肛直肠疾病.doc

重庆医科大学临床学院教案讲稿

重庆医科大学临床学院教案及讲稿
（教 案）
课程名称
普外科学
年级
07留学生
授课专业
胃肠外科
教 师
唐华
职称
副教授
授课方式
大课 示教
学时
3
题目章节

Diseases of the Anorectum

教材名称

作者

出 版 社

版次

教
学
目
的
要
求

掌握直肠癌、肛瘘、肛裂、肛周脓肿以及痔等常见肛直肠疾病的诊断与治疗措施。
教
学
难
点

1、直肠癌手术方式的选择
2、常见肛直肠疾病的鉴别诊断
教
学
重

点
1、 直肠癌临床表现、诊断方法和手术方式的选择。
2、 常见肛直肠疾病的诊断与鉴别诊断。
外语要求
全英文教学
教学方法手段
大课、多媒体、PBL
参考资料

TEXTBOOK OF SURGERY;Fifteenth Edition;DAVID C.SABISTON,JR.,M.D.
教研室意见

教学组长： 教研室主任：
年 月 日

8
制表时间：2/5/2025

辅助手段
时间分配
（讲 稿）
Surgical Anatomy and Physiology
The anatomic key to the anorectum is the pectinate line.Above it pain sensation is absent,blood drains to the portal and caval system,and lymph drains along the superior rectal vessels or lateral to the obturator or iliac nodes.Below the pectinate line,pain is notably present,blood drains to the inferior vena cava,and lymph to the inguinal nodes.
Anal glands empty into anal crypts at the pectinate line.When obstructed or infected,these glands become the source of abscess and fistulas.
Diseases of the Anorectum
Hemorrhoids
Anal fissure
Anorectal abscess
Anorectal fistulas
Rectal prolapse
Anorectal cancer
Common positions for digital examination
Side-lying position
Knee-chest position
Lithotomy position
Squatting position
Anterior flexion position
Hemorrhoids
Essentials of diagnosis:(emphasis)
Rectal bleeding,protrusion,discomfort.
Mucoid discharge from rectum.
Possible secondary anemia.
Characteristic findings on external anal inspection and anoscopic examination.
General considerations
Hemorrhoids (meaning flowing blood) represent a normal anatomic state and occur in all adults.
Only when hemorrhoids become enlarged and symptomatic is treatment indicated.
Hemorrhoids are classified as internal or external.
Internal hemorrhoids are a plexus of superior hemorrhoidal veins above the mucocutane-ous junction which are covered by mucosa.
External hemorrhoids (inferior hemorrhoidal plexus) occur below the mucocutaneous junction in the tissues beneath the anal epithelium of the anal canal and the skin of the perianal region.
Hemorrhoids become symptomatic for many reasons.The most common cause is straining in the squatting position at the time of bowel movement.
Other important causative factors of symptomatic hemorrhoids include chronic constipation,pregnancy,obesity,the low-fiber diet ,etc.
Clinical Findings
A.Symptoms and signs:
1.Bleeding
2.Protrude (prolapse)
3.Discomfort and pain:occur only when there is extensive thrombosis with edema and inflammation.
B.Examination:
External hemorrhoids may be seen on inspection,particularly if they are thrombosed.
If internal hemorrhoids are prolapsed,the redundant covering of mucin-secreting epithelium will be observed in one or several quadrants. Prolapse can be produced when the physician asks the patient to strain while the buttocks are gently spread.
On digital examination of rectum, internal hemorrhoids usually cannot be felt,and they should not be tender.
Anoscopic examination is necessary to see internal hemorrhoids that do not protrude. Proctosigmoidoscopy must be done to exclude inflammatory or malignant disease at a higher level.
Differential Diagnosis
Rectal bleeding,the most common manifes-tation of internal hemorrhoids ,also occurs with carcinoma of the colon and rectum, diverticular disease, adenomatous polyps,ulcerative colitis,and other less common diseases of the colon and rectum.
Sigmoidoscopic examination must be performed.
Barium enema X-ray studies and colonoscopy should be ordered selectively,depending on symptoms and findings.
Complications
Rarely,prolapsed internal hemorrhoids become irreducible because of congestion,edema,and thrombosis.
Hemorrhoids may serve as a portasystemic shunt in portal hypertension,and bleeding in this situation can be profuse.
Treatment
The treatment of symptomatic internal hemorrhoids must be individualized.
Hemorrhoids are normal,and therefore the goal of treatment is not to obliterate hemorrhoidal plexuses but rather to render the patient asymptomatic.
