Obesity Does Not Significantly Impact Operative and Long-Term Outcomes After Pulmonary Thromboendarerectomy

Abstract

<h3>Purpose</h3> Although obesity is a common comorbidity among patients undergoing Pulmonary Thromboendarterectomy (PTE) for Chronic Thromboembolic Pulmonary Hypertension (CTEPH), the exact impact of this risk factor on operative and hemodynamic outcomes remains poorly described. Objectives are to assess the effects of BMI on operative mortality and major morbidity, survival, and post-discharge hemodynamic parameters after PTE. <h3>Methods</h3> From 2013 to 2021, 223 patients underwent PTE at a single referral institution. Median age was 51±15 years and mean BMI was 33.6±8.8kg/m². Diagnosis of CTEPH was confirmed on pulmonary artery catheterization with mean PA pressure 45.4±12.2mmHg. The primary outcome was a composite of in-hospital mortality, stroke, respiratory failure requiring tracheostomy and renal failure requiring dialysis. Secondary outcomes included late changes to hemodynamic parameters and sternal wound infection. <h3>Results</h3> In-hospital mortality was 6.3% (N=14), while 1.3% of patients (N=3) suffered stroke, 5.4% (N=12) required dialysis and 9.0% (N=20) required tracheostomy. Post-operative mean PA pressure was 30.4±9.6 mmHg just prior to discontinuation of invasive monitoring. Of the 106 patients with post-discharge echocardiogram, 12% had moderate-severe RV dysfunction, decreased from 53% pre-operatively (p=0.0004). Eighteen (8.1%) patients required reintervention for post-operative sternal infection, with 7 deep and 11 superficial infections. Of these, 12 required debridement and 6 required tissue flap. In a univariate logistic regression, BMI was not a significant predictor of the composite outcome (OR 1.00, CI 0.96-1.04), but was correlated with increased risk of wound infection (OR 1.06, CI 1.01-1.11). Changes to in-hospital PA pressures and post-discharge RV function were not correlated with BMI (p=0.97, p=0.96, respectively). In a Cox proportional hazards model, BMI was not associated with impaired long-term survival after PTE (HR 1.01, CI 0.96-1.06). <h3>Conclusion</h3> This study shows that PTE can be a safe and effective treatment for CTEPH in the obese population, although it does carry increased risk of post-operative wound infection. PTE has the potential to yield excellent hemodynamic results in all patients, regardless of BMI; and therefore, it should continue to represent the standard of care for obese patients with CTEPH.