Surgical Management of Crohn Disease in Children


Obstruction

Bleeding

Perforation

Fistula

Phlegmon

Abscess

Drug allergies

Drug resistance

Perineal disease

Urologic complications

Progression

Growth failure



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Fig. 41.1
Distribution of pediatric Crohn disease (de Bie et al. [10])


Isolated Crohn disease of the foregut is relatively rare [11] and rarely requires surgical intervention. In contrast, terminal ileal and colonic disease account for the vast majority of surgical interventions in the pediatric patient. Some require urgent operation, while most are more elective in nature. The most common complications leading to a surgical intervention are obstruction, abscesses, fistulas, and failure or intolerance of pharmacological treatment [1214].

The indications for surgery have evolved somewhat as medical treatments have improved. A study examining surgical indications in the period from 1970 to 1990 compared to the period from 1991 to 1997 revealed that active disease as an indication for surgery decreased from 64 to 25% of cases, while chronic stricture increased from 9 to 50% of cases. In addition, the time from diagnosis to initial operation increased from 3.5 to 11.5 years [15] suggesting that medical therapy has been successful in altering the course of disease but not necessarily preventing ultimate progression in many cases. Fortunately, the shift to less emergent operation likely reduces the morbidity associated with a surgical intervention.

Absolute indications for surgery are rare, and many patients present with multiple relative indications rather than an acute precipitating event. In a large cohort of adults with Crohn disease, the decision to proceed with surgery was distributed as follows: failure of medical management in 220, obstruction in 94, intestinal fistula in 68, mass in 56, abdominal abscess in 33, hemorrhage in 7, and peritonitis in 9 [16].

As our understanding of inflammatory bowel disease has increased, it has become clear that there are different variants of Crohn disease, and some phenotypes are more likely to require operative intervention. The age at diagnosis has an impact on disease characteristics and propensity to progress with younger patients having more extensive and more aggressive disease than adult-onset patients [17]. The complex associations of genetic and epigenetic alterations with specific phenotypes are beyond the scope of this chapter, but our ability to predict patterns of disease and response to therapy continues to improve. As our understanding of the relationship between genotype and phenotype grows in the future, it may be possible to target specific patient populations for specific types of surgical intervention based on response rates and specific disease characteristics.

The indications for surgical intervention in the pediatric population differ from those in adults in many cases. Mechanical complication of obstruction and perforation is the same, but the impact of medical therapy on growth and development is unique to the pediatric population [18]. In as many as 50% of pediatric patients, the indication for surgery may be failure of medical therapy with growth retardation rather than obstruction or other mechanical complicationsl [19]. In one study of children who had received extensive medical and/or nutritional treatment before surgery, 26 patients underwent intestinal resections. The indication for surgery was chronic intestinal obstruction in 13 cases and chronic intestinal disability leading to growth failure in 13 cases [20]. Furthermore, the timing of surgery for growth issues is critical in the adolescent. Surgical intervention must occur well before epiphyseal plates close to allow sufficient time for subsequent catch-up growth following the operation [21]. Surgical therapy is associated with significant catch-up growth in 6 months following operation in patients with treatment-resistant disease [22].

Fortunately, surgical treatments have evolved along with medical therapy, and current surgical procedures are safer and less invasive than at any time in the past. Surgery has progressed from a treatment of last resort for life-threatening complications to therapy for use in conjunction with medical interventions to maximize the patient’s quality of life. While the specter of short bowel syndrome must be kept in mind, elective procedures to treat the complications of Crohn disease can be accomplished safely and effectively [23]. While medical therapy may one day render surgical therapy unnecessary, at present, the surgeon remains an integral part of the treatment team for patients with any inflammatory bowel disease and Crohn disease in particular.



Surgical Emergencies


Patients who develop either perforation with diffuse peritonitis or obstruction that is unresponsive to medical management are rare but may require an urgent operation. The operative goal in this situation is to control sepsis and decompress the intestine with as little risk to the patient as possible. In cases of perforation where the process is localized, percutaneous drainage and antibiotics may convert an acute situation into a more controllable elective intervention. When laparotomy is undertaken in the acute setting, the peritoneal cavity may be very hostile with inflammatory adhesions, fistulas, friable bowel, and diffuse peritonitis making extensive dissections and primary bowel anastomosis ill advised. Rather than proceed with extensive surgery, often the most prudent approach is to divert the fecal steam with a proximal ostomy [24]. Resection of the involved intestinal segment may be considered when technically possible, but proximal diversion without addressing the actual diseased bowel may be the safest option in severe cases.

