Severance

The premise of Apple TV’s award-winning series Severance is straight-forward: an individual agrees to a neurosurgical procedure that segregates their work life from their home life. Afterwards, they can bring no memories of their work back home, and no memories of home are accessible at work. It is proposed that this construct will improve work/life balance but, of course, a more sinister side reveals itself.

I can think of days at work I would rather forget and others I hope to always remember. Sometimes operating is so immersive and all-consuming that it generates a partially severed state from the outside world. Those musings aside, this TV premise is, of course, fantastical and the surgical procedure to enable it is dubious to say the least. 

The neurosurgical procedure during which the severance chip is implanted is depicted with the patient awake and positioned in a Mayfield head clamp. So far, so good – awake neurosurgery harks back to ancient times. In ancient times, however, the patient was presumably not wearing the mascara and eyeliner we see here.

Most troubling is that the surgeon (wearing a completely unnecessary set of surgical loupes) appears to approach chip implantation via a posterior midline burr hole. Performing said burr hole with the DIY drill bit shown is ill-advised. Contemporary cranial perforators have a clutch mechanism that disengages the drill just as the inner table of the skull is opened to prevent plunging into the brain. No such safety methods are needed in Severance. The operator definitely plunges just a little but seems none too flustered. Maybe that’s because there’s remarkably little blood.

All of these points are minor, however, when it comes to the method and trajectory of chip implantation. Stereotactic apparatus defines the brain as a three-dimensional system of Cartesian coordinates, allowing reasonably accurate anatomical targeting. Frame-based and frame-less stereotactic techniques are old hat in neurosurgery, the former dating back to 1908. But for TV, we instead revert to a single-plane image intensifier and a freehand biopsy needle. 

As for needle trajectory, it is hard to be sure exactly what happens. It appears that the biopsy needle would have passed first through the posterior third of the superior sagittal sinus (at this point a torrentially high-flow venous outflow channel), then some brain parenchyma, then several more critically important venous structures (including the great vein of Galen), and the clip itself appears to be deployed somewhere within the midbrain.

As a consequence of these transgressions, the patient would certainly have been severed – and headlining the monthly M&M meeting. But no, she is intact post-op, with conjugate eye movements and not a smudge to her make-up.