Transorbital Endoscopic Approach to the Foramen Rotundum for Infraorbital Nerve Stripping.

PURPOSE: To develop and evaluate a transorbital endoscopic approach to the foramen rotundum to excise the maxillary nerve and infraorbital nerve branch. METHODS: Cadaveric dissection study of 10 cadaver heads (20 orbits). This technique is predicated upon 1) an inferior orbital fissure release to facilitate access to the orbital apex and 2) the removal of the posterior maxillary wall to enter the pterygopalatine fossa (PPF). Angulations along the infraorbital nerve were quantified as follows: the first angulation was measured between the orbitomaxillary segment within the orbital floor and the pterygopalatine segment suspended within the PPF, while the second angulation was taken between the pterygopalatine segment and maxillary nerve as it exited the foramen rotundum. With refinement of the technique, the minimum amount of posterior maxillary wall removal was quantified in the final 5 cadaver heads (10 orbits). RESULTS: The mean distance from the inferior orbital rim to the foramen rotundum was 45.55 ± 3.24 mm. The first angulation of the infraorbital nerve was 133.10 ± 16.28 degrees, and the second angulation was 124.95 ± 18.01 degrees. The minimum posterior maxillary wall removal to reach the PPF was 11.10 ± 2.56 mm (vertical) and 11.10 ± 2.08 mm (horizontal). CONCLUSIONS: The transorbital endoscopic approach to an en bloc resection of the infraorbital nerve branch up to its maxillary nerve origin provides a pathway to the PPF. This is relevant for nerve stripping in the context of perineural spread. Other applications include access to the superior portion of the PPF in selective biopsy cases or in concurrent orbital pathology.

The effect of injection of 1:100 000 adrenaline solution in the pterygopalatine fossa on intra-operative bleeding during endoscopic sinonasal surgical procedures in chronic sinusitis: a blinded clinical trial.

OBJECTIVE: Rhinosinusitis is one of the most common reasons for a visit to otolaryngology clinics. Some patients are candidates for sinus surgery. Infiltration of 1:100 000 adrenaline in the pterygopalatine fossa was studied, with the aim of evaluating the effect on bleeding in the surgical field. METHODS: This double-blind clinical trial was conducted in 2021-2022 on 40 candidates for endoscopic sinus surgery. For each patient, one side of the pterygopalatine fossa was randomly selected to be infiltrated with a vasoconstrictor. Surgical field bleeding on each side was evaluated. RESULTS: Blood loss was 35.8 ± 20.9 ml in the study group and 38.4 ± 23.7 ml for the control group, with no statistically significant difference between groups (p = 0.49). In addition, there was no difference between the two groups in terms of the surgical field based on Boezaart scores. CONCLUSION: Although there are some recommendations on the usage of vasoconstrictors via the pterygopalatine foramen, debate remains.

Transorbital Endoscopic Approach to the Pterygopalatine Fossa: A Less Invasive Alternative to Traditional Access.

PURPOSE: The purpose of this article and accompanying video is to demonstrate a transorbital endoscopic approach for accessing the pterygopalatine fossa (PPF). This technique does not require a skin incision, avoids dissection of critical neurovascular structures, and utilizes a comparatively small osteotomy. The 2 cases presented in this article highlight the utility of a transorbital endoscopic approach for accessing an anatomic region that has traditionally required more invasive techniques to reach. METHODS: Description of surgical technique with 2 illustrative clinical cases and accompanying surgical video. RESULTS: Surgical technique: A trans-conjunctival approach is taken to the inferior orbital rim, and a subperiosteal dissection is propagated posteriorly. The bone of the posterior orbital floor is then deroofed, and the superior portion of the posterior wall of the maxillary sinus is removed, allowing access to the PPF for an incisional biopsy. CASE: A 76-year-old male with a history of left cheek squamous cell carcinoma presented with progressive V2 paresthesia and an abnormally enhancing lesion in the left PPF on MRI. CASE: A 58-year-old male with no significant medical history presented with left facial numbness (V1-V3), ptosis, an abduction deficit, and decreased hearing. Contrast-enhanced MRI demonstrated an abnormally enhanced lesion in the left PPF extending to Meckel's cave.The transorbital approach described was used to successfully obtain a diagnostic biopsy in both cases. CONCLUSIONS: These cases highlight the utility of a transorbital endoscopic approach to the PPF as a less morbid alternative to traditional access. Patient selection is key to identifying appropriate cases.

