A high body mass index (BMI) has no significant bearing on functional and clinical outcomes for patients treated by minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), according to a new study published in the European Spine Journal.
The retrospective study of 207 patients, undertaken by Ayush Sharma (Dr. B.A.M. Hospital, Mumbai, India) et al was designed to investigate whether or not a high BMI affects the outcomes following MI-TLIF for degenerative lumbar pathologies.
It included patients operated between January 2016 and January 2020 with at least one-year follow-up. Patients were classified into normal, overweight and obese based on their BMI.
The operative and outcome measures used for assessment were surgical time, blood loss, number of levels operated upon, skin incision length, day of independent mobilisation, total hospital stay including ICU stay, return to work and Visual Analogue Score (VAS) for back pain (VAS-BP) and leg pain (VAS-LP) and Oswestry Disability Index (ODI).
Attainment of Minimal Clinically Important Difference (MCID) for the scores was calculated. Multivariate analyses were done to assess the effect of BMI on different parameters.
The findings showed that whilst blood loss and postoperative ICU stay were found to be higher in the obese patients, all other variables were comparable. All patients had significant improvements in VAS-BP, VAS-LP and ODI scores, with no inter-group variability.
Additionally, the MCID attainment was similar, as was the patient satisfaction rating at one year and the willingness to undertake surgery again for a similar disease. The overall complication rate was 14.9% and again was comparable among both groups.
Speaking to Spinal News International, Sharma said: “We always felt it was much easier to offer a minimally invasive approach in patients with high BMI compared to an open approach. Most of the surgeons will agree with struggle in muscle retraction during open TLIF in patients with high BMI.
“Our aim was to study if the patients’ outcomes in minimally invasive TLIF were affected by high BMI. Our work is just an insight and much more research is needed before we can conclude if minimally invasive TLIF in high BMI patients indeed is favourable compared to open TLIF. But we do believe why dig a pond to draw water if you could get it by digging a well.”