Overall vessel expansion induced by a stretch of the arterial wall led to lumen enlargement immediately after balloon pulmonary angioplasty, according to results recently published in Circulation: Cardiovascular Interventions.
The data also show that lesion type may dictate the amount of fibrous tissue, making it beneficial to change the balloon size in correlation with the lesion type.
“Balloon pulmonary angioplasty has become a therapeutic option for patients with chronic thromboembolic pulmonary hypertension who are ineligible for pulmonary endarterectomy. Previous [studies] demonstrated that thromboembolic lesion types influence the outcome and complication rate of balloon pulmonary angioplasty,” Hiroto Shimokawahara, MD, PhD, from the departments of cardiology and clinical science at the National Hospital Organization Okayama Medical Center in Japan, and colleagues wrote in the study background. “It is not fully understood how the lumen enlarges immediately after balloon pulmonary angioplasty by simple balloon dilatation.”
Shimokawahara and colleagues included 71 patients with chronic thromboembolic pulmonary hypertension (CTEPH) and a total of 326 lesions in a retrospective investigation of IVUS measurements to assess how the lumen enlarges immediately after balloon pulmonary angioplasty.
The researchers assessed cross-sectional areas of the external elastic membrane and lumen measured by IVUS before and after balloon pulmonary angioplasty for each lesion type.
The lesion types were then compared, and it was found that the proportion of the area occupied by fibrous tissue was smallest in the type A lesions and largest in the type C lesions.
According to the researchers, due to an increase in the external elastic membrane cross-sectional area, the mean lesion lumen cross-sectional area was increased after balloon pulmonary angioplasty from 23.2 ± 12.9 mm2 to 27.2 ± 14.3 mm2 (P < .001) and additionally showed a slight decrease in fibrous tissue plus media cross-sectional areas from 17.7 ± 11.7 mm2 to 17.3 ± 11.1 mm2 (P < .001).
There was a strong association between the change in lumen and the change in external elastic membrane cross-sectional areas (r2 = 0.762; P < .001), according to the researchers.
“In the present study, changes in the lumen [cross-sectional areas] of pulmonary arteries strongly correlated with changes in [external elastic membrane cross-sectional areas],” the researchers wrote. “Thus, lumen enlargement immediately after [balloon pulmonary angioplasty] would be mainly because of vessel stretching.” by Dave Quaile
Disclosures: Shimokawahara reports that he receives lecture fees from Actelion Pharmaceuticals, Bayer Yakuhin, Daiichi Sankyo and Nippon Shinyaku. Please see the study for all other authors’ relevant financial disclosures.