https://orcid.org/0009-0005-8728-2024
Abstract
Access to far-lateral frontal sinus lesions remains challenging, even after a Draf III procedure. We describe an endoscopic orbital transposition approach combined with 3D vascularized flap reconstruction for a laterally located frontal sinus cyst. After completion of the Draf III procedure, the orbit was mobilized laterally to access the cyst. Exposed bone surfaces were reconstructed using three vascularized flaps: a posterior pedicled lamina papyracea flap, a Superior Lateral Anterior Pedicled flap, and bilateral septoturbinal flaps. This technique provides direct access to far-lateral frontal sinus lesions while enabling broad vascularized coverage of exposed bone surfaces and may help reduce postoperative restenosis.
Introduction
Despite advances in endoscopic frontal sinus surgery, reliable access to the far-lateral frontal sinus remains challenging. Although the Draf III procedure provides wide exposure of the frontal sinus floor, lesions lateral to the orbital wall are often difficult to reach through conventional endonasal corridors [1]. Orbital transposition expands the endonasal corridor by mobilizing the medial orbital contents, thereby enabling direct access to the lateral frontal sinus [2].
Another challenge in extended frontal sinus surgery is postoperative restenosis associated with exposed bone after drilling. Durable mucosalization and long-term patency depend on coverage of exposed bone with vascularized tissue [3]. We describe orbital transposition combined with a multidirectional “three-dimensional” flap reconstruction strategy using three vascularized flaps: the previously described septoturbinal and superior lateral anterior pedicled (SLAP) flaps, and a novel posterior pedicled lamina papyracea (PPLP) flap [4, 5].
Case report
Case presentation
A 74-year-old man presented with recurrent swelling and tenderness of the left forehead and upper eyelid (Fig. 1A). Computed tomography revealed a laterally located frontal sinus cyst with infection and subcutaneous abscess formation (Fig. 1B). Despite prior endoscopic frontal sinus surgery, including extended frontal sinusotomy, the lesion remained inadequately accessible because of its far-lateral location. Orbital transposition was therefore selected to achieve direct access and allow definitive drainage and reconstruction. Written informed consent was obtained from the patient. The study was conducted in accordance with the Declaration of Helsinki and approved by the institutional review board (approval number: 81-082).
Initial clinical presentation. (A) Swelling and erythema of the left upper eyelid associated with pain. (B) CT demonstrating a cystic lesion occupying the lateral aspect of the left frontal sinus.
Surgical approach
Surgery was performed under general anesthesia. Intraoperative imaging guidance was provided using a StealthStation system (Medtronic). A Draf IIb procedure was performed on the left side during a previous surgery (Fig. 2A). To perform the Draf III procedure, bilateral septoturbinal flaps were created as follows: an inverted U-shaped incision was made in the axilla of the middle turbinate, extending across the nasal septum (Fig. 2B). Each flap was elevated in the subperiosteal plane from anterior to posterior until the first olfactory fiber was reached. The Draf III procedure was completed by creating a septal window and performing bilateral drilling through the frontal beak and intersinus septum, with careful preservation of the bilateral olfactory fibers (Fig. 2C). Despite completion of the Draf III procedure, access to the laterally located frontal sinus cyst could not be achieved. Therefore, we proceeded with a left-sided orbital transposition approach. The PPLP flap was created as follows. A vertical mucosal incision was made posterior to the lacrimal bone. A horizontal incision was then made along the orbital floor, and another horizontal incision was created superiorly at the level of the frontal recess to outline the flap (Fig. 2D). Subsequently, a posteriorly based flap was designed and carefully elevated in the subperiosteal plane to expose the bone of the lamina papyracea (Fig. 2E). This vascularized pedicle flap was reflected posteriorly and preserved. Following flap elevation, the lamina papyracea was drilled to expose the orbital periosteum. The orbit was then gently mobilized laterally in the subperiosteal plane to access the far lateral wall of the frontal sinus (Fig. 2F).
Draf III and orbital transposition to access the far-lateral frontal sinus. (A) Endoscopic view of the left nasal cavity showing the previous Draf IIb opening. (B) Right nasal endoscopic view showing the inverted U-shaped incision for septoturbinal flap creation. (C) After bilateral septoturbinal flap creation and septal window formation, the Draf III procedure was completed. (D) A vertical incision was made posterior to the lacrimal bone, and horizontal incisions were made at the respective levels of the orbital floor and the frontal recess to outline the posteriorly based PPLP flap. (E) The PPLP flap was elevated posteriorly to expose the bone of the lamina papyracea. (F) After removal of the lamina papyracea, the orbital periosteum was exposed and mobilized laterally, completing the orbital transposition step. Rt.: right; Lt.: left; NS: nasal septum; IT: inferior turbinate; MT: middle turbinate; FS: frontal sinus; LP: lamina papyracea; PO: periorbita; OR: orbital roof; flap 1: septoturbinal flap; flap 2: PPLP flap.
