Optometrist shares perspective on neurosurgical procedure
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Working as an optometrist in a major hospital system in the Boston area has its perks.
Recently, I was fortunate enough to be able to sit in on a neurosurgery for one of my patients. The experience was immensely illuminating and left quite an impression — a unique insight into a world of health care many of us will never get to witness. Here, I share it with you.
The day began with neurosurgery rounds, which started just after 7 a.m. The team saw two patients at the bedside who had recently underwent spinal surgery: One was a spinal fusion/laminectomy, and the other involved osteomyelitis. The team was interested to know how the patients’ prior night went, how they slept and what their level of pain was.
Then it was time to prepare for surgery. The case involved a white male in his 70s with a recurrent sphenoid wing meningioma. The patient had a history of prior craniotomy with tumor resection several years ago. CT revealed significant increase in tumor size over the past year (MRI was contraindicated due to a history of shrapnel injury). There was concern for superior orbital fissure involvement and possible compression on the optic nerve. Vision was declining, visual field defects were worsening, and the patient had intermittent diplopia due to multiple cranial nerve deficits. After discussing management options, surgery was chosen.
React and adapt
The operating room is sort of like a busy kitchen: Numerous personnel come and go, bringing supplies, calling for assistance, communicating with each other, swapping out to give each other breaks. When certain "ingredients" (ie surgical tools) weren't working for their intended purpose, others had to be used instead. These adjustments were constantly being made, with the surgeon reacting and adapting to changing circumstances and new information.
First, the surgical site was confirmed, marked and draped in a sterile fashion. Great care was taken throughout the entire procedure to ensure sterility. The patient’s hair was shaved to allow access to the cranium, and his head was tightly positioned using a three-point fixation device to eliminate any movement during surgery. An incision allowed the skin and temporalis muscle to be resected, creating a flap with access to the skull. Since the patient previously had a craniotomy, there were already cranial incisions present with screws and a burr site from the prior surgery. The surgeon noted that the dura was particularly difficult to remove due to scar tissue from prior surgery, which created tighter adhesion between the dura and the skull.
Once the skull flap was created, it was time to shift focus to the brain and begin the process of accessing the tumor. Neuro-navigation programs allowed for live-viewing of CT images before and during the surgery. The software identifies and maps several anatomical landmarks prior to beginning surgery. During surgery, the surgeon would periodically use the neuro-navigation software to ensure that different sections of the tumor were resected. This was particularly fascinating to watch, as you could really appreciate the juxtaposition of neuroimaging and live anatomy during the procedure.
The surgery was bloody, and very different from cataract surgery, to say the least. The tumor was fairly vascularized, overtaking the blood supply that normally “belongs to the brain.” Blood vessels were consistently cauterized to starve the tumor and isolate it from its blood supply prior to resection; if this cauterization was not done, even more bleeding would have occurred. After cauterization, the tumor took on a more purple appearance, reflecting the devascularization. A device was used to break up the tumor, in a manner analogous to phacoemulsification. Main areas of focus/concern were the middle meningeal artery and the middle cerebral artery (MCA). The MCA was exposed at various points because the tumor had overtaken some of its branches. The surgeon indicated that tumors behave differently than aneurysms in the sense that the tumor’s role in disrupting the blood supply can be less predictable. This may lead to vascular “spasm” and result in the unfortunate outcome of hemispheric stroke in some cases.
Newfound appreciation
There is an adage in neurosurgery: “90% of the tumor takes 10% of the time to remove. The other 10% takes 90% of the time.” The center of the tumor is relatively easy to identify and dissect/remove. Care must then be taken to carefully evaluate the surrounding anatomy.
The surgeon found a sneaky dural tail of tumor that was extending along neural tissue, seemingly looking for a blood supply and pathway for growth. It is critical to remove as much of the lesion as is safe to minimize morbidity from residual tumor or recurrence. Multiple areas of tumor were detected throughout the brain and within the sphenoid bone itself. The resected fragments were sent to pathology to confirm various characteristics and features of the lesions.
Surgery took nearly 8 hours. The surgeon took zero breaks. No water, no food, no bathroom breaks. Just brain surgery for 8 hours.
This experience, for me, was profound. Visualizing the optic nerve through the neuro-microscope was something I will truly never forget. I gained a newfound appreciation for the intricacies of neuroanatomy, how jam-packed every critical structure is next to one another and how incredible it is that human beings can perform (and recover from) such an operation. Fortunately, the patient recovered well, and vision has remained stable following his surgery.
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Joseph (Joey) Kane, OD, FAAO, is an attending optometrist with the VA Boston Healthcare System. He practices medical optometry in an outpatient hospital setting and works alongside optometry students and residents as a clinical preceptor. He can be reached at joeykaneod@gmail.com.
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