Surgical management of a simultaneous aortic valve replacement and pneumonectomy

Abstract

Combined heart surgery and lung resection remains a controversial issue. The treatment of two major conditions in the same operative time may be attempted in certain cases. We report the case of a 68-year-old man who presented for dyspnea on exertion. The chest computerized tomography scan showed an infiltrating tumor which involved the right interlobar artery. A pneumonectomy was indicated and the preoperative echocardiography detected a calcified aortic valve with severe stenosis and significant pressure gradient. The patient had combined pneumonectomy and aortic valve replacement through median sternotomy and was discharged 18 days after surgery. Cardiac valve replacement is feasible in conjunction with pulmonary resection. However morbidity is increased in case of associated pneumonectomy.

Introduction

The management of patients with lung cancer and concomitant valvular heart disease is often problematic. The coexistence of both conditions, although rare, reported in only 0.5% of cardiac surgical cases [1], raises many challenges for the therapeutic strategy. Due to the interactions between the cardiac performance and the pulmonary function, the coexistence of any heart disease is considered as a high morbidity and mortality risk factor, whenever an anatomic pulmonary resection is warranted. Because of population aging, patients present often with associated comorbidities, which have to be considered for surgical management [2]. However, the timing and the therapeutic strategy for valvular heart diseases associated with lung cancer are not consensual. We present herein the case of a patient presenting for a pulmonary neoplasm associated with aortic valve stenosis, which required both surgical management and were operated at the same time.

Case report

A 68-year-old man, presented to our surgical unit for a persistent dry cough associated with dyspnea on exertion. He was a former smoker and reported no past medical comorbidities. Physical examination revealed a midsystolic crescendo-decrescendo ejection murmur in the right second intercostal space. He was in regular rhythm with 80 bpm, his blood pressure was 130/70 mmHg and peripheral capillary oxygen saturation (SpO2) was 98% on room air. Electrocardiogram showed a normal sinus rhythm with normal axis and normal T-wave. Chest X-ray showed a right-hilar non-homogeneous opacity and contrast-enhanced computerized tomography (CT) scan showed a right-hilar lesion bulging into the right pulmonary artery (Fig.1). Fiberoptic bronchoscopy was normal. So the tumor was classified as cT4 (right pulmonary artery involvement) N0 M0 (no distant metastases at the CT). In order to rule out the presence of a thrombus in the right pulmonary artery and to ascertain the degree of its involvement, a chest magnetic resonance imaging (MRI) was performed. It showed an infiltrative neoplastic lesion of 26 × 18 mm in great axes, located in the fissure. The tumor involved the right interlobar artery, was bulging into its lumen and extending to the right inferior lobar artery. The lesion was hypersignal on T1 and diffusion-weighted images, slightly hypersignal, and heterogeneous on T2-weighted images and enhanced after gadolinium injection (Fig.2). Transthoracic echocardiogram showed a calcific aortic valve stenosis, with mean pressure gradient of 34 mmHg and an aortic jet velocity of 4 m/s, without left ventricular dysfunction. Coronary angiography was normal. Laboratory tests were within normal limits.

Fig. 1.

The right-hilar lesion bulging into the right pulmonary artery at chest CT; a axial CT image in lung window, b axial CT image in mediastinal window, c coronal, and d sagittal CT images in mediastinal window

Fig. 2.

MRI image showing tumorous infiltration (Tm) in the right interlobar artery (red arrow)

The case was discussed at our weekly hospital tumor board review, at the weekly heart team meeting with cardiologists and with our anesthesia team.

The aortic valve stenosis was judged severe and prompted aortic valve replacement. The neoplastic lesion was of an unknown origin and was extending through the right pulmonary artery lumen. CT-guided transthoracic lung biopsy was judged at high risk of bleeding and was not possible. Therefore, we decided to treat both conditions at the same operative time in order to avoid delay in surgical management.

Under general anesthesia and selective intubation, through median sternotomy, we proceeded first with right pneumonectomy. The right pleura was opened and some adherences were freed. The right hilum was dissected and the pulmonary artery was controlled near to the mediastinal artery. Because of the proximity of the tumor, we opened the pericardium and the main right pulmonary artery was dissected, controlled, and cross-clamped between the superior vena cava and the aorta. It was sectioned and sutured with polypropylene monofilament 5/0. The superior and inferior pulmonary veins were also dissected, sectioned, and sutured. The right main bronchus was dissected. Section and suture were performed using automatic staplers (Fig.3). Subcarinal lymph nodes were dissected and a specimen sent for frozen section, was negative. Hemostasis was carefully controlled and then we proceeded with valve replacement.

