Augmented Reality-Assisted Percutaneous Rhizotomy for Trigeminal Neuralgia
BACKGROUND:Percutaneous rhizotomy of the trigeminal nerve is a common surgery to manage medically refractory trigeminal neuralgia. Traditionally, these procedures have been performed based on anatomic landmarks with fluoroscopic guidance. Augmented reality (AR) relays virtual content on the real world and has the potential to improve localization of surgical targets based on preoperative imaging. OBJECTIVE:To study the potential application and benefits of AR as an adjunct to traditional fluoroscopy-guided glycerol rhizotomy (GR). METHODS:We used traditional fluoroscopy-guided percutaneous GR technique as previously described, performed under general anesthesia. Anatomic registration to the Medivis SurgicalAR system was performed based on the patient's preoperative computerized tomography, and the surgeon was equipped with the system's AR goggles. AR was used as an adjunct to fluoroscopy for trajectory planning to place a spinal needle into the medial aspect of the foramen ovale. RESULTS:A 50-year-old woman with multiple sclerosis-related right-sided classical trigeminal neuralgia had persistent pain, refractory to medications, previous gamma knife stereotactic radiosurgery, and percutaneous radiofrequency rhizotomy performed elsewhere. The patient underwent AR-assisted fluoroscopy-guided percutaneous GR. The needle was placed into the right trigeminal cistern within seconds. She was discharged home after a few hours of observation with no complications and reported pain relief. CONCLUSION/CONCLUSIONS:AR-assisted percutaneous rhizotomy may enhance the learning curve of these types of procedures and decrease surgery duration and radiation exposure. This allowed rapid and correct placement of a spinal needle through the foramen ovale.
The historical evolution of microvascular decompression for trigeminal neuralgia: from Dandy's discovery to Jannetta's legacy
Although the symptoms of trigeminal neuralgia (TN) have been well described throughout the history of medicine, its etiology was initially not well understood by most surgeons. The standard procedure used to treat TN today, microvascular decompression (MVD), evolved due to the efforts of numerous neurosurgeons throughout the twentieth century. Walter Dandy was the first to utilize the cerebellar (suboccipital) approach to expose the trigeminal nerve for partial sectioning. He made unique observations about the compression of the trigeminal nerve by nearby structures, such as vasculature and tumors, in TN patients. In the 1920s, Dandy unintentionally performed the first MVD of the trigeminal nerve root. In the 1950s, Palle TaarnhÃ¸j treated a TN patient by performing the first intentional decompressive procedure on the trigeminal nerve root solely through the removal of a compressive tumor. By the 1960s, W. James Gardner was demonstrating that the removal of offending lesion(s) or decompression of nearby vasculature alleviated pressure on the trigeminal nerve and the pain associated with TN. By the 1990s, Peter Jannetta proved Dandy's original hypothesis; he visualized the compression of the trigeminal nerve at the root entry zone in TN patients using an intraoperative microscope. In this paper, we recount the historical evolution of MVD for the treatment of TN.
History of Hemostasis in Neurosurgery
Control of bleeding in the confined area of the skull is imperative for successful neurosurgery and the prevention of devastating complications such as postoperative hemorrhage. This paper reviews the historical evolution of methods to achieve successful hemostasis in neurosurgery from the early1800s to today. The major categories of hemostatic agents (mechanical, chemical and thermal) are delineated and discussed in chronological order. The significance of this article is in its detailed history of the kinds of hemostatic methods that have evolved with our accumulating medical and surgical knowledge, which may inform future innovations and improvements.
Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip
OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p < 0.001). Measures for CN VI were most prominently affected. The area under the curve (AUC) for eye-tracking metrics to discriminate between ICP < 12 and >/= 12 mm Hg was 0.798. To discriminate an ICP < 15 from >/= 15 mm Hg the AUC was 0.833, and to discriminate ICP < 20 from >/= 20 mm Hg the AUC was 0.889. CONCLUSIONS Increasingly elevated ICP was associated with increasingly abnormal eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.
