3.1 Transoral/sublabial approach

For benign lesions of the maxillary sinus, a transoral approach allows for easy access with minimal morbidity. The soft-tissue approach is usually combined with an osteotomy/ostectomy of the anterior maxillary sinus wall. For treatment of benign conditions, the bone is replaced during wound closure. In case of invasive pathologies or conditions which result in erosions of the anterior sinus wall, the wall may be replaced with a titanium mesh ( Fig 3.1-2 and Fig 3.1-3 ).

The sublabial approach provides excellent exposure to tumors of the maxillary alveolus ( Fig 3.1-4 ).

3.2 Midface degloving approach

Many lesions involving the maxilla and central midface can be removed via midfacial degloving approaches. There are some limitations, for example, when the disease extends medially superiorly or wraps around the orbital rim. This approach provides excellent exposure to both sides of the face and nose. It allows access to the pterygomaxillary space and can be enhanced by using endoscopes and image guidance. The addition of these enhancements benefits in the complete removal of lesions involving this region (ie, neurogenic tumors of cranial nerve V or juvenile angiofibromas). This approach also provides access to the pterygoids in the posterior maxilla, so osteotomies can be performed when performing orbit-sparing maxillectomy procedures. These osteotomies are combined with palatal osteotomies and anterior maxillary osteotomies (nasomaxillary and zygomaticomaxillary) and division of the soft palate attachment to the hard palate to allow en bloc removal of the maxilla ( Fig 3.1-5 ).

3.3 Transpalatal approach

Transpalatal approaches have limited use as stand-alone approaches. They may be combined with resections of the alveolar process for tumors involving the premaxilla, alveolus, and anterior floor of the nose. They may also be combined with osteotomies of the attachments to the septum or maxilla depending on tumor location to release the superior attachments. Obviously, the extent or resection is dependent on the size and location of the tumor.

Transpalatal approaches for the pituitary have also been described, but have mostly been replaced by transnasal microscopic and transnasal endoscopic approaches. Likewise, transpalatal approaches may provide primary or extended access to the nasopharynx as well as to high anterior cervical fusions. Generally, separation of the soft palate with (temporary) resection of the posterior hard palate gives more restricted access than if one separates the soft and hard palate, and then divides the soft palate in the midline. Care must be taken to preserve the vascular supply of the posterior soft palate. Extensive cautery lateral to the midline is not advised and careful retraction of the palate with stay sutures is preferable to overzealous use of self-retaining retractors. This approach is seldom needed and is best performed by an experienced craniomaxillofacial surgeon to minimize morbidity. Most lesions can be removed by other approaches especially when enhanced with endoscopic image guidance.

3.4 Transoral approach in combination with Le Fort I osteotomy

A Le Fort I osteotomy, usually done from an upper buccal/ sublabial incision, with down fracture of the inferior part of the maxilla, provides good access to the posterior nasal cavity and epipharynx, especially for vascular lesions which may require good access for bleeding control. For this approach and osteotomy, the osteotomy line in the maxilla is outlined, the anterior and lateral maxillary pillars are preplated. The miniplates are then removed, the osteotomy and down fracture are performed, and the lesions treated as indicated. After that the inferior portion of the maxilla is repositioned and fixed with typically four miniplates along the anterior and lateral pillars of the midface, as it is done in orthognathic surgery ( Fig 3.1-6 ).

3.5 Transfacial approaches

Lateral rhinotomy approach

A transfacial approach combined with a lateral rhinotomy is an excellent approach for tumors involving the nasal cavity. This allows exposure of the entire nasal cavity. Superiorly, this extends to the skull base and inferiorly to the floor of the nose. All three turbinates are also exposed. The lateral rhinotomy is still the preferred approach for tumors involving the mucosa and/or cartilage of the membranous collumella, ala and dome of the nose ( Fig 3.1-7 ).