Proximal diversion with an ileostomy is not without risk. Ileostomies are associated with significant complications at the ileostomy site in addition to the accompanying challenging body image and social stigmata in teenagers [25]. The risk of a diverting ostomy becoming permanent is significant. In a recent pediatric series from the Cincinnati Children’s Hospital Colorectal Center, 11 pediatric patients underwent diversion and 8 (73%) had the ostomies reversed. However, three patients required re-diversion leaving only 45% of the original group without a permanent diversion (unpublished data presented at the 2012 meeting of the American Pediatric Surgery Association).

Once the intra-abdominal sepsis is controlled and the inflammatory adhesions are allowed to resolve for 6–8 weeks following emergent ileostomy, a more definitive procedure with ostomy closure can be considered. Although no one, especially teenagers and their parents, wants an ileostomy, attempting an extensive dissection or bowel anastomosis in the face of severe inflammation can result in life-threatening complications and potential loss of large segments of small bowel.

A complete bowel obstruction without accompanying sepsis that does not respond to medical therapy may also require an acute surgical intervention [26]. In a stable patient, aggressive medical management should be attempted to resolve the obstruction before committing to taking a patient to the operating room. This is especially true in cases involving difficult to treat intestinal segments like the duodenum where avoiding any surgical intervention is desirable if possible [27]. If the obstruction fails to resolve or evidence of bowel compromise is present, operation must be undertaken without the ability to prepare the bowel for primary anastomosis. At surgery the bowel is often inflamed and friable, and although a definitive resection with reanastomosis may be possible, the patient and family must be prepared for a diverting ileostomy to avoid the risks of breakdown of an attempted primary bowel anastomosis.

Patients that have had multiple previous abdominal operations may be particularly challenging because of preexisting adhesions and scar tissue. Studies suggest that as many as half of the patients undergoing reoperative surgery will require ileostomy formation [28]. In many pediatric patients, this is less of an issue because often patients are making their first trip to the operating room, but one should never hesitate to perform a temporary bowel diversion when primary anastomosis may be unsafe.


Elective Surgery


The indication for surgical intervention is more commonly not emergent, and the timing of the intervention requires the careful consideration of the surgeon, the gastroenterologist, and the family. The typical indications for surgery include failure of medical management, stricturing disease with near obstructing lesions, fistulas, and complications related to the side effects of medical therapy.

The preoperative evaluation usually includes both endoscopic and imaging studies. Traditional imaging involves contrast enemas and/or upper gastrointestinal series with small bowel follow-through. More recently, magnetic resonance enterography has been utilized to provide a more complete assessment of the entire gastrointestinal tract [29]. Some recent evidence suggests that CT enterography may provide superior imaging [30] but the differences are not dramatic, and the experience of the radiologist is probably more important when deciding between the two studies. Whichever method is chosen, enterography offers the advantage of cross-sectional imaging of the entire bowel wall rather than being limited to assessing luminal disease. This allows for more accurate surgical planning and facilitates discussions with the patient and family regarding the operative approach.

Efforts should be made to control intra-abdominal sepsis through drainage of abscess and treatment with antibiotics prior to surgery along with supporting the nutritional status of the patient. Percutaneous abscess drainage with prompt resumption of immunotherapy has been associated with avoidance of bowel resection in the pediatric Crohn disease population [31].

Methods to reduce the risk of surgical site infections (SSI) including anastomotic leaks, intra-abdominal sepsis, and wound infections have been extensively studied and remain controversial. The use of intravenous antibiotics, enteral antibiotics, and mechanical bowel preparation has all been advocated for colorectal procedures. As with many pediatric surgical procedures, most of the data comes from the adult surgical literature. The evidence pertaining to the prevention of SSI has recently been evaluated and reported by the Outcomes Committee of the American Pediatric Surgical Association [32].

