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We report results from an acute, single case study in the pig liver on the effects of a tissue ablation protocol (we named cryoelectrolysis) in which 10 min of cryosurgery, with a commercial cryosurgical probe, are delivered after 10 min of electrolysis generated by a current of about 60 mA. The histological appearance of tissue treated with cryoelectrolysis is compared with the appearance of tissue treated with 10 min of cryosurgery alone and with 10 min of electrolysis alone. Histology done after 3 h survival shows that the mixed rim of live and dead cells found around the ablated lesion in both cryosurgery and electrolytic ablation is replaced by a sharp margin between life and dead cells in cryoelectrolysis. The appearance of the dead cells in each, cryoelectrolysis, cryosurgery and electrolytic ablation is different. Obviously, this is an acute study and the results are only relevant to the conditions of this study. There is no doubt that additional acute and chronic studies are needed to strengthen and expand the findings of this study.

Irreversible electroporation (IRE) is a nonthermal ablation modality employed to induce in situ tissue-cell death. This study sought to evaluate the efficacy of a novel high-frequency IRE (H-FIRE) system to perform hepatic ablations across, or adjacent to, critical vascular and biliary structures. Using ultrasound guidance H-FIRE electrodes were placed across, or adjacent to, portal pedicels, hepatic veins, or the gall bladder in a porcine model. H-FIRE pulses were delivered (2250 V, 2-5-2 pulse configuration) in the absence of cardiac synchronization or intraoperative paralytics. Six hours after H-FIRE the liver was resected and analyzed. Nine ablations were performed in 3 separate experimental groups (major vessels straddled by electrodes, electrodes placed adjacent to major vessels, electrodes placed adjacent to gall bladder). Average ablation time was 290 ± 63 seconds. No electrocardiogram abnormalities or changes in vital signs were observed during H-FIRE. At necropsy, no vascular damage, coagulated-thermally desiccated blood vessels, or perforated biliary structures were noted. Histologically, H-FIRE demonstrated effective tissue ablation and uniform induction of apoptotic cell death in the parenchyma independent of vascular or biliary structure location. Detailed microscopic analysis revealed minor endothelial damage within areas subjected to H-FIRE, particularly in regions proximal to electrode insertion. These data indicate H-FIRE is a novel means to perform rapid, reproducible IRE in liver tissue while preserving gross vascular/biliary architecture. These characteristics raise the potential for long-term survival studies to test the viability of this technology toward clinical use to target tumors not amenable to thermal ablation or resection.

Lasers precisely cut tissue and are a candidate tool for minimally destructive tissue harvest. A Ho:YAG laser microbiopsy system, using two axicons and an aspheric focusing lens, successfully harvested submillimeter tissue sections from porcine skin.

In the technology driven era, robot assisted surgery is gradually emerging as a revolutionized surgical procedure over traditional laparoscopic method. Despite the concerns about robotic surgery for minimally invasive surgical procedures, robotized surgical arms have been used in many hospitals. Certain surgical procedures require removal of a segment of an organ or body part like excision biopsy, linear thin layer of soft tissue, triangular mass, and tangential excision in burn management, where shaving-off at an angle of the tissue layer to be removed. For such minimally invasive procedures, we have designed a surgical arm governed by a rotary flexible joint. The surgical arm has a medical grade scalpel in its one end and the other end is connected to a D.C. servo motor. The motion of the surgical arm is controlled by the newly designed non-integer order controller. We have experimentally demonstrated the functioning of the surgical arm by ablating the tissue in-vitro. Our surgical robotic arm is cost effective, high precision and free from potential human errors.

