Radiation Enteritis and Proctitis Treatment & Management

Updated: Nov 06, 2019
  • Author: Neelu Pal, MD; Chief Editor: John Geibel, MD, MSc, DSc, AGAF  more...
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Treatment

Approach Considerations

Most patients initially respond well to conservative therapy; however, recurring symptoms and signs often eventually necessitate surgical intervention. Indications for surgical intervention include the following:

  • To prevent radiation-induced injury to the small bowel
  • To treat complications of radiation-induced injury to the small and large bowel, including perforation, obstruction (the most common presentation of chronic radiation enteritis), fistula, and bleeding (the most common presentation of chronic radiation proctitis)

Debate continues over the timing and extent of surgery for the complications of radiation-induced intestinal injury. Advocates of limited surgical procedures (including bypass procedures and diverting ostomy) suggest that these are safer, with a mortality of 2-10% and a morbidity of 20-30%. Other authors advocate wide resection of affected intestinal segments with anastomosis to the transverse colon. These authors report mortality and morbidity figures similar to those reported for bypass procedures.

The American Society of Colon and Rectal Surgeons (ASCRS) has formulated guidelines for the treatment of chronic radiation proctitis (see Guidelines). [21]

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Medical Therapy

Preventive measures

Measures designed to decrease or prevent the occurrence of radiation-induced enteropathy are an integral part of radiation therapy administration. Preventive measures include medical therapies to decrease the effects of radiation on the gastrointestinal (GI) tract. The commonly used methods of prevention include the following:

  • Basic bowel care (including maintenance of adequate hydration) and dietary modifications - Many patients develop transient lactose intolerance
  • Sulfasalazine, 500 mg orally twice daily - This has been shown to help reduce the incidence and severity of radiation-induced enteropathy in patients receiving external beam radiotherapy to the pelvis
  • Amifostine - This is a prodrug that is converted to its intracellular metabolite, WR-1065, which acts as a radioprotectant; intracellular oxidation of WR-1065 yields active metabolites that protect the cell by scavenging free radicals and stabilizing the DNA; amifostine administered intravenously (IV) in a dose of 340 mg/m 2 is proved to decrease the incidence of radiation proctitis in patients receiving standard-dose radiotherapy for rectal cancer; it has also been used as an intrarectal foam enema (ProctoFoam) with variable results [22]
  • Sucralfate, orally and as enemas - This has been proposed as a mucosal protective agent for prevention of radiation-induced enteropathy, with variable results
  • Glutamine - This is the preferred metabolic fuel for enterocytes; it may be an effective radioprotectant [23]

Prebiotics (eg, inulin and fructo-oligosaccharide) have been suggested as a possible means of helping to prevent acute radiation enteritis in patients with gynecologic cancer. [24]  Scartoni et al found that a zinc-based nutritional supplement to which prebiotics, tyndalized probiotics, and vitamins had been added was a safe and feasible means of protecting against radiation-induced diarrhea in patients undergoing pelvic radiotherapy. [25]

Medical control of symptoms

The following medical treatments aim to control the symptoms of radiation-induced enteritis and proctitis:

  • Adequate hydration
  • Antidiarrheals – Loperamide is a commonly used first agent; if diarrhea is not adequately controlled with the use of loperamide, octreotide at a dosage of 100 μg subcutaneously (SC) twice daily has been shown to be effective; cholestyramine also decreases the frequency of diarrhea
  • Antiemetic medication
  • Sucralfate enemas (used to decrease the bleeding associated with chronic radiation-induced proctitis)
  • Sulfasalazine, orally and as enemas (decreases the symptoms of tenesmus, abdominal cramping, and diarrhea associated with radiation enteritis and proctitis)
  • Hyperbaric oxygen therapy (considered in the treatment of intractable radiation proctitis, prior to surgical intervention)

Modification of radiotherapy

Modification in the delivery of radiotherapy may decrease radiation-induced bowel injury. Some of these techniques currently practiced include the following:

  • Multiple-field conformal therapy with prior three-dimensional (3D) planning
  • Pretreatment small-bowel contrast studies (to evaluate the position of the small bowel within the abdominopelvic cavity)
  • Methods to relocate the small bowel from the pelvic cavity into the abdominal cavity - Prone or Trendelenburg positioning; bladder distention; abdominal wall compression; open table-top device (belly board); temporary pneumoperitoneum

Nonsurgical bleeding control

Nonsurgical endoscopic interventions are commonly used to treat recurrent bleeding associated with chronic radiation proctitis.