For this reason, hemorrhoidectomy is done less often today,and other modalities of treatment are more frequently used.
Treatment is based on the presenting findings according to the following classification:
First-degree:internal hemorrhoids cause painless,bright red rectal bleeding at the time of defecation.At this early stage,there is no prolapse, and anoscopic examination reveals enlarged hemorrhoids projecting into the lumen.
Second-degree:hemorrhoids protrude through the anal canal on gentle straining but spontaneously reduce.
Third-degree:hemorrhoids protrude with straining and must be reduced manually after defecation.
Fourth-degree:hemorrhoids is fixed protrusion.
A.Medical treatment:Most patients with early hemorrhoids (first- and second-degree) can be managed by simple local measures and dietary advice.
B.Injection treatment:a form of sclerotherapy
C.Rubber band ligation
D.Cryosurgery
E.Hemorrhoidectomy
F.Other operative procedures:
PPH(procedure for prolapse and hemorrhoids)
Anal Fissure
Essential of Diagnosis
nSymptoms:
Rectal pain related to defecation
Bleeding
Constipation
Signs:
Ulceration of anal canal
Hypertrophic anal papilla
Sentinel pile
Spasm of sphincter
Anal tenderness
Stenosis
General considerationsn
Fissures represent denuded epithelium of the anal canal overlying the internal sphincter.They are painful because of their location below the mucocutaneous juncture.Anal ulcers are usually single and occur in the posterior midline or,less commonly ,in the anterior midline.
The fissure triad(emphasis) has been formed:
1.the ulcer itself,
2.the hypertrophic papilla,
3.the sentinel pile.
Two of the most important factors in the genesis of fissures are irritant diarrheal stools and tightenning of the anal canal secondary to nervous tension.
Other factors may be habitual use of cathartics,chronic diarrhea, avulsion of an anal valve,childbirth trauma, laceration by a foreign body,or iatrogenic trauma such as the passage of a large speculum or prostatic massage. Often a cause cannot be definitely identified.
Clinical findings
A.Symptoms :
Rectal pain related to defecation.
Bleeding.
Constipation.
B Signs:
Ulceration of anal canal, hypertrophic papilla,Sentinel pile, Spasm of sphincters,anal tenderness, Stenosis.
C.Special Examinations:
A small-caliber anoscope can be introduced with pressure on the side of the anal canal opposite the lesion.The hypertrophic papilla,ulcer,and associated lesions can then be seen.
Sigmoidoscopic examination should be deferred (but not omitted) until it can be done painlessly.
Differential Diagnosis
Other anal ulcerations that must be differentiated from fissure include the primary lesion of syphilis,anal carcinoma,tuberculous ulceration,and ulceration associated with blood dyscrasias and granulomatous enteritis higher in the intestinal tract.
Treatment
A.Medical Treatment:
1.Treat constipation:diet with high fiber and more water(hydrophilic softening the stools is the mainstay of medical treatment).
2.Ichthammol or hydrocortisone applied in the anal canal with a “pile pipe”.
3.Warm sitz baths after a painful bowel movement.
B.Surgical Treatment:
Lateral internal sphincterotomy, Forceful anal dilation under general anesthesia.
Anorectal Abscess
Essential of Diagnosis:
Persistent throbbing rectal pain.
External evidence of abscess,such as palpable induration and tenderness,may or may not be present.
Systemic evidence of infection.
General considerations
Anorectal abscess results from the invasion of the pararectal spaces by pathogenic microorganisms.
The incidence is much higher in men.The most common cause is infection extending from an anal crypt into one of the pararectal spaces.The others include infection of hair follicles,a complication of deep anal fissure,hemorrhoids,or trauma.
Clinical Findings
1.Persistent throbbing rectal pain.
2.Inspection discloses the characteristic evidence of external swelling,with redness, induration and tenderness.
