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110 D.G. Kim and W.D. Wong
Other causes of anatomic anal sphincter defects include
anorectal trauma or surgery and congenital anomalies. Blunt
or penetrating trauma to the perineum may involve the
sphincter mechanism. Management often includes fecal
diversion, and debridement of the associated perineal soft tissues. After the perineal wound has healed, EAUS may be
used to assess anal sphincter anatomy to determine if sphincter reconstruction is necessary before colostomy closure.
Patients undergoing anorectal surgery may experience transient minor incontinence in the early postoperative period,
which usually resolves spontaneously. Patients who have persistent symptoms of incontinence may warrant evaluation.
EAUS provides an objective means to evaluate the anal sphincter mechanism in patients with postoperative fecal incontinence
after anorectal surgery such as hemorrhoidectomy, fistulotomy,
lateral internal sphincterotomy, or sphincteroplasty.
The surgical correction of congenital anorectal anomalies
is based on reconstituting the anatomy of the anorectum. The
goal of posterior sagittal anorectoplasty (PSARP) is to place
FIGURE 7-14. This image depicts a complete anterior sphincter disruption in a female patient. The hypoechoic internal anal sphincter
can be seen completely disrupted in its anterior location (A arrows).
Similarly, the hyperechoic external anal sphincter is completely disrupted anteriorly (B arrows).
sphincter defect. An examining digit used to measure the
perineal body distance in the mid anal canal can accentuate an
anterior sphincter defect, helping to identify a sphincter injury
(Figure 7-15).
59
the bowel within the striated muscle complex of the levator
ani and external anal sphincter.
60
EAUS has been used to
accurately confirm the position of the neo-anus within the
anal sphincter complex comparing favorably with MRI.
EAUS in fact provided greater detail of the anal muscles than
MRI and had better correlation with direct perineal muscle
stimulation.
61
Adult patients who present with severe fecal
incontinence after previous surgical repair of a congenital
anorectal malformation can undergo successful PSARP.
Usually, the existing anus is anterior to the sphincteric muscle
complex.
62
An EAUS can be performed to help define the
relationship of the anus to the sphincteric mechanism.
The identification of localized sphincter defects is important in the evaluation of the incontinent patient, because these
defects may be amenable to surgical repair. EAUS can clearly
and objectively image the anal sphincter mechanism and has
replaced needle electromyography as the procedure of choice
for anal sphincter mapping. EAUS is better tolerated and less
painful than needle electromyography sphincter mapping.
Anorectal manometry and pudendal nerve terminal motor
latency testing are complementary but do not definitively
correlate with a surgically correctable defect.
46,52,54,63,64
EAUS remains the definitive test that can identify a surgically correctable defect in a symptomatic patient with fecal
incontinence.
61
62
FIGURE 7-15. This image demonstrates the measurement of the anterior perineal body in this patient with an anterior sphincter disruption. The curvilinear hyperechoic structure (A) is the examiner’s
finger in the vagina. This technique can often accentuate the defect
(B) seen in the internal anal sphincter and the external anal sphincter, and documents the decreased thickness of the anterior sphincter
and perineal body.
Evaluation of Perianal Sepsis and Fistula-in-Ano
Typically, the diagnosis of a perianal or perirectal abscess is
quite apparent on physical examination and only requires
proper identification and prompt drainage. Occasionally, an
abscess is strongly suspected on clinical grounds but is not
readily identified on physical examination. In these situations,
an EAUS may be useful in the evaluation of perianal or
perirectal abscesses. EAUS can be helpful to localize an
obscure abscess to plan the appropriate surgical intervention.
7. Endoluminal Ultrasound 111
Often, clinical examination of perianal or perirectal
abscesses is quite painful and examination under anesthesia is
required. Because the ultrasound equipment is portable, the
EAUS examination can be performed in the operating room
while the patient is anesthetized. Abscesses appear as hypoechoic areas often surrounded by a hyperechoic border. In
patients with perianal Crohn’s disease, EAUS may be useful
in distinguishing discrete abscesses that require surgical
drainage from inflammation that requires medical treatment.
The use of EAUS has also been evaluated in patients with
ileoanal pouch anastomosis and can be helpful in demonstrating pouch pathology including inflammation, abscesses, and
fistulas.
65
The natural history of a drained perianal/rectal abscess is
either complete resolution or fistula formation. The majority
of fistulas that occur are simple intersphincteric fistulas that
are easily identified and treated by simple unroofing.
However, occasionally fistula tracts develop that are extensive
and highly complex. These complex fistulas present a diagnostic challenge to even the most experienced colon and rectal surgeon. Use of EAUS can be helpful in identification of
fistulous communications in patients with complex and recurrent fistula-in-ano.
66–68
Fistula tracts are generally hypoechoic
defects that can be followed to identify direction and extent.
FIGURE 7-16. This image depicts a fistula-in-ano that has been
enhanced by the introduction of hydrogen peroxide. The hyperechoic features posteriorly represent the hydrogen peroxide within the
fistula tract (short arrows). There is an obvious hypoechoic defect in
the internal anal sphincter in the midline posteriorly (A), representing the internal fistula opening. The hypoechoic horseshoe tract can
be seen extending toward the patient’s left.
The anatomic details of the fistula tract can be delineated in
relation to the anal sphincter. The EAUS examination should
include the anal canal and distal rectum to search for the presence of high blind tracts. Hydrogen peroxide has been used to
enhance the imaging of complex fistula.
69–72
Hydrogen peroxide causes a release of oxygen, accentuating the fistula and
appears as a brightly hyperechoic image on the ultrasound
image. The technique increases the identification of the internal opening to greater than 90%.
