Assoc. Prof.Cengiz Dibekoğlu, MD

General Surgeon

Laparoscopic · Robotic · Oncologic Surgery

Conditions/Rectal Cancer/Chapter

Detailed chapter

Ultra-Low Anterior / Intersphincteric Resection

Sphincter-preserving effort for very distal tumors — partial internal sphincter resection with coloanal anastomosis when external sphincter can still be saved oncologically.

Ultra-low anterior resection and intersphincteric resection (ISR) are used for selected very distal rectal tumors when classic LAR cannot take an adequate distal margin, yet the external sphincter can still be preserved oncologically. Part of the internal sphincter may be resected; the anastomosis is usually coloanal. The aim is organ preservation instead of Miles — functional outcomes are more delicate.

Ultra-low / intersphincteric resection · educational illustration · English labels below

Related educational figures

Tap a figure to enlarge.

  • TME plane

Who may be a candidate?

  • Very distal (low) rectal tumors
  • No external sphincter invasion; R0 appears achievable with ISR
  • Patients downstaged after neoadjuvant / TNT toward sphincter preservation
  • Informed patients accepting functional risk instead of permanent stoma

Possible advantages

  • Potential organ and sphincter preservation instead of permanent colostomy
  • Oncologic clearance still pursues intact TME plus adequate distal margin
  • Neoadjuvant shrinkage can improve ISR candidacy in selected cases
  • Protective ileostomy is nearly always used to shelter the coloanal join

Limits & realistic expectations

  • External sphincter or levator invasion generally needs Miles (APR)
  • Poor baseline continence may worsen quality of life after ISR
  • Difficulty adhering to follow-up and rehabilitation is a relative contraindication
  • Organ preservation can bring urgency, frequency, and leakage trade-offs

Step-by-step overview

  1. 1

    Abdominal TME phase

    Standard TME mobilises the mesorectum in the pelvis; vascular pedicle and nerve-sparing principles match LAR.

  2. 2

    Perineal / intersphincteric phase

    Via an anal approach the intersphincteric groove is identified. Internal sphincter is resected as needed; external sphincter is preserved.

  3. 3

    Specimen integrity

    Abdominal and perineal dissections meet; tumor, mesorectum, and distal margin come out as one specimen.

  4. 4

    Coloanal anastomosis

    Colon is brought to the anal canal and joined (hand-sewn or stapler-assisted). Perfusion and tension are critical; colonic J-pouch or coloplasty may be considered (centre preference).

  5. 5

    Protective ileostomy

    Temporary ileostomy is almost always added. Closure is planned after anastomotic healing.

Key points

  • Intersphincteric plane
    Tap for details

    Dissection descends between internal and external sphincter so the tumor can be cleared while aiming to leave the external sphincter.

  • Coloanal anastomosis
    Tap for details

    Colon is joined at anal-canal level. Protective ileostomy is required in most cases.

  • Function trade-off
    Tap for details · key note inside

    Organ preservation may come with frequent stools, urgency, and leakage risk. Some patients accept that risk; others prefer Miles after shared decision-making.

  • Role of neoadjuvant therapy
    Tap for details

    Downsizing can improve ISR margins. Decision still rests on MRI, examination, and tumor board — not every distal tumor is an ISR.

  • After surgery
    Tap for details

    Intensive stoma teaching and early clinic adherence; pelvic-floor rehab and diet adjustment; close watch for leak or pelvic sepsis; long-term continence scoring; LARS management after stoma closure.

  • Important
    Tap for details · key note inside

    Educational information only — ultra-low / ISR candidacy is MRI- and examination-driven and must be individualized.

Frequently asked questions

  • Is this always better than Miles?
    Tap for details

    In well-selected oncologically suitable patients it offers organ preservation; function is not ‘better than Miles’ for everyone. The decision is personal after counselling.

  • Is there still a permanent stoma risk?
    Tap for details

    The goal is temporary diversion. Severe leak, poor function, or recurrence / salvage surgery can lead to a permanent stoma.

  • Does removing internal sphincter affect continence?
    Tap for details

    Yes. More internal sphincter resected can increase urgency, night soiling, and leakage. Baseline sphincter function is assessed carefully before surgery.

  • Is a protective ileostomy mandatory?
    Tap for details

    It is usually recommended for very low coloanal anastomoses. It does not abolish leak risk but can lessen clinical impact. Final choice follows anastomotic and patient risk.

  • When does rehabilitation start?
    Tap for details

    Pelvic-floor training and diet advice can begin before stoma closure; after continuity is restored, close follow-up and personalised exercises continue.

More chapters in this hub

Appointment / info

+90 542 725 50 70WhatsAppTumor boardBack to hub →Full Turkish chapter →

Educational information only; not a substitute for clinical evaluation.

Medical editor: Assoc. Prof. Cengiz Dibekoğlu, MD · Last medically reviewed: August 2026 · English patient-education chapter.

AppointmentWhatsAppMessageTumor boardRequest