The presence of a stricture alone is not an indication for operation. Areas of diseased bowel that do not present a mechanical impediment to the flow of the intestinal contents do not require intervention. However, significant chronic obstruction is suggested by dilation of bowel loops proximal to the diseased area (Fig. 41.2). These changes signify a possible impending complete obstruction, and elective resection prior to that allows the opportunity for bowel preparation and resection with primary anastomosis rather than a two-stage procedure requiring temporary diversion with subsequent ileostomy closure. Entero-entero fistulas, chronic phlegmon, and enterocutaneous fistulas are other mechanical indications for operative intervention which can be dealt with after careful radiographic studies to delineate the anatomy and preoperative patient preparation.

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Fig. 41.2
Barium contrast study demonstrating a segmental distal ileal stricture

Fistulas to the urinary tract with recurrent urinary tract infections may not constitute an urgent indication for operation, but continued soiling of the urinary tract could result in progressive renal dysfunction arguing for earlier rather than later intervention in these situations. Although some patients will respond to medical therapy, vast majority of patients will require surgical intervention [3336]. Enterovesical fistulas are treated with takedown of the fistula and closure of the bladder, while ureteral fistulas may require resection with reanastomosis or reimplantation of the ureter.

Finally, progression of the disease with persistent symptoms despite maximal medical therapy may also be the impetus for considering the surgical option. Regardless of the indication, the philosophy of therapy remains the same. The surgical procedure must be tailored to the individual patient with an eye toward preserving all possible small bowel length while providing the most effective palliation of the presenting complication of the Crohn disease. Surgical intervention in patients with progressive or chronic symptoms related to stricturing or fistulizing disease in the abdomen is effective in relieving symptoms and can minimize absence from school and improve overall well-being when compared to nonoperative therapy [37].


Surgical Therapy


The procedure performed at the time of operation depends on the clinical situation and extent of the disease. As mentioned previously, in a patient that is acutely ill with sepsis or complete obstruction, simple diversion may be the most appropriate response. However, in most patients a more definitive procedure is performed. In pediatric patients with stricturing disease, the terminal ileum is the most common site involved. Often the disease extends up to include the ileocecal valve, and the most common approach is bowel resection extending from the proximal extent of the disease in the ileum to the ascending colon, which is usually uninvolved. Bowel continuity is restored with a primary anastomosis.

In an effort to preserve as much bowel length as possible, only gross disease is resected since recurrent disease may require additional surgery, and bowel length may be shorter than normal in patients with Crohn disease leaving less margin for resection before developing issues with poor absorption [38]. The actual technical aspects of the procedure vary somewhat by surgeon and are largely a matter of training and experience. Bowel resection is carried out in the standard fashion with no need to obtain clear margins or mesenteric lymph nodes as might be required for a cancer operation. The only technical aspect of the procedure that may impact outcome is the manner in which the bowel is anastomosed.

There are a number of techniques for reanastomosing bowel with the most surgeons performing either a hand-sewn end-to-end anastomosis or a side-to-side, functional end-to-end stapled anastomosis. There is some evidence to suggest that a stapled anastomosis may reduce the time to recurrence in patients with Crohn disease [3947]. The reason for this is unclear and may have to do with the diameter of the resulting anastomosis or the nonreactive nature of the staples. Alternatively, it may have more to do with the anatomic orientation of the anastomosis rather than the manner in which the bowel is re-approximated [48]. The other reported benefit of a stapled anastomosis stems from data to suggest that anastomotic leaks and intra-abdominal abscesses are less common with the stapled anastomosis in some series but not in others [43, 4952].

Complications following bowel resection and anastomosis in patients with Crohn disease are common and are most often infectious in nature. Wound infections are most common and occur in as many as 20% of patients, while more serious intra-abdominal infections related to anastomotic leak occur in 3–10% [43, 53]. Wound complications are treated with local care, while anastomotic complications may require reoperation with revision or temporary diversion with an ostomy.


Stricturoplasty


Diffuse small bowel disease with skip lesions or strictures that do not involve the ileocecal valve allows for some additional options in surgical treatment. Short segments are often resected with primary anastomosis when it represents the only area of disease. However, multiple short segments or longer segments up to 20 cm in length may be amenable to stricturoplasty rather than resection in an effort to preserve bowel length.

The technique entails a longitudinal enterotomy through the strictured segment with closure in a transverse fashion to relieve the obstruction (Heineke-Mikulicz stricturoplasty) (Fig. 41.3). While it seems somewhat counterintuitive to leave the diseased bowel in situ, the results following this operation are quite good even when applied to multiple strictures in the same patient [54]. Surprisingly, the rate at which recurrent disease occurs at the stricturoplasty site is low [55], and the technique has been used for many years with results from long-term follow-up studies supporting its use [56]. Recurrence rates following stricturoplasty are on the order of 15% at 2 years and 20% at 5 years [57].

