Clinically relevant morphometric analysis of pterygopalatine fossa and its volumetric relationship with adjacent paranasal sinuses: a CT-based study

OBJECTIVES

This study aimed to perform morphometric measurements of the pterygopalatine fossa (PPF), the transition zone to critical neurovascular structures. The second aim was to investigate the relationship between the volumes of the PPF and the paranasal sinuses and the effect of nasal septum deviation (NSD) types on all these measurements.

METHODS

We performed PPF's morphometry and all volume measurements on the CT images of 260 patients (130 male and 130 female, age range 18-79).

RESULTS

All volumetric measurements and the angle between foramen rotundum (FR) and pterygomaxillary fissure (PMF) were significantly higher in males than females. In contrast, the distance between sphenopalatine foramen (SPF) and PMF was considerably higher in females than in males. The PPF volume, the distance between the pterygoid canal (PC) and maxillary sinus, and the angle between FR and PMF were significantly higher on the right side than on the left. In contrast, the angle between PC and SPF and between greater palatine canal and PPF were considerably higher on the left side than on the right. The angle between PC and SPF decreased markedly with age. Only sphenoidal sinus volume was significantly smaller on the same side as the septal deviation. There was no correlation between PPF volume with maxillary and sphenoid sinus volumes from adjacent paranasal sinuses.

CONCLUSIONS

Volumetric and morphometric data obtained from PPF and paranasal sinuses can aid clinicians in diagnosing and treating patients by guiding them in selecting the right surgical approach or tools, especially in endoscopic procedures.

Endonasal Endoscopic Anatomy of the Orbito-Cavernous-Pterygopalatine Interface: Multilayer Anatomical Description and Landmarks to Define the Limits of the Compartments

BACKGROUND

Despite growing interest in the endoscopic endonasal approach (EEA) to the medial orbital apex (OA), a comprehensive description of the multilayer topology lying at the intersection of the regional compartments is missing.

METHODS

An EEA to the OA, pterygopalatine fossa, and cavernous sinus was performed in 20 specimens. A 360° layer-by-layer dissection was performed taking into consideration relevant anatomical aspects of the interface and documented with 3-dimensional technologies. Endoscopic landmarks were analyzed to provide an outline of the compartments and identify critical structures. Additionally, the consistency of a previously described reference called orbital apex convergence prominence was analyzed and a method to identify its position was introduced.

RESULTS

The orbital apex convergence prominence was an inconsistent finding (15%). However, a craniometric method introduced in this study proved to be reliable to reach the orbital apex convergence point. Additional structures such as the sphenoethmoidal suture and a 3-suture junction (sphenoethmoidal-palatoethmoidal-palatosphenoidal) helped to identify the posterior limit of the OA and define a keyhole to access the compartments of the interface. We defined the bone limits of the "optic risk zone," an area where the optic nerve is more susceptible to damage. Furthermore, an orbital fusion line (periorbita-dura-periosteum) was identified and divided into 4 segments according to adjacent structures: optic, cavernous, pterygopalatine, and infraorbital.

CONCLUSIONS

Understanding cranial landmarks and the folds of the layers covering the orbito-cavernous-pterygopalatine interface can facilitate tailoring an EEA to the medial orbital space and avoid unnecessary exposure of sensitive anatomy in the vicinity.

Soft Air Bullet in the Pterygopalatine Fossa: A Minimally Invasive Endoscopic Approach for Safe Extraction

Ballistic traumas among civilians are usually from low velocity, low calibre weapons such as soft air guns. The facial skeleton is an area of high aesthetic/functional value, and therefore, this is a showcase for technical description of a minimally invasive endoscopic approach for the removal of a bullet from the pterygopalatine fossae.

The application of 3-dimensional magnetic resonance imaging in nasopharyngeal carcinoma with pterygopalatine fossa invasion

OBJECT

The pterygopalatine fossa (PPF) is a covert neurovascular pathway in the skull base and connects with numerous intracranial and extracranial spaces. The aim of this study was to explore the magnetic resonance imaging (MRI) features of PPF invasion in patients with nasopharyngeal carcinoma (NPC).

MATERIAL AND METHODS

The medical records of 88 patients with stage T3 or T4 NPC were retrospectively analyzed. The 3-Dimensional (3D) volumetric images of MRI were reconstructed for the tiny connecting conduits of the invaded PPFs in the NPC patients. The infiltration incidence of conduits and connected further structures were calculated.

RESULTS

Forty-six PPFs from 37 patients were invaded by NPC. The proportions of stage T4 NPC and intracranial extension were higher in patients with PPF invasion than that without PPF invasion (P < 0.05). Each connecting conduit of the PPF had corresponding optimal reconstructed orientation based on 3D volumetric MRI images. The first three most common infiltrated conduits were palatovaginal canal, vidian canal and sphenopalatine foramen, which were adjacent to the nasopharynx. Among the conduits connecting with further structures, the most common infiltrated conduit was pterygomaxillary fissure, followed by foramen rotundum and inferior orbital fissure. Furthermore, The NPC lesions involved stage T4 structures via the conduits from 19.6% of the invaded PPFs.

CONCLUSIONS

The application of high-quality reconstruction images based on 3D sequence of MRI in NPC patients proved to be feasible and beneficial for the manifestation of the invaded PPFs and connecting conduits.

The Varied Presentations of Sinonasal Region Schwannomas: Apropos of Four Cases

Schwannomas of the sinonasal compartment are rare benign neoplasms of peripheral nerve sheath origin and constitute ~ 4% of all head and neck schwannomas. The presentation may simulate a range of benign and intermediate grade pathologies. Management involves surgical excision via open or endoscopic approach. To describe the clinico-epidemiological characteristics and surgical outcomes in sinonasal region schwannoma patients operated at our institute. The study is a descriptive case series of patients with sinonasal region schwannomas treated at our institution. A retrospective search of electronic database of the Department of ENT and Head and Neck Surgeries and Department of Pathology was conducted from January 2013 to January 2019. The various demographic and clinical details of the patients were extracted. A total of four patients operated for sinonasal region schwannoma were identified. The involved sites were nasal dorsum, nasal cavity, pterygopalatine fossa and infratemporal fossa. The mild, non-specific symptoms resulted in patients ignoring their symptoms for a while initially and presenting late. The nasal dorsum lesion was revealed as a surprise during open rhinoplasty for correction of nasal deformity. Complete excision was achieved in all the cases and no recurrence has been noticed during the follow up (varying from 6 months to 6 years) till date. The diverse clinical manifestations and approaches to the treatment of schwannomas in this specific region are discussed. The surgical excision is the standard of care in dealing with these neoplasms. This series highlights the rarity of this pathology in the sinonasal area, diagnostic surprises and the decision making to choose the correct surgical approach for complete excision. Once excised completely, recurrence is not expected.

Glomus Tumor of the Pterygopalatine Fossa: A Rare Case Report

The pterygopalatine fossa (PPF) is a challenging space and pathological processes in this anatomical space are uncommon. This report presents a case of glomus tumor right PPF in a 65 years old female patient who underwent tumor removal by endoscopic transnasal-transmaxillary approach with preoperative selective embolization of the right internal maxillary artery.

