Ultrasonic bone curette-assisted unilateral approach for bilateral decompression with MIS-TLIF for severe lumbar spinal stenosis.

PURPOSE: We aimed to evaluate the clinical efficacy of bilateral decompression with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) assisted by an ultrasonic bone curette (UBC) for treating severe degenerative lumbar spinal stenosis (DLSS) and traditional tool laminectomy decompression MIS-TLIF for treating severe DLSS. METHODS: The clinical data of 128 patients with single-segment severe DLSS who were admitted between January 2017 and December 2021 were retrospectively analyzed. Among them, 67 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using an ultrasonic bone curette (UBC group), whereas 61 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using traditional tools (traditional group, control). A visual analog scale (VAS) was used to evaluate back and lower limb pain before the operation,immediate postoperative, and one week, 3, 6, 12, and 24 months after the operation. Oswestry disability index (ODI) and Zurich claudication score (ZCQ) were employed to evaluate the improvement in low back and lower limb function. At the last follow-up, the Bridwell bone graft fusion standard was utilized to evaluate bone graft fusion. RESULTS: The decompression time of laminectomy was significantly shorter in the UBC group than in the traditional group (control group), and the intraoperative blood loss and postoperative drainage volume were significantly less in those in the control group (P < 0.05). The VAS, ODI, and ZCQ scores of the two groups after the operation were significantly improved compared to those before the operation (P < 0.05). The UBC group had better VAS back scores than the control group immediate postoperative and one week after the operation(P < 0.05). The UBC group had better VAS lower limb scores than the control group immediate postoperative (P < 0.05).The incidence of perioperative complications, hospitalization time, dural sac cross-sectional area (CSA), and dural sac CSA improvement rate did not differ significantly between the two groups (P > 0.05). VAS and ODI scores did not differ significantly between the two groups before,three, six months, one year, and two years after surgery (P > 0.05). The ZCQ scores did not differ significantly between the two groups before the operation at one week, six months, one year, and two years after the operation (P > 0.05). According to the Bridwell bone graft fusion standard, bone graft fusion did not occur significantly between the two groups (P > 0.05) at the last follow-up. CONCLUSIONS: UBC unilateral fenestration bilateral decompression MIS-TLIF in treating severe DLSS can achieve clinical efficacy as traditional tool unilateral fenestration bilateral decompression MIS-TLIF and reduce intraoperative blood loss and postoperative drainage. It can also shorten the operation time, effectively reduce the work intensity of the operator, and reduce the degree of low back pain during short-term follow-ups. Therefore, this is a safe and effective surgical method.

Improvement in Intraoperative Image Quality in Transcranial Magnetic Resonance-Guided Focused Ultrasound Surgery Using Transmitter Gain Adjustment.

INTRODUCTION: Transcranial magnetic resonance-guided focused ultrasound surgery (TcMRgFUS) has the advantage of allowing immediate evaluation of therapeutic effects after each sonication and intraoperative magnetic resonance imaging (MRI) to visualize the lesion. When the image shows that the lesion has missed the planned target and the therapeutic effects are insufficient, the target of the subsequent ablation can be finely adjusted based on the image. The precision of this adjustment is determined by the image quality. However, the current intraoperative image quality with a 3.0T MRI system is insufficient for precisely detecting the lesion. Thus, we developed and validated a method for improving intraoperative image quality. METHODS: Because intraoperative image quality is affected by transmitter gain (TG), we acquired T2-weighted images (T2WIs) with two types of TG: the automatically adjusted TG (auto TG) and the manually adjusted TG (manual TG). To evaluate the character of images with 2 TGs, the actual flip angle (FA), the image uniformity, and the signal-to-noise ratio (SNR) were measured using a phantom. Then, to assess the quality of intraoperative images, T2WIs with both TGs were acquired during TcMRgFUS for 5 patients. The contrast-to-noise ratio (CNR) of the lesion was retrospectively estimated. RESULTS: The images of the phantom with the auto TG showed substantial variations between the preset and actual FAs (p < 0.01), whereas on the images with the manual TG, there were no variations between the two FAs (p > 0.05). The total image uniformity was considerably lower with the manual TG than with the auto TG (p < 0.01), indicating that the image's signal values with the manual TG were more uniform. The manual TG produced significantly higher SNRs than the auto TG (p < 0.01). In the clinical study, the lesions were clearly detected in intraoperative images with the manual TG, but they were difficult to identify in images with the auto TG. The CNR of lesions in images with manual TG was considerably higher than in images with auto TG (p < 0.01). CONCLUSION: Regarding intraoperative T2WIs using a 3.0T MRI system during TcMRgFUS, the manual TG method improved image quality and delineated the ablative lesion more clearly than the current method with auto TG.

