Distal DVT (isolated calf vein)
Encounter flow
10/12 authoredCanonical 12-phase frame with authored status for this dossier.
Frame
Distal (isolated calf) DVT — anticoagulation vs serial US surveillance is the central decision; lower extension/PE risk than proximal DVT but extension occurs in ~15% within 2 weeks
distal location confirmed
Patient inputs (7)
Older patients higher recurrence + extension risk → favors AC over surveillance
Severe symptoms favor AC for symptom relief; mild symptoms allow surveillance
Whole-leg US confirms isolated distal location; serial US for surveillance strategy (Righini JTH 2009 PMID 38546285)
HAS-BLED determines tolerability of AC vs surveillance
Extension risk factors: positive D-dimer, extensive thrombus burden, persistent provoking factor, prior DVT, active cancer, hospitalization (ACCP 2021)
eGFR for DOAC dosing if AC chosen
Persistently elevated D-dimer is risk factor for extension → favors AC (CACTUS PMID 27836513 subgroup analyses)
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Severity triggers (5)
- informationallife_threateningmajor_bleed_on_iddvt_ACMajor bleed on AC for IDDVT (Hgb drop ≥2, transfusion, ICH, retroperitoneal) — particularly concerning given lower benefit threshold for IDDVTTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereextension_distal_to_poplitealExtension of distal DVT to popliteal vein on serial US (during surveillance pathway or despite AC)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalseverefailed_surveillance_with_extensionPatient on surveillance pathway returns with worsening symptoms or extension on repeat USTrigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderatepersistent_d_dimer_elevation_post_treatmentD-dimer remains elevated 1 month after completing AC for IDDVT — suggests ongoing thrombotic activityTrigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderateiddvt_in_active_cancerIDDVT discovered in patient with active cancer — favors AC over surveillance regardless of symptoms (persistent provoking factor)Trigger could not be auto-evaluated — needs clinician judgement.
Workflow calculators
Run this disease's risk and dosing calculators inline.
Recommended regimen
Isolated distal DVT — AC vs surveillance decision (ACCP 2021)- apixabanfirst linedoac_factor_xa_direct10 mg BID × 7 d → 5 mg BID • PO • BID × 6-12 weekstriggers: iddvt_high_extension_risk, severe_symptoms, persistent_provoking_factor, no_active_bleedAMPLIFY (PMID 23808982) for full-dose efficacy; ACCP 2021 supports DOAC for IDDVT requiring ACrxcui 1364430
- rivaroxabanfirst linedoac_factor_xa_direct15 mg BID × 21 d → 20 mg daily • PO • BID then daily × 6-12 weekstriggers: iddvt_high_extension_risk, no_active_bleed, egfr_above_30EINSTEIN-DVT PMID 21128814 — non-inferior to standard carerxcui 1114195
- enoxaparincomorbidity specificlmwh1 mg/kg SC BID • SC • BIDtriggers: pregnancy, active_cancer_doac_unsafe, severe_renal_impairmentLMWH preferred in pregnancy and select cancer-VTE per CARAVAGGIO PMID 32223112rxcui 67108
outpatient playbook — drug actions (1)
- 1. no AC if completed treatmentn/a • n/a • n/atrigger: Completed 6-12 weeks AC for provoked IDDVTACCP 2021 Class 2B — extended AC not routinely indicated for IDDVT
Auto-drafted A&P note
outpatientSubjective
- Possible entry pathways: Isolated calf pain, swelling, tenderness without thigh involvement → suggests distal DVT; Compression US shows non-compressible distal vein (peroneal, posterior tibial, soleal) with patent popliteal/femoral → isolated distal DVT (IDDVT); Whole-leg compression US identifies isolated distal DVT not detected by proximal-only protocol (Bernardi 2008).
Objective
- No vitals, labs, or imaging entered for this encounter.
Assessment
**Distal DVT (isolated calf vein)** (cardio.dvt.distal.v1). Scope: Distal (isolated calf) DVT — anticoagulation vs serial US surveillance is the central decision; lower extension/PE risk than proximal DVT but extension occurs in ~15% within 2 weeks No severity triggers fired against current inputs.