Bone from the medial orbital roof was first removed to access the cyst located in the lateral frontal sinus. The cyst was then incised, the purulent material was aspirated, and the cavity was irrigated (Fig. 3A). Subsequently, the PPLP flap was rotated superiorly to cover the anterolateral surface of the anterior skull base (Fig. 3B). To cover the exposed bone of the frontal beak, a SLAP flap was created as follows: a horizontal incision was made from the anterior edge of the inferior turbinate, and a second horizontal incision was made at the attachment of the uncinate process (Fig. 3C). The flap was rotated superiorly to cover the exposed frontal beak (Fig. 3D). The previously created septoturbinal flaps were rotated superiorly to cover the anteromedial surface of the anterior skull base. Each flap was strategically positioned to ensure coverage in the anterior, posteromedial, and posterolateral directions, thereby creating a 3D flap configuration (Fig. 3E). After confirming wide communication between the cyst cavity and left frontal sinus (Fig. 3F), the procedure was completed. The key steps of the procedure are shown in Supplementary Video 1.
Cyst marsupialization and 3D flap reconstruction. (A) Bone of the medial orbital roof was removed, after which the cyst was subsequently opened, drained, and irrigated. (B) The PPLP flap was then rotated superiorly to cover the anterolateral skull base. (C) The SLAP flap was harvested from the left inferior turbinate. (D) The SLAP flap was rotated superiorly toward the frontal sinus to cover the drilled area of the frontal beak. (E) The exposed bony surfaces were covered with three flaps. The anteromedial skull base was covered with a septoturbinal flap, the anterolateral skull base with a PPLP flap, and the frontal beak with the SLAP flap. (F) The cyst cavity is widely opened into the left frontal sinus, confirming adequate drainage and a patent frontal sinus communication. Rt.: right; Lt.: left; NS: nasal septum; IT: inferior turbinate; MT: middle turbinate; FS: frontal sinus; PO: periorbita; FC: frontal sinus cyst; flap 1: septoturbinal flap; flap 2: PPLP flap; flap 3: SLAP flap.
Results
The patient’s postoperative recovery was uneventful. At 4 months, endoscopy demonstrated satisfactory mucosal healing with widely patent communication between the cyst cavity and frontal sinus (Fig. 4A), and CT confirmed a well-aerated frontal sinus without obstruction (Fig. 4B). At the 18-month follow-up, the patient remained asymptomatic, with no recurrence or restenosis.
Endoscopic findings 4 months postoperatively. (A) Endoscopic findings at 4 months postoperatively demonstrated stable communication between the cyst cavity and the frontal sinus. (B) CT at 4 months postoperatively demonstrated a well-aerated frontal sinus. FC: frontal sinus cyst.
Discussion
Although the Draf III procedure provides wide frontal sinus access, far-lateral lesions may remain difficult to reach. Cadaveric studies have shown that exposure beyond the midorbital point is achieved in only a small proportion of cases [1]. Orbital transposition can overcome this limitation by mobilizing the medial orbital wall and periorbita to expand the endonasal corridor [2].
Postoperative restenosis is another concern after extended frontal sinus surgery, particularly when large areas of bone remain exposed. Vascularized mucosal flaps promote mucosalization and may reduce granulation and neo-osteogenesis [3].
We present a novel vascularized mucosal flap, the PPLP flap, based on the periosteum overlying the lamina papyracea and pedicled posteriorly toward the ethmoidal roof. This flap provides coverage of the posterior and lateral aspects of the frontal skull base, which are difficult to mucosalize using conventional techniques. To our knowledge, no previous study has described a mucosal flap from this specific location in the Draf III procedure. Combined with the previously described SLAP and septoturbinal flaps, the PPLP flap enabled vascularized coverage of exposed bone surfaces in three directions, which we define as “three-dimensional flap reconstruction.” A schematic representation is shown in Fig. 5. This strategy may reduce postoperative restenosis associated with granulation, fibrosis, and neo-osteogenesis.
Three-dimensional flap reconstruction. (A) The PPLP flap covered the anterolateral surface of the anterior skull base. (B) The SLAP flap covered the exposed frontal beak. (C) Incision design for the septoturbinal flap, which was used to cover the anteromedial skull base. NS: nasal septum; MT: middle turbinate; OC: olfactory cleft.
Although this report represents a single application, the combined use of orbital transposition and 3D flap reconstruction may provide a practical surgical strategy for complex far-lateral frontal sinus lesions and contribute to improved mucosal healing and reduced restenosis.
Acknowledgements
The authors thank the nursing staff and surgical assistants at Hamamatsu University School of Medicine for their dedicated support during postoperative patient care. We also appreciate the artwork provided by MEDICAL FIG., a service of Medical Education, Inc.
Conflicts of interest
The authors declare no conflicts of interest.
Funding
None declared.
