Abstract: Catheter systems of the invention involve guided and informed dissolution of occlusions in blood vessels. According to certain aspects, a catheter system of the invention includes an elongate body defining a first lumen and comprising a distal portion, an inner member configured for insertion into the first lumen, the inner member comprising an energy source configured to deliver therapeutic energy to a treatment site, and an imaging assembly located at the distal portion of the elongate body. In some embodiments, the catheter system includes a functional flow sensor in addition to or as an alternative to the imaging assembly.

Abstract: Electrosurgical lysing methods. In some implementations, the method may comprise delivering a lysing tip through an entrance incision into a patient's body, wherein the lysing tip comprises at least one bead comprising an at least substantially electrically non-conductive surface; and at least one lysing segment extending within a recess defined, at least in part, by the at least one bead. The at least one bead may protrude both distally and proximally relative to the at least one lysing segment. The method may further comprise forming opposing tissue planes using the lysing tip to create an implant pocket; and inserting an implant through the entrance incision and into the implant pocket.

Abstract: A surgical grasper includes jaws that are transitionable between spaced apart and approximated configurations. In particular, the surgical grasper defines an unobstructed lumen for passage of a surgical instrument therethrough.

Abstract: A method, consisting of modeling physical parameters representative of a probe in proximity to body tissue during an ablation procedure performed by the probe. The method also includes measuring a subgroup of the physical parameters during a non-ablation stage of the ablation procedure so as to generate measured non-ablative values of the subgroup, and measuring the subgroup of the physical parameters during an ablation stage of the ablation procedure so as to generate measured ablative values of the subgroup. In response to the modeling, the method includes generating calculated non-ablative values of the subgroup for the non-ablation stage, and generating calculated ablative values of the subgroup for the ablation stage. The method compares the measured non-ablative values with the calculated non-ablative values, and compares the measured ablative values with the calculated ablative values, so as generate optimal values of the physical parameters.

Abstract: A method for determining a predicted lesion size formed in a tissue by receiving or calculating a measure of contact force between the electrode and the tissue, determining a tissue characterization, and calculating the predicted lesion size using both the measure of contact force and the tissue characterization. A system comprising an electronic control unit configured to receive or determine a measure of contact force between the electrode and the tissue, characterize the tissue based on both the measure of impedance and the measure of contact force, and cause the tissue characterization to be either (a) presented to a user, or (b) applied to calculate a metric and cause the metric to be presented to the user.

Abstract: A jaw member, end effector assembly including the jaw member and an ultrasonic blade, and an ultrasonic surgical instrument including the end effector assembly are provided. The jaw member includes a structural body and a jaw liner. The structural body includes a pair of proximal flanges and an elongated distal portion extending distally from the proximal flanges. The elongated distal portion includes spaced-apart side rails defining an elongated opening therebetween and interconnected at distal ends thereof via a distal cap. The jaw liner is engaged within the elongated opening and includes a base and first and second arms extending from the base. Each arm defines an inwardly-angled tissue contacting surface. The jaw liner defines a jaw liner compliance feature extending longitudinally therealong between the inwardly-angled tissue-contacting surfaces of the first and second arms to facilitate outward deflection of the first and second arms relative to one another.

Abstract: A method for performing a medical procedure in an intestine of a patient is provided. The method comprises providing a system comprising: a catheter for insertion into the intestine, the catheter comprising: an elongate shaft comprising a distal portion; and a functional assembly positioned on the shaft distal portion and comprising at least one treatment element. The catheter is introduced into the patient, and target tissue is treated with the at least one treatment element. The target tissue comprises mucosal tissue of the small intestine, and the medical procedure can be configured to treat polycystic ovarian syndrome (PCOS).

Abstract: A technique allows for an electrical connection between a thermal abrasion heating catheter and the energy delivery console that utilizes serial communication. Accordingly, the serial communication allows data such as measured temperature, start/stop status, intended treatment area, device identification, device calibration parameters and/or use history to be conveyed along the same wires that deliver power to a heating element. For example, data can be conveyed along a two wire connection and provided at a frequency that is filtered out so that it is not delivered to a heating feature. In this example, one wire provides power to the heating element, one wire provided communication from the energy delivery console, and a third wire provides a common ground which the heating catheter uses to communicate with the energy delivery console.

