H. D. Fournier

Surgical anatomy of the petrous apex and petroclival region.

Surgical exposure of the clivus, the ventral or lateral aspect of the brain stem, and all the intradural structures of the petroclival area remains difficult because of the presence of the petrous apex and peripetrous complex. However, a lateral skull base approach to the petroclival area is the most suitable approach if the lesion to be resected lies medial to the fifth nerve, in front of the acousticofacial bundles, extending towards the midline. The purpose of this study is to review the topographic anatomy of the petrous apex and peripetrous structures, with emphasis on the relationships important to the lateral approaches to the petroclival area. Such anatomical knowledge allows us to study the surgical technique, exposure, and pitfalls of the main lateral transpetrosal skull base approaches used to reach the petroclival area.

Anatomy of the arterial vascularization of the lips

The findings from 12 dissections of previously injected facial masks, 8 dissections of the face following intra-arterial injection of a red solution of Latex Neoprene, and a corrosion cast specimen allowed us to study the arterial supply of the lips. The arterial supply of the upper lip arises mainly from the superior labial arteries, but also from the subseptal arteries and from the subalar arteries. There is a figure of 8 shaped anastomotic system between these arteries lying on the upper lip. The arterial supply of the lower lip arises from the inferior labial arteries and from branches of the mental artery. A constant inferior labial arterial network was shown at the level of the lower lip arising in a fifth of cases from a T-shaped inferior labial artery. All these recent anatomic findings help us to improve our understanding of plastic surgery of the lips.

Surgical anatomy of the infratemporal fossa using the transmaxillary approach

Abstract In this study we evaluated the ability of the transmaxillary route to expose the elements of the infratemporal fossa (ITF). Five adult cadaver heads were dissected on both sides, after making a paralateronasal incision. The maxillary branch of the trigeminal nerve served as a superior landmark to progress into the retroantral space and pterygopalatine fossa. The maxillary artery, lateral pterygoid muscle, pterygoid venous plexus, foramen rotundum and foramen ovale were identified. Distances between those elements and angle of approaches of the foramen ovale and foramen rotundum were measured in the horizontal plane. In all cases, the anterior loop of the maxillary artery and the sphenopalatine artery were located in the proximal retroantral fatty space and could be ligated without optic magnification. The maxillary nerve could be followed up to the foramen rotundum at a 44 mm mean distance from the opening. The mean angle of vision to the foramen rotundum was 31°. Under the greater sphenoid wing and lateral to the pterygoid process, desinsertion and partial resection of the lateral pterygoid muscle were required to identify the pterygoid venous plexus and foramen ovale. The pterygoid venous plexus was organized as a compact network of channels between and superior to the muscle fibers it was in close relation with the foramen ovale. Access to the foramen ovale was deep (mean 56 mm) and narrow (20°). Our results indicate that the transmaxillary approach is a minimally invasive procedure that gives an appropriate window to the structures of the retroantral space and to the pterygomaxillary fissure and pterygopalatine fossa. Monitoring of the retropterygoid portion of the infratemporal fossa by this route is inadequate.

Anatomic and radioanatomic study of the lateral genicular arteries: application to prevention of postoperative hemarthrosis after arthroscopic lateral retinacular release

Arthroscopic lateral retinacular release can be complicated by hemarthrosis in 10 to 18% of cases. The vascular structures involved are the lateral vascular pedicles of the knee. This study examines the topography of these pedicles. Anatomic and radioanatomic studies carried out in 50 specimens defined the route of the vascular pedicles at the lateral aspect of the knee. From the measurements carried out, we noted the relative homogeneity of the routes taken by the different proximo-lateral vascular pedicles, which are highly vulnerable, and the variability of the disto-lateral arterial routes. A tracing-paper study identified two distinct routes for the disto-lateral vascular pedicle and evaluated the risk of injury to it in surgical approaches to the lateral aspect of the knee. Finally, the topographic data of the study suggest the possibility of preventive hemostasis of the proximo-lateral pedicle via a minimal approach close to the patella. Furthermore, it seems possible to avoid cutting the disto-lateral pedicle if it is localised by cutaneous trans-illumination at the beginning of the operation.

Persistent sciatic artery: report of an original aneurysm-associated case.

