Minimally invasive tubular approach to intramedullary cavernous malformations

Abstract

Background: Advancements in minimally invasive spinal surgery have led to an expansion of targeted pathologies as well as improvements in surgical outcomes compared to their conventional counterparts through open laminectomy; however, this technique is rarely mentioned in the literature for intrinsic cord lesions. The authors present a novel minimally invasive, dorsolateral, and expandable tubular approach for the resection of an intradural, intramedullary thoracic cavernous malformation (CM).

Case descriptions: A 52-year-old male patient presented with rapidly progressive myelopathy and loss of ambulatory capabilities, with which magnetic resonance imaging revealed a hemorrhagic CM within the thoracic spinal cord. The CM was successfully resected through a minimally invasive tubular approach utilizing a dorsal root entry zone myelotomy. Postoperative imaging confirmed gross resection. His motor examination rapidly recovered, and he remains ambulatory with the use of a cane at a 2-year follow-up.

Conclusion: This novel minimally invasive approach is a promising technique for well-selected cases of symptomatic spinal CMs. Further exploration and potentially randomized studies are necessary to fully affirm the tubular approach's suitability for the treatment of intradural intramedullary CMs compared to conventional techniques.

Keywords: Angioma; Cavernoma; Cavernous malformation; Dorsolateral myelotomy; Intradural intramedullary; Minimally invasive.

Figure 1:

(a) Preoperative T2 mid-sagittal magnetic resonance imaging (MRI) reveals the 1.8 × 1.0 cm expansile cavernoma with a fluid level, suggesting recent hemorrhage. (b) Preoperative T2 axial MRI demonstrated the same lesion.

Figure 2:

An intraoperative owl’s eye view through the tubular retractor visualizing the intramedullary lesion. The dorsal rootlets are clearly visualized, demarcating the dorsal root entry zone.

Figure 3:

The dashed line in this figure represents the location of the myelotomy made just lateral and longitudinal to the fasciculus gracilis along the dorsal root entry zone.

Figure 4:

(a) Postoperative T2 mid-sagittal magnetic resonance imaging (MRI) at 18 month follow-up reveals resection of the lesion with small region of hemosiderin deposition. (b) Postoperative T2 axial MRI at same 18 month follow-up.