Ultrasonic Aspirator Research Articles

Improving safety of robotic major hepatectomy with extrahepatic inflow control and laparoscopic CUSA parenchymal transection: technical description and initial experience.

Blood loss is a major determinant of outcomes following hepatectomy. Robotic technology enables hepatobiliary surgeons to mimic open techniques for inflow control and parenchymal transection during major hepatectomy, increasing the ability to minimize blood loss and perform safe liver resections. Initial experience of 20 consecutive major robotic hepatectomies from November 2018 to July 2020 at two co-located institutions was reviewed. All cases were performed with extrahepatic inflow control and parenchymal transection with the laparoscopic cavitron ultrasonic surgical aspirator (CUSA), and a technical description is illustrated. Clinical characteristics, operative data, and surgical outcomes were retrospectively analyzed. The median (range) patient age was 58years (20-76) and the majority of 14 (70%) patients were ASA III-IV. There were 12 (60%) resections for malignancy and the median tumor size was 6.2cm (1.2-14.6). Right or extended right hepatectomy was the most common procedure (12 or 60% of cases). There were 7 (35%) left or extended left hepatectomies and 1 (5%) central hepatectomy. The median operative time was 420 (177-622) minutes. Median estimated blood loss was 300mL (25-800mL). One (5%) case was converted to open. Two (10%) patients required blood transfusion. The median length of stay was 3 (1-6) days. Major complications included 1 (5%) Clavien-Dindo IIIa bile leak requiring percutaneous drainage placement. There was no 90-day mortality. Advanced techniques to reduce blood loss in robotic hepatectomy may optimize safety and minimize morbidity in these complex minimally invasive procedures.

FFPE samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas.

During surgical procedures for gliomas, tissue material obtained from cavitational ultrasonic surgical aspirators (CUSAs) is generally discarded but can actually exceed the amount and quality of certain tumour core resections (TCRs). Despite reports indicating the suitability of CUSA-derived material for diagnosis and research, its use is still marginal. We extended these conclusions to formalin-fixed, paraffin-embedded (FFPE) samples, the most common format for archival tumour tissue in anatomical pathology departments, by conducting for the first time RNA-seq analysis in CUSA aspirates. We compared the molecular diagnosis of somatic mutations used in the clinical routine and the gene expression profiles of fixed solid material from CUSA aspirates and TCRs from the same patients in selected gliomas encompassing grades II to IV. Despite the characteristic heterogeneity of gliomas, we found substantial similarities between the corresponding aspirates and TCRs that included transcriptional signatures associated with glioma subtypes. Based on these results, we confirmed that CUSA-fixed biomaterials from glioma surgeries are appropriate for downstream applications and biomarkers screening.

Thrombectomy and Clip Occlusion of a Giant, Stent-Coiled Basilar Bifurcation Aneurysm: 3-Dimensional Operative Video.

Giant basilar apex aneurysms are associated with significant therapeutic challenges.1-6 Multiple techniques exist to treat giant basilar apex aneurysms, including direct clipping, stent-assisted coil embolization, and proximal occlusion with bypass revascularization.7-9 Hypothermic circulatory arrest was a useful adjunct for surgical repair of these aneurysms but has been abandoned because of associated risks.10,11 Rapid ventricular pacing can achieve similar aneurysm softening with minimal risks and assist in clip occlusion. This case illustrates clip occlusion of a giant, partially thrombosed, previously stent-coiled basilar apex aneurysm in a 15-yr-old boy with progressive cranial neuropathies and sensorimotor impairment. Although a wire was placed preoperatively for ventricular pacing, it was not needed during the procedure. Patient consent was obtained. A right-sided orbitozygomatic craniotomy transcavernous approach with anterior and posterior clinoidectomies was performed. The basilar quadrification was dissected, and proximal control was obtained. After aneurysm trapping, the aneurysm was incised and thrombectomized using an ultrasonic aspirator. Back-bleeding from the aneurysm was anticipated, and ventricular pacing was ready, but back-bleeding was minimal. With the coil mass left in place, stacked, fenestrated clips were applied in a tandem fashion to occlude the aneurysm neck. Indocyanine green videoangiography confirmed occlusion of the aneurysm and patency of parent and branch arteries. The patient was at a neurological baseline after the operation, with improvement in motor skills and cognition at 3-mo follow-up. This case demonstrates the use of trans-sylvian-transcavernous exposure, rapid ventricular pacing, and thrombectomy amid previous coils and stents to clip a giant, thrombotic basilar apex aneurysm. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Abordaje presigmoideo transpetroso (petrosectomía parcial) combinado con abordaje subtemporal transtentorial para meningioma petroclival

