Minimally Invasive Paramedian Transmuscular Surgical Approach for Intracanal Tumors: Case Series, Microsurgical Technique and Outcomes

Introduction: Minimally invasive techniques allow access through a smaller paramedian incision which allows preservation of the posterior tension band, maintaining the biomechanics and stability of the spine. In this study, we describe our technique and present our 16-year experience of minimally invasive surgical approach for the resection of spinal tumors.

Methods: A retrospective review of all spinal tumor cases who underwent minimally invasive surgical resection using the tubular retractor system at Hospital Universitario San Ignacio in Bogotá, Colombia between January of 2008 and June of 2023 was conducted. All data were obtained from the databases of the Neurosurgery Department and medical records. Approval for the study was obtained from the Institutional Ethics Committee.

Results: During the study, 137 patients with intracanal tumors underwent surgical resection, including 56 minimally invasive procedures. The mean age was 53.7 ± 15.2 years (range: 8-78), with 42 females (30.7%) and 35 patients (25.6%) over 55 years old. Chief complaints included sensory deficits (53.6%), motor weakness (51.8%), and back pain (50%). Tumors were primarily located in the thoracic spine (51.8%, 29 cases), followed by cervical (19.6%, 11 cases) and lumbosacral (16.1%, 9 cases). The most common tumors were meningiomas (48.2%) and schwannomas (33.9%). Gross-total resection was achieved in 87.5% of cases. Mean operative time was 143.5 minutes, with blood loss averaging 220 ml. Cervical tumors had a higher risk of incomplete resection (p = 0.012), while fibrin glue use showed no significant association with CSF leaks (p = 0.125). Mean hospital stay was 3 days, with CSF leaks and new neurological deficits occurring in 4 patients (7.1%).

Conclusion : Minimally invasive surgical approach allows an adequate exposure for total resection with a lower incidence of complications, in a shorter surgical time and without causing greater repercussions on spinal stability compared to the conventional open approach.