Zusammenfassung
Bei 13 Patienten mit totalem Hirninfarkt konnte der zerebrale Kreislaufstillstand
atraumatisch mit der Radio-Isotopen-Angiographie (RIA) unter Verwendung von 99m Technetium-Pertechnetat und der Multi-kristall-Kamera innerhalb von 3—4 Minuten sicher
nachgewiesen werden.
Aufgrund der bisherigen Befunde, die ausnahmslos mit der angeschlossenen bilateralen
Karotiskontrast-angiographie, in drei Fällen auch mit der 133 Xe-Gamma-Clearance-Methode bestätigt werden konnten, sind wir der Auffassung, daß
die RIA der konventionellen Röntgen-Kontrast-Angiographie bezüglich der Hirntodesdiagnose
zumindest gleichwertig, hinsichtlich eines zu sichernden Transplantationserfolges
aber überlegen ist, da die schonend und schnell durchzuführende RIA zu keiner weiteren
ischämischen Schädigung des zu transplantierenden Organes führt.
Bei weiteren 12 Patienten mit erheblich reduzierter zerebraler Durchblutung (schweres
Schädel-Hirn-Trauma, apallisches Syndrom) wurde demonstriert, daß auch diese Zustände
von der RIA erfaßt und von dem des totalen Hirninfarktes eindeutig unterschieden werden
können.
In the field of organ transplantation and in brain death patients where intensive-care
measures may seem superfluous, the demonstration of cessation of cerebral blood flow
by X-ray angiography is generally agreed to be the diagnostic procedure of choice
to prove irreversible loss of cerebral function. There are, however, certain drawbacks
involved in X-ray angiography. Arterial puncture is necessary. Furthermore, the procedure
can be time-consuming, thus making the continuation of adequate intensive-care measures
more difficult. At the same time the circulatory condition may worsen causing hypoxic
damage to the organ to be transplanted.
In the present paper, the authors report on 13 patients with clinical signs of brain
death where cessation of cerebral blood flow was demonstrated atraumatically by intravenous
radioisotope angiography (RIA) using a multicrystal gammacamera (Baird Atomic) and
the bolus-injection technique with 99m Tc-pertechnetate.
Nine patients had severe brain injuries, 2 patients had brain tumours, 1 patient had
encephalitis and 1 patient had suffered prepartal thrombosis of the sinus sagittalis.
In all patients EEG recordings were isoelectric. At the time when the RIA was performed
systolic blood pressure had decreased to 62—85 mmHg ([math] mmHg), while body temperature
had declined to 31—36,5° C ([math]).
According to the present results, which were all confirmed by subsequent bilateral
carotid X-ray angiography, total brain infarction is unequivocal when the following
criteria are satisfied using RIA: 1. when the radioisotope bolus flows along the common
carotid arteries but does not proceed any further than to the base of the skull or
around the scalp structures, 2. when, at the moment when the radioactivity outlines
the scalp structures, neither the intracranial arteries nor the capillary bed or the
venous sinuses are visible, 3. when the time-activity curves across the hemispheres
show simply a plateau of low count rate without the activity peak typical for cerebral
tracer circulation and 4. when the activity peak, typical for venous outflow, is missing
from the time-activity curves for the cervical areas.
In 12 patients with extremely reduced cerebral blood flow it was demonstrated that
the RIA findings were clearly different from those obtained at brain death Moreover,
not one of 438 other patients undergoing RIA exhibited the same features which were
associated with brain death.
The authors conclude that RIA involves the same degree of safety as X-ray angiography
in the diagnosis of total brain infarction but is superior to the latter when the
diagnostic procedure has to be performed quickly, thus reducing the risk of any further
damage to a prospective donor organ.