Introduction: Petroclival meningiomas constitute 3 to 10% of meningiomas of the posterior fossa, they originate in the petroclival fissure, in the upper part of the clivus, petrosal apex, and medial to the trigeminal nerve. Resection of these tumors is a neurosurgical challenge. The combined partial petrosectomy approach associated with a sub-temporal approach is a technique described by various authors; however, its performance is considered highly complex. We report the case of a petroclival meningioma operated successfully in our hospital using a combined presigmoid and subtemporal transtentorial transpetrosal approach. Clinical case: 33-year-old female patient with a clinical picture of headache, nausea, and gait disturbance. Brain magnetic resonance imaging showed a large right petroclival tumor (4.2x3.9x3.8cm) that displaced the brainstem and secondary hydrocephalus. The hydrocephalus was treated with a ventricular peritoneal shunt. Then, the tumor was resected using a combined presigmoid and subtemporal transpetrosal approach, a technique that allowed adequate exposure of the tumor, achieving complete resection, without intraoperative complications. Postoperative evolution was favorable, with no sequelae. Conclusion: The combined presigmoid and transtentorial subtemporal transpetrous approach for petroclival meningiomas is an effective and feasible technique to perform in our environment. The support of technology such as Neuronavigation, the ultrasonic aspirator, intraoperative monitoring, and adequate experience in skull base surgery are fundamental factors for the success of this surgery. Keywords: Meningioma, Skull Base Neoplasms, Craniotomy, Neurosurgical Procedures. (Source: MeSH NLM)

Utilization of Discarded Surgical Tissue from Ultrasonic Aspirators to Establish Patient-Derived Metastatic Brain Tumor Cells: A Guide from the Operating Room to the Research Laboratory.

Patient-derived cells from surgical resections are of paramount importance to brain tumor research. It is well known that there is cellular and microenvironmental heterogeneity within a single tumor mass. Thus, current established protocols for propagating tumor cells in vitro are limiting because resections obtained from conventional singular samples limit the diversity in cell populations and do not accurately model the heterogeneous tumor. Utilization of discarded tissue obtained from cavitron ultrasonic surgical aspirator (CUSA) of the whole tumor mass allows for establishing novel cell lines in vitro from the entirety of the tumor, thereby creating an accurate representation of the heterogeneous population of cells originally present in the tumor. Furthermore, while others have described protocols for establishing patient tumor lines once tissue has arrived in the research lab, a primer from the operating room (OR) to the research lab has not been described before. This is integral, as basic research scientists need to understand the surgical environment of the OR, including the methods utilized to obtain a patient's tumor resection, in order to more accurately model cancer biology in laboratory. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Establishment of brain tumor cell lines from patient-derived CUSA samples: processing brain tumor sample from the OR to the lab Support Protocol 1: Sterilization of microsurgical tools in preparation for dissection Support Protocol 2: Collagen coating of tissue culture flasks Basic Protocol 2: Selection of tumor cells in vitro Support Protocol 3: FACS sorting tumor sample to isolate cancer cells from heterogeneous cell population.

Hepatectomy with Takasaki's Technique Using SonaStar Ultrasonic Aspiration System: An Experience from 58 Cases.

ObjectiveThis study aims to explore the short-term results of hepatectomy with Takasaki’s technique using Sonastar ultrasonic aspiration system.Materials and MethodsWe retrospectively examined data of 58 patients who underwent hepatectomy with Takasaki’s technique using Sonastar ultrasonic aspiration system at Hue Central Hospital from 01/2018 to 02/2021.ResultsThe mean age was 60.7 ± 10.5 years (25–80) and the male/female ratio was 6:1. Patients with solitary tumor accounted for 79%; 68.4% had tumor size greater than 5 cm. Pringle maneuver was used in 57.9%, while selective right or left Glissonean pedicle occlusion was used in 69.0% and 32.8%, respectively. Final transection surface reinforcement was achieved by Surgicel and BioGlue in 78.9% and 21.5% of cases, respectively. Major liver resection accounted for 73.7%. The mean parenchymal transection time was 50 (45–110) minutes, while mean total operative time was 125 (90–280) minutes. Mean operative blood loss was 250 (150–650) mL. Mean post-operative hospital stay was 8 days (7–23). Post-operative complication rate was 15.9% and mortality rate was 1.7%.ConclusionHepatectomy using Takasaki technique with Sonastar ultrasonic aspiration system is safe, effective, allowing an anatomical resection with sufficient safety margin and resulting in low complication rates (liver failure, biliary leakage) and good survival outcomes.