Anatomical Phase Extraction (APE) Method: A Novel Method to Correct Detrimental Effects of Tissue-Inhomogeneity in Referenceless MR Thermometry-Preliminary Ex Vivo Investigation.

PURPOSE: We present a novel background tissue phase removing method, called anatomical phase extraction (APE), and to investigate the accuracy of temperature estimation and capability of reducing background artifacts compared with the conventional referenceless methods. METHODS: Susceptibility variance was acquired by subtracting pretreatment baseline images taken at different locations (nine pretreatment baselines are acquired and called φ 1 to φ 9). The susceptibility phase data φ S was obtained using the Wiener deconvolution algorithm. The background phase data φ T was isolated by subtracting φ S from the whole phase data. Finally, φ T was subtracted from the whole phase data before applying the referenceless method. As a proof of concept, the proposed APE method was performed on ex vivo pork tenderloin and compared with other two referenceless temperature estimation approaches, including reweighted ℓ1 referenceless (RW- ℓ1) and ℓ2 referenceless methods. The proposed APE method was performed with four different baselines combination, namely, (φ 1, φ 5, φ 2, φ 4), (φ 3, φ 5, φ 2, φ 6), (φ 7, φ 5, φ 8, φ 4), and (φ 9, φ 5, φ 8, φ 6), and called APE experiment 1 to 4, respectively. The multibaseline method was used as a standard reference. The mean absolute error (MAE) and two-sample t-test analysis in temperature estimation of three regions of interest (ROI) between the multibaseline method and the other three methods, i.e., APE, RW- ℓ1, and ℓ2, were calculated and compared. RESULTS: Our results show that the mean temperature errors of the APE method-experiment 1, APE method-experiment 2, APE method-experiment 3, APE method-experiment 4, and RW- ℓ1 and ℓ2 referenceless method are 1.02°C, 1.04°C, 1.00°C, 1.00°C, 4.75°C, and 13.65°C, respectively. The MAEs of the RW- ℓ1 and ℓ2 referenceless methods were higher than that of APE method. The APE method showed no significant difference (p > 0.05), compared with the multibaseline method. CONCLUSION: The present work demonstrates the use of the APE method on referenceless MR thermometry to improve the accuracy of temperature estimation during MRI guided high-intensity focused ultrasound for ablation treatment.

Potential optimization of focused ultrasound capsulotomy for obsessive compulsive disorder.

Obsessive-compulsive disorder is a debilitating and often refractory psychiatric disorder. Magnetic resonance-guided focused ultrasound is a novel, minimally invasive neuromodulatory technique that has shown promise in treating this condition. We investigated the relationship between lesion location and long-term outcome in patients with obsessive-compulsive disorder treated with focused ultrasound to discern the optimal lesion location and elucidate the efficacious network underlying symptom alleviation. Postoperative images of 11 patients who underwent focused ultrasound capsulotomy were used to correlate lesion characteristics with symptom improvement at 1-year follow-up. Normative resting-state functional MRI and normative diffusion MRI-based tractography analyses were used to determine the networks associated with successful lesions. Patients with obsessive-compulsive disorder treated with inferior thalamic peduncle deep brain stimulation (n = 5) and lesions from the literature implicated in obsessive-compulsive disorder (n = 18) were used for external validation. Successful long-term relief of obsessive-compulsive disorder was associated with lesions that included a specific area in the dorsal anterior limb of the internal capsule. Normative resting-state functional MRI analysis showed that lesion engagement of areas 24 and 46 was significantly associated with clinical outcomes (R = 0.79, P = 0.004). The key role of areas 24 and 46 was confirmed by (i) normative diffusion MRI-based tractography analysis, showing that streamlines associated with better outcome projected to these areas; (ii) association of these areas with outcomes in patients receiving inferior thalamic peduncle deep brain stimulation (R = 0.83, P = 0.003); and (iii) the connectedness of these areas to obsessive-compulsive disorder-causing lesions, as identified using literature-based lesion network mapping. These results provide considerations for target improvement, outlining the specific area of the internal capsule critical for successful magnetic resonance-guided focused ultrasound outcome and demonstrating that discrete frontal areas are involved in symptom relief. This could help refine focused ultrasound treatment for obsessive-compulsive disorder and provide a network-based rationale for potential alternative targets.

