Surgical retractors

The present disclosure relates to methods and devices for surgically manipulating tissue. In general, the methods and devices can include an elongate retractor shaft having a distal retractor tip that is configured to manipulate tissue, for example the tip can be configured to separate muscle and nerve fibers surrounding a vertebra. The elongate retractor shaft can include an illumination source such that at least a portion of the surgical field is illuminated by the device when the device is used in the body. A sensor can also or alternatively be included on the elongate retractor shaft, for example on the blunt retraction tip, such that the sensor can monitor physiological parameters of the tissue in or adjacent to the surgical field.

FIELD

The present disclosure relates generally to surgical retractor devices and methods for manipulating tissue.

BACKGROUND

Surgical procedures for accessing tissue located deep within the body can pose a risk of trauma to the intervening tissue, particularly when the tissue includes neural tissue. During a surgical procedure where access to the spine is required, the final layers of tissue, those most proximate to the spine, are densely populated with large nerve fibers. Since the tissue is nerve-dense, the surgeon must take the greatest care when manipulating the tissue as the deep nerve fibers are remote from the surgeon, follow only general anatomic patterns, and are beneath, within, or above sensitive layers of tissue.

Various configurations of access devices have been developed to gain and maintain access to surgical fields, such as the spinal column, through deep access portals in tissue. For example, Penfield devices have been used in surgical procedures to manipulate muscular and neural tissue. However, the use of a Penfield device requires extending the tip of the Penfield device deep into the access portal to the surgical field. As the Penfield device is disposed within the deep access cavity, the surgeon typically losses visual contact of tissue that is adjacent to the distal tip of the Penfield device. As the surgeon loses sight of the working area, often due to a lack of light in the deep access portal, the likelihood of inadvertent contact and damage of sensitive neural tissue increases.

Accordingly, there remains a need for improved methods and devices for safely performing the surgical retraction of tissue.

SUMMARY

Devices and method are provided for surgically manipulating tissue, such as muscle fibers, including embedded neural tissue within a deep access portal in a body. Specifically, the methods and devices described herein can provide an effective means to manipulate tissue with an increased field of vision for a surgeon. The methods and devices can also provide for monitoring of physical parameters.

In one embodiment, a surgical device for surgically manipulating tissue is provided and can include an elongate retraction shaft having a proximal end with a handle portion, and a distal end having a blunt retraction tip configured to retract tissue within a body without appreciably severing the tissue. The surgical device can also include an illumination source disposed on the elongate retraction shaft and configured to illuminate at least a portion of tissue being manipulated by the retraction tip. Furthermore, the device can have a sensor disposed on the retraction tip that can be configured to sense at least one physiological parameter of tissue being manipulated by the retraction tip. A connector can be coupled to the handle and electrically coupled to at least one of the illumination source and the sensor.

In one embodiment, the connector can be electrically coupled to the sensor and it can be configured to transfer a signal between the sensor and an external signal processor. The device can include an internal power source disposed within the handle portion that can be configured to provide power to at least one of the illumination source and the sensor.

The blunt retraction tip can have a variety of configurations. In one embodiment, the tip can have a concave surface configured to conform to a bone surface. The elongate retraction shaft can be linear or in other embodiments it can be non-linear with at least one bend formed therein such that the blunt retraction tip extends along a central longitudinal axis that is transverse to a central longitudinal axis of the handle portion. In certain embodiments the blunt retraction tip is in the shape of a dissector, such as a Penfield dissector. The elongate retraction shaft can have a lumen extending through at least a portion thereof. In certain embodiments, the connector can extend through the lumen, the illumination source can be at least partially disposed within the lumen, and/or the sensor can be at least partially disposed within the lumen. In some embodiments, the sensor can be laminated to an external surface of the elongate retraction shaft or molded/inserted within the retraction shaft and exposed at a distal portion thereof. Embodiments of an elongate retraction shaft having at least a portion that is malleable are also provided.

The illumination source can include a light emitting diode. While the location can vary, in one embodiment, the illumination source can be disposed proximally adjacent to the retraction tip. The sensor can also have various configurations and can be configured to sense at least one physiological parameter such as temperature, pressure, blood oxygen level, neuro conductivity, or combinations thereof. In another embodiment, the retraction tip can be removably coupled to the elongate retraction shaft.