Acquisition of Basic Micro-Neurosurgical Skills Using Cavitron Ultrasonic Aspirator in Low-Cost Readily Available Models: The Egg Model

Attainment of micro-neurosurgical skills is a challenge in teaching hospitals throughout training. Models that mimic the workflow as well as haptics are time-consuming, expensive, and unsuitable to serve as a routine platform. Our objective was to present a model and a set of tasks, based on a hard-boiled egg, microscope, and a Cavitron ultrasonic aspirator (CUSA; Integra Lifesciences Corp., Tullamore, Ireland), which is cheap, easy to setup and can be used for training microsurgery and CUSA skills, required for removal of deep-seated tumors. The goal was to remove the egg yolk from within a hard-boiled egg, representing an intrinsic brain tumor, surrounded by the egg's white, representing adjacent brain tissue, while preserving it. Assessment was based on the yolk's exposure, completeness of removal, and collateral damage and task completion duration, with repeated trials (n= 4), for validation purposes, for 6 operators with different experience levels. Improvement in overall score (mean of 47.5 ± 19 in the first trial vs. 80.0 ± 12 in the fourth trial, P < 0.01), and task duration completion (mean initial duration of 21:25 ± 4:52 minutes to 15:30 ± 5:17 minutes, P < 0.01) was observed. Parameters gradually improved on repeated attempts, and experience level of the operators correlated with scores. The egg model is an easy-to-handle, cheap model that enables the acquisition of basic micro-neurosurgical skills and basic workflow required for removing of intrinsic brain tumors. This study has validated and defined reproducible tasks that can be scored, correlated with performance. This model can be incorporated into a resident's routine and potentially provide an accessible training platform for neurosurgical trainees.

Glioma Surgery and Surgical Supporting Technology

Maximum safe resection is the principal goal of glioma surgery to improve patient prognosis, and various skills and techniques are available to achieve this. First, detailed preoperative image assessment of the tumor, arteries, veins, and white matter is helpful in developing the surgical plan. Second, surgical supporting technology, such as a navigation system, electrophysiological monitoring, awake craniotomy, and fluorescence-guided surgery, are vital for glioma surgery. Third, and most importantly, neurosurgeons should develop surgical techniques. In this review, we will focus on the following points: how to determine and dissect the tumor boundary, how to preserve passing arteries and veins, how to identify and preserve the eloquent cortex and fibers, and how to treat bleeding during tumor removal. Dissection of the tumor margin includes sharp dissection and subpial dissection. Subpial dissection using a suction tube or Cavitron Ultrasonic Surgical Aspirator(CUSA)is often effective in glioma surgery, not only for achieving better resection, but also for the preservation of passing vessels. Using these techniques, excessively small vessels, such as perforating arteries, can be finely exposed and preserved during tumor resection. In this way, we should achieve an ideal balance between maximum tumor resection and patient quality of life.

O51: ARTIFICIAL INTELLIGENCE UTILIZING RECURRENT NEURAL NETWORKS TO CONTINUOUSLY MONITOR COMPOSITES OF SURGICAL EXPERTISE