CT-Guided Thermocoagulation of the Pterygopalatine Ganglion for Refractory Trigeminal Autonomic Cephalalgia

INTRODUCTION

Trigeminal autonomic cephalalgia (TAC) is a type of one-sided cerebral painful headache, with attacks regularly accompanied by autonomic responses, such as tearing, runny nose, panic, nausea and vomiting on the affected side. Currently, the most common treatment strategies are drugs, nerve grafts and surgery. Clinical understanding of TACs is limited. Here, we report the case of thermocoagulation treatment of the pterygopalatine ganglion in an uncommon TAC under local anesthesia.

CASE PRESENTATION

A rare case of TAC was treated with computed tomography (CT)-guided thermocoagulation within the pterygopalatine ganglion. Pain and autonomic signs were relieved immediately after surgery, with the patent retaining only slight numbness on the left side of the face. This numbness completely resolved at 6 months of follow-up and there was no recurrence.

DISCUSSION

Trigeminal autonomic cephalalgia seriously affects the patient's quality of life, but clinical understanding is limited. In the case reported here, we performed CT-guided thermocoagulation of the pterygopalatine ganglion at 90 °C for 180 s for treatment of a trigeminal autonomic headache. To our knowledge, this is the first report of using thermocoagulation at 90 °C to treat the pterygopalatine ganglion. We found that this strategy results in fewer side effects and is a more cost-effective treatment for such patients than other options.

CONCLUSION

Computed tomography-guided thermocoagulation of the pterygopalatine ganglion at 90 °C for 180 s for treatment of trigeminal autonomic headache is a safe and economical treatment option.

Mucormycosis in COVID-19 pandemic and its neurovascular spread

PURPOSE

Rhinocerebral mucormycosis is a rapidly progressive angioinvasive fungal infection commonly seen in diabetics. In the COVID-19 pandemic we have witnessed a sudden surge in these cases. We aimed to evaluate the disease presentation, patterns of spread, and any association with the COVID-19 virus.

METHODS

This prospective study was conducted on mucormycosis patients operated between March and July 2021. The diagnosis was confirmed either on KOH staining, fungal culture or histopathological examination.

RESULTS

Thirty one cases (21 males, 10 females) with a mean age of 53.3 years were included, of which 9 (29.1%) were COVID positive on presentation, 17 (54.8%) were post-COVID, while 5 (16.1%) had radiological evidence of COVID sequelae. Most common symptoms were cheek numbness (87.1%), headache (83.9%), visual disturbances (77.4%), and palate involvement (58.1%). Blackening of turbinates was uncommon (22.6%). Ethmoid sinus was involved in all patients. Pterygopalatine fossa involvement was present in 77.4%, and was accurately diagnosed on contrast enhanced MRI scan. There were 8 (25.8%) deaths, while the remaining are discharged or under treatment.

CONCLUSION

An increase in the incidence of mucormycosis in the COVID-19 pandemic is probably due to a compromise in host immunity along with a synergistic effect in thrombotic microangiopathy. Spread of infection to the soft tissues of the infratemporal fossa, orbit or palate occur via neurovascular structures rather than by bone erosion. The pterygopalatine fossa is involved in most individuals.

From CT to 3D Printed Models, Serious Gaming, and Virtual Reality: Framework for Educational 3D Visualization of Complex Anatomical Spaces From Within-the Pterygopalatine Fossa

We describe the framework for capturing the internal view of complex anatomical spaces via multiple media and haptic platforms, exemplified by realistic and conceptual representations of the pterygopalatine fossa (PPF). A realistic three-dimensional (3D) mesh of the PPF was developed by segmenting the osseous anatomy on computed tomography (CT) using Materialize InPrint. Subsequently in Autodesk 3D Studio Max, the realistic mesh was enhanced with graphically designed neurovascular anatomy and additionally a conceptual representation of the PPF with its connections and contents was created. An interactive web-compatible Adobe Flash tutorial using ActionScript was developed, allowing users to advance through a series of educational slides that contained interactive rotatable interior camera views and scrollable CT cross-sectional content, incorporating both the realistic and conceptual models. Both models were also 3D printed using polyamide material. In the realistic model, the neurovasculature was colored with water-based acrylic paint. A 3-piece modular design with embedded magnets allows for internal visualization and seamless assembly. A serious gaming environment of the conceptual PPF was also developed using Truevision3D application programming interface, where users can freely move around rooms and hallways that represent various spaces. Lastly, the realistic model was incorporated into a headset-based virtual reality environment, Surgical Theater, allowing visualization and fly-through inside and outside the model. Multiple 3D techniques for visualization of complex 3D anatomical spaces from within were described, with the necessary software and skills detailed. A rough estimate of the time and cost needed to develop these tools as well as multiple supplementary source and end result files are also made available. Educators could utilize multiple advanced delivery methods to incorporate custom digital 3D models of complex anatomical spaces understood from inside.

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.

The endoscopic prelacrimal recess approach to the paramedian middle cranial base: An anatomical study

BACKGROUND

Endoscopic endonasal approach to paramedian cranial base implies sacrifice of the nasal structures.

OBJECTIVE

The present study aimed to illustrate the anatomy and provide critical anatomical landmarks for the endoscopic prelacrimal recess approach (PLRA) to the paramedian middle cranial base.

METHODS

Anatomical dissections were performed in 10 cadaveric specimens.

RESULTS

Successful access to the paramedian middle cranial base was achieved in all dissections via the PLRA with the removal of the pterygoid process. For the dissection of the infratemporal fossa and pterygopalatine fossa, the buccal nerve and infraorbital neurovascular bundle can serve as important anatomic landmarks to identify the detailed structures. In the upper parapharyngeal space, the stylopharyngeal aponeurosis can present as anatomical barriers to protect the parapharyngeal segment of the internal carotid artery (PPICA); while the levator veli palatini muscle can be considered as a landmark to locate the PPICA. For the dissection of the Eustachian tube (ET), the isthmus of the ET and ET sulcus can serve as useful landmarks to identify the posterior genu of the ICA and horizontal segment of the petrous ICA respectively.

CONCLUSION

The PLRA to the paramedian middle cranial base is anatomically feasible and can facilitate preservation of the integrity of nasal structures. The buccal nerve, infraorbital neurovascular bundle, levator veli palatini muscle, stylopharyngeal aponeurosis, the isthmus of the ET, and ET sulcus can serve as critical anatomic landmarks in their respective region and may facilitate the application of this approach.

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).

Angio-anatomical study of the pterygovaginal artery based on cone-beam computed tomography

PURPOSE

To investigate the anatomical characteristics and clinical implications of the pterygovaginal artery (PtVA), a recurrent branch from the distal internal maxillary artery (IMA), which courses through the pterygovaginal canal that connects the pterygopalatine fossa and nasopharynx.

METHODS

Eighty-two patients with 90 sides of cone-beam computed tomography (CBCT) reconstructed from rotational angiography of the external or common carotid artery with a field of view covering the pterygopalatine fossa were retrospectively reviewed. The origin from the IMA, branching type, distribution, and anastomoses was evaluated. The underlying lesions were 36 hypervascular lesions with possible supply from PtVA (17 cavernous sinus arteriovenous fistulas (AVFs), 6 anterior condylar AVFs, and 13 nasopharyngeal, parasellar, or paraclival tumors) and 46 other diseases.