Ultrasound renal denervation for hypertension resistant to a triple medication pill (RADIANCE-HTN TRIO): a randomised, multicentre, single-blind, sham-controlled trial.

BACKGROUND: Endovascular renal denervation reduces blood pressure in patients with mild-to-moderate hypertension, but its efficacy in patients with true resistant hypertension has not been shown. We aimed to assess the efficacy and safety of endovascular ultrasound renal denervation in patients with hypertension resistant to three or more antihypertensive medications. METHODS: In a randomised, international, multicentre, single-blind, sham-controlled trial done at 28 tertiary centres in the USA and 25 in Europe, we included patients aged 18-75 years with office blood pressure of at least 140/90 mm Hg despite three or more antihypertensive medications including a diuretic. Eligible patients were switched to a once daily, fixed-dose, single-pill combination of a calcium channel blocker, an angiotensin receptor blocker, and a thiazide diuretic. After 4 weeks of standardised therapy, patients with daytime ambulatory blood pressure of at least 135/85 mm Hg were randomly assigned (1:1) by computer (stratified by centres) to ultrasound renal denervation or a sham procedure. Patients and outcome assessors were masked to randomisation. Addition of antihypertensive medications was allowed if specified blood pressure thresholds were exceeded. The primary endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Safety was also assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02649426. FINDINGS: Between March 11, 2016, and March 13, 2020, 989 participants were enrolled and 136 were randomly assigned to renal denervation (n=69) or a sham procedure (n=67). Full adherence to the combination medications at 2 months among patients with urine samples was similar in both groups (42 [82%] of 51 in the renal denervation group vs 47 [82%] of 57 in the sham procedure group; p=0·99). Renal denervation reduced daytime ambulatory systolic blood pressure more than the sham procedure (-8·0 mm Hg [IQR -16·4 to 0·0] vs -3·0 mm Hg [-10·3 to 1·8]; median between-group difference -4·5 mm Hg [95% CI -8·5 to -0·3]; adjusted p=0·022); the median between-group difference was -5·8 mm Hg (95% CI -9·7 to -1·6; adjusted p=0·0051) among patients with complete ambulatory blood pressure data. There were no differences in safety outcomes between the two groups. INTERPRETATION: Compared with a sham procedure, ultrasound renal denervation reduced blood pressure at 2 months in patients with hypertension resistant to a standardised triple combination pill. If the blood pressure lowering effect and safety of renal denervation are maintained in the long term, renal denervation might be an alternative to the addition of further antihypertensive medications in patients with resistant hypertension. FUNDING: ReCor Medical.

TWENTY-THREE-GAUGE HYPERSONIC VITRECTOMY: Real-World Surgical Evidence.

PURPOSE: To evaluate the safety, effectiveness, and the best parameters setup of hypersonic vitrectomy. METHODS: A prospective, multicentric, interventional study on 50 eyes that had undergone hypersonic vitrectomy because of various vitreoretinal diseases. We primarily assessed the effectiveness of vitreous removal, intraoperative complications, and surgical setup. Secondarily, we evaluated single-surgery anatomical success and postoperative best-corrected visual acuity. RESULTS: Intraoperative complications occurred in 5 eyes (10%), whereas technical problems were detected in 23 eyes (46%), resulting in conversion to guillotine vitrectomy in 15 cases. The most common finding related to the technical problems was an inadequate vitreous liquefaction with the formation of vitreous strands and consequent inadequate vitreous outflow, sometimes complicated by vitreous incarceration in the vitrectomy probe. The best settings were considered a stroke of 60 µm and vacuum of 40 mmHg for both core and peripheral vitrectomy. At 3-month follow-up, primary anatomical success was achieved in 49 eyes (98%) and the mean best-corrected visual acuity overall improved. CONCLUSION: The availability of hypersonic vitrectomy in the current surgical practice opens a new era in vitreoretinal surgery. Despite the potential advantages in fluidics, the performance of hypersonic vitrectomy system needs to be further optimized, mainly for the occurrence of inadequate vitreous liquefaction and vitreous strands formation.

