Presentation on theme: "A. WEISS M.D D.E.S,Chirurgie Générale,Viscérale et Laparoscopique A.F.S/A.F.S.A/DU- France References : R. S.SNELL/ Clinical Anatomy/By SNELL/7e.Vol2."— Presentation transcript:
A. WEISS M.D D.E.S,Chirurgie Générale,Viscérale et Laparoscopique A.F.S/A.F.S.A/DU- France References : R. S.SNELL/ Clinical Anatomy/By SNELL/7e.Vol2. S.I. SCHWARTZ/ Principles of Surgery Companion Handbook/McGraw-Hill/1998. F. C BRUNICARDI and others/Schwartz’s Principles of Surgery/McGraw-Hill/8e/2004. J.SPENCER and others/The Washington Manual of Surgery/Lippincott Williams & Wilkins/5e/2008.
STRUCTURE : 1. RECTUM : The teniae coli end at the distal sigmoid colon, and the longitudinal muscle layer of the rectal wall is continuous. The rectum ( developed from Endoderm ), is 12–15 cm long, extending from the sigmoid colon to the anal canal. The anterior peritoneal reflection is 5–9 cm from the anal verge and usually is larger in males. In its upper part, the rectum is covered with peritoneum anteriorly, and in its lower part, it is extraperitoneal. There are three lateral curves in the rectum that form the valves of Houston. The rectum is surrounded by extensions of the pelvic fascia, which have to be divided during surgical dissection.
ANORECTAL ANATOMY STRUCTURE : 2. ANUS : The pelvic floor is formed by the levator ani muscle. The anal canal ( developed from Ectoderm ), is about 4 cm long, extending from the pelvic floor to the anal verge. The dentate line is the mucocutaneous junction, about 1.5 cm from the anal verge. The anal canal is surrounded by the anal sphincter, which has an internal and external component. The internal sphincter is a continuation of the circular smooth muscle of the rectum, is an involuntary muscle, and is normally contracted at rest. The external sphincter is a voluntary striated muscle and is a caudad extension of the levator ani.
ANORECTAL ANATOMY Arterial Supply : The upper part of the rectum is supplied by the superior rectal artery, which is the terminal branch of the inferior mesenteric artery. The lower part of the rectum is supplied by the middle rectal and inferior rectal arteries, which are branches of the internal iliac arteries. Venous Drainage : This corresponds to the arterial supply, with the upper part of the rectum draining into the inferior mesenteric vein and the lower part into the caval system through the internal iliac veins. The two parts are connected by a rich network of collaterals, and therefore, low rectal and anal canal tumor can metastasize to both the portal and systemic venous systems. Lymphatic Drainage This follows the arterial supply. The upper rectum drains into the inferior mesenteric lymph nodes. The lower rectum may drain into the inferior mesenteric system or the iliac lymph nodes. Below the dentate line the drainage is to the inguinal lymph nodes. Nerve Supply : The sympathetic innervation of the rectum as well as the bladder and the genital system is from the hypogastric nerves originating in the thoracolumbar segments. The parasympathetic supply is from the nervi erigentes (S2–S4 sacral roots). Injury to these nerves during surgical dissection can cause bladder and sexual dysfunction. The sympathetic system usually controls ejaculation, and the parasympathetic controls erection.
HEMORRHOIDS Hemorrhoids are cushions of submucosal tissue containing venules, arterioles, and smooth- muscle fibers that are located in the anal canal. Three hemorrhoidal cushions are found in the left lateral, right anterior, and right posterior positions. Hemorrhoids are thought to function as part of the continence mechanism and aid in complete closure of the anal canal at rest. Because hemorrhoids are a normal part of anorectal anatomy, treatment is only indicated if they become symptomatic. Excessive straining, increased abdominal pressure, and hard stools increase venous engorgement of the hemorrhoidal plexus and cause prolapse of hemorrhoidal tissue. Outlet bleeding, thrombosis, and symptomatic hemorrhoidal prolapse may result
HEMORRHOIDS EXTERNAL HEMORRHOIDS : External hemorrhoids are located distal to the dentate line and are covered with anoderm. Because the anoderm is richly innervated, thrombosis of an external hemorrhoid may cause significant pain. It is for this reason that external hemorrhoids should not be ligated or excised without adequate local anesthetic. A skin tag is redundant fibrotic skin at the anal verge, often persisting as the residual of a thrombosed external hemorrhoid. Skin tags are often confused with symptomatic hemorrhoids. External hemorrhoids and skin tags may cause itching and difficulty with hygiene if they are large. Treatment of external hemorrhoids and skin tags are only indicated for symptomatic relief.
