Benign Colorectal Disease

A

Rectum

• 1.

  The rectum is 12–15 cm in length and extends from the sacral promontory to the levator ani muscles.

• 2.

  The teniae coli splay out at the rectosigmoid junction and fuse to form a contiguous smooth muscle layer.

• 3.

  The internal rectum is segmented by three horizontal rectal mucosal folds (valves of Houston) that help to support its contents.

• 4.

  The proximal third of the rectum is covered by peritoneum anteriorly and laterally. The anterior peritoneal reflection extends deep into the pelvis to 7 cm above the anal verge and lies behind the bladder in men and behind the uterus (pouch of Douglas) in women.

B

Anal Canal

• 1.

  Anatomic anal canal is 3 cm in length and extends from anal verge to the dentate line.

• 2.

  Surgical anal canal extends from the anal verge to the top of the anorectal ring and is generally 5 cm in length.

• 3.

  The rectum is lined by colonic columnar epithelium. The transitional zone is lined with cuboidal epithelium that lines the anal canal from the columns of Morgagni to the dentate line. Anal glands located in the intersphincteric plane drain into the anal crypts that are pockets formed between each column. Below the dentate line, the anal canal is lined by squamous epithelium.

• 4.

  Internal sphincter (involuntary) is a thickened continuation of the circular smooth muscle of the rectum under control of the autonomic nervous system.

• 5.

  External sphincter (voluntary) is an inferior extension of the puborectalis, which is striated muscle with somatic innervation (branch of the internal pudendal nerve S2–S4).

C

Levator Ani Muscle

• 1.

  Composed of iliococcygeus and pubococcygeus muscles, which constitute the pelvic floor with innervation from the fourth sacral nerve

D

Blood Supply and Lymphatic Drainage

• 1.

  Arterial supply is segmental but with rich anastomoses.

  • a.

    Superior hemorrhoidal—last branch of the inferior mesentery artery

  • b.

    Middle hemorrhoidal—branch of the internal iliac artery

  • c.

    Inferior hemorrhoidal—branch of the internal pudendal artery

• 2.

  Venous drainage parallels the arterial supply.

  • a.

    Superior hemorrhoidal—drains the rectum and upper part of anal canal into the portal system

  • b.

    Middle hemorrhoidal—drains rectum and upper anal canal into internal iliac vein (systemic circulation)

  • c.

    Inferior hemorrhoidal vein—drains rectum and lower anal canal into the systemic venous return

  • d.

    The superior, middle, and inferior hemorrhoidal veins—converge to form the inferior hemorrhoidal plexus in the submucosa of the columns of Morgagni

• 3.

  Lymphatic drainage follows the paths of the arteries.

  • a.

    Superior and middle rectum—drains into the inferior mesenteric artery nodes

  • b.

    Lower rectum and upper anal canal—drain into the superior rectal lymphatics (leading to the inferior mesentery artery) and to the internal iliac nodes

  • c.

    Anal canal distal to the dentate line—has dual drainage to the inguinal nodes and the internal iliac nodes

A

Signs and Symptoms

• 1.

  Rectal bleeding is most common (usually bright red with spotting on toilet paper or squirting into the commode) ± iron deficiency anemia, pruritus, swelling, prolapse, hygiene problems, and pain.

• 2.

  Hemorrhoid prolapse and swelling can cause fecal leakage and skin irritation but not frank incontinence. Clearly document bowel function and anatomy before surgery.

• 3.

  Pain is usually associated with thrombosed external hemorrhoids and subsides in 48–72 hours, although the hemorrhoid will take longer to resolve; internal hemorrhoids can also cause pain if incarcerated or strangulated.

B

Diagnosis

• 1.

  Ensure a thorough examination with visual inspection, digital rectal examination, and anoscopy to develop broad differential, such as perianal Crohn disease, fissure, abscess, condyloma accuminata, rectal/anal neoplasm or polyp, hypertrophied anal papillas, proctitis, or angiodysplasia. Additional endoscopic evaluation may be indicated.

• 2.

  Rectal varices are distinct from hemorrhoids. Present in the setting of portal hypertension or rectal varicosities are more proximal in the anal canal and are best treated with reduction in portal hypertension.

C

Medical Treatment

• 1.

  Medical management is recommended for all hemorrhoids, and grade I–III hemorrhoids often respond.

• 2.

  Recommend dietary modifications including increased fiber (25–30 g/day) and fluid intake (6–8 glasses/day), avoiding constipating foods and foods causing diarrhea. Improve anal hygiene, including sitz baths and avoidance of prolonged straining during defecation. Topical steroids may be used with caution as prolonged use will thin perianal skin. Over-the-counter astringent agents (Tucks, Preparation H) can help mitigate discomfort from external hemorrhoids.

D

Office Treatment

• 1.

  Rubber band ligation is used in the treatment of grade I–III internal hemorrhoids but optimal for grade I–II. Bands must be placed above the dentate line to avoid somatic pain. Depending on provider preference and patient tolerance, typically only one to two hemorrhoids are ligated per session with repeat banding performed at 4 weeks when inflammation has decreased. Band is retained for 2–10 days, while tissue necrosis and scarring occur.

