Surgery performed by Dr. César Yanes-Guandique
This complete surgery can be seen in the online surgery app SurgSchoolwhere this case of intradural dorsal lipoma performed by the Dr. César Yanes-Guandique, neurosurgeon of Neuroclinic (El Salvador), with extensive experience in intradural spinal pathology.
Clinical Introduction
Intradural dorsal lipoma is a rare, benign lesion characterized by mature adipose tissue located within the dural sac, usually in close proximity to the pia mater and dorsal nerve roots. In adults, its presentation is typically progressive, with symptoms of spinal cord compression: hypoesthesia, paraparesis, and, in more advanced stages, sphincter dysfunction.
Surgical intervention is indicated in cases of progressive neurological deterioration or clear signs of spinal cord compression on magnetic resonance imaging. Unlike other intradural extramedullary lesions, the goal of surgery is not complete resection, but rather... functional decompression of the spinal cordminimizing the risk of neurological sequelae.
Preoperative planning
Magnetic resonance imaging is the fundamental study. Intradural lipomas show hyperintense signal on T1 and T2, with suppression on fat-saturated sequences, and allow precise definition of the relationship with the spinal cord and dorsal roots.
From an anatomical point of view, it is critical to anticipate:
- The degree of adherence of the lipoma to the pia mater.
- The possible compromise of the dorsal root entry.
- The tumor's vascularization is usually rich, with fibrovascular bands firmly attached to the dura mater.
Patient selection should be based on a clear clinical-radiological correlation, assuming that the surgery aims to relieve compression and not a radical excision.
Description of the surgical approach
The posterior approach by laminectomy or focal laminotomy, chosen by the Dr. Yanes-GuandiqueThis technique is the most commonly used for intradural dorsal lipomas. It allows direct and safe access to the dural sac, with adequate control of the dorsal venous plexus, which is usually particularly well-developed at this level.
This approach offers the advantage of wide exposure of the posterior cord, although it requires meticulous microsurgical technique to avoid vascular and neural damage, especially during dural opening and lipoma dissection.
Key surgical steps
The durotomy is performed in a controlled manner, using techniques that minimize the risk of spinal cord injury. The use of a Frazier-type cannulated dissector as a guide for the scalpel allows for precise and safe opening of the dura mater, especially in a field where working space is limited.
Once the dura mater is opened, the fully intradural lipoma is identified, frequently adhered to both the dura mater and the pia mater of the posterior column. In many cases, associated cystic formations are observed, along with a deep plane where the compressed spinal cord is clearly visible.
The dissection must be progressive and lateralcarefully releasing the adhesions. It is essential to assume that, when there is infiltration of the dorsal root entry or of the cord itself, Complete resection is neither safe nor desirableThe strategy focuses on reducing the lipomatous volume until effective decompression is achieved.
Volume reduction is effectively achieved using an ultrasonic aspirator, allowing for controlled debulking of the fibroadipose tissue. Given the highly vascular nature of lipomas, hemostatic control is critical throughout this phase.
Skeletonization of the dorsal roots and exposure of the posterior column mark the endpoint of decompression, demonstrating a clear decrease in spinal cord compression without excessive traction on neural structures.
Critical points and risks
The main structures at risk are the posterior column of the spinal cord, the dorsal roots, and the dorsal venous plexus. Aggressive dissection in the area of root insertion can lead to irreversible sensory or motor deficits.
Profuse bleeding is common due to the rich vascularization of the lipoma and its fibrovascular bands. Prevention involves slow dissection, judicious use of the ultrasonic aspirator, and meticulous hemostasis.
Surgical tips & pearls
The key technical point is knowing when to stop the resectionForcing complete excision in the presence of firm adhesions to the pia mater or dorsal roots exponentially increases neurological risk without additional clinical benefit.
Wide dural plasty with lyophilized dura mater reduces the risk of postoperative adhesions and facilitates tension-free closure, which is especially relevant in intradural surgeries.
Common mistakes and pitfalls
A common mistake is underestimating the vascularization of the lipoma, which leads to difficult-to-control bleeding and unnecessary loss of surgical space. Another significant pitfall is attempting to detach the lipoma from the nerve root, a maneuver that can result in permanent neurological damage.
Results and postoperative considerations
In the immediate postoperative period, a transient neurological deterioration, such as paraparesis, may be observed secondary to spinal cord manipulation. However, with adequate decompression, functional recovery is usually progressive in the following days.
In this case, the patient showed a clear improvement in muscle strength and recovery of sphincter control, allowing hospital discharge without complications on the fifth postoperative day.
For whom is this surgery especially useful?
This surgery is particularly formative for advanced residents and junior attending physicians in spinal neurosurgery, as it exemplifies realistic intraoperative decision-making in intradural pathology. For experienced surgeons, it reinforces the concept of functional decompression versus radical resection in benign lesions adhered to critical structures.
