The frontotemporal region is a complex anatomical area; therefore, it is important to fix some anatomical remarks.

The soft tissue covering this area comprises five layers: skin, subcutaneous tissue, galea aponeurotica, loose connective tissue, and pericranium. These five layers are covered by an outermost horny layer, variable in thickness, while the subcutaneous tissue is made of derma and fatty tissue, which is thicker over the zygomatic arch; therefore, the thickness of the scalp varies from 4 to 9 mm.

In the temporal region, the galea pericranium is called temporoparietal fascia and is considered part of the superficial muscle-aponeurotic system. This fascia is attached in an arched fashion to the superior temporal line, to the lateral surface of the frontozygomatic process and to medial surface of the zygoma. Inside it, it is possible to identify the superficial temporal artery and the frontotemporal branches of the facial nerve.

The loose connective tissue is located directly beneath the fascia and is composed of connective tissue which becomes thin and fatty in correspondence of the zygoma, thus making the first fat pad in continuity with the subcutaneous fat below the zygomatic arch [2].

The pericranium, at the level of the superior temporal line, splits into two layers, a deeper one, beneath the temporal muscle, in contact with the temporal squama, and the other more superficial, covering the muscle and called temporal fascia. Furthermore, this layer splits into two separate laminae, superficial and deep, which enclose the superficial temporal fat pad. Between the fascia and the temporalis muscle, there is another fat pad that forms a sort of pillow, provided of vessels and nerves and variable in thickness, from very thick to extremely thin. Some authors consider another fascia, defined innominate fascia, or parotid temporal fascia closely adherent to the superficial temporal layer [1, 54].

In order to avoid postoperative cosmetic deficits, the knowledge of the anatomy of the superficial temporal artery and the facial nerve is essential.

The superficial temporal artery is a terminal branch of the external carotid artery, running close to the tragus within the subcutaneous tissue and bifurcating in the temporal region 2 cm above the zygomatic arch. The frontal branch gives rise to many twigs in the frontal area and finally anastomoses with the supraorbital artery of the ophthalmic artery. The parietal branch supplies the parietal, temporal, and occipital areas, anastomosing with the contralateral parietal branch and the posterior auricular and occipital arteries. Its collateral arteries are the transverse artery of the face, the temporal artery, and the zygomatic-orbital artery. The superficial temporal artery could be a useful landmark indicating the position of the frontal nerve that runs 1 cm caudal and parallel to its frontal branch [55].

The facial nerve divides into temporal and zygomatic branches within the parotid gland. The temporal branch of the facial nerve is located in the same plane as the superficial fat pad, both being in the subgaleal space; however, the presence of a sizable twig of the middle division of the temporal branch of the facial nerve (frontal ramus) going into the intrafascial space and then entering the frontalis muscle has been described [2]. The temporal branch pierces the parotid-masseteric fascia below the zygomatic arch and then immediately divides into its terminal branches: anterior, middle, and posterior [54]; in particular, the point where the temporal branch of the facial nerve gives off the anterior and middle rami is located 2–2.5 cm anterior to the tragus (range, 1.5–3.5 cm). The anterior ramus innervates the corrugator supercilii and orbicularis oculi muscles, while the middle one (frontal ramus) innervates the frontalis muscle; the posterior ramus, which innervates auricular and tragus muscles, does not have any practical importance in man [2]. In particular the general course of the frontal ramus, as described by Pitanguy and Ramos (Pitanguy line), begins 0.5 cm below the tragus and extends 1.5 cm above the lateral aspect of the eyebrow [38]. At the inferior border of the zygoma, it is deep to the temporoparietal fascia, then becomes superficial to the periosteum of the arch, and at the superior edge of the zygomatic arch, it is found in close proximity to the deep temporal fascia [48]. The branches of the facial nerve and its rami, which are variable in number, cross at the middle third of the zygomatic arch and may cover up more than half the length of the arch [4, 22].

The pterion is a region in the temporal fossa, localized about 4.0 cm above the zygomatic arch and 3.5 cm behind the frontozygomatic arch; it is defined as an H-shaped small circular area made by the junction of four bones: frontal, parietal, temporal, and sphenoid [29, 42, 44]. It is a meeting point of skull base, calvarium, and the skeleton part of facial anatomy and therefore has a different morphology [18]. Murphy defined four types of pteria: sphenoparietal, frontotemporal, epipteric, and stellate; the sphenoparietal and frontotemporal pteria present the straight line between the ends of the suture as the center of the pterion, while for the other types, the center is the smallest circle encompassing the edge of all bones (Fig. 11.5) [33]. This point is a landmark for the anterior branch of the middle meningeal artery, Broca’s motor speech area to the left, insula, and the Sylvian cerebral fissure [50]; the pterion is also commonly used as an important guide for age estimation and sex determination in archeologically and forensic specimens [27].