Abstract Introduction Many surgical adverse events occur secondary to technical errors related to poor bimanual skills, fatigue and lack of the required expertise. We developed AI algorithms to continuously assess surgical bimanual technical performance during virtual reality simulated surgical tasks. To our knowledge, this is the first attempt in surgery to train AI algorithms to continuously monitor and evaluate bimanual skills comprehensively. Method Fifty individuals from four expertise levels (14 experts/neurosurgeons, 14 senior residents, 10 junior residents, 12 medical students) performed two virtual reality simulated surgical tasks with haptic feedback: a subpial tumor resection 5 times and a complex, realistically simulated brain tumor operation once. Each task required complete tumor removal while minimizing bleeding and damage to surrounding tissues using a simulated ultrasonic aspirator and a bipolar. A recurrent neural network continually tracked individual bimanual performance utilizing 16 performance metrics generated every 0.2 seconds. Result The recurrent neural network algorithm was successfully trained using neurosurgeons and medical students' data, learning the composites of expertise comparing high and lower skill levels. The trained algorithm outlined and monitored technical skills every 0.2 second continuously organizing performance of each surgical task into three levels: ‘excellent’, ‘average’ and ‘poor’. The percentage time spent on each level was calculated and significant differences found between all four groups for ‘excellent’ and ‘poor’ levels. Conclusion AI-powered surgical simulators provide an advanced assessment and training tool. AI's ability to continuous assess bimanual technical skills during surgery may further define the composites necessary to train surgical expertise. Abbrev AI: artificial intelligence Take-home message By advanced artificial intelligence algorithms surgeon's bi-manual technical skills can be assessed continuously, time periods of poor performance which increase the possibility of errors in performance can be identified.

Surgical removal of orbital tumors by orbital approach using ultrasonic surgical system SONOPET®

ABSTRACT Purpose Orbital tumor surgery can be challenging when the tumor is located in a very narrow surgical field and close to important structures, such as nerves or extraocular muscles that can be damaged during surgery. Advances in technology and special surgical techniques help to avoid such damage. We describe our experience using SONOPET® ultrasonic surgical aspirator to remove 12 different orbital tumors that were difficult to treat due to their poorly defined borders, adhesions, or location. Methods This is a retrospective case series that describes 12 operations that occurred between March 2016 to December 2018 using an ultrasonic device to debulk or remove orbital tumors. Different approaches and handpieces were used for each case depending on the location and consistency of the tumor. Results All patients experienced an improvement in preoperative signs and symptoms, pain, proptosis, diplopia, or lagophthalmos. Visual acuity, which had been reduced due to the tumor, was also recovered. There were no intraoperative or postoperative complications due to the use of the device. Conclusions The ultrasonic aspirator is a safe, useful device that can successfully remove or debulk infiltrating orbital masses through any orbital access, regardless of their consistency. It is helpful in cases of difficult anatomical access or difficult extraction due to size or adhesions to the surrounding tissues.

Lumbar Laminoplasty for Resection of Myxopapillary Ependymoma of the Conus Medullaris: 2-Dimensional Operative Video.

Myxopapillary ependymomas are slow-growing tumors that are located almost exclusively in the region of the conus medullaris, cauda equina, and filum terminale of the spinal cord. Surgical intervention achieving a gross total resection is the main treatment modality. If, however, a gross total resection cannot be achieved, surgery is augmented with radiation therapy. In this video, we present the case of a 27-yr-old male with persistent back pain and radiculopathy who was found to have a myxopapillary ependymoma that was adherent to the conus. Preoperative imaging demonstrated that the tumor was displacing the conus and nerve roots ventrally. A laminoplasty at L1-L2 was performed with near-total resection because of the intimate involvement of neural tissue. The key features of the video include performing laminoplasty and rationale, and performing maximum safe tumor resection with a combination of bipolar cautery, suction, and ultrasonic aspiration augmented with frequent stimulation, gel foam pledgets intradurally, and achieving a watertight closure of the dura and fascia. The patient tolerated the surgery well without any complications. Given his gross residual disease along the conus and young age, he was at a high risk for continued tumor growth without adjuvant therapy, with a recurrence rate of roughly 33% to 45% in patients who underwent subtotal resection. With the addition of adjuvant radiation therapy, the recurrence rate is 20% to 29%.1,2 He was discharged to home with a plan for conventional fractionated external beam radiation. At the most recent follow-up, he reported decreased back pain and radiculopathy. Appropriate patient consent was obtained.