Catheter directed ultrasound (US) transducer is capable of delivering high, focused acoustic power to the target tissue inside a body. The direct interaction with the tissue enables to minimize the concern of unintended tissue damages. Despite the potential advantages, the current therapeutic application of the intracavitary US device and literature is due to the inefficient delivery of the acoustic power from the small aperture and difficulty in fabrication. Therefore, we aim to develop a miniaturized intracavitary US transducer for tissue ablation. The proposed device is composed of double-layered PZT-5A, a matching layer, and a backing layer. Relatively high acoustic pressure (4.7 MPa) was generated by the small aperture (2 mm) prototypes. The therapeutic efficacy of the proposed method was validated through ex-vivo tests using porcine kidneys. Upon the sonification, the tissue temperature elevated to over 43 °C within 20 sec and the maximum temperature reached up to 53 °C at the five-minute sonification. The lesion volume after the US treatment was about 6.8 mm3. The developed catheter US transducer can be used to ablate a tumor in deep organs of the body by guiding it through an endoscopic device.

The conditions for deep, controlled, low-temperature (cavitational) laser dissection of biological tissues through the formation of a directional wave of enlightenment are considered.

Radio frequency ablation (RFA) is a proven technique for eliminating cancerous or dysfunctional tissues in the body. However, the delivery of RFA electrodes to deep tissues causes damage to overlying healthy tissues, while a minimally invasive RFA technique would limit damage to targeted tissues alone. In this manuscript, we propose a wireless RFA technique relying on the absorption of radio frequencies (RFs) by gold nanowires in vivo and the deep penetration of RF into biological tissues. Upon optimizing the dimensions of the gold nanowires and the frequency of the applied RF for breast cancer and myocardium tissues, we find that heating rates in excess of 2000 K/s can be achieved with high spatial resolution in vivo, enabling short heating durations for ablation and minimizing heat diffusion to surrounding tissues. The results suggest that gold nanowires can act as “radiothermal” agents to concentrate heating within targeted tissues, negating the need to implant bulky electrodes for tissue ablation.

Ultrasound-induced cavitation has been demonstrated to induce numerous bioeffects, including tissue ablation and drug delivery. Different types of cavitation activity (e.g., inertial or stable) nucleate different bioeffects and are associated with distinct regimes of ultrasonic emissions. Thus decades of research have investigated the emission-bioeffect relationship. Since 2008, beamforming of cavitation emissions has been performed to provide images of cavitation activity. This enables the spatio-temporal localization, characterization, and quantification of cavitation activity, which has been shown to have utility in both image-guidance of therapies and basic science studies. The goal of this tutorial is to familiarize participants with the principles and implementation techniques for array-based passive cavitation monitoring. We will begin with a review the fundamentals of time-domain and frequency-domain beamforming, including an opportunity to form images during the tutorial using data and MATLAB code provided by the speakers. Next, we will discuss steps to correct for propagation path and hardware-specific effects in order to provide improved cavitation dose estimates. Display considerations and B-mode duplex imaging topics will follow. Finally, common hardware configurations, including benefits and limitations, will be covered to provide guidance for individuals considering a setup in their laboratory.

Introduction Irreversible electroporation (IRE) offers an alternative to thermal tissue ablation in situ . High-frequency IRE (H-FIRE), employing ultra-short bipolar electrical pulses, may overcome limitations associated with existing IRE technology to create rapid, reproducible liver ablations in vivo . Methods IRE electrodes (1.5 cm spacing) were inserted into the hepatic parenchyma of swine (n = 3) under surgical anesthesia. In the absence of paralytics or cardiac synchronization five independent H-FIRE ablations were performed per liver using 100, 200, or 300 pulses (2250 V, 2-5-2 μs configuration). Animals were maintained under isoflurane anesthesia for 6 h prior to analysis of ablation size, reproducibility, and apoptotic cell death. Results Mean ablation time was 230 ± 31 s and no EKG abnormalities occurred during H-FIRE. In 1/15 HFIRE's minor muscle twitch (rectus abdominis) was recorded. Necropsy revealed reproducible ablation areas (34 ± 4 mm 2 , 88 ± 11 mm 2 and 110 ± 11 mm 2 ; 100-, 200- and 300-pulses respectively). Tissue damage was predominantly apoptotic at pulse delivery ≤200 pulses, after which increasing evidence of tissue necrosis was observed. Conclusion H-FIRE can be used to induce rapid, predictable ablations in hepatic tissue without the need for intraoperative paralytics or cardiac synchronization. These advantages may overcome limitations that restrict currently available IRE technology for hepatic ablations.