An Intraosseous Pterygopalatine Fossa Dural Arteriovenous Fistula.

Intraosseous dural arteriovenous fistulas (DAVFs) are distinct in that the fistula is located within the bone rather than the dura through which the dural vessels pass. It has been stated that only fistulas within marrow should be considered as intraosseous DAVFs rather than DAVFs with traditional angioarchitecture that erode into bone or are located within a bony foramen. The ambiguity in the definition may have contributed to the oversight and scarcity of relevant cases reported in the literature. Three- or four-dimensional digital subtraction angiography is useful for determining the location of the fistula and developing treatment plans. We present an intraosseous DAVF around the pterygopalatine fossa using a transvenous approach.

Drainage of a Pterygopalatine Fossa Abscess With Chronic Sinusitis via an Endoscopic Nasal Approach.

The pterygopalatine fossa is a clinically inaccessible space deep in the face, and reports of pterygopalatine fossa abscesses are rare. The authors present the case of a 63-year-old woman presenting with a severe headache owing to an abscess involving the pterygopalatine fossa. On a computed tomography scan, inflammation of the right pterygopalatine fossa associated with right maxillary sinusitis and periapical inflammation and a cystic lesion around the tooth were observed. After administering appropriate antibiotics, the headache improved considerably, and endoscopic nasal surgery resulted in adequate abscess drainage. To the authors' knowledge, this case study is one of the few reporting the successful treatment of an abscess in the pterygopalatine fossa through an endoscopic transnasal approach.

Endoscopic-assisted en-bloc pterygomaxillectomy: Identifying an efficient and safe location for the pterygoid osteotomy.

BACKGROUND: For aggressive maxillary sinus and pterygopalatine fossa (PPF) tumors, an en-bloc pterygomaxillectomy may be indicated. METHODS: Five head specimens were used to study the feasibility of an en-bloc pterygomaxillectomy. Eighty-five non-pathological CT scans were used to compare the superior edge of the inferior turbinate (IT) and the middle turbinate tail (MT) as landmarks for the pterygoid osteotomy. RESULTS: Through a combined sublabial-subperiosteal incision and transoral route, a mid-sagittal osteotomy through the hard palate and an axial osteotomy below the infraorbital foramen were performed. For the endoscopic pterygoid osteotomy, an infra-vidian transpterygoid approach was performed, subsequently removing the pterygomaxillectomy en-bloc. As landmarks, the osteotomies at the level of the MT tail and IT resected the pterygoid plates completely, but the IT osteotomy was further away from the vidian canal (7.5 vs. 6 mm). CONCLUSIONS: The endoscopic-assisted en-bloc pterygomaxillectomy is feasible. The IT landmark is safe and ensures complete resection of the pterygoid plates.

A Rare Instance of Pterygopalatine Fossa Tumor With Hearing Loss as the Main Complaint.

Pterygopalatine schwannomas are rare tumors which usually cause the symptoms of the traffic area by the tumors in the pterygopalatine fossa which is difficult to resection. This paper presents 1 rare case of pterygopalatine fossa tumor with hearing loss as the main complaint treated by total resection through the endoscopic endonasal approach.

Infra-Temporal and Pterygo-Palatine Fossae Tumors: A Frontier in Endoscopic Endonasal Surgery-Description of the Surgical Anatomy of the Approach and Report of Illustrative Cases.

Infratemporal and pterygopalatine fossae (ITF and PPF) represent two complex paramedian skull base areas, which can be defined as jewelry boxes, containing a large number of neurovascular and osteomuscular structures of primary importance. They are in close communication with many craniofacial areas, such as nasal/paranasal sinuses, orbit, middle cranial fossa, and oral cavities. Therefore, they can be involved by tumoral, infective or inflammatory lesions spreading from these spaces. Moreover, they can be the primary site of the development of some primitive tumors. For the deep-seated location of ITF and PPF lesions and their close relationship with the surrounding functional neuro-vascular structures, their surgery represents a challenge. In the last decades, the introduction of the endoscope in skull base surgery has favored the development of an innovative anterior endonasal approach for ITF and PPF tumors: the transmaxillary-pterygoid, which gives a direct and straightforward route for these areas. It has demonstrated that it is effective and safe for the treatment of a large number of benign and malignant neoplasms, located in these fossae, avoiding extensive bone drilling, soft tissue demolition, possibly unaesthetic scars, and reducing the risk of neurological deficits. However, some limits, especially for vascular tumors or lesions with lateral extension, are still present. Based on the experience of our multidisciplinary team, we present our operative technique, surgical indications, and pre- and post-operative management protocol for patients with ITF and PPF tumors.