RESULTS

PtVA was identified in 75 sides (83%). It originated from the pterygopalatine segment of the IMA in 45 sides (60%) and from the pterygoid segment in 30 sides (40%). It arose independently (77%), sharing the common trunk with the Vidian artery (15%) or with other branches. It ran posteromedially through the pterygovaginal canal to supply the mucosa over the nasopharyngeal roof, the choanae, and the pharyngeal ostium of the eustachian tube. It anastomosed with the ascending pharyngeal artery (n=37), the accessory meningeal artery (n=7), and the mandibular artery from the petrous internal carotid artery (n=2). It served as a feeder of osseous AVFs and skull base tumors.

CONCLUSION

PtVA was often identified by CBCT even in normal anatomy. Its detailed angio-anatomy could be evaluated in the presence of parasellar or paraclival hypervascular lesions.

Endonasal endoscopic approach to the pterygopalatine and infratemporal fossae

The pterygopalatine fossa and infratemporal fossa are spaces located under the skull base, housing important neurovascular structures. Surgical access to these spaces is challenging because of their deep location and complex anatomy. Their surgical access has been classically carried out through multiple craniofacial approaches until the advent of endoscopic endonasal surgery at the end of the XX^th century. Our goal is to describe the transmaxillary-transsphenoidal-transpterygoid approach to the pterygopalatine and infratemporal fossae through endonasal endoscopic surgery based on anatomo-surgical dissection and an illustrative clinical case. We conclude that after careful radiologic evaluation of the feasibility of this technique, the endonasal endoscopic access to these spaces for tumor resection is efficient with reduced surgical morbidities. The endonasal approach is versatile and can be fashioned according to the nature and extent of the lesion.

[The maxillary sinus via a prelacrimal approach as a gateway to the retromaxillary space and orbital floor]

Endonasal surgery has emerged as the standard procedure for the majority of nasal and paranasal sinus pathologies. However, some pathological changes beyond the maxillary sinus seem to be out of the instrumental range and are addressed by open approaches. The prelacrimal approach to the maxillary sinus published by Zhou and coworkers has stimulated a rapid development of various procedures in this field. In the current work, the possibilities of the prelacrimal approach are illustrated by means of three clinical cases. The prelacrimal approach enables isolated fractures of the orbital floor to be reconstructed without the risk of lower eyelid complications. Meningo- or encephaloceles in the far lateral aspects of the sphenoid sinus are comparatively well reached via endonasal, transantral, and transpterygoid approaches. Until recently, tumors beyond the maxillary sinus were the domain of open surgery, particularly when they extended laterally of the maxillary sinus. The technique of choice was either a Caldwell-Luc or a midfacial degloving approach. Many of these operations can now be performed via the endonasal prelacrimal approach, with lower morbidity and more rapid postoperative healing. The approach described herein is equal if not superior to the traditional approaches in terms of overview and accessibility.

Efficacy of the Endoscopic Triportal Transmaxillary Approach for Treating Lateral Middle Skull Base Tumors: A Technical Note and Retrospective Case Series

BACKGROUND

The endoscopic approach, chiefly via the maxillary sinus, has growing applications for the lateral skull base, and can be classified into the use of "endonasal" or "sublabial" entry. Although the endonasal transmaxillary approach has been well accepted, it has a limitation with respect to the lateral exposure. A possible solution is the use of the sublabial transmaxillary approach via the canine fossa, which assures lateral accessibility. In clinical practice, we have taken advantage of the concomitant use of the endonasal and sublabial transmaxillary approach for selected patients harboring lateral skull base lesions. In addition to binostril pathways, canine fossa trephination was constructed to facilitate this combined approach, termed the endoscopic triportal transmaxillary approach (ETTA).

METHODS

The efficacy of the ETTA was evaluated within a case series. A single-institution retrospective analysis was performed in patients with lateral middle skull base tumors treated via ETTA.

RESULTS

In clinical practice, 4 patients were eligible for the study, including 1 receiving a combined endoscopic and transcranial approach. No major complications occurred in patients included in this series. The ETTA facilitated the dynamic manipulation of instruments, which led to rapid hemostasis and the satisfactory surgical resection of tumors. Furthermore, it reduced intraoperative postural stress experienced by the surgeons who performed the procedures.

CONCLUSIONS

The concomitant use of the trans-canine fossa approach effectively ameliorated significant technical challenges that tend to occur when using a purely endonasal approach. The ETTA can be an attractive option for treating lateral and middle skull base lesions.

Endoscopic Endonasal Resection of Schwannoma of Pterygopalatine Fossa

Trigeminal schwannomas are benign slow-growing tumors originating from the peripheral nerve sheath. They account for 0.1%-0.4% of all intracranial tumors and 1%-8% of all intracranial schwannomas.^1-3 While most of these tumors develop in the trigeminal ganglion within the middle fossa, trigeminal schwannomas can develop anywhere along the course of the trigeminal nerve. As a result, they can be intradural, interdural, and extradural.^4,5 Trigeminal schwannomas from the pterygopalatine fossa (PPF) are extremely rare and very difficult to remove because of limited access to this region and the rich neurovascular contents. Numerous traditional microsurgical approaches to the PPF have been described; however, they are more invasive with increased morbidity.^6,7 Therefore, endoscopic endonasal surgery is a feasible solution. This technique allows good visualization of the region with decreased morbidity and a shorter recovery period. A previously healthy, 40-year-old woman presented with right facial pain for 3 weeks. On neurologic examination, the patient had hypoesthesia in the territory of the maxillary (V2) branch of the right trigeminal nerve. She had no other symptoms on physical examination. Cranial computed tomography and magnetic resonance imaging were performed and showed a high signal density mass in the right PPF that exhibited heterogeneous contrast enhancement. She was initially treated with low-dose carbamazepine; however, the dose could not be further increased because of drowsiness and dizziness. Given the size and location of the mass, an endoscopic endonasal approach was performed, and the tumor was successfully resected (Video 1). The postoperative course was uneventful, and the patient had significant improvement of her symptoms and was discharged with no new neurologic deficits. However, she continued to have hypoesthesia of the V2 segment of the trigeminal nerve.

Extraoral anatomy in CBCT – a literature review. Part 3: Retromaxillary region

In this review about extraoral anatomy as depicted by cone beam computed tomography, the retromaxillary region is discussed. A medium-sized (6 x 6 cm) or large (≥ 8 x 8 cm) field of view of the maxilla will inevitably depict the retromaxillary region that can be considered a «transition» zone between the viscerocranium and the neurocranium. Major structures of the region include the sphenoid bone and the pterygopalatine fossae. The sphenoid bone is a single but complex bone located between the maxilla and the brain. It is composed of a central body, bilateral greater and lesser wings, and pterygoid processes. Important neurovascular structures pass through the sphenoid bone: the optic nerve and the ophthalmic artery via the optic canal, the maxillary nerve via the foramen rotundum, and the pterygoid nerve via the Vidian canal. The central body of the sphenoid bone also contains the highly variable sphenoid sinus that is the most posteriorly located paranasal sinus. The bilateral pterygopalatine fossae behind the maxillary sinuses contain several important neurovascular structures that supply the maxilla and the midface.

