Investigating surgical smoke in otolaryngology operating rooms.

Surgical smoke is a common chemical hazard produced from the use of electrocautery, laser, or ultrasonic scalpels during surgery. It has been proved harmful to medical personnel. Thus, it is important to monitor surgical smoke concentrations in the operating room. In the past decade, many researches regarding surgical smoke were discussed in different professional healthcare fields, but few showed the correlation between surgical smoke and otolaryngology surgery. In this study, the concentrations of particulate matter and formaldehyde were measured during thirty cases of several types of otolaryngology surgery in a regional research hospital in Taiwan. The concentrations of 0.3 µm and 0.5 µm particulate matter raised rapidly in the main knife range at the beginning of the electrocautery knife used, and then decreased by half after 5-10 min of use. The concentrations of formaldehyde were ranged from 1 to 2 ppm during the surgery, which is higher than the permissible exposure limit. While many medical staffs are working in the operating room and are exposed to the smoke hazard, effective strategies for collecting and eliminating the smoke should be taken in all medical facilities.

Comparison of effects of energy based devices on quality of life after sutureless thyroidectomy.

OBJECTIVE: In current literature, no studies evaluated effect of energy-based vessel-sealing-devices on quality of life after sutureless total thyroidectomies. This study aimed to identify any potential differences between two energy-based vessel-sealing-devices (Harmonic Focus, Ligasure LF1212) in patients with benign thyroid disorders who underwent sutureless total thyroidectomy. MATERIALS AND METHODS: Differences in quality of life of patients were evaluated using data obtained by Thy-PRO-39-Tr questionnaire prior to and four-week after surgery. Total and domain-based alterations in quality of life were compared between groups according to energy-based vessel-sealing-devices type (Group L, Group H). Additionally, data including demographics, height, weight, body mass index, neck circumference, sternomental distance were collected. RESULTS: Of 1032 patients, 200 were eligible for study, at the end 193 were analysed. There were no differences between groups in terms of age, sex, body mass index, tobacco use. Analysis did not reveal any differences in overall quality of life between groups (P = .42). However, in "eye symptoms" (P < .001) and "cognitive functions" (P = .002) domains, Harmonic provided statistically improved quality of life. Effect on cognitive function was greater in patients of advanced age. CONCLUSIONS: Especially in elderly patients with worsening eye conditions and cognitive functions, use of Harmonic may enhance patients' outcome by increasing quality of life in addition to optimizing surgical outcome when compared to Ligasure.

Ultrasonic bone removal from the ossicular chain affects cochlear structure and function.

INTRODUCTION: Ultrasonic bone removal devices (UBD) are capable of cutting through bony tissue without injury to adjacent soft tissue. The feasibility and safety of using this technology for removal of bone from an intact ossicular chain (as might be required for otosclerosis or congenital fixation) was investigated in an animal model. METHODS: This was a prospective animal study conducted on seven anesthetised adult chinchillas. An UBD was used to remove bone from the malleus head in situ. Pre and post-operative distortion product otoacoustic emission (DPOAE) levels and auditory brainstem response (ABR) thresholds were recorded. Scanning electron microscopy (SEM) was used to assess cochlear haircell integrity. RESULTS: Precise removal of a small quantity of bone from the malleus head was achieved by a 30s application of UBD without disruption of the ossicular chain or tympanic membrane. DPOAEs became undetectable after the intervention with signal-to-noise ratios (SNR) < 5 dB SPL in all ears. Furthermore, ABR thresholds were elevated > 85 dB SPL in 13 ears. SEM showed significant disruption of structural integrity of the organ of Corti, specifically loss and damage of outer haircells. CONCLUSIONS: Although UBD can be used to reshape an ossicle without middle ear injury, prolonged contact with the ossicular chain can cause structural and functional injury to the cochlea. Extensive cochlea pathology was found, but we did not investigate for recovery from any temporary threshold shift. In the authors' opinion, further study should be undertaken before consideration is given to use of the device for release of ossicular fixation.

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.

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.

MR Imaging-Guided Transurethral Ultrasound Ablation of Localized Prostate Cancer: Preliminary Experience from a Single Center in a Prospective, Multi-Center, Single-Arm Clinical Trial.

