title: Complication avoidance in laser interstitial thermal therapy: lessons learned.
abstract: OBJECTIVE Complications of laser interstitial thermal therapy (LITT) are underreported. The authors discuss how they have modified their technique in the context of technical and treatment-related adverse events. METHODS The Medtronic Visualase system was used in 49 procedures in 46 patients. Between 1 and 3 cooling catheters/laser fiber assemblies were placed, for a total of 62 implanted devices. Devices were placed using frameless stereotaxy (n = 3), frameless stereotaxy with intraoperative MRI (iMRI) (n = 9), iMRI under direct vision (n = 2), MRI alone (n = 1), or frame-based (n = 47) techniques. LITT was performed while monitoring MRI thermometry. Indications included brain tumors (n = 12), radiation necrosis (n = 2), filum terminale ependymoma (n = 1), mesial temporal lobe epilepsy (n = 21), corpus callosotomy for bifrontal epilepsy (n = 3), cavernoma (n = 1), and hypothalamic hamartomas (n = 6). RESULTS Some form of adverse event occurred in 11 (22.4%) of 49 procedures. These included 4 catheter malpositions, 3 intracranial hemorrhages, 3 cases of neurological deficit related to thermal injury, and 1 technical malfunction resulting in an aborted procedure. Of these, direct thermal injury was the only cause of prolonged neurological morbidity and occurred in 3 of 49 procedures. Use of frameless stereotaxy and increased numbers of devices were associated with significantly increased complication rates (p < 0.05). A number of procedural modifications were made to avoid complications, including the use of 1) frame-based catheter placement, a 1.8-mm alignment rod to create a track and titanium skull anchors for long trajectories to improve accuracy; 2) a narrow-gauge instrument for dural puncture and coregistration of contrast MRI with CT angiography to reduce intracranial hemorrhage; 3) general endotracheal anesthesia for posterior-placed skull anchors to reduce the likelihood of damage to the cooling catheter; 4) use of as few probes as possible to reduce complications overall; and 5) dose modification of thermal treatment and use of short (3-mm) diffusing tips to limit treatment when structures to be spared do not have intervening CSF spaces to act as heat sinks. CONCLUSIONS Laser ablation treatment may be used for a variety of neurosurgical procedures for patients with tumors and epilepsy. While catheter placement and thermal treatment may be associated with a range of suboptimal operative and postoperative courses, permanent neurological morbidity is less common. The authors' institutional experience illustrates a number of measures that may be taken to improve outcomes using this important new tool in the neurosurgical arsenal.
authors.affiliation: Hofstra Northwell School of Medicine, Hempstead; and.
authors.forename: Rachel
authors.initials: R
authors.lastname: Pruitt
authors.affiliation: Departments of 2 Neurosurgery and.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gamble
authors.affiliation: Hofstra Northwell School of Medicine, Hempstead; and.|Radiology, North Shore University Hospital, Manhasset, New York.
authors.forename: Karen
authors.initials: K
authors.lastname: Black
authors.affiliation: Hofstra Northwell School of Medicine, Hempstead; and.|Departments of 2 Neurosurgery and.
authors.forename: Michael
authors.initials: M
authors.lastname: Schulder
authors.affiliation: Hofstra Northwell School of Medicine, Hempstead; and.|Departments of 2 Neurosurgery and.
authors.forename: Ashesh D
authors.initials: AD
authors.lastname: Mehta
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D001927:Brain Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D055815:Young Adult
keywords: CTA = CT angiography; HIFU = high-intensity focused ultrasound; LITT; LITT = laser interstitial thermal therapy; PAD = precision aiming device; SRS = stereotactic radiosurgery; iMRI = intraoperative MRI; laser interstitial thermal therapy; minimally invasive neurosurgery; surgical technique