Adjunctive transseptal corridor: Technique for endoscopic resection of orbital tumor

Abstract

The transnasal endoscopic approach is increasingly used for resection of tumors that are located inferiorly and medially within the orbit. However, this usually requires multiple-handed manipulations, which demand a second corridor for an assistant. Here, we introduce a simple transseptal corridor from the contra-nare, to facilitate assistant instrument maneuverability. This simple, minimally invasive skill greatly improves operation efficiency and deserves greater attention in endoscopic orbital surgery.

Transnasal endoscopic approaches to orbital lesions are used by increasing numbers of surgeons, because of their minimally invasive and adequate visualization.[1] However, these approaches are difficult for a single surgeon due to the challenge of orbital fat and muscle. Three- or four-handed manipulations are usually required, yet maneuverability is usually limited by the single nare, thus an adjunctive corridor for an assistant is valuable. Most techniques prefer a combined septectomy for medial mass resection[2] and a combined transmaxillary approach for inferior mass resection.[3] Here, we introduce two cases to illustrate a simple improvement for the transseptal technique. Specifically, our goal was to facilitate instrument maneuverability, especially for orbital cavernous venous malformation (CVM), one of the most common benign intraorbital malformations in adults. The advantages of this technique include its being minimally invasive and maintaining septal integrity, while greatly improving operation efficiency.

Patient Summaries

Case 1 (extraconal CVM in the right orbit): A 52-year-old female who complained of blurred vision in the right eye for 1 year was referred to our department by an ophthalmologist. Computed tomography (CT) revealed a right extraconal mass measuring 2.0 cm × 1.2 cm × 1.3 cm located medially with extension posterior to the orbital apex. Magnetic resonance imaging (MRI) demonstrated a heterogenous contrast-enhanced well-defined oval mass in the same location, indicating a CVM [Fig. 1]. Physical examination revealed a corrected right eye visual acuity of 1.3 (log magnification requirement scale).

Figure 1.

Preoperative MRI demonstrating orbital CVM in both cases. Case 1: (a1) axial section, T1 isointense; (b1) axial section, T2 hyperintense; (c1) sagittal section, T1 heterogenous contrast enhanced; demonstrating an extraconal CVM located medially in the right orbit. Case 2: (a2) axial section, T1 isointense; (b2) sagittal section, T2 hyperintense; (c2) coronal section, T1 heterogenous contrast enhanced; demonstrating an intraconal CVM located inferomedially in the left orbit. Red arrow in each part all indicated CVM

Case 2 (intraconal CVM in the left orbit): A 23-year-old female who complained of a slight swelling in her left eye for 3 months, without any blurred vision or diplopia. CT and MRI enhancement scanning revealed an inferomedial intraconal mass of about 1.4 cm × 1.1 cm × 0.8 cm, consistent with a CVM [Fig. 1].

As their lesions were medial to the optic nerve, both patients were scheduled for transnasal endoscopic surgery under general anesthesia.

Main Surgical Procedure

For case 1, an adjunctive transseptal corridor from the left nare, resecting extraconal CVM within the right orbit [details in Fig. 2 and Video 1]. For case 2, an adjunctive transseptal corridor from the right nare, resecting intraconal CVM within the left orbit [details in Fig. 3 and Video 2].

Figure 2.

Endoscopic view of case 1 during operation (extraconal CVM in the right orbit). Star: sphenoid sinus. Arrow in each part respectively indicated: (a) a Killian incision, (b) a second incision, (c) transseptal corridor, (d) retracting tumor with forceps, (e) a piece of perpendicular plate of ethmoid bone, (f) free middle turbinate mucosa layer

Figure 3.

Endoscopic view of case 2 during operation (intraconal CVM in the left orbit). MRM: medial rectus muscle. Star: tumor. Arrow in each part respectively indicated: (a) a Killian incision, (b) a second incision, (c) transseptal corridor, (d) retracting with hook, (e) separating with cotton pledget, (f) retracting tumor with forceps

1. First, to gain good exposure, a middle turbinectomy and ethmoidectomy were performed ipsilateral to the tumor; sphenoidotomy and/or maxillary antrostomy were added as needed. The lamina papyracea was fractured and removed according to the mass location, to achieve wide exposure of the intact periorbita. The free middle turbinate mucosa flap was reserved for later orbit rebuilding.

2. A Killian incision was made on the contralateral side of the septum [Figs. 2a and 3a], then separated along the submucoperichondria, at the intersection of the perpendicular plate of the ethmoid and anterior quadrangular cartilage. Detaching the linking, a piece of perpendicular plate of appropriate size and shape was harvested for later orbit rebuilding.

3. Another 5–10 mm mucosal incision was made on the ipsilateral side of the septum, at the corresponding position of the mass [Figs. 2b and 3b], thus a transseptal cross-corridor from the contralateral nare was made for an assistant [Figs. 2c and 3c], and used for retracting the tumor, suctioning bleeding, or drawing away fat/muscle [Figs. 2d and 3d-f].

4. With cooperating assistant retraction, the surgeon circumferentially freed the tumor from the surrounding fascia, mostly by blunt separating with cotton pledget, but occasionally by ablation. Muscles and optic nerves were always carefully protected.

5. After tumor removal, the orbit defect was rigidly reconstructed with the perpendicular plate of the ethmoid bone [Fig. 2e], then covered with a free middle turbinate mucosa layer [Fig. 2h]. The nasal cavity was gently packed with tela iodoformum and absorbable hemostatic material. The bilateral septal flaps were replaced and stitches were only needed for the Killian incision.

