Hello, my name is William Lynch. I'm a thoracic surgeon at the University of Michigan. Thanks for joining us today for the talk titled complications after lung cancer surgery. The objectives of the talk today will be; first, to review associated mortality and morbidity related to a lung cancer surgery, to discuss patient risk factors, discuss common types of complications, and then to discuss the impact of these complications on mortality and morbidity. So to start, I'll offer a pre-lecture question which will be reviewed again at the conclusion of the talk. Over the years, how have morbidity and mortality rates related to pulmonary resections changed? A, mortality has decreased and morbidity is decreased. B, mortality is increased and morbidity is increased. C, mortality is unchanged, morbidity is decreased. D, mortality is decreased and morbidity is unchanged. So to begin, pulmonary resections are quite common in the setting of lung cancer surgery. As previously discussed in the earlier lectures, lung cancer is one of the most common cancers in the United States, as well a worldwide. Lung cancer is typically present late and in more elderly patients, and because they present late the stage is more advanced and it turns out that only about 20 percent of lung cancer cases are appropriate for resection. But the mortality of lung cancer resection over the course of the past 50 to 60 years has improved over time. In part, this is a consequence of improvements in intra-operative management and post operative care. Interestingly, the morbidity rates have remained stable over the course of the same time frame, and why is that? Well, perhaps, it's because we're operating on older patients which have higher risks and some of these patients are also being exposed to preoperative chemotherapy and radiation. But there is some improvements in management and post-op care and of an increased opportunities to operate on patients that are older and higher risk has allowed us to advance the care, while morbidity rates have remained stable. So, resections for diagnosis and treatment are done in the setting of lung cancer surgery. Lung surgery is also offered to benign diseases. The topic today is focused on just neoplastic diseases. These operations include Wedge resections up to Pneumonectomies and there are a variety of surgical techniques, open techniques, Thoracoscopic techniques which are video-assisted, Thoracoscopic approaches or also referred to as TAS, and then now more recently robotic techniques are being offered in the setting of lung cancer surgery. The mortality is a consequence of most typically cardiovascular in pulmonary complications. Operative mortality has been decreasing over the course of the past 50 years and in part this is a consequence of patient selection. We have now more sophisticated ways of assessing a patient's pulmonary reserve and cardiac reserve, the ability to select patients and limit high-risk operations to those seemed the most benefit from the surgery is now possible. In addition, our approach in the operating room has evolved over the course of time. Intra-operative management, as far as anesthesia is concerned, we now more understand the sensitivity of the lung to high, then later pressures. So, our ability to safely manage a lung has evolved over time. Surgical techniques have also evolved. In the early days of lung cancer surgery, surgical techniques were Hilar dissection or Hilar ligation, and clearly, that is not done commonly anymore, but over the course of time, we've had a better understanding of anatomy and approaches to the anatomy to refine surgical technique making a variety of resections safe and possible. Then finally, post operative management has changed over the course of time. Again, in the ICUs, now we're more sophisticated and comfortable managing ventilators to minimize ventilator associated lung injury. Were more conservative with fluid management. Understanding that pulmonary edema is a consequence of the nature of the operation and puts patient at risk for some of the complications and associated mortalities. The operations we offer have this listed associated mortality rate. A wedge resections should have a mortality rate less than one percent. A Lobectomy should have a mortality rate of under two percent. Pneumonectomy has have a mortality rate of around four percent. There is an association between higher volume centers with less mortality. However, it's very difficult to determine what's considered high and low volume. So, what are the risk factors associated with mortality? Well, age is one risk factor. Again, lung cancer patient is typically an older patient and it's not necessarily the age that's the risk factor but it's the fact that older patients have accumulated multiple comorbidities over the course of their lifetime. Male patient has both increased risk associated with lung cancer but then also has an associated increased mortality and morbidity risks when these operations are offered. Patients who are malnourished have increased mortality risk. Patients with diabetes have increased risk. Patients with chronic lung disease have increased risk, for any type of lung cancer operation. Heart disease is also prevalent in this patient population with increased associated risks of Peri operative cardiac events. Neurologic diseases, put patients at increased risk. More recently, it's clear that delirium, as a consequence of being in a hospital and associated with medications that are offered is an increased risk in this patient population is also at increased risk for dementia and its associated complications. Mortality risk is also associated with peripheral vascular disease, and this is common in the setting of both diabetes and cardiac disease patients. The last three mortality risks mentioned are really risks related to operations and Intra-operative events. Patients have large increase blood volume, losses in the operating room, there's an associated increased