The jugular fossa is a highly complex anatomical area closely related to critical neurovascular structures. To achieve optimal exposure while minimizing its morbidity is the goal of all skull base surgeries. To obtain proximal and distal exposure of the major vessels is an important basic principle in the management of all vascular tumors [5–7]. This dictum above all should determine the degree of exposure required in the management of TJPs, due to their invariable involvement of the ICA.

Two critical points to consider when obtaining adequate surgical exposure are whether the facial nerve (FN) needs mobilization and whether the middle ear can be preserved. These issues form the core argument in the treatment of jugular fossa pathology. It is not the intracranial extension that is the primary consideration that has to be taken into account while selecting an approach, but the degree and nature of ICA involvement. Most of the documented approaches that avoid FN rerouting limit the degree of exposure of the intrapetrous ICA and certainly limit any ability to safely remove bone around this vessel, which is usually required in the management of C2–C4 TJP. For alternate pathologies of the jugular fossa, more “conservative” approaches in relation to both the FN and middle ear structures can often be utilized.

This ITFA type A has been the mainstay of surgery for TJPs ever since it was described by Fisch and Pillsbury in 1979 [8]. The ITFA type A is designed to allow access to the jugular foramen area, the infralabyrinthine and apical compartments of the petrous bone, the vertical segment of the internal carotid artery, and the upper jugulocarotid space (Fig. 8.1a). The approach is designed primarily for extensive extradural lesions involving these areas. The key point in this approach is the anterior transposition of the FN to provide optimal control of the targeted areas (Fig. 8.1b). The other structures that prevent lateral access to these areas are shown in Fig. 8.1c. Besides the FN they include the tympanic bone, the digastric muscle, and the styloid process. These structures are removed to allow an unhindered lateral access. The morbidity associated with the classic ITFA type A includes conductive hearing loss, temporary or permanent FN dysfunction due to permanent anterior rerouting of the nerve, and temporary masticatory difficulties.

In the recent past, many authors have favored the technique of retaining the FN in situ without rerouting it in the ITFA type A and/or attempt to conserve the external auditory canal in the resection of jugular fossa tumors [9–16]. Unfortunately, however, these reports often do not clearly differentiate between vascular and nonvascular tumors nor do they discuss the stage of the paragangliomas treated. It is the involvement of the intratemporal ICA and the infiltrative nature of the pathology that dictates the surgical approach. While it is true that some smaller tumors could be removed this way [17], it is incorrect to apply the principle for all classes of TJPs. The involvement of the intratemporal ICA and the infiltrative nature of the pathology must dictate the surgical approach. Hypotympanic approaches to small C1 tumors are employed by some surgeons for minimal jugular fossa involvement, but the risk of limited ICA exposure and the lack of proximal and distal control of the jugulosigmoid system can be significant [18–21]. The assertion that a purely infralabyrinthine approach , with preservation of the middle ear and the FN left in situ, is a safe and effective approach for most TJP is erroneous as limited anterosuperior exposure creates the risk of residual tumor and the potential for catastrophic injury to the ICA. These approaches that are essentially a variation of the petro-occipital trans-sigmoid approach certainly have their indications and are suitable for addressing minimally invasive and minimally vascularized jugular fossa pathology. They can also be considered for early class C1 TJPs, with predominantly posterior disease, and class B3 tumors [22]. The majority of TJPs, which are in close proximity to the ICA, require an ITFA to facilitate safe removal of the tumor [22, 23]. Circumferential dissection of the FN in its vertical segment with preservation of a thin bony coverage is referred to as a fallopian bridge technique [23, 24]. This technique allows access to the jugular bulb on either side of the FN [25] and can be applied with either preservation or elimination of the EAC and middle ear structures [23]. However, this technique still limits anterior control, and there remains a small risk of FN injury due to possible fracture of the fallopian bridge.

FN mobilization also allows safe removal of the styloid process and complete removal of the tympanic bone, which is invariably infiltrated in TJP. This would provide for optimal control of the upper parapharyngeal space, the ICA, and the LCN. The true results of facial function following rerouting must be analyzed in comparison to tumor recurrence rates and associated morbidity when the FN is not mobilized. We strongly feel that the relatively mild facial dysfunction associated with anterior rerouting from the geniculate ganglion is a small price to pay for improved access which provides definitive vascular control and ultimately reduces recurrence rates [2].

A purely retrosigmoid approach that is commonly used to manage LCN schwannomas and posterior fossa meningiomas does not allow safe removal of tumor that extends into the jugular foramen and is therefore a common cause for recurrence. Hence a transjugular approach is usually necessary in the management of jugular foramen pathology and is essential to allow excision of lesions that have true extension into the jugular foramen and further down into the parapharyngeal space [26]. It is generally in the rare case where sacrifice of the jugulosigmoid system is not possible as detected on preoperative assessment, in which conservative measures like a retrosigmoid approach may be considered.