69,72
An example of a fistulain-ano with hydrogen peroxide enhancement is demonstrated
in Figure 7-16. When evaluating an anal fistula with ERUS, it
is important to use both the balloon-covered transducer to
evaluate the perirectal region to assess for any supralevator
extension as well as the plastic cap for evaluation of the anus
and surrounding anatomy.
evaluation and histologic confirmation by tissue biopsy. Anal
canal malignancies evaluated by EAUS include leiomyosarcomas, malignant melanomas, anal canal adenocarcinomas,
and squamous cell carcinomas. Squamous cell or epidermoid
carcinoma of the anal canal are the most common anal canal
malignancy. EAUS can be used in the initial evaluation to
stage the lesion as well as in follow-up for patients with squa-
73–76
mous cell carcinoma of the anal canal.
Because squamous
cell carcinomas of the anus are primarily treated nonoperatively with combined chemoradiation therapy, it is desirable
to have an accurate method of staging to assess response to
multimodality therapy. EAUS accurately stages the initial
tumor and can be used in follow-up to detect residual tumors
as well as early recurrences after treatment. Surgical treatment in the form of abdominoperineal resection is reserved as
Anal Canal Neoplasms
Endoanal ultrasonography images the normal anal canal and
associated pathologies quite well. EAUS can have an important role in the evaluation of benign and malignant anal canal
neoplasms. The normal anatomic structures are clearly
defined and any changes in the normal anatomy and their relationships with specific anatomic structures are clearly
defined. Benign neoplasms such lipomas and leiomyomas can
be demonstrated along with their relationship to adjacent anal
canal structures. Lesions within the anal canal appear as
hypoechoic areas. Tissue diagnosis may be obtained with
ultrasound-directed needle biopsies when desired.
Anal canal malignancies are an uncommon cancer in the
gastrointestinal tract. Diagnosis requires appropriate clinical
salvage surgery for those patients who fail standard chemoradiation therapy.
Although clinical (digital) examination is important in the
assessment of squamous cell carcinoma of the anus, EAUS is
more precise in accurately measuring the actual size and circumferential involvement of the lesion. EAUS staging
(uTNM) of anal cancers corresponds to the TNM [UICC
(International Union Against Cancer)] staging (Table 7-3).
Tumor staging for anal cancer depends primarily on the maximal tumor diameter, which is accurately measured by EAUS.
Additionally, the depth of invasion of the lesion can be measured in relationship to the sphincter mechanism. The extent of
sphincter involvement can be determined and other staging
systems stage these lesions based on depth of invasion.
76,77
One such staging system is depicted in Table 7-4.77The eval-
4
112 D.G. Kim and W.D. Wong
ABLE 7-3. Ultrasound staging classification (uTNM) for anal canal
T
cancer
Primary tumor (T)
Tx Primary tumor cannot be assessed
T0 No evidence of primary tumor
Tis Carcinoma in situ
T1 Tumor 2 cm or less in greatest dimension
T2 Tumor more than 2 cm but no more than 5 cm in greatest dimension
T3 Tumor more than 5 cm in greatest dimension
T4 Tumor of any size that invades an adjacent organ(s), e.g., vagina,
urethra, bladder (involvement of the sphincter muscle(s) alone is not
classified as T4)
Regional lymph nodes (N)
Nx Regional lymph nodes cannot be assessed
N0 No regional lymph node metastasis
N1 Metastasis in perirectal lymph node(s)
N2 Metastasis in unilateral internal iliac and/or inguinal lymph node(s)
N3 Metastasis in perirectal and inguinal lymph nodes and/or bilateral
internal iliac and/or inguinal lymph nodes
Distant metastasis
Mx Distant metastasis cannot be assessed
M0 No distant metastasis
M1 Distant metastasis
TABLE 7-4. Ultrasound staging classification by depth of invasion
(uTNM) for anal canal cancer
uT1 Tumor confined to the submucosa
uT2a Tumor invades only the internal anal sphincter
uT2b Tumor penetrates into the external anal sphincter
uT3 Tumor invades through the sphincter complex and into the
perianal tissues
uT4 Tumor invades adjacent structures
FIGURE 7-17. This three-dimensional ultrasound image demonstrates
an anteriorly based rectal cancer that extends full-thickness through
the rectal wall (uT3). However, a clear hyperechoic plane can be
seen between the prostate gland and the rectal tumor, as depicted by
the arrows.
improved the understanding of three-dimensional imaging
and facilitated interpretation of the findings. In another small
uation of squamous cell carcinomas of the anus should
include an evaluation of the rectum with ERUS to determine
the presence of metastatic lymph nodes within the mesorectum. The mesorectum as well as the anal canal can also be
evaluated in follow-up after treatment. Any suspicious areas
detected during follow-up may be biopsied if necessary.
study of 33 patients comparing conventional ERUS to 3D-
ERUS, Kim et al.
79
reported no statistically significant differences in the two modalities in determining depth of invasion
or lymph node status. However, it is of interest to note that the
accuracy of 3D-ERUS was 90.9% for T2 lesions and 84.8%
for T3 lesions compared with 84.8% and 75.8% for conventional ultrasound. The accuracy of 3D-ERUS for predicting
Three-dimensional Ultrasound
Three-dimensional ultrasound allows for multiplanar imaging
of both the rectum and the anal canal. This new technology is
currently being evaluated to compare its efficacy relative to
conventional two-dimensional ultrasound as well as to other
modalities such as MRI. Three-dimensional ultrasound can be
used to assess anal fistulous tracts, to evaluate anal sphincter
injury, as well as to stage both rectal and anal tumors. An
example of a three-dimensional ERUS image (3D-ERUS) of
a rectal cancer is shown in Figure 7-17.
Hunerbein et al.
ultrasound with 3D-ERUS and endorectal MRI and reported
an accuracy for depth of wall invasion by rectal cancer of
84%, 88%, and 91%, respectively. Because of the small sample size, these differences were not statistically significant.
However, they believed that the additional scan planes
78
compared standard two-dimensional
lymph node status was 84.8% compared with 66.7% for conventional ERUS. They concluded that although there was no
statistical advantage, three-dimensional imaging made the
visualization of focal lesions and lymph nodes easier.
