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370

R. Garnkle and M. Boutros

Fig. 47.3 Mesosigmoidoplasty as a non-resective therapy for sigmoid volvulus. (a) Note the pathogenic long mesosigmoid and the narrow attachment at the base. (b) Note how the longitudinal incision is closed transversely, resulting in a shorter sigmoid loop and broader base.

colon, fecal contamination, hemodynamic instability or severe malnutrition/comorbidities. This allows for a relatively short operative time and diminishes the risk of anastomotic leak. If viable colon is encountered at urgent laparotomy in a clinically well patient, primary anastomosis with or without proximal diversion may be safe. The role of laparoscopy in the urgent setting is not well dened, and more evidence is needed before endorsing this technique as a standard approach.

For a cecal volvulus, the operation of choice will largely depend on bowel viability at the time of operation. In 20–30% of cases, the cecum is found to be gangrenous or nonviable, mandating a resection. A right hemicolectomy is typically necessary due to the extent of diseased colon, but ileocecectomy may be considered. The decision to perform a primary anastomosis or to mature an ileostomy with or without a mucus stula will depend largely on intraoperative ndings. Small observational studies have reported

(Reused with permission from Gordon PH, Nivatvongs S, editors. Principles and practice of surgery for the colon, rectum, and anus. third ed. NewYork: Informa Healthcare; 2007 (permission from editors))

primary anastomosis as a safe option in the emergency setting. However, in the setting of gross perforation and fecal contamination with generalized peritonitis, an ostomy should be strongly considered.

The best surgical intervention when facing a viable cecum is less obvious, largely due to a paucity of literature and high quality evidence. The options include simple detorsion, segmental resection, cecopexy, and cecostomy, and each choice must be considered in terms of its ability to prevent recurrence and its risk for postoperative morbidity and mortality. Simple detorsion is associated with the highest rate of recurrence, reaching 20% in some studies, as it does nothing to address the pathologically mobile colon. Coupled with a high rate of mortality, this technique is not recommended. Segmental resection essentially eliminates the chance of recurrence, but is associated with a postoperative morbidity rate of greater than 30%, mostly due to organ- space and supercial surgical site infections. The data on mortality

47 Colonic Conditions: Volvulus

371

is more difcult to interpret, but when cases of resection for viable bowel are distinguished from those performed for gangrenous bowel, mortality appears to be very low. Cecopexy, which involves suture xation of the cecum to the lateral abdominal wall, is another valid option (Fig.47.4). Recurrence rates are highly variable, as the success of this procedure depends on proper suture placement. Because the colon is not entered, infectious complications are lower than with resection, and mortality is acceptable. Operative cecostomy appears to be associated with both a higher rate of recurrence and

Fig. 47.4 Cecopexy (with cecostomy) with peritoneal ap as a non-resective therapy for cecal volvulus. The peritoneal ap is created at the level of the ileocecal valve and is extended to cover the ascending colon up to, but not

-ding, the hepatic exure. The ap is sutured to the taenia of the ascending colon using interrupted non- absorbable sutures. (Reused with permission from Gordon PH, Nivatvongs S, editors. Principles and practice of surgery for the colon, rectum, and anus. third ed. New York: Informa Healthcare; 2007 (permission from editors))

postoperative infections than cecopexy, and offers the added morbidity of a new ostomy. However, in patients who cannot tolerate a laparotomy or general anesthesia, tube cecostomy can be inserted by Interventional Radiology under local anesthesia. The use of laparoscopy for any of the above operative treatments is acceptable in the hands of an experienced minimally-invasive surgeon, but should not be entertained if gangrenous bowel is expected.