Abstract: The present invention provides devices and methods that can prevent or ameliorate bronchoconstriction by stimulating neural activity, in contrast to those techniques based on denervation, ablation or blocking of neural activity. Methods and devices according to the invention may act responsively or on demand, can preserve neuronal structure and function and will be associated with minimal collateral side-effects. In particular, the invention provides devices and methods in which a signal is delivered to the vagus nerve, for example the cervical vagus nerve or the pulmonary branch of the vagus nerve, in order to stimulate neural activity in the vagal nerve.

Abstract: A probe device is disclosed that includes one or more insulating layers and a glassy carbon layer. The glassy carbon layer includes one or more channels. Each channel includes a microstructure, which may include an electrode region, interconnect region, and bump pad region. The electrode region may be placed in contact with a human or animal patient or test subject and used to collect or deliver signals in applications such as electrocorticography (ECoG), electromyography (EMG), and neural stimulation. A method of making a probe includes depositing a glassy carbon precursor on a substrate, patterning the precursor using photolithography, pyrolyzing the precursor to allow the formation of glassy carbon, and depositing one or more insulating layers.

Abstract: A device and method for creating an arteriovenous (AV) fistula includes a proximal base having a distal diagonal end surface and a distal tip connected to the proximal base and movable relative to the proximal base. The distal tip has a proximal diagonal end surface. A heating assembly, including an energized heating element, is disposed one of the distal diagonal end surface and the proximal diagonal end surface. A passive heating assembly is disposed on the mating diagonal end surface. The distal diagonal end surface and the proximal diagonal end surface are adapted to contact opposing sides of a tissue portion to create a fistula. The angle of the proximal diagonal end surface matches the angle of the distal diagonal end surface, so that the two surfaces match one another during deployment.

Abstract: Tumor treating fields (TTFields) can be delivered to a subject's body at higher field strengths by switching off one or more electrode elements in a transducer array that are overheating. This may be accomplished by using thermistors that sense the temperature of each electrode element. Portions of the wiring of each transducer array is shared between the electrode elements and the thermistors by using a plurality of conductors, each of which electrically connects (a) a pin of a connector, (b) a respective electrode element, and (c) a respective thermistor. In some embodiments, all of the thermistors are wired in series. In other embodiments, all the thermistors share a common connection.

Abstract: A method and apparatus are disclosed for using a generator having insufficient power to supply power to a number of electrosurgical probes during ramping up of the probes to reach set point temperatures. The method includes reducing energy delivery to at least one probe by temporarily disabling energy delivery thereto. Some embodiments comprise a method of delivering energy to at least two electrosurgical probes connected to at least two of the channels of a generator wherein the generator has a maximum output, the method comprising: (a) activating channels which are to be activated; (b) checking for disabling conditions; and (c) if there are disabling conditions, disabling the channel which takes the least power amongst all active channels.

Abstract: A spring assembly usable with an intravascular catheter can include a tubular body, two mounting surfaces, and a compressible framework. The tubular body extends along a longitudinal axis and is sized to traverse vasculature. Each mounting surface can be configured to engage a substantially planar electrical circuit and is positioned in the tubular body each in a respective plane perpendicular to the longitudinal axis. The mounting surfaces face toward each other in opposite directions. The compressible framework extends between the first and second mounting surfaces. The spring assembly can further include a pair of electrical circuits mounted to the pair mounting surfaces. Each electrical circuit can include an inductive coil such that the pair of electrical circuits is a distance transducer. A change in distance between the pair of electrical circuits can be detected when the compressible framework is compressed and/or bent.

Abstract: A surgical instrument includes a housing, a shaft extending distally from the housing, an end effector disposed at a distal end of the shaft, an actuator operably coupled to the housing, an actuation assembly, and a sensor module. The actuation assembly extends through the housing and the shaft and includes a distal end operably coupled to the end effector or a component associated therewith, a proximal end operably coupled to the actuator, and a spring. Actuation of the actuator manipulates the end effector or deploys the component relative thereto. The sensor module is disposed within the housing and configured to sense a property of the spring indicative of an amount the spring has been compressed. The sensor module is further configured, based upon the sensed property, to determine a condition of the end effector or the relative position of the component.

