Microsurgical Anatomy of the Lateral Posterior Choroidal Artery and Its Thalamic Branches.

BACKGROUND: Only a few articles have been published about the lateral posterior choroidal artery (LPChA), and yet none of them contains data regarding the thalamic branches. METHODS: The LPChA and its twigs of the 26 cerebral hemispheres were injected with a mixture of a 10% Indian ink and gelatin. Following fixation in a 10% formaldehyde solution, the vessels were micro dissected under the stereoscopic microscope. In addition, serial cerebral angiograms of the 168 patients were examined. RESULTS: The LPChA, which was commonly singular or double and averaged 0.68 mm in diameter, most often originated from the P2 and P3 segments (76%) of the posterior cerebral artery (PCA). It always gave off the choroidal, pulvinar and typical thalamic branches, occasionally the parahippocampal (4%), hippocampal (8%), peduncular (8%), tegmental (12%), pretectal (4%), lateral geniculate (40%) and medial geniculate twigs (16%), and the forniceal, subependymal (100%), stria terminalis (32%), and caudate twigs (28%). The pulvinar and thalamic branches averaged almost 4 in number and 0.27 mm in diameter. They most often supplied the pulvinar nuclei, and occasionally portions of the mediodorsal, lateral dorsal, lateral posterior, ventral lateral, and the ventral posterior thalamic nuclei. Among the 168 serial cerebral angiograms, one presented the arteriovenous malformation of the LPChA, but no one showed an aneurysm. CONCLUSIONS: This is the first description of the LPChA thalamic branches to date. Their microanatomic features are important for understanding the neurologic symptoms following vessels occlusion, for precise radiologic diagnoses, and for safe neurosurgical and endovascular interventions.

Arterial supply and morphological characteristics of sympathetic neurons in the human superior cervical ganglion.

The aim of this study was the micromorphological analysis of the distribution of microvessels, mast cells and ganglionic neurons in two parts, proximal and distal of the human superior cervical sympathetic ganglions (SCSGs). Statistical analyses were applied to detect the possible metric regional differences in their densities. Five injected human SCSGs with colored India ink and gelatin were microdissected and examined. Second group of five human SCSGs was prepared and serially sliced for CD34 and mast cell tryptase immunostaining. The microscopic fields of two parts of the SCSGs were analyzed for the following quantifications: microvessel density (MVD), mast cell density (MCD), and ganglionic cell count and measurements. The mean number of CD34-positive microvessels in microscopic fields, the MVD, had a value of 83 for the upper parts, and 82.7 for the lower parts of SCSGs. The mean number of tryptase-positive mast cells in microscopic fields, the MCD, was 4.5 in the proximal parts, and 4.7 in the distal parts of SCSGs. The mean number of ganglionic neurons in microscopic fields was 19.5 in the proximal parts, and 19.8 in the distal parts of SCSGs. The density of CD34-positive microvessels, the density of tryptase-positive mast cells, and the density, mean diameters and mean areas of ganglionic neurons were not significantly different in two observed parts, upper and lower of the SCSGs. In conclusion, the distributions of microvessels, mast cells, and neurons in two parts of the SCSGs were uniform with no specific micromorphological variations, there is a homogenous vascular and cellular pattern within the SCSGs.

Persistent median artery and communicating branch related to the superficial palmar arch.

Microvascular surgery, plastic and reconstructive hand surgery, and coronary artery bypass surgery call for a microanatomical study of the branching pattern of the superficial palmar arch (SPA). For the anatomical analysis, we used a group of 20 dissected human hands injected with 4% formaldehyde solution and a 10% mixture of melted gelatin and India ink. The morphometric study was performed on 40 human hands of adult persons injected with methyl-methacrylate fluid into the ulnar and radial arteries simultaneously and afterwards corroded in 40% KOH solution for the preparation of corrosion cast specimens. The mean diameter of the SPA, between the second and third common palmar digital arteries, was 1.86 ± 0.08 mm. We identified the persistent median artery (PMA) in 5% of hands. We distinguished the three main groups of the SPAs according to variations in morphology and branching of the arch: Type 1, the long SPA; Type 2, the middle length SPA; and Type 3, the short SPA found in 27.5% of specimens. The communicating branch (CB), a vessel interconnecting the SPA to the closest branch of the radial artery, is classified into two different morphological groups. The third type of incomplete short arterial arch is the most important of the three groups of SPAs. That short SPA is potentially inadequate for restoring circulation after occlusion or radial artery harvesting for coronary artery bypass.

Medullary branches of the vertebral artery: microsurgical anatomy and clinical significance.

BACKGROUND: Since the medullary arteries are of a great neurologic and neurosurgical significance, the aim was to perform a detailed microanatomic study of these vessels, as well as of the medullary infarctions in a group of patients. METHODS: The arteries of 26 halves of the brain stem were injected with India ink and gelatin, microdissected and measured with an ocular micrometer. Neurologic and magnetic resonance imaging (MRI) examinations were performed in 11 patients. RESULTS: The perforating medullary arteries, averaging 6.7 in number and 0.26 mm in diameter, most often originated from the anterior spinal artery (ASA), and rarely from the vertebral (VA) (38.5%) and the basilar artery (BA) (11.6%). They supplied the medial medullary region. The anterolateral arteries, 4.8 in number and 0.2 mm in size, most often arose from the ASA and PerfAs, and nourished the anterolateral region. The lateral arteries, 2.2 in number and 0.31 mm in diameter, usually originated from the VA and the posterior inferior cerebellar artery (PICA). They supplied the lateral medullary region. The dorsal arteries, which mainly arose from the PICA and the posterior spinal artery (PSA), nourished the dorsal region, including the roof of the 4th ventricle. The anastomotic channels, averaging 0.3 mm in size, were noted in 42.3%. Among the medullary infarctions, the lateral ones were most frequently present (72.8%). CONCLUSION: The obtained anatomic data, which can explain the medullary infarctions symptomatology, are also important in order to avoid damage to the medullary arteries during neurosurgical and neuroradiologic interventions.

Spondylocostal Dysostosis Associated with Split Spinal Cord and Other Malformations.

Spondylocostal dysostosis is a very rare combination of complex vertebra and rib malformations, accompanied occasionally by other disorders. A 3-year-old girl presented kyphoscoliosis, foot deformities, gate disturbance, and urinary incontinence. The CT and MRI examination revealed kyphosis and scoliosis with a double curve, some absent, broadened, bifurcating and fused ribs, hemivertebrae, butterfly and cleft vertebrae in thoracic and lumbar region, sporadic cleft or absent vertebral arches or pedicles, and hypoplastic sacrum with a cleft of the S2 vertebra. Spina bifida occulta extended from T10 to T11, and from L3 to the end of the sacrum. Two hemicords, separated by a bony septum and surrounded by their own dural tubes (type I), were present from the level of T9 to the conus medullaris. Filum terminale was thick and duplicated. Syringomyelia was present in the thoracic cord from T5 to T8. Finally, a small meningocele was seen at the T10-T11 level, and a subcutaneous lipoma in the thoracolumbar region. To our knowledge, such a combination of vertebra, rib, and cord malformations, including the mentioned additional disorders, has never been reported.