3.6 Weber Ferguson ( Dieffenbach Weber) approach

The Weber Ferguson approach is indicated as access for tumors involving the maxilla extending superiorly to the infraorbital nerve and into the orbit. It provides a wide access to all areas of the maxilla, nose, and orbital floor. The incision line is drawn through the vermillion border, along the filtrum of the lip, extending around the base of the nose (or entering the nostril floor for a better esthetic result) and along the facial nasal groove (in the border of both esthetic units). It then extends infraorbitally 3–4 mm below the cilium to the lateral canthus. The incision can be extended laterally or superiorly as necessary for tumor removal ( Fig 3.1-8a-k ).

3.7 Access through defects after tumor ablation

Besides the traditional transfacial approaches, in scenarios where skin resection because of tumor invasion is required, this may provide good and direct access to the underlying facial bones and midface cavities such as the sinuses, nasal cavities, and orbits.

3.8 Endoscopic approaches

Open approaches are consistent with the variety of clinical scenarios that patients present to surgeons, but open approaches to the midface in combination with osteotomies can result in substantial morbidity for patients. This has engendered an expanding interest in the development of minimally invasive endoscopic, endoscopically assisted, and image-guided approaches.

Today many midface lesions can be treated via transnasal endoscopic procedures. Extensions of these procedures may also provide access to the skull base, orbit and frontal sinus. Better visualization with potentially less wide and disruptive exposure can facilitate surgical removal with less surgical morbidity. They have enhanced application when coupled with image guidance systems. They can enhance traditional approaches to assess disease extension, provide improved visualization, and provide better assessment of the complete removal of the process being treated (image guided) ( Fig 3.1-9 ).

Excellent examples of the application of modern imageguided resection techniques to neoplastic processes are being observed especially in the treatment of juvenile angiofibromas, inverted papillomas, and neurogenic tumors. Rates of recurrence and operative complications following endoscopic or endoscopic-assisted resection of juvenile angiofibromas now approximate that observed following traditional open operations. This is also true for removal of inverted papilloma and several other neoplasias involving the maxilla. The older paradigm of en bloc removal appears less rigid. Indeed, what is required is complete removal. Furthermore, the innovation of intraoperative image guidance systems used in endoscopic approaches has offered surgeons improved real time anatomical localization of their resection. This allows for complete endoscopic resection of technically challenging lesions with less potential morbidity resulting from injury of vital structures. Other applications for endoscopic image-guided approaches include medial maxillectomy for inverted papilloma, and maxillary division fifth nerve neuromas. These techniques may also be used to assist in placement of implants for trauma, treatment of exophthalmos, optic nerve decompression and cerebrospinal fluid leak repair. Importantly, it cannot be overstated that the guiding principles of endoscopic intervention should mirror those of traditional approaches to midface pathology; achieving adequate exposure as to allow for the safe and complete excision of all involved tissue is critical.

The nature of the lesion also determines whether endoscopic approaches can be used. Traditional anterior transmaxillary approaches are still required for more extensive malignant processes, which may erode through the posterior or lateral table of the maxilla, floor of orbit, and alveolus. Traditional osteotomies are commonly used in the treatment of malignant tumors and removal of hard tissues (bone tumors, teeth). Transmaxillary approaches may also provide access to lesions or disorders involving the orbit and nasopharynx. Frequently in using transmaxillary approaches for tumors not involving the anterior bony structures, the anterior bone may need to be osteotomized and replaced at the end of the ablative procedures providing better postoperative cosmetic results. The surgeon must use the approach which best addresses the patient’s disease without compromise in removal or to function and appearance.

Ultimately, the surgeon’s decision regarding whether to implement an endoscopic approach hinges on both their individual technical skill set, as well as whether complete resection can be accomplished using a minimally invasive approach. Cases must be carefully selected, and patients always counseled about the potential need for a more radical approach if their tumor is not amenable to endoscopic resection. To this end, a surgeon must always remain aware of the potential intraoperative discovery of unanticipated disease extension. Such situations may mandate modification of the operative plan, requiring a more extensive resection including for instance orbital exenteration. Likewise, an experienced team is required to provide optimal outcomes, treatment for malignant tumors is best discussed and consented in a tumor board.