Abstract: A modular surgical apparatus is disclosed. Also disclosed is a modular incision apparatus. The modular incision apparatus may be used in a minimally invasive surgery. The modular incision apparatus includes a base having a pair of pivots, a pair of alignment tabs, a proximal opening, and at least one slide guide. The modular incision apparatus includes visual and cleaning access to the blade. The modular incision apparatus is suitable for safely, efficiently, and accurately making small incisions during surgical procedures. The modular incision apparatus provides a means of making small incisions of controlled depth, while reducing the chances of inadvertent exposure of surgical staff to sharp instrument.

Abstract: The invention relates to an auxiliary instrument for insertion into vessels or lumens with small inner diameters. The auxiliary instrument has a proximal end and a distal end and has at least one localization element whose position and orientation can be determined with an electromagnetic position detection system. The localization element is located directly adjacent to or at least close to the distal end of the auxiliary instrument and is configured to capture an alternating electromagnetic field. A distal end region of the auxiliary instrument extends from the distal end of the auxiliary instrument to a proximal end of the localization element such that the localization element is located within the distal end region. In that part of the distal end region in which the localization element is located, the auxiliary instrument has a low bending stiffness of less than 10 Nmm2, at least in sections.

Abstract: A dual-output generator is configured to output two or more waveforms at different frequencies. In particular, the dual-output generator is configured to provide low-frequency output, which may be suitable for ultrasonic surgical instruments, and a high-frequency output, which may be suitable for electrosurgical instruments, while reducing the amplitude of all remaining frequencies other than the two selected low and high frequencies to about zero.

Abstract: An apparatus and methods for a spinal retractor utilizing spirally retracting blades to provide a surgical portal. The retractor system comprises a blade assembly and mechanism to open and close the blades. The blade assembly comprises a set of blades arranged in a mostly circular formation coupled to an actuator. The retractor system utilizes a mechanism such as a slot-and-follower to actuate the blades in a spiral motion. Each blade in the blade assembly maintains tangential contact to each adjacent blade during expansion and contraction of the device. The circumferential retractor blade arrangement completely separates the soft tissue being retracted from the surgical portal being created allowing for the surgical site to be free from any encroaching internal tissue.

Abstract: An electrode assembly for use with an electrophysiological catheter has a plurality of independently controlled ablation electrodes distributed radially around the electrode assembly. Two ablation electrodes may be positioned in opposition to each other. The electrode assembly may also have microelectrodes for sensing tissue and/or temperature. Methods for using a catheter equipped with such an electrode assembly may include preferentially emitting energy in a radial direction.

Abstract: The present disclosure provides a system with an innovative electrode designed as an RF/microwave antenna as well as methods to monitor/assess biological tissue and perform surgical procedures.

Abstract: A vapor delivery needle and method is provided that is adapted for treating prostate cancer. The energy delivery probe can apply condensable vapor energy to tissue, such as a peripheral zone tissue in a human prostate. In one method, a needle is introduced into peripheral zone tissue of a human prostate, and vapor media is delivered through the needle to ablate peripheral zone tissue without ablating non-peripheral zone tissue. Systems for treating prostate cancer with vapor therapy are also provided.

Abstract: An apparatus including a body, a shaft assembly extending distally from the body, and an end effector configured to grasp and transmit RF energy to the tissue. The end effector includes a first jaw having a first tissue grasping feature and a second jaw. The second jaw is pivotably coupled to the first jaw between an open position, a partially closed position, and a closed position. The second jaw includes a proximal taper having a proximal electrode surface, a distal taper including a distal electrode surface, and a juncture between the proximal and distal electrode surface. The juncture is spaced further from the first tissue grasping feature compared to the proximal and distal end while the second jaw is in the partially closed position. The proximal and distal electrode surface deform to define a gap with the first tissue grasping feature while in the closed position.

Abstract: A flexible circuit including a first segment including a base section of the flexible circuit; a second segment including a lateral wall section; a transition section between the base and lateral wall sections, the transition section being at least partially positioned adjacent a shared region of the base and lateral wall sections; and one or more electrode regions including a respective electrode, the one or more electrode regions being positioned at least partially in the transition section and the second segment.

Abstract: A medical device is disclosed, including a handle assembly; an elongate body coupled to the handle assembly, the elongate body defining a guide wire lumen therethrough; and a substantially semi-circular electrode array coupled to the elongate body. The device may include a substantially rigid shaft extending distally from the elongate body and defining a lumen therethrough, the shaft including a substantially rigid segment, and a flexible coil coaxial with and extending distally from the shaft.

