A survey on pulmonary thromboendarterectomy in the Asia-Pacific region

Abstract

Background

Surgical pulmonary thromboendarterectomy has been established as the treatment of choice for chronic thromboembolic pulmonary hypertension. We conducted a survey among Asia-Pacific cardiothoracic surgeons to examine their current practice demographics and reflect their views on the future prospects for pulmonary thromboendarterectomy surgery.

Methods

All cardiothoracic surgeons who were registered on the CTSNet.org website and based in the Asia-Pacific region were invited to participate in an online survey. The electronic questionnaire was completed by 172 (6.3%) surgeons. Responses were recorded anonymously and tabularized as absolute figures and fractions.

Results

Pulmonary thromboendarterectomy surgery has been performed by few Asia-Pacific surgeons and in small numbers of patients, but survival rates and functional outcomes were satisfactory in most experiences. Failures were thought to have resulted primarily from the difficulty in selecting suitable candidates for surgery. The need for greater clinical experience was clear, yet this might be hampered by the limited recognition of pulmonary thromboendarterectomy surgery as a potential cure for chronic thromboembolic pulmonary hypertension. Most surgeons considered that this procedure should be restricted to designated expert centers, and acknowledged the need to organize dedicated regional meetings where clinical practice guidelines can be established and updated as appropriate for regional healthcare facilities.

Conclusions

Although much effort is needed before pulmonary thromboendarterectomy surgery becomes widely adopted in the Asia-Pacific region, many surgeons and centers are already seeking its implementation. Designating expert centers, bringing together a regional working group on pulmonary thromboendarterectomy, and establishing clinical practice guidelines as appropriate for regional healthcare facilities were recommended.

Keywords

Endarterectomy Hypertension pulmonary Pulmonary artery Surveys and questionnaires Thromboembolism

Introduction

Surgical pulmonary thromboendarterectomy (PEA) is presently considered the first choice of treatment for chronic thromboembolic pulmonary hypertension (CTEPH) due to its established efficacy in improving patient prognosis and the limited availability of alternative treatment modalities.^1–4 Wider implementation of PEA surgery in regions such as the Asia-Pacific is likely to have a significant medical and economic impact, given that around 60% of the entire world population reside in this region, and that the incidence of new CTEPH cases in the Asia-Pacific region is likely to exceed 50,000 per year.^5,6 We sought to examine and poll, directly and anonymously, Asia-Pacific cardiothoracic surgeons who are interested in PEA surgery to determine their current demographics and practice and to reflect their opinions on future practice and how wider adoption of this operation might be enhanced.

Methods

Between November 2015 and March 2016, invitations to participate in an online survey were emailed to all cardiothoracic surgeons who were registered on the CTSNet.org website and based in the Asia-Pacific region (n = 2745). Responses were recorded anonymously, and tabularized as absolute figures and fractions. This article presents their responses to the most pertinent questions (Table 1).

Table 1.

Summary of survey questions.