This report details a single-center experience of using magnetic resonance imaging-guided transurethral ultrasound ablation (TULSA) for whole-gland prostate treatment. Nine men with organ-confined low-to-intermediate-risk prostate cancer underwent the TULSA procedure. The primary endpoint of reduction of more than 75% was achieved in 8 of 9 patients, and all patients demonstrated a histologic benefit at 12-month biopsy. No major urinary or gastrointestinal side effects were observed, and there were no postprocedural changes in erectile firmness. These findings suggest that TULSA is potentially safe and efficacious for patients with low-to-intermediate-risk disease.

Effects of ultrasound energy on the porcine corneal endothelium - Establishment of a phacoemulsification damage model.

PURPOSE: The purpose of this study was to establish a standardized in vitro phacoemulsification damage model for future investigations of the effects of phacoemulsification, surgical devices, protective ophthalmic viscoelastic devices (OVDs), irrigation solutions and other aspects related to cataract phacoemulsification surgery on the corneal endothelium using porcine eyes. METHODS: Thirty-four porcine eyes were randomly assigned to three groups (phacoemulsification (n = 13), irrigation (n = 9), control (n = 12)). A total of 5 min of ultrasound energy with intermittent irrigation/aspiration was applied in the eyes of the phacoemulsification group. The eyes of the irrigation group received the identical treatment, but without the application of ultrasound energy. The control group was left untreated. All eyes were then prepared to split corneal buttons followed by 15 days of cultivation. Endothelial cell density (ECD) was assessed blinded on day 15. RESULTS: Endothelial cell density declined significantly more until day 15 in the phacoemulsification group (2567 ± 317/267 cells/mm² (median ± 25%/75%-quartiles), -32.5 ± 7.0/6.4%) compared to the irrigation (3450 ± 350/383 cells/mm², -11.8 ± 5.3/2.6%; p < 0.001) and the control group (3650 ± 288/258 cells/mm², -10.2 ± 3.2/4.6%; p < 0.001). CONCLUSION: The phacoemulsification damage model presented in this study is sensitive to phacoemulsification energy and may reliably be used to investigate various factors involved in phacoemulsification with regard to their influence on corneal endothelial cells. This method is able to replace animal experiments or in vitro cell culture experiments that often do not translate well to the in vivo situation in humans.

Comparison of the harmonic scalpel with scissors in women who experience obturator nerve injury during lymph node dissection for gynaecological malignancies.

OBJECTIVES: Lymphadenectomy is crucial for accurate staging in most gynecological malignancies. Serious complications can occur during the surgery. The present study aimed to present the early and late findings associated with obturator nerve injury, which is rarely observed during lymphadenectomy but can result in serious sequela if not noticed. MATERIAL AND METHODS: The files of the patients who underwent lymphadenectomy at our clinic between 2012 and 2018 were examined. Patients with obturator nerve incisions were identified retrospectively. RESULTS: In total, 287 women patients underwent lymphadenectomy at our clinic between 2012 and 2018. Examination of surgical notes revealed that nine patients underwent obturator nerve incisions using a scissor or a harmonic scalpel (energy- activated ultrasonic scissors). With respect to management of obturator nerve damage, no significant difference was found between the use of a harmonic scalpel and scissors (p < 1.000) and the trendelenburg and lithotomy positions (p < 0.167). In addition, no significant difference was found between laparoscopy and laparotomy in terms of surgical type (p < 0.167). At 6 months post-operatively, sensory-motor examinations and EMG findings of the patients were completely normal. CONCLUSIONS: Surgeries performed for gynaecological malignancies have high mortality and morbidity rates. Moreover, in the event of a complication such as nerve damage during laparoscopy, successful management of the complication before the patient undergoes laparotomy allows the patient to continue benefitting from the advantages of the laparoscopy. The results of our study show that these high-risk surgeries should be performed in advanced and well-equipped medical centres by teams experienced in gynaecological oncology.

Comparison of Ultrasonic Device Versus Bipolar Diathermy Tonsillectomy in Children.