Preservation of the jugulosigmoid system has been also described for jugular fossa pathology, when it has been compressed but not invaded. The suprajugular approach , essentially a presigmoid and infralabyrinthine approach , involves dissection of the infralabyrinthine air cell tract, with an opening of the dura between the labyrinth and the jugular bulb, allowing improved access up to the jugular foramen [27]. The pneumatization pattern of the temporal bone plays a large role in the amount of room that can be gained in this area. Evidently, while preservation of the jugulosigmoid system has been described for dumbbell tumors of the LCN [28], this might not allow complete removal of the tumor. As mentioned, a transjugular approach is usually necessary in management of JF pathology and is essential to allow excision of lesions that have true extension into the jugular foramen and further into the parapharyngeal space [26]. It is only in the rare case where sacrifice of the jugulosigmoid system is not possible as detected on preoperative assessment, in which these more conservative measures should be considered.

The use of the far or extreme lateral approaches with various extensions has been proposed for accessing the jugular fossa to preserve the middle ear and leave the FN in situ and even avoidance of drilling the petrous bone at all [10, 13, 15, 29–33]. It must be remembered that the far-lateral approach was initially developed to access lesions of the craniocervical junction and ventral lower brain stem in order to limit brain stem retraction and pathology without significant involvement of the temporal bone [27, 30, 34, 35]. However, this approach by itself limits the control of the intrapetrous carotid and the ability to widely remove infiltrated bone. The real advantage in this approach lies in improved exposure of the intradural extension. In summary these techniques are useful adjuncts to the ITFA, especially in C2–C4 tumors.

The subtemporal-infratemporal approach was initially described by Sekhar for the removal of extradural lesions of the mid to upper clivus and involvement of the petrous ICA [36]. It is a preauricular approach that, when used in isolation, represents an anterior approach to the jugular fossa. While it avoids the necessity to reroute the FN, it requires resection of the mandibular condyle and mobilization of the petrous ICA and gives limited exposure to the bony margins of the jugular fossa. It has no role as a sole approach for lesions of the jugular fossa. In combination with an IFTA, it is essentially the same as an ITFA type B and is employed to control the area medial to the horizontal intrapetrous ICA [5, 37]. The classic ITFA type A is the most favored approach for class C1 and certain class C2 tumors, and the ITFA type A with extensions can be used to manage class C2–C4 tumors.

This approach is designed to allow access to the jugular foramen area, the infralabyrinthine and apical compartments of the petrous bone, the vertical segment of the internal carotid artery, and the upper jugulocarotid space. The approach is designed primarily for extensive extradural lesions involving these areas. The key point in this approach is the anterior transposition of the FN to provide optimal control of the targeted areas. The other structures that prevent lateral access to these areas are shown in Fig. 8.1c. Besides the FN they include the tympanic bone, the digastric muscle, and the styloid process. These structures are removed to allow an unhindered lateral access.

