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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_627_Библиотеки_им_академика_М_И_Перельмана
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the anal canal to detect premalignant lesions.
In 1997, Jay et al. reported high-resolution anoscopy (HRA) using a
colposcope in conjunction with an anoscope to describe the appearance
of anal SILs and their relationship to histopathology.
In 2017, Oette and coworkers described anal chromoendoscopy (ACE)
using gastroenterological video endoscopes.
Inkster et al. described chromoendoscopy with narrow-band imaging
(NBI) and NBI with acetic acid (NBIA) using both en face and
retroflexed views to detect anal dysplasia.
Preprocedural Interview
A history is obtained and physical examination is performed. Risk factors
for anal HPV disease are identified.
Baseline anal cytology is typically obtained.
The perianal skin and anal canal are examined by inspection, palpation,
and 1× anoscopy. Perianal condyloma, as shown in Figure 18-2, is noted.
FIGURE 18-2 Perianal or anal margin condyloma acuminata (arrows) are located on
the hair-bearing skin.
Lesions of the mouth, nares, eyelids, penis, or gynecologic areas are
referred for appropriate follow-up.
Sterile Instruments/Equipment
Colposcope
Dilute acetic acid (3% solution)
Lugol iodine solution
Cotton-tip applicators
Forceps/needle driver/scissors
Biopsy forceps
Electrocautery
3-0 Vicryl or chromic suture
Colonoscope with NBI
Clear self-lighted plastic disposable anoscope
TECHNIQUE
Detection of Anal Dysplasia
Anal Colposcopy/High-Resolution Anoscopy
The patient undergoes a full cathartic bowel preparation with miralax prior
to the procedure.
The procedure is performed in the operating room under general
anesthesia.
The patient is placed in the lithotomy position utilizing yellow-fin stirrup.
The perianal skin and anal canal are examined through a colposcope to
identify lesions (Fig. 18-3).
FIGURE 18-3 Anal colposcopy (high-resolution anoscopy). The anoderm is inspected
through an anoscope with a colposcope.
Treatment of the anoderm with dilute acetic acid makes abnormal
epithelium appear white (“acetowhite”). This is performed using a cotton
tip applicator soaked in the acetic acid and applied to the anoderm.
Treatment with Lugol iodine solution stains the glycogen-containing
normal epithelium brown; abnormal epithelium, depleted of glycogen,
does not take up the stain. A saturated cotton tip applicator is soaked in
Lugol’s solution and it is applied directly to the area.
The appearance of anoderm stained with Lugol iodine is shown in Figure
18-4.
FIGURE 18-4 Treatment of the anoderm with Lugol iodine stains normal anoderm
brown (arrows).
Lesion detection is enhanced using a green filter.
Biopsy of abnormal-appearing epithelial lesions is done to establish their
histopathologic identity.
The appearance of anal low-and high-grade lesions, as seen through a
colposcope, is shown in Figures 18-5 and 18-6, respectively.
FIGURE 18-5 A. Diffuse low-grade anal lesion (white arrows) seen through a
colposcope. B. Histopathologic appearance of the lesion seen in A. The squamous
epithelium shows prominent koilocytes, characterized by enlarged, hyperchromatic, and
angulated nuclei (arrow) showing perinuclear halos. Binucleation is common (arrowhead).
The cells maintain an overall low nuclear-to-cytoplasmic ratio, and there is no significant
expansion of the basal layer (curved arrow). The overall findings are diagnostic of lowgrade squamous intraepithelial lesion.
FIGURE 18-6 A. Examination of the anoderm through a colposcope with a green filter
after treatment with acetic acid reveals a raised lesion (arrow). B. The squamous
epithelium of this lesion shows partial thickness atypia (arrows), characterized by
disorganized polygonal cells with eosinophilic cytoplasm, increased nuclear-to-cytoplasmic
ratio, nuclear hyperchromasia, numerous mitoses (curved arrow), and dyskeratotic
keratinocytes. The upper third of the squamous epithelium (arrowhead) shows maturation
with evenly spaced nuclei and a low nuclear-to-cytoplasmic ratio. This would previously
have been classified as AIN II; however, it is now classified as HSIL per the LAST
consensus.1 AIN, anal intraepithelial neoplasia; HSIL, high-grade squamous intraepithelial
lesion.
Anal Chromoendoscopy
Oette et al. used gastroenterological video endoscopes to perform HRA for
the diagnosis of intraepithelial dysplasia and anal carcinoma in HIVinfected patients.