Endoscopic Management of Intra Ventricular Tumours

Objective: Neuroendoscopic removal of intraventricular tumors is difficult and time consuming because of the lack of an effective decompression system that can be used through the working channel of the endoscope. The authors report on the utilization of an endoscopic ultrasonic aspirator in the resection of intraventricular tumors. Methods: Seventeen pediatric patients (14 male, 3 female), ages 1-15 years old, underwent surgery via a purely endoscopic approach using a Gaab rigid endoscope and endoscopic ultrasonic aspirator. Ten patients presented with an intraventricular tumor, three with paraventricular, and 4 with suprasellar lesions. Histology analysis showed 6/17 glial tumors, 3/17 with subependymal giant cell astrocytomas (associated with tuberous sclerosis), two cases presented with intraventricular metastases from high-grade tumors (medulloblastoma, atypical teratoid rhabdoid tumor), 4/17 with suprasellar tumors (2 craniopharyngiomas and 2 optic pathway gliomas), and two with pineal region tumors (1 immature teratoma, 1 PNET). In all patients, the endoscopic trajectory and ventricular access were guided by electromagnetic neuronavigation. Fifteen patients underwent surgery via a precoronal bur hole while supine. In 1 case, surgery was performed through a frontal anterior bur hole and one patient underwent surgery via a posterior parietal approach to the trigone while in a lateral position. The endoscopic technique consisted of visualization of the tumor, ventricular washing to dilate the ventricles and to control bleeding, obtaining a tumor specimen with biopsy forceps, and ultrasonic aspiration of the tumor. Bleeding was controlled with irrigation, monopolar coagulation, and a thulium laser. Results/Discussion: In 9 cases, the resection was total or near total (more than 90% of lesion removed). In 8 cases, the resection was partial or biopsy. Histological evaluation of the collected material (withdrawn using biopsy forceps and aspirated with an ultrasonic aspirator) was diagnostic in all cases. The duration of surgery ranged from 30 to 120 minutes. One case was complicated by subdural hygroma requiring a subduro-peritoneal shunt implant. The dry field technique was used in cases with persistence of bleeding. Conclusion: Patients harboring intraventricular tumors are in most cases ideal candidates for endoscopy biopsy/resection. In this series, endoscopic ultrasonic aspiration proved to be a safe and reliable method for achieving extensive decompression or complete removal in the management of intra- and/or paraventricular lesions in pediatric patients.

Tips and Tricks in Difficult ETV

The neuroendoscopy is supported by three pivotal pillars: training, planning, and prudence. The training consists of attending practical courses with synthetic head models for immersion in the intricate ventricular anatomy and practice in handling the neuroendoscope. The planning begins with the choice of the entry point, usually performed at the Kocher's point, and measurement of this to the ventricle. Neuroendoscopy in intraventricular hemorrhage or ventriculitis is always challenging due to low visibility, thus, copious irrigation with a heated solution at 37°C, like plasma type, is mandatory, often reaching 6L of solution. Narrow spaces between the clivus and basilar artery can be very dangerous, therefore we prefer a "Sputnik" fórceps rather than blunt instruments to open the floor of the III ventricle and subsequently widen it with Fogarty n°3. Sometimes it is necessary to mechanically remove the larger clots that do not come off the ventricle walls only with irrigation; in these cases, we aspirate them through the neuroendoscope until we see the structures that allow us to perform ETV and guarantee its patency. Navigating inside the ventricle when the complex anatomy is distorted, such as cases of myelomeningoceles with large interthalamic masses, can be very difficult; for these cases, we use the optics inversion technique to access different locations with the same field of view. The innovation in neuroendoscope models allowed us to associate techniques, such as the concomitant use of an ultrasonic aspirator to remove intraventricular lesions. Another field of great development was fetal surgery for hydrocephalus; initially with cephalocenteses passing through the ventriculo-aminiotic shunt until the fetal ETV. For complex cases of the second look of ETV, we can still associate techniques such as aqueductoplasty and implantation of stents in the third ventricular floor and cerebral aqueduct to keep them patent. Last but not least, we have the pillar of prudence. Any neuroendoscopy, regardless of the surgeon's experience or the apparent simplicity of the case, must be done with the utmost caution, avoiding minimal bleeding, avoiding touching structures that are not vital to the procedure, and be objective.

