For patients undergoing surgery for low-grade glioma, who must be “awake” to facilitate mapping, hypnosis allows surgeons to safely remove the tumor up to functional boundaries, according to a first-of-its-kind study.
Hypnosis also had a positive psychologic impact on most of the patients treated in the small series.
“The asleep–awake–asleep procedure is usually the best procedure for this surgery, but when patients are old, they need more time to wake up from the first step, so the intraoperative neuropsychologic assessment is difficult to do during the first 10 to 30 minutes,” said lead researcher Ilyess Zemmoura, MD, PhD, from the CHRU de Tours, Bretonneau Hospital, in France.
“It can be difficult for the surgeon to know if a patient is making errors because of anesthesia or because of the tumor resection,” he told Medscape Medical News. “Hypnosis could be a valuable alternative for older patients who are not candidates for asleep–awake–asleep anesthesia.”
The study was published in the January issue of Neurosurgery.
All participants were candidates for an awake craniotomy for low-grade glioma resection from May 2011 to April 2015, and were offered hypnosedation. Two patients with a high-grade glioma were also offered hypnosedation.
Patients with high-grade gliomas often have an existing neurologic deficit that contraindicates awake surgery, but if they have an intact neurologic exam prior to surgery, they too would be candidates for awake surgery and possibly hypnosis, Dr Zemmoura explained.
One month before surgery, patients underwent a complete neuropsychologic assessment, among other procedures. They also underwent a short hypnosis session so they could learn how to envision an imaginary place where they could feel safe.
The team assessed the patients’ experience of the surgery using the Cohen Perceived Stress Scale (PSS), an overall measure of stress, and the Posttraumatic Stress Disorder Checklist Scale (PCLS). To evaluate the hypnosis experience, they used the Peritraumatic Dissociative Experiences Questionnaire (PDEQ).
Thirty-seven patients underwent 43 successful hypnosedation procedures (six patients underwent reoperation after regrowth of the tumor during the study). The hypnosedation procedure failed in six patients, who were immediately converted to asleep–awake–asleep anesthesia.
Twenty-five of the 37 patients completed 28 questionnaires (three of the patients had undergone reoperation), which revealed that there was little or no negative psychologic impact of the procedure on the patients and that most of the patients achieved a hypnotic trance state.
Pathologic scores of stress on the PSS scale were seen in eight patients. Evidence of dissociation on the PDEQ scale was seen in 17 patients, suggesting that these patients achieved a hypnotic state, whereas the remainder did not.
However, the PDEQ scale was developed to assess post-traumatic stress disorder (PTSD) and, as such, is not a good questionnaire to assess the induction of hypnosis during surgery, Dr Zemmoura explained.
PTSD on the PCLS scale was detected in one patient, but like many of the patients who did not show dissociation on the PDEQ questionnaire, this patient had a particularly good experience with hypnosis, the researchers report.
Hypnosis also appeared to reduce the effect of unpleasant events during surgery, including the burr hole procedure and bone flap removal — the two procedures patients most frequently cited as being unpleasant. These procedures, which involve a head clamp, are obviously felt by the patient, even if they are not painful, the researchers note.
Interestingly, local anesthesia of the scalp, by far the most painful preincision step, was reported by patients as unpleasant least often.
For the most part, the surgical course was uneventful in this series of patients. During the hypnosedation procedure, five patients had focal seizures that ceased after irrigation of the brain with cold saline, seven patients experienced nausea, and five patients vomited during or after the resection.
One patient died in the immediate postoperative period from unexplained ischemia of both middle cerebral arteries, and another patient developed a new neurologic deficit. The postoperative period was uneventful for the other 41 procedures.
Only two patients stated that they would not choose hypnosedation if they had to undergo a second awake surgery.
The researchers report that they now systematically use ropivacaine to reduce any pain that patients might feel during skin closure and, when possible, they intubate patients or use a laryngeal mask for the end of surgery.
The aims of the hypnosedation procedure were to improve the comfort of patients during surgery and to enhance their postoperative quality of life “by avoiding the traumatism created by awake surgery,” Dr Zemmoura and colleagues state.
“By showing a very low rate of failure of hypnosis, our results confirm the effectiveness of hypnosis in a new surgical application, brain tumor resection,” they note. In addition, the results suggest that individual hypnotizability depends mostly on the patient’s subjective experience.
Dr Zemmoura’s team is now trying to better identify which patients are suggestible to hypnosis and which are not so they can exclude patients who are not likely to respond to hypnosis and proceed directly to asleep–awake–asleep anesthesia.
The authors have disclosed no relevant financial relationships.
Neurosurgery. 2016;78:53-61. Abstract