Microwave ablation (MWA) applicators capable of creating directional heating patterns offer the potential of simplifying treatment of targets in proximity to critical structures and avoiding the need for piercing the tumour volume. This work reports on improved directional MWA antennas with the objectives of minimising device diameter for percutaneous use (≤ ∼13 gauge) and yielding larger ablation zones.Two directional MWA antenna designs, with a modified monopole radiating element and spherical and parabolic reflectors are proposed. A 3D-coupled electromagnetic heat transfer with temperature-dependent material properties was implemented to characterise MWA at 40 and 77 W, for 5 and 10 min. Simulations were also used to assess antenna impedance matching within liver, kidney, lung, bone and brain tissue. The two antenna designs were fabricated and experimentally evaluated with ablations in ex vivo tissue at the two power levels and treatment durations (n = 5 repetitions for each group).The computed specific absorption rate (SAR) patterns for both antennas were similar, although simulations indicated slightly greater forward penetration for the parabolic antenna. Based on simulations for antennas inserted within different tissues, the proposed antenna design appears to offer good impedance matching for a variety of tissue types. Experiments in ex vivo tissue showed radial ablation depths of 19 ± 0.9 mm in the forward direction for the applicator with spherical reflector and 18.7 ± 0.7 mm for the applicator with parabolic reflector.These results suggest the applicator may be suitable for creating localised directional ablation zones for treating small and medium-sized targets with a percutaneous approach.

The effect of the pulse repetition rate on ablation performance was evaluated ex vivo at various fiber sweeping speeds for an effective 532-nm laser prostatectomy. Three pulse repetition rates (7.5, 15, and 30 kHz) at 100 W were delivered to bovine liver tissue at three sweeping speeds (2, 4, and 6 mm/s) to achieve bulky tissue removal. Ablation performance was quantitatively compared in terms of the ablation volume and the coagulation thickness. The lowest pulse repetition rate of 7.5 kHz attained the highest ablation volume (101.5 ± 12.0 mm3) and the thinnest coagulation (0.7 ± 0.1 mm) along with superficial carbonization. The highest pulse repetition rate of 30 kHz was associated with the least tissue removal (65.8 ± 5.0 mm3) and the deepest thermal denaturation (1.1 ± 0.2 mm). Quantitative evaluations of laser parameters can be instrumental in facilitating ablation efficiency and maintaining hemostatic coagulation during treatment of large-sized benign prostate hyperplasia.

To evaluate and compare postoperative changes in prostate volume and clinical outcome after bipolar plasma vaporization (BPV) and conventional transurethral resection of the prostate (TURP).Consecutive series of patients undergoing BPV or TURP were included in this prospective, nonrandomized study. Planimetric volumetry after transrectal three-dimensional ultrasound of the prostate was performed preoperatively and postoperatively after 6 weeks, 6 months and 12 months. Additionally, changes in clinical outcome parameters were assessed and compared between the groups. The reduction ratio and analysis of covariance were used to compare volume changes between BPV and TURP. Multiple regression analysis was performed to assess a possible interaction between preoperative prostate volume and effect of therapy.A total of 157 patients were included (BPV: n = 68, TURP: n = 89). Median preoperative prostate volume was 43.1 ml in the BPV group and 45.9 ml in the TURP group (p = 0.43). Postoperatively, the prostate volumes decreased significantly in both groups. After catheter removal, the relative residual prostate volume was significantly higher in the BPV group (66.6 vs. 60.8 %; p = 0.02). Thereafter, significant differences were not detectable anymore (12 months: 46.6 vs. 47.1 %; p = 0.82). Regression analysis revealed that tissue ablation after BPV was superior to TURP in prostates45 ml but inferior in prostates45 ml. All clinical outcome parameters improved significantly and were not significantly different between the groups.Volume reduction and short-term clinical outcome following pure BPV was excellent and comparable to conventional TURP. However, volume reduction seems to be limited in patients with larger prostates.