Three-dimensional EAUS has also been applied to benign
anal disorders such as anal sphincter injury and anal fistula
assessment. Several comparative studies have been reported
evaluating its efficacy and comparing 3D-EAUS with MRI.
West et al.
80
reported that 3D-EAUS and endoanal MRI were
comparable for detecting external sphincter defects. Gold
81
et al.
determined that 3D-EAUS revealed a direct relationship between the length of a sphincter tear and its radial extent.
In addition, they demonstrated marked gender differences in
anal sphincter configuration using three-dimensional ultrasound imaging. In the evaluation of anal fistula tracts, West
82
et al.
reported equivalency between 3D-EAUS and endoanal
MRI for the evaluation of anal fistula tracts. In a recent study
7. Endoluminal Ultrasound 113
by Buchanan et al.,833D-EAUS was found to be very accurate
in the assessment of both the internal opening and the primary
tract of an anal fistula. They reported an accuracy of 90% in
identifying the internal opening and an accuracy of 81% in
delineating the primary tract. Three-dimensional EAUS was
less accurate (68%) in identifying secondary tracts or extensions. In their study, the use of hydrogen peroxide did not
increase the accuracy but in some instances it did make the
tract and internal opening more conspicuous.
Summary
Endoluminal ultrasound has been shown to be extremely useful in the evaluation and management of many benign and
malignant anorectal conditions. ERUS has become the best
imaging technique to accurately stage rectal cancers and anal
canal tumors preoperatively. Moreover, ERUS can have a role
in the follow-up evaluation of these patients. EAUS is the
diagnostic test of choice in the evaluation of fecal incontinence and is used routinely. The EAUS has also been used to
help define complex anal fistulas to facilitate their management. The accuracy of diagnosis is operator dependent and
improves with experience. Endoluminal ultrasound has made
a major contribution to the understanding and management of
many anorectal conditions. Three-dimensional ultrasound
may prove to be advantageous, but requires further study.
References
1. Wild JJ, Reid JM. Diagnostic use of ultrasound. Br J Phys Med
1956;19(11):248–257.
2. Dragsted J, Gammelgaard J. Endoluminal ultrasonic scanning in
the evaluation of rectal cancer: a preliminary report of 13 cases.
Gastrointest Radiol 1983;8(4):367–369.
3. Hildebrandt U, Feifel G. Preoperative staging of rectal cancer by
intrarectal ultrasound. Dis Colon Rectum 1985;28(1):42–46.
4. Greene FL, et al., ed. AJCC Cancer Staging Manual. 6th ed. New
York: Springer; 2002.
5. Beynon J, et al. The endosonic appearances of normal colon and
rectum. Dis Colon Rectum 1986;29(12):810–813.
6. Deen KI, Madoff RD, Wong WD. Preoperative staging of rectal
neoplasms with endorectal ultrasonography. Semin Colon Rectal
Surg 1995;6:78–85.
7. Garcia-Aguilar J, et al. Accuracy of endorectal ultrasonography
in preoperative staging of rectal tumors. Dis Colon Rectum
2002;45(1):10–15.
8. Pikarsky A, et al. The use of rectal ultrasound for the correct
diagnosis and treatment of rectal villous tumors. Am J Surg
2000;179(4):261–265.
9. Worrell S, et al. Endorectal ultrasound detection of focal carcinoma within rectal adenomas. Am J Surg 2004;187(5):625–629.
10. Kim DG, Madoff RD. Transanal treatment of rectal cancer: ablative methods and open resection. Semin Surg Oncol
1998;15(2):101–113.
11. Beynon J, et al. Preoperative assessment of mesorectal lymph
node involvement in rectal cancer. Br J Surg 1989;76(3):
276–279.
12. Rifkin MD, Ehrlich SM, Marks G. Staging of rectal carcinoma:
prospective comparison of endorectal US and CT. Radiology
1989;170(2):319–322.
13. Orrom WJ, et al. Endorectal ultrasound in the preoperative staging of rectal tumors. A learning experience. Dis Colon Rectum
1990;33(8):654–659.
14. Milsom JW, Graffner H. Intrarectal ultrasonography in rectal
cancer staging and in the evaluation of pelvic disease. Clinical
uses of intrarectal ultrasound. Ann Surg 1990;212(5):602–606.
15. Pappalardo G, et al. The value of endoluminal ultrasonography
and computed tomography in the staging of rectal cancer: a preliminary study. J Surg Oncol 1990;43(4):219–222.
16. Thaler W, et al. Preoperative staging of rectal cancer by endoluminal ultrasound vs. magnetic resonance imaging. Preliminary
results of a prospective, comparative study. Dis Colon Rectum
1994;37(12):1189–1193.
17. Tio TL, Tytgat GN. Endoscopic ultrasonography in analysing
peri-intestinal lymph node abnormality. Preliminary results of
studies in vitro and in vivo. Scand J Gastroenterol Suppl
1986;123:158–163.
18. Hildebrandt U, et al. Endosonography of pararectal lymph
nodes. In vitro and in vivo evaluation. Dis Colon Rectum 1990;
33(10):863–868.
19. Herrera-Ornelas L, et al. Metastases in small lymph nodes from
colon cancer. Arch Surg 1987;122(11):1253–1256.
20. Katsura Y, et al. Endorectal ultrasonography for the assessment
of wall invasion and lymph node metastasis in rectal cancer. Dis
Colon Rectum 1992;35(4):362–368.
21. Akasu T, et al. Limitations and pitfalls of transrectal ultrasonography for staging of rectal cancer. Dis Colon Rectum 1997;40(10
suppl):S10–15.
22. Sunouchi K, et al. Small spot sign of rectal carcinoma by
endorectal ultrasonography: histologic relation and clinical
impact on postoperative recurrence. Dis Colon Rectum 1998;
41(5):649–653.
23. Sunouchi K, et al. Limitation of endorectal ultrasonography:
what does a low lesion more than 5 mm in size correspond to histologically? Dis Colon Rectum 1998;41(6):761–764.
