ABS Vascular Surgery common mistakes
ABS Vascular Surgery · Understand the traps and how to avoid them.
Applying a single 5.5 cm repair threshold to every infrarenal AAA, including women, and ignoring growth rate, symptoms, or sac morphology when deciding on elective repair.
Candidates memorise one number from a landmark trial (which enrolled overwhelmingly men) and never layer on sex-specific and morphology-specific modifiers, so they under-offer repair to women and to patients with rapidly expanding or saccular aneurysms.
What to do instead
Build a decision checklist before answering any AAA question: diameter threshold 5.5 cm in men and 5.0 cm in women; growth >=0.5 cm in 6 months or >=1 cm in a year; symptomatic, ruptured, or saccular/branch-containing aneurysm goes urgently regardless of size. State the sex and the growth rate explicitly in your reasoning so the threshold you apply is visible.
Recommending standard EVAR for a patient whose infrarenal neck is short, angulated, reverse-tapered, or lined with circumferential thrombus/calcification, without measuring the seal zone.
The procedural appeal of EVAR dominates the reasoning, and candidates do not routinely translate CT anatomy into device instructions-for-use: they quote 'neck length' from the lowest renal artery to the aneurysm without checking angulation, taper, or mural thrombus that prevents seal.
What to do instead
For every EVAR question, force yourself through five measurements on a centreline: proximal neck length, neck diameter, infrarenal angulation, reverse taper, and seal-zone calcification/thrombus. If the neck is under about 10-15 mm, angulated more than 60 degrees, or heavily diseased, say that standard EVAR is outside instructions for use and name the alternatives - fenestrated/branched EVAR, chimney, surgeon-modified graft, or open repair - plus the specific complication you are avoiding (type Ia endoleak, graft migration).
Measuring carotid stenosis with the wrong denominator - estimating the bulb diameter at the level of maximal narrowing (the ECST-style method) and reporting it as a NASCET percentage - and separately deferring carotid endarterectomy beyond two weeks after the index symptom.
Both methods are taught together, the bulb is the visually obvious narrow point, and timing is treated as a scheduling detail rather than a determinant of benefit, so the candidate reports an inflated stenosis and schedules surgery at convenience.
What to do instead
Recite the NASCET formula aloud: 100 x (1 - narrowest residual lumen / normal distal internal carotid diameter measured beyond the bulb). Anchor it: NASCET 70% roughly equals ECST 80%. Then pair the number with the indication and the clock - symptomatic 70-99% operates within 14 days (benefit greatest in the first two weeks), 50-69% is a moderate-benefit discussion, below 50% is medical therapy only.
Treating every leg symptom as claudication, and every claudication as an indication for intervention, without separating lifestyle-limiting claudication from chronic limb-threatening ischaemia or from pseudoclaudication.
Pattern-matching to 'leg pain equals PAD' is fast and feels safe, so candidates skip the discriminating features - walking distance, relief time, positional triggers, rest pain, tissue loss - and default to angiography and revascularisation for symptoms that are neurogenic, venous, or genuinely mild.
What to do instead
Classify before you treat: true claudication reproduces at a fixed distance and resolves within 2-5 minutes of standing still; neurogenic pseudoclaudication is relieved by sitting or leaning forward and is not fixed-distance; venous claudication is a bursting tightness relieved by elevation. Chronic limb-threatening ischaemia requires rest pain (typically nocturnal, relieved by dependency), tissue loss, or gangrene, usually with ankle pressure under 50-70 mmHg or toe pressure under 30-50 mmHg. Say the category out loud, then justify exercise/supervised therapy versus revascularisation from that category.
Diagnosing chronic mesenteric ischaemia late or mislabelling it, and reporting the site of an acute superior mesenteric artery occlusion without linking it to embolic versus thrombotic pattern.
Postprandial pain and food fear are misattributed to gastritis or malignancy, the workup drifts to endoscopy, and the classic teaching that emboli lodge distal to the middle colic origin while thrombosis occurs at the ostium is recalled vaguely rather than applied to the imaging described.
What to do instead
Keep a two-line script. Chronic: weight loss plus postprandial pain plus food fear in a patient with atherosclerosis or a smoker, diagnosed on CTA showing ostial disease of at least two of the three visceral vessels - not on symptoms alone. Acute: pain out of proportion to examination with a rising lactate and often a relatively normal early film; embolic occlusion sits distal to the middle colic artery and spares the proximal jejunal branches, thrombotic occlusion sits at the ostium. State which pattern is present and how it changes the operation (embolectomy and resection versus bypass).
Accepting a normal or high ankle-brachial index as proof of adequate perfusion in a diabetic or dialysis patient, and never escalating to toe pressures, waveform analysis, or transcutaneous oximetry.
The ABI is the first test learned and the easiest to report, but medial calcinosis makes ankle vessels incompressible, giving falsely reassuring values above 1.3-1.4 in exactly the patients who need accurate assessment most.