Cavitron ultrasonic surgical aspirator for mitral annular decalcification.

Mitral valve surgery can be especially difficult in patients with mitral annular calcification. Not only is it associated with higher morbidity and mortality, but there is no consensus strategy for the treatment of mitral annular calcification, which may render some patients inoperable. We describe a case of severe mitral annular calcification successfully treated with the cavitron ultrasonic surgical aspirator.   We demonstrate the proper technique for and the efficacy of using this instrument for decalcification of the mitral annulus. The video tutorial includes the patient presentation, preoperative and postoperative imaging, and the proper surgical technique for cavitron ultrasonic surgical aspirator-assisted mitral annular decalcification. With the proper technique, the cavitron ultrasonic surgical aspirator may mitigate the risk of surgical complications associated with severe calcification of the mitral annulus.

Periodontal evaluation of palatally impacted maxillary canines treated by closed approach with ultrasonic surgery and orthodontic treatment: a retrospective pilot study.

Aim of this study is the evaluation of the periodontal status of impacted canines treated by closed approach with ultrasonic surgery and orthodontic treatment compared with contralateral spontaneously erupted teeth. The periodontal conditions of the teeth adjacent to the canines (lateral incisors and first premolar) were also considered. 17 patients (9 females and 8 males; mean age: 15.2 years) with unilateral palatal impaction of maxillary canine were selected. All patients were treated by closed-flap surgery with ultrasonic instruments. Periodontal status was evaluated by assessing probing depth (PD), gingival recession and width of keratinized tissue (KT) 4.6 months after the end of the orthodontic treatment, on average. Test group was composed by impacted elements and adjacent teeth and control group by contralateral spontaneously erupted canines and adjacent teeth. Student's t-test was used to compare test and control group values of PD and width of KT. Significance threshold for Student's t-test was set at p < 0.05. The average probing depth values show no significant clinical differences between the test and control groups. Probing depths recorded at the mesiovestibular and distopalatal sides of the impacted canine were statistically significant compared to the control elements (p < 0.05). No gingival recession was detected on the treated canines. The measurement of KT did not differ significantly between the test and the control groups. In conclusion, the ultrasonic surgery for disinclusion associated with a closed approach and orthodontic traction allows the alignment of an impacted palatal canine without damaging the periodontium.

Endoscopic ultrasonic aspiration of an intraparenchymal hematoma in a newborn.

Neonatal intracerebral hemorrhage is associated with substantial morbidity and mortality. Treatment is largely conservative, though interventions to evacuate intraventricular and intraparenchymal hematomas (IPHs) have been applied. Endoscopic ultrasonic aspiration for the treatment of IPH has increasingly been shown to be a useful strategy in adults; however, it has not been studied in children, and the technology has been more commonly applied to intraventricular hemorrhage (IVH). Here, the authors describe, to the best of their knowledge, the first use of endoscopic ultrasonic aspiration for IPH in a newborn.An 8-week-old female presented with IPH secondary to left M3 aneurysm rupture, which was treated with coil embolization for aneurysm securement and vessel sacrifice, followed by IPH evacuation using endoscopic ultrasonic aspiration. Through applying this approach in a newborn, the authors gained technical insight not previously reported in the application of this technique in similar cases in adults or in cases of IVH. They highlight this case to share learning points and technical challenges regarding the application of endoscopic ultrasonic aspiration in a newborn along with learning points for imaging and visualization. Endoscopic ultrasonic aspiration can be used to treat IPH in select newborns. Further study is needed to improve efficacy and ease when applying this approach in very young patients.

Ultrasonic osteotome versus high-speed burr in cervical anterior vertebral subtotal resection: A retrospective study of 81 cases.

