ANGIOGRAPHIC FEATURES OF THE PERICALLOSAL CISTERN

The arteries of the corpus callosum: a microsurgical anatomic study

OBJECTIVE

The corpus callosum is the major commissural pathway connecting the hemispheres of the human brain. It is particularly important, because various tumors and vascular lesions can be located in and around the corpus callosum, and it is a route through which pass several surgical approaches. Performing accurate surgery in this region and avoiding damage to normal structures require that the neurosurgeon have adequate knowledge of the anatomy of the intricate blood supply to this area.

METHODS

In 20 cadaver brains, the arteries of the corpus callosum were examined under the operating microscope, with particular attention to the origin, course, anastomoses, number, and caliber of the arteries.

RESULTS

In all specimens, the pericallosal and posterior pericallosal arteries were found to be the main sources of blood supply to the corpus callosum. In 80% of the specimens, the anterior communicating artery gave rise to either a subcallosal artery or a median callosal artery, each of which made a substantial contribution to the blood supply of the corpus callosum. A detailed examination of the anatomic features of all the main arteries of supply revealed anastomoses within the callosal sulcus that formed the pericallosal pial plexus. This network supplied the corpus callosum, the radiation of the corpus callosum, and the cingulate gyrus.

CONCLUSION

Familiarity with the details of the vascularity of the corpus callosum is crucial when performing surgery in this region. The additional, significant data described expands the knowledge of this anatomy, which can enhance the surgeon's ability to accomplish a more accurate and successful exploration.

Lesions of the corpus callosum in hydrocephalic patients with ventricular drainage--a CT-study

Patients with ventricular drainage may develop lesions of the corpus callosum. In order to study frequency, pathogenesis and clinical relevance of callosal lesions, 301 routine CT investigations of 79 patients with ventricular drainage were reviewed. Hypodense lesions in the anterior part of the corpus callosum were observed in 7 patients with longstanding hydrocephalus of variable origin, in 2 cases the corpus callosum was slightly swollen. All 7 patients showed signs of forced ventricular drainage. The callosal alterations were clinically inapparent and potentially reversible. Knowledge of these lesions is important to avoid misinterpretation.

The venous vascularization of the corpus callosum in man

The vascularization of the corpus callosum in Man is studied in 20 brains. Their vascular system is injected with Indian ink and gelatin. The corpus callosum is drained by callosal veins and callosocingulate veins towards the deep venous system of the brain. Most of these veins run downwards and join together at the central level of the corpus callosum. They then form the subependymal veins, which form the septal veins and the medial atrial vein. All these vessels are tributaries of the internal cerebral veins.

Microsurgery of tumours of the frontal white matter

Seventy eight microsurgical extirpations of tumours located in the frontal white matter led to adjustment of the normal anatomy of the frontal brain according to microsurgical requirements, and also to relation with modern diagnostic procedures, especially computerized tomography (CT-scanning). The advantages of microsurgical treatment have been demonstrated. Thus, only exact comprehension of topographical anatomy allows a methodical, careful, and radical procedure. As vessels were commonly saved, postoperative courses were relatively benign because of less tendency to oedema. Out of 78 patients, 3 died while in hospital, and two recurrences were observed in the following 23 months. Postoperatively 51 patients improved, 18 stayed unchanged neurologically, and 9 patients deteriorated permanently. The usual microsurgical instruments were employed. Vascular problems were dealt with by the routine techniques used at our hospital.

[Contribution to the diagnosis of cortical atrophy: evaluation of computer tomograms and angiograms of patients over 70 years old (author's transl)]

To find evidence of cortical atrophy, 112 computer tomograms and 40 angiograms of patients above the age of 70 were evaluated. In the CT the width of the interhemispheric and of the sylvian fissure, in the angiograms the distance between the vessels extending into the interhemispheric fissure (anteroposterior view) and the distance between the cortical branches and the inner table (lateral view) were measured. The same measurements were performed in 100 normal computer tomograms and in 100 normal angiograms of patients between 20 and 40 years old. Statistically significant differences could be ascertained between the mean values for the patients over 70 and those for the younger ones, indicating that age-induced cerebral atrophy can be neuroradiologically demonstrated. The radiologic findings, however, do not necessarily correspond to the grade of intellectual impairment in the elderly. Neuropathologic and molecular biological research could bring us closer to the solution of this correlative problem.