  • a.

    Potential complications (0.5%–8% rate) include vasovagal reaction, severe bleeding after necrotic tissue sloughs off (1–2 weeks postoperatively), and pelvic sepsis (presenting with pelvic pain, fever, urinary incontinence, and perineal cellulitis).

• 2.

  Sclerotherapy involves injection of hemorrhoid or its base with sclerosing agent, which obliterates the hemorrhoid by thrombosis then fibrosis. This is the preferred treatment for patients who are on anticoagulation or are immunocompromised.

• 3.

  Infrared coagulation involves direct application of infrared light resulting in protein destruction. It is most applicable to grades I and II hemorrhoids without prolapse or thick tissue and requires 2–3 repeat treatments at 2-week intervals.

• 4.

  Other therapies include cryotherapy, bipolar diathermy, and direct current therapy.

E

Surgical Hemorrhoidectomy

Indicated for large grade III–IV internal hemorrhoids, mixed hemorrhoids, large external hemorrhoids, and patients who failed office procedural management

• 1.

  Closed or Ferguson hemorrhoidectomy is most commonly performed for complex/mixed hemorrhoids.

  • a.

    A perianal nerve block is performed by injecting four quadrants around the anus in both superficial submucosa and deep intersphincteric spaces.

  • b.

    The hemorrhoidal bundle is retracted with forceps or hemostat, and the anoderm is excised with an elliptical incision.

  • c.

    The hemorrhoid is then dissected off the external and internal sphincter, sparing muscle, and excised to the proximal anal canal, while leaving enough anoderm for closure without narrowing the anal canal.

  • d.

    If not excised with cautery and hemostatic, the pedicle is suture ligated with a chromic or Vicryl suture followed by approximation of wound edges with a running chromic suture beginning at the apex (using this as a lever) and extending to the anoderm. Up to three hemorrhoidal bundles may be excised in this fashion, permitting enough anoderm remains to prevent the complication of anal stenosis.

• 2.

  Procedure for prolapsing hemorrhoids (PPH) is best for patients with large internal hemorrhoids with minimal external component.

  • a.

    Circumferential stapled hemorrhoidectomy (or more accurately hemorrhoidopexy) involves transanal circular stapling of redundant anorectal mucosa with a specialized circular stapling instrument. Redundant mucosa is drawn into the instrument with a circumferential purse-string suture and excised within the device. Care is taken to ensure this is performed well above the dentate line to avoid somatically innervated anoderm and to avoid injury to vaginal canal that may lead to the dreaded complication of a rectovaginal fistula.

  • b.

    Patients often have less postoperative pain and shorter recovery, but there is a higher rate of recurrence.

• 3.

  Hemorrhoidal artery ligation (HAL) is a new technique that uses a Doppler transducer to localize the proximal feeding vessels above the dentate line. Often six arteries are located and ligated with 2-0 braided suture.

• 4.

  Thrombosed external hemorrhoids: These can be extremely painful and should be excised if seen within 48 hours. Beyond this time, texts recommend conservative therapy with analgesics, and sitz baths are appropriate, but clinically if the pain is unrelenting, surgical excision can be offered.

A

Overview

• 1.

  Represents an acute or chronic linear tear in the skin or anoderm distal to the dentate line. Most are located at posterior midline, but 10% are anterior especially in women. Lateral or multiple fissures should raise suspicion of trauma, inflammatory bowel disease, lymphoma, neoplasm, or infection and require further investigation with biopsy and/or endoscopic evaluation.

• 2.

  There is equal incidence among men and women, and most are in young adults.

• 3.

  Proposed etiology is increased resting anal pressure and hypertonia of internal anal sphincter.

B

Signs and Symptoms

• 1.

  These include sharp tearing pain associated with defecation and possible bright red blood on toilet paper.

• 2.

  Chronic fissures may be associated with a “sentinel pile” or hypertrophied papilla and external anal skin tag.

C

Treatment

• 1.

  Nonoperative management is initial treatment and best for acute fissures.

  • a.

    Stool softeners and bulk laxatives relieve straining.

  • b.

    Sitz baths offer symptomatic relief and improve hygiene.

  • c.

    Topical application of compounded calcium channel blockers (nifedipine, diltiazem) has been proven to be the most effective and least symptomatic medical therapy and will achieve healing in 75%–80% of patients who comply with fiber supplementation.

  • d.

    Anesthetic suppositories and nitroglycerin 0.2% cream may be helpful but may cause headache and are associated with increased cost when compared with compounded calcium channel blockers.

  • e.

    Chemical sphincterotomy is achieved with botulinum toxin administered into the internal anal sphincter.

• 2.

  Operative therapy is indicated for unsuccessful response to above management. The goal of surgery is to achieve relaxation of internal anal sphincter.

  • a.

    Lateral internal sphincterotomy is the surgical treatment of choice, often performed on right side to avoid left lateral hemorrhoid.

  • b.

    Fissurectomy with advancement flap is an option for patients without hypertonia of internal anal sphincter or with compromised fecal incontinence.

A