2016 Section 5 Green Book

Endoscopic OCH resection

Boston, MA. A common 25-point questionnaire was sent to 6 highly experienced orbital surgery centers on 3 continents (North America, n = 3; Europe, n = 2; and South America, n = 1). This study had extremely rigid inclusion criteria and accepted only patients who underwent a strictly endoscopic resection of a histopathologically proven OCH, although external methods of medial rectus retraction were permit- ted. The questionnaires covered specific elements of the preoperative workup, intraoperative techniques, and post- operative outcomes. All data was derived from primary patient records by the operating surgical team. The final data from each center was compiled and analyzed to quali- tatively identify points of both consensus and variability in techniques. Results Data from a total of 23 patients who underwent an endo- scopic endonasal resection of an OCH were collected. The population was comprised of 10 (43.5%) males and 13 (56.5%) females with a mean ± standard deviation (SD) age of 50.9 ± 13.5 years. Fifteen (65.2%) lesions were lo- cated on the right side, and 8 (34.8%) were located on the left side. The majority of lesions were located within the in- traconal space (60.9%) and the mean follow-up time was 25.3 ± 23.0 months. The most common presenting symptom was visual im- pairment (65.2%) followed by proptosis (34.8%). Nearly all patients underwent both computed tomography (CT) (100.0%) and magnetic resonance imaging (MRI) (95.7%) as part of the preoperative workup, whereas only 1 patient (4.4%) underwent preoperative angiography (Table 1). The mean surgical time was 150.7 ± 75.0 minutes with a mean blood loss of 82.7 ± 49.6 mL. Eleven cases were per- formed as a team approach including otolaryngology with ophthalmology (26.1%) or neurosurgery (21.7%). The most common approach utilized a single nostril (69.6%). Binarial approaches (26.1%) were used exclusively in the setting of intraconal lesions. Among the intraconal le- sions, a 4-handed, binarial approach was utilized in 37.5% of cases in contrast to a strictly 2-handed or 3-handed unilateral approach for patients with extraconal lesions (Fig. 1, Table 2). Bipolar cautery was used for hemostasis in 56.5% of cases, whereas monopolar cautery was avoided in all cases. The majority of cases (73.9%) achieved a complete re- section and did not undergo any subsequent orbital recon- struction. Among orbits that were reconstructed, 83.3% utilized a mucosal graft, whereas 16.7% used fascia lata (Table 3). Similarly, the majority of postoperative outcomes were favorable, with 78.3% of cases resulting in a sym- metric eye position. Immediate preservation of binocular vision was achieved in 60.9% of patients (Table 4). All but 1 patient with postoperative diplopia resolved within 2 to 3 months. The etiology of diplopia for this patient with was thought to be inadvertent injury to the inferior rectus muscle.

matured from technique papers to larger multicenter out- come studies. 11 A similar rigor must be applied to the endo- scopic orbital literature in order to expand the knowledge base in this, still nascent, field. Orbital cavernous hemangioma (OCH) represents an ideal index lesion to study for a variety of reasons. First, it represents 1 of the most common tumors of the orbit ac- counting for 5% to 15% of orbital masses. Although OCHs have a predilection for the lateral intraconal space, likely due to a mirroring of ophthalmic arterial vasculature, they may be found throughout the orbit including the medial in- traconal and extraconal spaces, as well as the optic canal. 12 Second, the technical complexity of endoscopic dissection is facilitated by the presence of a robust fibrous capsule. Al- though these lesions tend not to infiltrate into local tissue, they are capable of incorporating adjacent blood vessels and nerves into their capsule as they expand. 13 Histologi- cally, OCHs demonstrate features of slow-growing venous lesions with mature cellular components that do not tend toward dysplasia or hypercellularity. Based on the classifi- cation of the International Society for the Study of Vascular Anomalies (ISSVA), these lesions should be characterized as slow-flow cavernous venous malformations. Clinically, OCHs are slow growing with a radiologic growth rate of 10% to 15% per year, resulting in displacement of the globe (axial proptosis for intraconal lesions, nonaxial dis- placement of the globe for extraconal masses) and, later, visual loss. Expansion is thought to result from a cycle of intravascular clot formation related to vascular stasis, which leads to thrombosis, endothelial cell proliferation, and subsequent recanalization into multiple clefts and vas- cular channels. 14 Because of the slow growth rate, surgi- cal resection is indicated for symptomatic lesions, whereas smaller, asymptomatic lesions may be observed. The gen- eral goal of surgical management is definitive resection be- cause the fate of lesions after partial resection is not well established in the literature. 14 The purpose of this study was to create a composite of the collective global experience on purely endoscopic en- donasal resection of OCHs from primary records. By com- bining the experience of multiple international centers on addressing a single type of pathology, we have been able to generate a moderate series of an otherwise rare pro- cedure. This, in turn, helps to eliminate the confounders inherently associated with studies that group a range of het- erogeneous lesions in order to generate a larger number of cases. Through this effort, our international consortium en- deavors to develop some basic recommendations that may be extrapolated to other types of lesions and can serve as a foundation for further growth in this field. Materials and methods This was an Institutional Review Board (IRB)-approved, multi-institutional, international, retrospective study of techniques and outcomes in endoscopic orbital surgery, and was performed at the Massachusetts Eye and Ear Infirmary,

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