Stents are associated with increased risk of respiratory infections in patients undergoing airway interventions for malignant airways disease

Abstract

Background: Long-term complications of therapeutic bronchoscopy include infections and airway restenosis due to tumor. No studies have compared the incidence rates of infection in patients with stents with those without stents. We hypothesized that patients with stents would have a higher incidence of lower respiratory tract infections than would patients without stents.

Methods: We conducted a retrospective cohort study, covering the period September 2009 to August 2011, of patients who had therapeutic bronchoscopy for malignant airways disease. Outcomes recorded were lower respiratory tract infection and airway restenosis by tumor.

Results: Seventy-two patients had therapeutic bronchoscopy for malignant airways disease. Twenty-four of these patients had one or more stents placed. Twenty-three of the 72 patients (32%) developed lower respiratory tract infections. Stents were associated with an increased risk of infection (hazard ratio [HR], 3.76; 95% CI, 1.57-8.99; P = .003). The incidence rate of lower respiratory tract infection was 0.0057 infections per person-day in patients with stents vs 0.0011 infections per person-day in patients without stents. The incidence rate difference, 0.0046 infections per person-day, was significant (95% CI, 0.0012-0.0081; P = .0002). Restenosis due to tumor overgrowth was associated with more severe obstruction at baseline (obstruction ≥ 50% vs < 50% preprocedure; HR, 13.71; 95% CI, 1.75-107.55; P = .013).

Conclusion: Therapeutic bronchoscopy with stent placement is associated with a higher risk of infection than is therapeutic bronchoscopy alone. If ablative techniques reopen the airway and there is a good chance that the tumor may respond to chemotherapy and/or radiation, a strategy of initially holding off on stenting may be warranted.

Figure 1.

Kaplan-Meier plots of time to first infection. A, Stent vs no stent. Patients with stents (dashed line) had a significantly shorter time to infection than did patients without stents (solid line). B, Male vs female patients. Female patients (solid line) had a significantly shorter time to infection than did male patients (dashed line).

Figure 2.

Kaplan-Meier plots of time to tumor overgrowth. A, Preprocedure obstruction < 50% (solid line) vs preprocedure obstruction ≥ 50% (dashed line). B, No stent in place (solid line) vs stent in place (dashed line).

Figure 3.

Kaplan-Meier plot of time to death. Patients who did not require stenting initially, who received chemotherapy after therapeutic bronchoscopy with ablation, did the best (solid line). Patients who did not require stenting initially, who did not receive chemotherapy (dashed line), and patients who required stenting, who received chemotherapy (dashed-dotted line), had intermediate outcomes. Patients who required stenting, who did not receive chemotherapy (dotted line), had the worst survival (log-rank P < .0001).