In one embodiment, a signal processor can be disposed within the handle portion and coupled to the connector. The signal processor can be configured to monitor the at least one physiological parameter and to communicate to a user when the parameter falls outside of a preset range.

In another embodiment, a surgical system for manipulating tissue within a body is provided and includes a handle having an elongate shaft extending distally therefrom. The system can include a support ring coupled to a distal end of the elongate shaft. The system can also have a plurality of blades removably mated to the support ring and configured to retract tissue. An illumination source can be disposed on at least one of the elongate shaft and the support ring and the illumination source can be configured to illuminate tissue being retracted. The system can include a sensor disposed on at least one of the elongate shaft, the support ring, and the plurality of blades and configured to monitor at least one physiological parameter of a body tissue. In one embodiment, the plurality of blades can be configured to snap-fit onto the support ring.

A surgical kit is also provided. In one embodiment, the kit can include at least one retractor having a proximal end, a distal end, and an illumination source to illuminate an area surrounding the distal end. The distal end can have a blunt dissecting tip and a sensor disposed thereon to monitor at least one physiological parameter of a body tissue. The kit can also include at least one modular tip configured to be disposed over the blunt dissecting tip of the at least one retractor, and at least one support ring configured to support the retractor at the proximal end of the retractor when the retractor is disposed within the body.

DETAILED DESCRIPTION

Minimally invasive surgical procedures have been developed to minimize the risk of trauma to surrounding tissue during surgical procedures. For example, lateral approach thoracic surgery is now a common method of performing spinal surgery. However, in performing minimally invasive surgeries, visibility of the surgical field is significantly reduced, thus leading to an increased risk of traumatic contact with neural tissue. Thus, to safely and reliably perform surgical procedures, such as lateral approach thoracic procedures, increased fields of vision and monitoring capabilities are necessary.

The present invention relates to methods and devices for surgically manipulating tissue, such as muscle fibers including embedded neural tissue within a deep access portal in a body. In general, the methods and devices include an elongate retractor shaft having a distal retractor tip that is configured to manipulate tissue, for example the tip can be configured to separate muscle and nerve fibers surrounding a vertebra. The elongate retractor shaft can include an illumination source such that at least a portion of the surgical field is illuminated by the device when the device is used in the body. A sensor can also or alternatively be included on the elongate retractor shaft, for example on the blunt retraction tip, such that the sensor can monitor physiological parameters of the tissue in or adjacent to the surgical field. The device can include various features to allow for mating with support structures, retraction of tissue, modularity, etc., exemplary embodiments of which are discussed in detail below. A person skilled in the art will appreciate that a device can have any combination of features disclosed herein. The devices disclosed herein can also be configured for use in any procedure in which it is necessary to manipulate tissue, including both open surgery and minimally invasive procedures. In certain exemplary embodiments, the methods and devices disclosed herein can be particularly useful in minimally invasive procedures where access to the surgical field is through a small portal or cannula with limited vision. As mentioned, one such use is in spinal surgeries, such as minimally invasive lateral approach thoracic procedures.

FIGS. 1A and 1Billustrate one embodiment of the surgical retraction device100. As shown, the surgical retraction device100is in the form of a generally elongate retraction shaft112having a proximal end114and a distal end116. The proximal end114can include a handle portion118configured to be grasped by a user, and the distal end116can include a tissue retraction tip120. An illumination source122can be disposed on the elongate retraction shaft112for illuminating tissue surrounding the device. The device100can also include a sensor126disposed thereon and configured to monitor physiological parameters, e.g., neural and myo monitoring, temperature, pressure, and blood oxygen levels, of the tissue contacted by the tip. A connector128can be coupled to the proximal end114of the device and it can be electrically or fiber optically coupled to at least one of the illumination source122and the sensor126. In some embodiments, the connector128can be formable to hold the retractor in place.

As indicated above, the proximal end114of the elongate retraction shaft112can include a handle portion118that is configured to be grasped by a surgeon. The handle portion118can have any shape and size, and it can merely be a portion of the shaft configured to be grasped. In the illustrated embodiment, the handle portion118includes gripping features, which can be in the form of one or more ridges or surface protrusions extending around the shaft, to facilitate grasping by a user. The ridges can also facilitate mating of the device to a support member, such as a snap-fitting on a support ring. In other embodiments, a handle can be formed on or coupled to the shaft and it can have an ergonomic shape designed to allow a user to grip the device100comfortably while allowing for optimum manipulation of the blunt retraction tip120. While not shown inFIG. 1A, the handle portion118can also include features for facilitating mating to another device, such as a support ring, wrench, or a robotic arm. For example, the handle portion118can include a central aperture that allows for attachment to a mechanical arm or device.