4.1 Maxillectomy with orbital preser vation

In extended maxillary defects, in addition to the considerable task of restoring oral functions, reconstitution of an inferior orbital wall and zygoma become a paramount consideration ( Fig 3.2-6 ). Without adequate support of the orbit, enophthalmos, hypophthalmos, and diplopia may result. Reconstruction of the orbital floor is necessary to prevent dystopia and to preserve eye function postoperatively. The reconstructive tasks for this defect are, therefore, technically more challenging than when the orbital contents have been resected. Soft-tissue pedicled flaps, such as the temporalis flap rotated through the defect from the osteotomized zygomatic arch, are useful in patients unable to undergo free tissue transfer. The addition of vascularized calvarial bone to the temporalis flap may also provide bone for orbital support in these patients but the geometry of getting the bone and soft tissue each into the right place may be difficult to accomplish [Parhiscar et al, 2002]. Access to the orbital floor and infraorbital rim to insert temporalis flaps requires at least a partial resection of the lateral maxilla, which may weaken the important zygomaticomaxillary buttress. However, this flap places the facial nerve at risk, particularly in the upper division, and results in an unnatural appearing temporal depression. This could be an advantage in situations where just thin bony reconstruction is needed with minimal soft-tissue bulk. Given that this is rarely the case in total maxillectomy defects, this option can be combined with other soft-tissue flaps that could then provide bulk and be fashioned independently from the bony reconstruction.

Because of the volume required to fill the midface contours, many authors have recommended soft-tissue free flaps to obtain a sealed palate and achieve an esthetically satisfactory recontouring of the face and cheek soft tissues [Marshall et al, 2003; Browne et al, 1999; Cordeiro et al, 2000; Cordeiro et al, 2000]. Preference for fat, fascia, and skin as donor material limits the unpredictable atrophy (30–90%) associated with denervated muscle-alone. Soft-tissue-alone reconstructions, however, do not address the maxillary bony skeleton, particularly the orbit, zygoma, and alveolus. Nonvascularized bone or alloplasts have been advocated to improve globe position and bone support, but bone may undergo substantial resorption ( Fig 3.2-7a–b ). The remainder of the defect is filled with vascularized free tissues ( Fig 3.2-7c ). Muscle-alone flaps should be avoided as they do not provide a lasting solution because of atrophy.

Vascularized osteomusculocutaneous free flaps have the advantage of better infection resistance than nonvascularized bone graft reconstructions and are better able to maintain bony volume. For total maxillectomy defects with orbital preservation, the subscapular system of flaps, while technically more complex, offers perhaps the greatest versatility in flap reconstruction [Swartz et al, 1986; Uglesic et al, 2000]. Replacement of the alveolar arch inferiorly with the lateral scapula (supplied by the circumflex scapular artery) and the orbital floor and rim with the scapular tip (supplied by the angular branch of the thoracodorsal artery) suits this reconstruction need well ( Fig 3.2-8 ). The thoracodorsal artery supplies the latissimus dorsi muscle and overlying tissue, which may be harvested partially or completely for a wide range of soft-tissue reconstructive needs. Furthermore, each of the two components of this flap may be rotated independently of each other. In the series by Triana et al [2000], various flaps based on the subscapular system of vessels were used to reconstruct maxillectomy defects in ten patients. Dental and/or orbital restoration was performed in four of these patients with the use of osseointegrated implants. Schliephake [2000] found that it is difficult to tailor the bone in a fashion that simultaneously restores the malar prominence, the infraorbital rim, and the maxillary wall, and at the same time place the lateral border of the scapula in an appropriate position for placement of these implants. Miles et al [2011] have described the use of the vascularized scapular tip flap to restore the palate or the zygomatic contour with the scapular soft tissue (fat, fascia, and skin) filling the remainder of the maxillary defect. The scapular bone may not always be suitable for placement of osseointegrated implants, unless secondary bone augmentation is performed. A relative disadvantage in the use of the subscapular system include challenges to position the patient to harvest the flap simultaneously with the extirpative procedure, difficulty in orienting the bone to provide orbit, zygoma, and alveolar reconstruction and the relatively short pedicle length.