Endoscopic argon plasma coagulation (APC) is the endoscopic technique of choice to control mucosal bleeding due to chronic radiation proctitis. [26, 27, 28] Compared with laser or heater probe therapy, APC has a limited depth of penetration, resulting in a lower risk of perforation. Multiple treatments are usually required, but bleeding is successfully controlled in 85-90% of patients.

The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been used to achieve hemostasis, but less successfully than APC. Some evidence suggests that radiofrequency ablation (RFA) is effective and safe for chronic radiation proctitis, but long-term data are limited. [29]  

Topical formalin therapy controls bleeding inexpensively and effectively. Two main techniques are used to apply formalin to the bleeding mucosa. In the first, formalin (50-mL aliquots of 4% solution for a total volume of 400 mL) may be instilled in the rectum via a proctoscope. The formalin remains in contact with the rectal mucosa for 30 seconds, followed with copious saline irrigation between applications. After each treatment and lavage, the rectal mucosa is examined for cessation of bleeding. This technique is used for diffuse bleeding from the mucosal surface.

In the alternative technique, formalin-soaked gauze is directly applied to an area of localized bleeding. Blind instillation of formalin via a rectal tube is not advised because of the risk of perforation. Anal-fissure formation is a common complication after formalin therapy. Hence, care must be taken with both techniques to protect the perianal skin.

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General Principles of Surgical Management

Choice of procedure

Surgical intervention may prevent or treat the complications of enteritis or proctitis. Preventive surgical procedures are performed in conjunction with the primary surgical procedure for cancer resection. [30] Patients are candidates for a primary surgical preventive procedure if they do not require abdominal or pelvic surgery for treatment of malignancy yet are at high risk to develop radiation-induced injury.

Surgical intervention is reserved for the most refractory cases and for complications such as obstruction, perforation, fistula, or hemorrhage. Operative treatment is individualized on the basis of the following:

  • Patient’s overall condition
  • Preoperative assessment of the lesion
  • Technical feasibility of performing the optimal surgical procedure
  • Intraoperative findings

Typically, patients with complicated small-bowel radiation injuries are best treated with resection if feasible, bypass if necessary, and diversion or exclusion of the affected segment as a last resort. Patients with complicated colorectal radiation injuries are best treated with resection and primary anastomosis, if possible. Proximal diversion should be performed if impaired healing of the anastomosis is a concern. Repair of fistulas may be performed via a transabdominal or perineal approach.

Preoperative evaluation and treatment

The preoperative evaluation for treatment of complications of radiation-induced intestinal injury reveals patients who are surgical candidates. Their overall condition is optimized prior to surgery, and surgical treatment is appropriately individualized in accordance with the severity and extent of the injury.

Radiation enteritis complications

Decompression of small bowel obstruction with placement of a nasogastric tube may be performed.

IV hydration and correction of electrolyte imbalance may be provided. Patients with small-bowel obstruction may be significantly dehydrated and have severe electrolyte abnormalities.

Unless an operation is done on an emergency basis, preoperative radiologic evaluation with small-bowel follow-through and barium enema should be performed. These studies may reveal synchronous lesions that are common in radiation enteritis and may influence the planned operative procedure.

Radiologic and endoscopic evaluation may exclude recurrent or primary malignancy. Radiation-induced strictures are longer, with gradual tapering to the point of stenosis with edematous, speckled-appearing mucosa. In contrast, malignant strictures have distinct separation from healthy intestine, and the mucosa and bowel wall have a heterogeneous appearance. These radiologic findings are not pathognomonic, and the tissue may have to be obtained endoscopically to differentiate malignant from radiation-induced strictures. Fistulas may also represent areas of recurrent or de-novo malignancy that must be differentiated from radiation-induced injury.

