Lung Cancer Patient Has Aortogenic Stroke After Sleeve Pneumonectomy - MedPage Today

A 70-year-old man presented to a hospital because he had been coughing up blood for about 6 months. He reported being a pack-a-day smoker for 50 years. Initial clinical assessment revealed that he had high blood pressure. He had not received any treatment with antiplatelet or anticoagulant agents.

Chest x-ray showed the presence of a mass in the right pulmonary hilum, and CT and PET-CT scans of his chest revealed a tumor in the pulmonary hilum with stenosis of the right upper lobe bronchus, with a standardized uptake value of 8.5. Calcification of half of the ascending aorta was also noted.

After subsequent bronchoscopy, the medical team noted a large area of redness and irregularity in the bronchial epithelium between the trachea and the lower lobe bronchus, along with narrowing of the right upper lobe bronchus. Clinicians performed a transbronchial biopsy of the lesion, and pathological assessment identified squamous cell carcinoma.

Results of additional biopsies from the lower trachea, one ring above the tracheobronchial angle and that of the B6/B7-10 spur, also supported a diagnosis of squamous cell carcinoma. However, ultrasound-guided transbronchial needle aspiration did not identify any malignant cells in the subcarinal lymph nodes.

Clinicians assessed the patient's lung function -- forced expiratory volume in 1 second was 2,850 mL (116.1% of the predicted value), and diffusing capacity of the lungs for carbon monoxide was 15.80 mL/minute/mm Hg (90.1% of the predicted value) -- and determined that the patient would not be able to tolerate surgical removal of the right lung.

Magnetic resonance imaging (MRI) of the patient's brain showed no evidence of metastasis or infarction. Staging was determined to be T4N0M0, and the patient was scheduled for a right sleeve pneumonectomy.

Surgeons performed the surgery using median sternotomy (MS), moving the ascending aorta repeatedly to access the tracheobronchial bifurcation.

The surgical process was described in the case report as follows: "Mediastinal lymph node dissection was performed, and the left main bronchus and the trachea were transected and anastomosed using 4-0 polydioxanone under ventilation through the operative field. A running suture in the membranous portion was performed with ventilation of the diseased lung to better expose the operative field. The cartilaginous portion was anastomosed with interrupted sutures after the endotracheal double-lumen tube was forwarded into the left main bronchus. Following the anastomosis, the right main pulmonary artery and right superior and inferior veins were stapled, the right lung was extirpated, and right sleeve pneumonectomy was performed."

Following surgery, the patient was extubated and moved to intensive care before he had fully regained consciousness. At that point, clinicians observed that the patient had mild paralysis affecting both arms.

The day after surgery, the patient underwent MRI of his head, which identified numerous areas of high intensity in the brain, most located in the cerebellum. However, subsequent magnetic resonance angiography of the head showed that the cerebral or vertebrobasilar arteries had not changed.

Echocardiography and contrast-enhanced CT also showed no evidence of cardiac thrombus, malformation, or valvular disease. Clinicians concluded that the patient had suffered a multiple embolic stroke -- likely a result of the need to move the ascending aorta numerous times during surgery to access the operative field for tracheobronchial anastomosis.

The patient was started on heparin therapy and the neuroprotective agent edaravone. Beginning 14 days after surgery, warfarin therapy was initiated, at a dose adjusted to a prothrombin time international normalized ratio of 1.5–2.5.

He received continuous anticoagulant therapy and rehabilitation for 2 weeks, and was discharged 30 days after surgery with no subsequent complications. The case authors reported that at 5 years after surgery, the patient was doing well and remained cancer-free.

Discussion

Clinicians presenting this case of a patient with lung cancer who developed a brain infarction following carinal resection with MS said they believe it to be the first report of multiple embolic stroke from the aorta, possibly associated with surgery after sleeve pneumonectomy.

The development of the stroke immediately following surgery raises the possibility that it was due to repeated mobilization of the ascending aorta, which is necessary to allow surgical access to the operative field, the authors explained.

They noted that sleeve pneumonectomy is used for extensive tumor resection involving the tracheobronchial angle, carina, or lower trachea. Right sleeve pneumonectomy is usually performed using a right posterolateral thoracotomy in the fifth intercostal space; on the other hand, MS allows ventilation of the diseased lung.

Advantages of the MS approach include less incisional pain, and postoperatively less ventilatory restriction, the authors observed, cautioning that the decision to use either a posterolateral thoracotomy or MS approach requires careful consideration of the advantages and disadvantages.

Analysis of 801 surgeries recorded in a patient registry to determine whether MS is an equivalent incision to thoracotomy in the treatment of primary pulmonary carcinoma found nonsignificant differences favoring thoracotomy for operative mortality, postoperative complications, and similar rates of long-term survival. However, mean postoperative length of stay for MS lobectomy was 7.5 days compared with 8.5 days for thoracotomy (P=0.06).

"Median sternotomy provides more complete staging, shorter postoperative hospitalization, and better patient acceptance with equivalent operative and when compared with thoracotomy. Concerns regarding increased wound infections in MS patients appear unfounded," the authors of the analysis concluded.

The case authors said that although most surgeons prefer posterolateral thoracotomy, the MS approach has several advantages, including less post-surgical incisional pain, and in some patients, ventilation of the diseased lung, which "may reduce the difficulty in achieving anastomosis under intubation of the left main bronchus."

Nevertheless, the team cautioned, MS requires repeated mobilization of the ascending aorta to allow surgical access for airway anastomosis. This can result in aortic plaque flowing into the arteries of the brain, causing multiple embolic strokes -- mainly cerebellar infarction, which may be attributed to surgery-associated embolism.

The case authors cited a study suggesting a 1.29-1.7% prevalence of pulmonary embolization and thrombosis of the superior vena cava, a postoperative complication of carinal resection. Their own patient's case is notably rare, since there have been no reports of postoperative embolic stroke associated with the MS approach, the case authors said.

The patient had all three MRI findings that were characteristic of aortogenic embolic stroke: ≥ 3 lesions, lesions with a maximum diameter of < 30 mm, and vertebrobasilar system lesions. Furthermore, aortic arch calcification on chest radiography and aortogenic brain embolism have been linked in other research.

The patient's preoperative CT demonstrated semicircular calcification of the ascending aorta. "It is suggested that atherosclerotic plaques ≥ 4 mm in thickness, ulcerated aortic plaques, and mobile aortic plaques in transesophageal echocardiography (TEE) are risk factors for ischemic stroke," the case authors wrote.

They cited a study showing that in patients with stroke, and especially cryptogenic stroke, the 2-year incidence of recurrent stroke or death progressively increased with arch plaque size, from 10.1% in patients with no plaque, to 16.5% in patients with small plaque, and to 26.7% in those with large plaque.

The case authors said that given the risk of embolic stroke by mobilization of the aorta, use of TEE in cases of aortic calcification may help inform the choice of approach for sleeve pneumonectomy. Their patient "did not develop sequelae associated with multiple embolic stroke, and has been well for 5 years after surgery," the team wrote. "However, it is important to consider the presence of aortic calcification when choosing the appropriate approach for sleeve pneumonectomy."

Conclusion

The authors concluded that since aortogenic embolic stroke can occur after sleeve pneumonectomy with MS, the possibility of aortogenic embolic stroke caused by repeated mobilization of the aorta should be considered when calcification of the ascending aorta is observed on preoperative CT.

Last Updated November 16, 2021

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  Kate Kneisel is a freelance medical journalist based in Belleville, Ontario.

Disclosures

The case report authors declared that they have no competing interests.