The fibular flap has sufficient bone stock and a soft pliable skin paddle that can be used for either intraoral and/or cutaneous reconstruction ( Fig 3.2-9 ). Futran et al [2002] used the revascularized fibular osteocutaneous free flap in seven patients with total maxillectomies and orbital preservation. Superior and inferior bony support was accomplished, and cosmesis was only considered fair because of flattening in the midface. In comparison one patient in this series whose flap failed and ultimately used a prosthesis, was noted to have poor cosmesis. Osseointegrated implants were placed or planned in this entire group. The fibula bone stock is more reliably implantable than the scapula. This represents an advantage of the fibula over the scapula for this defect, although cosmesis favors the scapula.

The iliac crest free flap provides an excellent bone source for palate and maxillary reconstruction [Brown, 1996; Genden et al, 2001] ( Fig 3.2-10a ). A single block can restore the alveolus, zygomatic prominence, and infraorbital rim. This allows for excellent restoration of structure to support both the globe and a dental prosthesis ( Fig 3.2-10b–e ). It is harvested with the internal oblique muscle that restores the palatal mucosa. The disadvantages of using this flap for the maxilla are its potentially excessive bulk, limited soft-tissue mobility in relationship to the bone and short pedicle length.

4.2 Maxillectomy with orbital exenteration

When tumor resection extends from tongue to supraorbital rim, reconstructive options depend on the amount of remaining dentition. If adequate teeth and alveolar arch remain, a prosthesis may be used. The use of a prosthesis that spans the defect from the oral cavity to the orbit is subject to cheek retraction over time and poor fit as well as the distracting appearance of an unblinking, expressionless eye. These defects provide an additional challenge to the prosthodontist because of the large amount of associated dead space that is created. Reconstruction is usually ideally accomplished through the use of a bulky soft-tissue free flap, such as a rectus abdominus, latissimus dorsi or anterolateral thigh flap to fill the midface volume, including the orbit ( Fig 3.2-11a ). These flaps can be supplemented with separate free nonvascularized bone grafts for additional structural support when the zygomaticoorbital complex is removed as part of the resection. This complex reconstruction in one study resulted in a fair cosmetic result in 46% of patients, normal or near-normal speech in 77%, and limitation to a soft diet in 54% [Cordeiro et al, 2000]. To achieve adequate bone volume for the infraorbital and zygomatic region as well as the alveolar arch, any of the bony options described above can be used but adequate soft tissue must be harvested to obliterate and/or line the orbital component of the defect.

In those cases where there is intracranial communication, the skull base must be sealed as well and cranial protection provided. The advantages of autogenous tissue to seal the skull base include its durability and viability.

4.3 Total maxillectomy

In individuals undergoing total maxillectomy, defects are created with insufficient retentive surfaces and without remaining dentition to support a conventional prosthesis. It is therefore preferable to reconstruct the area with vascularized bone and soft tissue to allow for closure of the palate, and a stable base for osteointegrated dental implants. Ultimately an implant-borne prosthesis will be added. The main determinants of which flap to use are the size of the palate’s defect as well as whether there are additional areas that need bony support, such as the orbital floor or the malar eminence. Futran et al [2002] reported a series of 27 consecutive patients receiving a fibula free flap for reconstruction of maxillectomy defects involving the palate that were not amenable to an obturator. In this group, 18 patients received implants with fabrication of prostheses. Four patients had wound complications managed successfully with local wound care and there was one flap loss. All patients had intelligible speech over the telephone and all were able to resume an oral diet, with 14 patients on a regular diet and 13 using soft diet. The fibula free flap has a large amount of available bone, long pedicle length and minimal donor site morbidity and is the most popular choice for total maxilla reconstruction. Scapula flaps can be a versatile option for more complex defects but disadvantages include somewhat thinner bone that does not as reliably accept implants. Simultaneous midface surgery and flap harvest are not feasible. The iliac crest is less frequently used but provides excellent bone stock, though it has excessive bulk and a short vascular pedicle. Nonvascularized free bone grafts when used in combination with softtissue flaps can provide structure to the face, improving contour but they have not been shown to reliably accept dental implants and in addition resorb substantially and often almost completely.