Comorbid conditions should be corrected or treated. Perioperative risks may be reduced through correction of severe anemia and optimization of nutritional status.

Radiation proctitis complications

Exclude recurrent local or disseminated cancer through endoscopic evaluation of tissue biopsy samples from the area of the fistula or stricture.

Evaluate the patient for suitability for major pelvic surgery. Patients who are debilitated may not be candidates for resectional procedures, which may lead to significant blood loss and the risk of anastomotic leak. These patients may be better served by a proximal diverting colostomy or a local fistula repair procedure.

Perform anal manometry to evaluate rectal compliance, anal function, and continence. The presence of a noncompliant rectum is an indication for a resectional procedure rather than a local fistula repair. Incontinence is an indication for a proximal colostomy rather than resection or repair.

Determine the surgical approach (dictated by the location of the fistula or stricture with respect to the levator ani muscle). High lesions are approached transabdominally, while low fistulas may be repaired via a perineal approach. Low-lying strictures may be addressed similarly with repeat anal dilations or transanal strictureplasty. Larger fistulas or those associated with strictures or significant proctitis require a transabdominal approach with resection.

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Surgery for Radiation Enteritis

Prevention

Surgical procedures for prevention of radiation enteritis (see Table 2 below) are based on the principles of reperitonealization and abdominopelvic partitioning.

Table 2. Surgical Procedures to Prevent Radiation Enteritis (Open Table in a new window)

Native Tissue

Prosthetic Materials

 

 

Reperitonealization procedures

Omentum-based procedures

Peritoneum and posterior rectus sheath

Omental transposition flap

Synthetic pelvic mold (spacer)

Uterine broad ligaments

Omentopexy - Omental apron or envelope

Saline-filled tissue expanders

Bladder

Omental hammock or sling

Absorbable mesh sling

With respect to abdominopelvic partitioning, surgical preventive procedures are used to exclude the mobile small bowel from the pelvic cavity, keeping it away from the area of maximal irradiation. Native tissue or prosthetic material may be used to create a partition between the abdominal and pelvic cavities or to enclose and contain the small bowel within the abdomen.

In reperitonealization procedures, native tissue (eg, peritoneum, bladder, uterine broad ligaments) may be used to create a separation between the abdominal and pelvic cavities. In omental-based procedures, an omental flap based on the left gastroepiploic pedicle is used to create the partition and to contain the small bowel within the abdominal cavity.

The absorbable mesh sling procedure is performed most often (of the operations that use prosthetic materials to exclude the small bowel from the pelvic cavity). Procedures performed less often use pelvic space–occupying devices to displace the small-bowel loops.

Technical considerations

Postoperative adhesions result in fixation of the small bowel, especially within the postoperative pelvis. The limited mobility of this bowel makes it more susceptible to radiation injury. Multiple surgical techniques to exclude the small bowel from the pelvis have been described in the literature. Typically, these procedures are performed with the primary surgical procedure for the malignancy. Occasionally, patients who do not require surgery to treat the primary malignancy still require a small bowel exclusion procedure, because they are at high risk of developing radiation-induced intestinal injury.

Small-bowel exclusion from the pelvis is best achieved using the omentum. Various techniques have been reported in the literature, three of which are commonly performed (see below).

In 1984, Russ et al described the omental transposition flap procedure. An omental pedicle flap based on the left gastroepiploic vessels is placed along the left paracolic gutter and sutured into place. The remainder of the omental bulk is packed into the pelvic cavity, effectively excluding the small bowel from occupying this space and providing protection from radiation injury (see the image below).

Omental transposition flap based on left gastroepi Omental transposition flap based on left gastroepiploic vascular bundle is sutured in place along the left paracolic gutter, and the omental bulk is packed into the pelvic cavity.

