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Background: Obesity is increasing in the United States; however its impact on adverse outcomes in patients with peripheral vascular disease is not well studied. Prior literature found higher rates of complications following open bypass surgery. However, limited data are available on the impact of obesity following endovascular intervention. This study aims to identify whether obese patients suffer the same complications when undergoing lower extremity endovascular interventions.
Methods: Patients who underwent femoral or tibial endovascular interventions between 2011 and 2013 were identified in the Targeted Vascular module of the NSQIP. Patients were stratified into five groups based on their body mass index (BMI): underweight (<18.6), normal weight (18.6-25), pre-obese (25-30), obese (30-35) and morbidly obese (>35). Patients without a documented BMI or a defined target lesion were excluded. Patient characteristics, operative details, and outcomes were compared using univariate analysis between the BMI groups. Multivariable logistic regression was utilized to account for patient demographics and operative details.
Results: 3246 patients underwent endovascular interventions (78% femoral and 22% tibial). Of these, 137 (4%) were underweight, 881 (27%) normal weight, 1193 (37%) pre-obese, 647 (20%) obese and 338 (12%) morbidly obese. Wound infection was significantly higher (morbidly obese: 5.2% vs normal weight: 2.3%, P=0.02), whereas untreated patency loss was significantly lower (morbidly obese: 0.5%, obese: 0.9%, normal weight: 2.3%, P=0.02). Amputation rates were lower, though not statistically significant (obese: 2.3% vs normal weight: 4.5%, P=0.15). Other important 30-day outcomes, including 30-day mortality and bleeding, were similar across the BMI groups (Table 1). Following multivariate analysis, wound infection (OR: 2.6, 95% CI: 1.4-5.0) and untreated patency loss (OR: 0.2, 95% CI: 0.05-0.85) remained significant in morbidly obese patients. Amputation was significantly lower in the obese (OR: 0.5, 95% CI: 0.28-0.98).
Conclusion: Post-operative wound infections occur more frequently in morbidly obese patients following open bypass or endovascular intervention. Additionally, they undergo treatment less frequently after patency loss. However, obesity is not an independent predictor of other major adverse outcomes, and has actually shown a protective effect in amputation. Given this knowledge, careful consideration should be made when choosing the appropriate surgical intervention in this patient population.

Table 1: Outcomes Following Endovascular Intervention Among BMI Groups

Outcome Number (%)	Underweight (<18.6)	Normal Weight (18.6-25)	Pre-Obese (25-30)	Obese (30-35)	Morbidly Obese (>35)	P-Value
30-day Mortality	1 (0.7)	22 (2.5)	16 (1.3)	10 (1.5)	7 (1.8)	0.28
Wound Infection	2 (1.5)	20 (2.3)	28 (2.3)	22 (3.4)	20 (5.2)	0.023
Patency Loss	4 (2.9)	20 (2.3)	12 (1.0)	6 (0.9)	2 (0.5)	0.017
Amputation	4 (2.9)	40 (4.5)	48 (4.0)	15 (2.3)	11 (2.8)	0.153
Bleeding	9 (6.6)	74 (8.4)	78 (6.5)	41 (6.3)	33 (8.5)	0.35
Myocardial Infarction/Stroke	0	16 (1.8)	13 (1.1)	7 (1.1)	5 (1.3)	0.358
Reintervention	8 (5.8)	29 (3.3)	47 (3.9)	21 (3.2)	17 (4.4)	0.531
Renal Complication	2 (1.5)	9 (1.0)	7 (0.6)	4 (0.6)	6 (1.5)	0.347
Readmission	23 (16.9)	114 (13.0)	175 (14.7)	78 (12.1)	59 (15.2)	0.32