Left Lateral Orbital Decompression
This is Richard Allen at the University of Iowa. This video demonstrates a left lateral orbital decompression.
A lateral canthotomy is performed followed by an upper and lower cantholysis. This procedure can also be performed through a lateral lid crease incision.
4-0 silk suture is placed for traction during the case.
Dissection is then carried out to the underlying periosteum of the lateral orbital rim which has been incised with the monopolar cautery.
The Freer periosteal elevator is then used to elevate the periosteum from the underlying lateral orbital wall.
Bone removal is then performed with a high speed drill using a cutting burr.
The initial goal is to remove as much of the zygoma posterior to the orbital rim to expose the underlying temporalis fascia.
Attention is then directed posteriorly where the greater wing of the sphenoid is removed using the cutting burr.
This can be performed with a combination of sizes of the burrs.
Once the posterior portion of the zygoma has been removed, the temporalis fascia can be separated from the lateral aspect of the greater wing of the sphenoid. This exposes the anterior portion of the greater wing of the sphenoid which is referred to as the trigone.
The goal here is to remove as much of the greater wing of the sphenoid bone as possible in order to assure maximal decompression of the posterior lateral orbital wall.
This can be performed with a combination of the cutting burrs as well as front biting Rongeurs.
In this area, the dura can be exposed to assure maximal removal of the greater wing of the sphenoid.
Hemostasis can be obtained if the bone bleeds with bone wax.
This is an additional patient demonstrating exposure of the trigone by dissecting the temporalis muscle from the underlying lateral aspect of the greater wing of the sphenoid.
This exposes the trigone and then the trigone can be removed with the cutting burr. This results in maximal removal of bone from the deep lateral wall of the orbit.
Fat removal can be performed by opening the periorbita inferior laterally.
The fat can be mobilized and the fat can be excised with the needle point cautery.
Bleeding from the fat can be controlled with monopolar and bipolar cautery.
In general, I tend to be conservative in fat removal. If the fat is easily mobilized I remove as much as possible, if it is more fibrotic, I tend to be less aggressive due to bleeding concerns.
The lateral cantholysis incision is closed with a single 4-0 Vicryl suture which engages the periorbita, followed by the inferior lateral tarsus, followed by the superior lateral tarsus, which again engages the periorbita.
Tying this suture placed the lateral canthus in good position.
The lateral canthotomy incision is then closed with a deep 4-0 vicryl suture followed by skin closure with the suture of your choice.
I still admit my decompressions post-operatively for one night to monitor vision.