In 1985, DeLuca and Ragins described the omental envelope technique. [9] The omentum is draped over the small bowel as an apron. The lower edge of the omentum is sutured to the posterior abdominal wall at the level of the sacral promontory. The lateral borders are sutured to the ascending and descending colon (see the image below). This procedure is also known as abdominopelvic omentopexy .

Omental envelope is created by draping the omentum Omental envelope is created by draping the omentum over the small bowel and suturing the lateral edges to the peritoneum in the paracolic gutters. The lower edge is sutured to the posterior abdominal wall at the level of the sacral promontory.

In 1995, Choi and Lee described the omental pedicle hammock technique. [11] An omental pedicle based on the left gastroepiploic vessels is created and sutured circumferentially to the parietal peritoneum at the level of the sacral promontory and umbilicus. This creates a sling, or hammock, which contains the bowel and prevents it from entering the pelvis (see the image below).

An omental pedicle based on the left gastroepiploi An omental pedicle based on the left gastroepiploic vessels is sutured circumferentially to the parietal peritoneum at the level of the sacral promontory and umbilicus. This creates a sling, or hammock, which contains the bowel and prevents it from entering the pelvis.

Reperitonealization procedures use native tissue to isolate the pelvis from the abdominal cavity. The tissue is seldom adequate or strong enough to achieve adequate exclusion; thus, these are not commonly performed procedures.

In 1979, Freund et al described a technique of suturing the anterolateral peritoneum to the bladder to the posterior retroperitoneal tissues. [8] In women, the uterus and broad ligaments may be used in addition to the posterior tissue. Chen et al described the approximation of the peritoneum and the posterior rectus sheath to create a peritoneal reconstruction after resection of rectal cancer.

Many patients lack adequate peritoneum and omentum, often because of previous surgical procedures or the presence of extensive omental adhesions that make the tissue impossible to use. Alternative abdominopelvic partitioning procedures using prosthetic materials have been described. Currently, the prosthetic mesh sling procedure is performed most often.

In 1984, Devereux et al first described the absorbable mesh sling technique. [14] A polyglycolic acid or polyglactin mesh sling is sutured in place at the level of the sacral promontory and circumferentially attached to the retroperitoneum and lateral abdominal wall. Anteriorly, the mesh is attached at the level of the umbilicus. The small bowel loops are effectively encased within the mesh sling and separated from the pelvic cavity (see the image below). Care is taken to avoid injury to ureters and iliac vessels.

An absorbable mesh sling is created by suturing a An absorbable mesh sling is created by suturing a Vicryl or Dexon mesh to the sacral promontory, lateral abdominal wall, and anterior abdominal wall at the level of the umbilicus. Within this mesh sling, the small bowel loops are contained and held out of the pelvic cavity.

In 1979, Lavery et al reported the use of gauze packs encased in a latex dam to protect the abdominal viscera during high-dose radiotherapy for osteogenic sarcoma of the iliac bone. [12] Placement and removal of the pack required additional surgical procedures.

In 1983, Sugarbaker described the use of a silicone breast implant covered with a mesh baffle to fill the pelvis and to exclude the small bowel. [13] Likewise, Durig et al described the use of a solid synthetic pelvic spacer. More recently, Hoffman et al published their experience using saline-filled tissue expanders to occupy the pelvic cavity (see the image below).

Pelvic-space–occupying device. Pelvic-space–occupying device.

Treatment of complications

Surgical procedures to treat radiation enteritis complications (see Table 3 below) are selected on the basis of the extent of the involved bowel, as well as the technical feasibility of completing the procedure.

Table 3. Surgical Procedures to Treat Complications of Radiation Enteritis (Open Table in a new window)

Obstruction

Fistula

Perforation

Hemorrhage

Resection and anastomosis

Resection and anastomosis

Resection and anastomosis

Resection and anastomosis

Bypass of multiple/long strictures

Bypass of fistula area

 

 

Strictureplasty

Diversion with proximal ostomy

 

 

Diversion with proximal ostomy

 

Obstruction is the most common chronic complication affecting the irradiated small bowel. In patients with chronic radiation enteritis who require surgical intervention, 75-80% require treatment of an obstruction. Long or multiple stricture segments may be more appropriately treated with bypass.

