Veno-Venous Extracorporeal Lung Support as a Bridge to or Through Lung Volume Reduction Surgery in Patients with Severe Hypercapnia

Nonintubated versus Intubated Lung Volume Reduction Surgery in Patients with End-Stage Lung Emphysema and Hypercapnia

Lung volume reduction surgery (LVRS) represents an important treatment option in carefully selected patients with end-stage lung emphysema. The aim of this study was to assess the efficacy and safety of nonintubated LVRS compared to intubated LVRS in patients with preoperative hypercapnia and lung emphysema. Between April 2019 and February 2021, n = 92 patients with end-stage lung emphysema and preoperative hypercapnia undergoing unilateral video-assisted thoracoscopic LVRS (VATS-LVRS) performed in epidural anesthesia and mild sedation (nonintubated, group 1) or conventional general anesthesia (intubated, control, group 2) were prospectively enrolled in this study. Data were retrospectively analyzed. In all patients, low-flow veno-venous extracorporeal lung support (low-flow VV ECLS) was applied as a bridge through LVRS. Ninety-day mortality was considered as the primary outcome. Secondary endpoints included: chest tube duration, hospital stay, intubation and conversion to general anesthesia. Intergroup analysis showed no significant difference between the baseline data and patients' demographics. N = 36 patients underwent nonintubated surgery. VATS-LVRS under general anesthesia was performed in n = 56 patients. The mean duration of postoperative VV ECLS support was 3 ± 1 day in group 1 compared to 4 ± 1 in group 2. The 90-day mortality rate was 3% in group 1 compared to 7% in group 2. In group 1, all chest tubes were removed 5 ± 1 day (range 4-32 days) and 8 ± 1 day (range 4-44 days) in the control group after the surgery (p < 0.02). Prolonged chest tube therapy (>8 days) was observed in n = 3 patients in group 1 and n = 11 patients in the control group. The mean ICU stay was 4 ± 1 days in group 1 compared to 8 ± 2 days in the control group (p = 0.04). The mean hospital stay was significantly shorter in the nonintubated group 1 (6 ± 2 days vs. 10 ± 4 days, p = 0.01). Conversion to general anesthesia was necessary in one patient due to severe pleural adhesions. Nonintubated VATS-LVRS in patients with end-stage lung emphysema and hypercapnia is effective and well tolerated. Compared to general anesthesia, a reduction in mortality, chest tube duration, ICU and hospital stay and lower rate of prolonged air leak was observed. VV ECLS increases intraoperative safety and mitigates postoperative complications in such "high-risk" patients.

Lung Volume Reduction Surgery Reduces Pulmonary Arterial Hypertension Associated With Severe Lung Emphysema and Hypercapnia

Lung volume reduction surgery (LVRS) represents a standard surgical approach for patients with severe pulmonary emphysema. One of the relevant risk factors for LVRS is the presence of pulmonary arterial hypertension (PAH). The aim of this study is to assess the postoperative changes in pulmonary arterial pressure (PAP) after LVRS for patients with severe pulmonary emphysema compared with preoperative measures. N = 61 consecutive patients with severe pulmonary emphysema and preoperative evidence for PAH (pulmonary arterial systolic pressure [PASP] ≥ 35 mmHg) were prospectively included into this study. In all patients, thoracoscopic LVRS was performed. PASP was assessed by echocardiography before surgery, early postoperatively, and 3 months after surgery. Data were prospectively recorded and analyzed retrospectively. Primary end points were the postoperative changes in PASP as well as the 90 day mortality rate. Secondary endpoints included: pulmonary function test, exercise capacity, quality of life, and dyspnea symptoms (Borg scale). Early after surgery, a significant reduction in PASP was observed at the day of discharge and at 3 month follow-up. In n = 34 patients, no tricuspid valve regurgitation was detectable anymore suggesting normal PAP. In n = 3 patients, venovenous extracorporeal lung support (VV ECLS) was already implemented preoperatively. In the remaining cases, VV ECLS was applied intraoperatively and continued postoperatively. Mean duration of postoperative ECLS support was 2 days. Four patients died due to acute right heart failure, two patients from sepsis with multiorgan failure, and one patient from acute pulmonary embolism. Ninety day mortality was 11.5 %. A significant improvement was postoperatively observed regarding the performance status, dyspnea scale, as well as quality of life. This study suggests a beneficial effect of LVRS on PAP, which may ultimately help to protect and stabilize right ventricular function. Further studies, implementing pre- and postoperative right heart catheterizations including invasive PAP evaluation, are necessary to support the findings in this study in greater detail.

Extracorporeal Membrane Oxygenation Use in Thoracic Surgery

This narrative review is focused on the application of extracorporeal membrane oxygenation (ECMO) in thoracic surgery, exclusive of lung transplantation. Although the use of ECMO in this indication is still rare, it allows surgery to be performed in patients where conventional ventilation is not feasible-especially in single lung patients, sleeve lobectomy or pneumonectomy and tracheal or carinal reconstructions. Comparisons with other techniques, various ECMO configurations, the management of anticoagulation, anesthesia, hypoxemia during surgery and the use of ECMO in case of postoperative respiratory failure are reviewed and supported by two cases of perioperative ECMO use, and an overview of published case series.