Endoscopic endonasal treatment of maxillary nerve (V2) painful neuropathy: cadaveric study with clinical correlation

BACKGROUND

Surgical access to the second (V2, maxillary) and third (V3, mandibular) branches of the trigeminal nerve (V) has been classically through a transoral approach. Increasing expertise with endoscopic anatomy has achieved less invasive, more efficient access to skull base structures. The authors present a surgical technique using an endoscopic endonasal approach for the treatment of painful V2 neuropathy.

METHODS

Endoscopic endonasal dissections using a transmaxillary approach were performed in four formalin-fixed cadaver heads to expose the V2 branch of the trigeminal nerve. Relevant surgical anatomy was evaluated and anatomic parameters for neurectomy were identified.

RESULTS

Endoscopic endonasal transmaxillary approaches completed bilaterally to the pterygopalatine and pterygomaxillary fossae exposed the V2 branch where it emerged from the foramen rotundum. The anatomy defined for the location of neurectomy was determined to be the point where V2 emerged from the foramen rotundum into the pterygopalatine fossa. The technique was then performed in 3 patients with intractable painful V2 neuropathy.

CONCLUSIONS

In our cadaveric study and clinical cases, the endoscopic endonasal approach to the pterygopalatine fossa achieved effective exposure and treatment of isolated V2 painful neuropathy. Important surgical steps to visualize the maxillary nerve and its branches and key landmarks of the pterygopalatine fossa are discussed. This minimally invasive approach appears to be a valid alternative for select patients with painful V2 trigeminal neuropathy.

Morbidities Associated with the Endoscopic Transnasal Transpterygoid Approach: Focusing on Postoperative Sequelae

OBJECTIVE

Although the endoscopic transpterygoid approach has been popularized, there are no studies about anatomy-specific morbidities of this approach. The objective of this study is to investigate the surgical morbidities associated with the endoscopic transpterygoid approach for resection of anatomic structures.

METHODS

A retrospective analysis was carried out of prospectively collected data of patients who underwent the endoscopic transpterygoid approach for skull base tumor by a single ear nose and throat surgeon in a tertiary-care center from November 2013 to January 2019. Postoperative patient symptom prevalence associated with surgical findings and SNOT-22 (Sino-Nasal Outcome Test-22) score were included in the analysis.

RESULTS

Thirty-seven consecutive patients were enrolled. The mean follow-up period was 12.4 months (range, 1-39 months). Twenty-six (70.3%) vidian nerves were sacrificed, but only 38.5% of those patients (10/26) reported mild dry eye symptoms. Fourteen nasolacrimal ducts (37.8%) were resected, with only 1 patient (7.1%) who had undergone previous radiation therapy reporting transient epiphora. SNOT-22 scores before and after surgery did not present statistical difference in inferior turbinate sacrifice group and preservation group.

CONCLUSIONS

Sacrifice of sinonasal structures such as the inferior turbinate or vidian nerve is sometimes inevitable for safe tumor resection with the endoscopic transpterygoid approach. Subjective symptoms were not apparent in most patients, despite the structural sacrifice.

Skull Base Mucormycosis in an Immunocompetent Patient: A Case Report and Literature Review

To demonstrate the affection of skull base by mucormycosis in an immunocompetent individual. Mucormycosis is an opportunistic infection principally seen in immunocompromised individuals, but recently being increasingly recognized in otherwise healthy individuals. Skull base involvement secondary to otogenic nidus, mimicking otitis media was rarely reported. A 34 year-old male, an otherwise healthy patient presented with facial nerve palsy followed by trismus, neck swelling and neck stiffness. Radical mastoidectomy with tympanoplasty and Facial nerve decompression along with Endoscopic guided debridement of sinuses and pterygopalatine fossa followed by medical treatment for 14 weeks. Facial nerve functioning, dry ear canal and relief from other symptoms. Surgical debridement and post op Anti fungal treatment improved the facial nerve function to House brackmann grade-II and also provided relief from trismus and stiffness and improved the overall general condition of the patient. Mucor is a saprophytic organism, which can cause extensive progression, regardless of the immune status. To the best of our knowledge, this is one of the very few rare cases that have been reported in the context of skull base mucormycosis in immunocompetent individuals. Surgical debridement followed by anti fungal therapy continues to remain the mainstay of treatment.

[Extirpation of primary malignancies in the pterygopalatine and infratemporal fossa via modified maxillary swing approach]

Five patients with primary malignancies in the pterygopalatine fossa (PPF) and infra temporal fossa (ITF) were enrolled in this retrospective study between January 2012 and January 2018. After malignancies proven by biopsy and evaluation with CT and MRI scan, all patients received modified maxillary swing (MMS) approach for extirpation of malignant tumors in the PPF and ITF under general anesthesia. En bloc resection with wide surgical margins was successfully performed in all cases. Negative margins were observed in 4 cases and positive margins were found in one patient with adenoid cystic carcinoma who received postoperative radiotherapy. The most common complication was facial numbness. During the follow-up period (range 12 to 57 months), one patient suffered from recurrence while others did not. The advantages of MMS include wide surgical field, full exposure and easy manipulation. The MMS approach is expected to become an standard method for monobloc resection of malignancies in the PPF and ITF.

Cone-beam computed tomography evaluation of the pterygomaxillary fissure and pterygopalatine fossa using 3D rendering programs

PURPOSE

The aim of this study was to investigate the detailed anatomy of the pterygomaxillary fissure (PMF) and pterygopalatine fossa (PPF) and variations therein using three-dimensional (3D) cone-beam computed tomography (CBCT) software.

METHODS

This study was based on a retrospective evaluation of CBCT scans. A total of 825 CBCT images of patients (448 females, 377 males) who met the inclusion criteria were analyzed. PMF shapes were classified, and morphometric measurements (PMF area and PPF volume) were performed according to age, right/left side, and gender using 3D rendering programs. Maxillary and sphenoid sinus pathologies were also classified to reveal possible correlations between morphometric measurements. Analysis of variance was used for comparisons. Multiple comparisons were assessed using the Bonferroni test. Pearson's test was used to assess correlations between parameters. A p value < 0.05 was considered to indicate statistical significance.

RESULTS

Six types of PMF shapes were defined. There were no significant differences in types according to gender, age or sinus pathology. Males had a significantly larger PMF area than females (p < 0.001). Left/right comparison of the PMF area revealed that the mean PMF coronal, axial, and sagittal area dimensions were significantly higher on the right side in all patients. Our results also indicated that the PMF area and PPF volume increased significantly after 40 years of age.

CONCLUSION

Various PMF shapes were defined and classified. PMF and PPF dimensions increased with age. Knowledge of these anatomical variations will allow surgeons to avoid damage to the neurovascular structures passing through the area.