Strictureplasty has been reported to successfully treat the obstruction. Strictureplasty involves performing a repair of enterotomies created over irradiated tissue and is associated with a higher risk of leak. Dissecting densely adherent bowel loops free within the pelvis may be impossible without significant risk of creating multiple enterotomies. Bypass of the affected bowel is preferable in these instances as well. Extremely debilitated patients are candidates for a proximal decompressing ostomy.

Fistulas account for 5-10% of irradiated bowel complications that necessitate surgery. Adjacent pelvic structures (ie, bladder, rectum, vagina) are areas in which fistulas often form with small bowel. Surgery entails resection of the involved small bowel up to healthy margins. Primary anastomosis of the divided ends of bowel is performed. The defect in the involved bladder, vagina, or rectum is closed primarily. Diversion of the enteric contents via a proximal ostomy is an option in the presence of a hostile abdomen or in patients who are severely debilitated.

Perforation is a rare complication of delayed effects of radiation and is often associated with obstruction. The treatment of perforation involves resection of the area of perforation with exteriorization of the divided ends of the bowel (if intraperitoneal contamination is extensive). Performing a primary anastomosis may be possible if the area of contamination is localized.

Hemorrhage rarely requires surgical intervention. An area of uncontrolled bleeding that can be localized within the small bowel but cannot be treated conservatively may require surgical resection of the involved bowel segment.

Technical considerations

Certain technical principles are crucial to the success of procedures performed to treat the complications of radiation-induced intestinal injury.

Lysis of adhesions should be limited because of the risk of inadvertent enterotomies and denudation of intestinal serosa. This increases the risk of peritonitis, sepsis, and fistula formation. Intestinal fistulas often form in patients who have undergone laparotomy to treat intestinal obstruction, which developed as a consequence of radiation injury. Enterotomies, serosal injuries, and nonhealing anastomoses in irradiated tissue results in the formation of fistulas.

Intestinal obstruction from dense adhesions of fixed bowel loops within the pelvis is best treated with bypass of the adherent strictured segments. In these patients, excessive attempts to lyse adhesions leads to a high complication rate, including short-bowel syndrome.

Perforation should be treated with resection of the involved segment, because bypass inevitably leads to the complications of fistula, peritonitis, or sepsis.

If resection is performed, at least one end of the anastomosis should include intestine that is located outside the irradiated field. Most often, this is the transverse colon or splenic flexure. Almost 50% of anastomoses that are performed in diseased bowel result in a breakdown because of the poor healing of irradiated tissue.

If the viability of an anastomosis is questionable, preferably, a stoma should be constructed.

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Surgery for Radiation Proctitis

Treatment of complications

The rectum, with its fixed position and proximity to the area undergoing treatment, is the most common site of injury following radiation to the pelvis. As such, long-term complications include hemorrhagic proctitis, rectovaginal fistulas, and rectal strictures (see Table 4 below).

Table 4. Surgical Treatment of Radiation Proctitis Complications (Open Table in a new window)

Hemorrhagic Proctitis

 

 

Rectovaginal Fistulas and Strictures

Transabdominal procedures

Perineal procedures

Proctectomy with coloanal anastomosis

Proctectomy with coloanal anastomosis

Transanal flap

Proctectomy with end colostomy

Proctectomy with end colostomy

Transvaginal flap

 

Colonic J-pouch-anal anastomosis

 

 

Ileocecal reservoir

 

 

Sigmoid colon onlay patch (Bricker-Johnston)

 

Most often, hemorrhagic proctitis is adequately treated with endoscopic APC or Nd:YAG laser treatment, heater probe coagulation, or application of formalin. [31] Patients with recalcitrant bleeding from the rectal mucosa may undergo proctectomy. This is a morbid procedure in the irradiated pelvis and is associated with significant blood loss. Primary anastomosis should be performed, if possible. If technically difficult, an end colostomy may have to be created. Creation of a proximal ostomy without resection has been reported in the literature; however, this procedure rarely controls the bleeding, since the diseased rectum remains in place.