24. Solomon MJ, McLeod R.S. Endoluminal transrectal ultrasonography: accuracy, reliability, and validity. Dis Colon Rectum
1993;36(2):200–205.
25. Glaser F, Schlag P, Herfarth C. Endorectal ultrasonography for
the assessment of invasion of rectal tumours and lymph node
involvement. Br J Surg 1990;77(8):883–887.
26. Kruskal JB, et al. Pitfalls and sources of error in staging rectal
cancer with endorectal US. Radiographics 1997;17(3):609–626.
27. Bernini A, et al. Preoperative adjuvant radiation with chemotherapy for rectal cancer: its impact on stage of disease and the
role of endorectal ultrasound. Ann Surg Oncol 1996;3(2):
131–135.
28. Fleshman JW, et al. Accuracy of transrectal ultrasound in predicting pathologic stage of rectal cancer before and after preoperative radiation therapy. Dis Colon Rectum 1992;35(9):
823–829.
29. Meade PG, et al. Preoperative chemoradiation downstages
locally advanced ultrasound-staged rectal cancer. Am J Surg
1995;170(6):609–612; discussion 612–613.
30. Rau B, et al. Accuracy of endorectal ultrasound after preoperative radiochemotherapy in locally advanced rectal cancer. Surg
Endosc 1999;13(10):980–984.
114 D.G. Kim and W.D. Wong
31. Williamson PR, et al. Endorectal ultrasound of T3 and T4 rectal
cancers after preoperative chemoradiation. Dis Colon Rectum
1996;39(1):45–49.
32. Brown CL, et al. Response to preoperative chemoradiation in
stage II and III rectal cancer. Dis Colon Rectum 2003;46(9):
1189–1193.
33. Michelassi F, et al. Local recurrence after curative resection of
colorectal adenocarcinoma. Surgery 1990;108(4):787–792; discussion 792–793.
34. Sagar PM, Pemberton JH. Surgical management of locally recurrent rectal cancer. Br J Surg 1996;83(3):293–304.
35. Beynon J, et al. The detection and evaluation of locally recurrent
rectal cancer with rectal endosonography. Dis Colon Rectum
1989;32(6):509–517.
36. de Anda EH, et al. Endorectal ultrasound in the follow-up of rectal cancer patients treated by local excision or radical surgery.
Dis Colon Rectum 2004;47(6):818–824.
37. Mascagni D, et al. Endoluminal ultrasound for early detection of
local recurrence of rectal cancer [see comment]. Br J Surg
1989;76(11):1176–1180.
38. Ramirez JM, et al. Endoluminal ultrasonography in the followup of patients with rectal cancer. Br J Surg 1994;81(5):692–694.
39. Rotondano G, et al. Early detection of locally recurrent rectal
cancer by endosonography. Br J Radiol 1997;70(834):567–571.
40. Tjandra JJ, et al. Endoluminal ultrasound defines anatomy of the
anal canal and pelvic floor. Dis Colon Rectum 1992;35(5):
465–470.
41. Sentovich SM, Wong WD, Blatchford GJ. Accuracy and reliability of transanal ultrasound for anterior anal sphincter injury.
Dis Colon Rectum 1998;41(8):1000–1004.
42. Rieger N, Tjandra J, Solomon M. Endoanal and endorectal ultrasound: applications in colorectal surgery. ANZ J Surg 2004;
74(8):671–675.
43. Tjandra JJ, et al. Endoluminal ultrasound is preferable to electromyography in mapping anal sphincteric defects. Dis Colon
Rectum 1993;36(7):689–692.
44. Mellgren A, et al. Long-term cost of fecal incontinence secondary to obstetric injuries. Dis Colon Rectum 1999;42(7):857–865;
discussion 865–867.
45. Allen RE, et al. Pelvic floor damage and childbirth: a neurophysiological study [see comment]. Br J Obstet Gynaecol 1990;
97(9):770–779.
46. Sultan AH, et al. Anal-sphincter disruption during vaginal delivery [comment]. N Engl J Med 1993;329(26):1905–1911.
47. Poen AC, et al. Third-degree obstetric perineal tear: long-term
clinical and functional results after primary repair. Br J Surg
1998;85(10):1433–1438.
48. Sorensen M, et al. Sphincter rupture in childbirth. Br J Surg
1993;80(3):392–394.
49. Tetzschner T, et al. Anal and urinary incontinence in women with
obstetric anal sphincter rupture [see comment]. Br J Obstet
Gynaecol 1996;103(10):1034–1040.
50. Burnett SJ, et al. Unsuspected sphincter damage following childbirth revealed by anal endosonography. Br J Radiol 1991;
64(759):225–227.
51. Varma A, et al. Obstetric anal sphincter injury: prospective evaluation of incidence [see comment]. Dis Colon Rectum
1999;42(12):1537–1543.
52. Zetterstrom J, et al. Effect of delivery on anal sphincter morphology and function. Dis Colon Rectum 1999;42(10):1253–1260.
53. Sultan AH, Kamm MA, Hudson CN, Bartram CI. Effect of pregnancy on anal sphincter morphology and function. Int J
Colorectal Dis 1993;8(4):206–209.
54. Willis S, Faridi A, Schelzig S, et al. Childbirth and incontinence:
a prospective study on anal sphincter morphology and function
before and early after vaginal delivery. Langenbecks Arch Surg
2002;387(2):101–107.
55. Tsang CB, et al. Anal sphincter integrity and function influences
outcome in rectovaginal fistula repair. Dis Colon Rectum
1998;41(9):1141–1146.
56. Deen KI, et al. Anal sphincter defects. Correlation between
endoanal ultrasound and surgery. Ann Surg 1993;218(2):201–205.
57. Falk PM, et al. Transanal ultrasound and manometry in the evaluation of fecal incontinence. Dis Colon Rectum 1994;37(5):468–472.
58. Farouk R, Bartolo DC. The use of endoluminal ultrasound in the
assessment of patients with faecal incontinence. J R Coll Surg
Edinb 1994;39(5):312–318.