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Fig. 41.3
Heineke-Mikulicz enteroplasty

There are a number of technical modifications of this technique that allow for longer segments to be preserved while relieving obstruction [5862]. In a study of 102 patients undergoing a nonconventional stricturoplasty for a longer segment of the intestine, there were 48 ileoileal side-to-side isoperistaltic stricturoplasties, 41 widening ileocolic stricturoplasties, and 32 ileocolic side-to-side isoperistaltic stricturoplasties, which were associated with Heineke-Mikulicz stricturoplasties in 80 procedures or with short segmental bowel resections or both in 47 procedures. The postoperative complication rate was 5.7% which is consistent with the complication rate from the more common Heineke-Mikulicz stricturoplasty. The 10-year clinical recurrence rate was 43%, and the recurrence rate at the previously affected site was only 0.8% [60]. In another study long-segment stricturoplasty (>20 cm) was reported to have recurrence rates that are not significantly different than that for shorter-segment disease. Recurrence rates were 20–35% at 3 years, 50% at 5 years, and 60% at 10 years with no difference in complications between the groups [59].

In some very difficult situations such as long duodenal strictures, other modifications of the stricturoplasty technique can be applied. In one such case, a jejunal patch was used to successfully relieve the obstruction and avoid intestinal bypass in a patient with a difficult duodenal stricture [63].


Laparoscopy


The most recent advances in surgical treatment of intra-abdominal complications of Crohn disease have been the application of minimally invasive surgical techniques. As with many of the other conditions to which laparoscopic techniques have been applied, multiple studies have demonstrated a decrease in hospital length of stay, more rapid return to work, less postoperative narcotic use, and improved cosmetic results. Similarly, multiple studies of laparoscopic techniques applied to surgery for Crohn disease in children and adults have also suggested shorter hospital stays, decreased need for parenteral narcotics, and faster return to a regular diet [6473]. However, a recent Cochrane analysis has shown no difference in length of stay or duration of ileus [74], and the morbidity of the laparoscopic approach is equivalent to open surgery [75]. Thus, although the benefits of the laparoscopic approach may be limited to improved cosmesis at the expense of longer operating time, there is a trend toward increased use of minimally invasive techniques, and the outcomes are at least equivalent to open surgery.

The techniques employed often use laparoscopic exploration of the abdomen with mobilization of the diseased bowel segment. Various sealer/cutting devices facilitate taking the mesentery of involved segments without additional blood loss and stapling devices allow for dividing the bowel at the margins of disease. Anastomosis may be carried out extracorporeally after the diseased segment is delivered from the abdomen through a small incision or intracorporeally using the laparoscopic stapling devices. These techniques can also be incorporated into the single-site surgical approach to achieve “scarless” operations [76] although the benefit is purely cosmetic and the outcomes have not been tested. Use of the surgical robot has also been reported with the possible benefit of reducing conversions to an open operation but no difference in other surgical morbidities [77].

Although complicated disease involving fistulas or phlegmon was considered a relative contraindication to the laparoscopic approach, many cases are now handled by experienced surgeons without an increase in complication rate [7883]. One potential benefit of the laparoscopic approach is a reduction in postoperative adhesion formation. This carries added importance in the Crohn populations where disease recurrence is more the rule than the exception and reoperation is often necessary. Reduced adhesions facilitate subsequent operations [84] and theoretically lower the risk of injury to the bowel and ureters. Approaching recurrent disease laparoscopically is also feasible without an increased complication rate [85, 86].

In the long run, patients’ quality of life does not appear to be impacted by the technique used at the time of surgery [86, 87]. However, the advantage of the minimally invasive approach likely extends beyond quality of life measurements. Reduced intra-abdominal adhesion formation, possible faster resumption of full enteral nutrition, and perhaps less psychological trauma related to body image issues are all of particular significance to the pediatric patient population.