Endoscopic Endonasal Approach to the Pterygopalatine Fossa and Infratemporal Fossa: Comparison of the Prelacrimal and Denker's Corridors.

BACKGROUND: Both the endoscopic transnasal Denker's and prelacrimal approaches provide surgical access to the pterygopalatine fossa (PPF) and infratemporal fossa (ITF). OBJECTIVES: This study compares the potential maximum exposure of the PPF and ITF and quantifies the difference in surgical freedom via endoscopic Denker's and prelacrimal approaches. METHODS: Six cadaveric specimens (12 sides) were dissected using a prelacrimal approach on one side and an endoscopic Denker's approach on the contralateral side. The contents of the PPF and ITF were sequentially exposed. Surgical freedom for each corridor was subsequently calculated. RESULTS: This study confirms that both the prelacrimal and Denker's approaches provide adequate exposure of the PPF and ITF. The maximum exposure boundaries were similar for both approaches, including the middle cranial fossa superiorly, floor of the maxillary sinus inferiorly, zygomatic arch and temporomandibular joint laterally, and post-styloid space posteriorly. However, the data revealed a statistically significant difference (p < 0.05) regarding the surgical freedom of the prelacrimal (388.17 ± 32.86 mm2) and the endoscopic Denker's approaches (906.35 ± 38.38 mm2). CONCLUSION: When compared with an endoscopic Denker's approach, a prelacrimal approach seems to achieve a similar extent of exposure (ie, visualization) of the PPF and ITF. Nonetheless, the endoscopic Denker's approach offers superior surgical freedom; thus, it is preferred for the management of complex lesions which requires increased instrument maneuverability with a 3- or 4-handed technique.

The Endoscopic Trans-Sinusoidal Trans-Pterygopalatine Route to the Foramen Rotundum Approach in Trigeminal Neuralgia Treatment.

AIM: To describe a new, minimally invasive, and safe access to foramen rotundum via the endoscopic endonasal trans-sinusoidal route for trigeminal nerve blockage. MATERIAL AND METHODS: We studied 5 fresh cadavers bilaterally, and 10 pterygopalatine fossae and maxillary nerves using the endoscopic endonasal trans-sinusoidal trans-pterygopalatine approach. RESULTS: The proposed approach enabled the maxillary nerve to be visualized after revealing the foramen rotundum with the help of some craniometric measurements. Distance between sphenoid sinus lateral wall and maxillary sinus posterior wall was measured. This measurement was found to be an important triangulation point to determine the location of the entrance to the pterygopalatine fossa. The distance between the foramen rotundum and the sphenopalatine artery was found to be significant. The foramen rotundum diameter was calculated, and the maxillary nerve was found to be situated inferolateral to the foramen rotundum. Therefore, the safe entry zone was determined superomedially. No significant difference was found between male and female and the right and left nostrils. CONCLUSION: Various surgical procedures have been applied to treat drug-resistant trigeminal neuralgia. Nevertheless, their cure rates remain less than anticipated. Recurrences up to 30% have been reported in the literature. In this study, the endoscopic endonasal transmaxillary trans-pterygopalatine route offers a new perspective on the foramen rotundum approach and provides a panoramic and safe view in previously high-risk percutaneous interventions.

Endoscopic Endonasal Removal of Stray Bullets in the Fossa Pterygopalatine in Innocent Young Bystanders of Conflicts in Somalia in a Period of Six Months.