59. Zetterstrom JP, et al. Perineal body measurement improves evaluation of anterior sphincter lesions during endoanal ultrasonography. Dis Colon Rectum 1998;41(6):705–713.
60. deVries PA, Pena A. Posterior sagittal anorectoplasty. J Pediatr
Surg 1982;17(5):638–643.
61. Jones NM, et al. The value of anal endosonography compared
with magnetic resonance imaging following the repair of anorectal malformations. Pediatr Radiol 2003;33(3):183–185.
62. Simmang CL, et al. Posterior sagittal anorectoplasty in adults:
secondary repair for persistent incontinence in patients with
anorectal malformations. Dis Colon Rectum 1999;42(8):
1022–1027.
63. Gilliland R, et al. Pudendal neuropathy is predictive of failure
following anterior overlapping sphincteroplasty. Dis Colon
Rectum 1998;41(12):1516–1522.
64. Donnelly V, et al. Obstetric events leading to anal sphincter damage. Obstet Gynecol 1998;92(6):955–961.
65. Solomon MJ, et al. Assessment of peripouch inflammation after
ileoanal anastomosis using endoluminal ultrasonography. Dis
Colon Rectum 1995;38(2):182–187.
66. Deen KI, et al. Fistulas in ano: endoanal ultrasonographic assessment assists decision making for surgery. Gut 1994;35(3):
391–394.
67. Cataldo PA, Senagore A, Luchtefeld MA. Intrarectal ultrasound
in the evaluation of perirectal abscesses. Dis Colon Rectum
1993;36(6):554–558.
68. Law PJ, et al. Anal endosonography in the evaluation of perianal
sepsis and fistula in ano. Br J Surg 1989;76(7):752–755.
69. Lengyel AJ, Hurst NG, Williams JG. Pre-operative assessment
of anal fistulas using endoanal ultrasound. Colorectal Dis
2002;4(6):436–440.
70. Cheong DM, et al. Anal endosonography for recurrent anal fistulas: image enhancement with hydrogen peroxide. Dis Colon
Rectum 1993;36(12):1158–1160.
71. Poen AC, et al. Hydrogen peroxide-enhanced transanal ultrasound in the assessment of fistula-in-ano. Dis Colon Rectum
1998;41(9):1147–1152.
72. Navarro-Luna A, et al. Ultrasound study of anal fistulas with
hydrogen peroxide enhancement. Dis Colon Rectum 2004;
47(1):108–114.
73. Goldman S, et al. Transanorectal ultrasonography in the staging
of anal epidermoid carcinoma. Int J Colorectal Dis 1991;6(3):
152–157.
7. Endoluminal Ultrasound 115
74. Herzog U, Boss M, Spichtin HP. Endoanal ultrasonography in
the follow-up of anal carcinoma. Surg Endosc 1994;8(10):
1186–1189.
75. Roseau G, et al. Endoscopic ultrasonography in the staging and
follow-up of epidermoid carcinoma of the anal canal.
Gastrointest Endosc 1994;40(4):447–450.
76. Giovannini M, et al. Anal carcinoma: prognostic value of
endorectal ultrasound (ERUS). Results of a prospective multicenter study. Endoscopy 2001;33(3):231–236.
77. Tarantino D, Bernstein MA. Endoanal ultrasound in the staging
and management of squamous-cell carcinoma of the anal canal:
potential implications of a new ultrasound staging system. Dis
Colon Rectum 2002;45(1):16–22.
78. Hunerbein M, et al. Prospective comparison of endorectal ultrasound, three-dimensional endorectal ultrasound, and endorectal
MRI in the preoperative evaluation of rectal tumors. Preliminary
results. Surg Endosc 2000;14(11):1005–1009.
79. Kim JC, et al. Comparative study of three-dimensional and conventional endorectal ultrasonography used in rectal cancer staging. Surg Endosc 2002;16(9):1280–1285.
80. West RL, Dwarkasing S, Briel JW, et al. Can three-dimensional
endoanal ultrasonography detect external anal sphincter atrophy?
A comparison with endoanal magnetic resonance imaging. Int J
Colorectal Dis 2005;20(4):328–333.
81. Gold DM, et al. Three-dimensional endoanal sonography in
assessing anal canal injury. Br J Surg 1999;86(3):365–370.
82. West RL, et al. Hydrogen peroxide-enhanced three-dimensional
endoanal ultrasonography and endoanal magnetic resonance
imaging in evaluating perianal fistulas: agreement and patient
preference. Eur J Gastroenterol Hepatol 2004;16(12):1319–1324.
83. Buchanan GN, et al. Value of hydrogen peroxide enhancement of
three-dimensional endoanal ultrasound in fistula-in-ano. Dis
Colon Rectum 2005;48(1):141–147.
84. Romano G, et al. Intrarectal ultrasound and computed tomography in the pre- and postoperative assessment of patients with rectal cancer. Br J Surg 1985;72(suppl):S117–119.
85. Hildebrandt U, et al. Endorectal ultrasound: instrumentation and
clinical aspects. Int J Colorectal Dis 1986;1(4):203–207.
86. Holdsworth PJ, et al. Endoluminal ultrasound and computed
tomography in the staging of rectal cancer. Br J Surg 1988;
75(10):1019–1022.
87. Beynon J. An evaluation of the role of rectal endosonography in
rectal cancer. Ann R Coll Surg Engl 1989;71(2):131–139.
88. Dershaw DD. Endorectal sonography for rectal carcinoma. Bull
NY Acad Med 1990;68(3):411–419.
89. Glaser F, et al. Influence of endorectal ultrasound on surgical
treatment of rectal cancer. Eur J Surg Oncol 1990;16(4):304–311.
90. Jochem RJ, et al. Endorectal ultrasonographic staging of rectal
carcinoma. Mayo Clin Proc 1990;65(12):1571–1577.
