Researchers from the University of California, San Diego, presented a new study at the 2014 American Thoracic Society International Conference revealing the effects of pulmonary thromboendarterectomy (PTE) in patients with chronic pulmonary thromboembolic disease, suggesting a positive effect in patients’ conditions after the procedure.
Daniel Crouch, MD, pulmonary and critical fellow at UCSD and lead investigator on the study reports that “Over the past five years, an increasing number of patients with symptomatic chronic thromboembolic disease, without severe pulmonary hypertension, are being offered and choosing to undergo the surgery. These patients have symptoms that create a major burden in their lives. However, given that they do not have severe pulmonary hypertension and cardiac dysfunction, the benefits of the surgery must greatly outweigh the risks. ”
The surgical procedure is a complex one, consisting of placing the patient on a heart-lung machine that cools the body to reduce its need for oxygen. While the machine works for 20 minutes, the surgeon can remove clots and scar tissue from the patient’s arteries. Due to the complexity of the procedure, it has been used only in patients whose pulmonary thromboembolic disease causes severe hypertension and whose condition has not responded to alternative therapies.
USCD has been a leader in performing the procedure, using it since 1970s. The research group reviewed the patients who underwent PTE at UCSD between July 2010 and June 2013, finding 64 subjects with pre-operative pulmonary resistance values (PVRs) inferior to 300 dyn/cm5 and 355 patients with values above this value that could be used as a guide to identify patients with severe and non-severe pulmonary hypertension. Data revealed that the patients shared similar age and composition, however, the body mass index was higher in the low PVR group.
Comparing both groups’ disease development, the low PVR group had a statistically significant lower rate of repercussion lung injury (7.8% vs. 25.9%), fewer complications like delirium (7.8% vs. 14.9%), pneumonia/tracheobronchitis (6.3% vs. 15.5%), and most significantly, a lower mortality (0 vs. 1.1%). The differences continue even with the patients’ recoveries, with the group with low PVR needing less time on a ventilator (1.7 vs. 3.2 days), in the ICU (4 vs. 5.8 days), and in the hospital (13 vs. 16.3 days).
During the presentation, Crouch added that patients with low PVR showed “great benefit” in follow up visits, conducting this study as a follow-up study to formally evaluate improvement in their functional status and quality of life. “Although pulmonary thromboendarterectomy is the procedure of choice for CTEPH, there are important questions to answer before it can be considered the treatment of choice in the low PVR patient population, as with anything we offer patients, we want to prove it’s the best therapy” Crouch said.