AIM: This study aimed to investigate the safety and effectiveness of ultrasonic osteotome in cervical anterior vertebral subtotal resection. METHODS: Retrospective clinical data were collated for 81 patients with cervical spondylotic myelopathy who required cervical anterior vertebral subtotal resection. RESULTS: Group A (n=40) was treated with an ultrasonic osteotome and group B (n=41) with a high-speed burr. Vertebrectomy time, intraoperative blood loss, surgical complications, Japanese Orthopedic Association (JOA) scores and JOA score improvement were compared. Group A showed significantly shorter vertebrectomy time and significantly less intraoperative blood loss (P<0.05). In group A, dysphagia occurred in one patient, and superior laryngeal nerve injury in one. Urinary tract infection occurred in one patient in group B. JOA score in both groups significantly increased 3 days after surgery (P<0.05), and at last follow-up compared with 3 days after surgery (P<0.05). CONCLUSION: Ultrasonic osteotome was a safe and effective tool for subtotal anterior cervical vertebral resection.

Ultrasonic bone scalpel for thoracic spinal decompression: case series and technical note.

BACKGROUND: Thoracic spinal stenosis (TSS) is a rare but intractable disease that fails to respond to conservative treatment. Thoracic spinal decompression, which is traditionally performed using high-speed drills and Kerrison rongeurs, is a time-consuming and technically challenging task. Unfavorable outcomes and high incidence of complications are the major concerns. The development and adaptation of ultrasonic bone scalpel (UBS) have promoted its application in various spinal operations, but its application and standard operating procedure in thoracic decompression have not been fully clarified. Therefore, the purpose of this study is to describe our experience and technique note of using UBS and come up with a standard surgical procedure for thoracic spinal decompression. METHODS: A consecutive of 28 patients with TSS who underwent posterior thoracic spinal decompression surgery with UBS between December 2014 and May 2015 was enrolled in this study. The demographic data, perioperative complications, operation time, estimated blood loss, and pre- and postoperative neurological statuses were recorded and analyzed. Neurological status was evaluated with a modified Japanese Orthopaedic Association (JOA) scale, and the neurological recovery rate was calculated using the Hirabayashi's Method. RESULTS: Thoracic spinal decompression surgery was successfully carried out in all cases via a single posterior approach. The average age at surgery was 49.7 ± 8.5 years. The mean operative time of single-segment laminectomy was 3.0 ± 1.4 min, and the blood loss was 108.3 ± 47.3 ml. In circumferential decompression, the average blood loss was 513.8 ± 217.0 ml. Two cases of instrument-related nerve root injury occurred during operation and were cured by conservative treatment. Six patients experienced cerebrospinal fluid (CSF) leakage postoperatively, but no related complications were observed. The mean follow-up period was 39.7 ± 8.9 months, the average JOA score increased from 4.7 before surgery to 10.1 postoperatively, and the average recovery rate was 85.8%. CONCLUSIONS: The UBS is an optimal instrument for thoracic spinal decompression, and its application enables surgeons to decompress the thoracic spinal cord safely and effectively. This standard operating procedure is expected to help achieve favorable outcomes and can be used to treat various pathologies leading to TSS.

Transforming laparoendoscopic surgical protocols during the COVID-19 pandemic; big data analytics, resource allocation and operational considerations.

The current dreadful pandemic of coronavirus disease (COVID-19) is playing havoc with humanity, socio-communal systems and economic reserves worldwide. Certain countries have managed to curtail COVID-19 crisis to some extent, however, a great majority still remains helpless in containing this outbreak. Rapidly evolving disease patterns and complex epidemiology of the COVID-19 necessitate a tailored approach by medical experts in dealing with this devastating outbreak. Similar to other medical disciplines, surgical associations and societies have developed a tailored approach of patients' selection and management plans with improvised endolaparoscopic practice during the COVID-19 pandemic. Non-essential and non-urgent surgical procedures are deferred till this outbreak is abated. Benefits of delaying elective and non-urgent surgery outweighs the risk of performing surgical procedures on patients with asymptomatic or active COVID-19 disease. Laparoendoscopic procedures increase the risk of aerosol exposure, disease transmission and contamination. Limiting the number of operating room personnel, use of disposable instruments, small trocar incisions, negative pressure environment, and setting energy devices at low modes can help reduce disease transmission during laparoendocsopic procedures. This write up sheds lights on the impact of the COVID-19, big data analytics of response of medical personnel in understanding and curtailing the disease process and the consensus guidelines for carrying out laparoscoendoscopic procedures.

