Pulmonary Thromboendarterectomy Should Be Considered for PH Before Transplant, Case Report Contends

José Lopes, PhD avatar

by José Lopes, PhD |

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Pulmonary thromboendarterectomy

Chronic thromboembolic pulmonary hypertension (CTEPH) may be mitigated by pulmonary thromboendarterectomy, which prevents the need for lung transplant, a new case report shows.

The study, “Pulmonary Thromboendarterectomy for Pulmonary Hypertension Before Considering Transplant,” appeared in The Ochsner Journal.

CTEPH is observed in approximately 4% of cases of pulmonary embolism. It is defined as a precapillary condition associated with an occlusive thrombus (blood clot) after three months of therapeutic anticoagulation and a mean pulmonary artery pressure higher than 25 mmHg.

Surgical intervention in cases of CTEPH can be curative. Surgery requires cardiopulmonary bypass and deep circulatory arrest with pulmonary thrombectomy (removal of the thrombus) and bilateral endarterectomy (PTE; a procedure to clean the artery to prevent stroke).

The complexity of the surgery and the location of the thrombus are key questions when considering whether to operate. If surgery fails, lung transplant is the next best surgical option.

Importantly, PTE has a lower mortality rate than lung transplant, and does not preclude transplant if the PH does not improve. Two-year survival rates are approximately 10% higher in patients who undergo PTE compared to those who do not.

Medical treatment is another option, although patients treated medically have higher mortality rates and worse functional status than those who undergo surgery. However, the use of new disease-modifying agents still may be an important help.

Approximately two-thirds of patients with CTEPH can be operated on. Amelioration of pulmonary hypertension (PH) and right heart dysfunction, which is typically an indicator of the severity of PH, is often swift after successful PTE, with complete and permanent remodeling, usually by three months.

A medical team led by Michael Bates, MD, from the Department of Surgery, Ochsner Clinic Foundation, New Orleans, La., presented a case of surgical treatment for CTEPH and the patient’s postoperative course.

Residual PH after PTE occurs in approximately 35% of patients. Overall, four-year mortality rates after surgery are approximately 15%, and mortality rates correlate with the postoperative pulmonary vascular resistance.

A 35-year-old female who presented three months after a pulmonary embolus was found to have completely occluded her left pulmonary artery. The patient had been started on therapeutic anticoagulation, but continued to have shortness of breath and exercise intolerance. She was diagnosed with PH as pulmonary artery pressure was 81/33 mmHg, with a mean pressure of 52 mmHg. The right atrial pressure also was severely increased at 29 mmHg.

The patient’s echocardiogram revealed severe tricuspid regurgitation (the tricuspid valve does not close tight enough) and severe right ventricular dysfunction. PTE was performed. The patient did not require blood transfusions and was followed postoperatively by the heart failure team.

After one month of cardiac rehabilitation and continued anticoagulation therapy, the patient’s six-minute walk distance (a measurement of functional capacity, response to therapy and prognosis) improved from 396 meters to 670 meters at seven months, which is more than the median improvement observed in large studies.

Importantly, her pulmonary artery pressure was significantly reduced to 55/17 mmHg with a mean pressure of 31 mmHg. The patient’s right atrial pressure also was reduced from 29 mmHg to 13 mmHg. Of note, tricuspid regurgitation stayed consistently mild.

Overall, although the patient “had subjective symptomatic relief almost immediately postoperatively, the objective measures also changed and improved. It remains to be seen what objective benefit she may derive from her medical therapy.”

The medical team stated that CTEPH is likely under-recognized, as “symptoms are often vague and may not manifest for many years.” Patients with PH or a history of pulmonary embolism should be screened for CTEPH and surgery should be evaluated as an option, they said.