HEMORRHOIDS INTERNAL HEMORRHOIDS : Internal hemorrhoids are located proximal to the dentate line and covered by insensate anorectal mucosa. Internal hemorrhoids may prolapse or bleed, but rarely become painful unless they develop thrombosis and necrosis Internal hemorrhoids are graded according to the extent of prolapse. 1. Bleeding only. 2. Bleeding and prolapse of tissue outside the anus on defecation that reduces spontaneously. 3. Prolapse that requires manual reduction. 4. Irreducible prolapse. Uncomplicated internal hemorrhoids usually do not cause pain. In patients who complain of significant anal pain, other causes have to be looked for (e.g., abscess, fissure, thrombosed external hemorrhoids).
HEMORRHOIDS INTERNAL HEMORRHOIDS, GRADE II, BY RECTOSCOPY.
HEMORRHOIDS TREATEMENT : Medical Therapy : Bleeding from first- and second-degree hemorrhoids often improves with the addition of dietary fiber, ( psyllium derivatives that are hydrophylic are preferable over “dry” fiber ),stool softeners, increased fluid intake, and avoidance of straining. Associated pruritus may often improve with improved hygiene. Non-surgical Therapy : Rubber Band Ligation : Persistent bleeding from first-, second-, and selected third-degree hemorrhoids may be treated by rubber band ligation. Infrared Photocoagulation : Infrared photocoagulation is an effective office treatment for small first- and second-degree hemorrhoids. Sclerotherapy : The injection of bleeding internal hemorrhoids with sclerosing agents is another effective office technique for treatment of first-, second-, and some third-degree hemorrhoids. Excision of Thrombosed External Hemorrhoids : Acutely thrombosed external hemorrhoids generally cause intense pain and a palpable perianal mass during the first 24 to 72 hours after thrombosis. The thrombosis can be effectively treated with an elliptical excision performed in the office under local anesthesia. Because the clot is usually loculated, simple incision and drainage is rarely effective. After 72 hours, the clot begins to resorb, and the pain resolves spontaneously. Excision is unnecessary, but sitz baths and analgesics are often helpful.
HEMORRHOIDS Operative Hemorrhoidectomy : A number of surgical procedures have been described for elective resection of symptomatic hemorrhoids. All are based on decreasing blood flow to the hemorrhoidal plexuses and excising redundant anoderm and mucosa. Closed Submucosal Hemorrhoidectomy. Open Hemorrhoidectomy (Milligan and Morgan hemorrhoidectomy ). Whitehead's Hemorrhoidectomy. Stapled Hemorrhoidectomy. Complications of Hemorrhoidectomy : I. Urinary retention. II. Fecal impaction. III. Bleeding (often in the recovery room). IV. Infection. V. Incontinence. VI. Anal stenosis. VII. Ectropion (Whitehead's deformity).
ANAL FISSURE A fissure in ano is a tear in the anoderm distal to the dentate line. The pathophysiology of anal fissure is thought to be related to trauma from either the passage of hard stool or prolonged diarrhea. A tear in the anoderm causes spasm of the internal anal sphincter, which results in pain, increased tearing, and decreased blood supply to the anoderm. This cycle of pain, spasm, and ischemia contributes to development of a poorly healing wound that becomes a chronic fissure. The vast majority of anal fissures occur in the posterior midline. Ten to 15% occur in the anterior midline. Less than 1% of fissures occur off midline.