The Influence of Ultrasound Ciliary Plasty on Corneal Parameters.

PRéCIS:: The ultrasound ciliary plasty (UCP) procedure affects corneal parameters, although the effect is transient. Ultrasound energy affects the sclera, leading to induced astigmatism. The area of energy application correlates with the astigmatism axis. PURPOSE: To assess the postoperative corneal topography for 1 year after UCP. MATERIALS AND METHODS: In total, 78 patients with primary and secondary refractory glaucoma were enrolled in the study. The primary outcome measures were the corneal parameters obtained with anterior segment swept-source optical coherence tomography. Intraocular pressure, number of antiglaucoma medications, and best-corrected logMAR visual acuities were analyzed as secondary outcome measures. Measurements were performed preoperatively and at 1 week, and 1, 3, 6, and 12 months postoperatively. A total of 39 patients (39 eyes) completed the follow-up period of 12 months. RESULTS: There was a significant difference in the anterior/posterior steep/flat keratometry and anterior/posterior astigmatism values immediately after UCP. However, 3 months postoperatively these parameters returned to their initial values and there were no significant differences noted. The mean±SD values of anterior astigmatism preoperatively and at 1 week, and 1, 3, 6, and 12 months postoperatively were 1.12±0.66 D, 2.17±0.91 D (P<0.001), 2.05±0.93 D (P<0.001), 1.55±0.75 D (P=0.004), 1.31±0.70 D (P=0.024), and 1.20±0.73 D (P=0.406), respectively. The astigmatism axis tended to approach 90 degrees meridian with a significant difference 1 week postoperatively. Central and minimal corneal thickness remained unchanged, whereas the intraocular pressure and the number of antiglaucoma medications decreased significantly. CONCLUSIONS: UCP influenced the corneal topography parameters in the immediate postoperative period; however, with time, all parameters returned to their initial values.

Salvage open radical prostatectomy for recurrent prostate cancer following MRI-guided transurethral ultrasound ablation (TULSA) of the prostate: feasibility and efficacy.

Introduction: MRI-guided transurethral ultrasound ablation (TULSA) is a novel modality for minimally invasive ablation in patients with localised prostate cancer (PCa). A multi-national Phase 1 (30 patients) and subsequent Phase 2 (115 patients) study showed TULSA to be feasible, safe and well tolerated. However, technical viability and safety of salvage prostatectomy for those who failed TULSA is unclear. Herein, we report the feasibility and morbidity of salvage radical prostatectomy (sRP) post-TULSA.Methods: Four patients with biopsy-proven residual cancer following TULSA underwent open retropubic sRP within 39 months of TULSA. Peri-and post-operative morbidity were reported. Detailed histopathologic assessment is reported.Results: Median follow-up was 43 months after sRP. Mean operating times, blood loss, and length of stay were 210 min, 866 ml, and 3.5 days, respectively. Intraoperative finding of some fibrotic reaction of endopelvic and Denonvilliers fascia was characteristic. There were no perioperative complications. Whole-mount pathology sections showed one pT2b and three pT3a, suggesting under-staging pre-TULSA. Location of disease was compatible with persistent cancer mostly in the untreated peripheral safety region. One man received an artificial urinary sphincter. All men experienced erectile dysfunction responsive to treatment. Two patients with positive surgical margins had PSA progression requiring salvage radiation, with one requiring long-term androgen deprivation therapy.Conclusions: RP is a viable and safe salvage option if TULSA fails. Technical difficulty and perioperative morbidity were negligible and attributable to minimal peri-prostatic reaction from TULSA.

Predicting final lesion characteristics during MR-guided focused ultrasound pallidotomy for treatment of Parkinson's disease.

