Similar to traditional open surgery, proper patient selection for MISS is one of the most important prerequisites for successful outcomes. Patients who failed to improve with a lengthy and well-structured conservative management program (including physical therapy, oral pain medications, activity modification, pain interventions, nerve blocks, etc.) are considered candidates for surgical interventions as long as the surgical benefits outweigh the risks of the procedure. Surgeons should counsel patients with certain factors that may negatively affect the surgical outcomes; these include, but are not limited to, obesity (BMI above 30 kg/m²), immunocompromised status, elderly with multiple medical morbidities, active smoking status, active worker compensation claims, employment status, depression, narcotic dependence, and patients with secondary gain.⁷, ⁸, ⁹

MISS is a field that is rapidly evolving owing to technical innovations, and therefore there is a considerable inherent learning curve and technical challenges with potentially associated complications. In a systematic review, durotomy was found to be the most common complication associated with lumbar microdecompressive procedures. In addition, implant malposition, neural injuries, and nonunions were noted in early MIS lumbar fusions. The authors noted that the learning curve was overcome for operative time and complications as a function of case numbers in 20 to 30 consecutive cases for most MIS lumbar decompression and fusion techniques.¹⁰ More recently, it has been suggested that continued surgical experience in minimally invasive lumbar decompression is associated with improved perioperative parameters (operative time, length of hospital stay). However, the authors noted similar improvement in overall clinical outcomes regardless of the surgical experience.¹¹ Finally, the authors recommend that surgeons begin with simple MIS procedures, and ensure that they have adequate skills with open standard spine surgery before attempting MIS instrumentation.¹²

Careful and meticulous handling of the paraspinal soft tissue envelope and neurovascular structures is one of the guiding principles of MISS, which results in minimizing approach-related morbidities. Although MISS skin incisions tend to be limited in size, the restricted access should never prevent the use of adequate surgical technique in treating a given disorder. To operate effectively, a properly localized incision is crucial to provide direct access to the spinal pathology. This should be done using C-arm fluoroscopy and carefully examining the preoperative imaging prior to commencing the surgical procedure. Also, special attention should be given to the trajectory that will provide the best operative visualization, and cognizance taken of the surrounding critical visceral and vascular structures to be protected. After the skin is incised, anatomic neurovascular and muscular planes are developed using gentle dilation and splitting rather than cutting or stripping the surrounding soft tissues. Use of the surgical microscope and/or surgical loupes provides optimal illumination and magnification of the surgical field despite the limited surgical approach.