UKOM Sp.DVE cheat sheet

Arterial wall layers: intima (endothelium, internal elastic lamina), media (smooth muscle, elastin), adventitia (collagen, vasa vasorum); atherosclerosis is an intimal disease, medial degeneration causes aneurysmal dilatation.

Poiseuille relationship: flow ∝ ΔP·r⁴/(8ηL); halving radius cuts flow 16-fold, so small diameter changes dominate resistance.

Aortic branches in order: coronary, brachiocephalic (→right subclavian, right common carotid), left common carotid, left subclavian; ligamentum arteriosum marks the isthmus.

Femoral bifurcation anatomy: common femoral gives superficial femoral and profunda femoris; profunda collaterals sustain limb viability in SFA occlusion.

Popliteal artery is the most commonly injured peripheral artery in trauma and the most common site of peripheral aneurysm.

Virchow triad: stasis, endothelial injury, hypercoagulability - the mechanistic basis of venous thrombosis and of access-graft thrombosis.

Starling forces govern interstitial fluid: net filtration = capillary pressure + interstitial oncotic pressure − plasma oncotic pressure − interstitial pressure; lymphatic drainage returns excess.

Endothelial nitric oxide mediates flow-mediated vasodilatation; loss of NO bioactivity precedes structural atherosclerosis and is reversed by exercise and statins.

ABPI ≤0.90 has high sensitivity/specificity for PAD; 0.50-0.90 mild-moderate, <0.50 severe; >1.30 suggests medial calcinosis (diabetes, CKD) and requires toe-brachial index or waveform analysis.

Exercise ABPI: a fall of >20% or >30 mmHg after treadmill testing confirms haemodynamically significant disease when resting indices are normal.

Continuous-wave Doppler waveform: triphasic is normal; biphasic is intermediate; monophasic indicates proximal stenosis; absence of flow indicates occlusion.

Duplex criteria for ICA stenosis: peak systolic velocity >125 cm/s suggests ≥50%; >230-250 cm/s with end-diastolic velocity >100 cm/s suggests ≥70%; ratio to common carotid velocity (≥3.2-4.0) improves accuracy.

Toe-brachial index normal ≥0.70; toe pressures <30-50 mmHg predict poor healing of forefoot ulcers and amputation wounds.

Transcutaneous oximetry <30 mmHg indicates poor wound healing; 30-40 mmHg is borderline; >40 mmHg predicts healing.

Ankle-brachial index must be measured with the patient supine and appropriately sized cuff; falsely low readings occur with cuff size mismatch and vessel compression.

Vein mapping before bypass: great saphenous vein diameter ≥3 mm and absence of sclerosis/varicosity predicts suitability as conduit.

Rutherford classification: category 0 asymptomatic; 1-3 claudication (mild/moderate/severe); 4 rest pain; 5 minor tissue loss; 6 major tissue loss. Fontaine: I asymptomatic, IIa/IIb claudication, III rest pain, IV ulceration/gangrene.

Supervised exercise therapy and smoking cessation are first-line for claudication; cilostazol improves walking distance but is contraindicated in heart failure.

Indications for revascularisation: disabling lifestyle-limiting claudication after failed conservative therapy, rest pain, tissue loss, or acute limb-threatening ischaemia.

TASC II/TransAtlantic classification guides aortoiliac choice: focal common iliac lesions favour endovascular stenting; extensive bilateral aortoiliac disease favours aortobifemoral bypass.

Aortobifemoral bypass patency ~85-90% at 5 years; extra-anatomic axillobifemoral grafts have lower patency (~60-70% at 5 years) but lower physiological insult.

Infrainguinal bypass conduit: autologous great saphenous vein is superior to prosthetic; below-knee popliteal and tibial targets should use vein whenever available.

Critical limb-threatening ischaemia: rest pain >2 weeks, ulceration or gangrene with ABPI <0.4 or toe pressure <30 mmHg; 1-year amputation risk is high without revascularisation.

Antiplatelet therapy (aspirin or clopidogrel) reduces major adverse cardiovascular events in PAD; dual antiplatelet therapy is indicated after endovascular stenting for a defined period.

Elective AAA repair threshold: diameter ≥5.5 cm in men, ≥5.0 cm in women, or rapid growth >1 cm/year, or symptomatic aneurysm.

Ruptured AAA triad: abdominal/flank pain, hypotension, pulsatile mass; permissive hypotension (systolic ~90 mmHg) until haemorrhage control improves survival.

EVAR vs open repair: EVAR has lower 30-day mortality and morbidity but higher reintervention and late rupture rates; long-term survival converges.

Type A dissection (ascending aorta involved) is a surgical emergency; type B dissection (descending only) is managed medically unless complicated by malperfusion, rupture, or rapid expansion.

Stanford type A = any ascending involvement; Stanford type B = descending only. DeBakey I = ascending + descending, II = ascending only, III = descending only.

