E. Havet

Microsurgical anatomy of distal medial striate artery (recurrent artery of Heubner)

IntroductionIn literature, many controversies exist about courses and terminology of the distal medial striate artery (DMSA) or recurrent artery first described by Heubner near 1872. The purpose of this study was to define the accurate anatomy of this artery, to help the practitioners during surgery of the anterior cerebral–anterior communicating arteries (ACA–ACoA) complex.Materials and methods20 cranial bases were examined using magnification of the surgical microscope. One half for which the internal carotid arteries and internal jugular veins were dissected, cannulated and perfused with colored silicon on fresh cadavers; the other half only with arterial injection of formalin-fixed normal adult human brains.ResultsThe artery arose principally from A2 segment (58%), always less than 5xa0mm up to downstream from ACA to ACoA junction. In 59.5% it had a recurrent course anterior to A1 segment. It terminated in one to three stems which entered the medial part of the anterior perforated substance. The DMSA was present as a single vessel in 95% of cases. Its main outer diameter was 0.7xa0mm and the length had an average of 24xa0mm.ConclusionIatrogenic damage or occlusion leads to a mediobasal striatum infarction with important neurological deficits such as brachiofacial hemiparesis and aphasia. This artery should be routinely identified during clipping of ACoA aneurysm. Special attention in this study was given to atypical posterior course or anatomic variations such as double DMSA on a same side.

Microsurgical Anatomy of the Anterior Commissure: Correlations With Diffusion Tensor Imaging Fiber Tracking and Clinical Relevance

BACKGROUND Detailed anatomy of the anterior commissure is unknown in the literature. OBJECTIVE To describe the anterior commissure with the use of a fiber dissection technique by focusing on the morphology (length and breadth of the 2 portions), the course, and the relations with neighboring fasciculi, particularly in the temporal stem. METHODS We dissected 8 previously frozen, formalin-fixed human brains under the operating microscope using the fiber dissection described by Klingler. Lateral, inferior, and medial approaches were made. RESULTS The anterior olfactive limb of the anterior commissure was sometimes absent during dissection. The cross-sectional 3-dimensional magnetic resonance rendering images showed that fibers of the anterior commissure curved laterally within the basal forebrain. The tip of the temporal limb of the anterior commissure was intermingled with other fasciculi in various directions to form a dense 3-dimensional network. CONCLUSION Functional anatomy and comparative anatomy are described. The anterior commissure can be involved in various pathologies such as diffuse axonal injury, schizophrenia, and cerebral tumoral dissemination.

An unusual superolateral origin of ophthalmic artery: an anatomic case report.

Background and importanceIf ophthalmic artery’s (OphA) origin anomalies are frequent, the superolateral origin of the OphA was rarely described.Clinical presentationDuring an aneurysmal surgery, a superolateral origin of the left OphA was found. This variation was associated with a sylvian aneurysm. The anatomical, embryological features, the neurosurgical implications of this origin such as treatment of carotid-ophthalmic aneurysm or intra arterial retinoblastoma chemotherapy are discussed.ConclusionTo the best of our knowledge, this is a very rare operative case of both superolateral origin and initial course of OphA.

Microsurgical anatomy of branches of musculocutaneous nerve: clinical relevance for spastic elbow surgery.

PurposeThe neurotomy of musculocutaneous nerve is a treatment for patients who suffer from spastic elbow flexion when medical and reeducative treatments have failed. It consists in sectioning motor branches of musculocutaneous nerve which are destined to the biceps brachii and brachialis muscles, both being the main elbow flexor muscles. The aim of this study was to analyse the distance, where each motor branch arises from the musculocutaneous nerve to both biceps brachii and brachialis muscles, to establish precisely the localisation and length of the necessary incision to reach its branches for surgery.Materials and methodsEighteen musculocutaneous nerves from ten cadavers were dissected. None of them reported with a previous pathology. The cadavers were laid on the back with 30–35° of abduction, a complete extension, and supination of the upper limb.ResultsThe localization of motor branches was to be found in the middle third of the upper arm, with an average from the base of the humeral major tubercle of 11.46, 12.40, and 12.87xa0cm for the biceps brachii and 16.36, 19.10, and 16.88xa0cm for the brachialis muscle.ConclusionThe incision needed to reach the motor branches of the musculocutaneous nerve should be localised between 10 and 20xa0cm from the major humeral tubercle and may be shorter than usual.

Microsurgical anatomy of the medial tentorial artery of Bernasconi–Cassinari

ObjectiveIn the current literature, there is a lack of detailed map of the origin, course and relationships of the medial tentorial artery (MTA) of Bernasconi–Cassinari often implicated in various diseases such as dural arteriovenous fistulas of the cranial base, stenotic lesions of the ICA, saccular infraclinoid intracavernous aneurysms and tentorial meningiomas.MethodsUsing a colored silicone mix preparation, ten cranial bases were examined using ×3 to ×40 magnification of the surgical microscope.ResultsThe MTA arose as a single branch in 95% of cases from the MHT at the level of the C4 segment of the internal carotid artery. The average length of the MTA was 21.7xa0mm (range 20.0–23.4xa0mm). The average diameter of the MTA was 0.53xa0mm (range 0.49–0.60xa0mm).The MTA passed just below the lower dural ring detached from the lower margin of the anterior clinoid process. During its course, the MTA drop over the intracavernous segment of the abducens nerve twisted at its exit from the Dorello’s canal and overlay the trochlear into the thickness of the free margin of the tentorium cerebelli. Vascular relationships of the MTA were venous trabeculation of the cavernous sinus, basilar plexus and branches of the inferolateral trunk. The MTA sent two terminal branches: one medial rectilinear, which pursued the initial dorsal course, and the other shorter with a lateral course, which disappeared into the lateral wall of the cavernous sinus. The medial branch of the MTA curved laterally, ramifying within the free edge of the tentorium cerebelli and anastomosing along the base of the dorsal part of the falx.ConclusionThe implications of these anatomic findings for surgery or endovascular procedure are reviewed and discussed.

