CHAPTER 7 Interventional endoscopy
7.1 Stricture dilation
Key Points
1 Clinical and endoscopic assessment
1.1 Esophageal strictures
Clinical Tips
1.2 Gastric, pyloric, and small bowel strictures
Clinical Tips
3 Endoscopic techniques
3.1 General principles
3.1.1 Dilation using bougies
3.1.2 Dilation using balloons
Clinical Tips
3.2 Esophageal strictures
Box 4 ASGE guidelines for the performance of esophageal dilation
3.3 Achalasia
3.4 Gastric/pyloric strictures
3.5 Small intestinal/colonic strictures
4 Complications
Borotto E, Gaudric M, Danel B, et al. Risk factors of oesophageal perforation during pneumatic dilatation for achalasia. Gut. 1996;39:9-12.
Hernandez LV, Jacobson JW, Harris MS. Comparison among the perforation rates of Maloney, balloon, and savary dilation of esophageal strictures. Gastrointest Endosc. 2000;51:460-462.
Kochhar R, Makharia GK. Usefulness of intralesional triamcinolone in treatment of benign esophageal strictures. Gastrointest Endosc. 2002;56:829-834.
Kuwada SK, Alexander GL. Long-term outcome of endoscopic dilation of nonmalignant pyloric stenosis. Gastrointest Endosc. 1995;41:15-17.
Lemberg B, Vargo JJ. Balloon dilation of colonic strictures. Am J Gastroenterol. 2007;102:2123-2125.
Pereira-Lima JC, Ramires RP, Zamin IJr, et al. Endoscopic dilation of benign esophageal strictures: report on 1043 procedures. Am J Gastroenterol. 1999;94:1497-1501.
Sgouros SN, Bergele C, Mantides A. Eosinophilic esophagitis in adults: what is the clinical significance? Endoscopy. 2006;38:515-520.
7.2 Emergency endoscopy in benign gastrointestinal obstruction
Key Points
Information about the emergency management of gastroduodenal or colonic obstruction due to stricture or malignancy can be found in Chapter 7.3.
1 Volvulus
1.1 Gastric volvulus
Gastric volvulus is a rare, potentially life-threatening entity that occurs when the stomach twists upon itself (Fig. 1). By definition, gastric volvulus is rotation of the entire or part of the stomach more than 180°. It is supra-diaphragmatic and associated with a paraesophageal or a mixed diaphragmatic hernia in two-thirds of the cases, and is subdiaphragmatic in the remaining one third. The volvulus is organoaxial in 60% of cases where the axis passes through the gastroesophageal and gastropyloric junctions, and mesenteroaxial in 40% of cases where the axis bisects the lesser and greater curvatures.
Warning!
Clinical Tips
The alpha-loop maneuver (Fig. 2)
1.2 Colonic volvulus
Colonic volvulus is the third most frequent cause of large bowel obstruction after neoplasms and diverticulitis. Whereas colonic neoplasms and diverticulitis usually result in an open-loop obstruction where the lumen is occluded at a single point along the bowel segment, colonic volvulus occurs when a colonic segment becomes twisted on its mesenteric axis and occludes both ends of the bowel segment resulting in a closed-loop obstruction (Fig. 4). The mesentery gets trapped and the blood supply to the bowel segment becomes strangulated, potentially leading to gut ischemia, necrosis and perforation. Delay in diagnosis and decompression compromises viability of the bowel and is a major cause of mortality.
The sigmoid colon (Fig. 4) and cecum (Fig. 5) are the most frequent sites of colonic volvulus, accounting for 75% and 22% of all cases, respectively. Patients with acute colonic volvulus present most commonly with acute abdominal distension and may have other non-specific symptoms of abdominal pain, nausea, vomiting, and constipation. The diagnosis of colonic volvulus can be made with plain abdominal films (supine and upright) or water-soluble contrast enemas in 85% of the cases.
Clinical Tips
Acute colonic volvulus should be managed on an emergent basis. Patients with colonic necrosis/perforation should be managed surgically. A more conservative approach with an initial attempt at endoscopic detorsion and decompression can be followed in more stable patients (Fig. 6). The benefits of such a strategy are:
Figure 6 Endoscopic view of a sigmoid volvulus. (A) Before reduction. (B) Following endoscopic reduction.
Clinical Tips
Endoscopic treatment of colonic volvulus
2 Acute colonic pseudo-obstruction
Acute colonic pseudo-obstruction, also known as Ogilvie’s syndrome, is a disorder characterized by massive colonic dilation in the absence of colon obstruction. This definition excludes toxic colitis, which occurs in the setting of severe colitis secondary to inflammatory bowel disease or infection. It occurs most often in the setting of surgery and severe medical illnesses, and thus is a disorder of institutionalized patients. Acute colonic pseudo-obstruction is believed to result from autonomic imbalance with suppressed large bowel parasympathetic tone. This results in decreased colonic motility, accumulation of gas and fluid in the colon, increased intraluminal pressure, colonic distension and rising wall tension. Wall tension is highest in the cecum where the colonic diameter is the largest. This may result in the impediment of cecal capillary circulation and lead to ischemia, gangrene, and subsequent perforation. Plain abdominal radiographs show diffuse dilatation of the colon. A cutoff in the colonic gas is often seen at the hepatic flexure, splenic flexure, or sigmoid region with minimal air distal to the cutoff (collapsed left colon). Unlike toxic colitis, preserved haustral markings, smooth inner colonic contour, and thin colonic wall are present. In contrast to mechanical obstruction, air fluid levels are absent and distension is gaseous (Figs 7, 8). Water-soluble contrast enema is usually needed to rule out a true mechanical obstruction.
Clinical Tips
Box 1 Treatment of acute colonic pseudo-obstruction: conservative measures
Warning!
Box 2 Facts about neostigmine
Box 3 Facts about colonoscopic decompression in patients with acute colonic pseudo-obstruction
Patients who fail medical and endoscopic treatment and those with signs of colonic perforation/necrosis should be treated surgically with cecostomy or colectomy. Figure 9 illustrates an algorithm suggested by the ASGE for treating patients with ACPO.
Eisen GM, Baron TH, Dominitz JA, et al. Acute colonic pseudo-obstruction. Gastrointest Endosc. 2002;56:789-792.
Godshall D, Mossallam U, Rosenbaum R. Gastric volvulus: case report and review of the literature. J Emerg Med. 1999;17:837-840.
Loftus CG, Harewood GC, Baron TH. Assessment of predictors of response to neostigmine for acute colonic pseudo-obstruction. Am J Gastroenterol. 2002;97:3118-3122.
Madiba TE, Thomson SR. The management of cecal volvulus. Dis Colon Rectum. 2002;45:264-267.
Ponec RJ, Saunders MD, Kimmey MB. Neostigmine for the treatment of acute colonic pseudo-obstruction. N Engl J Med. 1999;341:137-141.
Renzulli P, Maurer CA, Netzer P, Buchler MW. Preoperative colonoscopic derotation is beneficial in acute colonic volvulus. Dig Surg. 2002;19:223-229.
Tejler G, Jiborn H. Volvulus of the cecum. Report of 26 cases and review of the literature. Dis Colon Rectum. 1988;31:445-449.
Tsang TK, Walker R, Yu DJ. Endoscopic reduction of gastric volvulus: the alpha-loop maneuver. Gastrointest Endosc. 1995;42:244-248.
7.3 Esophageal, duodenal and colorectal stenting
Key Points