Brainstem tumors in children: a review

The brainstem is defined as the portion of the neural axis between the diencephalon and the cervical spinal cord. Brainstem gliomas (BSGs) can occur anywhere within this region and account for 10% to 15% of primary pediatric intracranial tumors. The development of neuroimaging allied to the refinement of surgical tools, such as improved magnification and visualization of the surgical field with more powerful surgical microscopes and sources of light, followed by the introduction of ultrasonic aspirator, anesthetic and intraoperative neurophysiological monitoring provided the neurosurgeon with conditions for a much safer surgical management of these tumors. This article reviews the current state of knowledge with regard to tumors arising in the brain stem in children, the therapeutic options available and provides recommendations with regard to management.&#x0D; &#x0D;

A randomized prospective study of the immediate outcomes of the use of a hydro-jet dissector and an ultrasonic surgical aspirator for laparoscopic liver resection

BackgroundNo prospective randomized trials comparing transection techniques for the liver parenchyma transection during laparoscopic liver resection have been performed. The aim of the study was to compare the immediate outcomes of hydro-jet dissection with ultrasonic surgical aspirator in laparoscopic liver parenchyma transection in a prospective randomized single-center study. MethodsConsecutive patients with liver benign and malignant tumors presenting to a single center from May 2017 to May 2020 were enrolled in the study. The primary endpoint was the intraoperative estimated blood loss. The secondary endpoints included duration of parenchymal transection, morbidity, and overall hospital stay. ResultsA total of 68 patients were enrolled in the study, with 34 patients in each group. There were no differences between groups in the difficulty of resection (according to IWATE criteria and IMM score) and other basic surgical parameters. No differences were found in all primary and secondary endpoints except the expenditure. The cost of equipment was significantly higher in the group of ultrasonic aspirator. ConclusionDespite the wider use of the ultrasonic aspirator in laparoscopic liver surgery, hydro-jet and ultrasonic surgical aspirators have shown similar efficacy and safety for transection of the liver parenchyma during laparoscopic resection.

Dynamic mapping using an electrified ultrasonic aspirator in lipomyelomeningocele and spinal cord detethering surgery-a feasibility study.

Intraoperative neurophysiologic monitoring (IONM) is an established technique and adjunct of brain and spinal lesion resection surgery. In spina bifida syndrome surgery, mapping of the surgical wound is a common and accepted method in determining the position and functionality of nerve roots of the cauda equina (CE), especially when the anatomy is not straightforward and roots are splayed across or entangled within the lesion. Here, we describe a novel technique of continuous CE mapping using an electrified cavitron ultrasonic aspirator (eCUSA) in children with lipomyelomeningocele (LMMC) lesions. We assessed a method of dynamic CE mapping using an eCUSA as a stimulation probe. Twenty children (0.5-18 years) were included in this study, diagnosed with occult spina bifida LMMC in which the eCUSA stimulator was applied. IONM data and 2-weeks post-operative data were collected. LMMC lesions were located in the lumbar, sacral, and lumbosacral spine. eCUSA stimulation at 0.3-3.0 mA intensities elicited positive lower extremity muscle responses in 12 of the 20 patients included in the study. These responses allowed the surgeon real-time identification of the nerve roots tangent at the LMMC-cauda equina structure and intensive removal of the fat tissue in the area non-responding to the eCUSA stimulation. Continuous eCUSA-based stimulation of the cauda equina during LMMC resection is a feasible mapping technique with potential added value improving safety of untethering. Future studies evaluating extension of untethering, as well as the rates of retethering and long-term neurological and urological outcomes, are warranted.

Introduction of a novel connection clip for the ultrasonic aspirator for subcortical continuous motor mapping

IntroductionA connection clip to the ultrasonic aspirator handpiece was introduced for simultaneous resection and mapping of corticospinal motor tract (CST) (Kombos et al., 2001).Research questionTo report retrospectively the use of this clip in cerebral surgery with CST mapping.Material and methodsEight women and four men were included (mean: 55.8 years, SD 17.3 years). The ultrasonic aspirator handpiece was stimulated every second (5 biphasic pulses, 0.4 ​ms per phase, max 14 ​mA). Motor evoked potentials (MEPs) (Taniguchi et al., 1993), with transcranial and direct cortical stimulation, were alternated with CST mapping. The distances between the stimulus locations to the CST (diffusion tensor imaging based fibre tractography) were determined postoperatively. Muscle strength was evaluated pre-operatively, at discharge and 3 months.ResultsMotor mapping thresholds ranged between 2 and 13 ​mA, in 12 consecutive patients (7 post-central, 5 insular). The distance of the stimulation site to the CST was fitted (y ​= ​0.63x+2.33, R2 ​= ​0.33; x, mA; y, mm), approximating the rule of thumb of 1 ​mA indicating 1 ​mm (R2 ​= ​0.22). One patient presented with a deterioration of motor function (wrist, M4+). No intraoperative seizures were observed.DiscussionThe concept that 1 ​mA corresponds to 1 ​mm from the CST, was roughly observed within this low current range. This rule must be applied, integrating the confidence limits, when getting close to the CST, in conjunction with MEPs.ConclusionThe standardization of this clip, for continuous stimulation of the ultrasonic aspirator with simultaneous tissue resection, made the guided surgical flow smoother, more refined and very natural.