G. Successful endoscopic detorsion of sigmoid

volvulus converts an urgent operation to a semi-elective operation. Recurrence rates after endoscopic detorsion alone eclipse 50% within a few months of the index volvulus presentation, lending more support towards early operative intervention on the index admission, barring prohibitive medical comorbidities. The optimal timing for surgery is not well established; we aim for 5–7days from endoscopic detorsion, balancing the benet of continued colonic decompression and reduction in bowel wall edema with the risks of malnourishing the patient. In the interim, it is our preference that the rectal tube be left in place, and patients can be started on a high-protein high-caloric uid diet (e.g. Ensure, Boost). Solid diet is avoided as solid bowel movements could dislodge the rectal tube. Patients should also be marked for potential stoma prior to resection. In this setting, sigmoid colectomy can typically be performed by two possible operations.

The rst is a segmental resection performed via a limited left iliac fossa incision due to the redundant sigmoid colon which immediately bulges out (Fig.47.5). The length of sigmoid colon removed is variable, but should include the entire redundant segment that is exteriorized, leaving enough sigmoid on each side for a side-to-side stapled or end-to-end handsewn colocolic anastomosis. When dealing with proximal or distal bowel that is either still too edematous or chronically thickened from repeated insults, an anterior resection with stapled colorectal anastomosis should be considered. This can be performed laparoscopically or via a lower midline incision. The entire

372

R. Garnkle and M. Boutros

Fig. 47.5 Limited left iliac fossa incision for elective/ semi-elective sigmoid resection. (a) Note the location of the incision on the abdominal wall. (b) Note how the redundant sigmoid colon is easily delivered through the small incision, and the lines of resection are at the abdom-

redundant segment is resected down to the rectosigmoid junction and a colorectal anastomosis is performed. Proximal diversion with a loop ileostomy may be used. However, in the dependent patient, a Hartmann’s end colostomy may be the most suitable option. Regardless of the choice of anastomosis, recurrence rates after sigmoid colectomy are rare, and should be negligible when the entire redundant sigmoid colon is removed.

Non-resective and non-operative approaches as denitive management for sigmoid volvulus are inferior to sigmoid resection. While they were once performed to minimize postoperative morbidity, most case series have demonstrated equivalent complication rates to segmental colectomy with much higher recurrence rates, leading mostly to their abandonment. Simple operative detorsion is associated with approximately a 40–50%

inal wall. (Reused with permission from Gordon PH, Nivatvongs S, editors. Principles and practice of surgery for the colon, rectum, and anus. third ed. New York: Informa Healthcare; 2007 (permission from editors))

recurrence rate and a 30–35% morbidity rate, and should not typically be performed on its own. When combined with a colonic xation technique (sigmoidopexy; intra- or extra-peritoneal), recurrence rates are variable but hover around 20–30%. Another option is to combine detorsion with mesosigmoidoplasty, which addresses the long but narrow mesosigmoid, one of the most important pathogenic factors leading to sigmoid volvulus. This technique, which involves broadening and shortening of the mesosigmoid, appears to have greater success than sigmoidopexy, but is still associated with recurrence rates of up to 20% in some reports. In patients deemed unt for any operation, percutaneous endoscopic colostomy may be performed to x the sigmoid colon to the anterior abdominal wall. The evidence for this approach is sparse, but small reports support the technique as a viable non-operative option.

47 Colonic Conditions: Volvulus

373

Colonic Stricture

EstelleJ.Williams andErinO.Lange

Refer toAlgorithm inFig. 48.1

A. Colonic strictures result from a broad array

of benign and malignant colorectal conditions resulting in mechanical blockage of bowel contents. The underlying disease process may reect luminal, mural, or extramural pathology. In the acute setting, the obstructive nature of colonic strictures results in abdominal pain, distension, changes in bowel movement consistency or frequency, decreased/absent atus, nausea, and/or vomiting. These symptoms reect increased contractility in the colon as a physiologic response to relieve the acute obstruction. Although most strictures manifest with some degree of obstruction, the severity and tempo of the symptoms often depend on the underlying cause. For example, patients with a slow-growing malignancy may have a more indolent/subacute course with progressive difculty with bowel movements, bloating, etc. In the more chronic presentations, patients may also demonstrate weight loss, anemia, or malabsorption.

