Anorectal: Proctectomy

Basics

• Resection of Sigmoid, Rectum & Anus
  • Loss of Internal Anal Sphincter
• Requires a Permanent Colostomy
• Splenic Flexure Mobilization Not Required

Abdominal Dissection

• Mobilize the Sigmoid & Left Colon
  • Pack & Retract Small Bowel to the Right with a Moist Lap Pad
  • Retract Sigmoid Medially
  • Dissect Sigmoid Lateral-to-Medial Along the White Line of Toldt
  • Continue Dissection in This Plane Bringing the Left Colon Away from Gerota’s Fascia
    • Care to Preserve Gonadal Vessels & Left Ureter
• Enter the Retrorectal Avascular Plane at the Base of the Sigmoid Mesocolon
• Identify & Ligate the Inferior Mesenteric Vessels
  • Retract Sigmoid to the Right
  • Identify & Divide IMA 1-2 cm From the Aortic Origin
  • Identify & Divide IMV at the Ligament of Treitz – Allows Full Mobilization of the Splenic Flexure
• Sharply Dissect Circumferentially Around the Mesorectum
  • Retract Sigmoid Anteriorly
  • Start Dissection Posterior & Then Move Lateral
    • Avoid Injury to the Superior & Inferior Hypogastric Plexuses
    • Avoid Injury to the Lateral Hypogastric & Pelvic Parasympathetic Nerves
  • Finish Dissection Anteriorly Along Denovilliers’ Fascia
  • *Blunt Dissection Associated with Higher Recurrence
• Divide the Sigmoid Colon
  • Divide Sigmoid Mesentery to the Bowel Wall
  • Staple Division of the Sigmoid Colon
• Dissect as Far into Pelvis as Possible Including Wide Mesenteric Excision (WME)
• Create End Colostomy
  • Typically Done After Perineal Dissection if in Lithotomy Position
  • Can Be Done Before if Positioning Prone for Perineal Dissection

Perineal Dissection

• Approach:
  • Traditional/Standard Resection – “Waist” Resection
    • “Coned In” Sparing the Levators
  • Extended/Extralevator (ELAPE) – “Cylinder” Resection
    • “Cylindrical” with Wide Resection of Levators
    • Preferred if Tumor Invades External Sphincter or Levators
    • Some Argue Lower Rates of Positive Margins Although Literature Shows No Improved Outcomes
    • Higher Rates of Wound Complications
• Close Anus with Purse-String Suture
• Wide Vertical Elliptical Incision Around the Anus
• Dissect into the Ischiorectal Space
  • Start Posteriorly Over the Coccyx
    • Divide the Anococcygeal Raphe
    • Divide Waldeyer’s Fascia & Enter the Presacral Space
    • Divide Superficial Fascia Laterally
    • Continue Posterior Dissection While Elevating the Rectum
  • Identify & Divide the Lateral Levator Muscles
    • Insert Finger into Presacral Space & Sweep Laterally
    • Divide Levator Muscles Bilaterally
  • Finish Dissection Anteriorly
    • Retract Rectum Inferiorly & Posteriorly
    • Avoid Injury to Urethra or Vaginal Wall from Dissecting Too Anteriorly
    • Once Able, The Sigmoid is Delivered Through the Posterior End & with Traction the Final Levator Attachments & Transected
• Remove Specimen Through the Pelvic Ring
• Close Perineum in Multiple Layers with Vertical Mattress on the Skin
  • Consider Rotational Pedicle Flap if Received Neoadjuvant Radiation – Often Use Rectus Abdominis Muscle Flap (Large & Avoids Radiated Skin)

Complications

• Perineal Wound Complications
  • Common (36-80%)
  • Risk Factors: Prior XRT, Malnutrition, Smoking & Obesity
• Autonomic Nerve Injury
  • Sympathetic Nerves
    • Sx: Increased Bladder Tone, Reduced Capacity & Impaired Ejaculation
  • Parasympathetic System
    • Sx: Voiding Difficulty, Erectile Dysfunction & Decreased Vaginal Lubrication
• Bleeding/Hematoma (0-4%)