RIght VEntricle Response to Major Lung Resection in VATS and Robotic Surgery

Overview

Major pulmonary resection is associated with high postoperative morbidity and mortality, mainly due to cardiorespiratory complications. Right ventricular (RV) function is closely related to pulmonary artery pressure and tone, and it is particularly sensitive to changes in afterload. An increase in RV flow resistance can lead to acute RV dilation and reduced left ventricular compliance, potentially progressing to cardiogenic shock. In a previous study (RIVER), it was observed that increased afterload following open thoracic surgery reduces RV function, although this impairment remains subclinical. The aim of this study is to investigate the same parameters in patients with severe cardiovascular comorbidities undergoing pulmonary resection via minimally invasive approaches (VATS and robotic surgery) compared to open thoracotomy.

* Major lung resection is associated with high postoperative morbidity and mortality and significant long-term decreased functional capacity, especially due to cardiorespiratory complications \[2\]. An overall cardiovascular performance assessment is usually carried out before this type of surgery, along with pulmonary function tests. In such a context, close attention to the right ventricle (RV) function is recommended. * The RV is known to be exquisitely sensitive to changes in afterload\[3,4\]. Since RV ejection, pulmonary artery pressure (PAP), and tone are tightly coupled, an impairment in pulmonary vascular reserve can compromise RV ejection, increasing right atrial pressure and limiting maximal cardiac output \[5\]. We know that during acute massive pulmonary embolism (PE), the acute increase in RV outflow resistance causes acute RV dilatation and, using ventricular interdependence, markedly decreased left ventricle (LV) compliance, rapidly spiraling to acute cardiogenic shock and death. We want to explore if during major lung surgery such maneuvers as pulmonary artery branch clamping could bring to the same event. Furthermore, a postoperative RV disfunction (RVD) has been observed after open major lung surgery; in our previous study we showed that the observed increase in afterload reduced the post-operative RV function after open surgery (thoracotomy), but the impairment remained subclinical, with the RV failure being rarely observed\[3\]. * More in general, this effect has been investigated in literature and all studies agree with the conclusion that the postoperative RV disfunction is common after major lung surgery but there is no evidence of acute cardiogenic shock\[4-9\], neither during clamping nor in the port-operative period, suggesting that the mechanisms involved in the RV response are various (not just RV resistances) and, to date, not well defined. Little is known on RV disfunction after video-assisted thoracoscopic surgery\[10\]. * With this study our aim is to observe the difference in RV disfunction after mini-invasive video-assisted thoracic surgery (VATS and robotic surgery) compared to the open surgical approach, in the hypothesis that the thoracic compliance plays an important role in the cardio-pulmonary balance and it could be more impaired during open surgery. RATIONALE To understand whether and to what extent RV dysfunction occurs after surgery in patients undergoing mini-invasive thoracic surgery and to compare RV function alterations after mini-invasive thoracic surgery to the open apporach.