OBJECTIVE: Magnetic resonance-guided focused ultrasound (MRgFUS) ablation of the globus pallidus interna (GPi) is being investigated for the treatment of advanced Parkinson's disease symptoms. However, GPi lesioning presents unique challenges due to the off-midline location of the target. Furthermore, it remains uncertain whether intraprocedural MR thermometry data can predict final lesion characteristics. METHODS: The authors first performed temperature simulations of GPi pallidotomy and compared the results with those of actual cases and the results of ventral intermediate nucleus (VIM) thalamotomy performed for essential tremor treatment. Next, thermometry data from 13 MRgFUS pallidotomy procedures performed at their institution were analyzed using 46°C, 48°C, 50°C, and 52°C temperature thresholds. The resulting thermal models were compared with resulting GPi lesions noted on postprocedure days 1 and 30. Finally, the treatment efficiency (energy per temperature rise) of pallidotomy was evaluated. RESULTS: The authors' modeled acoustic intensity maps correctly demonstrate the elongated, ellipsoid lesions noted during GPi pallidotomy. In treated patients, the 48°C temperature threshold maps most accurately predicted postprocedure day 1 lesion size, while no correlation was found for day 30 lesions. The average energy/temperature rise of pallidotomy was higher (612 J/°C) than what had been noted for VIM thalamotomy and varied with the patients' skull density ratios (SDRs). CONCLUSIONS: The authors' acoustic simulations accurately depicted the characteristics of thermal lesions encountered following MRgFUS pallidotomy. MR thermometry data can predict postprocedure day 1 GPi lesion characteristics using a 48°C threshold model. Finally, the lower treatment efficiency of pallidotomy may make GPi lesioning challenging in patients with a low SDR.

Ovarian tissue health after laparoscopic unilateral oophorectomy: A porcine model for establishing optimized fertility preservation techniques in children.

BACKGROUND: The only pre-treatment fertility preservation option for prepubertal girls, who are at risk for infertility due to their diagnosis or treatment, is surgical removal of ovarian tissue for cryopreservation (OTC). We investigated ovarian tissue health following isolation with an ultrasonic advanced energy device (UAED), that has a previously reported thermal spread of ≤2 cm. METHODS: The ovaries of eight Yucatan minipigs were isolated by laparoscopy (1) close dissection with the UAED located up to 2 mm away from the ovarian capsule, (2) far dissection with the UAED located >2 cm away, or by (3) laparotomy for control ovaries using cold scissors. Ovarian cortex tissues were cultured for 4 days to assess tissue health. RESULTS: Ovarian cortex tissue isolated using a UAED produced an altered metabolic ratio in both the far and close dissection compared to control (p < 0.001). There was an increase in folliculogenesis in the control samples over samples isolated with far and close dissection (p < 0.0001), and a reduction in estradiol production in experimental groups (p < 0.0001). CONCLUSIONS: This model defines differences in ovarian tissue health among different isolation techniques. Ongoing work will further define the standard of care surgical technique for OTC.

3D Real-Time Image-Guided Navigation Spine Corpectomy with Ultrasonic Bone Cutter: Technical Note.

BACKGROUND: Surgical interventions for congenital scoliosis are challenging for spine surgeons. The coordination of 3-dimensional (3D), real-time, image-guided navigation with an ultrasonic bone cutter allows surgeons to localize the affected area of the spine accurately and remove the lesion without damaging soft tissue structures. The goal of this technical paper is to report a previously undescribed method of hemivertebrectomy that combines 3D, real-time, image-guided navigation and an ultrasonic bone cutter. We highlight the feasibility and safety of this method in spinal surgery. METHODS: Three patients with congenital scoliosis were treated with this technique. We present three illustrative cases comprising hemivertebrectomies for congenital scoliosis. Intraoperative photos demonstrating the technique are also provided. RESULTS: All surgeries were completed without complications. The hemivertebrae were completely removed, and marked correction of congenital scoliosis was noted. CONCLUSIONS: We believe that the combination of 3D, real-time image navigation and an ultrasonic bone cutter improves hemivertebrectomy by increasing accuracy and avoiding dura laceration, major organ damage, or potential vessel damage.

Update review of pain control methods of tonsil surgery.

