Description:
Chronic obstruction of the large pulmonary arteries by persistent (> six months) emboli is a potentially treatable cause of pulmonary hypertension and right-sided heart failure. Fibrotic masses in major pulmonary arteries may result when pulmonary thrombi fail to resolve normally, ultimately leading to pulmonary hypertension. Other factors, such as age of the embolus or defects in the fibrinolytic system, may also be important. In many cases, there is no documented history of embolization. Early diagnosis is difficult since the patients are rarely symptomatic until the development of pulmonary hypertension and right-sided heart failure. Even then, diagnosis can be difficult and depends on a high index of suspicion, ventilation/perfusion scans and careful and experienced interpretation of pulmonary angiograms.

Over the last two decades, Moser and colleagues at the University of California at San Diego (UCSD) have developed a technique for surgical removal of the obstructing thromboemboli, as a curative alternative to lung transplantation. The surgery involves cardiopulmonary bypass, and since the obstruction is typically bilateral, the surgical approach requires a median sternotomy. Removal of the organized thrombus requires meticulous dissection in a bloodless field, which in turn requires profound hypothermia with periods of cardiac arrest. In addition, a vena cava filter is usually placed to prevent recurrence of emboli.

Policy:
Pulmonary thromboendarterectomy of chronic thromboembolic obstruction due to fibrosed pulmonary emboli involving the pulmonary arteries may be considered MEDICALLY NECESSARY.

Typical patient selection criteria for this procedure include New York Heart Association Class III or IV, a mean pulmonary artery pressure above 30 mm Hg or a pulmonary vascular resistance of greater than 300 dynes/sec/cm².

Rationale:
In 1993 Jamieson and colleagues published the results of pulmonary thromboendarterectomy in 150 cases performed by one surgeon.¹ A total of 13 patients died for an overall in-hospital mortality of 8.7 percent. Immediate declines in the hemodynamic measures of surviving patients were highly significant: The mean pulmonary artery pressure dropped from 48.5 to 28.9 mm Hg and the pulmonary vascular resistance dropped from 936 to 299.4 dynes/sec/cm². Of 150 patients who returned for repeat hemodynamic testing from six to 24 months after the surgery, hemodynamic improvement remained stable in 47.² One year after surgery, New York Heart Association (NYHA) classifications were recorded for 117 patients of the total 150. Preoperatively, the distributions for Class I through IV were as follows: 0, five, 49 and 63. One year after surgery, the distribution was 85, 26, six and zero. Therefore, preoperatively, 95 percent of the patients were NYHA Class III or IV, whereas postoperatively, 95 percent of patients were in NYHA Class I or II.

The bulk of the literature comes from physicians at the University of California at San Diego (UCSD). These physicians emphasize the importance of the learning curve of this challenging surgery, and the importance of having a dedicated staff. Therefore, patients should be aware of the institutional experience with this surgery.

References:

1. Jamieson SW, Auger WR, Fedullo PF et al. Experience and results with 150 pulmonary thromboendarterectomy operations over a 29-month period. J Thorac Cardiovasc Surg 1993; 106(1):116-27.
2. Moser KM, Auger WR, Fedullo PF et al. Chronic thromboembolic pulmonary hypertension: clinical picture and surgical treatment. Eur Respir J 1992; 5(3):334-42.
3. Thistlewaite PA, Mo M, Madani MM et al. Operative classification of thromboembolic disease determines outcome after pulmonary endarterectomy. J Thorac Cardiovasc Surg 2002; 124(6):1203-11.
4. Jamieson SW, Nomura K. Indications for and the results of pulmonary thrombendarterectomy for thromboembolic pulmonary hypertension. Semin Vasc Surg 2000; 13(3):236-44.
5. Archibald CJ, Auger WR, Fedullo PF et al. Long-term outcome after pulmonary thromboendarterectomy. Am J Respir Crit Care Med 1999; 160(2):523-8.

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

"Current Procedural Terminology ^© American Medical Association. All Rights Reserved" 

History From 2014 Forward