Abstract: A surgical instrument and method of operating same includes an end effector and a shaft assembly. The shaft assembly has proximal and distal shaft portions respectively extending along proximal and distal axes, a first elongate member, and an articulation section. The articulation section extends between the proximal and distal shaft portions and is configured to articulate about a first articulation axis and about a second articulation axis to thereby respectively deflect the end effector along a first plane and a second plane. The articulation section has a first lumen radially offset from the proximal and distal axes that longitudinally intersects the first and second articulation axes. The first lumen movably supports the first elongate member such that the radial spacing of the first elongate member is maintained relative to the proximal and distal axes at each of the first and second articulation axes during deflection of the end effector.

Abstract: This document provides devices and methods for the treatment of heart conditions, hypertension, and other medical disorders. For example, this document provides devices and methods for treating atrial fibrillation by performing thoracic vein ablation procedures, including pulmonary vein myocardium ablation. In some embodiments, the ablation is performed in coordination with the delivery a pharmacological agent that can abate the formation of tissue stenosis or neointimal hyperplasia caused by the ablation.

Abstract: A method includes, using anatomical data, calculating multiple cross-sectional shapes of a lumen of an organ in a body of a patient at multiple respective positions on a medial axis of the lumen. One or more of the positions on the medial axis are identified, at which a given expandable frame of a catheter would fit the cross-sectional shapes. The one or more identified positions are presented to a user.

Abstract: Described here are devices, systems, and methods for closing the left atrial appendage. The methods described here utilize a closure device for closing the left atrial appendage and guides or expandable elements with ablation or abrading elements to ablate or abrade the left atrial appendage. In general, these methods include positioning a balloon at least partially within the atrial appendage, positioning a closure assembly of a closure device around an exterior of the atrial appendage, inflating the balloon, partially closing the closure assembly, ablating the interior tissue of the atrial appendage with the inflated balloon, removing the balloon from the atrial appendage, and closing the atrial appendage with the closure assembly.

Abstract: A catheter including an elongated tube having a channel; an inflatable chamber coupled to the elongated tube and in fluid communication with the channel; and a high-density liquid delivery system in fluid communication with the channel, the high-density liquid delivery system delivering a high-density liquid to the inflatable chamber via the channel to cause the inflatable chamber to expand.

Abstract: The present invention relates to comprehensive systems, devices and methods for delivering energy to tissue for a wide variety of applications, including medical procedures (e.g., tissue ablation, resection, cautery, vascular thrombosis, treatment of cardiac arrhythmias and dysrhythmias, electrosurgery, tissue harvest, etc.). In certain embodiments, systems, devices, and methods are provided for treating a tissue region (e.g., a tumor) through application of energy using energy delivery devices having a conductive permanent tip encapsulated in a biocompatible material.

Abstract: Methods, apparatus, and systems for delivering electromagnetic energy to a patient's tissue with a reduction in the pain experienced by the patient. Electromagnetic energy is delivered from a treatment electrode through the skin surface to the tissue at a plurality of power levels over a treatment time. During the energy delivery, a portion of the treatment electrode is in a contacting relationship with the skin surface. A tip frame may be disposed between the treatment electrode and the skin surface when the electromagnetic energy is delivered.

Abstract: An electrosurgical access catheter for assisting a physician perform an ancillary surgical procedure on a region of interest (ROI) in a patient has a tubular shaped elongate shaft and a ring-shaped active electrode located at the distal end. A passageway extends from the proximal section to the distal end of the shaft, and through the ring-shaped active electrode. The proximal section of the elongate shaft is detachably coupled to an electrosurgical controller such that the ring-shaped active electrode is operable with the electrosurgical controller and a dispersive electrode to electrosurgically make a circular-shaped incision through a tissue wall, carving a cylindrical-shaped tissue plug as the ring-shaped active electrode is advanced through the wall. The access sheath is advanced through the surgically created opening and without further dilation of the opening. The invention has particular applicability to the lung, and minimally invasive bronchoscopic procedures. Related methods are also described.

