Smoking presents dangers for patients undergoing embolization in lungs

Smokers have a smaller chance of undergoing a successful procedure to treat blood vessel abnormalities in the lungs, according to new research out of the Mayo Clinic.

Patients with pulmonary arteriovenous malformations (PAVMs) have atypical connections between arteries and veins in their lungs, in many cases this is due to the inherited disorder Hereditary Hemorrhagic Telangiectasia (HHT). The condition can worsen and ultimately cause fatal complications, wrote study senior author Sanjay Misra, MD, in a news release.

Upon analyzing more than 100 patients with HHT—separated into smokers and non-smokers—Misra et al found the former group faced higher five-year persistence rates of PAVMs compared to those who did not smoke.

"Our five-year data showed that the cumulative incidence of persistence was 17.3 percent, or almost one in five patients," Misra, an interventional radiologist at the Mayo Clinic Department of Radiology in Rochester, Minn., said in the same release. "Smoking more than 20 pack years was associated with a fivefold increase in PAVM recurrence."

When AVMs become symptomatic, interventional radiologists use coils to embolize them, Misra added. During that procedure a catheter is maneuvered through a blood vessel in the leg to the area of the PAVM. Then, a small coil is inserted to block the PAVM. While effective, the malformations still persist in some patients.

To determine how smoking could impact post-embolization PAVM persistence, the team retrospectively analyzed 103 patients with HHT who underwent embolization between January 2000 to August 2017. This totaled 373 PAVMs and 151 distinct procedures.

Overall, PAVMs persisted following treatment in more than one-third of 20 pack-year smokers compared with 12.2% of nonsmokers. Those who used tobacco at the time of embolization had a five-year persistence rate of 26.3%, versus 13.5% in those who didn’t smoke. 

“Smoking creates an inflammatory response," Misra said. "More inflammation creates a greater likelihood of failure for smokers compared to those who never smoked."

Going forward, the results must be confirmed in larger studies, but could help urge patients with HHT who may consider embolization to quit smoking.

"Smoking cessation is very important if these patients want to help themselves and avoid further procedures," Misra said. "We should urge current smokers to stop smoking before treatment."

The full study was published online July 30 in Radiology.