BACKGROUND: Intraoperative bleeding and postoperative pain are two commonest concerns for both patient and surgeon in tonsillectomy. This study was aimed to compare intraoperative blood loss and early postoperative pain between ultrasonic device and bipolar diathermy tonsillectomy in children. METHODS: Prospective, interventional, single blinded, comparative study was carried out from September 2016 to September 2017 including children up to age 15 years who underwent tonsillectomy either by bipolar diathermy or ultrasonic device. Intraoperative blood loss was recorded using standard sized gauge technique. Post-tonsillectomy pain on first five postoperative days (early postoperative pain) was assessed using Visual analog scale for children older than 5 years and FLACC score for children up to 5 years respectively.Means were compared. RESULTS: 38 children (76 tonsils) were included in the study out of which 31 were boys (62 tonsils) and 7 were girls (14 tonsils). The mean intraoperative blood loss in ultrasonic dissection group was 13.94 ml and 13.91 ml in bipolar diathermy group. This difference was not statistically significant (p=0.974). Post-operative pain on 1st, 2nd, 3rd and 4th days were significantly less (p<0.05) in ultrasonic device group compared to bipolar diathermy group. Post-operative pain was less also on 5th post-operative day in ultrasonic device but was not statistically significant (p=0.172). CONCLUSIONS: Tonsillectomy in children using ultrasonic device did not differ from bipolar diathermy tonsillectomy in respect to intraoperative blood loss. However, early postoperative pain was significantly lower in ultrasonic device group.

Lateral thermal spread induced by energy devices: a porcine model to evaluate the influence on the recurrent laryngeal nerve.

BACKGROUND: Recurrent laryngeal nerve (RLN) paralysis is a frequently observed complication after esophagectomy, and thermal injury is considered to be one of the causes. The difference in the lateral thermal spread associated with the grasping range of various energy devices remains unknown. METHODS: Ultrasonic devices (Harmonic® HD1000i and Sonicision™) and a vessel-sealing device (Ligasure™) were studied. We evaluated the temperature of these devices, the activation time required, and the thermal spread on porcine muscle when the devices were used with different grasping ranges (thermal spread study). In addition, we evaluated the influence of thermal spread by short grasping use of the energy devices on the viability of RLN in a live porcine model (NIM study). RESULTS: In the thermal spread study, the temperature of the ultrasonic devices lowered as grasping range increased, whereas the highest temperature of Ligasure was observed when used with two-thirds grasping. The activation time of ultrasonic devices became longer as grasping range increased, whereas the grasping range did not influence the activation time of Ligasure. Thermal spreads 1 mm from the energy devices were unaffected by the grasping ranges. Although the temperature of the Ligasure was lower than that of the ultrasonic devices, thermal spread by Ligasure was significantly greater than that induced by the ultrasonic devices. In the NIM study, the activation of the Sonicision with one-third grasping range did not cause EMG changes at distances of up to 1 mm from the RLN, whereas applying Ligasure with a one-third grasping range 1 mm away from the RLN led to a critical result. CONCLUSIONS: The grasping range did not influence the thermal spread induced by the energy devices. Ultrasonic devices may be safer in terms of lateral thermal spread to the RLN than Ligasure.

Ultrasonic bone scalpel: utility in cervical corpectomy. A technical note.

PURPOSE: Anterior cervical corpectomy and fusion (ACCF) is a technically challenging surgery. Use of conventional instruments like high-speed burr and kerrison rongeurs is associated with high complication rates such as increased blood loss and incidental durotomy. Use of ultrasonic bone scalpel (UBS) in cervical corpectomy helps to minimize such adverse events. METHODS: We performed a retrospective study based on the data of 101 consecutive patients who underwent cervical corpectomies with UBS for different cervical spine pathologies from December 2014 to December 2016. Total duration of surgery, time taken for corpectomy, estimated blood loss, and incidental durotomies were noted. RESULTS: Total surgical time was 30-80 min (59.36 ± 13.21 min) for single-level ACCF and 60-120 min (92.74 ± 21.04 min) for double-level ACCF. Time taken for single-level corpectomy was 2 min 11  ± 10 s and 3 min 41  ± 20 s for double-level corpectomy. Estimated blood loss ranged from 20-150 ml (52.07 ± 29.86 ml) in single level and 40-200 ml (73.22 ± 41.64 ml) in double level. Four (3.96%) inadvertent dural tears were noted, two during single-level corpectomy and other two during double-level corpectomy. CONCLUSIONS: Use of UBS is likely to provide a safe, rapid, and effective surgery when compared to conventional rongeurs and high-speed burr. The advantages such as lower blood loss and lower intra-operative incidental dural tears were noted with the use of UBS.