The handle portion118can also include a variety of other features, such as a display for communicating sensed physiological parameters of the tissue being manipulated, or for displaying tissue imaged by a distal end of the device. In other embodiments, the handle portion118can be configured to couple to various external devices, such as an image guidance system or an external power supply. In another embodiment, the handle portion118can house an internal power supply, such as a battery, and any electrical circuitry required to control and power the illumination source122and/or the sensor126. For example, the circuitry can include an internal signal processor for monitoring the sensor126signal. While not shown, the handle portion118can also include a switch for allowing a user to activate at least one of the illumination source and the sensor. Various switches known in the art can be used.

The elongate shaft112extends distally from the handle portion118and is preferably dimensioned so as to allow the distal end116of the elongate retraction shaft to be disposed within a body cavity for manipulating tissue, while the proximal end114is positioned outside of the patient's body for allowing the handle portion118to be grasped by a user. While the length can vary depending on the intended use, in one embodiment the length of the elongate shaft112can be in the range of about 30 mm to about 200 mm. The diameter of the shaft, as well as the diameter of the handle portion118, can vary depending on the intended use, and the shaft and handle can have the same or different diameters. In one embodiment, the handle portion118can have a diameter that is greater than a diameter of the shaft112to facilitate gripping of the device. By way of non-limiting example, the diameter of the handle can be in the range of about 5 mm to about 25 mm, and the diameter of the shaft can be in the range of about 3 mm to about 12 mm. The shaft112can also be generally rigid and linear, extending along a single longitudinal axis, or in other embodiments the shaft can be non-linear and/or flexible or malleable.

As indicated above, the retraction tip120is formed on the distal end116of the elongate shaft112. The retraction tip120can have various configurations for manipulating tissue in the body, and the particular configuration can depend on the intended use. For example, the retraction tip120can be in the form of a blunt tip configured to allow a surgeon to separate muscle and neural fibers near the spinal column and to retract and retain the tissue out of the surgical field giving access to vertebral bone tissue under the retracted muscle and neural tissue, such as a Penfield dissector as known in the art. In the illustrated embodiment, the retraction tip120can have a generally flattened configuration such that a width extending in a first direction perpendicular to a longitudinal axis of the shaft is greater than a depth extending in a second opposite direction perpendicular to the longitudinal axis. The generally flattened tip can have a distal-most portion with a reduced diameter so as to form a pointed cylindrical tip portion121. In other embodiments, however, the retraction tip can be cylindrical, concave along any one or more surfaces, rectangular, spherical, etc. The tip can include a groove or central lumen to aid in the positioning of additional tools such as a surgical wire or a fixation pin. The tip can be sufficiently narrow to penetrate and anchor in a bone surface with the aid of a surgeon or it can be anchored with a screw or pin. The central lumen can also be used to provide aspiration when a vacuum source is connected to the handle118. Additionally, the blunt retraction tip120can be configured to removably mate to the elongate shaft and a plurality of modular tips having various shapes and sizes can be provided, as will be discussed in detail below.

As mentioned above, the retractor100can also include an illumination source122for illuminating tissue surrounding the distal retraction tip120. The illumination source can include a plurality of light sources, for example two light emitting diodes. Alternatively, the illumination source can be a singular light source. The illumination source can produce a diffuse light field radiating from the light source so as to light the general working area. Alternatively, the illumination source can be configured to produce a targeted light field that shines directly onto a desired area, for example the illumination source can be directed to shine toward the cylindrical tip portion121of the retractor100. In some embodiments, the targeted light field is the result of divergent or convergent configuration of the illumination sources balancing the light about the tip portion and the adjacent tissue. The illumination source can be any known light source that is capable of providing illumination to a cavity. For example, the illumination source can be a light emitting diode, an organic light emitting diode, a fiber optic lighting system such as those including polymeric light pipes, and/or chemical luminescent strips.