E. J. Williams Department ofSurgery, University ofWashington, Seattle, WA, USA

E. O. Lange (*) Colon and Rectal Surgery, SSM Health/St Mary’s Hospital, Madison, WI, USA e-mail: eolange@uw.edu

B. History and physical examination provide

important clues to identify the underlying cause of the stricture. Patients should be asked about duration of obstructive symptoms, diet tolerance and changes, appetite, weight loss, and bowel pattern, including frequency, consistency, and presence/absence of blood. Symptoms such as nausea, vomiting, fever, chills, and complete pain history including degree, location, and contributing factors should be elicited. Presence of fever or other acute symptoms should prompt consideration of perforation secondary to high grade obstruction, or infectious or inammatory etiologies: history of recent travel, hospital admission, or exposures may suggest tuberculosis, amebiasis, or other infectious colitides. Chronic worsening symptoms suggest malignancy, progressive diverticular disease, inammatory bowel disease, or radiation-induced stricture. Physical examination should include abdominal exam, with attention to distension, tympany, bowel sounds, and evidence of peritonitis. A rectal exam should be performed to exclude distal neoplasm or anal stricture.

C. Important laboratory tests include complete

blood count, chemistry, and coagulation panels. For patients with suspected neoplastic etiology, the tumor marker carcinoembryonic antigen (CEA) should be obtained. If inammatory bowel disease is suspected, inammatory markers such as estimated sedimentation

https://doi.org/10.1007/978-3-319-65942-8_48

375

376

E. J. Williams and E. O. Lange

Fig. 48.1 Algorithm for management of colonic stric-

∗

tures.

Medical therapy for diverticular disease includes antibiotics (IV or oral), bowel rest, and adequate uid resuscitation;

Medical therapy for IBD includes steroids,

rate (ESR) and c-reactive protein (CRP) can be obtained to evaluate the degree of inammatory response and to monitor treatment response against baseline. Stool cultures for Salmonella, Shigella, Campylobacter, Escherichia coli (E. coli) 0157:H7, Clostridium difcile (C. diff), and viruses such as cytomegalovirus (CMV) should be obtained if patients are immunocompromised, or have recent history of travel, hospital or institutional stay, or antibiotic use.

biologic agents, and other anti-inammatory medications;

Medical therapy for infectious diseases includes targeted antibiotics/antivirals, bowel rest, and adequate uid resuscitation

D. Imaging should be obtained as part of the ini-

tial assessment to differentiate proximal and distal locations. Abdominopelvic computed tomography (CT) with oral and intravenous contrast highlights the degree of bowel wall attenuation, bowel wall thickness, symmetry of thickness, and length of affected colon. In many situations, CT scans will provide insight into the underlying etiology of the stricture, particularly for non-infectious causes. CT scans have approximately

48 Colonic Stricture

377

93–98% sensitivity and 75–100% specicity in detecting diverticulitis. Pericolonic inammation with >10 cm of involvement and preservation of mucosal lining are the most important criteria in differentiating acute and chronic diverticulitis from neoplasm. However, in approximately 10% of cases, diverticular strictures cannot be reliably distinguished from stenosing neoplasm due to overlapping CT features. Colonoscopy is the preferred modality for direct evaluation of colonic pathology as it allows visualization of the stricture to identify intraluminal or extraluminal pathology. If an intraluminal lesion is seen, multiple biopsies should be obtained to assist with diagnosis. Contraindications to colonoscopy may include suspected perforation or medical instability. While complete evaluation of the colon is preferred, 5–15% of colonic strictures cannot be traversed with a colonoscope. If unable to pass the stenotic region, double contrast barium enema may provide additional information regarding lumen size and degree of obstruction (Fig. 48.2). Magnetic Resonance Enterography (MRE) has an important role in dening bowel anatomy, particularly in inammatory bowel disease (IBD), where diagnosis of disease-related

complications is reported with sensitivity 75–100% and specicity 91–100%.

