The usefulness of 3D MR angiography in surgery for ruptured cerebral aneurysms

BACKGROUND

We have used magnetic resonance angiography (MRA) in screening for unruptured cerebral aneurysms since 1993. The development of high-resolution magnetic resonance (MR) imaging has led to a remarkable improvement in image quality. Three-dimensional (3D) MRA can be used for surgical simulation. Here, we report on the usefulness of and problems associated with 3D MRA for the surgery of ruptured cerebral aneurysms.

METHODS

Between June 1998 and June 2000, 106 patients with SAH diagnosed by 3D MRA underwent surgery. We compared 3D MRA images with operative findings and investigated the usefulness of this assessment tool.

RESULTS

In 48 of 106 cases (45.3%), we were able to perform surgery based on 3D MRA alone. By using the 3D images, we could easily detect the relative location of the aneurysm, its neck and the surrounding arteries. The remaining cases required further examinations because of uncertainty of diagnosis or insufficient information.

CONCLUSION

3D MRA is a safe and useful procedure for the diagnosis and surgery of ruptured cerebral aneurysms. However, in approximately half of all cases, 3D computed tomographic angiography (CTA) or digital subtraction angiography (DSA) is required in addition for the planning of surgery. It is important to use 3D MRA for surgery only after taking sufficient consideration of certain limitations peculiar to MRA.

Aneurysms arising from the cortical segment of the superior cerebellar artery--two case reports

Two unusual cases of partially thrombosed or fusiform type aneurysm on the cortical segment of the superior cerebellar artery (SCA) with subarachnoid hemorrhage are described. A 71-year-old female had a partially thrombosed, multi-lobular aneurysm located at the marginal branch of the SCA. This aneurysm was successfully clipped and wrapped via a subtemporal transtentorial approach in the acute stage. A 52-year-old female had an atherosclerotic fusiform aneurysm located at the distal portion of the hemispheric branch of the SCA. This aneurysm was successfully trapped using an infratentorial supracerebellar approach in the acute stage. Both patients were discharged without neurological deficits. The subtemporal transtentorial or lateral suboccipital approach for the proximal cortical segment, and the infratentorial supracerebellar approach for the distal cortical segment of the SCA are recommended for surgical treatment of these aneurysms.

Cardiovascular function before and after iron therapy by echocardiography in patients with iron deficiency anemia

BACKGROUND

The aim of the study was to estimate the left ventricular contractility using the ratio of left ventricular end-systolic wall stress to left ventricular end-systolic volume index in patients with iron deficiency anemia, for which there are no previous reports.

METHODS

Cardiovascular functions were evaluated using echocardiography and pulsed Doppler echocardiography in 30 children aged 3-14 years (hemoglobin 4.9-8.5 g/dL), before, during and after iron therapy. We also studied 38 healthy children as a control group.

RESULTS

The left ventricular preload was significantly higher and the left ventricular afterload was lower in the patients with anemia before iron therapy. The ratio of left ventricular end-systolic wall stress to left ventricular volume, an index of systolic function that is independent of preload and afterload, was significantly lower in the patients with anemia before iron therapy (before iron therapy 2.13 +/- 0.44, after therapy 3.52 +/- 0.76, healthy controls 3.42 +/- 0.70). Left ventricular early diastolic filling was significantly higher in the patients with anemia before iron therapy. The cardiac index was also significantly higher before therapy because of the increases in preload, heart rate and early diastolic filling, as well as the decrease of afterload. There were no significant differences in the indices of cardiovascular function between anemic patients after iron therapy compared with control subjects.

CONCLUSIONS

The ratio of left ventricular end-systolic wall stress to the left ventricular volume index and the cardiac index suggested that a hemoglobin concentration < or = 6 g/dL was associated with left ventricular dysfunction and circulatory congestion.

[Surgery of acoustic neurinoma in a hemodialyzed patient]

Successful surgical treatment of acoustic neurinoma in a case of hemodialyzed patient is reported. A 42-year-old female patient, who had been treated by hemodialysis, was diagnosed as having a C-P angle tumor by CT scan. She was refered to our clinic on June 24, 1983. Laboratory examinations on admission showed severe anemia and renal dysfunction. Every possible treatment was done in order to improve the laboratory data preoperatively. Another big problem in this case of hemodialyzed patient was brain edema and bleeding tendency. In order to cope with brain edema, intravenous administration of glycerol and slow hemodialysis for three days were performed preoperatively. These treatments were thought to be effective to reduce bleeding tendency also. During operation, however, heavy swelling of the cerebellum forced us to resect one third of the hemisphere to remove the tumor totally. In addition to this, postoperative mild bleeding in the cavity after tumor resection, subcortical hemorrhage around the shunt tube and oozing from the wound were observed. The patient was discharged from the hospital four months after surgery without any neurological deficit. The way of recovery, however, was not uneventful, because the patient developed various kinds of postoperative complications as mentioned above. In the postoperative managements, we felt almost as if we were treading on thin ice. Neurosurgical management in hemodialyzed patients is not yet very common. We should improve the postoperative management by adding new experience with similar cases.

[An autopsy case of intracranial multiple meningiomas associated with extracranial multiple neurinomas]

An autopsy case of intracranial multiple meningiomas associated with extracranial multiple neurinomas was presented. A 55-year-old woman, who had received surgical treatment for right parasagittal meningioma 20 years ago, gradually showed the sign of increased intracranial pressure and disturbance of the lower cranial nerves. Brain CT scan demonstrated numerous intracranial tumors. At autopsy 124 intracranial meningiomas, and neurinomas in her left cervical and right axillar portion were found. Meningiomas showed the transitional and fibroblastic type, histopathologically, and axillary and cervical tumors were the Antoni A type neurinomas. It is suggested that this case had a tendency of heterogenous and multiple origination of tumors.

[Case of postoperative subdural tension pneumocephalus]

In this paper, a case with subdural tension pneumocephalus secondary to bifrontal craniotomy and VP shunt for ruptured Acom aneurysm is reported. In this patient, the mechanisms for entry of air into the subdural space and producing mass effect (Tension pneumocephalus) seem to be one way valve mechanism and negative pressure due to excess of CSF drainage owing to shunting system. Only 29 reported cases of tension pneumocephalus following surgery were found in an extensive review of the literature. We discussed about the clinical symptoms and signs, therapy, and especially about the mechanisms leading to this condition, and prevention for it.

[Direct surgical obliteration of a persistent trigeminal artery aneurysm]

A successful case of ruptured aneurysm of the persistent trigeminal artery (PTA) treated with direct operation is reported. Only 14 cases out of ever-reported 400 cases with persistent trigeminal artery have aneurysms developing from PTA itself or its junction. These aneurysms originate most frequently from the trunk portion of the PTA. In our case, aneurysms are found at the rt. internal carotid-PTA junction and the rt. IC-PC junction. Six out of 14 are associated with another intracranial aneurysms, indicating high multiplicity. Of 14 cases, only 2 including our case are treated by direct surgery. Since the internal carotid-PTA junction aneurysm is located in the cavernous sinus, special consideration is needed during the operation. Surgical keypoints in opening the cavernous sinus under normothermia and getting the landmark for orientation are described.