IN THE NAME OF GOD

1. IN THE NAME OF GOD ENTERIC FISTULAS

2. ENTERIC FISTULAS • represent a second group of complex intraperitoneal infectious processes. • Mortality remains high, between l0-30% in recent series. • largely due to the frequent complications of sepsis and malnutrition. • Electrolyte imbalances, as a third key factor leading to mortality

3. CLASSIFICATION • Classified by: • the anatomy of the stnrctures involved • the amount and composition of drainage • the etiology responsible for their formation • In addition to classification,these distinctions may provide important prognostic information about the physiologic impact of fistulas and the likelihood that they will close without surgical resection,the principal decision confronting the responsible surgeon.

4. ETIOLOGIC CLASSIFICATION • Enterocutaneous fistulas result from several processes: • (1) diseased bowel extending to surrounding structures • (2) extraintestinal disease involving otherwise normal bowel • (3) trauma to normal bowel including inadvertent or missed enterotomies • (4) anastomotic disruption following surgery for a variety of conditions • Fistulas between the alimentary tract and skin may be classified as postoperative or spontaneous.

5. ETIOLOGIC CLASSIFICATION • Approximately three-quarters of fistulas occur following: • an operation,most commonly subsequent to procedures performed for malignancy, inflammatory bowel disease, or adhesions

6. ETIOLOGIC CLASSIFICATION • Patient factors that increase the likelihood of developing a postoperative fistula include: • Malnutrition • Infection • emergency operations with concomitant hypotension, anemia, hypothermia,and poor oxygen delivery

7. ETIOLOGIC CLASSIFICATION If possible, these conditions should be corrected prior to operation, but in emergency situations, optimization of resuscitation and performance of a technically meticulous procedure including adequate mobilization, good quality bowel with good blood supply, and no tension will provide the best chance of a good outcome.

8. ETIOLOGIC CLASSIFICATION • Postoperative enterocutaneous fistulas result from: • either disruption of the anastomosis • inadvertent (and often unrecognized) bowel injury during the dissection or abdominal closure • Attention to avoidance of tension or ischemia in the creation of anastomoses is paramount in minimizing postoperative enterocutaneous fistulas. • The remaining 25 percent of fistulas do not occur following a surgical procedure.

9. spontaneous fistulas • spontaneous fistulas often develop in: • patients with cancer • Following radiation therapy • Fistulas occurring in the setting of malignancy or Irradiation are unlikely to close without operative intervention. • Inflammatory conditions such as: • inflammatory bowel disease • diverticular disease • perforated ulcer disease • Ischemic bowel

10. spontaneous fistulas Of these, fistulas in patients with inflammatory bowel disease are most common; these fistulas often close following a prolonged period of parenteral nutrition, only to reopen when enteral nutrition resumes. An understanding of the etiology of an enterocutaneous fistula may provide information about the ultimate need for surgical intervention.

11. ANATOMIC CLASSIFICATION • Fistulas may communicate with • the skin (external fistulas) • or other intraperitoneal • or intrathoracic organs (internal fistulas)

12. ANATOMIC CLASSIFICATION Internal fistulas that bypass only short segments of bowel may not be symptomatic; however,internal fistulas of bowel that bypass significant length of bowel or that communicate with either the bladder or vagina typically cause symptoms and become clinically evident. However,internal fistulas of bowel that bypass significant length of bowel or that communicate with either the bladder or vagina typically cause symptoms and become clinically evident. The identification and management of internal fistulas is beyond the scope of this

13. ANATOMIC CLASSIFICATION • internal fistulas should be resected if : • they are symptomatic • cause physiologic or metabolic complications

14. Small bowel fistulas • .The majority of gastrointestinal cutaneous fistulas arise from the small intestine. • Seventy to ninety percent of enterocutaneous fistulas occur in the postoperative period. • postoperative small bowel fistulas result from either disruption of anastomoses or injury to the bowel during dissection or closure of the abdomen. • Operations for cancer • in flammatory bowel disease, and adhesiolysis are the most common procedures antecedent to small bowel fistula formation.

