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Published on: August 8, 2025
Sheath-to-Artery Diameter Ratio: A Robust Predictor of Early Access-Site Adverse Events in Percutaneous Procedures
Eduardo Ismael Arteaga Chan1, Claudia Lerma1, Adriana Torres-Machorro1,2
1Universidad Nacional Autónoma de México, UNAM, Mexico City, Mexico.
Insights
A high sheath-to-artery diameter (SHAD) ratio (≥1.07) strongly predicts vascular access site complications (VASCs) after large-bore femoral interventions. Maintaining a ratio ≤1.0 with image-guided access can significantly reduce these risks.
Area of Science:
- Cardiovascular Interventions
- Vascular Surgery
- Medical Imaging
Background:
- Vascular access site complications (VASCs) are a significant cause of morbidity following percutaneous interventions.
- The sheath-to-femoral artery ratio is a known risk factor in transcatheter aortic valve implantation (TAVI), but its broader applicability is unclear.
Purpose of the Study:
- To assess the association between the sheath-to-artery diameter (SHAD) ratio and early VASCs in patients undergoing femoral percutaneous interventions using sheaths >6 Fr.
- To identify optimal SHAD ratio cutoffs for predicting complications.
Main Methods:
- A nested case-control study within a retrospective cohort of 2660 patients.
- 177 patients with VASCs within 7 days were compared to 353 propensity score-matched controls.
- The SHAD ratio was calculated from pre-procedural computed tomography angiography (CTA).
Main Results:
- A SHAD ratio ≥1.07 was a robust predictor of VASCs (OR 6.71, p<0.001), with an AUC of 0.83.
- Higher SHAD ratios were observed in patients with VASCs (1.26) compared to controls (0.75).
- Dual femoral access and procedural urgency increased risk, while ultrasound- or fluoroscopy-guided access were protective.
Conclusions:
- A SHAD ratio ≥1.07 reliably predicts early VASCs in large-bore femoral interventions.
- Maintaining a sheath-to-artery relationship ≤1.0 and using image-guided access may significantly decrease complications.
- Pre-procedural SHAD assessment is recommended, pending external validation.
Background:
Vascular access site complications (VASCs) remain an important source of morbidity following percutaneous interventions. Although the sheath-to-femoral artery ratio is a recognized risk factor in transcatheter aortic valve implantation (TAVI), its role across a broader range of femoral procedures is less well defined.
Objective:
To evaluate the association between the sheath‑to‑artery diameter (SHAD) ratio and early VASCs in patients undergoing femoral percutaneous interventions with sheaths > 6 Fr.
Methods:
A nested case-control study was performed within a retrospective cohort of 2660 consecutive patients. A total of 177 patients who developed VASCs within 7 days were identified and compared with 353 propensity score-matched controls without complications. The propensity score included age, sex, body mass index, hypertension, diabetes mellitus, peripheral artery disease, and prior femoral access. The SHAD ratio was calculated using pre‑procedural computed tomography angiography (CTA). Inter‑observer agreement for arterial diameter was excellent (intraclass correlation coefficient 0.94). Receiver operating characteristic analysis identified the optimal cutoff (Youden index), and multivariable logistic regression with backward stepwise selection was internally validated by bootstrap. Anatomical factors (calcification, tortuosity) were examined as potential confounders.
Results:
After matching, all baseline characteristics were well balanced (standardized differences < 0.10). The SHAD ratio was significantly higher in patients with VASCs than in controls (1.26 vs. 0.75; p < 0.001). A SHAD ratio ≥ 1.07 optimally predicted complications (AUC 0.83, 95% CI 0.80-0.87; sensitivity 82%; specificity 78%). In the final multivariable model, SHAD ≥ 1.07 remained the strongest independent predictor (OR 6.71, 95% CI 3.87-11.64; p < 0.001). Dual femoral access (OR 2.95, 95% CI 1.65-5.28) and procedural urgency (OR 1.98, 95% CI 1.18-3.32) also increased risk. Ultrasound‑guided puncture (OR 0.15, 95% CI 0.08-0.28) and fluoroscopy‑guided access (OR 0.14, 95% CI 0.07-0.26) were strongly protective. Anterior wall calcification was associated with a higher complication risk in univariable analysis but did not remain significant after adjustment for SHAD. Bootstrap internal validation yielded an optimism‑corrected AUC of 0.91 (95% CI 0.89-0.93), indicating good discrimination.
Conclusions:
A SHAD ratio ≥ 1.07 is a robust predictor of early VASCs across multiple large‑bore femoral interventions. Maintaining a sheath‑to‑artery relationship ≤ 1.0, together with image‑guided access, may substantially reduce complications. The incorporation of SHAD assessment into pre‑procedural planning is supported, pending external validation.