SCOTTSDALE, Ariz.—An endoscopic approach to sinonasal malignant tumors is coming into its own, but the literature on the topic is still lacking and physicians must recognize its limitations, said a panel of experts here on Jan. 25 at the Triological Society’s Combined Sections Meeting.
A new era might be dawning on the removal of these malignancies, said Marc Rosen, MD, associate professor of otolaryngology/head and neck surgery at Thomas Jefferson University Hospitals in Philadelphia. “With the combination of the bicoronal approach with the endoscope [the open endoscopic or cranioendoscopic approach], I really think that this could be the end of open facial incisions such as lateral rhinotomy and midface de-gloving for the treatment of sinonasal malignancies,” he said.
The endoscopic approach might allow for better margins due to current technology, including better illumination, magnification, panoramic view and navigation, he said. But, he stressed that it’s still not a surgery meant for the “casual” operator. “We typically have a multi-disciplinary approach with neurosurgery and ophthalmology (during the procedure) to improve outcomes,” he said. He added that surgeons should have a strong background in both head and neck cancer surgery and rhinology.
Review of the Evidence
Peter Hwang, MD, professor and director of the Stanford Sinus Center in Stanford, Calif., said that, in the end, the literature sorts out what is “a surgical fad” and what is a “durable shift in practice.” The problem is that the literature now is filled with studies that include many different tumor types, without much data for each type. And the tumors tend to be smaller in endoscopic approaches, making comparisons with an open approach, which generally involves larger tumors, difficult. “This is not a mature body of literature, and I think that’s a lot of the problem we’re having right now,” Dr. Hwang said. “We’re trying to figure out what the literature says about the efficacy of endoscopic approaches.”
For instance, he said, the most comprehensive study focused on the tumor type esthesioneuroblastoma is a meta-analysis published in 2009 (Laryngoscope. 2009;119:1412-1416). The study involved 361 participants from 28 studies. But, there was an unequal distribution of tumor stages—to a statistically significant degree—between the endoscopic and open approaches. “So definitive conclusions are therefore not possible from this, the highest level of evidence for esthesioneuroblastoma,” he said.
At this time, he added, there’s no evidence to suggest that endoscopic approaches are superior to open approaches in terms of oncologic control. “We definitely need more data to compare outcomes for advanced-stage tumors,” he said. “Ideally, we would like to see tumor-specific, stage-specific comparisons collected prospectively in order to validate the endoscopic approach to sinonasal malignancy. Once we can establish the equivalency on an oncologic basis, then we may see some differentiation based on quality of life outcomes between endoscopic and open approaches.”
Alexander Chiu, MD, chief of otolaryngology-head and neck surgery at the University of Arizona in Tucson, said the goals of the endoscopic approach and the open approach are mostly the same—a gross total resection, negative margins, sparing of vital organs and avoidance of neurological complications. But, with the endoscopic approach, another goal is the en bloc resection of the tumor attachment site, rather than of the whole tumor, to prevent recurrence.
In video footage, he showed a microdebrider suctioning away and debulking the tumor, which gives a better view of the attachment site, where the tumor can then be resected with a negative margin. “The first half-hour of the case is the most important part of the case,” he said. “That’s where you really want to debulk quickly in order to limit your blood loss.”
In some cases, it becomes clear that the attachment site can’t be resected endoscopically. “You have to be prepared to do an open procedure,” said Dr. Chiu. “I’m not doing this patient any favors by debulking her tumor without addressing that site of attachment.”
The panelists said that they review with patients the possibility of having to move to a more invasive procedure, and most patients are receptive to that if it means helping them in the long term. “These patients are pretty shell-shocked,” Dr. Chiu said. “They’re scared about their cancer; they just want it taken care of.”
Adam Zanation, MD, assistant professor of otolaryngology/head and neck surgery at the University of North Carolina Chapel Hill School of Medicine, who reviewed complications with endoscopic skull base surgery and sinonasal malignancy procedures, said that in reading the literature, it’s important to consider whether the outcomes reported are in the context of the “current state” of the field. “Is this really what we’re dealing with today? Is that what we should be telling our patients?” he said.
A review of 800 cases of endonasal skull base surgery published in 2011, for instance, found that data were less relevant because so few of the patients had received nasoseptal flap and vascular reconstructions, which have now become routine. Dr. Zanation is now working on a study that shows a lower rate of post-operation cerebrospinal fluid leaks than was found in the former study. “I think they’re overestimated in the current literature,” he said. “As the reconstructive techniques have advanced, the post-operative complications have continued to get better.” Intra-operative neurovascular injury, although rare, can be devastating, however.
Preventing intra-operative nerve injury involves active nerve monitoring, image guidance, nerve stimulator dissection, selectiveness about using bipolar cautery, and the use of irrigation. He added that it’s important to counsel patients about the nerve injury risks, especially since damage usually won’t be apparent until the patient wakes up from the surgery.
Arterial injury is rare, and the keys to its prevention are having an experienced team and sometimes getting an open control of the neck vessels before the procedure. But, once an injury happens, managing it right away is crucial, by keeping arterial pressures high for brain perfusion, getting quick blood transfusions and working in spurts to let blood transfusions keep pace, Dr. Zanation said.
He said that in a review of cases from his institution, only four of 334 patients had intra-operative arterial bleeds, and none had permanent neurological deficits. He added that the long-term stroke risk is unknown, however.
These procedures can be tiring, he said, and it’s important to ask for help when it’s needed. “That’s probably my biggest pearl,” he said. “You’re going to do these long cases. [If] you get a problem at the end of a long case, don’t be afraid to call your partners and say, ‘Hey, I just need a fresh set of hands and a fresh set of eyes.’”