Investigation of scleral thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration using pig eyes.

PURPOSE: The purpose of this study was to investigate the thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration (PPPEA) using pig eyes. METHOD: Using a 20-gauge (G) vitrectomy system (Accurus®, Fragmatome; Alcon Laboratories) in both the 'open-tip' and 'closed-tip' techniques, PPPEA was performed in pig eyes and the subsequent thermal injuries generated around the scleral wound were measured by infrared thermal imaging (thermography). Post surgery, the state of the scleral wound was observed under a microscope, and a tissue slice containing the scleral wound was then prepared and observed under an optical microscope. RESULTS: Thermography measurements revealed a slight temperature rise around the scleral wound in the open-tip case, yet a marked temperature rise in the closed-tip case. The scleral wound incision produced by the open tip was linear, while that produced by the closed tip was expanded. Histological examination revealed mild degeneration of the sclera around the wound in the open-tip case, yet marked tissue degeneration by thermal injuries in the closed-tip case. CONCLUSION: Our findings showed that in PPPEA, the temperature of the tip of a 20G vitrectomy system rapidly increases due to the closed-tip technique, thus producing obvious thermal damage to the scleral wound. In order to prevent thermal injuries to the scleral wound during PPPEA, it is important to shorten the time of ultrasonic oscillation during surgery as much as possible while the tip is occluded with nuclear fragments.

A Three-Arm Randomized Trial of Different Renal Denervation Devices and Techniques in Patients With Resistant Hypertension (RADIOSOUND-HTN).

BACKGROUND: Both radiofrequency and ultrasound endovascular renal sympathetic denervation (RDN) have proven clinical efficacy for the treatment of hypertension. We performed a head-to-head comparison of these technologies. METHODS: Patients with resistant hypertension were randomly assigned in a 1:1:1 manner to receive either treatment with (1) radiofrequency RDN of the main renal arteries; (2) radiofrequency RDN of the main renal arteries, side branches, and accessories; or (3) an endovascular ultrasound-based RDN of the main renal artery. The primary end point was change in systolic daytime ambulatory blood pressure at 3 months. RESULTS: Between June 2015 and June 2018, 120 patients were enrolled (mean age, 64±9 years±SD; mean daytime blood pressure, 153/86±12/13 mm Hg). Of these, 39 were randomly assigned to radiofrequency main renal artery ablation, 39 to combined radiofrequency ablation of the main artery and branches, and 42 to ultrasound-based treatment. Baseline daytime blood pressure, clinical characteristics, and treatment were well balanced between the groups. At 3 months, systolic daytime ambulatory blood pressure decreased by 9.5±12.3 mm Hg ( P<0.001) in the whole cohort. Although blood pressure was significantly more reduced in the ultrasound ablation group than in the radiofrequency ablation group of the main renal artery (-13.2±13.7 versus -6.5±10.3 mm Hg; mean difference, -6.7 mm Hg; global P=0.038 by ANOVA, adjusted P=0.043), no significant difference was found between the radiofrequency ablation groups (-8.3±11.7 mm Hg for additional side branch ablation; mean difference, -1.8 mm Hg; adjusted P>0.99). Similarly, the blood pressure reduction was not found to be significantly different between the ultrasound and the side branch ablation groups. Frequencies of blood pressure response ≥5 mm Hg were not significantly different (global P=0.77). CONCLUSIONS: In patients with resistant hypertension, endovascular ultrasound-based RDN was found to be superior to radiofrequency ablation of the main renal arteries only, whereas a combined approach of radiofrequency ablation of the main arteries, accessories, and side branches was not. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02920034.

Late Shoulder-Arm Morbidity Using Ultrasound Scalpel in Axillary Dissection for Breast Cancer: A Retrospective Analysis.

BACKGROUND: We aimed to assess whether the use of the harmonic scalpel (HS) in axillary dissection would reduce long-term shoulder-arm morbidity compared to traditional instruments (TIs). MATERIALS AND METHODS: A retrospective analysis on 180 patients who underwent standard axillary dissection for breast cancer between 2007 and 2015 was carried out. All patients were evaluated for postoperative pain, impairment of shoulder-arm mobility, seroma formation in axilla, frozen shoulder, and lymphedema. RESULTS: HS procedure on average was 50% shorter compared to the TI technique. HS reduced by 4.5 times the risk of axillary seroma. TIs were associated with 4 times higher risk of developing a painful frozen shoulder. CONCLUSIONS: Use of the HS was associated with reduced costs and a positive long-term effect on shoulder-arm morbidity. Axillary seromas are not the only reason of later postoperative shoulder-arm morbidity: other mechanisms are hypothesized in the onset of this very disabling disorder.