1. In what type of setting do you practice?

(a) academic institution

(b) government institution

2. What is your institution’s annual workload?

(a) up to 200 cardiac operations/year

(b) 200–500 cardiac operations/year

(d) more than 1000 cardiac operations/year

3. Are heart/lung transplantation services available in your institution?

(a) yes

(b) no

4. Are ECMO or LVAD services available in your institution?

(a) yes

(b) no

5. Are PEA operations performed in your institution?

(a) yes

(b) no

6. State your years of experience in post-training practice.

(a) up to 5 years

(b) 5–10 years

7. What is your personal annual workload?

(a) up to 100 cardiac operations/year

(b) 100–200 cardiac operations/year

8. Are you personally familiar with the PEA operation?

(a) not at present

(b) only theoretically through the literature

(d) I have personally performed the operation

9. How many PEA operations have you personally performed?

10. What was the overall functional outcome in your experience?

(a) no improvement whatsoever

(b) mild-to-moderate improvement

(d) other, please specify

11. What was the perioperative mortality rate in your experience? Please specify.

12. In your experience, what were the main difficulties in performing PEA operations?

(a) selecting suitable candidates

(b) the technically demanding technique

(d) other, please specify

13. In your opinion, what could indicate inoperability in a given patient?

(a) presence of distal vessel occlusions

(b) presence of severe RV failure

(d) presence of comorbid conditions

(e) mismatch between hemodynamics and extent of occlusions

14. In view of your experience, do you intend to perform PEA surgery within the next 5 years?

(a) I have not done it, but I intend to

(b) I have not done it, and do not intend to

(d) I have done it, but will never do more

(e) I am not sure

15. If you intend to perform PEA operations, how many patients in your own unit could be candidates for surgery every year? Please specify.

16. What might be your reasons for NOT performing PEA surgery?

(a) I do not believe in this intervention

(b) suitable patients are not available

(d) other, please specify

17. Do you consider that this procedure should be restricted to dedicated teams in certain institutions?

(a) yes

(b) no

18. Do you consider that the availability of ECMO/LVAD or heart/lung transplantation backup necessary?

(a) yes

(b) no

19. Do you consider that attending a live demonstration is necessary before embarking on the operation?

(a) yes

(b) no

20. Do you believe that colleagues with relevant experience should be available to advise early in the learning curve?

(a) yes

(b) no

21. In your opinion, what are the present limitations to wider adoption of the PEA operation?

(a) lack of recognition of the condition and of the possibility of surgical cure

(b) indications for surgery are not yet clear

(d) mortality/morbidity rates are unacceptably high

(d) other, please specify

22. Do you believe that the number of PEA operations performed in the Asia-Pacific region will increase in the next 5 years?

(a) yes

(b) no

(d) I am not sure

23. What could possibly enhance wider adoption of PEA operations in the future?

(a) the availability of more data from controlled trials

(b) organizing dedicated medical/surgical workshops

(d) standardization of perioperative care protocols

(e) other, please specify

Results

One hundred and seventy-two surgeons in 43 countries (Table 2) expressed their interest in PEA surgery and completed the electronic questionnaire within 8 weeks of mailing. Most (>80%) Asia-Pacific surgeons with an interest in PEA surgery were experienced doctors who had practiced cardiac surgery for more than 10 years, with a personal workload exceeding 200 cardiac surgical operations per year. Three-quarters of the participating surgeons practiced in major academic or government hospitals that performed more than 1000 cardiac operations annually. Even though more than 75% of participating institutions did not have heart/lung transplantation or extracorporeal membrane oxygenation (ECMO) capabilities, PEA surgery was already being performed in 72% of them. Seventy percent of respondents (n = 120) were already familiar with the surgical technique. Of those, two-thirds had personally performed the PEA procedure (44% of all respondents), while one-third had only observed live surgery (26% of all respondents), mostly in their own institutions (Figure 1). The number of PEA procedures performed by each surgeon was less than 10 for 50%, and 11–35 for 35%, while 15% of surgeons had performed more than 36 PEA procedures each (Figure 2). Altogether, 1345 PEA procedures were reported to have been performed by 76 surgeons in the region, with less than 10% perioperative mortality in most experiences (70% of respondents), and 10%–30% for 20% of surgeons, while 10% who had personally performed the PEA procedure had a higher than 30% mortality rate. The overall functional outcome is shown in Figure 3. The principal difficulties encountered when starting to perform PEA procedures were selecting suitable candidates (65% of respondents), mastering the challenging surgical technique (20%), and learning perioperative care strategies (15%). Based on past experience, 3 indicators were equally believed to signify inoperability in any given patient: small vessel disease (34% of respondents), severe right ventricular failure (33%), and severe underlying parenchymal lung disease (33%). Twenty-eight percent of respondents (n = 48) believed that their institutional set-up was not appropriate to perform PEA surgery, and three-quarters (n = 129) believed that this procedure should be restricted to dedicated teams in certain institutions, affirming that the availability of heart/lung transplantation or ECMO capabilities was necessary in the providing institution. Amongst respondents with experience in PEA surgery, only surgeons who had access to such supportive facilities believed them to be fundamental. All surgeons who had already performed PEA procedures (n = 76), and 84% of surgeons who had not yet done so but believed that they work in a suitable set-up (n = 40) aimed to perform additional PEA procedures within the coming 5 years. Most respondents (82%) believed that attending live PEA surgery is necessary before launching a new PEA program, and the majority (90%) thought that colleagues with appropriate skills should be available to advise early in the learning curve. The expected number of suitable candidates for surgery ranged between 5 and 10 patients per year (69% of respondents), 11–35 patients per year (15%), and more than 35 patients annually (16%). The main factor likely to hinder a rise in the number of PEA procedures in any institution was believed to be the difficulty in attracting suitable candidates for surgery (57% of surgeons). Most surgeons (88%) in the Asia-Pacific region predicted that the total number of PEA procedures performed will rise within the coming 5 years, while 6% believed that this might be only a short-lived rise caused by transient curiosity. The primary factors believed likely to limit wider implementation of PEA surgery in the Asia-Pacific region in the foreseeable future were the limited recognition of CTEPH and of the possibility of surgical cure (75% of respondents), lack of clarity on indications and contraindications for PEA surgery (34%), and concern regarding an unacceptably high surgical risk (32%). Three approaches equally thought to possibly enhance wider acceptance of PEA surgery in the region in the projected future were dedicated medical/surgical workshops, the availability of more data from controlled trials, and the establishment of clear patient selection guidelines.