Diagnostic usefulness of panoramic imaging of the pterygopalatine fossa: case of a schwannoma causing pterygopalatine fossa expansion

The pterygopalatine fossa is a small area between the posterior wall of the maxillary sinus and the anterior surface of the pterygoid process of the sphenoid bone. The pterygopalatine fossa can be seen clearly on panoramic imaging. We present the case of a 57-year-old man who exhibited right pterygopalatine fossa expansion on panoramic imaging. Computed tomography (CT), magnetic resonance imaging (MRI), and panoramic imaging all showed a tumor at the right pterygopalatine fossa in this patient. CT indicated that the tumor replaced right retromaxillary fat and displaced the posterior wall of the maxillary sinus. On MRI, the tumor showed intermediate signal intensity at the paranasal area on T1-weighted images, and variable intermediate and high signal intensities on fat-suppressed T2-weighted images. It was eventually diagnosed as a schwannoma. Thus, panoramic imaging can be used for disease screening at the posterior border of the maxilla. Our conclusion is based on this report of a patient with a schwannoma at the posterior wall of the maxillary sinus, which panoramic imaging revealed to have pterygopalatine fossa expansion.

Endoscopic endonasal approach to the vidian nerve and its relation to the surrounding structures: an anatomic cadaver study

PURPOSE

The aim of this study was to investigate the neurovascular structures and their relevant anatomy with the endonasal endoscopic transpterygoid approach on fresh human cadavers. In addition, the relationship between the vidian nerve, ICA and surrounding structures were investigated METHODS: This study was carried out at an otolaryngology department of a tertiary medical center between June 2014 and June 2015. Ten fresh human cadavers were included in this study. Pterygopalatine fossa was explored via an endoscopic endonasal transpterygoid approach. Same surgical dissection procedures were performed on all cadavers: maxillary antrostomy, anterior and posterior ethmoidectomy, sphenoidotomy, transpterygoid pterygopalatine fossa and vidian canal dissection.

RESULTS

Mean distance between the anterior nasal spine and ethmoidal crest was 60.35 ± 1.31 mm (range 59-64 mm). Mean distance between the sphenopalatine foramen and superior border of choana was 18.30 ± 1.38 mm (range 17-22 mm). Mean distance between the vidian canal and sphenopalatine foramen was 6.30 ± 0.47 mm (range 5.5-7 mm). Mean distance between the vidian canal and anterior nasal spine was 64.6 ± 1.71 mm (range 62-67 mm). Foramen rotundum was located superior lateral to the vidian canal in all specimens. Mean distance between foramen rotundum and vidian canal was 9.45 ± 0.60 mm (range 8.5-10.5 mm). Course of the greater palatine nerve was always medial to the descending palatine artery. The mean length of the vidian nerve from the petrous ICA to the point the nerve exits the vidian canal (vidian canal length) was 17.90 ± 1.59 mm (range 16-20 mm).

CONCLUSIONS

The distances between the vidian canal and surrounding neurovascular structures would help the skull base surgeon in this narrow and complex area.

Impact of age on the anatomy of the pediatric pterygopalatine fossa and its relationship to the suprazygomatic maxillary nerve block

OBJECTIVES

The suprazygomatic maxillary nerve block is associated with improved post-operative pain management after select craniofacial surgical procedures. This study's objective is to better define the impact of pediatric facial skeletal growth on techniques for accessing the pterygopalatine fossa (PPF).

METHODS

Pediatric patients with prior thin-slice maxillofacial computed tomography imaging were identified in an institutional radiology database. Aquarius image-processing software (Ver. 4.4.11, TeraRecon, Inc., Foster City, CA) was used to measure from the suprazygomatic skin to the greater wing of the sphenoid where the needle is then re-oriented in an anterior and inferior trajectory allowing it to advance into the PPF.

RESULTS

A total of 90 patients ranging from 0 to ≤18 years of age were included in the study. The mean distance from the suprazygomatic skin to the foramen rotundum in patients 0 to ≤12 months of age and >13 to ≤18 years of age was 38.6 (SD ± 4.7) and 47.1 (SD ± 3.2) mm, respectively (p < .0001). The statistical analysis demonstrated a positive correlation between age in years and all of the measured distances (p = .0001). With respect to the plane of the needle entry site, the anterior and inferior angles required for passage into the PPF in the 0 to ≤12 months age group were 11 (SD ± 2.1) and 9.0 (SD ± 2.5) degrees, respectively, compared to those in the >13 to ≤18 years of age group at 12.4 (SD ± 1.9) and 12.1 (SD ± 3.2) degrees, respectively. These data reveal that patients in the oldest compared to the youngest pediatric age groups require significantly greater needle insertion, yet the angles of needle re-orientation are clinically similar between these two pediatric age groups varying by up to only 3°.

CONCLUSION

As expected, the distance from the skin to the foramen rotundum increases significantly with age; however, the angles of re-orientation with respect to the original needle entry site demonstrated up to only 3° of variability between the youngest and oldest age groups evaluated in this pediatric cohort.

Endoscopic Endonasal Craniofacial Surgery for Recurrent Skull Base Meningiomas Involving the Pterygopalatine Fossa, the Infratemporal Fossa, the Orbit, and the Paranasal Sinus

OBJECTIVE

Skull base meningiomas carry a nonnegligible risk of recurrence. In particular, those arising from the sphenoid wings or middle cranial fossa penetrate into extracranial regions, uncommonly showing massive expansion into the craniofacial regions on recurrence. The role of endoscopic endonasal surgery for those intractable lesions remains unclear.

METHODS

We performed endoscopic endonasal craniofacial surgery for 8 recurrent meningiomas invading into the pterygopalatine fossa, infratemporal fossa, nasopharynx, paranasal sinus, or orbit, comprising 2 meningothelial and 1 fibrous meningiomas (World Health Organization [WHO] grade I), 3 atypical and 1 clear cell meningiomas (grade II), and 1 anaplastic meningioma (grade III). All were large (15-80 cm³; median, 45 cm³) and highly vascularized.

RESULTS

All 8 tumors were sufficiently resected. Gross total resection of the craniofacial part of the lesions was achieved in 5 patients (62.5%). In 3 patients with WHO grade I meningiomas and 1 with grade II, tumors were successfully controlled as of the last follow-up. In 4 patients with WHO grade II or III meningiomas, craniofacial lesions were controlled, whereas original intracranial lesions were poorly controlled and became critical.

CONCLUSIONS

We consider the endoscopic endonasal approach as an acceptable, less-invasive alternative for recurrent craniofacial meningioma. Although all these cases were relatively large and highly vascularized, preoperative endovascular embolization of the feeding arteries contributes to significantly reducing vascularity of the tumors, and local control of the craniofacial lesions was successfully achieved in all cases. Endoscopic endonasal craniofacial surgery enabled sufficient mass reduction without disfiguring facial incisions.

Is Pterygopalatine Fossa Injection with Adrenaline an Effective Technique for Better Surgical Field in Fess?

Functional endoscopic sinus surgery (FESS) is one of most common surgeries in otorhinolaryngology practice. It is done in the narrow confines of the nasal cavity. Bleeding into the surgical field is a major problem faced by endoscopic surgeons. To assess the effectiveness of pterygopalatine fossa infiltration with lignocaine and adrenaline in controlling surgical field bleeding during endoscopic sinus surgery. A randomized blinded study was done among 68 patients who underwent FESS. Infiltration with 2% lignocaine with 1:80,000 adrenaline was given only on one side and the surgeon was blinded as to which side was infiltrated and he was asked to assess the surgical field using a standard scale. There was statistical significant improvement in surgical field on the infiltrated side (p = 0.001) with almost 25-30% improvement in surgical field on the infiltrated side. The surgical field bleeding also varied with the blood pressure with a positive correlation. There were no complications associated with the procedure. Pterygopalatine fossa infiltration with lignocaine and adrenaline is an effective technique in reducing surgical field bleeding during FESS. It can be combined with nasal decongestion or hypotensive anaesthesia for an optimum surgical field.