An example of a total maxillectomy requiring fibula free flap reconstruction is shown in Fig 3.2-12a–k . The maximal length of bone is harvested, and osteotomies are then performed proximally and distally to allow for shaping of the neo-maxilla ( Fig 3.2-12e ). The vascular pedicle is then passed through a tunnel created in the cheek, into the neck for microanastomosis. This tunnel is usually made in a subcutaneous plane superficial to the facial nerve branches and should be able to accommodate at least two fingers to ensure adequate space for the vessels. This is simpler than going beneath the facial musculature and also avoids potential kinking of the vessels. Miniplates are then used to secure the fibula to the medial and lateral buttresses of the remnant midfacial skeleton ( Fig 3.2-12f ). The skin paddle of the fibula is then inset to reconstruct the mucosa of the palate ( Fig 3.2-12g ). Delayed placement of osteointegrated implants, a prosthesis, and a longlasting stable result is shown in Fig 3.2-12h–k .

4.4 Donor site management

Management of each free flap donor site has been previously described in the literature. In short, the radial forearm free flap donor site should be closed with a split thickness skin graft and a bolster placed over the graft. The arm is then casted or placed in a volar splint for 7 days before removal to improve graft take. If bone is taken and the radius plated, arrange an appropriate follow-up with an orthopedic or hand specialist. After a fibula free flap, the donor lower leg should be cast with the ankle at a right angle for 5 days or 7 days if a skin graft is used at the donor site. The patients can then touch-down their body weight as tolerated. After the cast is removed, they can ambulate and work with physical therapy to optimize leg function. A splint should be placed to keep the foot at 90° to the leg when in bed. Flaps from the subscapular system require no particular rehabilitation care but closed suction drains should remain until a minimal output is achieved over several days to avoid seroma formation (minimal output less than 30 cc per day). Rectus abdominus and iliac crest donor sites require that the patient not strain or lift heavy objects for at least 2–4 weeks to avoid hernia formation.

1.1 Introduction and history

In addition to the eyeball, the orbit with its bony walls contains the eye muscles and nerves, fatty tissue and glandular structures of all germ layers. Therefore, various types of tumors can be found in the eye socket that are often associated with complex treatment requirements.

The most common symptom of orbital masses is exophthalmos. In addition to the visible protrusion of the globe, double vision, motility disorders, and a reduction in visual acuity, lateral and/or medial displacement and rotation of the eyeball may indicate an orbital tumor. Until the 19th century, orbital tumors, if they were operated on at all, were almost always treated by exenteration regardless of their pathology.

Advances in anesthesia and the introduction of osteotomy techniques have expanded the options for operations inside the orbit. In 1888, Krönlein was the first to describe the temporary resection of the lateral orbital wall for the removal of a dermoid while maintaining the eyeball. The mobilized piece of bone pedicled on the periosteum healed without any problems after tumor removal [Krönlein, 1888].

In 1941, Dandy could extirpate a meningioma in the optic canal for the first time via a transcranial access route after removing the orbital roof. Dandy subsequently proclaimed that this access route should be used for all orbital tumors [Dandy, 1941]. He even performed the first cranial bone graft, which he used in reconstruction.

