Cannabis use may negatively impact outcomes in peripheral artery bypass (PAB) surgery, suggests a study published in Annals of Vascular Surgery.
Researchers analysed more than 11 000 available cases to review patient cannabis use and postoperative outcomes for lower extremity bypass after 30 days and one year. The minimally invasive PAB procedure uses a vein or synthetic to tube to divert blood around a narrowed or blocked artery in a leg.
Results reveal that patients who used cannabis prior to lower extremity bypass had decreased patency, meaning the graft had a higher chance of becoming blocked or occluded, and were 1.25 times more likely to require amputation one year after surgery. Cannabis users were also 1.56 times more likely to use opioids after discharge.
“The findings show a need for screening for cannabis use and open conversations between patients and clinicians to help inform preoperative risk assessment and decision-making for lower extremity bypass,” said senior author Peter Henke, MD, FACS, FAHA
“While its exact mechanisms are unclear, cannabis and its active compounds play a role in platelet function and microcirculation that may lead to decreased rates of limb salvage after lower extremity bypass,” Henke said.
Around 43% of individuals in the United States and Canada have used cannabis. Previous studies suggest cannabis use has effects on the cardiovascular system, including increased risk of heart attack and stroke. The study did not find any association with stroke or heart attack after lower extremity bypass.
While future study is needed to further understand cannabis’ full effect on outcomes, researchers note, the findings will help clinicians counsel patients who are undergoing vascular surgery.
“While past studies on the effects of cannabis use on pain response suggested an increase in pain tolerance after smoking cannabis, our studies and other contemporary findings show the opposite,” said Drew Braet, M.D., first author and integrated vascular surgery resident at U-M Health. “Given the increase in cannabis use and abuse in conjunction with the opioid epidemic, the results suggest a need for a better understanding of pain management for cannabis users who are having vascular surgery.”