3D printing the pterygopalatine fossa: a negative space model of a complex structure

PURPOSE

The pterygopalatine fossa is one of the most complex anatomical regions to understand. It is poorly visualized in cadaveric dissection and most textbooks rely on schematic depictions. We describe our approach to creating a low-cost, 3D model of the pterygopalatine fossa, including its associated canals and foramina, using an affordable "desktop" 3D printer.

METHODS

We used open source software to create a volume render of the pterygopalatine fossa from axial slices of a head computerised tomography scan. These data were then exported to a 3D printer to produce an anatomically accurate model.

RESULTS

The resulting 'negative space' model of the pterygopalatine fossa provides a useful and innovative aid for understanding the complex anatomical relationships of the pterygopalatine fossa.

CONCLUSION

This model was designed primarily for medical students; however, it will also be of interest to postgraduates in ENT, ophthalmology, neurosurgery, and radiology. The technical process described may be replicated by other departments wishing to develop their own anatomical models whilst incurring minimal costs.

Sphenopalatine ganglion block for relieving postdural puncture headache: technique and mechanism of action of block with a narrative review of efficacy

The sphenopalatine ganglion (SPG) is a parasympathetic ganglion, located in the pterygopalatine fossa. The SPG block has been used for a long time for treating headaches of varying etiologies. For anesthesiologists, treating postdural puncture headaches (PDPH) has always been challenging. The epidural block patch (EBP) was the only option until researchers explored the role of the SPG block as a relatively simple and effective way to treat PDPH. Also, since the existing evidence proving the efficacy of the SPG block in PDPH is scarce, the block cannot be offered to all patients. EBP can be still considered if an SPG block is not able to alleviate pain due to PDPH.

Anatomical landmarks for maxillary nerve block in the pterygopalatine fossa: A radiological study

INTRODUCTION

The aim of this study was to describe the anatomical landmarks for maxillary nerve block in the pterygopalatine fossa. The risk of injury to the skull base and maxillary artery was assessed.

METHODS

This retrospective study was based on the analysis of 61 consecutive computed tomography angiographies obtained from patients suffering from different pathologies. Anatomical relationships between optic canal (OC), foramen rotundum (FR), inferior orbital fissure (IOF) and puncture point (PP) were assessed. A "maxillary section" was virtually carried out on the CTs, following a plane passing through PP, IOF and FR in order to mimic the anaesthesia needle route.

RESULTS

No gender difference was observed except for the PP-OC distance that was longer in men. The mean PP-IOF distance was of 31.9 (± 0.7mm). PP-OC (43.9±0.5) and PP-FR (44.2±0.7) distances increased significantly with the patients height (PP-FR=17.25+0.16×height (cm); PP-OC=20.54+0.13×height (cm)). The route to the skull base was curved, with an angle of 168±1.6° at the FR level. The angle to reach the OC was greater than 7°.

DISCUSSION

With a 35-mm needle length, the probability to reach the IOF was high (79%), while the risk to injure the skull base (2%) and the optical nerve (0%) was low. Artery injuries were only found in 13% of cases. Therefore, a 35-mm needle length allows for the best efficacy/risk ratio in maxillary nerve block.

Endoscopic Resection of Pterygopalatine Fossa and Infratemporal Fossa Malignancies

The endoscopic resection of pterygopalatine and infratemporal fossa malignancies allows excellent visualization and manipulation of tissues in an anatomically complex area compared with open approaches. With less approach morbidity, endoscopic endonasal surgery allows an easier recovery and earlier transition to adjuvant radiotherapy. The endoscopic approach is minimal access but rarely minimally invasive. Surgeons should not hesitate to gain wide surgical exposure of the pterygopalatine, infratemporal fossa, and petrocavernous carotid artery to ensure comfortable maneuverability and easy visualization of the tumor and its normal tissue margins. This method maximizes the chances of complete resection and effective postoperative surveillance.

Unusual foramen in the middle cranial fossae of adult black South African skull specimens

Variations of the skull base foramina are quite common and often cause surgical confusion during surgical intervention of the region. The unusual foramen was observed in five (0.98%) adult skulls of black South Africans obtained from the Raymond A Dart collection of human specimens housed in the School of Anatomical Sciences at the University of the Witwatersrand. Three of the five specimens were females while the remaining two were males. In four of the five skulls, the unusual foramen was located anterolateral to the foramen rotundum both on the left and right sides. In the fifth specimen, the foramen was located posterolateral to the foramen rotundum on the left half of the middle cranial fossa. On radiographs, two specimens with unusual foramen on the right showed that the foramen opened into a canal directed inferomedially towards the pterygopalatine fossa. In the remaining three specimens, the canals were blind and shallow. This information is vital during interpretation of CT scans at the base of the skull, as any less well-known foramen may be mistaken for abnormalities leading to surgical complications.

Transantral endoscopic approach for the treatment of lesions affecting the maxillary nerve

BACKGROUND

Surgical approaches to skull base lesions that affect the maxillary nerve are complex, due to deep location and presence of relevant neurovascular structures surrounding this area.

METHOD

We propose the transantral endoscopic approach (TEA) for the treatment of lesions affecting the maxillary nerve or its vicinity. More specifically, the ones that are located anterior to the foramen rotundum.

CONCLUSIONS

This technique represents a minimally invasive treatment option for these kind of cranial base lesions. It offers optimal visualisation similar to the endonasal approach, whereas less dissection is required.

The pterygopalatine fossa: imaging anatomy, communications, and pathology revisited

Abstract

The pterygopalatine fossa (PPF) is a small, clinically inaccessible, fat-filled space located in the deep face that serves as a major neurovascular crossroad between the oral cavity, nasal cavity, nasopharynx, orbit, masticator space, and the middle cranial fossa. Due to its inherent complex location and connections, it can potentially act as a natural conduit for the spread of inflammatory and neoplastic diseases across the various deep spaces in the head and neck. This review aims to acquaint the reader with the imaging anatomy of the PPF, its important communications, and to identify some major pathological conditions that can involve the PPF, especially in conditions where its involvement can have serious diagnostic and therapeutic implications, such as in perineural tumour spread.

Teaching points

• The PPF is a small neurovascular junction in the deep face with important to-and-fro connections.

• Awareness of anatomy of the PPF and its communications helps to simplify imaging of its pathology.

• Perineural tumour spread is clinically the most important pathology in this region.

The posterior groove as a landmark for location of the palatovaginal canal in axial computed tomography

PURPOSE

To investigate use of posterior groove of palatovaginal (PV) canal as an anatomic landmark in determining the location of PV canal in axial computed tomography (CT) images of pterygopalatine fossa (PPF).

