ABCRS key terms

Sharp dissection of the rectum within the avascular mesorectal envelope, removing the rectum and its intact mesorectum down to the pelvic floor. It reduces local recurrence in mid and low rectal cancer and preserves autonomic nerves when performed along embryologic planes.

The shortest distance from tumor to the surgically divided nonperitonealized surface of the rectal specimen. A margin of 1 mm or less predicts local recurrence and is a standard quality metric reported by pathologists.

Dissection of the colon along embryologic fascial planes with central vascular ligation and removal of the intact mesocolon. It aims to harvest more lymph nodes and reduce recurrence in colon cancer, though survival benefit remains debated.

Preoperative chemotherapy plus pelvic radiation given for locally advanced rectal cancer to shrink tumor, improve resectability, and increase sphincter preservation. Response is graded pathologically, and some complete responders may be offered organ-sparing surveillance.

Nonoperative surveillance offered to rectal cancer patients who achieve a clinical complete response after neoadjuvant therapy. It avoids radical surgery and its morbidity but requires strict follow-up because regrowth can occur and salvage surgery may be needed.

A cluster of bowel dysfunction after sphincter-preserving rectal resection, including urgency, frequency, clustering, and incontinence. It results from loss of rectal reservoir, altered innervation, and sphincter injury, and often improves over the first one to two years.

Resection of the rectum with colorectal or coloanal anastomosis for tumors above the sphincter complex. It preserves continence but may cause anastomotic leak or anterior resection syndrome, and a temporary diverting stoma is often used.

Injection of dye or tracer to identify the first draining lymph node(s) for focused pathologic examination. In colon cancer it is used mainly in research settings to detect occult nodal disease; routine use is not standard of care.

An autosomal dominant mismatch repair gene defect causing early-onset right-sided colon cancer, multiple primaries, and extracolonic cancers. Tumors show microsatellite instability, and affected patients require intensive surveillance and consideration of extended colectomy.

An autosomal dominant APC gene mutation causing hundreds to thousands of colorectal adenomas and near-certain cancer by middle age. Prophylactic colectomy with ileorectal anastomosis or proctocolectomy with ileal pouch is standard.

A tumor phenotype caused by deficient DNA mismatch repair, producing length changes in short repeat sequences. It predicts response to immune checkpoint inhibitors and is tested in all colorectal cancers for prognostic and hereditary evaluation.

Restorative proctocolectomy construction in which a folded ileal reservoir is joined to the anal canal after mucosal removal. It is the preferred operation for ulcerative colitis and familial polyposis, with risks of pouchitis and pouch failure.

Inflammation of an ileal pouch causing increased stool frequency, urgency, and bleeding, most common in patients operated for ulcerative colitis. It is diagnosed clinically and endoscopically and usually responds to antibiotics such as ciprofloxacin or metronidazole.

Acute colonic dilation with systemic toxicity complicating severe colitis, defined by nonobstructive dilation of at least 6 cm plus fever, tachycardia, or leukocytosis. It requires intensive medical therapy and urgent colectomy if the patient deteriorates.

Removal of the colon with creation of a terminal ileostomy, used for fulminant colitis, perforation, or refractory disease. In urgent settings it is often done as a subtotal colectomy with rectal stump preservation to allow later reconstruction.

Transmural, skip-lesion granulomatous inflammation that can affect any part of the gastrointestinal tract. Complications include stricture, fistula, and abscess, and surgery is reserved for complications because disease recurs at anastomoses.

Continuous mucosal inflammation beginning in the rectum and extending proximally without skip lesions. It causes bloody diarrhea and is treated medically first; surgery with restorative proctocolectomy is curative but carries pouch-related risks.

Technique of widening a fibrotic intestinal stricture without resection, typically in Crohn disease. It preserves bowel length and is preferred when multiple short strictures exist, provided the segment is not severely inflamed or malignant.

