Spindle‐cell squamous carcinoma of the esophagus: a tumor with biphasic morphology. AJR Am J Roentgenol 1985; 145:541–545.
134 134 Ott DJ, Chen YM, Wu WC, et al. Radiographic and endoscopic sensitivity in detecting lower esophageal mucosal ring. AJR Am J Roentgenol 1986; 147:261–265.
135 135 Levine MS, Moolten DN, Herlinger H, et al. Esophageal intramural pseudodiverticulosis: a reevaluation. AJR Am J Roentgenol 1986; 147:1165–1170.
136 136 Ott DJ. Motility disorders of the esophagus. In: Gore RM, Levine MS, eds. Textbook of gastrointestinal radiology, 2nd ed. Philadelphia: WB Saunders; 2000, p. 316–328.
137 137 Woodfield CA, Levine MS, Rubesin SE, et al. Diagnosis of primary versus secondary achalasia: reassessment of clinical and radiographic criteria. AJR Am J Roentgenol 2000; 175:727–731.
138 138 Prabhakar A, Levine MS, Rubesin SE, et al. Relationship between diffuse esophageal spasm and lower esophageal sphincter dysfunction on barium studies and manometry in 14 patients. AJR Am J Roentgenol 2004; 183:409–413.
139 139 Levine MS. Varices. In: Gore RM, Levine MS, eds. Textbook of gastrointestinal radiology, 2nd ed. Philadelphia: WB Saunders; 2000, p. 452–463.
140 140 Levine MS. Miscellaneous abnormalities of the esophagus. In: Gore RM, Levine MS, eds. Textbook of gastrointestinal radiology, 2nd ed. Philadelphia: WB Saunders; 2000, p. 465–483.
141 141 Ginsberg GG. Management of ingested foreign bodies and bolus food impactions. Gastrointest Endosc 1995; 41:33–38.
142 142 Baron RL, Koehler RE, Gutierrez FR, et al. Clinical and radiographic manifestations of aortoesophageal fistulas. Radiology 1981; 141:599–605.
7 Special Endoscopic Imaging and Optical Techniques for Evaluating the Esophagus
John A. Dumot1, John J. Vargo2, and Arvind J. Trindade3
1 University Hospitals of Cleveland and Case Western Reserve University, Cleveland, OH, USA
2 Cleveland Clinic, Cleveland, OH, USA
3 Long Island Jewish Medical Center, New Hyde Park, NY; Zucker School of Medicine at Hofstra/Northwell
The role of visual identification of lesions and mucosal patterns is fundamental to the diagnosis of esophageal conditions. High‐definition white light endoscopy is the practice standard for all diagnostic and screening endoscopic exams. Special endoscopic imaging and optical techniques refer to technical developments beyond standard high‐definition. Some of these enhanced techniques are readily available at your fingertips with modern endoscopes. Other methods require topical or intravascular agents that interact with the lumen surface or enhance the vascular anatomy. Further enhancement has been found with laser techniques, which allow visualization of cellular structure. Specific mucosal and vascular patterns should prompt mucosal biopsies in the identification of dysplasia and neoplasia because early diagnosis is associated with high cure rates with endoscopic and surgical therapies.
Early neoplasia can occur in flat mucosa as well as appear elevated or depressed. Identification of neoplasia in flat mucosa requires a high index of suspicion. Dedicating time to learn the techniques of high‐quality examinations and applying it to your practice yields better outcomes. The rate of dysplasia detection seems to be directly related to the time observing the Barrett’s esophagus (BE) segment. Learning to slow down and pay attention can be one of the most satisfying opportunities in a time when we have an unprecedented number of tasks before and after endoscopic exams. In a post hoc analysis of 112 patients undergoing surveillance by 11 physicians, Gupta et al. found an inflection point in the rate of detecting suspicious lesions (54.2% vs. 13.3%; P = 0.04) and high‐grade dysplasia or adenocarcinoma (40.2% vs. 6.7%; P = 0.06) when an average of one minute of observation time per centimeter of BE length was reached [1]. Clearly, longer examination times are needed in longer segments of BE in order to correctly identify visible lesions, which will prompt dedicated biopsies or mucosal resection of those areas.