The illumination source can be disposed at any location along the elongate shaft112such that when the device is disposed within a patient's body, e.g., within a deep access portal, the illumination source will illuminate at least a portion of the surgical field, such as tissue surrounding a vertebra. The location of the illumination source can vary depending on the quantity of illumination sources as well as the intended use. In the embodiment shown inFIG. 1A, the illumination source122is positioned proximally adjacent to the distal end116, and more particularly proximal to the cylindrical tip portion121. This will allow the illumination source122to illuminate tissue being manipulated by the retraction tip120. A person skilled in the art will appreciate that the illumination source122can be positioned at any location along the length of the shaft112, including along the handle portion118or at the cylindrical tip portion121. Moreover, the device100can include multiple illumination sources. In certain exemplary embodiments, the illumination source122is positioned a distance from the distal-most end of the shaft122that is in the range of about 10 mm to about 100 mm.

The illumination source can be coupled to the retractor device100using a variety of techniques. In the illustrated embodiment, the illumination source122is in the form of a light emitting diode that is disposed within a bore123formed in the shaft112. While not shown, the bore can extend into an inner lumen that extends through the shaft112for allowing the illumination source122to be coupled to a power source disposed within the handle, or through an electrical connector128extending from a proximal end of the handle portion118. In some embodiments, the illumination source122can be fiber optically connected with connector128.

As indicated above, the device100can also include a sensor for sensing one or more physiological parameters of tissue being manipulated by the retraction tip120.FIG. 1Billustrates the retraction tip120of the device100in more detail. While the sensor126can be positioned at various locations along the shaft112, in the illustrated embodiment the sensor126is disposed on an external surface and extends longitudinally along the retraction tip120such that the sensor126will come into contact with tissue being manipulated. The sensor126can be disposed on the same side or on an opposite side of the shaft112as the illumination source122. The sensor126can be mated to the retraction tip120for instance by laminating the sensor126to the distal end116. Alternatively, the sensor126can be disposed within a bore or lumen in the blunt retraction tip120, or a portion of the tip itself can configured to function as a sensor, for example surfaces of the retraction tip120can function as a thermocouple to measure temperature. In some embodiments, the retraction tip120can include a single sensor to monitor a single parameter, multiple sensors for monitoring a number of different parameters, or a single sensor that can monitor more than one parameter. In use, the sensor(s) can be configuration to measure a variety of physiological parameters, as will be discussed in more detail below.

FIG. 2illustrates another embodiment of a tissue retractor200, which can be similar to the retractor100ofFIG. 1, but which has a non-linear shaft210. As shown, the retractor200generally includes a handle portion212at a proximal end214of the shaft212and a retractor tip216at a distal end216of the shaft. The retractor200also includes an illumination source222disposed on the shaft212at a location proximally adjacent to the distal retractor tip226. While not shown, the retractor can further include a sensor, as discussed above with respect toFIG. 1.

As indicated above, in this embodiment the retractor shaft212is non-linear. While the non-linear shape can vary and the shaft212can include any number of bends or curves formed therein, in the illustrated embodiment the shaft includes an S-shaped bend224formed at a general mid-portion thereof. This S-shaped bend224preserves a surgeon's line of sight to the tip216by having the handle portion212extend along a longitudinal axis Ahthat is offset from along a longitudinal axis Atof the portion containing the retractor tip226. The surgeon's view is thus unobstructed by the surgeon's hands or other support structure supporting the handle portion218. The elongate retractor shaft can optionally be malleable such that the location of any bends can be adjusted and the shaft can be oriented in a desired configuration. In other embodiments, the shaft can be formed from a shape-memory material such that the curvature changes in response to change in temperature or other outside stimulus.

FIG. 3illustrates another embodiment of a tissue retractor300having a handle portion318and a non-linear elongate retractor shaft312extending distally from the handle318. In this embodiment, the handle318is shown having a switch316, a power source332, a signal processor330, and a connector329extending between the signal processor330and a sensor326located in the retraction tip320, and more particularly in the distal-most tip321. The power source332can be in the form of a battery and the switch316can be coupled to the battery and to the signal processor330. As a result, when the switch316is activated, power is delivered from the power source332to the signal processor330, which in turn sends a signal through the connector329to at least one of the sensor326and first and second illumination sources322a,322b.FIG. 3furthers illustrates an L-shaped bend324formed at a substantial mid-portion of the shaft312between proximal and distal ends314,316thereof. As a result, a longitudinal axis through the retraction tip320is substantially transverse to a longitudinal axis through the handle portion318.