A matched cohort comparison of clinical outcomes following microsurgical resection or stereotactic radiosurgery for patients with small- and medium-sized vestibular schwannomas
OBJECTIVE A randomized trial that compares clinical outcomes following microsurgery (MS) or stereotactic radiosurgery (SRS) for patients with small- and medium-sized vestibular schwannomas (VSs) is impractical, but would have important implications for clinical decision making. A matched cohort analysis was conducted to evaluate clinical outcomes in patients treated with MS or SRS. METHODS The records of 399 VS patients who were cared for by 2 neurosurgeons and 1 neurotologist between 2001 and 2014 were evaluated. From this data set, 3 retrospective matched cohorts were created to compare hearing preservation (21 matched pairs), facial nerve preservation (83 matched pairs), intervention-free survival, and complication rates (85 matched pairs) between cases managed with SRS and patients managed with MS. Cases were matched for age at surgery (+/- 10 years) and lesion size (+/- 0.1 cm). To compare hearing outcomes, cases were additionally matched for preoperative Class A hearing according to the American Academy of Otolaryngology-Head and Neck Surgery guidelines. To compare facial nerve (i.e., cranial nerve [CN] VII) outcomes, cases were additionally matched for preoperative House-Brackmann (HB) score. Investigators who were not involved with patient care reviewed the clinical and imaging records. The reported outcomes were as assessed at the time of the last follow-up, unless otherwise stated. RESULTS The preservation of preoperative Class A hearing status was achieved in 14.3% of MS cases compared with 42.9% of SRS cases (OR 4.5; p < 0.05) after an average follow-up interval of 43.7 months and 30.3 months, respectively. Serviceable hearing was preserved in 42.8% of MS cases compared with 85.7% of SRS cases (OR 8.0; p < 0.01). The rates of postoperative CN VII dysfunction were low for both groups, although significantly higher in the MS group (HB III-IV 11% vs 0% for SRS; OR 21.3; p < 0.01) at a median follow-up interval of 35.7 and 19.0 months for MS and SRS, respectively. There was no difference in the need for subsequent intervention (2 MS patients and 2 SRS patients). CONCLUSIONS At this high-volume center, VS resection or radiosurgery for tumors = 2.8 cm in diameter was associated with low overall morbidity. The need for subsequent intervention was the same in both groups. SRS was associated with improved hearing and facial preservation rates and reduced morbidity, but with a shorter average follow-up period. Facial function was excellent in both groups. Since patients were not randomly selected for surgery, different clinical outcomes may be of different value to individual patients. Both anticipated medical outcomes and patient goals remain the drivers of treatment decisions.
A matched cohort comparison of facial nerve outcomes in salvage surgery after stereotactic radiosurgery for progressive vestibular schwannomas compared with microsurgery alone [Meeting Abstract]
Background: Salvage surgery for progressive symptoms or recurrent growth of vestibular schwannoma (VS) after stereotactic radiosurgery (SRS) is uncommon. It has been reported to be more difficult, the same or easier than expected compared with microsurgical resection (MS) of treatment-naive VS, with variable facial nerve outcomes. We conducted a matched cohort analysis to evaluate facial nerve outcomes for patients undergoing MS for progressive symptoms or recurrent growth of VS after SRS compared with MS for treatment-naive VS. Methods: We evaluated the records of 365 non-NF2 VS patients treated with MS from 2001 to 2014. All patients who had postoperative notes were considered to have "adequate follow-up" and included in the study. Nine patients underwent resection for VS after prior SRS (MS-POST SRS) with no prior intervention, 7 of which had adequate follow-up, and 331 patients that underwent MS for treatment naive VS (MS-NO SRS), 317 of which had adequate follow-up. From this dataset, we created propensity score matched cohorts to retrospectively compare facial nerve preservation and clinical outcomes. The propensity score model incorporated age at surgery, tumor size, and pre-operative HB grade, and cases were matched at a ratio of 4:1 MS-NO SRS to MS-POST SRS cases. Results: The MS-POST SRS (n = 7) and MS-NO SRS (n = 28) groups differed only in preoperative hearing status (p < 0.01). Preoperative HB grades were similar between MS-POST SRS and MS-NO SRS groups (p>0.3). The average time-to-intervention after SRS in the MS-POST SRS group was 44.4 months. The indication for MS after SRS was symptom progression with tumor growth in 4 cases, and only tumor growth in the remaining 3. Postoperatively, 3 cases in the MS-POST SRS group demonstrated improvement in HB grade and none became worse whereas 3 of 28 cases in the MS-NO SRS group demonstrated improvement and 12 cases had decrement in HB grade relative to baseline (p < 0.05). There was no significant difference in the extent of resection with both cohorts (MS-POST SRS and MS-NO SRS) attaining gross total resection in 85.7% of cases. Subsequent intervention was not required for any case in the MS-POST SRS group and 2 cases in the MS-NO SRS group, although this difference was not significant. Both cases requiring subsequent intervention in the MS-POST SRS group were gross total resections via the translabyrinthine approach, with subsequent intervention required at 62 and 48 months. There were no significant differences in the complication rate for individual complications or the overall complication rate between cohorts. Conclusions: At a center with high clinical volume, microsurgical resection of VS after prior SRS was associated with good postoperative facial nerve preservation and low morbidity, comparable to those observed in resection of treatment-naive VS. In addition there were similar outcomes in terms of extent of resection between the two groups. The good outcomes reported here may reflect a confluence of factors which include patient selection, the experience of the attending surgeons, the use of more contemporary SRS dosing protocols during initial treatment for these patients, and divergent goals of therapy between cohorts
Prevalence of Asymptomatic Incidental Aneurysms: A Review of 2685 Computed Tomographic Angiograms
OBJECTIVE: Intracranial aneurysms are a public health issue with a potential for rupturing, causing significant morbidity/mortality. The prevalence of unruptured intracranial aneurysms, including those that are asymptomatic, varies largely, since it has been determined through autopsy studies as well as conventional angiography. However, computed tomography (CT) angiography, a less invasive procedure, has replaced the use of conventional angiography in the recent decades. The objective of the present study is to determine the prevalence of incidental aneurysms. METHODS: The present study reviews all CT angiography cases within the last decade at a single institution. RESULTS: Out of 2195 cases included in the study, 39 (1.8%) were found to have asymptomatic unruptured aneurysms. CONCLUSION: An increased number of asymptomatic incidental aneurysms was detected.
