Duplex Ultrasound of Renal and Mesenteric Arteries: Stenosis According to ESVS 2025
What ESVS 2025 Recommendations Changed
ESVS 2025 for the first time combined diseases of the mesenteric and renal arteries and veins in one vascular document. For the ultrasound diagnostician, two practical positions are important: duplex scanning is the first line for suspected renal artery stenosis; in chronic mesenteric ischemia after revascularization, duplex is used as the first test when symptoms return.
This does not mean that ultrasound replaces CT angiography or MR angiography before intervention. The role of duplex is to quickly identify hemodynamically significant lesions, assess the side and level of stenosis, confirm restenosis in the reconstruction zone, and determine when anatomical visualization is needed.
Renal Artery: When Duplex is the First Line
The study is indicated for clinical suspicion of renovascular hypertension, deterioration of kidney function with suspected ischemic nephropathy, kidney asymmetry, unexplained worsening of blood pressure control, and before deciding on additional angiovisualization. According to ESVS 2025, duplex is rational as a starting method because it does not require contrast, does not carry radiation exposure, and simultaneously evaluates the kidney, parenchymal blood flow, and the main vessel.
The protocol should describe the ostium, proximal, middle, and distal segments of the renal artery, as well as intrarenal spectra. If ostium visualization is impossible, the conclusion should not mimic an exact stenosis grading: diagnostic limitations should be indicated, and CTA or MRA should be recommended if clinical suspicion persists.
Ultrasound Signs of Renal Artery Stenosis
A direct sign is local blood flow acceleration in the narrowing zone with post-stenotic turbulence. Indirect signs include delay and smoothing of the systolic rise in segmental or interlobar arteries, interrenal spectral asymmetry, and decreased perfusion of the corresponding kidney. The link between 'morphology plus hemodynamics' is important: isolated PSV elevation without post-stenotic changes may result from tortuosity or angle error, while indirect tardus-parvus without ostium visualization does not localize stenosis.
For the native renal artery in clinical practice, an ESVS-oriented report should include peak systolic velocity in the stenosis zone, aortic velocity at the level of the renal arteries, and the renal-aortic ratio. Suspected occlusion requires the absence of detectable flow in the lumen with a technically adequate study and assessment of collateral/intrarenal signals.
Mesenteric Arteries: When Duplex is Needed
In the primary diagnosis of chronic mesenteric ischemia, anatomical visualization is often necessary for treatment planning. However, after endovascular or open revascularization, the return of postprandial pain, reduced nutrition, or other typical symptoms requires a quick search for restenosis. In this situation, ESVS 2025 assigns duplex the role of the first test.
The study includes the celiac trunk, superior mesenteric artery, and, when technically possible, the inferior mesenteric artery. For chronic ischemia, not only the velocity in one vessel is important, but also the overall anatomy: isolated lesions and multi-vessel lesions have different clinical significance.
Threshold Logic and What to Write in the Conclusion
| Vessel/Scenario | Threshold or Classification Applied in ESVS 2025 Logic | Practical Significance for Ultrasound Conclusion |
|---|---|---|
| Renal artery, native vessel | Hemodynamically significant stenosis is assessed by a combination of local PSV, renal artery/aorta ratio, and direct/indirect signs | Do not indicate percentage based on a single PSV; describe the segment, maximum velocity, turbulence, and intrarenal spectra |
| Chronic mesenteric ischemia, single-vessel lesion | Clinically significant benchmark is stenosis of the celiac trunk or SMA ≥70% | With typical symptoms, such a result requires anatomical confirmation and discussion of revascularization |
| Chronic mesenteric ischemia, multi-vessel lesion | SMA stenosis ≥50% can be clinically significant | Even moderate SMA lesions are important if other mesenteric arteries are simultaneously affected |
| Recurrence of symptoms after mesenteric revascularization | Duplex is the first test for searching for restenosis or occlusion in the reconstruction zone | Compare with early postoperative study, indicate velocity in the stent/anastomosis, and presence of post-stenotic turbulence |
How to Distinguish True Stenosis from Artifact
Main causes of false velocity elevation include artery tortuosity, respiratory shifts, compression of the celiac trunk by the median arcuate ligament, calcinosis with acoustic shadow, incorrect Doppler beam direction, and measurement not in the maximum velocity stream. Therefore, the spectrum should be obtained in the narrowest visible section, and color Doppler is used to search for aliasing and post-stenotic turbulence.
For the celiac trunk, it is useful to consider respiratory dependence. If acceleration is pronounced mainly on exhalation and decreases on inhalation, a dynamic compression component is possible. In the conclusion, it is better to describe this as probable extravascular compression rather than fixed atherosclerotic stenosis.
After Revascularization: What Changes
In the stent and anastomosis zone, velocities may be higher than in the native vessel, even without clinically significant restenosis. Therefore, the value lies not in a single number but in dynamics: velocity increase compared to baseline postoperative study, appearance of post-stenotic turbulence, worsening distal spectra, and coincidence with symptom recurrence.
For mesenteric arteries, when symptoms recur after treatment, duplex allows for a quick decision on whether there is a hemodynamic cause. If the data is positive or the study is technically limited, the next step is usually CT angiography or MR angiography for planning repeat intervention.
Minimal Protocol Template
- Renal arteries: visualized segments on the right and left, maximum PSV, ratio to aorta, presence of turbulence, intrarenal spectra, size, and echostructure of the kidneys.
- Celiac trunk: patency, zone of maximum velocity, respiratory relationship, post-stenotic changes.
- SMA: ostium and proximal segment, maximum velocity, turbulence, distal blood flow.
- Post-intervention: type of reconstruction, patency of the stent or anastomosis, comparison with previous duplex, signs of restenosis or occlusion.
- Limitations: gas, obesity, calcinosis, incomplete ostium visualization, inability to reliably register spectra.
When Ultrasound is Not Enough
Duplex should not delay anatomical visualization in cases of high clinical probability of significant lesions and technically uninformative study. For renal arteries, this is especially important with non-visualized ostium, suspected accessory arteries, or fibromuscular dysplasia. For the mesenteric circulation, it is crucial in cases of significant calcinosis, after complex reconstruction, and when there is a discrepancy between symptoms and ultrasound findings.
The optimal conclusion formulation is not 'stenosis excluded,' but 'no hemodynamically significant signs of stenosis in segments available for assessment' or 'study limited, CTA/MRA required.' This approach corresponds to the role of duplex in ESVS 2025: first-line screening and monitoring, but not a universal replacement for angiographic anatomy.
Frequently asked questions
Can the diagnosis of renal artery stenosis start with duplex according to ESVS 2025?
Yes. Duplex ultrasound is indicated as a first-line method for suspected renal artery stenosis; CTA or MRA is needed for uninformative studies and before planning intervention.
Which mesenteric stenosis is considered clinically significant in chronic ischemia?
In the ESVS 2025 logic, for single-vessel lesions, the benchmark is stenosis of the celiac trunk or SMA ≥70%; in multi-vessel lesions, SMA stenosis ≥50% can be significant.
What is more important in renal artery ultrasound: PSV or renal-aortic ratio?
No single parameter should be used in isolation. The conclusion should consider local acceleration, the velocity ratio of the renal artery to the aorta, post-stenotic turbulence, and intrarenal spectra.