FIG. 4illustrates a distal portion of another embodiment of an elongate retractor shaft400having a first aperture410and a second aperture412formed in the retractor shaft through which first and second illumination sources (not shown) can be at least partially disposed. As further shown inFIG. 4, the shaft400can include an inner lumen413extending therethrough for receiving one or more electrical or fiber optic connectors (not shown) for connecting the illumination sources to a power source or fiber optic system. In this embodiment, the apertures410,412are formed in a first surface414having a substantially convex shape, and the retraction shaft400includes a second, opposite surface416that is substantially concave. The illumination sources can be seated within the apertures410,412and retained therein using various techniques, such as threads, adhesives, welding, etc. Alternatively, the illumination source can be laminated onto an outer surface414,416of the elongate retraction shaft.

FIG. 5illustrates a distal portion of another embodiment of an elongate retractor shaft500having a first aperture510and a second aperture512formed in a first substantially convex surface518of the retractor shaft500. The first and second apertures512can be configured to seat first and second illumination sources (not shown). In some embodiments, the retractor500can have another, third aperture514on a second or opposite substantially concave surface516. One or more additional illumination sources can be disposed within the third aperture514for illuminating tissue in a direction opposite to the direction of illumination provided by the illumination sources disposed within the first and second apertures510,512. As with the previous embodiment, the elongate shaft500can include a lumen522extending therethrough and configured to provide access, e.g., for one or more electrical or fiber optic connectors, from a proximal end (not shown) of the shaft500to the apertures510,512,514.

As indicated above, in some embodiments, such as those shown inFIGS. 4 and 5, the lumen413,522extending therethrough can house an electrical coupling for the illumination source. Additionally or alternatively, the lumen413,522can house a fiber optic coupling for the illumination source. The lumen can extend from the proximal end of the elongate shaft to the distal end, or can only extend through a portion of the shaft, e.g., terminating proximal to the distal-most end. The lumen can be so dimensioned as to allow an electrical or fiber optic coupling to extend from the proximal end of the shaft to the illumination source, the sensor, or both. Additionally, the shaft can have more than one lumen, for instance the shaft can include a first lumen housing a first electrical coupling and a second lumen designed to deliver surgical accessories or tools, such as bone screws, to the surgical field (not shown). Additionally, the second lumen can also be configured to provide aspiration with a vacuum system. The electrical coupling can be any known coupling mechanism, such as a conductive wire.

FIG. 6illustrates an exemplary circuit600to power first and second illumination sources610,610′. The illumination sources610,610′ can be powered by an internal power source612. The power source612can be disposed on or within the device, for instance in a cavity within the handle (for example inFIG. 3, power source332is disposed within handle312). Alternatively, the power source612can be external to the device and electrically connected to the proximal end of the handle through a connector, such as an electrical cord or cable as shown inFIG. 1. The power source612can include a battery or series of batteries as is known in the art or can include any other known power source, such as a standard wall outlet.

As shown inFIG. 6, the power source612can be electrically coupled to the illumination sources610,610′ by a circuit600that includes a switch614and a fuse or diode616. The switch614can be configured to control power to the illumination source610,610′ such that a user can control the optical output of the illumination source610,610′. The switch614can be any mechanism capable of controlling power to the illumination source610,610′, including on/off switches or dimmer-type switches to give a range of light outputs. In one embodiment, the switch614can be a physical switch disposed on the handle that is configured to be manipulated by a surgeon. For example, the switch614can be a touch-sensitive surface that is toggled as a surgeon touches any portion of the surface of the handle (for example, the switch316inFIG. 3). In other embodiments, the switch614can be a depressible button-type switch disposed on the handle. In some embodiments, the switch614can be a one-way on switch that is activated as soon as the device is removed from a sterile package (not shown).