Rectovaginal fistulas and rectal strictures are a common problem with irradiation. The treatment approach is transabdominal for high fistulas and perineal for low fistulas. The optimal surgical procedure is resection of the fistula and the affected bowel segment, followed with primary colorectal anastomosis. The vaginal defect is repaired or allowed to heal through secondary intention. Patients who are debilitated may benefit from a proximal diverting colostomy. Strictures are treated with resection and primary anastomosis, if possible. Proximal colostomy is an option for severely debilitated patients or in patients who are not good surgical candidates.

Technical considerations

In low-risk patients, rectal strictures and fistulas are best treated with proctectomy with reconstruction. The sigmoid and descending colon is mobilized, the rectum is resected down to the pelvic floor, and dissection within the rectovaginal septum is undertaken to separate the vagina from the rectum. The left colon and splenic flexure are adequately mobilized to obtain sufficient bowel length. The left colic artery and the inferior mesenteric vein at the inferior border of the pancreas are ligated to allow for the mobilization. Preserving the blood supply to the left colon is important. The distal transverse colon should be used as the proximal limb if the blood supply is questionable.

To reconstruct, the descending colon is anastomosed to the rectal remnant just proximal to the dentate line. The anastomosis is performed in an end-to-side manner using a stapling device. A colonic J pouch may be created to allow for improved fecal reservoir capacity. Stapling devices are used to create the colonic reservoir from 5- to 6-cm segments of the colon. The pouch is then either handsewn or stapled to the anus.

If a concomitant high vaginal fistula was resected, the vaginal vault is repaired in layers and omentum is interposed between the areas of resected tissue and anastomosis.

A proximal diverting colostomy may be created if healing of the anastomosis is a concern. The stoma is closed in approximately 3 months, once contrast imaging studies have demonstrated satisfactory healing of the anastomosis or J-pouch reservoir.

Patients who are not candidates for extensive resection procedures benefit from undergoing a proximal diverting colostomy.

Rectovaginal fistulas and strictures located in the distal rectum or anal canal are treated via perineal approaches.

The transanal technique is performed with the patient in jackknife prone position. A trapezoid flap of mucosa, submucosa, and circular muscle is mobilized for several centimeters above the fistula. To ensure adequate blood supply, the width of the base of the flap is twice the width of the apex. The fistula tract is excised and the edges are debrided. The flap is advanced to cover the defect and sutured in place, approximating the muscularis and the mucosa in two layers using long-lasting absorbable suture material. The vaginal side of the fistula is left open to permit drainage.

Transvaginal repair is performed in the dorsal lithotomy position. The vaginal mucosa is incised around the fistula and mobilized circumferentially. The fistula tract is excised and the tissue is debrided. A purse-string suture is placed around the fistula opening to invert the opening toward the rectum, and the vaginal mucosa is closed.

A transperineal approach follows the same principles of excision of the fistula tract, closure of the defect in layers without tension, and possible incorporation of well-vascularized tissue into the repair. A portion of the bulbocavernosus muscle or an island of vulvar skin and adipose tissue (Lehoczky island flap) may be used to close the defect created by the resected area of fistula tract.

The Bricker-Johnston onlay sigmoid patch procedure is rarely used to treat rectovaginal fistula. The fistula tract and surrounding rectal wall is resected. The mobilized sigmoid colon is anastomosed to this area of rectal wall.

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Complications

Factors that contribute to postoperative complications include the following:

  • Poor nutritional status
  • More than one laparotomy prior to radiation
  • Short interval (< 12 months) between radiation and surgical intervention

Surgery on irradiated tissue may lead to the following severe complications:

  • Significant blood loss
  • Inadvertent enterotomies
  • Fistula formation
  • Extensive bowel resection resulting in short-bowel syndrome
  • Creation of blind loops because of excessively long bypassed segments
  • Nonhealing of anastomoses performed on irradiated tissue
  • Anastomotic leakage with peritonitis and sepsis
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