Today, if an orbital lesion is suspected, operations can be planned based on computed tomographic (CT) scans and magnetic resonance imaging (MRI) procedures. The localization and size of the tumor and its anatomical link to the adjacent structures determines the most appropriate approach for the operation on a case-by-case basis. The globe is preserved if possible. The use of intraoperative navigation techniques can facilitate the removal of orbital tumors while maintaining function.

1.2 Etiology and epidemiology

The basis for exophthalmos in almost 50% of cases is endocrine orbitopathy, followed by inflammatory orbital pseudotumors. With few exceptions, the disease occurs on both sides. In contrast to this, orbital pseudotumors are responsible for approximately 16% of all one-sided cases of exophthalmos [Jones et al, 1979].

True orbital tumors are rare. The incidence varies between 3 and 20 cases per 1,000,000 people [Eldrup-Jörgensen, 1970; Henderson, 1987].

Epithelial neoplasias may originate from the conjunctiva or the lids but also from the lacrimal glands or the choroid. In terms of numbers, adenomas are the most common epithelial lacrimal gland tumors but carcinomas and other malignancies are also observed. Epidermoid cysts are typically localized in the orbit. Benign neurogenic tumors in the orbit that arise from the outer germ layer are also observed.

Mesenchymal tumors can originate from the extraocular muscles, the fatty tissue, the orbital vessels and more rarely the orbital bones. Here, the diagnostic spectrum ranges from benign cavernous angiomas, lipomas and osteomas to sarcomas and malignant lymphomas.

The most important and largest group of malignant neoplasias during childhood are rhabdomyosarcomas. However, benign orbital diseases and orbital dermoid are even more common in numbers and can make operations during early childhood a necessity.

In adults, endocrine orbitopathy is the most common orbital mass. Malignant lymphomas are observed frequently in patients older than 60 years [Shields et al, 2008].

In addition to this, orbital metastases and various primary tumors are also observed. Extension of sinonasal carcinomas may happen and can penetrate the orbit from the maxillary, ethmoid and/or frontal sinuses. Metastases, for instance from breast carcinomas or melanomas, are also observed and sometimes first occur more than 10 years after the primary treatment as an isolated manifestation.

2.1 Interdisciplinary treatment concepts

The treatment of orbital masses and tumors should be an interdisciplinary task. Ophthalmology is usually the first point of contact for a patient affected by a tumor of the orbit. Frequently, an interdisciplinary treatment concept involves surgical and nonsurgical specialties. Common collaboration partners for orbital surgery includes, neurosurgeons, craniomaxillofacial surgeons, radiation oncologists, and medical oncologists in addition to ophthalmologists.

2.2 Presurgical diagnostics

The clinical symptoms of orbital tumors are often nonspecific and only rarely indicative of the diagnosis. Conclusions can be drawn about the location of the tumor based on a visible displacement of the globe, motility disorders, double vision, ocular pain or a reduction of visual acuity.

A complete ophthalmological evaluation includes assessment of visual acuity, motility and visual field testing. If applicable, it can be expanded by the determination of visually evoked potentials and eye pressure measurements that provide important results relating to the preoperative functional status of the diseased orbit. The patency and function of the lacrimal system should also be evaluated, as should ocular lubrication.

The CT and/or MRI show the exact location of the tumor and are indispensable in most cases.

2.3 Treatment principles

With the aid of modern imaging techniques for preoperative localization, the most gentle and accurate operative access route for each individual case can be determined and the risk of complications significantly reduced. A clear operative field with a wide osteotomy of the orbital walls prevents unnecessary intraoperative compression of the orbital contents, and significantly reduces postoperative dysfunction. It is also necessary to avoid long periods of traction on the globe or orbital muscles during the operation.

3.1 Biopsy and surgical planning

The confirmation of a diagnosis by means of a biopsy before the planning of a specific treatment is standard of care.