Management of sinonasal hemangiopericytomas: a systematic review
BACKGROUND: Hemangiopericytomas are typically found in soft-tissue, but only rarely found in the sinonasal tract. Sinonasal hemangiopericytomas have been reported mostly through case studies, and optimal treatment is considered surgical excision. Classically, open surgical methods of tumor extirpation have been considered standard of care. With the wider use of endoscopic methods, an updated systematic review in terms of treatment is warranted. METHODS: Cases were identified using a MEDLINE and PubMed search. Relevant studies were identified, and data was extracted regarding patient demographics, presenting symptoms, tumor characteristics, treatment, and outcomes. RESULTS: A total of 128 cases were collected from 56 articles, consisting of case reports and series. The most common presenting symptoms were epistaxis, nasal obstruction, and facial pain/swelling/pressure. Computed tomography (CT) and X-ray were the most common modes of imaging during diagnosis and operative planning. The tumor often occupied multiple locations in the sinonasal tract at initial presentation. Surgical resection was the mainstay of treatment in 126 of the 128 cases (98.4%), either through open resection or endoscopic techniques. Surgical removal resulted in no recurrence in 79.7% of the cases. The use of endoscopic techniques increased significantly in the past decade. This review found no significant difference in terms of recurrence between endoscopic and open treatment groups, age, gender, and unilocality vs multilocality of tumor. CONCLUSION: Surgical management remains the mainstay of treatment for hemangiopericytomas. Endoscopic resection of these lesions has increased over the last few decades and has become a safe, viable, and reasonable alternative to open resection.
In-Office Jones tube exchange using the Seldinger technique
Conjunctivodacryocystorhinostomy (CDCR) with Jones tube placement is usually performed as a primary procedure for severe stenosis or obstruction of both upper and lower canaliculi of the lacrimal drainage pathway, or occasionally, after unsuccessful dacryocystorhinostomy (DCR). Jones tube obstruction is quite common, and often requires removal of the obstructed tube and replacement or exchange of the tube in the operating room. This procedure is typically performed under general anesthesia, and is associated with the risks of general anesthesia, a significant investment of time, and the cost of the operating suite. Recently, there has been a movement toward in-office procedures in otolaryngology and ophthalmology due to greater patient satisfaction and savings in time and money for patients and physicians. In this report, we describe a novel in-office method to exchange an obstructed Jones tube that provides the aforementioned benefits while preserving patient comfort. No similar case has been previously reported in the literature.
In-office vasovagal response after rhinologic manipulation
BACKGROUND: Advances in endoscopic sinus surgery have led to a greater number of in-office procedures away from the traditional operating room setting. Rhinologists acting independently of anesthesiologists must be prepared for potential complications, such as vasovagal response (VVR), that may arise during in-office rhinologic manipulations. In this study, we review our experience with this condition and discuss risk factors and a management algorithm for in-office VVR. METHODS: A retrospective analysis at a large tertiary referral center was performed on all patients undergoing in-office endoscopic procedures with rhinologic manipulation between July 2008 and June 2012. A total of 4973 patients underwent in-office endoscopic procedures and 8 patients with VVR were identified. Demographic data, diagnosis, procedure performed, and outcomes were reviewed. RESULTS: Eight patients out of 4973 (0.16%) experienced VVR during in-office endoscopic procedures. Seven (87.5%) of these 8 patients recovered from the VVR within 30 minutes and subsequently completed their scheduled procedure. One (12.5%) of the 8 patients did not fully recover after 30 minutes and was sent to the Emergency Department, where he was stabilized and subsequently discharged. The most common comorbidities in these 8 patients with VVR were hypercholesterolemia in 3 patients (37.5%), and hypertension and benign prostatic hyperplasia, each found in 2 patients (25.0%). CONCLUSION: Although the incidence of VVR during rhinologic procedures is low, rhinologists should be familiar with this condition and be prepared for its management.