What is the optimum strategy for thromboembolic prophylaxis following extrapleural pneumonectomy in patients with malignant pleural mesothelioma?

Our plain-English summary of What is the optimum strategy for thromboembolic prophylaxis following extrapleural pneumonectomy in patients with malignant pleural mesothelioma?, by A. Billè, L. Okiror, W. Karenovics, et al (Interactive Cardiovascular and Thoracic Surgery, 2012).

The study

• Authors: A. Billè, L. Okiror, W. Karenovics, J. Pilling, L. Lang-Lazdunski
• Journal: Interactive Cardiovascular and Thoracic Surgery
• Published: 2012;15(2):201-3
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) increases the risk of venous thromboembolic (VTE) events. This risk is higher following extrapleural pneumonectomy (EPP) as part of trimodality therapy, where VTE can be catastrophic. In our series, the impact of warfarin in preventing a pulmonary embolus (PE) after neoadjuvant chemotherapy and EPP for MPM was analysed. A retrospective analysis of 21 consecutive patients undergoing EPP for MPM was conducted. The first 10 patients (Group A) had VTE prophylaxis by subcutaneous enoxaparin and compression stockings commenced a day prior to surgery, intraoperative pneumatic calf compression and early post-operative mobilization. Enoxaparin was continued for 30 days postoperatively. The following 11 patients (Group B) had the same VTE prophylaxis, together with warfarin, started prior to hospital discharge and continued for 6 months postoperatively. All patients had a computed tomography pulmonary angiogram within 8 weeks after surgery and a full examination at 1, 3, 6 and 12 months. Both groups were comparable for characteristics. Three patients in Group A suffered a PE at 4, 6 and 16 weeks postoperatively. One PE was fatal. No patient in Group B suffered VTE (P = 0.05, χ(2) test) or haemorrhagic complications. Warfarin anticoagulation following EPP is feasible and safe, and is associated with a significant reduction in VTE complications.

In plain English

This study, which did not examine asbestos exposure, looked at preventing blood clots after extrapleural pneumonectomy, a major operation for malignant pleural mesothelioma. The authors reviewed records of 21 consecutive patients treated at one surgical practice from April 2004 to May 2008. All received standard clot prevention, including enoxaparin injections planned for 30 days after surgery. The first 10 (Group A) received only this. The next 11 (Group B) also took warfarin for 6 months, and their enoxaparin stopped once their INR (a clotting test) exceeded 2.0. Three Group A patients had a pulmonary embolus (a clot in the lung), at 4 weeks, 6 weeks and 4 months; one was fatal. No Group B patient had a clot. The text gives P = 0.05 for this difference, but a table gives P = 0.09. The authors reported no clinically significant bleeding in either group, but a complications table lists 2 in-hospital re-operations for bleeding without explaining this. They concluded that 6 months of warfarin may reduce clot risk without significant bleeding risk. They cautioned that the study was small and retrospective, so drawing conclusions may not be appropriate.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective review of a consecutive series of patients at a single centre, comparing an earlier group (no warfarin) with a later group (warfarin); patients were not randomized
• Who was studied: 21 consecutive patients with malignant pleural mesothelioma (epithelioid or biphasic subtype) who underwent extrapleural pneumonectomy after neoadjuvant chemotherapy between April 2004 and May 2008. They were treated at a single thoracic surgical practice; the authors' department is at Guy's & St Thomas', London. 25 patients were considered: 3 had exploratory thoracotomy only and 1 died during surgery. Median age was 62 (range 52 to 68), and 19 (90%) were male. Group A n = 10, Group B n = 11.
• Exposure: Asbestos exposure was not studied; the comparison was of clot prevention methods. All patients received enoxaparin 40 mg under the skin, intended to continue for 30 days after surgery. They also received compression stockings, calf compression during surgery and early mobilization. Group B also received warfarin, started before discharge and continued for 6 months, with a target INR of 2.0 to 2.5. Group B's enoxaparin was discontinued once INR was above 2.0.
• Main results:
  • In Group A (no warfarin, n = 10), 3 patients had a pulmonary embolus, at 4 weeks, 6 weeks and 4 months after surgery; one was fatal.
  • In Group B (warfarin, n = 11), no patient had a venous thromboembolic event; the text reports P = 0.05.
  • Table 1 lists thromboembolic complications as 3 (no warfarin) versus 0 (warfarin), with P = 0.09.
  • The results text states that no patient in either group had a clinically significant haemorrhagic (bleeding) event.
  • Table 2 (in-hospital complications after surgery, all 21 patients) lists 2 re-operations for bleeding. The article does not say which group these patients were in or how this fits with the no-bleeding statement.
  • One Group B patient's INR reached 6.0 during radiotherapy after right-sided surgery, without a bleeding complication.
• The authors' conclusion: The authors concluded that 6 months of warfarin after extrapleural pneumonectomy may reduce the risk of venous thromboembolism, with no significant risk of bleeding. They also said they believe it may potentially prevent a catastrophic pulmonary embolism and is safe and easy to manage.
• Limitations the authors state:
  • The authors stated that the study was small and retrospective with a limited number of patients, so it carries a potential bias. They added that drawing conclusions or making recommendations may not be appropriate.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Extrapleural Pneumonectomy (EPP), Pleural Mesothelioma, Trimodality Therapy, Neoadjuvant Chemotherapy.

Related studies

• Induction chemotherapy, extrapleural pneumonectomy, and adjuvant radiotherapy for malignant pleural mesothelioma: experience of Guy's and St Thomas' hospitals — A. Bille, E. Belcher, et al. (2012)
• Staging of patients after extrapleural pneumonectomy for malignant pleural mesothelioma--institutional review and current update — C. Cao, S.K. Krog Andvik, et al. (2011)
• Accelerated hemithoracic radiation followed by extrapleural pneumonectomy for malignant pleural mesothelioma — M. de Perrot, R. Feld, et al. (2016)
• Trimodality strategy for treating malignant pleural mesothelioma: results of a feasibility study of induction pemetrexed plus cisplatin followed by extrapleural pneumonectomy and postoperative hemithoracic radiation (Japan Mesothelioma Interest Group 0601 Trial) — S. Hasegawa, M. Okada, et al. (2016)
• Clinical and pathological features of three-year survivors of malignant pleural mesothelioma following extrapleural pneumonectomy — D.J. Sugarbaker, A.S. Wolf, et al. (2011)
• Intrathoracic chemo-thermotherapy with radiofrequency waves after extrapleural pneumonectomy for malignant pleural mesothelioma — T. Tokunaga, M. Higashiyama, et al. (2011)

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