Results

CVMs were entirely removed in both cases. By three/four-handed manipulation, operations were completed efficiently and successfully. Both patients had uneventful postoperative recovery, with no obvious complications. For case 1, right-corrected visual acuity improved to 0.22 postoperative compared with 1.30 preoperative. In case 2, preoperative complaints of eye swelling resolved completely 1 week postoperative. At 1 year follow-up, endoscopic and MRI re-examination indicated complete recoveries for both patients, with normal eye morphology and function, septum integrity, and normal olfaction [Fig. 4].

Figure 4.

Endoscopic re-examination and MRI of each case during follow-up. (a and b) Endoscopic examination indicated medial orbit wall integrity and an intact septum 2 weeks and 5 weeks postoperative in case 1. (c) Endoscopic examination indicated inferomedial orbit wall integrity 3 months postoperative in case 2. (d–f) 4 months postoperative MRI showed complete tumor resection and a normal orbit structure in case 2. MOW(R): right medial orbital wall, S: septum, I-MOW(L): left inferomedial orbit wall

Discussion

Over recent years, transnasal endoscopy has become the favorable choice for medially and inferiorly located orbital masses.[4] However, unlike surgery for sinonasal disease, which can be generally manipulated by a single surgeon via a single nare, orbital management usually needs three/four-handed cooperation, and thus requires a second corridor for an assistant because of instrument movement restriction within a single nare.

To address this issue, various approaches have been tried, with the bi-naris approach favored. During this procedure, a septal window or partial septectomy at the mid-posterior of the septum is usually required, which may result in decreased smell and postoperative sinonasal morbidity.[2,5] To reduce such damage, Kim et al.[6] described a technique for endoscopic transseptal suture retraction. However, it was difficult with this technique to either make a suture deep in the nose or provide dynamic retraction via a tread. The transseptal technique has also been reported. For example, three methods of medial rectus muscle (MRM) retraction were described by Chen, including the four-handed transseptal technique.[7] In another case report, by Lao, a septal-preserving transseptal approach was described.[8] However, this technique has not yet been commonly recognized in the field. For example, it was not mentioned in a recent review of endoscopic endonasal approaches to intraconal orbital tumors.[9] In our experience, it is greatly helpful. Sharing its details here, with videos and figures, may facilitate its wider adoption.

Compared with the single-nare approach, the adjunctive transseptal corridor has many advantages. (1) With a transseptal corridor from the other nare, the assistant has adequate space for freedom of instrument movement. This greatly facilitates the assistant’s ability to cooperate, including dynamic tumor retracting, suctioning, and drawing fat/muscle during mass resection. (2) Preserving an intact septum with nearly no evidence of septal trauma. (3) Avoiding sacrifice of the contra-side middle and superior turbinate, without olfactory disturbance. (4) Simultaneously harvesting the perpendicular plate for orbital reconstruction. (5) If the patient is affected by septal deviation, this can be addressed simultaneously. (6) Most importantly, this technique is quite simple.

Transconjunctival and endonasal access are commonly used in orbital tumor resection, each has its own indications and limitations. Transconjunctival access is more suitable for anterior lesions, allows operation under direct view, simple and rapid. However, visualization is usually unsatisfactory, especially when the mass extends posteriorly to the apex. The endoscopic endonasal approach offers benefits including superior visualization and remitted skin incision; however, it is difficult to manipulate through a single nare. The combined transconjunctival and transnasal endoscopic approach leverages the benefits of each.[10] Now assistant cooperation through a transseptal corridor effectively solves problems, and additional transconjunctival access can often be avoided. In occasional cases, such as when the lesion is located extremely anterior, where it is difficult to make a wider angulation by a transseptal corridor, transconjunctival access may afford greater advantages.

The transnasal endoscopic approach is theoretically indicated for any mass size, especially large masses distending into the ethmoid sinus. This approach can also be adopted by oculofacial surgeons who are familiar with nasal cavity anatomy and proficient in endoscopic techniques. Of course, a collaboration between rhinologists and ophthalmologists may be optimal.

Postoperative complications like enophthalmos and diplopia may occur after endoscopic endonasal orbitotomy; rigid reconstruction of the medial orbital defect with a perpendicular plate can prevent such adverse events. However, it is also critical to attend to increased orbital pressure or pupillary abnormalities after reconstruction; if any abnormalities are noted, we may remove reconstruction when necessary. Of course, intraoperative attention and careful manipulations should always be focused constantly to avoid orbital apex syndrome.

As to septal perforation, because the incisions dislocate anteriorly and posteriorly, theoretically it is impossible. Even if a perforation is occasionally caused by severe deviation, it can be usually repaired by a local flap. In the case that it cannot be well repaired, small or posterior perforations cause few symptoms and generally need no treatment. Larger and anterior perforations contribute to nasal airflow disturbances, symptoms may include whistling, epistaxis, crusting, and pain which are needed for revsional rhinoplasty.

Overall, assistant cooperation by the transeptal technique is crucial for surgical success; retracting by the third hand greatly facilitates tumor separation and shortens the process. Besides CVMs, this technique is well suited to nearly all transnasal endoscopic orbital surgeries, because it just provides practical adjunctive access for multiple-handed surgical manipulation.

Contributions statement

Haihong Chen and Yang Yang designed the work; Haihong Chen, Yang Yang, and Lifang Shen performed the surgery; Yang Yang drafted the paper; Haihong Chen and Lifang Shen revised and approved the manuscript; and Haihong Chen agreed to be accountable for all aspects of the work.

Ethical approval

This study was approved by the ethical committee of The First Affiliated Hospital of Zhejiang University (protocol # 2023-0145) which exempted it from requiring individual patient consent. All procedures in this study were in line with the declaration for ethical consideration.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.