ABSTRACT: In Somalia, which is located in the horn of Africa, a fragile and insecure state structure allowed the strengthening of terrorist groups provoking armed conflicts. Stray bullet injuries can be defined as an accidental bullet wound caused by an anonymous attacker and are usually associated with celebratory gunfire or urban violence. The anatomy of the pterygopalatine fossa (PPF) is complex and penetrating foreign body injuries pose even a greater challenge for the surgeon to operate in this area. Endoscopic approaches facilitate the removal of foreign bodies from the paranasal sinuses, orbital cavity, and aerodigestive system, minimizing potential risks. This study presents a series of removal of stray bullets found in the PPF, as a result of urban violence in Somalia in a period of 6 months. Patient demographics, foreign body origin, treatment modalities, and surgery details were evaluated and assessed. All patients were male and aged 16, 2, and 24 years, respectively. The surgeries were quite straightforward with surgery times recorded as 25, 44, and 22 minutes, respectively. The endoscopic endonasal approach proved to provide safe and sufficient access for removal. Surprisingly, even the foreign body in the PPF of a 2-year-old patient could be removed with an endoscopic endonasal approach and did not require an external approach. The management of foreign body removal in the PPF is challenging due to the potential risks of iatrogenic vascular and nervous tissue injury. The endoscopic endonasal approach for removal proved efficient in 3 cases regardless of age and anatomical dimensions.

A novel landmark for endonasal surgery of the pterygopalatine fossa and inferior orbital fissure: The orbito-pterygo-sphenoidal ligament.

The pterygopalatine fossa contains a dense and complex array of neurovascular structures vulnerable to accidental surgical injury. This study aims to describe a novel landmark, the orbito-pterygo-sphenoidal ligament (OPSL), and implications of this structure for surgery in the pterygopalatine fossa and the inferior orbital fissure. Six cadaveric specimens (12 sides) were dissected using an endonasal approach to expose the periosteal layers associated with the pterygopalatine fossa and orbit. The thickened triangular-shaped ligament at their confluence was termed the OPSL. Dimensions of its lateral, inferior, and medial borders were measured, and their anatomical relationships defined. The pterygopalatine ganglion and the maxillary nerve lie immediately inferior and deep into the OPSL. The superior aspect of the posterior nasoseptal artery and nerve are covered by the medial OPSL. The lateral and inferior borders of the OPSL are contiguous with the periorbita and the periosteum of the pterygopalatine fossa, respectively. Along the medial border of the ligament, the openings of the palatovaginal fissure, vidian canal, and foramen rotundum were sequentially identified in a medial to lateral trajectory. The length of the lateral, inferior, and medial borders of the triangular OPSL were 13.25 ± 0.62, 14.25 ± 0.45, and 12.08 ± 0.90 mm, respectively. The OPSL is a thick, triangular-shaped fascial confluence, which may serve as a landmark for procedures within the pterygopalatine fossa and the inferior orbital fissure.

Pterygopalatine Fossa: Microsurgical Anatomy and its Relevance for Skull Base Surgery

Introduction The purpose of this study was to define the anatomical relationships of the pterygopalatine fossa (PPF) and its operative implications in skull base surgical approaches. Methods Ten cadaveric heads were dissected at the Dianne and M Gazi Yasargil Educational Center MicrosurgicaLaboratory, in Little Rock, AK, USA. The PPF was exposed through an extended dissection with mandible and pterygoid plate removal. Results The PPF has the shape of an inverted cone. Its boundaries are the pterygomaxillary fissure; themaxilla, anteriorly; themedial plate of the pterygoid process, and greater wing of the sphenoid process, posteriorly; the palatine bone,medially; and the body of the sphenoid process, superiorly. Its contents are the maxillary division of the trigeminal nerve and its branches; the pterygopalatine ganglion; the pterygopalatine portion of the maxillary artery (MA) and its branches; and the venous network. Differential diagnosis of PPF masses includes perineural tumoral extension along the maxillary nerve, schwannomas, neurofibromas, angiofibromas, hemangiomas, and ectopic salivary gland tissue. Transmaxillary and transpalatal approaches require extensive resection of bony structures and are narrow in the deeper part of the approach, impairing the surgical vision and maneuverability. Endoscopic surgery solves this problem, bringing the light source to the center of the surgical field, allowing proper visualization of the surgical field, extreme close-ups, and different view angles. Conclusion We provide detailed information on the fossa's boundaries, intercommunications with adjacent structures, anatomy of the maxillary artery, and its variations. It is discussed in the context of clinical affections and surgical approaches of this specific region, including pterygomaxillary disjunction and skull base tumors.

Endoscopic Endonasal Surgery for Resection of a Pterygopalatine Fossa Malignant Peripheral Nerve Sheath Tumor: 2-Dimensional Operative Video.