An abnormal tract between the anal canal and perianal skin, often following an infected anal gland. Classification by relation to the sphincter guides treatment, and surgery must balance drainage against incontinence risk.

Surgical laying open of a fistula tract to allow healing by secondary intention. It is effective for simple low fistulas but risks incontinence if the tract crosses significant sphincter muscle, so continence assessment is essential.

Passage of a thread or drain through a fistula tract to maintain drainage and promote fibrosis. It is used for complex or high fistulas, sometimes as a staged first step before definitive repair, and can be cutting or loose.

Suture ligation of the terminal branches of the superior rectal artery, often with mucopexy, for prolapsing hemorrhoids. It is less painful than excision and preserves anoderm, but recurrence may be higher than after conventional hemorrhoidectomy.

Surgical removal of prolapsed hemorrhoidal tissue, usually with ligation of the vascular pedicle. It is effective for grade III and IV hemorrhoids but causes postoperative pain and carries small risks of stenosis and incontinence.

A longitudinal tear in the anoderm, usually posterior midline, causing pain with defecation and bleeding. First-line treatment is stool softening and topical agents that relax sphincter tone; chronic or atypical fissures need further evaluation.

Division of the internal anal sphincter at the lateral position to relieve spasm from chronic anal fissure. It heals most fissures but carries a small risk of incontinence, so it is used cautiously in patients with prior sphincter injury.

Involuntary loss of liquid or solid stool or gas, often from sphincter injury, pudendal neuropathy, or diarrhea. Evaluation includes history, examination, and physiologic testing, with treatment progressing from diet and biofeedback to sphincter repair or neuromodulation.

Implanted electrical stimulation of sacral nerve roots to modulate pelvic floor and bowel function. It treats refractory fecal incontinence and some constipation, typically after a successful temporary test stimulation phase.

Measurement of anal sphincter pressures and rectoanal reflexes using a pressure-sensing catheter. It helps diagnose sphincter weakness, dyssynergic defecation, and Hirschsprung disease, and guides biofeedback therapy.

Pelvic floor training with visual or auditory feedback to improve coordination and strength during defecation or continence. It is first-line for dyssynergic defecation and adjunctive for fecal incontinence, requiring motivated patients and trained therapists.

An abbreviated operation to control hemorrhage and contamination, leaving the abdomen temporarily open for resuscitation and planned reexploration. It is used in severely injured or physiologically deranged patients to avoid lethal triad worsening.

The self-reinforcing combination of hypothermia, acidosis, and coagulopathy that predicts death in severe trauma and hemorrhage. Management prioritizes warming, hemorrhage control, and balanced blood product resuscitation rather than prolonged definitive surgery.

A defect in a surgical bowel connection allowing luminal contents to escape, presenting with sepsis, peritonitis, or abscess. Risk depends on location, blood supply, tension, and patient factors, and treatment ranges from drainage to reoperation.

A multimodal perioperative pathway using evidence-based elements such as carbohydrate loading, opioid-sparing analgesia, early feeding, and early mobilization. It shortens length of stay and reduces complications across colorectal operations.

Intraoperative fluid management titrated to dynamic measures of cardiac output or stroke volume variation rather than fixed volumes. It aims to avoid both hypovolemia and overload, which impair anastomotic healing and prolong ileus.

Intravenous dye imaging used to assess bowel perfusion before constructing an anastomosis. It may reduce leak rates by prompting revision of poorly perfused segments, though evidence for routine benefit is still evolving.

Use of a teleoperated robotic platform to perform colorectal resection with articulated instruments and three-dimensional visualization. Purported advantages include better pelvic dissection ergonomics, but cost and operative time remain concerns.

The process of disclosing a procedure's purpose, risks, benefits, and alternatives so a patient can make a voluntary decision. It requires decision-making capacity and documentation, and is a core ethical and legal obligation before surgery.

A collaborative process in which clinician expertise and patient values are combined to choose among reasonable options. It is especially relevant when treatments have similar survival but different effects on function and quality of life.