Fig. 3.

Image of the resected right lung: a centered image showing the tumor bulging into the pulmonary artery lumen and the closed bronchial stump above

Cardiopulmonary bypass (CPB) was established between the right atrium and the ascending aorta, with anterograde cardioplegia. The heart was vented by the ascendant aorta and through the right superior pulmonary vein. When full flow on moderate hypothermia was achieved, the heart was arrested after a first cardioplegic dose. Perioperative myocardial protection was achieved using an anterograde intermittent cold blood cardioplegia. Aortic valve was replaced by a mechanical prosthesis. Weaning from CPB was easy, with no need for vasoactive drugs. Cross-clamping time was 50 min and CPB time was 90 min. At the end of the procedure, two chest tubes were placed in the mediastinum, with one into the posterior pericardium and the other in front of the pericardium after its partial closure. Controlled mild suction was applied to both of them. The right pleural cavity was drained with one chest tube underwater seal without suction.

The postoperative fluid management was based on fluid restriction. Total postoperative intravenous infusion volume within 24 h was < 1500 ml. Resuscitation endpoints were mean arterial pressure (MAP) at or above 60 mmHg, urinary output more than 0.5 ml/kg/h, SpO₂ at or above 92%, hemoglobin level at or above 8.0 g/dl and central venous oxygen saturation (ScvO₂) at or above 70%. If hypotension appeared or urine volume was < 0.5 ml/kg/h, vasoconstrictors were used guided by echocardiography.

The patient was extubated 2 hours postoperatively. His hemodynamic status was stable without vasoactive drug support. Heparin therapy was introduced at the sixth hour postoperatively. Transfusion of packed red blood cells and fresh-frozen plasma was needed, because of postoperative low hemoglobin level and prolonged prothrombin time. Postoperative chest X-ray showed a mediastinal shift, which needed often to be balanced in order to avoid cardiac arrhythmia. The mediastinal tubes were removed at the second postoperative day. The right chest tube was removed at the third day. Pericardial pacing wires were removed at the fourth day and the switch from intravenous heparin to oral warfarin was started 5 days postoperatively.

At the fifth postoperative day, the patient developed dyspnea with hypoxemia and oxygen therapy dependence. A pulmonary embolism or right-to-left interatrial shunt was suspected. Postoperative transthoracic echocardiogram showed a good hemodynamic profile of the aortic prosthesis, no dilatation of cardiac chambers, no right-to-left shunt, and a left ventricular ejection fraction of 60%. Contrast-enhanced CT scan showed an atelectasis in the left lower lobe and no pulmonary embolism. The patient recovered after non-invasive ventilation sessions and was discharged 18 days after surgery.

Pathological study revealed a sarcomatoïd carcinoma, which involved the pulmonary artery and developed under the intimal layer, without endoluminal extension. The bronchial and vascular stamps were free from tumor and the dissected lymph nodes were negative. According to the seventh edition of the TNM staging, the tumor was classified as pT4 N0 M0, stage IIIA. The patient was referred to pulmonary medicine department for further management and surveillance.

Discussion

The case of our patient illustrates an uncommon situation, which has been formerly reported in literature. In patients with coexisting cardiac disease and lung lesion, postoperative mortality following lung resection is significantly increased [2]. Performing the cardiac surgery before the pulmonary resection, in a staged procedure, reduces the postoperative morbidity and mortality [2, 3]. A recent meta-analytic study on the management and postoperative outcomes in primary lung cancer and heart disease, showed that combined surgical operations were significantly (P < 0.001) correlated with higher postoperative complications [2]. In the same meta-analysis, postoperative proportions of complications were significantly higher in case of lobectomy for squamous lung carcinoma (P = 0.001) and p-T1 (P = 0.002), or p-T2 (P = 0.034). Use of CPB did not significantly impact the rate of postoperative complications (P = 0.580) or the three (P = 0.121), and five-year survival (P = 0.726).

Five-year survival was significantly decreased in case of higher rates of lobectomy (P = 0.009) and mean age (P = 0.046).

Although operative mortality in patients with coexisting lung cancer undergoing CPB may be significantly increased, with higher risk of postoperative complications, especially in case of associated pneumonectomy, delaying lung resection would result in tumor growth and dissemination [2]. In addition, a deficient immune response, sustained during CPB at the time of cardiac surgery may favor this process [4]. As a result, the lung tumor which was at first resectable could become unsuitable for surgery and the chances of patient recovery hindered. In our patient, the tumor was highly suggestive of malignancy. We did not have the possibility to ascertain the diagnosis with a preoperative biopsy. In addition, it involved the pulmonary artery through the fissure and no less than a pneumonectomy could have achieved total removal of the tumor with satisfactory oncologic results.