There is growing interest in performing hyperthermia treatments with clinical magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) therapy systems designed for tissue ablation. During hyperthermia treatment, however, due to the narrow therapeutic window (41-45 °C), careful evaluation of the accuracy of proton resonant frequency (PRF) shift MR thermometry for these types of exposures is required.The purpose of this study was to evaluate the accuracy of MR thermometry using a clinical MR-HIFU system equipped with a hyperthermia treatment algorithm.Mild heating was performed in a tissue-mimicking phantom with implanted temperature sensors using the clinical MR-HIFU system. The influence of image-acquisition settings and post-acquisition correction algorithms on the accuracy of temperature measurements was investigated. The ability to achieve uniform heating for up to 40 min was evaluated in rabbit experiments.Automatic centre-frequency adjustments prior to image-acquisition corrected the image-shifts in the order of 0.1 mm/min. Zero- and first-order phase variations were observed over time, supporting the use of a combined drift correction algorithm. The temperature accuracy achieved using both centre-frequency adjustment and the combined drift correction algorithm was 0.57° ± 0.58 °C in the heated region and 0.54° ± 0.42 °C in the unheated region.Accurate temperature monitoring of hyperthermia exposures using PRF shift MR thermometry is possible through careful implementation of image-acquisition settings and drift correction algorithms. For the evaluated clinical MR-HIFU system, centre-frequency adjustment eliminated image shifts, and a combined drift correction algorithm achieved temperature measurements with an acceptable accuracy for monitoring and controlling hyperthermia exposures.

An increasingly-popular treatment for ablation of cancerous and non-cancerous masses is thermal ablation by radiofrequency joule heating. Real-time monitoring of the thermal tissue ablation process is essential in order to maintain the reliability of the treatment technique. Common methods for monitoring the extent of ablation have proven to be accurate, though they are time-consuming and often require powerful computers to run on, which makes the clinical ablation process more cumbersome and expensive due to the time-dependent nature of the clinical procedure. In this study, a Machine Learning (ML) approach is presented to reduce the time to calculate the progress of ablation while keeping the accuracy of the conventional methods. Different setups were used to perform the ablation and collect impedance data at the same time and different ML algorithms were tested to predict the ablation depth in three dimensions, based on the collected data. In the end, it is shown that an optimal pair of hardware setup and ML algorithm were able to control the ablation by estimating the lesion depth within an average of micrometer-magnitude error range while keeping the estimation time within 5.5 s on conventional x86-64 computing hardware.

Electroporation is a physical phenomenon resulting from transient changes in the permeability and electrical conductivity in the plasma and nuclear membranes of a cell.

El avance de la medicina, las prácticas quirúrgicas enmarcados en principios bioéticos y el descubrimiento de nuevas drogas inmunosupresoras consolidaron el trasplante como método terapéutico a nivel mundial aumentado la esperanza y calidad de vida de miles de habitantes en todo el mundo. Sin embargo, los órganos disponibles no son suficientes para dar satisfacción a la creciente demanda global de trasplantes -más de 87.000 en Europa. En Argentina, el Instituto Central Único Coordinador de Ablación e Implante -que impulsa, coordina y fiscaliza la procuración– informó que, en junio de 2018, los pacientes en lista de espera de órganos y tejidos (LE) y Enfermedad Renal Crónica ascendieron a 10.979.La finalidad de la investigación fue abordar la realidad argentina, su marco legal y vinculación con el “Modelo Español”, el procedimiento de ablación-trasplante; el sistema de asignación de órganos (“SINTRA”), las características de la nueva ley conocida como “Justina”. Y la importancia de repensar protocolos de actuación sanitario y judicial en los casos de pedidos de autorización judicial para la ablación de órganos y tejidos (muertes traumáticas o donaciones entre vivos) como así también la aplicación de nuevas Tecnologías de Información y Comunicación (TICs) en dichos procedimientos para garantizar la salud y seguridad jurídica, tanto de donantes como receptores. The advancement of medicine, surgical practices framed in bioethical principles and the discovery of new immunosuppressive drugs consolidated transplantation as a therapeutic method worldwide, increasing the hope and quality of life of thousands of inhabitants worldwide. However, the availableorgans are not enough to satisfy the growing global demand for transplants - more than 87,000 in Europe. In Argentina, the Central Unique Institute Coordinator of Ablation and Implant - which promotes, coordinates and oversees the procurement - reported that, in June 2018, patients on the waiting list of organs and tissues (LE) and Chronic Kidney Disease amounted to 10979.The purpose of the investigation was to address the Argentine reality, its legal framework and its link with the "Spanish Model", the ablation-transplant procedure; the system of organ allocation ("SINTRA"), the new legislation features known as “Justine Law”. Finally, it is important to reconsider judicial and policeaction protocols in judicial authorization procedures for organ and tissue ablation (violent deaths or inter vivos donation);as well as the impact of Information and Communication Technologies (ICTs) in said procedures to preserve the health and legal certainty of both donors and future recipients.

