Ernesto Coscarella

An alternative extradural exposure to the anterior clinoid process: the superior orbital fissure as a surgical corridor.

OBJECTIVEDolenc has pioneered the extradural approach to the anterior clinoid process (ACP) in approaching the cavernous sinus, clinoidal space, and orbital apex. A key step is the division of the frontotemporal dural fold (FTDF). Less experienced surgeons may not be as versatile in their three-dimensional understanding of the superior orbital fissure and thus may risk injury to its contents. Through our cadaveric and subsequent clinical experience, we have devised a modification of the approach that permits safer handling of the contents of the superior orbital fissure. METHODSIn five consecutive injected cadaveric heads (10 sides), we performed on one side a traditional extradural exposure of the ACP. On the other side, we performed our alternative dissection. Instead of exposing the ACP from medial to lateral and dividing the frontotemporal dural fold along the assumed path of safety, we followed the edge of the lesser wing from lateral to medial, uncovered the superior orbital fissure, and peeled the outer layer of the cavernous sinus medial to the foramen rotundum along the greater wing, thus uncovering the inferolateral surface of the ACP. This allowed dural division under full visualization. RESULTSThe alternative method proved easier and more reliable in every case. We applied this technical modification in seven patients with no complications. Specifically, there was no injury to the oculomotor, lacrimal, frontal, or trigeminal nerves or branches. We present detailed anatomic expositions of the injected specimens. CONCLUSIONThis technical modification of the extradural approach of Dolenc is a simple, safe, and valuable adjunct to the exposure of the ACP. We recommend its use particularly by relatively inexperienced surgeons.

Minimally invasive cervical expansile laminoplasty: an initial cadaveric study.

OBJECTIVEExpansile laminoplasty has been successfully used to treat cervical myelopathy attributable to canal stenosis. However, detachment of the posterior cervical muscles is thought to contribute to postoperative axial neck pain and kyphosis. Minimizing the amount of muscular dissection might reduce the likelihood of these sequelae. METHODSSix human cadaveric spines were used to assess the feasibility of a minimally invasive laminoplasty technique. A 22-mm tubular dilator port was used to access the lamina-facet junctions from C2 to C7, through bilateral stab incisions at C4–C5 and C5–C6. Troughs at the lamina-facet junctions were drilled bilaterally, and the contiguous laminae were lifted en bloc from one side. Ten-millimeter rib allograft spacers were inserted to maintain a gap on the open side. RESULTSExposure of six cervical levels was easily accomplished with two small incisions on each side. Drilling was achieved without dural violations. The midsagittal spinal canal diameter was increased by a mean of 38% and the spinal canal area was increased by an average of 43% at the level of C5. CONCLUSIONA minimally invasive approach for cervical laminoplasty could be performed in human cadavers. The measured increases in spinal canal space approximated those demonstrated to be associated with stabilization or improvement of neurological status.

Aneurysm of the anterior inferior cerebellar artery-posterior inferior cerebellar artery variant: Case report with anatomical description in the cadaver

OBJECTIVE AND IMPORTANCE: The authors report a very rare case of an aneurysm at the distal segment of the anterior inferior cerebellar artery-posterior inferior cerebellar artery (AICA-PICA) variant along with a description of the surgical anatomy of this variation in a cadaveric specimen. CLINICAL PRESENTATION: A 44-year-old woman experienced the sudden onset of severe headache and vomiting. Computed tomographic scanning revealed subarachnoid and intraventricular hemorrhage. Cerebral angiography demonstrated a saccular aneurysm arising from the tonsillomedullary segment of the right PICA and a second aneurysm arising from the cortical segment of the common trunk of an AICA-PICA variation. INTERVENTION: Via bilateral suboccipital craniotomy, both aneurysms were clipped. CONCLUSION: Only two cases of aneurysms arising from an AICA-PICA variation have been reported in the literature and no detailed description of the surgical anatomy of this variation has been carried out in previous publications. To our knowledge, the present report is the first description of a clinical case along with a detailed surgical anatomic study in a cadaver.

Surgical management of middle cerebral artery aneurysms: Surgical anatomy, approaches, and pitfalls

Aneurysms of the middle cerebral artery pose a significant challenge to neurosurgeons. The authors describe surgical techniques, clinical features, and different approaches to treat these aneurysms in light of surgical anatomy, lessons learned from complications, and personal experience.