Lateral thermal spread and recurrent laryngeal nerve paralysis after minimally invasive esophagectomy in bipolar vessel sealing and ultrasonic energy devices: a comparative study.

BACKGROUND: This study aimed to compare the extent of lateral thermal spread of surrounding tissues after the use of advanced bipolar and ultrasonic coagulation and shearing devices. Association between recurrent laryngeal nerve paralysis (RLNP) and such devices was assessed in patients who underwent minimally invasive esophagectomy (MIE). METHODS: LigaSure™ (LS) and Sonicision™ (SONIC) were used. In ex vivo experiments using the porcine muscle, blade temperature and tissue temperature were measured using a thermometer after the activation of both devices. For the clinical assessment, 46 consecutive patients who received MIE were retrospectively assessed. RESULTS: The temperature generated at the blade of both devices increased with the activation time. The blade temperature of LS was significantly lower than that of SONIC (P < 0.001). The blade temperature of SONIC exceeded 100 °C after 3-s activation. The temperature of surrounding tissues after a single activation of the devices decreased with the tissue distance from activation blade. The temperatures of tissues at 1 and 2 mm away from the blade side of LS were significantly lower than those of SONIC (P = 0.001 and P < 0.001, respectively). The temperature of tissue 2 mm away from the blade side of LS increased 6.4 °C from the baseline temperature. Furthermore, the incidence of RLNP in the LS group was lower than that in the SONIC group (P = 0.044). CONCLUSION: This study highlights the necessity of spatial and temporal recognition of the thermal spread of coagulation and shearing devices to reduce the thermal injuries following MIE.

Impact of Ultrasonic Scalpels for Liver Parenchymal Transection on Postoperative Bleeding and Bile Leakage.

BACKGROUND/AIM: Novel techniques for liver parenchymal transection have emerged and they are available to the hepatobiliary surgeon. The aim of our study was to compare two types of ultrasonic scalpels (Lotus and Harmonic) and examine how they perform either alone or in combination with the SonaStar ultrasonic surgical aspiration system regarding postoperative bleeding and bile leakage. PATIENTS AND METHODS: Our prospectively maintained database of patients who underwent liver resections in our Department was reviewed. One hundred and two patients with solid liver lesions underwent liver resection by a senior hepatobiliary surgeon in our department during a period of 51 months. They were divided into four groups according to the devices that were used for liver parenchymal transection. RESULTS: Patients were divided into the following groups: group 1: Lotus, 32 patients (31.4%); group 2: Lotus+SonaStar, 27 patients (26.5%); group 3: Harmonic, 27 patients (26.5%); group 4: Harmonic+SonaStar, 16 patients (15.7%). There were 5 cases of postoperative bleeding and 9 cases of postoperative bile leakage. No significant difference was found concerning postoperative bleeding (group 1: 2/32; 6.3%, group 2: 2/27; 7.4%, group 3: 0/27; 0%, group 4: 1/16; 6.3%) (p=0.577). Furthermore, no actual difference was detected in terms of postoperative bile leakage (group 1: 2/32; 6.3%, group 2: 3/27; 11.1%, group 3: 3/27; 11.1%, group 4: 1/16; 6.3%) (p=0.866). CONCLUSION: Both Lotus and Harmonic ultrasonic scalpels provide adequate and similar results concerning postoperative hemorrhage and cholorrhea.

First-in-Man Experience with a Novel Catheter-Based Renal Denervation System of Ultrasonic Ablation in Patients with Resistant Hypertension.