A staged procedure has also other drawbacks: the morbidity and cost of two separate operations. A single combined procedure may be preferred to avoid repeated anesthesia. However, it should be well studied and prepared because perioperative cardiac complications are higher in case of simultaneous surgery for aortic valve stenosis and lung resection [5].

In our case, we decided a combined surgery because of the presence of an advanced tumor and severe aortic valve stenosis. A two-staged procedure was really risky. The perioperative management of pneumonectomy first, could be difficult because of the aortic valve stenosis. Performing pneumonectomy in a patient with a mechanical valvular prosthesis could be at high risk of complications. Papers dealing with simultaneous lung resection (especially pneumonectomy) and aortic valve replacement are very scarce.

In a meta-analysis, which reviewed the relevant published papers between 1980 and 2015, coronary artery bypass grafting (CABG) performed at the same time with resection of lung cancer was significantly higher compared to both aortic valve replacement (AVR) (P = 0.001, 14 studies) and mitral valve replacement (MVR) (P = 0.012, 8 studies). AVR and MVR frequency was similar (P = 0.899, six studies) [2].

Median sternotomy is the preferred approach for combined heart and lung surgery. It is associated with less pain, reduced analgesic requirements, faster recovery of pulmonary function, and fewer pulmonary complications, even in patients with impaired pulmonary function and decreased pulmonary reserve [5]. Regarding the operative strategy, lung resection is preferably performed first, before CPB establishment. With this strategy, lung resection is performed with efficient coagulation and duration of CPB is shortened. Many authors share our opinion [4] and prefer to begin with pulmonary resection to avoid spreading of tumor cells by CPB, or bleeding after heparin administration. The use of CPB during lung resection through median sternotomy can facilitate the anatomical resection, especially for the left lower lobe, with safe forward luxation of the heart and better exposure [6].

In patients undergoing valve operations, Todd et al. [7] prefer to resect the pulmonary lesion after closure of the pericardium, to avoid contamination by respiratory pathogens, due to the presence of a transected airway. In our case, we had to control the artery in the pericardium. Besides, the bronchus was sectioned and sutured with a mechanical stapler. Therefore, there were no communications between the airways and the operative field at any moment of the surgery.

However, Wu et al. [8] stated that CPB can spread the tumor cells and cause a serious systemic reaction, with rapid hematogenous dissemination. It may cause transient suppression of the immune system, which makes the metastatic process easier.

Sternotomy is a less comfortable approach to perform lung resection and mediastinal lymphadenectomy, because of the difficult access to the posterior mediastinum [5]. In our case, subcarinal lymph nodes were negative at frozen section and were not required to perform any lymph node dissection.

Patients, who have undergone pulmonary resection, often complain of dyspnea, which is frequently explained by the loss of alveolar volume and restriction of the pulmonary vascular bed. Moreover, postoperative pain due to sternotomy, diaphragmatic stunning, inflammatory syndrome secondary to CPB, transfusion, and atelectasis, hinder the gas exchange, such as in our patient.

Obliteration of post-pneumonectomy space, usually takes 3 weeks to 7 months [9] and particularly in the presence of mediastinal distortion, a right-to-left shunt may develop despite normal right atrial pressure [10]. This complication was eliminated in our case by echocardiography. Mediastinal distortion was worsened in our case because of the mediastinal tubes. In spite of our attempts to avoid communication between the mediastinal tubes and the pleural cavity and the mild suction applied to the mediastinal compartment, the post-pneumonectomy pleural cavity was partially aspirated. This altered the intra-thoracic equilibrium between the two compartments and required restoration of mediastinal balance many times before chest tube removal.

Conclusion

Combined treatment of cardiac disease and lung cancer seems to be feasible and safe with good results. It can be carried out with accepted mortality and morbidity. However, this morbidity is increased in case of associated pneumonectomy. It may be a good alternative for selected patients, with economic benefits. Median sternotomy is currently the standard approach, which enables a comfortable cardiac intervention as well as an adequate access to almost all lung segments. If using of CPB is necessary, lung resection is better performed before CPB establishment, if the location of the malignancy does not require resection under CPB.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Informed consent

For this type of study, formal consent is not required.