Table 2.

Participating countries.

Armenia, Australia, Azerbaijan, Bahrain, Bangladesh, Cambodia, China, Cyprus, Georgia, Hong Kong, India, Indonesia, Iran, Iraq, Japan, Jordan, Kazakhstan, Kuwait, Lebanon, Macao, Malaysia, Mongolia, Myanmar, Nepal, New Zealand, Oman, Pakistan, Palestine, Philippines, Qatar, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Syria, Taiwan, Thailand, Turkey, United Arab Emirates, Uzbekistan, Vietnam, Yemen

Figure 1.

Present familiarity with pulmonary thromboendarterectomy surgery amongst respondents.

Figure 2.

Number of pulmonary thromboendarterectomy (PEA) procedures performed by individual participants.

Figure 3.

Reported functional outcome of pulmonary thromboendarterectomy operations performed by respondents.

Discussion

This survey aimed to describe the present practice of PEA surgery in the Asia-Pacific region. Despite wide awareness, PEA surgery has been performed by only a few Asia-Pacific surgeons and in small numbers of patients. Nevertheless, this study shows a clear predisposition to perform more PEA procedures in the foreseeable future, thus exponentially increasing the overall number of PEA procedures undertaken in the region.

The primary factor that might limit wider implementation of PEA surgery in the Asia-Pacific region was believed to be the difficulty in attracting suitable candidates for surgery. There was a broad conviction that this is the consequence of limited recognition of PEA surgery as a potential cure for CTEPH. It was also believed that dissemination of PEA surgery may be held back by certain country-specific and center-specific issues, such as local medical practices and the availability of resources. Indeed, the challenge of attracting potential candidates for PEA surgery in a resource-limited setting was recently highlighted in the first report on the CTEPH experience in Mexico, where only one patient in fifty could undergo PEA surgery.⁷ Of note, PEA surgery was already being performed in many centers that did not have heart/lung transplantation or ECMO capabilities, and this indicates a lack of agreement among Asia-Pacific surgeons regarding the necessity for such resources.

Despite the evident need for substantially wider implementation of PEA surgery in the region, this opinion poll among Asia-Pacific surgeons underscores their preference to restrict this procedure to designated “expert PEA centers” (already defined as institutions that perform ≥20 PEA surgeries per year with a mortality rate < 10%).^5,8 In line with previous reviews,^1,6,9,10 it was widely believed that expert PEA centers can carry out optimal patient selection and better perioperative management compared to less experienced centers. Considering the dissemination of the operative technique, the majority of respondents also recognized the importance of the early learning curve, and considered that a surgeon should be supported by a colleague with considerable earlier experience in PEA surgery before operating independently.

