Bland or tumor pulmonary artery stump thrombosis?

Frequency and Predictors of Pulmonary Arterial Stump Thrombosis following Pneumonectomy or Lobectomy

OBJECTIVES

Pulmonary artery stump thrombosis (PAST) following pneumonectomies/lobectomies is rare; its clinical importance is unknown. The objectives of this study were to analyze the prevalence and risk factors of PAST and the clinical significance in patients with pneumonectomy/lobectomy.

METHODS

All adult cases who underwent pneumonectomy/lobectomy in our hospital for any reason and who underwent control contrast-enhanced thoracic CT during the follow-up period were included in the study. Demographic and clinical features of the patients, data on surgery, and the features of thrombi were recorded.

RESULTS

During the 4-year study period, a total of 454 patients underwent pneumonectomy/lobectomy (93 pneumonectomy and 361 lobectomy). Among the patients, 202 patients (50 pneumonectomy and 152 lobectomy) with at least one follow-up thorax CT were included in the analyses. PAST was detected in 9 (4.5%) of 202 patients and mostly seen in patients with pneumonectomy (lobectomy: 2.6% vs. pneumonectomy: 10%, p = 0.043) and in patients whose pulmonary artery was ligated by using stapler (suture ligation 1% vs. stapler: 7.4%, p = 0.034). Pulmonary artery stump was also longer in patients with PAST (8.48 ± 11.22 mm vs. 23.55 ± 11.22 mm, p < 0.001). Univariate logistic regression analysis showed that pneumonectomy and longer pulmonary artery stump length were found to be significantly associated with PAST (p = 0.041 and p = 0.001, respectively).

CONCLUSIONS

PAST was detected in 4.5% of our subjects undergoing lobectomy/pneumonectomy. PAST was found to be significantly higher in subjects who underwent pneumonectomy, those with longer pulmonary artery stump, and those with pulmonary artery stump ligated by using stapler.

Pulmonary Artery Stump Thrombosis: To Treat or Not to Treat? The Question Is Still Open. Description of a Case and Review of the Literature

Pulmonary artery stump thrombosis (PAST) represents a possible complication after lung surgery. We report the case of a 59-year-old man who presented with dyspnoea about 4 years after right pneumonectomy due to squamous cell lung cancer. A CT-scan showed the presence of pulmonary artery stump thrombosis. Although there was no evidence of pulmonary embolism, given the clinical features and radiological shape of the thrombus, anticoagulation treatment with low-molecular-weight heparin was started with improvement of symptoms. The patient was discharged on anticoagulant treatment and a pulmonary CT-scan performed 4 months later showed an almost complete resolution of the PAST. Pathophysiological mechanisms of PAST are still unknown, although several hypotheses have been proposed. However, the decision to treat PAST with anticoagulants is still controversial. A review of literature will be provided in order to discuss risk factors, possible etiologies and to highlight clinical and radiological characteristics that could suggest to treat this condition, in particular when there is an increased risk of complications.