Irreversible electroporation (IRE), is a new non-thermal tissue ablation technology in which brief high electric field pulses are delivered across the target tissue to induce cell death by irreversible permeabilization of the cell membrane. A deficiency of conventional IRE is that the ablation zone is relatively small, bounded by the irreversible electroporation isoelectric field margin. In the previous studies we have introduced a new treatment protocol that combines few short high voltage (SHV) pulses with long low-voltage (LLV) pulses. In the previous studies, we also have shown that the addition of few SHV pulses increases by almost a factor of two the area ablated by a protocol that employs only the LLV pulses. This study employs potato and gel phantom to generate a plausible explanation for the mechanism. The study provides circumstantial evidence that the mechanism involved is the production of electrolytic compounds by the LLV pulse sequence, which causes tissue ablation beyond the margin of the irreversible electroporation isoelectric field generated by the SHV pulses, presumable to the reversible electroporation isoelectric field margin generated by the SHV pulses.

Ambient Mass Spectrometry (MS) analysis is widely used to characterize biological and non-biological samples. Advancements that allow rapid analysis of samples by ambient methods such as Desorption Electrospray Ionization Mass Spectrometry (DESI-MS) and Rapid Evaporative Ionization Mass Spectrometry (REIMS) are discussed. A short, non-comprehensive overview of ambient MS is provided that only contains example applications due to space limitations. A spatially encoded mass spectrometry analysis concept to plan cancer resection is introduced. The application of minimally destructive tissue ablation probes to survey the surgical field for sites of pathology using on-line analysis methods is discussed. The technological challenges that must be overcome for ambient MS to become a robust method for intrasurgical pathology assessments are reviewed.

Electrosurgery, i.e. the application of radiofrequency current for tissue ablation, is a frequently used treatment for many cardiac arrhythmias. Electrophysiological and anatomic mapping, as well as careful radiofrequency power control typically guide the radiofrequency ablation procedure. Despite its widespread application, accurate monitoring of the lesion formation with sufficient spatio-temporal resolution remains challenging with the existing imaging techniques. We present a novel integrated catheter for simultaneous radiofrequency ablation and optoacoustic monitoring of the lesion formation in real time and 3D. The design combines the delivery of both electric current and optoacoustic excitation beam in a single catheter consisting of copper-coated multimode light-guides and its manufacturing is described in detail. The electrical current causes coagulation and desiccation while the excitation light is locally absorbed, generating OA responses from the entire treated volume. The combined ablation-monitoring capabilities were verified using ex-vivo bovine tissue. The formed ablation lesions showed a homogenous coagulation while the ablation was monitored in realtime with a volumetric frame rate of 10 Hz over 150 seconds.