91. Herzog U, et al. How accurate is endorectal ultrasound in the
preoperative staging of rectal cancer? Dis Colon Rectum
1993;36(2):127–134.
92. Sentovich SM, et al. Transrectal ultrasound of rectal tumors. Am
J Surg 1993;166(6):638–641; discussion 641–642.
93. Adams DR, et al. Use of preoperative ultrasound staging for treatment of rectal cancer. Dis Colon Rectum 1999;42(2):159–166.
94. Marusch F, et al. Routine use of transrectal ultrasound in rectal
carcinoma: results of a prospective multicenter study. Endoscopy
2002;34(5):385–390.
95. Manger T, Stroh C. Accuracy of endorectal ultrasonography in
the preoperative staging of rectal cancer. Tech Coloproctol
2004;8(suppl 1):14–15.
8
Preoperative Management—Risk
Assessment, Medical Evaluation,
and Bowel Preparation
Conor P. Delaney and John M. MacKeigan
Preparation of the patient for surgery is a vital component of
optimizing recovery after surgery, and must be individually
tailored to the medical status of the patient.
undergo colorectal surgery may present in normal health,
such as in a young patient undergoing hemorrhoid surgery, or
may present in extreme ill health, such as the octogenarian
with multiple medical conditions, who has developed perforated diverticulitis. Preoperative assessment and medical
intervention are important components of care, and may
account for the difference in perioperative mortality noted
after abdominal and colorectal surgery between the United
States and some European countries.
Since the initial studies by Tyson and Spaulding in the
1950s, preparation of the bowel before surgery has been considered an essential component of care. More recently, this
has become a contentious issue, and metaanalyses have suggested that bowel preparation provides no benefit, and may
actually increase the incidence of some complications.
This chapter addresses the issues of medical evaluation and
bowel preparation before surgery. These are considered on the
background of reviewing some of the more important scoring
systems for risk assessment before surgery, which permit
comparison among different surgeons, institutions, and care
pathways.
2
1
Patients who
Perioperative Risk Assessment
Scoring Systems
The risk related to surgery is a function of many factors.
Patient-related factors include the underlying disease
processes and the patient’s physical ability to tolerate the
physiologic stress related to the surgical procedure.
Increasing amounts of data now show that risk is also affected
by the volume of a procedure performed at the medical institution, but perhaps most importantly by the experience, training, and volume of surgery performed by the individual
surgeon.
Scoring systems assess the patients’ risk for morbidity and
mortality as a result of anesthesia and surgery. These systems
generally use data acquired during pre-hospital and in-hospital
care, and some supplement this with components measuring
operative severity. Some classification systems are designed
to allow comparison of results between institutions and surgeons, whereas others are designed to distinguish patients
who subsequently will have postoperative adverse events
from those who will not.
tors on overall morbidity and mortality is currently unknown
but an ideal risk scoring system would incorporate all of these
factors allowing accurate evaluation of surgical risk to the
patient.
Thus, a primary aim of a scoring system is the evaluation
of therapeutic benefit, i.e., the ratio of the relative harm and
the relative benefit that are likely to follow a specific operation for a specific illness, whether in a specific patient, institution, or health system. Parameters that are useful in this
evaluation include the natural history of the disease process,
and the urgency of a specific procedure. Age may have an
influence on operative risk, as many elderly patients require
concurrent management of multiple organ degenerative disease. Elderly patients often tolerate operations well but complications poorly, hence prediction of the potential morbidity
of an operation is particularly important in this group of
patients. Scoring systems also provide a useful means of comparing outcomes from different institutions and patient groups
by correcting for different comorbidities. Various scoring systems have been developed in an effort to quantify the risk of
a patient from disease or intervention, and systems can be
classified as preoperative or physiologic (Table 8-1).
Some scores are useful in predicting outcomes in specific
conditions, such as Ranson’s for pancreatitis, Child for liver
failure, and the Burns index, but they are not of use for the
general assessment of patients with other disorders. Some
studies have tried to predict risk in a less specific manner, and
have suggested that a surgeon’s gut feeling upon completion
of a major procedure may be a good indicator of subsequent
outcome.
5
3,4
The influence of each of these fac-
116
8. Preoperative Management—Risk Assessment, Medical Evaluation, and Bowel Preparation 117
TABLE 8-1. Perioperative scoring systems (references in text)
Physiologic scores Preoperative scores
APACHE (I and II) ASA grading
E-PASS Goldman cardiac risk index
ISS/TRISS Hospital prognostic index
POSSUM Prognostic nutritional index
P-POSSUM Pulmonary complication risk
SAPS
Sepsis score
Sickness score
Therapeutic intervention score
Risk Assessment for Complications from
Specific Organ Systems
Some scoring systems define patient characteristics that are
associated with increased morbidity and mortality because of
involvement of a particular organ system. Scoring systems
that have been described to predict the risk of death include
those for respiratory,
disease.
11,12
Cardiac Risk
Goldman Cardiac Risk
The Goldman risk model is probably the best-accepted model
for pure determination of cardiac risk for surgery. Point scores
are assigned to each of nine clinical factors and patients are
divided into four risk classes based on the total point score
(Table 8-2). This is an important score because it reminds clinicians of the major cardiac risk factors in noncardiac surgery.
Although the system is easy to use and utilizes relative
weighting of risk factors, it was designed in the 1970s, and
has not been updated for modern practice in anesthesia, medicine, or surgery. Cardiac risk for patients undergoing noncardiac surgery has also been evaluated by other studies.
TABLE 8-2. Goldman cardiac risk index
Cardiac risk event Points
Myocardial infarction within 6 mo 10
Age >70 y 5
S3 gallop or jugular venous distension 11
Important aortic valve stenosis 3
Rhythm other than sinus, or sinus rhythm and atrial premature
contractions on last preoperative electrocardiogram 7
More than five premature ventricular contractions per
minute anytime before surgery 7
Poor general medical status 3
Intraperitoneal, intrathoracic, or aortic operation 3
Emergency operation 4
Class Points complication risk (%) risk (%)
I 0–5 0.7 0.2
II 6–12 5 2
III1 3–25 11 2
IV ≥26 22 56
6
gastrointestinal,
13
Life-threatening Cardiac death
7–10
and cardiovascular
11,12
Respiratory Risk
Pulmonary Complication Risk
Findings on respiratory examination, chest X-ray, Goldman’s
cardiac risk index, and the Charlson comorbidity index have
been used for predicting respiratory complications.