Aortic dissection management: heart rate control (beta-blocker, target ~60 bpm) and blood pressure control reduce shear stress (dP/dt); analgesia is essential.

Thoracoabdominal aortic aneurysm repair: spinal cord ischaemia risk increases with extent (Crawford II highest); CSF drainage and distal perfusion reduce paraplegia risk.

Mycotic aneurysm: consider Salmonella in the aorta; treatment is resection with debridement plus extra-anatomic or in-situ reconstruction with antimicrobial therapy.

CEAP classification: C clinical (C0-C6), E etiology (congenital/primary/secondary), A anatomy (superficial/deep/perforator), P pathophysiology (reflux/obstruction/both).

Venous duplex: reflux defined as valve closure time >0.5 s in superficial veins and >1.0 s in deep veins; perforator reflux >0.35 s.

Venous ulcer healing: compression therapy is the mainstay; ABPI must be >0.8 before applying high compression; multilayer bandages or compression stockings 30-40 mmHg.

Endovenous thermal ablation (laser or radiofrequency) or ultrasound-guided foam sclerotherapy is preferred over open stripping for great saphenous incompetence.

DVT diagnosis: Wells score plus D-dimer; D-dimer is highly sensitive but poorly specific, and should not be used alone to rule out DVT in high-probability patients.

Provoked vs unprovoked DVT determines anticoagulation duration: 3 months for provoked, at least 3-6 months for unprovoked, and indefinite for recurrent or active cancer-associated thrombosis.

Post-thrombotic syndrome: chronic pain, swelling, hyperpigmentation, ulceration after DVT; elastic compression stockings reduce incidence and severity.

Lymphedema: protein-rich interstitial fluid accumulation; treatment is complex decongestive therapy (manual lymphatic drainage, compression, exercise, skin care), not diuretics.

Hard signs of arterial injury: pulsatile bleeding, expanding haematoma, absent distal pulses, bruit/thrill, distal ischaemia - immediate exploration or angiography.

Soft signs: small stable haematoma, unexplained hypotension, proximity injury, nerve deficit - investigate with CT angiography or duplex.

Acute limb ischaemia: 6 Ps - pain, pallor, pulselessness, paraesthesia, paralysis, poikilothermia.

Rutherford acute limb ischaemia classes: I viable (no sensory/motor deficit, audible Doppler signals); IIa marginally threatened (minimal sensory loss, no motor deficit, inaudible arterial but audible venous signals); IIb immediately threatened (rest pain, sensory loss, motor deficit); III irreversible (rigidity, anaesthesia, no Doppler signals).

Class I and IIa: urgent revascularisation (embolectomy, thrombolysis, or bypass) within hours; class IIb: immediate surgery; class III: primary amputation.

Embolism vs thrombosis: embolism has sudden onset, known source (AF, endocarditis), normal contralateral pulses, and no collaterals; thrombosis has progressive onset, diffuse disease, and collaterals.

Compartment syndrome: pain out of proportion, pain on passive stretch; fasciotomy is indicated urgently; delay causes myonecrosis and nerve injury.

Post-reperfusion injury: hyperkalaemia, acidosis, myoglobinuria, arrhythmia; monitor potassium, renal function, and urine output after revascularisation.

Fistula-first policy: autologous arteriovenous fistula (AVF) is preferred over AV graft (AVG) and catheter; AVF has lower infection and thrombosis rates and better long-term patency.

Rule of 6s for AVF maturity: flow ≥600 mL/min, diameter ≥6 mm, depth ≤6 mm, at least 6 weeks after creation.

Radiocephalic (Brescia-Cimino) fistula is first choice at the wrist; brachiocephalic at the elbow; brachiobasilic transposition when cephalic vein is inadequate.

AVG should be considered when native veins are inadequate; PTFE grafts have 1-year primary patency ~50-60% and higher infection risk than AVF.

Catheter-related bloodstream infection: remove tunnelled catheter when possible, culture, and treat with systemic antibiotics; Staphylococcus aureus is the most common organism.

Steal syndrome: distal hypoperfusion after access creation; treat with banding, DRIL (distal revascularisation-interval ligation), or proximalisation of inflow.

Access surveillance: monitor flow (Qa), static pressures, and recirculation; declining flow predicts stenosis; treat stenosis with angioplasty when flow <500 mL/min or pressure abnormalities.

Central venous stenosis is common in patients with prior catheters; treat with angioplasty ± stent when causing symptomatic arm swelling or access dysfunction.

Seldinger technique: needle puncture, guidewire insertion, needle removal, catheter/sheath over wire; confirm wire position before dilation.

Contrast nephropathy prevention: hydration with isotonic saline, limit contrast volume, use low-osmolar contrast; N-acetylcysteine evidence is weak.

Radiation safety: ALARA principle; use pulsed fluoroscopy, last-image hold, collimation, and minimise magnification; wear lead apron (≥0.35 mm Pb) and dosimeter.

Deterministic radiation injury threshold ~2 Gy for skin erythema; fluoroscopic dose monitoring and recording are mandatory in prolonged procedures.