mortality. Patients who require more transfusions, which also is associated with Intra-operative blood loss, has increased associated mortality risk. Then patients that receive excessive crystalloid volumes which are used to resuscitate patients who are bleeding, but also is associated by itself with increased mortality risk, most likely related to pulmonary edema and the consequences of respiratory failure. Morbidity, over the course of the past same 50 to 60 years, has really demonstrated minimal improvement in associated incidents. All complications related to lung cancer surgery approaches 40 percent. The same risk factors that we mentioned for mortality apply to morbidity. In addition, it's been noticed that patients who are actively smoking up to the time of surgery, have an increased risk for complication. Patients who are with poor performance status prior to surgery have increased risks of complications and morbidity, and patients who undergo prolonged operations have increased risk for complications. So, what are the typical complications? Bleeding, Prolonged Air leak, Pneumonia, Respiratory Failure, Arrhythmia, Myocardial Infarction, and Deep vein thrombosis and/or pulmonary emboli are commonly seen complications related to lung cancer surgery. This is a partial list but these are the most prevalent. So, what are the bleeding associated issues? Well, the fact that we're resecting lobes or entire lung requires attention to dissection around the hilar structures. The hilar structures include the pulmonary arteries, pulmonary veins, bronchial arteries. In addition, entering the chest puts the Intercostal vessels at risk. The staging that's necessary for lung cancer surgery requires dissection of lymph node beds. Each of these lymph nodes has a feeding vessel which can cause bleeding, both in the operating room but post-operatively. The other structures that are being navigated during the course of variety of lung cancer related operations include the Vena cava, for patients who have large masses in the apex of the chest or towards the media stynum, put the vena cava at risk the chest wall whether it's entering the interspaces for access to the chest or requiring resections of chest wall. Have structures at risk that cause bleeding. Patients who have bulky lymph nodes, are at increased risk for bleeding from dissection of the lymph nodes. Patients who have calcified lymph nodes which can be noticed on CT scans prior to surgery, have increased risk with calcified lymph nodes often mean evidence of inflammatory change that causes lymph nodes to be adherent both to airways as well as the pulmonary arteries. Patients who undergo preoperative radiation, are at increased risk for bleeding as a consequence of the inflammatory change, and then patients who require extra pleural dissections for any reason are at increased risk for bleeding after surgery. About 2-4% of patients who undergo a lung resection have significant bleeding incidence, and about 1.5% of patients require re-exploration for bleeding. Prolonged air leak is probably the most common complication related to lung cancer surgery, that has a rate of approximately seven to 15%. It's defined as an air leak that's longer than seven days, most related to the prolonged air leak is prolonged hospital stay. Patients who require a chest tube to remain in place to manage the air leak, are at increased risk for empyema as a consequence of infection related to the chest tube. So how can this be managed? Well prolonged air leak can initially be addressed in the operating room by trying to avoid that complication. So at the end of the operation the chest can be instilled with either sailing or sterile water in the lung re-inflated, air leaks can be noticed with bubbles streaming from the injured lung parenchyma or the airway. Similar to how you would look for a hole and an inner tube, and at that time you can address the early oftentimes deploying another staple line, but there are also agents that can be covered over the lung tissue surface are sprayed along the surface to try to help minimize and control the air leak. In addition to that, heimlich valve can be used to manage a prolonged air leak, a heimlich valve is a one-way valve that allows air to escape from the chest, avoiding the risk of a tension pneumothorax, but also allowing a chest tube to be managed outside the hospital. Having a patient move on from inpatient hospital care for prolonged period of time. Buttressed staple lines are sometimes used. Staple cartridges can come with pericardial strips that can be used to help secure staple line in the setting of a confersevanas lung and then finally, blood patch has been offered as a strategy of addressing an air leak. A blood patch is simply taking 100 cc's of patients blood and re-infusing that into the chest tube as a way to occlude and obstruct the air leak. Pneumonia is also a common complication after lung cancer surgery. It's associated with patients who have a post-operative atelectasis, which is about four to seven percent of patients after resection. It's associated with increased mortality. Patients who are more likely to have pneumonia after lung cancer surgery are patients who have smoked up to the day of surgery. So preoperative smoking cessation is important strategy of trying to protect the patient from this complication. A patient who's deconditioned and is unable to be out of bed and walking after surgeries are in increase risk. So it's a common strategy to prepare people for surgery by having them be active. So simply walking one to two miles a day on flat level ground, over the course of three to four weeks, can improve a patient's conditioning allowing them to be more capable of walking after surgery. Post-operative pain control is important. A patient who is uncomfortable will not be willing to cough, will not be interested in being out of bed and walking and since those two maneuvers are very important in helping a patient avoid pneumonia, good