However, in the case of tumors in the retrobulbar area, it can be necessary to use complicated access routes to harvest representative tissue. The surgeon is then faced with the difficult decision of whether to remove the tumor entirely when first accessing the area. The depiction of the lesion in the MRI/CT image performed to plan the operation is also used for guidance. When there is a clear delineation between the tumor and the surrounding structures, an attempt should be made at primary total extirpation. This applies to most cavernous angiomas and many neurofibromas in the orbit.

An initial biopsy is a contraindication in the case of pleomorphic adenomas of the lacrimal gland as a significantly increased rate of recurrence is to be expected in the case of prior sample excision [Front et al, 1978; Henderson, 1987; Wright et al, 1992].

If epidermoid or dermoid cysts are expected because of the clinical presentation and imaging, the mass should be enucleated in total because biopsy may lead to a leakage of the contents of the cystic lesions and subsequent contamination of the orbital tissues. This may result in pronounced orbital inflammation and an increased rate of recurrence despite the subsequent extirpation of the cysts [Bartlett et al, 1993; Shermann et al, 1984].

3.2 Surgical approaches and techniques

3.2.1 Orbitotomies without osteotomy

Anterior orbitotomies with no additional osteotomies are suitable for sample biopsies and for encapsulated tumors in the anterior third of the orbit and with some limitations in the central third. In anterior orbitotomies without osteotomy of bony orbital walls, a distinction is made between transseptal and transperiosteal access routes.

In the transseptal approach, the fibers of the orbicularis oculi muscle are split in the direction of flow via an incision in the natural creases of the lid. Then the orbital septum is examined and opened ( Fig 3.3-1 ). This operative technique is particularly suitable for dermoid cysts during childhood that are often localized in front of and behind the orbital septum. Difficulties can arise because benign tumors slide back into the depths of the orbit when an attempt is made to remove them, so it can be difficult to grip them.

Transperiosteal approaches for sample biopsies of undefined tumors are an alternative approach in case the mass is not located close to the skin. With this approach, the contact area between the anterior end of the orbit and the lids remain undisturbed.

The skin incision is either made as an inferiormedial brow, lateral brow, orbital rim, mid eyelid, subciliary, or transconjunctival. The latter can, if necessary, be extended by a lateral canthotomy ( Fig 3.3-2 ). The orbital septum remains intact in this process. After the incision of the periosteum, the orbital wall close to the tumor is exposed, the periorbital tissue is split in a sagittal direction and the orbital tumor is exposed. To do this, a sufficiently large incision must be made in the periorbital tissue (normally 90° of the orbital circumference). The subsequent closure of the wound is carried out in all anatomical layers in combination with a deep silicone drain.

Pitfalls

In single sample biopsies, the anterior periorbital area should remain intact to prevent a prolapse of the tumor out of the orbit.

3.2.2 Orbitotomies with osteotomy

Without the temporary removal of one or more orbital walls it is difficult to operate adequately on tumors in the central and posterior third of the orbit, if they are located inside the cone-shaped muscles of the orbit. In principle, all osteotomies should be carried out with fine saw blades or piezoelectric devices. The repositioning and stabilization of the osteotomy segment is then carried out using two single microscrews or microosteosynthesis plates 1.0 or 1.3.

3.2.2.1 Lateral orbitotomy

Since lacrimal gland tumors and most primary orbital tumors are both generally located lateral to the optic nerve, this access route frequently offers ideal conditions for removing tumors while maintaining function. In all orbitotomies with temporary removal of the lateral and/or superior orbital wall, a coronal incision is advantageous. The skin incision is taken down to the preauricular region on the tumor side. A subgaleal/epiperiosteal dissection up to approximately 2 cm above the eyebrow is performed ( Fig 3.3-3a ). At the height of the upper edge of the tragal cartilage, the external temporalis muscle fascia is incised and the incision is extended via the crista temporalis through the frontal periosteum to the contralateral side ( Fig 3.3-3b ).