Abstract: Systems and methods for treating a patient's mucus hypersecretion condition are disclosed herein. Certain implementations may involve a method for reducing mucus secretion in an upper airway of a patient to treat at least one of post nasal drip or chronic cough. The method may include advancing a treatment delivery portion of an energy-based treatment device into a nostril of the patient. The treatment delivery portion may contact mucosal tissue of the upper airway without piercing the mucosal tissue. The treatment delivery portion may deliver treatment to at least one tissue selected from the group of the mucosal tissue and another tissue underlying the mucosal tissue to modify a property of the at least one tissue and thus treat at least one of post nasal drip or chronic cough in the patient.

Abstract: Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the removal device. The removal device can have a core assembly that includes a hypotube coupled to a first electrical terminal and a pushwire coupled to a second electrical terminal, the pushwire extending through the hypotube lumen. An insulating layer separates the hypotube and the pushwire, and an interventional element is coupled to a distal end of the pushwire. The interventional element can be disposed adjacent to a thrombus. An electrical signal is delivered to the interventional element to promote adhesion of the thrombus to the interventional element. The electrical signal can optionally be a periodic waveform, and the total energy delivered can be between 0.75-24,000 mJ and the peak current delivered via the electrical signal can be between 0.5-5 mA.

Abstract: The present invention relates to a treatment apparatus including a housing, an insertion unit provided on one side of the housing and formed to be inserted into a tissue through a tissue surface, and a cooling unit cooling the one side of the insertion unit within the housing to prevent thermal damage to the tissue touched when the insertion unit heated during a treatment time is drawn out from or inserted into the tissue, and a method of controlling the same and a treatment method. According to the present invention have effects in that they can prevent a problem in that unnecessary damage to a tissue occurs while maintaining a treatment effect of the skin because the heated end of the insertion unit is cooled and moved.

Abstract: Improved methods and devices for performing an endoscopic surgery are provided. Systems are taught for operatively treating gastrointestinal disorders endoscopically in a stable, yet dynamic operative environment, and in a minimally invasive manner. Such systems include, for example, an endoscopic surgical suite. The surgical suite can have a reversibly expandable retractor that expands to provide a stable, operative environment within a subject. The expansion can be selectively asymmetric to maximize space for a tool and an endoscope to visualize a target tissue and treat the target tissue from outside the patient in a minimally invasive manner.

Abstract: Methods, systems and devices for evaluating the integrity of a uterine cavity. A method comprises introducing transcervically a probe into a patient's uterine cavity, providing a flow of a fluid (e.g., CO2) through the probe into the uterine cavity and monitoring the rate of the flow to characterize the uterine cavity as perforated or non-perforated based on a change in the flow rate.

Abstract: Needles are deployed in tissue under direct ultrasonic or other imaging. To aid in deploying the needle, a visual needle guide is projected on to the image prior to needle deployment. Once the needle guide is properly aligned, the needle can be deployed. After needle deployment, a safety boundary and treatment region are projected on to the screen. After confirming that the safety boundary and treatment regions are sufficient, the patient can be treated using the needle.

Abstract: Ablation systems of the present disclosure facilitate the safe formation of wide and deep lesions. For example, ablation systems of the present disclosure can allow for the flow of irrigation fluid and blood through an expandable ablation electrode, resulting in efficient and effective cooling of the ablation electrode as the ablation electrode delivers energy at a treatment site of the patient. Additionally, or alternatively, ablation systems of the present disclosure can include a deformable ablation electrode and a plurality of sensors that, in cooperation, sense the deformation of the ablation electrode, to provide a robust indication of the extent and direction of contact between the ablation electrode and tissue at a treatment site.

Abstract: Electrosurgical systems and components thereof configured to deliver RF energy to a target site of a human or other animal patient with selectable RF energy delivery profiles, temperature sensors and controls, and/or electrodes configured to more uniformly or effectively delivery energy to target tissue.

Abstract: An endoscopic system includes an elongate shaft, a pull wire that runs a length of the elongate shaft, a handle coupled to a proximal portion of the elongate shaft, the handle housing a proximal portion of the pull wire, the handle being couplable to a robotic driver configured to tension the pull wire to cause articulation of the elongate shaft, and one or more conductors that run the length of the elongate shaft, the one or more conductors being electrically coupled to the pull wire at a distal portion of the elongate shaft and configured to form part of a closed electrical circuit with the pull wire.