Their technique, ACE, involves anoderm examination en face after surface
staining with acetic acid and Lugol solution.
ACE is performed with a mucosectomy cap on the tip of the endoscope.
The authors conclude that ACE is a valuable method to exclude anal
dysplasia if the procedure is performed by well-trained endoscopists.
CHROMOENDOSCOPY WITH RETROFLEXION AND
INSUFFLATION
High-definition chromoendoscopic detection of anal lesions using both en
face and retroflexed views (Fig. 18-7A and B) plus NBI is documented.
FIGURE 18-7 A. A lesion in the anal transitional zone (distal rectum) is examined with
retroflexion following insufflation. B. A lesion within the anal canal is examined en face
through a beveled clear plastic anoscope.
As noted by Tanaka et al., retroflexion and insufflation distend the rectum
and facilitate visualization of the anal columns and sinuses of the anal
transitional zone (ATZ) similar to an open umbrella (Fig. 18-8).
FIGURE 18-8 A. Retroflexed view of the ATZ, bordered proximally by the anorectal
line and distally by the dentate line, seen under NBI. The pecten lies distal to the dentate
line. B. En face view of the ATZ (between the columnar epithelium and the pecten) seen
with white light through a self-lighted beveled anoscope. A, anterior; ATZ, anal transitional
zone; L, left; NBI, narrow-band imaging; R, right; Scope, endoscope.
Inkster and coworkers visualized the anoderm by chromoendoscopy with
both en face and retroflexed views aided by NBI and NBIA to detect anal
SIL.
A clear self-lighted plastic disposable anoscope is used to facilitate
identification, biopsy, and removal of lesions in the anal canal.
Approach Advantages
Retroflexion with rectal air insufflation provides a view of the effaced
ATZ.
Examination through a beveled self-lighted clear plastic anoscope
provides en face views of the ATZ and pecten. The anoscope increases the
diameter of the anal canal, facilitating magnified endoscopic visualization
of the epithelium.
Chromoendoscopy with NBI and NBIA facilitates identification of anal
SIL.
Lesions can be biopsied and ablated endoscopically using standard
endoscopic equipment.
The location and appearance of the lesion are preserved as part of the
electronic record (ProVation/Epic, Provation Medical. Minneapolis, MN).
The appearance of any area can be compared with that seen in previous
examinations.
The techniques used are part of routine gastrointestinal practice.
Normal Anal Anatomic Landmarks
Retroflexion and en face views of both the distal rectum and the anal canal
show the anorectal line, the ATZ, the dentate line, and the pecten.
These anatomic structures in normal patients are shown in Figure 18-8.
Examples of Chromoendoscopy with Retroflexion and
Insufflation
The following abbreviations were used in the images that follow: A,
anterior; ARL, anorectal line; ATZ, anal transitional zone; L, left; P,
posterior; PEC, pecten; R, right; Scope, endoscope.
Figure 18-9 shows how the rectal anatomy can be determined by
identification of prominent anatomic landmarks and by the position of
water.
FIGURE 18-9 This examination was performed with the patient lying on their left side.
Liquid lies in the dependent position. The contour of the right and left levator ani is seen.
The levator sling is open anteriorly, allowing the pecten distal to the dentate line to be
seen. A, anterior; DL, dentate line; L, left; P, posterior; R, right; Scope, endoscope.
In Figure 18-10A, multiple lesions are seen tangentially with an en face
view of the anal canal seen at routine white light screening colonoscopy.
Retroflexion brings multiple lesions into view (Fig. 18-10B).
FIGURE 18-10 A. En face view of the anal with white light showing multiple ill-defined
lesions (white arrows). B. Retroflexed view of the rectum with insufflation and white light
illumination showing multiple discrete ATZ lesions (black arrows). Biopsy showed LSIL.
ATZ, anal transitional zone; LSIL, low-grade squamous intraepithelial lesion; Scope,
endoscope.
The patient depicted in Figure 18-11 underwent screening colonoscopy.
FIGURE 18-11 A. A lesion is seen on the left anterior ATZ with retroflexion and white
light illumination. B. The same lesion as in A seen with NBI shows punctation (black
arrow) and mosaicism (white arrow). C. Follow-up examination of the same site after
lesion ablation shows a scar (black arrow) without residual tumor. Pathology showed
HSIL. A, anterior; ARL, anorectal line; ATZ, anal transitional zone; HSIL, high-grade
squamous intraepithelial lesion; L, left; NBI, narrow-band imaging; R, right; Scope,
endoscope.
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