15. Small bowel fistulas • During the course of a procedure, resection with end-to-end anastomosis is recommended for small bowel defects and injuries, especially when simple closure would be expected to reduce the luminal diameter. • All sersosal injuries should be repaired with intermpted 3-0 silk sutures. • Spontaneous small bowel fistulas arise from inflammatory bowel disease, cancer, peptic ulcer disease, or pancreatitis. • Crohn's disease is the most common cause of spontaneous small bowel fistula. • The transmural inflammation underlying Crohn's disease may lead to adhesion of the small bowel to the abdominal wall or other abdominal structures.

16. Small bowel fistulas • Microperforation may then cause absces formation and erosion into adjacent structures or the skin. • Roughly half of Crohn's fistulas are internal and half are external. • crohn's fistulas tpyically follow one of two courses: • The first type represents fistulas that present in the early postop_ erative period following resection of a segment of diseased bowel. • These fistulas arise in otherwise healthy bowel and follow a course similar to non-Crohn's fistulas with a significant likelihood of sponta_ • neous closure. • The other group of Crohn's fistulas arises in diseased bowel and has a low rate of spontaneous closure.

17. Small bowel fistulas Additionally, should spontaneous closure occur, these fistulas often reopen upon resumption of enteral intake. Early operative closure of these fistulas should be considered.

18. Colonic fistulas Spontaneous fistulas of the colon result from diverticulitis, malignancy, inflammatory bowel disease, appendicitis, and pancreatitis, while treatment of these conditions accounts for the majority of postoperative colocutaneous fistulas. Anastomotic breakdown or extension from inadequately resected disease bowel account for the majoriry of the postoperative fistulas. Additionally,withgastrocutaneous fistulas, an increased incidence of colocutaneous fistulas has been reported following percutaneous gastrostomy placement.

19. Colonic fistulas Appendiceal fistulas may result from drainage of an appendiceal abscess or appendectomy in a patient with Crohn's disease. the fistula often originates from the terminal ileum, not the cecum. The inflamed ileum adheres to the abdominal wall closure and sub_ sequently results in fistula formation. Erosion of a percutaneous drain for spontaneous right lower quadrant abscess is also an increasing cause of gastrointestinal cutaneous fistula in Crohn's disease. Radiation therapy contributes to both spontaneous and postoperative colocutaneous fistulas.

20. Colonic fistulas Techniques to provide additional protection and blood supply to anastomoses performed under these conditions include coverage of anastomoses with omentum, filling of dead space with muscle flaps, or sigmoid exclusion. proximal diverting colostomy or ileostomy may allow sufficient anastomotic healing prior to sutureline challenge with luminal contents. Operation or reoperation in an irradiated field is subject to recurrence of colocutaneous fistulas, and these fistulas are unlikely to undergo spontaneous closure.

21. Fistula tract characteristic addition to describing the organs involved in fistulas, anatomic characteristics of fistula tracts may also be helpful in determining prognosis (Table 7-2). Due to anatomic considerations and the nature of effluent from different sites in the enteric tract, certain locations are more likely to undergo spontaneous closure. These favorable types include oropharyngeal, esophageal, duodenal stump, and jejunal fistulas. Unfavorable sites include the stomach, lateral duodenum, ligament of Treitz,and ileum.

22. Fistula tract characteristic

23. Fistula tract characteristic Anatomic factors suggesting low likelihood of spontaneous closure include fistulas associated with large abscesses, intestinal wall defects of greater than 1 cm, intestinal discontinuity, distal obstruction, diseased adjacent bowel, and fistulous tracts of less than 2 cm (Fig 7-5). In contrast, fistulas with intestinal wall defects less than 1 cm and longer tracts are more likely to undergo spontaneous closure.

24. Fistula tract characteristic

26. Physiological classification • Enterocutaneous fistulas cause the loss of fluid, minerals,trace elements, and protein, as well as allow the release of irritating and caustic substances onto the skin and subcutaneous tissues. • Accurate measurement of both the amount and nature of enteroCutan_ eous effluent allows for accurate replacement and an understanding of the physiologic and metabolic challenges to the patient (Table 7-3). • Fistulas may be divided into high-output (>500 mL per day), moderate-output (200-500 mL/day), and low-output (<200 mL/day) groups.

27. Physiological classification

28. Physiological classification Classification of enterocutaneous fistulas by the amount of daily output provides information regarding mortality, and in recent series may predict spontaneous closure. the classic series of Edmunds and associates, patients with high-output fistulas had a mortality rate of 54%, compared to a l6% mortality rate in the low-output group. More recently,Lervy and colleagues reported a 50% mortality rate in patients with high-output fistulas, while those with low-output fistulas had a 26% mortality.

