Day-6 post-colectomy cancer leg swelling on 1-week prophylaxis — Wells-gated duplex, 4-week extension, and provoked-duration counselling

Candidate tasks and model management

Score Wells before touching the ultrasound probe. Her swollen cancer-surgery leg is high pretest probability until shown otherwise — and high probability carries 75% DVT prevalence against 3% for low and 17% for moderate, with only 0.6% events in ruled-out patients at 3 months — so score first, because the score decides whether a negative scan reassures or re-tests.^[1]

Confirm with duplex, and know what the scan can and cannot say. Pooled duplex sensitivity is 94.2% for proximal disease with 93.8% specificity — duplex technique 96.5% sensitive, compression alone 93.8% with 97.8% specificity — so a positive proximal scan treats, while distal sensitivity of 63.5% (56.8% compression alone) means a distal-only question earns surveillance rather than complacency, and repeat scanning yields only 1.3%.^[3]

Extend prophylaxis thinking to 4 weeks — her chart is the error. She sits in the Caprini highest band (malignancy plus major open abdominal surgery), where 30-day VTE reaches 1.94% and over half of all surgical inpatients land — so name her band aloud.^[7] Then fix the stop date: 4 weeks of enoxaparin after abdominal or pelvic cancer surgery gives venographic VTE 4.8% against 12.0% for 1 week (persisting 5.5 versus 13.8% at 3 months) with no bleeding or complication difference — extend, do not stop at day 7.^[8]

Set a provoked-duration plan and counsel PTS by name. Her surgical trigger halves recurrence risk (hazard ratio 0.36) against cancer at 1.72 — so plan duration-limited therapeutic cover with a stop date, unlike unprovoked disease that extends.^[19] Counsel the leg's future explicitly: post-thrombotic syndrome reaches 22.8% at 2 years and 28–29% at 5–8 years, ipsilateral recurrence multiplies PTS risk 6.4-fold, and severity is graded by the Villalta scale — the 1994 disease-specific questionnaire correlating with severity scores and venous filling — so recurrence prevention is PTS prevention, and routine post-DVT stockings earn no prescription.^[19][25]