FIGS. 7A-7Dillustrate various types of exemplary sensors for use on any of the retraction tips disclosed herein. The sensor can be configured to measure any parameter that has physiological significance to one skilled in the art. For example, the physiological parameters monitored by exemplary sensors can include temperature, pressure, blood oxygen levels, and electrical conductivity. As shown inFIG. 7A, the sensor810is in the form of a lab-on-a-chip sensor810that is disposed on a retractor tip800having a generally concave distal-facing surface so as to conform to bone820as shown. The lab-on-a-chip sensor can be as small as a few millimeters and can utilize micro fluidics to analyze physiological parameters of the adjacent tissue. For example, a lab-on-a-chip sensor can monitor the blood oxygen levels in the adjacent tissue.FIG. 7Billustrates another tip900having a concave surface that conforms to a surface of a bone920. The sensor910in this embodiment is a pressure sensor910for sensing applied pressure. The pressure sensor can be any type of pressure sensor known in the art, for example a force sensing resistor, resistive strain gauge, dielectric pressure sensitive film, piezoelectric type sensor, capacitive, electromagnetic, potentiomatic, resonant, and thermal type pressure sensors. In another embodiment, shown inFIG. 7C, tip1000includes a temperature sensor1010, such as a thermocouple. As with the tips shown inFIGS. 7A and 7C, tip1000includes a distal-facing concave surface configured to conform to bone1020.FIG. 7Dillustrates yet another embodiment of a tip1100that is configured to have a concave surface that conforms to a surface of a bone1120. In this embodiment, the sensor is in the form of an electrical conductivity meter1110, such as that commonly used in neural and myo monitoring systems.

The various sensors disclosed herein can be configured to monitor real-time data during a surgical process and can be coupled to computational devices such that a surgeon can be alerted if the monitored parameter is outside of a preset range. Computational devices can include known patient monitoring systems that are in an operating room or procedure room, or alternatively or additionally can include a signal processor and computational device stored directly in the elongate retraction shaft of a retractor device. If stored directly in the shaft, the computational device or signal processor can be disposed anywhere in the shaft (for example, as shown inFIG. 3, the signal processor330is disposed within the handle318adjacent the power source332).

The sensor(s) can be in communication with neural and myo monitoring systems known in the art. For example, the sensor(s) can be configured to monitor conductivity of the contacted tissue in order to sense when neural tissue is near and/or when the adjacent neural tissue is active. The sensor(s) can be coupled to the illumination source coupled to the shaft for illuminating tissue, or to a separate illumination source or other indicator provided elsewhere on the device, e.g., on the handle. When a parameter monitored by the sensor is outside of a preset range, the illumination source can alert the surgeon, for instance by flashing, blinking, turning off, or changing color when the temperature of the tissue is outside of a desired range. To achieve this communication between the sensor and the illumination source, the sensor and illumination source can be electrically coupled in a circuit that is housed within the device, or that includes components that are external to the device (such as an external signal processor).

FIGS. 8A-8Cillustrate another embodiment of a tissue retractor. The retractor1200can include a handle1210and an elongate shaft1220extending distally from the handle1210. The system1200can also include a support ring1230coupled to a distal end1222of the elongate shaft. The support ring1230can be configured to removably mate to a plurality of blades1240. As shown, the ring1230can have an oblong or oval shape. Alternatively, the ring can have a circle, pentagon, octagon, or any other geometric shape. One or more blades1240can be mated to the support ring1230to retract tissue surrounding the blades1240.

FIG. 8Billustrates one of the removable blades1240in more detail. The blade1240can have proximal and distal ends1242,1244. The distal end1244can be configured to be disposed in and to retract tissue. The proximal end1242can be configured to snap into the support ring1230. While the blades1240can be removably attached to the ring1230using various techniques, in one embodiment a snap-fit engagement can be utilized. For example, the blade can include an elongate surface protrusion (not shown) extending laterally across a proximal end1242thereof, and the ring1230can include an elongate groove (not shown) that is configured to seat and engage the protrusion on the blade1240.

FIG. 8Bfurther illustrates an insertion handle1250that can be connected to the proximal end1242of the blade1240and that can be manipulated to twist the blade1240into engagement within the ring1230. Such a configuration can allow the blades1240to be attached to the ring1230intraoperatively. As further shown inFIG. 8A, the blade1240can have an aperture1246form on an inwardly facing surface thereof that can be designed to receive a bone anchor or other surgical implement.

FIG. 8Cillustrates the exemplary retractor1200having three blades1240,1240′,1240″ snapped into place in the support ring1230in a configuration that will retract tissue and define a deep access portal or cavity in tissue. As shown, the ring1230need not have blades1240,1240′,1240″ mated in a full circle around the ring1230, rather, a portion of the ring1230can be free of blades1240as shown. Additionally, any one or more of the ring1230, the blades1240,1240′,1240″, and elongate shaft1220can include an illumination source disposed thereon or therein to illuminate the deep access portal or cavity created by the system, and/or a sensor as described herein to monitor at least one parameter of the retracted tissue.