E. Benign etiologies of colonic stricture

include diverticular disease, IBD, ischemia, infection, and sequelae of congenital pathology. In North American adults the most common cause of benign colonic stricture is diverticular disease, followed by Crohn’s disease, ischemic colitis, and radiation colitis. In the pediatric population, CMV and hemolytic uremic syndrome (HUS) caused by E. coli O-157 infection have resulted in numerous case reports of colon strictures. Congenital causes for stricture include neonatal necrotizing enterocolitis, or rarely colonic atresia or stenosis. Cystic brosis has been linked to the development of colonic strictures.

F. In the western hemisphere, diverticulosis

occurs in approximately 10–30% of the population >50 years old and 30–60% of the population >80 years old although most remain asymptomatic. In western countries, 95% of cases of acute diverticulitis are identied in the left colon and sigmoid, while in Asian countries up to 70% of disease is reported in the right colon. Diverticular disease- related colonic obstruction occurs in about 10% of patients. Hinchey classication for diverticulitis (Table 48.1) highlights the four stages. Stricture/obstruction can occur in any of the four stages but is most often seen in complicated diverticulitis stage II or above. Symptoms of diverticular stricture include persistent alteration in bowel function after resolution of the acute diverticulitis are, with abdominal pain, bloating, and intolerance of high ber foods often reported by patients. Relief of symptoms is often

Fig. 48.2 Barium enema, rectal stricture black arrow points to stricture

Table 48.1 Hinchey classication for diverticulitis

Stage I Stage II Stage III Stage IV Paracolic

abscess conned to mesentery of colon

See Touzios & Dozios 2009.

Distant abscess in pelvis or retroperitoneum

Purulent peritonitis

Feculent peritonitis

378

E. J. Williams and E. O. Lange

reported with soft/liquid diets and use of laxatives, and occasionally with use of antispasmodic medications. Colonoscopy is essential in conrming the diagnosis and delineating the degree of obstruction.

G. Strictures often occur in Crohn’s disease

(CD) secondary to prolonged inammation and brosis, but raise concern for underlying neoplasm. In contrast, all strictures in ulcerative colitis (UC) should be considered dysplastic or neoplastic. Approximately 60% of patients with Crohn’s disease suffer from colonic involvement, however, the North American and European incidence of colonic strictures in UC and CD is reported to be 5–17% and 5%, respectively. Strictures in IBD are classied as either inammatory or bro-stenotic lesions. The type of stenosis determines rst course of treatment: inammatory lesions are typically managed medically, while bro-stenotic lesions may undergo endoscopic dilation or proceed to surgical evaluation. Regardless of the underlying etiology, IBD strictures always carry concern for neoplasm, even if the biopsies are negative or inconclusive. Cancer is identied in surgically resected colorectal stricture for 0.8% of CD patients and 5% of UC patients, and results in 15% of all IBD deaths.

H. Ischemic strictures in the colon can be caused

by non-occlusive ischemic disease, arterial occlusive, and venous occlusive disease. Colonic stricture occurs in 10–15% of cases of ischemic colitis. Ischemia results from an acute self-limited compromise in intestinal blood ow. Non-occlusive ischemic disease can result from hypovolemic states due to congestive heart failure, transient hypotension in the perioperative period, or shock due to sepsis or hemorrhage which can result in hypo-perfusion. In arterial occlusive disease, mesenteric artery emboli, thrombus, or trauma may lead to interruption of blood ow and decreased colonic perfusion. Obstructed outow in venous occlusive disease leads to congestion. Strictures typically develop in patients >70years old with heart disease usually associated with diffuse dis-

ease in small segmental mesenteric vessels that predisposes to mal-perfusion. Watershed regions in the colon at the splenic exure, the region between the superior and inferior mesenteric artery distributions, and the rectosigmoid artery distribution are especially vulnerable due to limited collateral ow.