pain control is necessary. Then again a lot of these strategies are designed in helping a patient be as active as practical, the day of or the day after surgery. Respiratory failure is also a complication of lung cancer surgery, it's related to pneumonia and it can be a life ending consequence of pneumonia. Patients who require prolonged mechanical ventilation, after lung cancer surgery, are at increased risk for persistent respiratory failure. Patients who require excessive volume resuscitation and the course of the operation, are at risk for respiratory failure and then therefore requiring prolonged mechanical ventilation. Patients who have marginal lung function before surgery are also at increased risk for respiratory failure. So careful patient selection, evaluating a patient's potential post-operative remaining lung function is an important adjunct to safely choosing patients and preparing them for safe post-operative care. Patients who have excessive resection, which would be by lobectomies or pneumonectomies, are at increased risk for respiratory failure and pneumonia and again this consequence can be life ending. Patients who have worsening respiratory failure, will have acute lung injury that can progress to ARDS or acute respiratory distress syndrome. It's difficult to manage a postoperative lung resection with mechanical ventilation only because it causes ongoing injury to the lung tissue, and so there are some centers that will offer ECMO as a strategy of protecting the already injured along from ongoing injury from mechanical ventilation. Arrhythmia is another common complication associated with pre-operative management of lung cancer resection. Of the most commonly arrhythmia or supraventricular tachycardia is which are atrial fibrillation or atrial flutter. The postoperative rates are approximately five to 25 percent. So it's fairly common, it's rarely life-threatening, it does prolonged hospital stays. So it's a challenge in the setting of these cases. Patients who have increase chances of postoperative arrhythmia, are patients who are elderly, patients who previously have had atrial fibrillation or atrial flutter, patients who are undergoing extensive resections and patients with a history of congestive heart failure. Again, this prolongs hospital admissions for these patients and typically is associated with additional complications. These things combined will increase a patient's mortality. Patients who have these arrhythmia are approximately 15 percent of them are discharged with the arrhythmia. However, on follow-up less than two percent remain in this arrhythmia upto two to three weeks after discharge. Management of these patients afterwards typically includes beta-blockade and/or amiodarone to try to help control the rate or to keep the rhythm in sinus, and it's often necessary to anticoagulant these patients for a short period of time, meaning approximately three months. The myocardial infarction is also a risk for all these patients, postoperative myocardial infarction in this patient category is about 0.6 to 1.2 percent. It's associated with abnormal preoperative exercise testing and most importantly, it's associated with exercise testing that demonstrates reversible ischemia, which is myocardium that's at risk as a consequence of flow limiting coronary perfusion. The additional associations are intraoperative hypotension, so again careful interoperative management is necessary to conduct these operations and to help minimize postoperative associated complications. Patients who have significant coronary artery disease, should be treated prior to lung resection. Meaning, revascularization if it's needed is appropriate before undergoing an elective lung cancer operation. So this could require a coronary artery revascularization, with a surgical approach or it could require percutaneous coronary stunting by our cardiology colleagues. The stunting is important to recognize that coated stents typically require anti-platelet therapy for up to a year, and so partnering with your cardiology colleagues to help them understand that this is a strategy to get a patient to an elective operation within a month or two would help them choose uncoded or bare metal stunt which has minimal needs for platelet therapy, anti-platelet therapy. Then lastly a deep vein thrombosis and pulmonary emboli, are perioperative risks for patients. Postoperative DVT risk or rate is approximately 1-15 percent, postoperative PE is approximately 1.5 to 5 percent. In patients who are at risk for these complications are, cancer patients which is the topic today, but also patients who have limited mobility, who are actively smoking and who have advanced age. Patients undergoing a major surgical procedure are at increased risk as a consequence of the nature of the operation. These risks are all used to describe the kinds of patients we're talking about today, and if you look at the risks related to mobility as well as smoking, all these are controllable risk factors.. So again, attention to smoking cessation, as well as improving a patient's condition prior to surgery is an opportunity to minimize risks related to what can be a high risk operation. That brings us back to our what's now post-lecture question, over the years how have morbidity and mortality rates related to pulmonary resections changed? A. Mortality has decreased and morbidity is decreased, B. Mortality is increased and morbidity is increased, C. Mortality is unchanged while morbidity is decreased or D. Mortality has decreased and morbidity is remained unchanged and the answer is D. Mortality has decreased and morbidity has remained unchanged. So the take home points from this lecture: Complications can be minimized by appropriate patient selection, technical expertise, attentive to interoperative management and focused post operative care. Patient care is enhanced with a team of providers experienced with managing thoracic surgical patients. Thank you very much.
