients with even a hint of Crohn’s disease.
Rectal Crohn’s disease
Rectal Crohn’s disease is a particularly challenging problem. These patients suffer with pain, chronically draining fistulas, strictures, and sometimes all of the above. When Remicade fails in this group, the surgical options are few. Patients with persistent rectal structuring can be maintained for a time with intermittent dilatation under heavy sedation or anesthesia. It is extremely important in these patients to biopsy tissue in the region of any stricture any time the surgeon manipulates the tissue, as an occult adenocarcinoma can arise in these strictures. In patients with these problems, in our experience, local surgical procedures usually simply palliate the condition until the patient recognizes the need for relief in the form of a stoma. When they do so, the following two options exist: (1) proctectomy and permenant stoma or (2) stool diversion by the creation of a theoretically temporary stoma while leaving the diseased rectum in. In this latter instance, the patient is often hoping for a future breakthrough in medical therapy that will allow takedown of their stoma. When this option is chosen, the blind remaining rectum must be regularly surveyed by sigmoidoscopy and biopsy, as adenocarcinma can arise.
The duodenum, particularly the first and second portion, is another segment of gut where simple resection is not possible. In unique instances, a Whipple procedure may be appropriate as a means of removing badly diseased Crohn’s disease duodenum. The more common and less morbid approach is to perform a bypass in the form of a retrocolic gastrojejunostomy, usually accompanied by a vagotomy
Surgical treatment of Crohn’s disease does not “cure” the disease, but the majority of patients requiring medication for Crohn’s disease will need surgical treatment. The appropriate treatment of these patients is challenging. It requires careful thought, careful planning, and extensive consultation between surgeon and gastroenterologist.