Colonic Disease


Crohn colitis requires a different approach than for small bowel disease. Colonic disease is traditionally regarded as being more aggressive, and the colon is not necessary for the nutritional function of the intestinal tract, so some advocate subtotal colectomy rather than segmental resections when colonic involvement requires surgical intervention. However, segmental resection offers the opportunity to preserve colonic function and avoid or delay the potential for permanent ileostomy and has become the more common approach [15]. Fewer symptoms, fewer loose stools, and better anorectal function have been reported following segmental resection, and the re-resection rate did not differ from patients undergoing subtotal colectomy [88, 89]. Conversely, patients with pancolitis or severe distal colonic disease have been reported to have longer disease-free intervals [90] and wean from chronic medications more often when treated with subtotal colectomy or proctocolectomy when compared to those undergoing segmental resection. However, these patients also had a higher incidence of permanent diverting ileostomy [91, 92] suggesting that segmental resection for pediatric patients with colonic Crohn disease is preferable when possible. Laparoscopic techniques are possible and show similar advantages of those described in small bowel resection [93].


Perineal Disease


Approximately one third of patients with Crohn disease will develop perineal or rectal manifestations of the disease [94]. Patients presenting with perineal disease tend to have more aggressive disease with higher rates of both perineal and intra-abdominal operations [95].

Fistulizing perineal disease is an area in which surgical intervention has classically been avoided given the risk of nonhealing wounds and incontinence. More recently, however, the use of early surgical evaluation has been found to provide important information to help guide the medical management. While fistulotomy and incision and drainage of local abscesses were fraught with long-term complications in the past, the use of new biologic agents such as infliximab has rendered early surgical intervention not only safe but necessary for rapid control of the disease.

Medical therapy for perineal disease has been greatly improved with the advent of biologic agents yet more than half ultimately require surgical procedures [96]. Two controlled trials support the efficacy of infliximab in achieving closure of perineal fistulas [97], and the combination of infliximab and surgical treatment of fistulizing perineal disease can result in marked improvement of perineal disease which is superior to infliximab alone [98100]. Conversely, infliximab treatment does not prevent the need for surgery for fistulizing Crohn disease [101].

Treatment algorithms in pediatric inflammatory bowel disease centers have evolved to include an aggressive surgical approach early. Examination under anesthesia is particularly useful in the pediatric population. Comprehensive rectal examination is often difficult in the clinic setting in younger patients that are unable to cooperate fully with the exam. General anesthesia in the operating room provides the ideal environment to carefully evaluate the extent of disease with delineation of fistula tracts, abscesses, and rectal strictures. A complete assessment of the extent of the disease is important to help guide medical therapy.

Once the extent of disease is determined, therapeutic measures can be performed during the same anesthetic. If fistulae-in-ano are present, they can be probed to ascertain the anatomy. Superficial tracts are treated with fistulotomy, while for more complex tracts a non-cutting seton placement is placed.

Initial surgical treatment may improve the response to subsequent pharmacologic therapy. Local infection can be controlled, strictures dilated, and complex fistulas delineated and controlled with seton placement. Following initiation of treatment with infliximab, the seton is removed to allow the fistula tract to close. Abscesses are drained and strictures can be sized and dilated.

Unfortunately, long-term control of perianal disease remains a challenge, and diverting colostomy may be necessary to gain control of the problem in pediatric patients. In adults, as many as 20% of patients with severe perianal disease proceed to proctocolectomy with permanent ileostomy [94].


Rectal Strictures


Low rectal and anal strictures caused by chronic fibrosis from chronic inflammation can be successfully treated with transanal dilations [97]. Younger pediatric patients may require dilations under anesthesia on a regular basis, while older patients will tolerate dilations in the office or at home. Incontinence can result from overdilation of rectal strictures or operative damage to the muscles during fistulotomy, but it is often difficult to separate the impact of the dilations relative to the underlying disease process. Tight irregular strictures longer than 3–4 cm without a clear lumen are a relative contraindication to dilation because perforation of the rectum is possible, particularly in small pediatric patients. Initial dilation in the operating room guided by fluoroscopy may reduce the risk of subsequent outpatient dilations. Treatment with dilations may be needed for many months, and ultimately the result is dependent on systemic control of the disease process. Strictures that do not respond to chronic dilations may eventually require a diverting colostomy. The combination of anal stricture and colonic Crohn disease ultimately leads to fecal diversion in more than 50% of patients [102].

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Nov 20, 2017 | Posted by in GASTROENTEROLOGY | Comments Off on Surgical Management of Crohn Disease in Children

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