Lateral orbitotomy is the traditional approach for treating intraconal cavernous hemangioma; as this gives wide surgical exposure. However, it is a time-consuming major procedure that requires a visible skin incision, creation and reconstruction of a bone flap and a risk of trauma to the lateral rectus muscle with subsequent myopathy. Additionally, it is difficult to approach lesions that are medial to the optic nerve when using this technique. [6]
The transcranial approach is still used by neurosurgeons to approach the intraconal space despite the high rate of morbidity including visual loss, ptosis, orbital hemorrhage, postoperative subdural hematoma and meningitis. This technique should be reserved for lesions at the orbital apex or those with an intracranial extension. [7]
Since its introduction in 1980, transconjunctival anterior orbitotomy has been used to approach the intraconal space. It is not time-consuming, gives better cosmesis than lateral orbitotomy with a low risk of affecting the optic nerve, and it can be tailored according to the location of the lesion.
However, the transconjunctival orbitotomy technique is under-utilized because of the narrow space it presents, its inadequate exposure of deep intraconal lesions and subsequent postoperative complications. [8]
To achieve better results with the transconjunctival approach, the anterior border of the lesions should be close to the posterior pole of the globe; because deeper lesions close to the orbital apex will be masked by the orbital fat and therefore are more difficult to handle. [9]
In this study, we used the transconjunctival approach for excising intraconal cavernous hemangiomas where the masses were present lateral to, above, or below the optic nerve. All the tumors were successfully extracted with the aid of the cryoprobe that provided a good grip on the mass, facilitating removal without affecting the surrounding structures. In this study, three cases showed postoperative lateral rectus myopathy that improved spontaneously within six months, one case showed postoperative retrobulbar hemorrhage that did not compress the optic nerve and improved spontaneously, and four cases showed subconjunctival hemorrhage. Two cases presented preoperatively with drops in visual acuity; one of them showed improvement and one case did not improve after the surgery.
Jin et al. (2008) discussed several studies that had investigated transconjunctival access to the intraconal space; and Lazar et al. (1985) used the transconjunctival approach in 11 patients with intraconal cavernous hemangioma and reported complete, uncomplicated removal of all the tumors. Loewenstein et al. (1993) in a study that included 33 patients with cavernous hemangioma reported the same results as Lazar. [9]
Hayyam et al. (2005) reported complete removal of intraconal cavernous hemangiomas through a transconjunctival approach in 24 cases, but in this study one of the patients lost their vision due to optic nerve trauma. [10]
Xiang et al. (2008) performed transconjunctival cryo-extraction of 36 intraconal lesions; 35 of these lesions were cavernous hemangioma and one of them was diagnosed pathologically as neurilemoma. They reported that this approach is safe; less traumatizing and less time-consuming than other techniques. [11]
Renbeing et al. (2013) reported that the transconjunctival approach is nearly equal to lateral orbitotomy in terms of the improvement of proptosis and rate of complications with decreased operative time. [12]
Cryo-extraction is best used in tumors and cysts that contain fluid (blood or other fluids), rather than in solid tumors, because freezing occurs on the surface of the tumor as well as in the stroma and fluid or blood inside. Consequently, the outer and inner ice balls allow a strong grip to be applied by the probe, which makes cavernous hemangiomas ideal for this approach. [13]
Gdal-On et al. used cryo-assisted extraction of intraconal hemangiomas and reported easy extraction in lesions that touched the globe, but they did not recommend this approach in deeper lesions that reached the orbital apex; as this technique may endanger the apical structures. [14]
Tsirbas et al. (2005) reported that the use of the cryoprobe for the removal of intraconal tumors through the transconjunctival approach decreased the rate of complications associated with the surgery [15].
Castelnuovo et al. (2019) used the cryoprobe to extract two orbital cavernous hemangiomas transnasally and reported that the cryoprobes represent an adjunctive tool in the extraction of fluid-filled intraorbital lesions. [16]
One of the limitations of this approach is the narrow working space, and therefore the lesion’s anterior margin should be adjacent to the globe for easy, safe, handling and removal of the tumors. However, more posterior lesions will be more difficult to manipulate and will be masked by orbital fat. Use of the standard retinal cryoprobe provides a good grip on the mass. even in deep lesions, without affecting the surrounding structures .[16]
In this study, we found that the use of a cryoprobe for tumor extraction helps with the removal of deeper lesions that are not touching the back of the globe after exposure of a sufficient portion of the mass to provide a good grip and after retraction of the surrounding fat. Retrobulbar hemorrhage and rupture of the angioma are possible complications and should be avoided through good intraoperative hemostasis and gentle dissection of the mass, respectively.