The pterygopalatine fossa (PPF) is an inverted, pyramid-shaped space immediately behind the posterior wall of the maxillary sinus, and lesions arising here include juvenile angiofibromas, schwannomas, and, in exceptionally rare cases, malignant peripheral nerve sheath tumors.1,2 Surgical access to the PPF is challenging and has been historically achieved via an open transmaxillary approach associated with facial scaring/deformity as well as potential injury to facial and infraorbital nerve branches.3 We present the case of a 67-year-old woman with facial numbness secondary to a presumed trigeminal schwannoma in the right PPF on magnetic resonance imaging. This surgical video highlights the key stages in performing an endoscopic endonasal excision of a PPF tumor. We start with a wide medial maxillary antrostomy, mobilization of the inferior turbinate, ethmoidectomy, and sphenoidotomy. The posterior wall of the maxillary sinus is then lifted off the anterior aspect of the tumor. The soft tissue attachment medial to the tumor containing the sphenopalatine artery is then cauterized and divided. This is followed by circumferential blunt dissection of the tumor until it is sufficiently mobile to remove in a piecemeal fashion. The PPF is then examined for any residual tumor and any bleeding from the maxillary artery within the fat pad. Hemostasis and reattachment of the inferior turbinate into the lateral nasal wall is demonstrated. The patient did not have any new deficits postoperatively, but histology indicated a malignant peripheral nerve sheath tumor and she underwent postoperative proton beam therapy. Postoperative surveillance magnetic resonance imaging at 14 months showed no tumor recurrence. The patient consented to the procedure in a standard fashion (Video 1).

Extradural anterior temporal fossa approach to the paranasal sinuses, nasal cavities through the anterolateral and anteromedial triangles: Combined microscopic and endoscopic strategy.

OBJECTIVE: To demonstrate the utility and limitations of the extradural endoscopic-assisted anterior temporal fossa approach to the pterygopalatine fossa (PPF), infratemporal fossa (ITF), paranasal sinuses (PS), parapharyngeal region (PPR), nasal cavities (NC), epipharynx (EP), and clivus. METHODS: A frontotemporal orbitozygomatic craniotomy is performed. The dura is elevated from the cavernous sinus (CS). The anterior temporal fossa floor is drilled. Foramen rotundum and ovale are opened. The PPF is exposed and the lateral margin of inferior orbital fissure (IOF) is removed. The anterolateral triangle (ALT) is drilled and the vidian nerve (VN) is exposed. Drilling between the maxillary nerve (V2) and the VN provides access to the sphenoid sinus (SphS). The medial pterygoid plate is drilled exposing the EP. The maxillary sinus (MaxS) is opened anterior to the PPF. V2 is transposed laterally to enlarge the anteriomedial triangle (AMT). The orbital muscle of Muller is removed as well as the medial margin of the IOF, which opens the SphS. Anteriorly, the posterior ethmoid air cells are opened. Morphometric measurements evaluating the size of the ALT were done and the PS, NC, EP were explored with the endoscope. RESULTS: The ALT and AMT triangle provides a wide exposure of the PPF, ITF, PPR. In addition, those triangles represent a deep entry point to explore the PS, NC, and EP. CONCLUSION: The ALT and AMT are useful corridors to access to the SphS, MaxS, PS, NC, and EP via a transcranial approach. The use of the endoscope through this corridor widely extend the extradural anterior temporal fossa approach which may be considered as a valuable alternative to the extended endoscopic endonasal approach for selected skull base lesions extending both intracranial and into the PS, NC and EP.

Endoscopic Endonasal Transinfraturbinate Approach With Nasoseptal Window for Removal of the Pterygopalatine Fossa Tumor.

ABSTRACT: Recent advances in endoscopic intranasal technology have allowed for a safe approach to the pterygopalatine fossa lesion. However, we consider that there is still scope of improvement to approach a broader area with better operability and minimal invasiveness. A 51-year-old man underwent endoscopic endonasal surgery due to the recurrence of chordoma at the left pterygopalatine fossa. To access the lower and lateral part of the pterygopalatine fossa, we performed endoscopic endonasal transmaxillary removal via an inferior turbinate incision. During surgery, a wide operative field and good operability could be secured by inserting an endoscope from the right nostril through a window of the nasal septum. Subtotal removal of the tumor was achieved without any complication during the surgery. Endoscopic endonasal transinfraturbinate approach with nasoseptal window was effective in the removal of the pterygopalatine fossa tumor because it is less invasive and provides a good surgical view with better operability.