METHODS

A total of 20 skull specimens were examined in this analysis. Each skull was scanned by CT with and without a probe inserted through PV canal to measure the anatomic structures. CT images of 70 patients were used for comparing the rate of correct location of PV canal between the conventional method (using the vidian canal as a landmark) and the method of using the posterior groove as a landmark. Two skulls were dissected using endoscopy to further reveal the advantage of the posterior groove as a landmark.

RESULTS

In all 20 skull specimens, the groove showed the morphology of a narrow groove and elliptical fossa in 24 and 16 sides, respectively. In CT images, the angle from PV canal and the posterior groove to the hard palate was 53.14° ± 5.48° and 20.93° ± 6.28°, respectively, which was significantly different (P ≤ 0.05). The rate of correct location of PV canal was statistically significantly higher with the method of posterior groove as a landmark than the conventional method (70.7 vs 49.3 %, P < 0.05). The endoscopic anatomy of the posterior groove and its use in locating the PV canal were described.

CONCLUSION

The posterior groove can be used as an anatomic landmark in correctly locating PV canal in the axial CT image of the PPF.

Anatomic variation in the pterygopalatine angle of the maxillary sinus and the maxillary bulla

Bulges of the most posterior ethmoid air cells into the maxillary sinus were termed maxillary bullæ by Onodi. With few exceptions, they have since been ignored by anatomists through time. Likewise, Sieur cells-the spheno-ethmoido-maxillary air cells-are uncommonly found in anatomical texts. We therefore aimed to perform a retrospective cone beam computed tomography study on 50 patients to document the possibilities of anatomic variation in the situs of the orbital process of palatine bone-a variation related anatomically with the pterygopalatine fossa (PPF) and the respective angle of the maxillary sinus. Commonly occurring pneumatizations in this situs were the Sieur cell (58 %/64 % right/left side), and the maxillary recess of the sphenoidal sinus (20 %/22 % right/left side). Alone or in combination, these determined, but not exclusively, the maxillary bullæ. Uncommon pneumatizations in the anterior wall of the PPF were also found, such as a sphenoidal recess of the maxillary sinus, and lateral (maxillary, or pterygopalatine) recesses of the middle and superior, respectively, nasal meatuses. In two different cases, non-Haller, and non-Sieur posterior ethmoid air cells were found extruded posterior to the maxillary sinus. Significant statistical association indicated bilateral symmetry of Sieur's cell and of the maxillary recess of the sphenoidal sinus. It is important to identify such variant pneumatizations on a case-by-case basis in different surgical procedures and endoscopic corridors.

Value of intra- and post-operative cone beam computed tomography (CBCT) for positioning control of a sphenopalatine ganglion neurostimulator in patients with chronic cluster headache

INTRODUCTION

The objective of this study was to determine whether postoperative control of the neurostimulator placement within the pterygopalatine fossa (PPF) by means of 3-dimensional (3D) cone beam computed tomography (CBCT) was of therapeutic relevance compared to intraoperative CBCT imaging alone.

MATERIAL AND METHODS

Immediately after implantation of the sphenopalatine ganglion (SPG) neurostimulator, intraoperative CBCT datasets were generated in order to visualize the position of the probe within the PPF. Postoperatively, all patients received a CBCT for comparison with intraoperatively acquired radiographs.

RESULTS

Twenty-four patients with cluster headache (CH) received an SPG neurostimulator. In 4 patients, postoperative CBCT images detected misplacement not found in intraoperative CBCT. In 3 cases, electrode tips were misplaced into the maxillary sinus and in 1 case into the apex of the PPF superior to the suspected location of the SPG. Immediate revision with successful repositioning within 3 days was done in 2 patients and a deferred reimplantation in 1 patient within 6 months. One patient declined revision.

CONCLUSION

We were able to demonstrate the clinical value of postoperative dental CBCT imaging with a wide region of interest (ROI) due to a superior image quality compared with that achieved with intraoperative medical CBCT. Although intraoperative 3D CBCT imaging of electrode placement is helpful in the acute surgical setting, resolution is, at present, too low to safely exclude misplacement, especially in the maxillary sinus. High-resolution postoperative dental CBCT allows rapid detection and revision of electrode misplacement, thereby avoiding readmission and recurrent tissue trauma.

Treatment of a subtype of trigeminal neuralgia with descending palatine neurotomy in the pterygopalatine fossa via the greater palatine foramen-pterygopalatine canal approach

PURPOSE

To discuss an effective surgical treatment of a subtype of trigeminal neuralgia with descending palatine neuralgia of the maxillary division.

METHOD

Nine patients, who suffered from trigeminal neuralgia with descending palatine neuralgia of the maxillary division, received neurotomy and avulsion of the descending palatine nerve in the pterygopalatine fossa via the greater palatine foramen-pterygopalatine canal approach. Seven of the patients had a recurrence of descending palatine neuralgia after they received treatment of maxillary neuralgia with neurotomy and avulsion of the infraorbital nerve; two patients were diagnosed with descending palatine neuralgia of the maxillary division in our department. Postoperative follow-up was conducted.

RESULTS

Pain in the palate disappeared; all patients felt numb and paresthetic in the area innervated by the trigeminal nerve, with no pain. During the 3-36 months of follow-up, no recurrence occurred.

CONCLUSIONS

Descending palatine neurotomy in the pterygopalatine fossa via the greater palatine foramen-pterygopalatine canal approach is a simple, safe and effective way to treat a subtype of trigeminal neuralgia--descending palatine neuralgia.

Endoscopic endonasal approach for the treatment of schwannomas of the pterygopalatine fossa: case report and review of the literature

INTRODUCTION

Pterygopalatine fossa (PPF) schwannomas are rare lesions most often arising from branches of the trigeminal nerve. Symptomatic lesions have been traditionally treated by conventional external approaches. However, the development of an expanded endonasal approach (EEA) enables skull base surgeons to reach these deeply seated lesions via a different route with its own advantages and drawbacks.

METHODS

Case report and review of the literature.

CASE DESCRIPTION

A 41-year-old woman presented with a 6-year history of right facial pain and numbness. Her symptoms had increased progressively over a year, and she recently had developed right-sided otalgia. MRI revealed a right PPF mass, hypointense on T1 and T2 sequences with homogeneous enhancement following the use of gadolinium. A biopsy, attempted at another institution, was considered non-diagnostic. We totally removed the lesion through an endoscopic endonasal transmaxillary approach. Final pathology confirmed the diagnosis of schwannoma. Post-operatively, the patient noted a significant improvement of her facial pain (V2 territory).

CONCLUSION

The endonasal endoscopic transmaxillary approach provides adequate access to the PPF, thus enabling safe tumor removal with less morbidity than conventional routes.

[A pediatric case of hydatid cyst in the infratemporal fossa]

INTRODUCTION

Hydatid cyst or disease is an anthropozoonosis due to the development of the larval form of the taenia Echinococcus granulosus in humans. It is endemic in Morocco. The location of a hydatid cyst in the infratemporal fossa (ITF) is extremely rare. The authors report a pediatric case.

OBSERVATION

An 11 year old child was admitted to hospital with a history of left latero-facial swelling gradually increasing in volume for 2 months, CT scan of the face revealed a cystic formation of 7 cm diameter sitting at the left ITF, hydatid serology was negative. A transzygomatic approach allowed the excision of the cyst. The histopathological examination of the resected specimen confirmed the diagnosis of hydatid cyst.