What to do instead
When the ABI exceeds 1.3-1.4, or the tracing is monophasic/biphasic with a high reading, declare the study non-diagnostic and move to toe-brachial index (abnormal below about 0.7), continuous-wave Doppler waveforms, or transcutaneous oxygen. In the vascular laboratory domain, also state the technical requirements before quoting velocities: 60-degree insonation angle, sample volume in the narrowest segment, and internal carotid peak systolic velocity above 125 cm/s for 50% stenosis and above 230-250 cm/s with an internal-to-common carotid ratio above 3.5-4.0 for 70%.
Prescribing a blanket three months of anticoagulation for every deep vein thrombosis, and placing an inferior vena cava filter as routine therapy rather than as a contraindication-driven decision.
Provoked and unprovoked thrombosis are recorded as one diagnosis, so recurrence risk and bleeding risk never enter the plan; filters feel like a mechanical safeguard and the absolute indication is blurred with 'high bleeding risk' in general.
What to do instead
At the moment you write 'DVT', force three tags: provoked (surgery, immobilisation, oestrogen, pregnancy) versus unprovoked versus cancer-associated; proximal versus isolated calf; and bleeding risk. Three months is standard for provoked proximal DVT; unprovoked or cancer-associated disease warrants extended therapy with periodic reassessment of the bleeding-to-recurrence balance. An IVC filter is indicated only when anticoagulation is contraindicated or has failed despite therapeutic levels - and it is not a substitute for anticoagulation once bleeding risk resolves.
In vascular trauma, ordering duplex or elective CTA for a limb with hard signs of arterial injury, and conversely clearing a limb with soft signs on a single normal examination without an ankle-brachial index or interval reassessment.
The imaging-first reflex from elective practice transfers inappropriately, and candidates cannot distinguish the two sign sets, so they either delay an exsanguinating patient or miss an intimal flap that will thrombose hours later.
What to do instead
Split the signs explicitly. Hard signs - pulsatile or expanding haematoma, active haemorrhage, absent distal pulse, bruit or thrill, distal ischaemia - mean immediate operative exploration or on-table angiography, not a duplex. Soft signs - stable small haematoma, unexplained neurological deficit, proximity injury - mean ABI and CTA. An ABI below 0.9 after trauma mandates imaging regardless of a normal pulse, and any limb with a reduced index needs repeat assessment before discharge.
Describing a post-EVAR endoleak without classifying it, or treating every type II endoleak with reintervention.
Endoleak is recalled as a single word, so the candidate cannot map the finding to the mechanism, the urgency, or the surveillance interval, and defaults either to 'observe' for a type I or 'embolise' for a benign type II.
What to do instead
Classify by attachment site before answering. Type I and type III (component separation or fabric defect) are seal failures - treat, since the sac stays pressurised. Type II is retrograde branch flow - observe, and intervene only for continuing sac growth. Type IV is graft porosity - transient, observe. Type V is endotension without a visible leak - surveillance with sac trend. Pair the classification with the surveillance schedule: CTA at one month, twelve months, then annually, with sac diameter, not leak presence alone, driving decisions.
Stopping aspirin or statin therapy 'for surgery', starting a high-dose beta blocker on the morning of vascular surgery, and bridging every anticoagulated patient with heparin regardless of indication.
Generic perioperative rules are imported from non-vascular practice where bleeding risk dominates, and the trial evidence - that antiplatelets and statins reduce vascular graft and cardiac events, that acute high-dose beta blockade increases stroke and death, that bridging increases bleeding without reducing thromboembolism in atrial fibrillation - is not retrieved under time pressure.
What to do instead
Run a fixed medication checklist for every vascular patient. Continue aspirin and statin through carotid endarterectomy, aortic surgery, and infrainguinal bypass unless a specific contraindication exists. Do not initiate high-dose beta blockade on the day of surgery; continue an existing dose and titrate preoperatively when indicated. Bridge only for high-thrombotic-risk situations such as recent mechanical mitral valve or recent venous thromboembolism, not routinely for atrial fibrillation. Add the two other high-yield perioperative issues to the same checklist: spinal cord ischaemia after extensive thoracic aortic coverage (CSF drainage and mean arterial pressure targets) and abdominal compartment syndrome after ruptured AAA repair.
Selecting an amputation level from the extent of tissue loss alone, without assessing healing potential by perfusion, and proceeding to major amputation without first addressing revascularisation and offloading.
The visible wound drives the decision and the candidate does not connect the level to measurable perfusion or to rehabilitation outcome, so a salvageable limb is lost above the knee or a below-knee amputation is chosen in a limb that will not heal.
What to do instead
Tie the level to numbers and to function. Below-knee amputation is preferred when healing potential exists - palpable popliteal pulse, calf-level Doppler systolic pressure above about 70 mmHg, or transcutaneous oxygen above 30-40 mmHg - because knee preservation lowers energy cost of walking and improves rehabilitation. Choose above-knee for a non-ambulatory patient, fixed knee flexion contracture, or necrosis extending above the tibial plateau. Before any major amputation, confirm that revascularisation has been considered, that the diabetic foot has been offloaded, and that infection and tissue loss have been debrided; state the wound-care plan and the prosthesis pathway, not just the level.