The course of the frontal branch of the facial nerve is localized using an electrical nerve stimulator. Dissection between the layers of the superficial and deep temporal fascia or under the anterior layer of the deep temporal fascia in the subfascial fat and the subperiostal frontal dissection guarantees reliable protection of this nerve and broad subperiostal exposure of the orbital rim. The frontal branch of the trigeminal nerve is then dissected from or released from the supraorbital foramen by means of chisel osteotomy and shifted into the orbit at the same time as the periorbital periosteum is detached (normally 270° of the orbital circumference). The temporalis muscle is released from the crista temporalis in the anterior third of the muscle and deflected in a dorsal (posterior) direction. It is recommended that a small rim of the muscle be left in the muscle’s attachment to the crista temporalis for later suturing of the muscle to its insertion. The temporal fossa is completely exposed including the lateral orbit wall. A slight angular osteotomy is carried out through the lateral orbital rim ( Fig 3.3-4a ) down to the inferior orbital fissure. From there, a separation of the lateral orbital wall as far dorsal as possible in the junction between the lateral orbital wall and the temporal bone is performed. The saw cut runs above the frontozygomatic suture. The osteotomy is completed with osteotomes and the lateral segment of the orbit is temporarily removed ( Fig 3.3-4b ). The surgical assistant controls the orbital penetration depth of the saw blade during the osteotomy and protects the orbital content with a spatula.

3.2.2.2 Extended frontolateral orbitotomy

Tumors located in the intraconal and extraconal regions can be removed in a gentle manner via an extended frontolateral orbitotomy. Depending on the need, the lateral orbitotomy can be extended on an individual basis in a supraorbital and caudal lateral direction. The temporary removal of one or more orbital walls, if applicable with the zygoma and/or parts of the supraorbital edge enables clear and expanded access to the retrobulbar region. In doing this, the osteotomy is guided as a V-shape through the zygoma, and the zygomatic arches are detached from the articular tubercle at the temporomandibular joint. In the supraorbital area, the saw placement is supraorbital through the frontal bone.

3.2.2.3 Inferior orbitotomy

A temporary osteotomy of the infraorbital rim is used to expose tumors in the central and posterior thirds of the orbit caudal to the optic nerve. Above the infraorbital nerve, the bone can be mobilized. If a larger access route is needed, the infraorbital nerve, which runs directly through the operative area, must be completely freed from the mobilized segment ( Fig 3.3-5 ). If necessary in the case of tumor expansion far into the medial/caudal direction, an inferior orbitotomy can be combined with an extended superolateral orbitotomy.

3.2.2.4 Medial orbitotomy

Medial orbitotomies are mostly carried out transnasally or transethmoidally. The operative technique corresponds to that of classic sinus surgery but is always osteoclastic and contains the risk of a postoperative enophthalmos. The indication is therefore present mostly in the case of endocrine orbitopathy, in which the existing exophthalmos should be corrected anyway. An alternative to the transnasal procedure is the transconjunctival/transcaruncular approach. It can be used provided there is strict protection of the nasolacrimal duct and the medial strip attachment ( Fig 3.3-6 ). In combination with a lateral canthotomy, the lower lid is rendered free moving by this access route, which is why the operative technique is often referred to as “swinging eyelid approach” [McCord, 1981; Paridaens et al, 2006]. The resection of the lamina papyracea and the removal of the ethmoid mucosa, while maintaining the nasal ethmoid bone wall, can clearly be carried out in this way in endocrine orbitopathy. The connecting line between the anterior and posterior ethmoidal vessels, which are both coagulated and sharply detached from one another, defines the cranial limit of the decompression. If dissection and resection cranial to this line is performed, there is a risk of injury to the fila olfactoria and for a cerebrospinal fluid leak. The posterior ethmoidal foramen is the anatomical landmark to determine the limit of dorsal resection. As a rule the decompression ends here, as the optic nerve will enter the optic foramen 5 mm behind this point.

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