A 270-Degree Decompression of Optic Nerve in Refractory Idiopathic Intracranial Hypertension Using an Ultrasonic Aspirator - A Prospective Institutional Study.

Although the nonsurgical treatment for idiopathic intracranial hypertension (IIH) involves weight loss, diuretics, and steroids, surgical intervention is required if there is a worsening of symptoms or visual deterioration. To determine the efficacy and complications of transcranial optic nerve sheath fenestration (ONSF) using an ultrasonic aspirator as an adjunct in the treatment of refractory IIH. This prospective study included all patients with medically refractory IIH with visual deterioration from November 2017 to June 2019. Pterional craniotomy was followed by extradural clinoidectomy and optic foramen bony decompression using an ultrasonic aspirator. All the cases were followed up for changes in visual acuity and field and surgical outcomes. A total of 21 consecutive patients who underwent ONSF in the study period were included for analysis. Improvement in visual acuity was noted in 19/21 (90.47%) patients. Improvement in visual fields was noted in 17/21 (80.95%). Headache improved in 66.67% of patients. Improvement in the fundus picture was noted in 90.47%. Symptoms < 6 months showed better results compared to > 6 months symptom, although statistically nonsignificant (P = 0.2556). A 270-degree optic canal decompression was achieved in all the cases. Transcranial optic nerve sheath decompression with a bone ultrasonic aspirator is a safe and direct decompression of the optic nerve in malignant/refractory cases of IIH.

Factors Affecting Surgical Outcome of Intramedullary Spinal Cord Tumors: A Prospective One-year Follow-Up Study

Background Data: Identification of the prognostic factors of the surgical outcomes of intramedullary spinal cord tumors (IMSCTs) is essential. Many studies have established that early surgical intervention was associated with better outcomes and enhanced survival rates. Purpose: This study investigated the prognostic factors of the one-year surgical outcomes of patients with IMSCTs. Study Design: A prospective clinical case study. Patients and Methods: Twenty patients with IMSCTs, who underwent surgery in our institution and were followed up at our clinic were recruited for this study. Patients were followed up for one year to assess postoperative functional outcomes using the modified McCormick Scale (MMS). The reported parameters included preoperative MMS, use of operative monitoring, use of ultrasonic aspirator, the extent of tumor resection, and postoperative adjuvant therapy. Results: Operatively, 85% of patients underwent laminectomy, 55% reported growth total resection (GTR), 55% intraoperative monitoring, 75% underwent ultrasonic aspiration, 55% had syrinx, and 20% had duraplasty. The preoperative MMS improved from 3.0 to 2.32 and 2.42 postoperatively at six months and one year of follow-up, respectively. Patients with postoperative MMS ≤3 were more likely to undergo GTR with better postoperative MMS than those with preoperative MMS >3 at six-month follow-up (81.8% vs. 25%, respectively; p = 0.013) and at one-year follow-up (84.4 vs. 0%, respectively; p = 0.001). Good preoperative MMS, use of ultrasonic aspirator, and operative monitoring were associated with better MMS. There were no significant associations between MMS at the sixth month and reported parameters including gender, symptoms duration, tumor location, bony work whether laminectomy or laminoplasty, number of segments involved, tumor histopathology, duraplasty, and postoperative adjuvant therapy. Conclusion: The findings of the current study showed that patients with GTR, good preoperative MMS, intraoperative monitoring, and ultrasonic aspirator usage might be associated with better functional outcomes. (2021ESJ229)

A Single Center Prospective Randomized Study for Comparison of Water Jet Dissector and Ultrasonic Aspirator in the Division of the Liver Parenchyma during Laparoscopic Resection

Introduction: To date, there are no prospective randomized studies that have studied the safest and most feasible method of liver parenchyma transection in laparoscopic liver resection (LRR).We aimed to compare the short-term Results of two methods of liver parenchyma transection during LLR in a prospective, randomized trial.