6
Risk Assessment for Postoperative Morbidity
and Mortality
American Society of Anesthesiologists Classification
The American Society of Anesthesiologists (ASA) classification system (Table 8-3)
thesiologists to preexisting diseases. Because of the ease of
use, and the fact that no tests are required, it has also been
used to estimate operative risk.
lates with perioperative mortality and morbidity
correlates significantly with perioperative variables such as
intraoperative blood loss, duration of postoperative ventilation, and duration of intensive care unit (ICU) stay.
severity of operative procedure, higher ASA class, symptoms
of respiratory disease, and malignancy predicted postoperative morbidity in one study.
Disadvantages to using the ASA score are that the score
awarded depends on the subjective clinical judgment of the
attending anesthesiologist, and that the small numbers of
groups available means there can be little meaningful comparison between different surgeons or institutions.
Prognostic Nutritional Index
The prognostic nutritional index (PNI) was devised21to predict complication risk based on mortality, and correlates with
postoperative sepsis and death. The PNI uses four factors,
namely, serum albumin level, serum transferrin level, triceps
skinfold thickness, and cutaneous delayed-type hypersensitivity. Serum albumin level, serum transferrin level, and delayed
hypersensitivity were the only accurate predictors of postoperative morbidity and mortality. In addition to predicting postoperative morbidity and mortality, PNI can be used for
predicting patients who might need nutritional support in the
perioperative period. The authors concluded that perioperative nutritional support might reduce operative morbidity and
mortality in malnourished patients, although this has not been
routinely agreed with in the literature.
TABLE 8-3. ASA classification scheme
I Normal healthy patient
II Mild systemic disease
III Severe, noncapacitating systemic disease
IV Incapacitating systemic disease, threatening life
V Moribund, not expected to survive 24 h
E Emergency
14
was initially developed to alert anes-
15,16
ASA class directly corre-
20
17–19
and also
19
The
118 C.P. Delaney and J.M. MacKeigan
APACHE (Acute Physiology and Chronic Health
Evaluation) Scoring Systems
APACHE was initially described in 198122and subsequently
replaced in 1985
designed primarily for patients in the ICU but has been used
for the assessment of patients with severe trauma, abdominal
sepsis, postoperative enterocutaneous fistulas, acute pancreatitis, and to predict postoperative outcome.
advantage is that it is not independent of the effects of
treatment, thus scoring for emergency patients being admitted
to the ICU is best performed before surgical intervention.
Other disadvantages are that it is relatively complex and does
not take into consideration the nutritional status of the patient
or cardiology findings that add to operative risk. APACHE
scores also do not take into account the extent of surgery. The
APACHE III has been proposed more recently, but it is also
very complex for routine use.
tems have also been developed from the APACHE system.
These include SAPS (simplified acute physiology score),
which uses 14 of the 34 variables, and SAPS II, which also
takes into consideration the urgency of the procedure and any
associated chronic medical illness.
23
by APACHE II. This score was initially
24
The main dis-
26
Several simpler scoring sys-
POSSUM
The POSSUM (Physiological and Operative Severity Score
for enUmeration of Mortality and morbidity) was developed
by multivariate discriminant analysis
prospective data, primarily to permit surgical audit for assessment of quality of care. It has been suggested that it works
independent of geographical factors, and several publications
have now come from the United States suggesting that it may
also have a role in this health care system.
POSSUM calculates expected death and expected morbidity
rates based on 12 physiologic variables and six operative variables each of which are scored 1, 2, 4, or 8 (Table 8-4). The
major advantage is that it predicts both morbidity and mortality and has successfully been used for a comparative audit of
performance among surgical units, hospitals, and countries.
Disadvantages include that it does not take into account differences among surgeons, anesthetists, and operating time, all of
which may influence outcome. This is because POSSUM was
TABLE 8-4. Parameters for calculation of the POSSUM score
Physiologic parameters Operative parameters
Age (y) Operative severity
Cardiac signs/chest X-ray Multiple procedures
Respiratory signs/chest X-ray Total blood loss (mL)
Pulse rate Peritoneal soiling
Systolic blood pressure (mm Hg) Presence of malignancy
Glasgow coma score Mode of surgery
Hemoglobin (g/dL)
White cell count (×10
Urea concentration (mmol/L)
+
and K+levels (mmol/L)
Na
Electrocardiogram
12
/l)
28
of retrospective and
2,29
developed as a scoring system for audit, so other factors may
need to be considered when using POSSUM for risk assessment of patients for surgery. POSSUM also does not use primary diagnosis as a factor for scoring. Nevertheless,
comparison of APACHE II with POSSUM showed that POSSUM is superior in predicting mortality in patients admitted to
a high-dependency unit after general surgery.
30
Portsmouth Modification of POSSUM (P-POSSUM)
One concern with POSSUM has been that it may overpredict
25
mortality and morbidity rates by up to six times with a minimum mortality of 1.1%. P-POSSUM was therefore developed
using a different mathematical formula to counter these disadvantages,
31
with the minimum mortality score in P-POSSUM
reduced to 0.2%. Whereas some studies found that both scoring systems overpredicted mortality rates for vascular surgery
patients,
dictor of mortality and morbidity than POSSUM for vascu-
27
lar,
32,33
others found that P-POSSUM was a better pre-
34
gastrointestinal,35and laparoscopic colorectal surgery.
Other Scoring Systems
Various other scoring systems have also been developed primarily for assessment of critically ill patients in the ICU and
for trauma and sepsis, and these are listed in Table 8-1.
