Microsurgical decompression provided more relief in nonsmokers vs smokers

After microsurgical decompression, the improvement in ODI scores was less for smokers vs nonsmokers.

Microsurgical decompression for one-level and two-level central lumbar spinal stenosis resulted in improved Oswestry Disability Index scores for the entire 825-patient cohort in this multicenter observational registry-based study, but the procedure yielded significantly greater improvement in those scores at the 1-year follow-up in nonsmokers.

Although this surgery was associated with better outcomes among nonsmokers at 1-year follow-up, the proportion of smokers who attained a minimum clinically important difference (MCID) in Oswestry Disability Index (ODI) scores was still high, without any significant difference in complication rates between the two groups, according to Charalampis Giannadakis, MD, one of the investigators.

Giannadakis presented the findings at the EuroSpine Annual Meeting.

“Microsurgical decompression is a safe and effective surgical treatment option for lumbar spinal stenosis in smokers. Despite the lower reduction in ODI, which was observed in smokers, microsurgical decompression provides a considerable improvement in the vast majority of those patients as well, at the expense of a low rate of complications, which mostly consists of minor ones,” he told Spine Surgery Today.

Smokers had less ODI improvement

Giannadakis and colleagues compared outcomes of 619 nonsmokers and 206 smokers who underwent microdecompression for one-level and two-level central lumbar spinal stenosis at 1-year follow-up. They used data for the study from the Norwegian National Registry for Spine Surgery.

The researchers noted there was a statistically significant difference between preoperative ODI and ODI at 1-year postoperatively of 17.3 points for the entire patient population. However, the smokers experienced less ODI improvement than the nonsmokers at final follow-up, according to Giannadakis.

Despite the higher baseline ODI of smokers, a predictor for higher reduction in ODI postoperatively, this group experienced a reduction in ODI score that was 4.3 points less than for the nonsmokers, he said.

“Adjusting for other factors, smoking was also shown to have a negative impact of similar magnitude in the regression analysis,” Giannadakis said.

Significant difference in MCID

Giannadakis and colleagues determined a 10-point or greater ODI improvement was the MCID for this patient cohort. There was no statistically significant difference between smokers and nonsmokers who achieved the MCID for ODI improvement, based on the results.

“Although less likely than nonsmokers, the percentage among smokers who achieved a MCID, the value of which was defined in this study based on a consensus article, was still high (60.8%) and only 8.8% less than MCID achieved by nonsmokers (69.6%),” Giannadakis said.

There was no statistically significant difference between smokers and nonsmokers in terms of length of hospital stay for one-level or two-level procedures. In addition, there was no statistically significant difference between the two groups for operative time or intraoperative, perioperative or postoperative complications.

About 11.6% of the patients who were nonsmokers developed a complication compared to 9.2% of the patients who were smokers.

Giannadakis noted the presence of major complications in these patients, such as nerve injury, pulmonary embolism or deep vein thrombosis, was low. – by Robert Linnehan

Reference:
Giannadakis C, et al. Paper #46. Presented at: EuroSpine Annual Meeting; Sept. 2-4, 2015; Copenhagen, Denmark.

For more information:
Charalampis Giannadakis, MD, can be reached at Department of Neurosurgery, St. Olavs University Hospital, Olav Kyrres gt. 17, 7009 Trondheim, Norway; email: charalampis.giannadakis@ntnu.no.

Disclosure: Giannadakis reports no relevant financial disclosures.