Persistent sciatic artery (PSA) is a rare embryologic abnormality and can sometimes be bilateral. It may be discovered because of a gluteal aneurysm or ischemic or embolic complications in the lower limb. The case we report was a unilateral type III aneurysm-associated PSA. Since the abnormal artery may be the only source of blood supply to the lower limb, a thorough knowledge of the artery and its embryologic origins is essential.

Anatomy of the Orbit and its Surgical Approach

A micro anatomical and surgical study of the orbit was conducted on cadaver specimens. First of all we reviewed the anatomy of the orbit with special emphasis on microanatomical structures. Three neurosurgical approches are then described with all structures encountered along these routes. The superior approach which provides a good access to the superior part of the orbit is the only route which can explore all parts of the optic nerve even in the optic canal. The lateral compartment of the orbit could be exposed by the lateral approach above or below the lateral rectus muscle. It is the only route that could give access to the inferior part of the orbit. The supero lateral approach is the largest route and has advantages of the two preceding routes. It gives access to the superior part of the orbit but not the optic canal and gives also a good exposition to the lateral part of the orbit but less than the lateral route in the inferior part. These approaches could be used to remove all intra orbital lesions apart from those located in the infero medial part of the orbit.

Approche épidurale temporopolaire transcaverneuse transpétreuse. Technique chirurgicale et indications

Background and purpose Several selective approaches have been recommended for access to the petroclival region (PCR). However, locoregional extension of the tumor may necessitate more extensive procedures. Dissections from injected specimens allowed us to describe the different osteodural triangles that are exposed to provide an extensive access to the PCR.

Anatomic study of the deep plantar artery: potential by-pass receptor site

The deep plantar artery is the main anastomosis between the dorsal and plantar arterial systems of the foot; with no change of calibre it unites the dorsalis pedis artery to the deep plantar arch, the second segment of the lateral plantar artery, passing into the first intermetatarsal space. Our anatomic study of 20 dissections of the deep plantar artery allowed us to verify the near-constancy of its descriptive anatomy and relationships. The deep plantar artery, when present, only found in 16 of our 20 cases, is totally linked to the dorsalis pedis artery. Its easy accessibility via the dorsal route, its medium calibre and the absence of collateral branches make this artery a possible anatomic site for the performance of a distal bypass, the last option before an amputation of the foot becomes necessary, although such a case remains exceptional.

Technique chirurgicaleApproche épidurale temporopolaire transcaverneuse transpétreuse. Technique chirurgicale et indicationsTemporopolar epidural transcavernous transpetrous approach. Technique and indications

Background and purpose Several selective approaches have been recommended for access to the petroclival region (PCR). However, locoregional extension of the tumor may necessitate more extensive procedures. Dissections from injected specimens allowed us to describe the different osteodural triangles that are exposed to provide an extensive access to the PCR.

Surgical anatomy of the jugular foramen

The jugular foramen (JF) is a canal that makes communication between the posterior cranial fossa and the upper neck for one third of the cranial nerves and for the main venous channel of the brain. From a lateral view, the JF is protected by multiple layers of muscles and by the outer surface of the petrous bone. Surgical exposure of the JF is usually justified by the removal of benign tumors that grow in this region. In the first part of the present study we describe the surgical anatomy of the JF Then, we detail the relevant points of a stepwise surgical progression of three lateral skull base approaches with a gradual level of exposure and invasiveness. The infralabyrinthine transsigmoid transjugular-high cervical approach is a conservative procedure that associates a retrolabyrinthine approach to a lateral dissection of the upper neck, exposing the sinojugular axis without mobilization of the facial nerve. In the second step, the external auditory canal is transsected and the intrapetrous facial nerve is mobilized, giving more exposure of the carotid canal and middle ear cavity. In the third step, a total petrosectomy is achieved with sacrifice of the cochlea, giving access to the petrous apex and to the whole course of the intrapetrous carotid artery. Using the same dissection of the soft tissues from a lateral trajectory, these three approaches bring solutions to the radical removal of distinct tumor extensions. While the first step preserves the facial nerve and intrapetrous neurootologic structures, the third one offers a wide but more aggressive exposure of the JF and related structures.