Pain after tonsil surgery is troublesome because it causes discomfort. In addition, handling patients with postoperative pain is challenging to otolaryngologists. Many laboratory studies have assessed the use of analgesics and surgical techniques to discover methods for effective control of postoperative pain associated with tonsil surgery. In this review article, we summarize and provide a comprehensive overview of current methods for the control of pain after tonsil surgery based on findings of recent studies. Although powered intracapsular tonsillotomy is not popular yet, it seems to be an effective option among various surgical techniques. More discussion about powered intracapsular tonsillotomy should be done in the future. On the other hand, surgery with a harmonic scalpel, fibrin glue, or cryoanalgesia seems ineffective. When reviewing medical treatment methods, the use of nonsteroidal anti-inflammatory drugs, steroids, and/or gabapentin/pregabalin seems to be effective. However, the use of opioid (especially codeine) for children should be avoided because of possible respiratory insufficiency. Ketorolac is dangerous because of the risk of hemorrhage. We should continue to focus on the development of novel postoperative pain control techniques with no or low complications.

ULTRASOUND IN VITRECTOMY: An Alternative Approach to Traditional Vitrectomy Techniques.

PURPOSE: To study a prototype of an ultrasound-based vitrector, and to try to understand the physical phenomena underlying this new technology. METHODS: We tested the ultrasound-based vitrector prototype (UV) (ultrasonically-driven handpiece obtained from a modified version of the Alcon CONSTELLATION Vision System [Alcon]) using an automatic experimental setup. Balanced saline solution (BSS) and vitreous (from fresh postmortem enucleated porcine eyes) flow rates were analyzed using three different tips. RESULTS: In general, BSS solution flow rates increased with increasing aspiration levels and decreased when we used % US power. Vitreous flow rates were influenced by aspiration levels, % US power, and ultrasound-related phenomena: cavitation phenomenon and "jet streaming." CONCLUSION: Ultrasound-based vitrectomy may represent an important alternative to traditional vitrectomy. Such a tool, capable of liquefying and excising the vitreous body using ultrasound, could overcome all the limits of the guillotine-based technique (GV). Knowledge of the physical phenomena underlying ultrasound-based technology is a necessary prerequisite for further development of this new technology.

Efficacy and Safety Analysis of Ultrasonic Bone Curette in the Treatment of Thoracic Spinal Stenosis.

OBJECTIVE: To investigate the efficacy and safety of ultrasonic bone curette in treating thoracic spinal stenosis. METHODS: A total of 30 patients of thoracic spinal stenosis who underwent posterior thoracic decompression in the hospital from December 2015 to 2017 were enrolled. Of these, 18 patients (group A) underwent posterior thoracic decompression using ultrasonic bone curette; and 12 patients underwent the treatment using a high-speed drill (group B). The time of laminectomy, amount of intraoperative blood loss, presence or absence of cerebrospinal fluid leakage, and nerve root injury were recorded. All patients underwent X-ray, computed tomography with three-dimensional reconstruction, and magnetic resonance imaging before and after surgery. The Frankel classification and the Japanese Orthopaedic Association (JOA) scores were used to assess the neurological function and neurological recovery in patients. The measured data were statistically processed and analyzed using SPSS21.0 software, and the measurement data were expressed as mean ± SD. RESULTS: In groups A and B, the average time for single-segment laminectomy was 3.3 ± 1.2 min and 6.0 ± 1.8 min and the mean bleeding volume was 105.5 ± 43.3 mL and 177.4 ± 54.7 mL, respectively, with a statistically significant difference between the groups. The difference in JOA scores before and after surgery in groups A and B was statistically significant. No significant difference was found between the groups, in group A, the improvement rate of nerve function at the last follow-up was 71% and in group B, the improvement rate at the last follow-up was 70%. In group A, at last follow-up, two patients had Frankel grade B injury, one had grade C injury, seven had grade D injury, and eight had grade E injury. In group B, at last follow-up, one patient had Frankel grade B injury, one had grade C injury, five had grade D injury, and five had grade E injury. The Frankel classification of both groups A and B significantly improved. Four patients experienced cerebrospinal fluid leakage in group A and five in group B, with no significant difference between the groups. There was no nerve root injury in both groups, and no complications, such as pulmonary infection and urinary tract infection, occurred after operation. CONCLUSIONS: With the use of ultrasonic bone curette in posterior thoracic decompression, the decompression surgery could be completed relatively safely and quickly. It effectively reduced the amount of intraoperative blood loss.