Finally, the opinion poll acknowledged the need to organize dedicated PEA regional meetings where live demonstrations and local outcomes can be presented. In addition, these conferences can serve as platforms where clinical practice guidelines can be established and updated as appropriate for regional healthcare facilities. Such efforts were expected to enhance wider acceptance of the PEA surgery in the region in the projected future, and were equally thought likely to translate into generalized benefits for local patients.

Several limitations of this study should be considered when interpreting these data. The voluntary and anonymous nature of any survey may possibly generate incomplete or even questionable records that can influence epidemiological data. However, we believed that anonymity was a positive feature of this survey because it encouraged the participation of surgeons with limited experience or poor outcomes, as was evident in the results of the survey. Moreover, a realistic number of surgeons took part in the study, and they were based in equal percentages in university, government, and private practice institutions. Hence, we believe that this survey represents the overall state of PEA surgery in the Asia-Pacific region fairly well, and reflects the opinions of the largest contemporary group of surgeons with an interest in PEA surgery. Even though differences between individual countries undoubtedly exist in parallel with discrepancies in the development of health services,¹¹ the anonymous nature of survey design did not permit per country analyses nor identification of existing expert PEA centers. Bringing attention to certain institutions was not the purpose of this survey. We concluded that although cardiothoracic surgeons in the Asia-Pacific region appreciate that a lot of work is needed before PEA surgery is widely adopted, it is clear that many surgeons and additional institutions are already planning to implement the PEA procedure. To this end, bringing together an international working group on PEA in the Asia-Pacific region is currently ongoing, and is specifically dedicated to share experiences and advance the understanding of the practice and results of PEA surgery.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Condliffe

Kiely

Gibbs

. Improved outcomes in medically and surgically treated chronic thromboembolic pulmonary hypertension. Am J Respir Crit Care Med 2008; 177: 1122–1127.

Madani

Auger

Pretorius

. Pulmonary endarterectomy: recent changes in a single institution’s experience of more than 2,700 patients. Ann Thorac Surg 2012; 94: 97–103.

Machuca

de Perrot

. When to refer a patient with chronic thromboembolic pulmonary hypertension for pulmonary endarterectomy. Can J Cardiol 2015; 31: 509–514.

Delcroix

Lang

Pepke-Zaba

. Long-term outcome of patients with chronic thromboembolic pulmonary hypertension: results from an international prospective registry. Circulation 2016; 133: 859–871.

Wilkens

Lang

Behr

. Chronic thromboembolic pulmonary hypertension (CTEPH): updated recommendations of the Cologne Consensus Conference 2011. Int J Cardiol 2011; 154(Suppl 1): S54–60.

Pepke-Zaba

Delcroix

Lang

. Chronic thromboembolic pulmonary hypertension (CTEPH): results from an international prospective registry. Circulation 2011; 124: 1973–1981.

Al-Naamani

Espitia

Velazquez-Moreno

. Chronic thromboembolic pulmonary hypertension: experience from a single center in Mexico. Lung 2016; 194: 315–323.

Task Force for Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC); European Respiratory Society (ERS); International Society of Heart and Lung Transplantation (ISHLT). Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J 2009; 30: 2493–2537.

Rahnavardi

Yan

Cao

Vallely

Bannon

Wilson

. Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension: a systematic review. Ann Thorac Cardiovasc Surg 2011; 17: 435–445.

10.

Escribano-Subías

del Pozo

Román-Broto

. Management and outcomes in chronic thromboembolic pulmonary hypertension: from expert centers to a nationwide perspective. Int J Cardiol 2016; 203: 938–944.

11.

Mayer

Jenkins

Lindner

. Surgical management and outcome of patients with chronic thromboembolic pulmonary hypertension: results from an international prospective registry. J Thorac Cardiovasc Surg 2011; 141: 702–710.