ANAL FISSURE Symptoms and Findings : Characteristic symptoms include tearing pain with defecation and hematochezia (usually described as blood on the toilet paper). Patients may also complain of a sensation of intense and painful anal spasm lasting for several hours after a bowel movement. On physical examination, the fissure can often be seen in the anoderm by gently separating the buttocks. Patients are often too tender to tolerate digital rectal examination, anoscopy, or proctoscopy. An acute fissure is a superficial tear of the distal anoderm and almost always heals with medical management. Chronic fissures develop ulceration and heaped-up edges with the white fibers of the internal anal sphincter visible at the base of the ulcer. There is often an associated external skin tag and/or a hypertrophied anal papilla internally. These fissures are more challenging to treat and may require surgery. A lateral location of a chronic anal fissure may be evidence of an underlying disease such as Crohn's disease, human immunodeficiency virus, syphilis, tuberculosis, or leukemia. If the diagnosis is in doubt or there is suspicion of another cause for the perianal pain such as abscess or fistula, an examination under anesthesia may be necessary.
ANAL FISSURE Treatment : Two newly described treatments are aimed at relaxing the internal sphincter: Application of 0.3% topical nitroglycerine cream to the anal canal was reported to induce healing in 60 percent of patients. Intrasphincteric injection of botulinum toxin (Botox) transiently paralyzes the sphincter for 6 months, allowing healing of the fissure. Surgery is indicated in patients who fail conservative treatment and have significant symptoms : It should be used only as a last resort because of the associated risk of anal incontinence, especially in females. The operation is lateral internal sphincterotomy, dividing the distal part of the hypertrophic internal sphincter caudad to the dentate line. It usually is done under local anesthesia on an outpatient basis. The success rate is 90–95 percent.
ABSCESS AND FISTULA Fistulas are the result of abscesses draining to the surface. Most abscesses originate in the anal glands, at the level of the dentate line. From there they may spread to different anatomic locations : I. The intersphincteric plane between the internal and external sphincters. II. The perianal space adjacent to the anus. III. The ischiorectal space between the rectum and the ischial tuberosity. IV. The supralevator space above the levator ani.
The main symptom is severe throbbing anal pain, typically keeping the patient awake at night. The examination reveals swelling and tenderness in the perianal area. If the abscess is intersphincteric, it may be detected only by rectal examination and may not be visible on the outside. The treatment is surgical drainage. Antibiotics are added to patients with extensive infection, have a high fever, or are immunocompromised. An intersphincteric abscess is drained through the anal canal by dividing the overlying mucosa and internal sphincter.
Fifty percent of patients treated by drainage will be cured. The other 50 percent will develop an additional abscess or a perianal fistula connecting the anal canal, usually at the level of the dentate line, to the perianal skin. Treatment of fistula is by fistulotomy, laying the tract open. If the fistula tract incorporates a significant part of the sphincter, fistulotomy may result in incontinence. An alternative treatment may be encircling the involved tissue with heavy silk thread or a rubber band (seton), which provides drainage and stimulates scarring. The seton can be removed later or allowed to gradually cut through the tissue it incorporates while scar formation is progressing, and a gap in the sphincter continuity is avoided.
ABSCESS AND FISTULA Goodsall's rule can be used as a guide in determining the location of the internal opening. In general : Fistulas with an external opening anteriorly connect to the internal opening by a short, radial tract. Fistulas with an external opening posteriorly track in a curvilinear fashion to the posterior midline.
PILONIDAL DISEASE This is a sinus or abscess cavity in the sacrococcygeal area resulting from ingrowth of hair. It is most common in the second and third decades of life, with a male predominance. The primary opening is usually at the intergluteal crease in the midline, about 5 cm above the anus. The acute presentation is that of a painful abscess. After it resolves, a chronically infected and draining sinus remain. Identifying the typical midline pits makes the diagnosis. Surgical treatment includes unroofing and drainage of the sinus, but the primary openings have to be excised to prevent recurrence.