I. Infectious colonic strictures can occur in the

setting of ileocecal tuberculosis, lymphogranuloma venereum, colonic CMV, and a number of amebic and larial parasitic infections. Although rare, hemolytic uremic syndrome (HUS) caused by Escherichia coli O–157 can result in stricture formation during the postacute phase of HUS, with estimated 3% incidence. CMV colitis typically occurs in immunocompromised patients. However, CMV related colitis has been reported in up to 10–27% of immunocompetent patients requiring urgent colectomy, especially in those >55 years old. However, these patients typically have IBD, with only a few case reports available describing CMV- associated colonic stenosis affecting non- IBD immunocompetent patients.

J. Malignancy is a crucial diagnosis to con-

sider when evaluating colonic strictures. Colorectal cancer is the second leading cause of cancer death in the United States. Strictures as a result of an underlying neoplasm are the leading cause of large bowel obstruction in the U.S. population, ranging from 30–60% of all signicant obstructions, the majority of which occur in the sigmoid region. Metastatic lesions to the colon should be considered when multiple strictures are identied.

K. Iatrogenic causes of colonic stricture include

radiation treatment for cancer and anastomotic complications from a prior operation. Bowel segments exposed to external beam radiation or brachytherapy are susceptible to obliterative endarteritis due to radiation injury, leading to increased wall thickness and luminal narrowing. The rectum is the most common site of injury despite its relative resistance to radiation injury due to its xed position and therefore more consistent expo-

48 Colonic Stricture

379

sure. Technical elements of colorectal anastomosis may also predispose to stricture formation. A Cochrane review based on seven studies (1042 patients) shows increased frequency of stricture formation in stapled anastomosis at 8% versus 2% of hand-sewn anastomosis. Complications of anastomotic healing, including ischemia and anastomotic leak, can contribute to stricture development.

L. Treatment varies based on the underlying etiol-

ogy but options include medical management, endoscopic therapies, and surgical interventions. Asymptomatic benign colonic strictures, particularly ischemic or infectious, may resolve without specic therapy within 12–24 months. Therefore, symptoms should be used to guide the decision to intervene beyond observation. In the specic case of IBD-related inammatory strictures, medical therapies include steroids, 5- aminosalicylates, immunomodulators, and anti-TNF therapies. However, in the setting of brotic strictures, medical therapies are ineffective and more likely to require endoscopic or surgical treatment once the acute inammatory are is temporized. Endoscopic balloon dilations for IBD-associated strictures can be employed, and repeat dilations are often required. Selfexpanding colonic stents can be used for a variety of indications, including malignant and diverticular strictures. Stenting is often most successful with sigmoid or left sided lesions. Although there is a 90% technical success rate with stent placement, complications can include stent migration (40%) and perforation (20%). In malignant cases, perforation can result in higher loco-regional recurrence, altered pathology, and tumor cell dissemination. Given the frequency of complications, stenting is typically used as a bridge to surgery, allowing for temporary decompression and bowel preparation, with subsequent singlestage resection without diversion. Stenting only serves as denitive therapy for advanced malignancy or patients with medical problems prohibiting more aggressive intervention. In these settings, stents serve an important role in providing palliative relief of symptoms and

improving patient quality of life. For strictures arising from metastatic disease, often with long, multifocal diseased segments associated with external compression, stent failure rate has been reported as high as 60%. Stents have been successful in up to 80% of transverse colonic strictures due to gastric cancer compression.

M. Surgical intervention is indicated for known or

suspected malignancy, or for strictures refractory to other treatment methods. Colonic strictures should be treated with segmental resection, maintaining oncologic principles of appropriate margins, blood supply ligation, and lymph node harvest. Stricturoplasty is generally contraindicated in the treatment of colonic strictures, but may be considered in rare instances of short segment stricture. If the patient is not t for denitive surgical intervention, diversion via laparoscopic or open approach may be used to relieve obstruction and minimize the morbidity of potential perforation. Barriers to denitive surgical intervention, such as malnutrition, infection, and glycemic control, should be addressed preoperatively in order to optimize the patient for future denitive surgical management.