29. Physiological classification • In the largest series reported to date, Soeters and coworkers reported no association between fistula output and rate of spontaneous closure, while multivatiate analysis by Campos and associates suggested that patients with low-output fistulas were three times more likely to achieve closure without operative intervention. • The reason for these different rates of closure is that high-output fistulas are likely to be of small-bowel origin,while low-output fistulas are likely to be of colonicorigin. • Moderate-volume fistulas tend to be of either colonic or mixed small- and large-bowel origin (seeTable 7-2).

30. Prevention • Proper preoperative patient preparation and meticulous surgical technique will lessen the risk of postoperative fistula formation. • In the elective setting, operation may be delayed to allow for normali_ zaion of nutritional parameters, thus optimizing wound healing and immune function. • Several nutritional characteristics have been suggested to increase the risk of anastomotic breakdown: 1. Weight loss of 10-15% of total body weight over 3-4 months 2. Serum albumin less than 3 mg/dL 3. Serum transferrin less than 220 mg/dL 4. Anergy to recall antigens 5. Inability to perform activities of daily living due to weakness or fatigue.

31. Prevention Mechanical and antibiotic bowel preparation reduce the amount of particulate fecal material as well as colonic bacterial counts. In practice, mechanical bowel preparation for elective colon operations combined with systemic antibiotics with activity against enteric organisms provides adequate prophylaxis.

32. Prevention In emergency operations, delays for optimization of nutritional status and bowel preparation are not possible. Instead, emphasis should be on adequate resuscitation and restoration of circulating volume, normalization of hemodynamics, provision of appropriate antibiotic therapy,and meticulous surgical technique Performance of anastomoses in a healthy, well-perfused bowel without tension provides the best chance for healing, especially when one can easily see the performance of the anastomosis clearly. Careful hemostasis to avoid postoperative hematoma formation will decrease the risk of abscess

33. Prevention • while inadvertent enterotomies and serosal injuries should be identified and repaired. If possible, an omental flap should be used to separate the anastomosis from the abdominal incision. Secure abdominal wall closure using healthy tissue and care to avoid injury to the underlying bowel are important to prevent postoperative fistula formation. • In the postoperative period, further resuscitation may be required to ensure hemodynamic stability and avoid inadequate tissue oxygenation. • It is essential to avoid periods of transient postoperative hypotension related to the anesthesia.

34. Diagnosis,Evaluation and Manegment • Regardless of the etiology or specific nature of the fistula,the ultimate goals in treating patients with enterocutaneous fistula are the re-establishment of bowel continuity,the ability to achieve oral nutrition, and the closure of the fistula. • Given the metabolic and septic physiology often present with entero_ cutaneous fistulas, recognition of the development of an enterocu_ taneous fistula should prompt aggressive resuscitation and stabilization of the patient.

35. Diagnosis,Evaluation and Manegment • Drainage of obvious septic sources must be undertaken and nutritional support commenced • Nutritional support should be delayed 24 hours for drainage, as hematogenous seeding of the catheter may result in catheter sepsis. • If an abscess is pointing, one should do a fistulogram through the abscessbefore open drainage, using an angiocath to see where the water-soluble dye tracks to.

36. Diagnosis,Evaluation and Manegment • This information in combination with the patient's response to nonoperative measures determines the length of time before operative intervention is performed. • If surgery is required, meticulous technique in combination with a well-prepared team approach will optimize the likelihood of a successful patient outcome. • Operative closure of the fistula does not end the surgical team's obligation to the patient, as continued nutritional support and physical and emotional rehabilitation are often required to return the patient to his or her pre-illness state. • As in any complicated illness, care of the patient with an enterocutan_ eous fistula can be divided into several phases (Table 7-4).

37. Diagnosis,Evaluation and Manegment

38. THANK FOR YOUR ATTENTION

39. Phase1:Recognition and Stabilization • Identification and resuscitation • the patient presenting with a postoperative enterocutaneous fistula may do well initially for the first few days after operation. • Within the first week, however, the patient may suffer delayed return of bowel function and fever. • Erythema of the wound develops and opening the wound reveals purulent drainage that is soon followed by enteric contents. • The diagnosis is now clear and management shifts from routine postoperative care to the management of a potentially critically ill patient.