© 2015 Elsevier Inc. All rights reserved. Electroporation, the permeabilization of the cell membrane by brief, high electric fields, has become an important technology in medicine for diverse application ranging from gene transfection to tissue ablation. There is ample anecdotal evidence that the clinical application of electroporation is often associated with loud sounds and extremely high currents that exceed the devices design limit after which the devices cease to function. The goal of this paper is to elucidate and quantify the biophysical and biochemical basis for this phenomenon. Using an experimental design that includes clinical data, a tissue phantom, sound, optical, ultrasound and MRI measurements, we show that the phenomenon is caused by electrical breakdown across ionized electrolysis produced gases near the electrodes. The breakdown occurs primarily near the cathode. Electrical breakdown during electroporation is a biophysical phenomenon of substantial importance to the outcome of clinical applications. It was ignored, until now.

Electrolytic ablation is a minimally invasive tissue ablation technique that operates by delivering low magnitude direct current to the target region over long periods of time, generating electrolytic products that destroy cells. Our study seeks to examine the hypothesis that permeabilizing the cell membrane with reversible electroporation will reduce the electrolytic dose required for tissue ablation, by exposing the interior of the cell to the electrolytic products. The hypothesis is examined by evaluating the extent of tissue damage when electrolytic and reversible electroporation sequences are delivered separately and in combination, it in vivo, to rat liver tissue. The study shows that combining reversible electroporation with electrolysis produces a substantial increase in the extent of tissue ablation compared to that achieved by electrolysis alone.

The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue.With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 μm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy.The overall mean ID was 2 mm (0.25-4.39) and the mean width was 1 mm (0.3-3.1). The mean coagulation thickness was 0.48 mm (0.25-1.73). The higher the frequency and energy, the deeper and wider was the incision p 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p 0.119.The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

Diagnostic ultrasound has been clinically used for decades. More recently, high intensity focused ultrasound (HIFU) has been developed for therapeutic use as a non-invasive technique for tissue ablation. HIFU is also being investigated for advanced applications at the cellular level. Under guidance by magnetic resonance or ultrasound imaging, HIFU can achieve precise biological effects in tissue with a high safety profile. In this article, we discuss the basic principles, advantages and limitations of HIFU. We will also address the food and drug administration (FDA) approved clinical applications in the United States and highlight active HIFU research with promising clinical outcomes.

Purpose – Electric fields (EFs) are known to influence cell and tissue activity. This influence can be due to thermal or non-thermal effects. While the non-thermal effects are still matter of discussion, thermal effects might be detrimental for cell and tissue viability due to thermal damage, this fact being exploited by applications like hyperthermia and tissue ablation. The paper aims to discuss these issues. Design/methodology/approach – In this work the authors investigate the influence of thermal damage in the consolidation of bone formation during electrostimulation (ES). The authors introduce a mathematical model describing the migration of osteoprogenitor cells, the thermal variation, the thermal damage accumulation and the formation of new bone matrix in an injury (fracture) site. Findings – Numerical results are in agreement with experimental data and show that EFs more intense than 7.5 V/cm are detrimental for the viability of osteoprogenitor cells and the formation of new bone. Originality/value – The model is suitable to conduct dosimetry studies in support of other different ES techniques aimed at improving bone and soft tissues repair.

Aim The aim of this study was to assess changes in corneal biomechanical properties in myopic eyes after laser in-situ keratomileusis (LASIK) with ocular response analyzer. Materials and methods Corneal biomechanics was recorded before and 1 month after LASIK was done in 76 eyes for correction of myopia. Central corneal thickness (CCT) was also measured prior and 1 month postoperatively. Preoperative biomechanical values were compared with postoperative values and both were correlated with age, sex, and CCT and tissue ablation depth. Results In all, 76 eyes of 38 patients were involved in this study. Mean preoperative corneal hysteresis (CH) and corneal resistance factor (CRF) were 9.7 ± 1.7 and 10.1 ± 1.7 mmHg respectively. Mean preoperative Goldmann correlated intraocular pressure (IOPg) and corneal compensated intraocular pressure (IOPcc) were 16.2 ± 3.8 and 17.3 ± 3.9 mmHg, respectively. There was a statistically significant reduction of these parameters postoperatively (CH = 8.0 ± 1.6, CRF = 7.4 ± 1.8, IOPg = 11.7 ± 3.1, and IOPcc = 14.4 ± 2.6) mmHg. A moderate positive significant correlation between CCT and CH, CCT and CRF was found. Conclusion Corneal biomechanics represented in CH and CRF showed statistically significant reduction following LASIK.