Risk Assessment for Colorectal Disease
Preoperative pulmonary and nutritional problems have been
significant contributing factors in patients who died from sepsis after colon resection in the elderly. Others have suggested
that age, congestive heart failure, hepatic, renal or pulmonary
impairment, and extent of involvement by malignancy and
postoperative complications were associated with greater
mortality after colon surgery. Subsequently, it has been
reported that age influenced mortality but not 5-year sur-
46
vival.
ety of preoperative risk factors on operative outcomes and
2
Ondrula et al.47assessed the predictive value of a vari-
defined a colon index that assessed patients’ operative risk.
More recently, POSSUM was found to allow a realistic comparison of performance of different units performing colorectal resection and also permit comparison of outcome after
colorectal resection among different surgeons.
48,49
has also been reported in patients undergoing laparoscopic
colectomy
29
but even the P-POSSUM overpredicted mortality
and morbidity. Further modifications may be required to provide a validated tool for comparisons between laparoscopic
and open approaches to colorectal resection.
Preoperative Medical Evaluation
Once a patient has a diagnosis requiring colorectal surgery,
most surgeons intuitively categorize them into those needing
minimal assessment, or extensive medical evaluation and
36
37–45
POSSUM
8. Preoperative Management—Risk Assessment, Medical Evaluation, and Bowel Preparation 119
treatment before surgery. Young patients having minor surgery will require no assessment. Young patients having more
significant surgery may require minor evaluation, whereas
older patients having minor surgery may require a similar
level of evaluation. Older patients, and those with more extensive comorbidities will require assessment and possible treatment before surgery. Few definite guidelines exist as to who
requires any exact pattern of assessment, and the benefits of
individual tests are described below.
At the Cleveland Clinic, a questionnaire called Health
Quest is given to patients who complete this on-line. Based on
their answers, a score of 1–5 is generated indicating a level of
complexity of medical history that can help stratify patients
for level of preoperative assessment.
50
This process is also
associated with a reduction in preoperative surgical delay, and
increased patient satisfaction.
Evaluation is performed with a combination of history,
physical examination, and selected investigations. In a large
prospective clinical-epidemiologic study, Arvidsson and col-
3
leagues
found that a standardized assessment before surgery,
by a combination of questionnaires, interview, physical examination, and laboratory screening identified a high proportion
of patients who were likely to have an adverse event in the
postoperative period.
Preanesthesia Interview
Of the techniques available that are used in preoperative evaluation of patients, namely, history, physical examination, and
investigations, history taking is the most efficient and prof-
3,51
itable.
including history of anesthesia and surgery helps identify
many potential problems that can occur perioperatively.
Questionnaires have previously been found to be efficient and
reliable for anesthesia preadmission assessment.
operative questionnaire is suitable for patients undergoing
daycare surgery, because most of these patients are at low risk.
History taking should include information on the condition
for which the procedure is being performed, history of surgical
procedures (local procedures that may complicate surgery such
as reoperative pelvic surgery, as well as general procedures that
may complicate recovery such as prior splenectomy), and prior
outcomes with intubation and anesthesia. Special consideration
should be given to cardiopulmonary function, allergy, renal and
hepatic function, bleeding tendency, and medication use.
History of chronic medical conditions of the cardiorespiratory
system and medications including dosage is important. In children, history should be focused on other specific factors such as
birth history and history of recent infections, especially pneumonia and upper respiratory tract infections. Aspirin and other
nonsteroidal anti-inflammatory drugs are best discontinued
1 week before surgery. Other questions should pertain to immunization, smoking, and alcohol and drug use. Cessation of
smoking 8 or more weeks before surgery helps optimize the
mucociliary apparatus of the patient before surgery. Review of
A thorough review of previous medical records
52
Thus, a pre-
functional status of the patient, activities of daily living (ADL),
and social support are also important, although this primarily
relates to longer term recovery, hospital stay, and likely discharge status from hospital, rather than direct perioperative
morbidity and mortality.
History taking for cardiac assessment has been reasonably
well standardized, and very well reviewed recently by
53
Mukherjee and Eagle.
The primary factors to be considered
are whether the patient has recent myocardial infarction,
decompensated heart failure, unstable angina, symptomatic
arrhythmias, or symptomatic valvular heart disease. In general, noninvasive testing is most effective in intermediate-risk
patients, whereas invasive evaluation should be considered in
those with multiple risk factors and ischemia on preoperative
testing, because perioperative beta-blockade may be inadequate.
Formal anesthetic evaluation is also needed for many
patients. Similar to the selective levels of medical work-up,
not all patients will need to be seen by an anesthesiologist
preoperatively. Young, healthy patients with normal anatomy,
and no adverse findings in history or examination, may not
need any evaluation. Patients having more major surgery
should probably all meet the anesthesia service before surgery, for assessment as well as instruction about what will
happen around the time of surgery. This may be expediently
performed by nurse practitioners. Some patients with complex anesthetic histories or with major perioperative risk factors may require formal anesthetic assessment by a staff
anesthesiologist. Usually, such guidelines are institutionspecific, but it is recommended that the surgeon and anesthesiologist have a similar plan for assessment, so that
unexpected surprises are avoided on the day of surgery.
Physical Examination
A review of preoperative evaluation54noted that history and
physical examination focusing on risk factors for cardiac, pulmonary, and infectious complications and determination of a
patient’s functional capacity are important for preoperative
evaluation of patients. General indicators of fitness of a
patient for surgery include activities of daily living competence (ADL) and general mobility. Specific evaluation for
subtle signs of cardiopulmonary dysfunction is important,
because these have been shown to correlate strongly with
major perioperative complications.
13
Preoperative Tests
Preoperative tests serve to complement the history and physical examination in assessing the suitability of the patient for
surgery. They have been used to assess levels of known disease, detect unsuspected but modifiable conditions that may
be treated to reduce risk before surgery, or detect unsuspected
conditions that may not be possible to treat, and therefore
simply be baseline results before surgery.
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