Abstract: A catheter has a two-piece tip electrode with a shell and a support structure that are secured to each other by multiple redundant mechanisms in order to reduce the risk of tip detachment during a procedure. The tip electrode includes at least two different welds attaching the shell to the support structure to provide a dual failure mode. One weld includes a seam weld and another weld includes a penetration weld.

Abstract: Apparatus, consisting of a probe configured to be inserted into contact with a myocardium, and an electrode attached to the probe. A temperature sensor, incorporated in the probe, is configured to output a temperature signal. A pump irrigates the myocardium, via the probe, with an irrigation fluid at a controllable rate, and a radiofrequency (RF) signal generator applies RF power via the electrode to the myocardium, so as to ablate the myocardium. The apparatus also has processing circuitry that measures a temperature of the probe, based on the temperature signal, while the RF power is applied and, when the measured temperature exceeds a preset target temperature, iteratively reduces the RF power applied by the signal generator and concurrently iteratively varies a rate of irrigation of the irrigation fluid provided by the pump, until the measured temperature is reduced to the preset target temperature.

Abstract: Devices and methods are described for electrolytically, ultrasonically, or both electrolytically and ultrasonically disrupting debris on an eyelid margin. A device includes an eyelid contacting portion having at least a first electrode, a second electrode, and a power supply electrically coupled to at least one of the first and second electrodes. The eyelid contacting portion may optionally have a shelf separating an upper portion from a lower portion with electrodes on the upper and lower portions. The eyelid contacting portion may optionally include at least one channel with electrodes. The device may optionally include an ultrasonic driver. Another device includes an ultrasonic driver but no electrodes. A method contacts debris on an eyelid margin with a first electrode and contacting a surface of an eyelid with a second electrode and supplying electrical energy to one of the first or second electrodes to disrupt the debris.

Abstract: A biological tissue monitoring system has control circuitry programmed or configured to monitor an impedance of biological tissue. The control circuitry is programmed or configured to receive or determine an impedance measurement of the biological tissue in response to power delivered to the biological tissue at a plurality of frequencies and a plurality of time points, and adjust or cause to be adjusted the power delivered to the biological tissue at a subsequent time point based on the impedance measurement at the plurality of frequencies and the plurality of time points.

Abstract: A histotripsy therapy system configured for the treatment of tissue is provided, which may include any number of features. Provided herein are systems and methods that provide efficacious non-invasive and minimally invasive therapeutic, diagnostic and research procedures. In particular, provided herein are optimized systems and methods that provide targeted, efficacious histotripsy in a variety of different regions and under a variety of different conditions without causing undesired tissue damage to intervening/non-target tissues or structures.

Abstract: A method and apparatus for ablating tissue are disclosed that comprise positioning two or more bi-directional ablation energy sources in spaced-apart relation in sufficient proximity to the tissue to be ablated so that, upon activation each energy source creates an energy field in the tissue to be ablated. The energy sources are spaced such that the energy fields created by at least one of the activated sources partially overlaps with the energy field created by one or more of the other energy sources. The energy sources are alternately activated and deactivated, so that a substantially constant energy field results where the energy fields created by at least two of the energy sources overlap. While the energy sources are preferably RF energy sources, other energy sources, such as microwave, may be used.

Abstract: A forceps having a first jaw and a second jaw, where at least one of the first and second jaws is capable of moving between an open position and a closed positions. The forceps including an inner shaft located within an outer shaft and extending along the longitudinal axis, and a drive bar coupled to and extending distally from the inner shaft. The drive bar including a pair of drive bar struts extending from a distal portion of the inner shaft and positioned laterally inward of at least one of first and second set of flanges of the first and second jaws. A drive pin is securable to the pair of drive bar struts and the drive bar is translatable within the outer shaft to translate the drive pin to move the first jaw and/or the second jaw between open and closed positions.

Abstract: An electrosurgical vessel sealing device that can seal biological vessels using a confined microwave field that yields a well-defined seal location with low thermal margin. The device comprises a pair of jaws that are movable relative to each other to grip biological tissue. A blade for cutting the gripped tissue is slidable between the jaws. A coplanar microstrip antenna is mounted on the inner surface of one or both of the pair of jaws to emit microwave energy into the gap therebetween. The device may comprise a separate dissector element to enable fine tissue cutting and dissection to be performed.