A nano-second mode-locked Er: Yb fiber laser has been employed to generate gain-switched pulses of sub-100 ns duration from a thulium fiber laser cavity with a wavelength near water absorption peak. Potential application in tissue ablation surgery is under study.

Modern electrosurgical tools have a specific coagulation mode called “soft coagulation”. However, soft coagulation has not been widely accepted for surgical operations. To optimize the soft coagulation environment, we developed a novel suction device integrated with an electrosurgical probe, called the “Suction ball coagulator” (SBC). In this study, we aimed to optimize the SBC design with a prototyping process involving a bench test and preclinical study; then, we aimed to demonstrate the feasibility, safety, and potential effectiveness of the SBC for laparoscopic surgery in clinical settings. SBC prototyping was performed with a bench test. Device optimization was performed in a preclinical study with a domestic swine bleeding model. Then, SBC was tested in a clinical setting during 17 clinical laparoscopic colorectal surgeries. In the bench tests, two tip hole sizes and patterns showed a good suction capacity. The preclinical study indicated the best tip shape for accuracy. In clinical use, no device-related adverse event was observed. Moreover, the SBC was feasible for prompt hemostasis and blunt dissections. In addition, SBC could evacuate vapors generated by tissue ablation using electroprobe during laparoscopic surgery. We successfully developed a novel, integrated suction/coagulation probe for hemostasis and commercialized it.

Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is a minimally invasive procedure used to treat various intracranial pathologies. This study investigated the effects of variable power on maximal estimated thermal damage during ablation and duration required to reach maximal ablation.All ablations were performed using the Visualase Thermal Therapy System (Medtronic Inc., Minneapolis, Minnesota), which uses a 980 nm diffusing tip diode laser. Cases were stratified into low, medium and high power. Maximal thermal damage estimate (TDEWe used real-time ablation data from 93 patients across various intracranial pathologies. tIncreased power results in a larger TDE

Histotripsy uses high-pressure, microsecond-length pulses to generate cavitation microbubbles to fractionate targeted tissue. After the collapse of a cavitation cloud, remnant microbubbles can persist for a second or longer before passively dissolving. These bubbles can act as seed nuclei for subsequent cavitation events reducing treatment efficiency because the nuclei are not well distributed through the entire volume. It has been shown that this memory effect can be reduced using a second transducer to generate a long low amplitude burst to stimulate coalescence of remnant bubbles. This study presents an integrated transducer system to deliver both the high amplitude (p-≥ 30 MPa) histotripsy pulses and lower-amplitude (∼ 1 MPa) coalescence sequences to achieve rapid, homogenous ablation.

Purpose To determine the theoretical volumes of flap and tissue ablation altered during laser in situ keratomileusis (LASIK) correction of myopic refractive errors. Setting Rothschild Foundation, Paris, France. Design Experimental study. Methods The theoretical volumes of the flap and ablated corneal lenticules for spherical myopic corrections were calculated by mathematical approximations based on a simplified geometric model. These results were then compared for various zone diameters, dioptric corrections, and the percentage of the volumes altered (PVA) with the percentage of tissue altered (PTA). Results The volume of the flap varied linearly with flap thickness and with the square of the flap diameter. The volume of ablated corneal tissue was estimated to be proportional to the magnitude of myopia treatment and to the 4th power of the treatment diameter. For the same depth of ablation, the volume of tissue ablated can vary significantly, depending on the magnitude of the correction and the optical zone diameter. As a result, the PTA calculation is not predictive of the actual PVA. Conclusions The flap diameters and the laser correction were the most important determinants of the PVA altered during LASIK surgery. New models estimating the volume of the flap and corneal tissue might be necessary to determine their influence on corneal biomechanical stability and each procedure's outcome.