The traditional way to reach a deep-seated lesion within the brain is through an open craniotomy. While this route is effective at accomplishing the primary goal of accessing the tumor, it’s littered with collateral damage, says Johns Hopkins neurosurgeon Kaisorn Chaichana.
“It usually requires a big incision, a big opening in the skull, a big opening in the dura,” he says. “As we dissect downward, we’re compromising the white matter the whole time.” The end result, he adds, is substantial blood loss, long hospital stays, long recovery times and an increased risk of damage to brain structures, which can cause neurological deficits.
Enter the minimally invasive tubular retractor, a device that Chaichana has recently incorporated into many of the procedures he’s performed to help mitigate these issues. With a tubular diameter slightly less than a nickel, this retractor allows for less invasive brain surgery by using an obturator with an atraumatic tip to push white matter away instead of cutting it.
During procedures that use this device, Chaichana and his colleagues typically rely on MRI with diffusion tensor imaging data gathered before surgery to guide an interoperative navigation system. Using these data to pinpoint the location of a lesion, the surgeons make a small opening about the size of a silver dollar through the scalp, skull and dura. They then insert the tubular retractor between white matter tracts directly over the tumor.
Once the obdurator is in place, the surgeons can remove an inner metal insert, leaving behind an inner clear sheath. The surgery is performed with an exoscope—a small camera that hovers over the surgical field—and tools to go within the device. Using this protocol, Chaichana and his colleagues can resect entire tumors with minimal disruption to the surrounding brain structures.
This approach is particularly valuable for tumors in eloquent locations, Chaichana says. Treating these tumors using traditional surgical methods would increase the result in motor, language or visual field deficits because of the large dissection of the critical brain matter. However, in the 30 cases he’s already treated using this device over the past year, these functions have been largely preserved. These patients have also had shorter surgeries, significantly less blood loss, shorter hospital stays and quicker recoveries, he adds.
Because of its host of benefits, Chaichana says, he expects that use of this device will grow throughout this field over time.
“With this approach, we can offer patients the same great results as an open resection,” he says, “while also giving them a much greater chance of preserving their neurological function and quality of life.”
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