Concomitant Cardiac and Pulmonary Operations



Concomitant Cardiac and Pulmonary Operations


Aart Brutel de la Rivière



A simultaneous operation on the heart and lungs through one incision remains controversial.11 The main arguments for concomitant surgery16 are less discomfort for the patient (one incision, one hospital stay, less pain) and probably a better outcome in the long term owing to decreased trauma, as proposed for VATS lobectomy.27 If a staged approach must be chosen, the interval between the two operations should be dictated by the sequence, and types of procedures to be used. When the cardiac procedure precedes the lung resection, wound healing should be complete and the patient should have recovered fully so as to be able to tolerate a second major thoracic intervention. Off-pump cardiac surgery still requires sternotomy, but the detrimental effects of cardiopulmonary bypass (CPB) are avoided, thus shortening convalescence.20 In most cases the interval will be at least 6 weeks to allow for proper sternal healing. If, on the other hand, the lung resection is done first and a minimally invasive approach is taken (i.e., lung resection by VATS), open heart surgery may follow in a few weeks.

The spectrum of these interventions ranges from a major cardiac operation and the clipping of some bullae to the use of CPB during the resection of a malignant tumor invading the heart.

The planned use of bypass as an adjunct in the treatment of locally advanced thoracic malignancies3,5,8 is not discussed in this chapter; neither is the emergency use of CPB during lung surgery (e.g., in carinal resection to ensure oxygenation).15 On the other hand, cardiac operations without bypass—so-called off-pump procedures—are discussed, as some authors claim the nonuse of extracorporeal circulation to be advantageous, particularly in the setting of combined procedures.9,19 Moreover, off-pump techniques have contributed to technical advancements that may be helpful during combined operations. On the other hand, video-assisted pulmonary resections have obviated the need for large incisions and thus may contribute, in their way, to the treatment options in these complex cases.12 Leaving either of the two pathologies untreated will result in inferior outcomes.7,24

The focus of this chapter is on the treatment of both lung cancer and cardiac pathology requiring intervention.


Presentation

Patients may present with cardiac pathology and subsequently prove to have a lung tumor, or they may be found to have heart disease during the workup of lung cancer.

As for the heart, a clear distinction should be made between coronary and noncoronary pathology. The latter, mostly valvular heart disease, will require open heart surgery (i.e., on-pump, which means using CPB). It is the use of the pump that introduces detrimental variables such as the systemic inflammatory response syndrome (SIRS) and coagulation disorders. It will increase the extra- and intracellular water content as well as pulmonary capillary permeability.

Coronary artery disease may also be treated by a percutaneous coronary intervention (PCI), avoiding surgery altogether. Today, during many PCIs, a stent is left inside the coronary arteries to improve long-term results. However, modern stents, especially drug-eluting stents (DESs), will require the long-term use of potent platelet-inhibiting drugs (such as clopidogrel [Plavix]), the discontinuation of which can lead to serious adverse outcomes due to in-stent thrombosis. Therefore this strategy has been abandoned in the subset of patients discussed here, particularly as operating in a platelet-depleted milieu will increase bleeding complications.

The surgical approach to the heart is virtually always through median sternotomy. In many cases this is adequate for pulmonary resection but limits the exposure for systematic lymph node dissection. As for the pulmonary pathology, the complete right lung is easily approachable from the midline. However, the left lower lobe—particularly in cases of an enlarged, or severely hypertrophic left ventricle—is less accessible.

Operating on patients in a combined setting should achieve the same therapeutic goals as in standard lung surgery (i.e., complete anatomic resection and systematic nodal dissection).

Although the definition of systematic nodal dissection varies, it will include lymph node extirpation in the pulmonary ligament, the hilum, and the superior mediastinum and, on the left side, nodes close to the great vessels. Also, it will include removal of nodal tissue in the main carina (Naruke’s station 7), which is straightforward in the median sternotomy setting
through the posterior pericardium, behind the aorta. However, removal of superior mediastinal nodes, as well as removal of nodes in the pulmonary ligament on the left side, will be quite cumbersome. If, after surgery, uncertainty remains as to the completeness of the nodal dissection, postoperative chemotherapy should be considered.

When patients undergo simultaneous surgery for both lung cancer and cardiac pathology, it may be preferable to remove the malignant process first. Although the use of CPB never was circumstantially shown to enhance tumor growth, there is evidence that the immune system is jeopardized.

Hemodynamic stability will dictate the intraoperative strategy (i.e., the sequence of interventions), which may include: resection of the lung tumor prior to the cardiac procedure, without cardiopulmonary bypass (and thus avoiding full heparinization); or, if necessary on bypass (which will require full heparinization); or after cardiac repair, being on bypass; or, finally, after discontinuation of CPB (and thus, after neutralization of heparin). In off-pump cases, the sequence options is essentially the same.


Indications and Contraindications


Heart

The indications for cardiac surgery have been formulated by the American Heart Association (www.aha.org). A complete preoperative workup should pay special attention to cardiac reserve; in case of valvular pathology, right heart catheterization may be useful.

Risks may be assessed using risk-stratification models, although they are known to be unreliable in the higher-risk zones. As the risk of a combined operation is slightly higher than the risk of cardiac surgery by itself, attention should be paid to incremental risk factors for death involved in the operation at hand. Particularly in patients where pneumonectomy is anticipated, the changes in circulatory physiology by the removal of one lung should be taken into account. Absolute contraindications include poor lung function and renal insufficiency, the latter being defined by a plasma creatinine >200 μmol/L. Age as a number by itself never quantifies surgical risk; on the other hand, age as a reflection of the organism’s total biological reserve (“age as a value”) is one of the strongest risk factors in cardiac surgery. Poor left ventricular function and a diminished life span will preclude this approach; that is, the lung tumor will have to be irradiated. Emergent combined surgery does not seem to be indicated: cardiac salvage will have priority.


Lung

The indication for surgery in patients with lung cancer needing a cardiac intervention may be different, to the extent that these patients will have to undergo an operation anyway, thus waiving treatment modalities such as chemoradiotherapy as the primary strategy to cure. Bilateral pathology is not a contraindication to a combined operation. The contraindications to a simultaneous procedure are the anticipation of either severe bleeding complications or technical difficulties in removing the tumor completely. Examples of the first are extensive pleural adhesions and chest wall involvement; these contraindications are considered absolute. Technical problems may be anticipated in left-lower-lobe tumors, although special technical maneuvers will allow safe resection in most cases. If a pneumonectomy is indicated, special attention should be paid to the patient’s reserves, as there is always increased morbidity and mortality with pneumonectomy alone.

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Jun 25, 2016 | Posted by in RESPIRATORY | Comments Off on Concomitant Cardiac and Pulmonary Operations

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