Once performed, the pterional craniotomy, which would be detailed and described in the next paragraph, and the arachnoidal dissection with microsurgical technique, it is possible to expose and visualize the neurovascular structures of the anterior cranial fossa. Among them it is relevant to focus on the lamina terminalis. It is a translucent whitish membrane, made by a thin sheet of gray matter covered by a pial layer. It is at the base and front of the brain and forms most of the anterior wall of the third ventricle, together with the optic chiasm and the anterior commissure [41]. It is a triangular structure: the height is calculated as the distance between the midportion of the posterosuperior surface of the chiasm and the anterior commissure, while the base is the distance between the medial edges of the optic tracts (Fig. 11.6) [15]. It runs from the midportion of the superior surface of the optic chiasma to the inferior surface of the anterior commissure medially and the pillars of the fornix laterally, leaving a small cleft called optic recess, between the upper half of the chiasm and the lamina. The lamina has not a direct relationship to the hypothalamus, but it is closely laterally related to it [51].

The lamina terminalis cistern is located in the anterior incissural space, above the optic chiasm and delimitated superiorly by the rostrum of the corpus callosum, posteriorly by the lamina terminalis, and laterally by the portions of the medial surfaces of the frontal lobes. Important vascular structures are contained in the lamina terminalis cistern and are intimately related to the lamina terminalis: both A₁ tracts and the proximal A₂ tracts of the anterior cerebral arteries, the anterior communicating artery, perforating vessels, both recurrent Heubner arteries, both fronto-orbital arteries, arteries running to the hypothalamus, and anterior communicating and anterior cerebral veins. In particular, the anterior cerebral artery, in its A₂ portion, passes in front of the lamina terminalis and the anterior wall of the third ventricle, reaching the rostrum of the corpus callosum in the anterior portion of the callosum cistern. The perforating vessels arise from the anterior cerebral and anterior communicating arteries and reach the hypothalamus through the optic chiasm and the infundibulum, or pass through the lamina terminalis to enter the wall of the third ventricle [15]. A pericallosal artery arising from the anterior communicating artery sometimes passes upward in front of the lamina terminalis, reaching the rostrum of the corpus callosum (Fig. 11.7) [3, 15].

The optic chiasm is a quadrilateral X-shaped structure, situated at the bottom of the brain, immediately below the hypothalamus. It is possible to describe three anatomical variations in the relationship between the optic chiasm and the sella turcica: the so-called normo-fixed variant, overlies the diaphragma sellae; the pre-fixed variant, located above the tuberculum sellae; and the post-fixed variant, situated superior to the dorsum sellae [39].

A variety of operative approaches have been described as the optimal treatment for craniopharyngiomas, including the subfrontal, pterional, bifrontal interhemispheric, and transcallosal approaches [17, 28, 46, 52]. All the intracranial approaches are performed with the operating microscope, usually under moderate to high magnification. More recently the extended endoscopic endonasal transsphenoidal approach provides a new option for the treatment of craniopharyngiomas [7, 9, 10, 13, 14, 25]. Surgical adjuncts, including the ultrasonic aspirator and neuronavigation, should be available and utilized when appropriate.

The widely recognized advantage of the frontotemporal craniotomy is the enhanced exposure of deep neurovascular structures, which offers a shorter and wider view of the surgical target.

Moreover, the frontotemporal craniotomy offers the shortest and most direct route to the suprasellar region and, with splitting of the Sylvian fissure, minimizes or eliminates retraction of normal brain [53].

The patient is positioned supine on the surgical table with the legs flexed. The head is turned to the side contralateral to the approach about 30–60°, according to the exposure required, and secured to the Mayfield-Kees pin headrest. The single-pin arm is placed on the homolateral side: we use to fix it behind the ear, above the mastoid process, within the parietal bone. The two-pin arm is fixed on the contralateral site: the anterior pin inside the frontal bone, behind the hairline, near the pupillary line, and the posterior placed over the parietal bone, on the superior temporal line. The neurosurgeon has to prevent any penetration in the temporal muscle, which would increase instability of the head and postoperative displeasure. The vertex of the head is then tilted down 10–15°, so that the malar eminence is almost the highest edge of the surgical field. Once the patient is well fixed to the operating table, it is important to raise the thorax 10–15°, which ensures the reduction of venous distension, since the head is marginally above the level of the heart.

During these procedures the surgeon must not overstretch the neck, to prevent venous drainage damage, as well as of the esophagus and trachea. Moreover, it is important to keep safe the cervical portion of the spine from any extreme rotation.

Correct positioning ensures an optimal viewing angle of the central cranial base, thus minimizing the use of spatulae on the cerebral lobes and providing the surgeon a natural retraction of frontal lobe (falling from the orbital roof) and temporal lobe (coming out from the sphenoid ridge) (Fig. 11.8).

Cautious disinfection of the skin and draping has to be performed before starting surgery.

The skin incision for the standard frontotemporal approach is performed in the standard fashion for a pterional craniotomy as described by Yasargil et al. [54]. A relaxing skin incision should be made in order to avoid inadvertent penetration of the pericranium and temporal fascia over the frontal and the temporal regions, respectively. It starts from the frontal region, and it is made in short segments, using a smooth dissector to prevent damage to the close neurovascular structures. Moreover, we suggest the use of Raney clips to manage the scalp hemostasis.