Attempts to remove the clot from the jugular bulb by curetting out the sinus from above are only referred to to be condemned. The surgeon who believes in this method hopes that all the infected portion of the clot will be swept out by the flow of blood. It is not, however, always possible to introduce a curette into the jugular fossa, and if the clot extends beyond this region it cannot be curetted away completely. The result of the operation does not depend so much on the skill of the surgeon as on whether the terminal portion of the clot be infected or not. Recovery is most likely to take place if a non-infective clot already extends beyond the region of the curette and so obliterates by natural means the lumen of the vein below the point reached by the surgeon. If, on the other hand, free hæmorrhage occurs as a result of the curetting, it means that the lumen of the vein has been restored, but there is no guarantee that all the clot has been completely removed. If any infective portion remains, a fatal result will almost certainly occur eventually as the result of pyæmia.
LIGATURE OF THE JUGULAR VEIN
Indications. Unfortunately, opinion is not unanimous with regard to this matter. The chief arguments raised against ligature of the jugular vein are: (1) That it favours extension of the thrombus along the veins communicating with it, especially along the inferior petrosal and condyloid veins, which enter the jugular bulb. (2) That it in no way prevents the spread of infection along other paths, owing to the freedom with which its tributaries communicate with one another. (3) As a result of obstruction in the circulation, acute inflammation of the cerebellum may take place.
Since the jugular vein should only be ligatured if the symptoms point to the onset of a general infection of the circulation and if it be found impossible at the time of operation to obliterate the sinus below the infected thrombus, and since this vein is the chief route by which this infection takes place, it seems a matter of common sense that it should be ligatured. At the same time, as many as possible of its tributaries above the point of ligature should also be ligatured well beyond the point at which they may be thrombosed.
Although extension of the infection may take place along other veins after ligature of the jugular vein, it is impossible to say whether the result is post or propter hoc. Against ligature, statistics have been quoted to show that in a series of cases in which the jugular vein has not been tied the percentage of recoveries is just as high as in those in which it had been ligatured. This argument is not quite sound, because there is no doubt that in the cases in which ligature of the jugular vein is justified the chances of recovery, owing to the extension of the thrombus downwards, must be less than in the less serious cases in which it is admittedly unnecessary to tie the vein. It is also impossible to say how many cases would otherwise have ended fatally if ligature had not been performed.
In the majority of cases the vein is ligatured after exploration of the lateral sinus. In a few cases, however, the symptoms warrant it being performed as a primary step of the operation, even before the mastoid process has been opened.
After exposure of the lateral sinus. (i) If the clot extends so low down that it is impossible to obliterate the lumen of the sinus below its lower limit.
(ii) If there be thrombosis of the bulb of the jugular vein. This condition is sometimes difficult to diagnose. There may be no symptoms excepting, perhaps, rigors occurring during the course of chronic middle-ear suppuration, as even the lower portion of the sinus may be quite normal in appearance owing to the clot being limited entirely to the jugular bulb. The probability of the diagnosis being correct is strengthened by the presence of granulations or carious bone on the floor of the tympanic cavity. It is better to risk tying a normal vein than to fail to tie one already infected.
(iii) If the sinus was obliterated above the jugular bulb at the primary operation and rigors occur subsequently, showing that the sinus is infected still lower down.
Before exposure of the lateral sinus. (i) If there be thrombosis of the jugular vein. In addition to the ordinary signs of lateral sinus thrombosis, there may also be infiltration of the tissues, or tenderness along the anterior border of the sterno-mastoid muscle. The prevalent idea that a thrombosed jugular vein can be felt on palpation as a hard cord extending down the neck is erroneous. If anything be felt it is probably some enlarged cervical glands lying along the line of the vein. In any case it is bad practice to palpate the internal jugular, as by doing so there is considerable risk of dislodging particles of the septic clot.