Erratum to: Anatomical basis of the extended TDAP flap: study of its territories of vascularization and its volume

Introduction nThe concept of extended thoracodorsal artery perforator (TDAP) flap was described in 2015 for breast reconstruction. Our anatomical study aims to identify the territories vascularised by the thoracodorsal artery perforator via the deep muscular fascial network. The second goal was to define the volume of the extended TDAP flap.

Microsurgical anatomy of the Adamkiewicz artery-anterior spinal artery junction

PurposeThe aim of this study is to describe the anterior spinal artery–Adamkiewicz artery (ASA–AKA) junction and establish a classification allowing defining the neurological risk in either thoracoabdominal aorta aneurysm treatment and in anterior or transforaminal thoracolumbar spine surgery.MethodsFifteen spinal cords of fresh cadavers were dissected. Both lumbar arteries and ASA were injected with strongly diluted red-colored silicon.ResultsThe dural crossing of AKA was located on the left side in 86xa0% of cases, between T8 and T10 in 73.33xa0% of cases and L1–L2 in 26.67xa0% of cases. The average diameter of the ascending branch of AKA was 1.10xa0mm (range 0.8–1.9xa0mm), and its average length was 30.27xa0mm (range 12.3–60xa0mm). The AKA’s arch average diameter was 11.3xa0mm (range 9–20xa0mm) with an open downward angle average of 20.1° (range 11°–30°). The descending branch of AKA which was a continuation of ASA had an average diameter of 1.33xa0mm (range 0.8–1.86xa0mm). The ASA at the top of the arch had an average diameter of 0.74xa0mm (range 0.2–1.77xa0mm). According to these findings, we have proposed a new classification with two types of junctions. The type I and its variant correlated to high neurological risk were present in 93.33xa0% of cases. The type II, correlated to medium or low neurological risk, was present in 6.67xa0% of cases.ConclusionThese anatomical findings allow a planning of the neurological risk before thoracoabdominal aorta aneurysm or thoracolumbar anterior or transforaminal spine surgery.

Application de l’interférométrie à la chirurgie mammaire

But de l’etude la chirurgie plastique mammaire restait du domaine du subjectif ou chaque intervention etait dependante de l’habilete, de l’experience et de l’appreciation du chirurgien. En effet il n’existait pas jusqu’ici d’instrument de mesure objectif de cette region anatomique permettant de planifier cette chirurgie. Dans ce but, nous avons voulu valider l’utilisation de l’acquisition surfacique 3D par une technique de projection de lumiere structuree (Inspeck ® ) en chirurgie du sein. Materiel et methodes nous avons teste les instruments de mesure (distance euclidienne, distance projetee sur surface et calcul de volume) du systeme acquisition 3D sur des distances et des protheses mammaires de volumes connues, experimentalement (ex vivo) et cliniquement (sur des modeles). Nous avons par ailleurs realise l’acquisition 3D de plus de 50 patientes. Resultats nous avons pu mettre en evidence les avantages du systeme Inspeck ® en terme de faisabilite, de faible contrainte, d’inocuite, de reproductibilite inter, intra observateur et au changement, comparativement aux autres techniques d’acquisitions 3D. Des coefficients de variation entre mesure classique et mesure 3D tous inferieurs a 5 % objective l’adaptation de cette technologie a la biometrie de la region mammaire. Conclusions les perspectives de la numerisation 3D par projection de lumiere structuree sont nombreuses. Cette etude realise l’evaluation indispensable avant toute utilisation d’un nouvel outil de mesure en clinique. Elle autorise une application clinique immediate pour le chirurgien. A terme, elle permettra d’obtenir une certaine objectivite dans la chirurgie.

Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report

In this anatomy report, we describe the first case of abducens nerve duplication limited to the sphenopetroclival venous gulf and the cavernous sinus. The objective point of division of the two duplicated roots was localized at the gulfar face of the dural porus, just distal to the unique cisternal trunk of the abducens nerve, as it pierced the petroclival dural mater. In the gulfar segment, both roots traveled through a variant of Dorello’s canal called the “petrosphenoidal canal” and remained separated through the posterior half of the cavernous sinus. Both roots finally fused in the anterior half of the cavernous sinus to innervate the lateral rectus muscle as a single trunk. Although many variants of the abducens nerve have been reported over the recent decades, this anatomic variation has never been previously described and enriches the continuum of abducens nerve variations reported in the literature data. Awareness of this variation is crucial for neurosurgeons, especially during clival or petrosal surgical approaches used for resection of skull base chordomas.

Cortical and subcortical functional neuroanatomy for low-grade glioma surgery

Knowledge of the encephalon anatomy is crucial for neurosurgical practice, especially the main cortical functional structures and their connections. General organisation of the encephalon is presented with frontal, parietal, occipital, temporal, limbic and insular lobes and their Brodmann correspondence. Secondly, subcortical anatomy will be presented with main white matter fasciculi in three separated categories: association, commissural and projection fibers. Main association fibers are inferior occipitofrontal fasciculus, superior longitudinal fasciculus, arcuate fasciculus, inferior longitudinal fasciculus, uncinate fasciculus, and cingulum. Commissural fibers include anterior commissure, corpus callosum and fornix. Projection fibers are internal capsule and optic radiations.