PURPOSE: To report results of renal denervation (RDN) with the first catheter-based, non-balloon occlusion ultrasonic system in patients with resistant hypertension. MATERIALS AND METHODS: In a multicenter, single-arm trial, 39 patients with resistant hypertension (defined as uncontrolled hypertension while taking ≥ 3 antihypertensive medications) were treated. The cohort consisted of 4 groups: severe resistant hypertension (office systolic blood pressure [OSBP] ≥ 160 mm Hg) treated with a unidirectional catheter (group 1; n = 14); severe resistant hypertension treated with a multidirectional catheter (group 2; n = 18); moderate resistant hypertension (OSBP 140-159 mm Hg) treated with a multidirectional catheter (group 3; n = 5); and recurrent severe resistant hypertension, after an initial response to RF RDN (group 4; n = 2). Blood pressure monitoring was performed for 6 months. RESULTS: Severe adverse events were not noted immediately after the procedure or during follow-up. Treatment time was longer with unidirectional than with multidirectional catheters (36.7 min ± 9.6 vs 11.9 min ± 5.8; P < .001). Mean reductions in office blood pressure (systolic/diastolic) at 1, 3, and 6 months were -26.1/-9.6 mm Hg, -28.0/-9.9 mm Hg, and -30.6/-14.1 mm Hg (P < .01 for all). Per-group analysis showed significant OSBP reduction for groups 1 and 2. Patients with isolated systolic hypertension had a significantly smaller reduction in OSBP after 6 months compared with patients with combined systolic/diastolic hypertension (-16.2 mm Hg ± 18.5 vs -9.9 mm Hg ± 33.4; P < .005). CONCLUSIONS: Use of the RDN system was feasible and safe in this phase I study. Significant blood pressure reductions were observed over 6 months, although less in patients with isolated systolic hypertension.

Skull bone marrow injury caused by MR-guided focused ultrasound for cerebral functional procedures.

OBJECTIVE: One patient for whom an MR-guided focused ultrasound (MRgFUS) pallidotomy was attempted was discovered to have multiple new skull lesions with the appearance of infarcts on the MRI scan 3 months after his attempted treatment. The authors conducted a retrospective review of the first 30 patients treated with MRgFUS to determine the incidence of skull lesions in patients undergoing these procedures and to consider possible causes. METHODS: A retrospective review of the MRI scans of the first 30 patients, 1 attempted pallidotomy and 29 ventral intermediate nucleus thalamotomies, was conducted. The correlation of the mean skull density ratio (SDR) and the maximum energy applied in the production or attempted production of a brain lesion was examined. RESULTS: Of 30 patients treated with MRgFUS for movement disorders, 7 were found to have new skull lesions that were not present prior to treatment and not visible on the posttreatment day 1 MRI scan. Discomfort was reported at the time of treatment by some patients with and without skull lesions. All patients with skull lesions were completely asymptomatic. There was no correlation between the mean SDR and the presence or absence of skull lesions, but the maximum energy applied with the Exablate system was significantly greater in patients with skull lesions than in those without. CONCLUSIONS: It is known that local skull density, thickness, and SDR vary from location to location. Sufficient energy transfer resulting in local heating sufficient to produce a bone lesion may occur in regions of low SDR. A correlation of lesion location and local skull properties should be made in future studies.

Ultrasonic versus monopolar energy-based surgical devices in terms of surgical smoke and lateral thermal damage (ULMOST): a randomized controlled trial.

BACKGROUND: The purpose of this study was to compare the degree of surgical smoke or vapor and lateral thermal damage caused by two different energy-based surgical devices (ESDs) used in colpotomy during total laparoscopic hysterectomy. METHODS: Patients undergoing laparoscopic hysterectomy were randomly assigned to an ultrasonic ESD group (n = 20) or monopolar ESD group (n = 20). Colpotomy was performed using the assigned ESD. The degree of surgical smoke or vapor obstructing the laparoscopic view was assessed by two independent reviewers using a 5-point Likert scale, in which a higher score indicates worse visibility. The degree of the lateral thermal damage was measured as the width from the point of instrument application to the margins of the unchanged nearby tissue using a light microscope. RESULTS: The baseline characteristics did not statistically differ between the two groups. The degree of surgical smoke or vapor obstructing vision was 1.2 ± 0.8 points in the ultrasonic group and 3.9 ± 0.7 points in the monopolar groups (p < 0.001). The lateral thermal damage was significantly increased in the monopolar group compared to in the ultrasound group (1500 µm [1200-2500 µm] vs. 950 µm [650-1725 µm], p = 0.037). CONCLUSION: Ultrasonic ESD had better laparoscopic visibility and caused less lateral thermal damage during colpotomy compared to monopolar device.