Balloon angioplasty works by plaque fracture and vessel stretch; dissection and elastic recoil are failure modes; bailout stenting for flow-limiting dissection.

Drug-coated balloons and drug-eluting stents reduce restenosis in femoropopliteal disease; stent fractures are more common in the popliteal segment, favouring interwoven or nitinol stents.

Carbon dioxide angiography is an alternative in renal impairment and contrast allergy; it is less useful in small vessels and below the knee.

Anticoagulation during angiography: unfractionated heparin (typically 50-100 units/kg) to maintain ACT >250 s during prolonged intervention.

Bypass principles: inflow and outflow must be adequate; avoid tension, kinking, and torsion; mark orientation; use systemic heparin before clamping.

Endarterectomy: open (longitudinal arteriotomy with patch) or eversion technique; patch angioplasty reduces restenosis after carotid endarterectomy.

Carotid endarterectomy: indicated for symptomatic ≥70% stenosis (benefit greatest), 50-69% (moderate benefit); timing within 2 weeks of symptoms improves outcomes.

Perioperative beta-blockade in vascular surgery reduces cardiac events but increases risk of hypotension and stroke; use judiciously in high-risk patients already on beta-blockers.

Perioperative anticoagulation reversal: protamine reverses heparin (1 mg per 100 units); fresh frozen plasma or vitamin K for warfarin; idarucizumab for dabigatran.

Postoperative monitoring after aortic surgery: watch for bleeding, ischaemia (bowel, limb, spinal cord), renal failure, and graft infection.

Anaesthesia choice: regional vs general anaesthesia for carotid endarterectomy and lower limb bypass - outcomes largely equivalent; patient factors guide choice.

Surgical site infection prevention: antibiotic prophylaxis within 60 minutes of incision, glycaemic control, normothermia, and avoidance of shaving (use clippers).

Statin therapy is indicated for all patients with PAD regardless of LDL, targeting ≥50% LDL reduction; high-intensity statin improves walking distance and reduces cardiovascular events.

Smoking cessation is the single most effective intervention in PAD; nicotine replacement, varenicline, and behavioural support should be offered.

Antiplatelet therapy: aspirin 75-100 mg or clopidogrel 75 mg for secondary prevention in PAD; clopidogrel is preferred in patients with aspirin intolerance and after stenting.

Dual antiplatelet therapy is used for a limited period after endovascular stenting (often 1-3 months) or carotid stenting (typically 1 month), then single agent.

Anticoagulation for VTE: DOACs (apixaban, rivaroxaban) are first-line for most patients; warfarin remains for antiphospholipid syndrome and mechanical valves.

Heparin-induced thrombocytopenia: platelet drop >50% or thrombosis 5-10 days after heparin; stop heparin, start argatroban or bivalirudin, avoid platelet transfusions.

Hypertension and diabetes control reduce cardiovascular events; target BP <140/90 mmHg generally, with individualised targets in CKD and diabetes.

Peripheral arterial disease is a coronary risk equivalent; risk factor modification should be as aggressive as in established coronary disease.

Informed consent requires capacity, disclosure of material risks and alternatives, and voluntariness; documentation of the discussion is essential.

Capacity assessment: patient can understand, retain, weigh, and communicate a decision; if lacking, best-interest decisions with advance directives or proxy.

Confidentiality: patient information may be shared only with consent or where required by law (public health, serious crime, court order); minimum necessary disclosure.

Duty of candour: disclose harm to patients openly and apologise; this is an ethical and increasingly legal obligation in many jurisdictions.

Conflict of interest: declare financial and non-financial interests; avoid influencing clinical recommendations (e.g., device selection).

Professional boundaries: avoid treating family or close friends when possible; document any exception and ensure objective care.

End-of-life decisions in vascular patients: discuss goals of care, ceilings of treatment, and palliative options for non-reconstructable limb ischaemia.

Documentation standards: contemporaneous, legible, signed, dated, and factual; the medical record is a legal document and may be discoverable.

WHO surgical safety checklist: sign-in, time-out, sign-out; reduces surgical morbidity and mortality when used consistently.

Quality metrics in vascular surgery: 30-day mortality, major amputation-free survival, graft patency, surgical site infection, length of stay, and readmission.

Root cause analysis: structured review of adverse events to identify system failures; focus on process, not blame.

Plan-Do-Study-Act (PDSA) cycles drive iterative quality improvement; measure before and after each change.

Evidence hierarchy: systematic reviews/meta-analyses of RCTs > RCTs > cohort studies > case series > expert opinion.

Critical appraisal: assess randomisation, blinding, allocation concealment, sample size, and intention-to-treat analysis before applying trial results.

Audit vs research: audit measures practice against a standard and closes the loop; research generates new knowledge and requires ethics approval.

National vascular registries (e.g., VASCUNET, NVR) provide benchmarked outcomes and support shared decision-making and service improvement.