Plan
Regimen axis: **Isolated distal DVT — AC vs surveillance decision (ACCP 2021)**. 1. apixaban 10 mg BID × 7 d → 5 mg BID PO BID × 6-12 weeks (doac_factor_xa_direct, first line) — AMPLIFY (PMID 23808982) for full-dose efficacy; ACCP 2021 supports DOAC for IDDVT requiring AC 2. rivaroxaban 15 mg BID × 21 d → 20 mg daily PO BID then daily × 6-12 weeks (doac_factor_xa_direct, first line) — EINSTEIN-DVT PMID 21128814 — non-inferior to standard care 3. enoxaparin 1 mg/kg SC BID SC BID (lmwh, comorbidity specific) — LMWH preferred in pregnancy and select cancer-VTE per CARAVAGGIO PMID 32223112 Setting playbook (outpatient) — Long-term IDDVT survivors (rarely require chronic AC); surveillance for recurrence; PTS surveillance (low rate vs proximal DVT) 4. no AC if completed treatment n/a n/a n/a — Completed 6-12 weeks AC for provoked IDDVT (ACCP 2021 Class 2B — extended AC not routinely indicated for IDDVT) Non-pharmacologic actions: - VTE risk reduction lifestyle (mobility, weight, hormones) - Patient education on recurrence symptoms AVOID / contraindication checks: - Doac_avoid_active_bleeding (FDA labels) - Apixaban_avoid_egfr_below_15 (FDA label) - Warfarin_avoid_pregnancy_use_lmwh (ASH 2018) - Decision:surveillance_only_low_extension_risk (ACCP 2021 Class 2C — CACTUS PMID 27836513 showed no benefit nadroparin in low risk IDDVT)
Monitoring
Regimen monitoring: - serial compression us d5-7 and d10-14 if surveillance (ACCP 2021) - cbc q week x first 4 weeks if AC (ASH 2020) - creatinine at baseline and q3mo if AC (FDA labels) - symptom review for extension or pe at each visit Setting (outpatient) monitoring: - Annual reassessment Follow-up plan: AC pathway: stop at 6-12 weeks if provoked + transient risk; consider extended only if extension or unprovoked + high recurrence risk. Surveillance pathway: convert to proximal pathway if extension - Close-out criterion: final disposition documented Monitoring phase: AC pathway: bleed surveillance, weekly CBC × 4 weeks. Surveillance pathway: repeat US days 5-7 + 10-14 + symptoms
Disposition
Current setting: outpatient — Long-term IDDVT survivors (rarely require chronic AC); surveillance for recurrence; PTS surveillance (low rate vs proximal DVT) Disposition criteria: - Long-term annual surveillance Escalation triggers (move to higher acuity): - Recurrent VTE → re-evaluate per parent dossier - New cancer dx → cancer-VTE evaluation
Earlier-Return Triggers
Return-precaution thresholds (watch for): - [LIFE_THREATENING] Major bleed on AC for IDDVT (Hgb drop ≥2, transfusion, ICH, retroperitoneal) — particularly concerning given lower benefit threshold for IDDVT - [SEVERE] Extension of distal DVT to popliteal vein on serial US (during surveillance pathway or despite AC) - [SEVERE] Patient on surveillance pathway returns with worsening symptoms or extension on repeat US
Citations
- ACCP/CHEST 2021 Antithrombotic + ASH 2020 VTE Treatment [PMID:34352278](https://pubmed.ncbi.nlm.nih.gov/34352278/) - Cited evidence (PMID 33007077) [PMID:33007077](https://pubmed.ncbi.nlm.nih.gov/33007077/) - Cited evidence (PMID 27836513) [PMID:27836513](https://pubmed.ncbi.nlm.nih.gov/27836513/) - Cited evidence (PMID 38546285) [PMID:38546285](https://pubmed.ncbi.nlm.nih.gov/38546285/) - Cited evidence (PMID 18840838) [PMID:18840838](https://pubmed.ncbi.nlm.nih.gov/18840838/) Last reconciled with current guidelines: 2026-05-14.
- ACCP/CHEST 2021 Antithrombotic + ASH 2020 VTE Treatment — PMID:34352278
- Cited evidence (PMID 33007077) — PMID:33007077
- Cited evidence (PMID 27836513) — PMID:27836513
- Cited evidence (PMID 38546285) — PMID:38546285
- Cited evidence (PMID 18840838) — PMID:18840838