DISCUSSION

The location at the infratemporal fossa of an expansive process such as hydatid cyst in children may have a particular impact on adjacent structures and a more meaningful clinical expression. The rate of growth of hydatid cysts is highly variable and ranges from 1 to 5 cm a year. Hydatid serology is often negative. CT examination is the gold-standard radiological examination. Surgical removal of the hydatid cyst is the most effective treatment. The transzygomatic approach allowed a sufficient access to the cyst and a good quality of excision.

Endoscopic approach to the trigeminal nerve: an anatomic study

OBJECTIVE

To describe an endoscopic perspective of the surgical anatomy of the trigeminal nerve.

METHODS

Nine adult cadaveric heads were dissected endoscopically.

RESULTS

Opening the pterygopalatine fossa is important because many key anatomical structures (V2, pterygopalatine ganglion, vidian nerve) can be identified and traced to other areas of the trigeminal nerve. From the pterygopalatine ganglion, the maxillary nerve and vidian nerve can be identified, and they can be traced to the gasserian ganglion and internal carotid artery. An anteromedial maxillectomy increases the angle of approach from the contralateral nares due to an increase in diameter of the piriform aperture, and provides excellent access to the mandibular nerve, the petrous carotid, and the cochlea.

CONCLUSIONS

Identification of key anatomical structures in the pterygopalatine fossa can be used to identify other areas of the trigeminal nerve, and an anteromedial maxillectomy is necessary to expose the ipsilateral mandibular nerve and contralateral cranial level of the trigeminal nerve.

Efficacy and feasibility of frontozygomatic angle approach for extra oral maxillary nerve block in oral surgery: a descriptive clinical trial

BACKGROUND

Pain control is an integral part of minor oral surgery and maxillary/mandibular nerve blocks have proved promising in achieving the same. Although intra oral techniques of maxillary nerve block are common and are widely used, there are certain inherent disadvantages and potential complications. Less commonly described in the literature, the extra oral techniques have a wide spectrum of indications as well as can be more advantageous than the intra oral approach. This prospective clinical trial is an attempt to evaluate the feasibility and the efficacy of the extra oral frontozygomatic approach to the foramen rotundum to block the maxillary nerve.

MATERIALS AND METHODS

Sample size was 100 patients and the inclusion criteria were patients of ASA I or II category who needed extraction of a minimum of 4 maxillary teeth in the same quadrant in a single sitting while exclusion criteria were patients with a history of allergy to local anesthesia, medically compromised patients in whom dental extraction was contraindicated. Mean age was 71.9 years and 56 patients were males while 44 were females. Only a single quadrant (first or second) was chosen as the operative site in each patient and local anaesthesia was secured using a 21 gauge 89 mm long spinal needle with frontozygomatic angle approach and the parameters used were pain experienced during the injection, onset of subjective symptoms, time required for the peak effect (objective symptoms), pain during extraction and the duration of anesthesia. All the parameters were expressed as mean values with standard deviations.

RESULTS

A successful anesthesia was secured in first attempt in 98 patients while in 2 patients, the procedure had to be repeated owing to the difficulty in reaching the target site. A majority of the patients i.e., 71 % scored 0-2 (no pain) on visual analogue scale (VAS) while only 2 patients experienced a moderate degree of pain. Subjective symptoms were reported in 27.24 s (mean value) and 12.93 s (mean value) in the palate and the infraorbital fossa respectively. Peak effect of anesthesia was noted in 66.7, 37.38 and 31.71 s (all values expressed as mean) in palate, infraorbital fossa and posterior superior alveolar areas respectively.

CONCLUSION

Although with only dental extraction as the procedure of choice, the present study has favoured the frontozygomatic angle approach for the maxillary nerve block as simple, safe, efficacious and associated with minimum and clinically mild complications.

Pterygopalatine fossa segment neurectomy of maxillary nerve through maxillary sinus route in treating trigeminal neuralgia

PURPOSE

To explore an effective surgical treatment for pain in the distribution area of the maxillary branch of trigeminal nerve (TN).

MATERIALS AND METHODS

Twenty-six patients with pain in the distribution of the maxillary branch of TN were followed up after they had undergone pterygopalatine fossa segment neurectomy of maxillary nerve through maxillary sinus route.

RESULTS

In all cases, the pain initially resolved after operation, with anaesthesia or paraesthesia in the operated side of the maxillary nerve-distributed area. After a mean follow-up period of 24 (range 3-36) months, 19 (73.08%) of the 26 patients had an excellent response, 5 (19.23%) had a good response, 2 (7.69%) had a fair response, and none (0%) had a poor response. One patient had a recurrence with palatal pain 3 months after the operation.

CONCLUSIONS

The maxillary sinus route can provide a clear vision for sectioning of the maxillary nerve. This new surgical technique has proven to be safe and effective. It provides another option for the weak elderly who are intolerant of craniotomy or patients who have contraindications for craniotomy when radiofrequency thermocoagulation (RFT) and percutaneous glycerol neurolysis (PGR) treatment is not possible.

Combined cranionasal surgery for spheno-orbital meningiomas invading the paranasal sinuses, pterygopalatine, and infratemporal fossa

OBJECTIVE

To evaluate the efficacy of combining an endonasal endoscopic skull-base approach and repair with a transcranial orbitozygomatic approach for spheno-orbital meningiomas (SOMs).

METHODS

Three patients with recurrent SOMs underwent combined orbitozygomatic and endonasal endoscopic surgery. In 2 patients both procedures were done in 1 operation and in 1 patient the endonasal surgery was done 2.5 months after the craniotomy. Extent of resection, complications, morbidity, and mortality were evaluated.

RESULTS

Gross total resection was achieved in 1 patient and near total resection in the other 2 patients with tumor left in the cavernous sinus and parapharyngeal space. Two patients suffered cranial neuropathy from the transcranial surgery and the other developed a pseudomeningocele. There were no complications from the endonasal surgery. Patients having combined single setting cranionasal surgery were discharged on day 6 and 8, whereas the patient having only the endonasal component on a later date was discharged on day 2.

CONCLUSIONS

A combined cranionasal approach involving transcranial orbitozygomatic and endonasal endoscopic approaches is an effective 2-stage surgery for resecting SOMs invading into the sinuses and paranasal compartments. The ability to perform a multilayer closure involving a vascularized nasoseptal flap additionally decreases the risk of postoperative cerebrospinal fluid leak.

Facial translocation approach to infratemporal fossa and cranial base in extensive angiofibroma: A review of 7 cases

Angiofibroma extending to infratemporal fossa, orbit and middle cranial fossa is a difficult problem for a surgeon to tackle. Traditional extracranial excision with radiotherapy for the intracranial extension was practiced for a long time with variable results. Different approaches to remove such a tumour are described but most of them are not free from resultant morbidity in the form of facial asymmetry and incomplete tumour removal. Facial translocation approach facilitates complete tumour removal without cutting through the tumour thereby reducing per-operative blood loss. It also avoids facial asymmetry as the zygomatico-orbito-maxillary bony complex is replaced after the tumour removal. We present a review of seven cases with the results. The surgical steps, advantages, disadvantages and the complications are discussed.