The minimally invasive spine surgery (MISS) is a rapidly developing field with an
enormous potential. The main objective of this wonderful technology is to achieve
the desired surgical objective with minimal patient morbidity and lesser postoperative
complications. It is to be remembered that minimally invasive spine surgery is in
itself, not an operative procedure. However, it is related to the access toward achieving
an operative goal. Hence, MISS is a tool, albeit not a treatment, for the spinal pathologies
and the purported benefit of MISS is probably related to the minimalism it affords
in achieving the access and the surgical exposure. The role of MISS has increased
tremendously in the last decades with improvements in technology, and initial experiences
are being reported for basic procedures such as discectomy and laminectomy. The MISS
techniques have been extensively refined recently with modern applications being used
for the more advanced spinal fixations and interbody fusions.
The main theoretical benefit of MISS is the excellent panoramic visualization of the
offending pathology, however, the two-dimensional vision is the major impediment and
henceforth, the steep learning curve for improving the hand-eye coordination. The
minimalistic approach affords preservation of the normal anatomical structures along
with a smaller incision, which theoretically should transform into lesser postoperative
morbidity, reduced hospital stay, and decreased perioperative blood loss.
MISS has had an enormous impact on the patient outcomes, with patients operated for
pathologies such as lumbar disc and lumbar canal stenosis, being discharged on the
same day of treatment and these techniques can also be offered to patients with medical
comorbidities, morbid obesity, and advanced age. However, in this era of evidence-based
medicine, there are increasing concerns of the superiority of MISS over the more conventional
standard approaches. There have been many studies in literature regarding the safety
and efficacy of MISS techniques. However, comparison studies with good clinical designs
have been lacking in the literature. Most of these studies have shown equivalent results
in terms of improvement in functional outcome with relatively short, though nonsignificant,
perioperative advantages, such as reduced hospital stay with its attendant reduction
in hospital costs, lesser perioperative blood loss, and decreased perioperative analgesic
usage. The lumbar discectomy was one of the first procedures to be performed using
MISS techniques, however, MISS discectomy has a comparative efficacy with standard
open approaches in various studies in literature. Arts et al[1] conducted a randomized controlled trial comparing tubular discectomy with conventional
microdiscectomy. The authors concluded that there was a small but statistically significant
improvement in visual analog scale (VAS) scores and functional outcome with standard
surgery. However, there was no difference between the perioperative morbidity, recovery
rates, and complications among the two approaches. Ryang et al[2] compared 60 patients undergoing open microdiscectomy (MD) or MISS procedure. They
found small nonsignificant differences favoring MISS in terms of operating time, blood
loss, incision length, and complications. No difference was found in VAS scores, Oswestry
disability index scores, and the 36-item short form survey (SF-36) scores at a mean
follow-up of 16 months. The proponents of MISS procedures relate better functional
outcomes to lesser tissue trauma. However, a prospective randomized controlled trial
concluded that there was no real clinical advantage of the less traumatized posterior
musculature.[3] Hence, the hypothesis that a less traumatized back muscle leads not only to a quicker
recovery but also to less chronic back pain could not be confirmed. In conclusion,
the literature does not appear to favor MISS over the standard MD in cases of unilateral
single-level lumbar discectomy. However, there can be small benefit in operating time,
blood loss, and incision length.
Similarly, no rigorous prospective controlled trial exists comparing MISS with a standard
open laminectomy procedure and there does not appear to be a robust claim in support
of MISS as compared with open laminectomy for lumbar canal stenosis.[4]
Hence, a robust clinical evidence favoring MISS over open approaches is lacking and
both the procedures result in excellent long-term outcomes with minimal morbidity.
There is a need to develop evidence-based recommendations and the studies conducted
till now warrant verification in larger prospective registries and well-designed randomized
controlled trials in future. The benefit of MISS seems to be more plausible in the
more complex procedures associated with exposure-related morbidity. However, at the
same time, the operating surgeon should keep in mind that the intended surgical goal
should never get jeopardized.