These signs may not be presented in deeper abscess,but digital rectal examination may reveal the tender swelling.
3.Systemic evidence of infection:fever
Complications
Unless the abscess is evacuated promptly by surgery or ruptures spontaneously,it will extend into other adjacent anotomic spaces.
Treatment
1.Surgical treatment:The treatment of pararectal abscess is prompt incision and adequate drainage.
2.Antibiotics
3.Warm sitz baths and analgesics are palliative.
Anorectal Fistulas
Essential of Diagnosis:
Chronic purulent discharge from a para-anal opening.
Tract that may be palpated or probed leading to rectum.
General Considerations
nBy definition,a fistula must have at least 2 opening connected by a hollow tract---as opposed to a sinus,which is a tract with but one opening.
nMost anorectal fistulas originate in the anal crypts at the anorectal juncture. The crypt becomes injured or infected,the infection extends,and an abscess occurs. When the abscess is opened or when it ruptures, a fistula is formed.
Clinical Findings
A.Symptoms and signs:(emphasis)
1.Chronic (intermittent or constant) purulent discharge from a para-anal opening.
There is usually a history of a recurrent abscess that rupture spontaneously or was surgically drained.
2.A cordlike tract that may be palpated or probed leading to rectum.
B.Special examinations:
Digital rectal examination will frequently reveal a defect at the site of the scarred internal opening.
Proctoscopy ( rectoscopy)
Fistulography may be useful for the complex elusive fistula.
Differential Diagnosis
Hidradenitis suppurativa:a disease of the apocrine sweat glands.
Pilonidal sinus
Granulomatous disease:regional enteritis, Crhon’disease
Infected comedones, infected cysts,chronic folliculitis. and bartholinitis.
Rectal dermoid cysts
Coloperineal fistulas
Sinuses from trauma and foreign bodies.
Complications
Without treatment,chronically infected fistulas may be the source of systemic infection.
Treatment
In most fistulas the only effective treatment is fistulotomy or fistulectomy.
Rectal Cancer
Essentials of diagnosis:
Rectal bleeding.
Alteration in bowel habits.
Sensation of incomplete evacuation.
Intrarectal palpable tumor.
Sigmoidoscopic findings.
Clinical Findings
nA.Symptoms and Signs:
n1.Rectal bleeding:It is the most common symptom,which is the passage of red blood with bowel movements (hematochezia).Blood may or may not be mixed with stool or mucus.
n2.Alteration in bowel habits:alternating constipation and increased frequency of defecation(not true watery diarrhea).
nPhysical examination is important to determine the extent of the local disease,to reveal distant metastasis,and to detect diseases of other organ systems.
nIntrarectal palpable tumor:Distal rectal cancers can be felt as a flat,hard,oval or encircling tumor with rolled edges and a central depression.Its extent,the size of the lumen at the site of the tumor,and the degree of fixation should be noted.
nB.Laboratory Findings:
nCEA(carcinoembryonic antigen)---CEA levels are high in 70% of patients with cancer of the large intestine.But,CEA does not serve as a useful screening procedure,nor is it an accurate diagnostic test for rectal cancer in a curable stage.
CEA is helpful in detecting recurrence after curative surgical resection.
nC.Imageing Studies:
nCT/MRI are helpful in assessing extramural extension in patient with rectal cancer.
n CT,ultrasonography are useful in detecting of liver metastases.
Endorectal ultrasonography is ver y useful in detecting the depth of penetration of rectal cancer.
nD.Special Examinations:
nProctosigmoidoscopy:
nColonoscopy.
nBarium enema.
Treatment
nA.Surgical treatment:
n1.Abdominoperineal resection of the rectum(Miles procedure).
n2.Low anterior resection of the rectum(Dixon procedure).
n3.Local excision.
n4.Palliative procedure (Hartmann procedure):colostomy
nB.Adjuvant therapy
n1.Chemotherapy:adjuvant chemotherapy,new adjuvant chemotherapy.
2.Radiotherapy
3.Other therapy