The standard of care is now high‐definition video images with a depth of field generally between 2 mm and 100 mm. Clear images of the mucosal surface pit pattern and microvascular architecture help identify areas of irregularity, which are more likely to represent areas of dysplasia. Some manufacturers have models with built‐in near field focus to give a zoom appearance. Further developments have introduced ultra‐high magnification up to 520×, allowing direct observation of cellular nuclei with staining and scattered light reflected back into the objective lens (EVIS Lucera Elite series, Olympus, Tokyo). The field of view is obviously narrow, so this technology has utility when there is a target lesion to study. The future holds promise for other developing technologies, including auto‐florescence imaging (AFI) that utilizes fluorescence intensity to differentiate areas of dysplasia and neoplasia in a wider field [2].
Friction‐fit soft caps are one of the most useful devices to stabilize the endoscope anywhere along the esophageal lumen in order to enhance the quality of the image. The cost and limitation of view are slight drawbacks when evaluating a patient suspected of having dysplastic changes when an irregularity is identified during the exam or prior biopsy results raises the clinical suspicion of dysplasia or early neoplasia. Systematic biopsy of BE remains the standard for surveillance protocols because a significant number of neoplastic areas are in nonvisible areas of flat mucosa [3]. Unlike BE, squamous cell dysplasia has no useful biopsy pattern because the entire esophagus could be at risk for dysplasia, and therefore, physicians must rely on chromoendoscopy to identify areas to direct biopsies.
Chromoendoscopy
Topical application of acetic acid (AA) or ethanoic acid 1–3% provides an enhanced view of Barrett’s mucosal surface. The method removes mucus and is followed by a transient whitening due to a transient protein acetylation when exposed to a pH of 2.5–3.0. BE epithelium without neoplasia tends to have longer whitening periods than areas of dysplasia and neoplasia, theoretically due to a reduced cytoplasmic content in worrisome areas. The technique of spraying AA requires practice and patience as detection of the loss of whitening appears as subtle areas of erythema within seconds.
Numerous reports and meta‐analysis have shown the utility in AA chromoendoscopy to identify BE and dysplastic areas. In a remarkable prospective trial of 132 patients conducted by a very experienced group in Portsmouth, UK, acetowhitening improved detection of neoplasia in BE with a cutoff of 142 seconds of application time and revealed neoplastic areas with a sensitivity of 97% and specificity of 84% [4]. In a retrospective report of their experience, Tholoor et al. AA found chromoendoscopy to be superior to standardized random biopsies in detecting dysplasia and neoplasia [5].
Iodine staining with Lugol solution (2.5% iodine) is a useful chromoendoscopy for squamous cell dysplasia and neoplasia. Normal squamous epithelium has a uniform uptake of the dark brown stain due to glycogen within squamous cells compared to dysplastic and neoplasia, where there is a deficiency of glycogen accounting for a void or lack of staining. In addition to a lack of uptake, a pink hue in the unstained mucosa within three minutes seems to be a more specific sign for high‐grade squamous intraepithelial neoplasia or more advanced neoplasia [6]. In a series of 79 patients with 121 lesions, the pink hue as the determinant produced a sensitivity of 91.9% and specificity of 94.0% for high‐grade intraepithelial squamous neoplasia and squamous cell carcinoma.
Indigo carmine and methylene blue have been used as contrast stains and do not have clinical utility in detecting more dysplasia or reducing the number of biopsies during surveillance of BE over electronic chromoendoscopy using narrow‐band imaging (NBI) [7, 8].
Electronic chromoendoscopy
Electronic or digital chromoendoscopy offers the provider real‐time alternative imaging at the push of a button. Blue‐light imaging came into practice around 2006 and was marketed as NBI [9]. The electronic exchange from high‐definition white