A postauricular skin incision is performed (Fig. 8.2). A small, anteriorly based musculoperiosteal flap is elevated to help in closure afterward. The external auditory canal is transected and closed, and the FN is identified at its exit from the temporal bone (Figs. 8.3 and 8.4). The main trunk is found at the perpendicular bisection of a line joining the cartilaginous pointer to the mastoid tip. The main trunk is traced in the parotid until the proximal parts of the temporal and zygomatic branches are identified. The posterior belly of digastric muscle and the sternocleidomastoid muscle are divided close to their origin. The internal jugular vein and the external and internal carotid arteries are identified in the neck. The vessels are marked with umbilical tape. The skin of the external auditory canal, the tympanic membrane, the malleus, and the incus is removed. A canal wall down mastoidectomy is performed, with removal of the bone anterior and posterior to the sigmoid sinus. The FN is skeletonized from the stylomastoid foramen to the geniculate ganglion. The last shell of bone is removed using a double-curved raspatory . The suprastructure of the stapes is preferably removed after cutting its crura (Fig. 8.5). The inferior tympanic bone is widely removed, and the mastoid tip is amputated using a rongeur. A new fallopian canal (arrow) is drilled in the root of the zygoma superior to the Eustachian tube (Fig. 8.6). The FN is freed at the level of the stylomastoid foramen using strong scissors. The soft tissues at this level are not separated from the nerve (Fig. 8.7). The mastoid segment is next elevated using a Beaver knife to cut the fibrous attachments between the nerve and the fallopian canal. The tympanic segment of the nerve is elevated carefully, using a curved raspatory, until the level of the geniculate ganglion is reached. A non-toothed forceps is used to hold the soft tissue surrounding the nerve at the stylomastoid foramen , and anterior rerouting is carried out (Fig. 8.8). A tunnel is created in the parotid gland to secure the transposed nerve (Fig. 8.9). The tunnel is dosed around the nerve using two sutures. A closer view shows the FN in its new bony canal, just superior to the Eustachian tube. The nerve is fixed to the new bony canal using fibrin glue (Fig. 8.10). Drilling of the infralabyrinthine cells is completed, and the vertical portion of the internal carotid artery is identified (Fig. 8.11). The mandibular condyle is separated from the anterior wall of the external auditory canal using a large septal raspatory. The Fisch infratemporal fossa retractor is applied, and the mandibular condyle is anteriorly displaced, with care being taken not to injure the FN. The anterior wall of the external auditory canal is further drilled, thus completing the exposure of the vertical portion of the internal carotid artery. A small incision is made in the posterior fossa dura just behind the sigmoid sinus, through which an aneurysm needle is passed. Another incision is made just anterior to the sinus to allow for the exit of the needle (Fig. 8.12). The sinus is closed by double ligation with a Vicryl suture (Fig. 8.13). Suture closure of the sinus, however, may lead to gaps in the dural incision, with a higher risk of cerebrospinal fluid leakage postoperatively. Alternatively, the sigmoid sinus can be closed with Surgicel extraluminal packing (Fig. 8.14). The structures attached to the styloid process are severed. The styloid is fractured using a rongeur and is then cut with strong scissors (Figs. 8.15 and 8.16). The remaining tough fibrous tissue surrounding the internal carotid artery at its ingress into the skull base is carefully removed using scissors (Fig. 8.17). The internal jugular vein in the neck is double ligated and cut or closed with vascular clips (Fig. 8.18). The vein is elevated superiorly, with care being taken not to injure the related lower cranial nerves (Figs. 8.19 and 8.20). In cases in which the 11th nerve passes laterally, the vein has to be pulled under the nerve carefully to prevent it from being damaged. If necessary (as in the case of TJPs), the lateral wall of the sigmoid sinus can be removed (Fig. 8.21). Removal continues down to the level of the jugular bulb. The lateral wall of the jugular bulb is opened. Bleeding usually occurs from the apertures of the inferior petrosal sinus and the condylar emissary vein. This is controlled by Surgicel packing (Fig. 8.22). If there is limited intradural extension, the dura is opened without injury to the endolymphatic sac (Fig. 8.23). Figures 8.24, 8.25, and 8.26 show the view after the dura of the posterior fossa has been opened. At the end of the procedure, the Eustachian tube (Fig. 8.27) is closed by a piece of muscle. The dural opening is closed by a muscle plug or with only abdominal fat. We never use a rotated temporalis muscle (as suggested by Fisch) in order to avoid aesthetic problems, but the sternocleidomastoid muscle and the digastric muscle are sutured together, and the temporalis muscle is left in its place.

Based on the IFTA approach, various extensions can be added depending upon the extent of the pathology. The standard extension we use is a transcondylar-transtubercular extension for C2–C4 tumors (Fig. 8.28). This allows additional posteroinferior and medial access to the jugular fossa, widening the exposure, thus facilitating venous and neural control. The widened angle also affords better access to the petrous apex, medial to the carotid artery. Very rarely a far lateral is employed with full exposure of the vertebral artery (Fig. 8.29). The use of a translabyrinthine extension is occasionally required for otic capsule involvement. A modified transcochlear approach is uncommonly required to access petrous apex, clival involvement, and infratemporal fossa involvement.

The classic infratemporal fossa approach type A of Fisch permits only superior and anterior exposure of the jugular bulb and is indicated for class C1 and certain C2 tumors. For larger tumor such as class C2, C3, and C4 tumors involving the lower cranial nerves, a transcondylar-transtubercular extension is required in addition to the classic infratemporal fossa approach type A. This extension facilitates inferomedial access to the jugular bulb above the lateral mass of the atlas and occipital condyle (Figs. 8.30 and 8.31).

As described in the previous pages, the ITFA type A approach is performed. The transcondylar-transtubercular approach begins with the identification of the splenius capitis muscles . The posterior fossa dura is uncovered toward the occipital skull base in order to start drilling of the jugular process and occipital condyle. The drilling of the jugular process is commenced followed by the identification and drilling of the occipital condyle superior to the atlanto-occipital joint posteromedial to the jugular bulb (Figs. 8.32 and 8.33) . The hypoglossal canal is then identified between the jugular tubercle and occipital condyle above the vertebral artery, if indicated (Figs. 8.34, 8.35, 8.36, 8.37, 8.38, and 8.39).