40. Phase1:Recognition and Stabilization • The combined insults of the preoperative disease process,a bowel preparation, a week of minimal nutritional support, and a septic state often results in a profoundly volume-depleted patient. • The first stage in management of the fistula patient, therefore, is the restoration of volume using crystalloid and colloid products as appropriate to restore oxygen-carrying capacity and plasma oncotic pressure. • Several liters of crystalloid are usually required to replace fluid lost into the bowel and bowel wall.

41. Phase1:Recognition and Stabilization while maintenance of a specific target hematocrit is controversial, blood should be transfused to support oxygen-carrying capacity to a hematocrit of at least 30%. Similarly, albumin may aid in wound healing and intestinal functionoa and is involved in the transport of certain nutrients and medications Administration of albumin to a serum level of 3.0 mg/dL supports these functions.

42. Phase1:Recognition and Stabilization • Control of Sepsis • The leakage of enteric contents outside of the bowel lumen may lead to generalized peritonitis or abscess in addition to fistula formation. • As the leading cause of mortality in modern series of enterocutaneous fistula, aggressive management of sepsis is essential in these patients. • Frankly septic patients should be explored to drain abscesses. • ursing these procedures, consideration should be given to performing a fistulogram by injecting water-soluble contrast into the abscess under fluoroscopic guidance.

43. Phase1:Recognition and Stabilization Percutaneous drainage of collections in nonseptic patients should also be performed. Placement of central venous catheters for parenteral nutrition should be delayed for 24 hours following drainage of septic foci, as bacteremia following these procedures may seed catheters, leading to line sepsis. The use of antibiotics in patients with enterocutaneous fistulas should be reserved for specific indications. Most large series of patients with fistulas demonstrate that patients received seven to nine antibiotics during their treatment. in order to avoid selecting for resistant organisms, antibiotics should only be given for defined infections and for a set duration of therapy.

44. Phase1:Recognition and Stabilization • Control of fistula drinage and skin care • Concorent with drainage of sepsis, a plan to control fistula drainage and provide local skin care will prevent continued irritation of the surrounding skin and abdominal wall structures. • Very-low-output fistulas may appear to be adequately managed with dry dressings;however should the skin close over the fistula tract. • In this experience, a sump constructed from a soft latex catheter (i.e., Robinson nephrostomy tube) may be placed in the wound (Fig 7-6).

45. Phase1:Recognition and Stabilization

46. Phase1:Recognition and Stabilization This tube is soft at body temperature and will not erode into the bowel or abdominal wall structures. Accurate recording of fistula output is facilitated by this drainage system. More recendy, vacuum assisted closure (VAC) devices have been reported to both aid in the care of these complicated wounds and promote nonoperative closure( Fig 7-7).

47. Phase1:Recognition and Stabilization

48. Phase1:Recognition and Stabilization while there are no large series or randomized trials of the use of these devices in the management of enterocutaneous fistula, VAC dressings provide another option for wound care in these patients. The disadvantage of VAC dressings is the amount of time necessary to change these dressings, often 2-2.5 hours. However, these dressings need only bechanged every 5 or so days.

49. Phase1:Recognition and Stabilization • Reduction of fistula output • while fistula output does not correlate with the rate of spontaneous closure, reduction of fistula drainage may facilitate wound manage_ ment and decrease the time to closure. • In the absence of obstruction, prolonged nasogastric drainage is not indicated and may even contribute to morbidity in the form of patient discomfort, impaired pulmonary toilet,alar necrosis, sinusitis or otitis media, and late esophageal stricture. • Measures to decrease the volume of enteric secretions include admini_ stration of histamine antagonists or proton pump inhibitors.

50. Phase1:Recognition and Stabilization Reduction in acid secretion will also aid in the prevention of gastric and duodenal ulceration as well as decrease the stimulation of pancreatic secretion. Sucralfate, a mucosal protective agent, may also reduce gastric acidity while also providing a constipating action that may decrease fistula output as well As inhibitors of the secretion of many gastrointestinal hormones inclu_ ding gastrin, cholecystokinin, secretin,insulin, glucagons, and vasoactive peptide. it has been hoped that somatostatin and octreotide may reduce time to closure and promote nonoperative closure of enterocutaneous fistulas.