FIG. 9illustrates an exemplary surgical kit1500for retracting tissue. An exemplary kit1500can include any tools necessary for performing any type of surgery, such as spinal surgery, and in particular thoracic surgery. As shown, the kit1500can include a combination of devices, such as illuminating retractors1510,1520,1530,1540,1550. With reference to retractor1510, each illuminating retractor can have a proximal end1560, a distal end1570, and an elongate intermediate portion1580. The distal end1570can have a retraction tip1590and a sensor (not shown) disposed thereon to monitor at least one physiological parameter of a body tissue. The elongate intermediate portion1580can include an illumination source1592as described herein to illuminate an area surrounding the distal end. A person skilled in the art will appreciate that the kit can include any combination of retractors having any combination of features disclosed herein.

The kit can also include one or more modular tips1594configured to be removably disposed over any one of the blunt retracting tips on retractors1510,1520,1530,1540,1550. Each modular tip can be in the form of a cap having a shape that is different from the shape of the other modular tips and the shape of the retractor tips so as to allow the tip of the retractor to be modified as may be desired based on the intended use. The tips can be of a different material such as absorptive polymer/sponge/cloth1594. This can allow the retractor blade to perform various other functions, such as the function of a Kittner dissector. The kit can further include at least one support ring1596configured to support one or more of the retractors1510,1520,1530,1540,1550at the proximal end of a retractor when the retractor1510,1520,1530,1540,1550is disposed within the body. For example, proximal end1560of retractor1510can be configured to mate to the support ring1596. Some of the retractors, e.g., retractors1540and1550, can include a malleable connector1598extending from a proximal end thereof that is configured to be wrapped around the ring for mating the retractor to the support ring.

A person skilled in the art will appreciate that the systems and devices disclosed herein can be formed of any known biologically compatible material that is suitable for the given component's described properties, function, and design. For example, the elongate retraction shaft, support ring, and blades can be formed of any biocompatible rigid or semi-rigid material, such as stainless steel, nitinol, platinum, tungsten, polytetrafluorethylene (PTFE), polyamides, polyethers, polyurethanes, polyvinylchloride, silicones, and various other metals, metal alloys, polymers, and copolymers known to those skilled in the art to have the desired mechanical properties. The blunt retraction tip can be formed from the same or different materials as the elongate retraction shaft and can include various coatings to provide additional beneficial material properties. For example, the tip can have a low-durometer coating, such as silicone or Teflon. The handle can also have a coating thereon, for instance a non-conductive, non-slip coating such as rubber or silicone.

FIG. 10illustrates one exemplary use of a tissue retractor. In this embodiment, two retractors1610,1610′ are placed within a deep access portal1612in a body and are configured to manipulate tissue. Manipulating tissue can include separating, retracting, distracting, dilating, or otherwise moving tissue within the body. Manipulating can also include cutting or severing tissue, such as with a beveled knife blade (not shown), or alternatively can include retracting and distracting tissue without cutting the tissue, for example with a blunt retraction tip1614,1614′. The devices can hold muscle1616and nerve fibers1618away from the portal1612thus giving access to the underlying bone1620and preventing the sensitive neural1618and muscular tissues1616from being unnecessarily contacted during procedures involving the bone.

The devices1610,1610′ are shown in cut-away with the internally powered handles and surgeon's hands represented by1626and1626′. Alternatively the devices can include connectors1622,1622′ extending from a proximal end1624,1624′ of the devices1610,1610′. The connectors can be coupled to an external power supply or signal processor in the location of1626,1626′. The external power supply or signal processor1626can be configured to power or otherwise communicate with the illumination sources1628,1628′ and/or with one or more sensors (not shown) disposed on the devices1610,1610′.

FIG. 11illustrates another embodiment of a retractor1710disposed within a cannula1712defining an access portal through tissue. The surgical field1714can be the area near the thoracic region of the spinal column1716that is dense with nerve fibers. A distal tip1718of the retractor1710can be used to retract tissue to form a cavity giving access to the surgical field1714. The retractor can include a connector1720extending from the proximal end1722of the retractor1710that includes a handle portion1724.

FIG. 12illustrates retractors1800,1800′ disposed in a deep access portal1802with connectors1810,1810′ extending from a proximal portion1812,1812′ of the elongate retraction shafts1814,1814′. The connectors1810,1810′ can be configured to be operatively coupled, i.e., electrically, optically, and/or physically, to the proximal end1812,1812′ of the elongate retractor shafts1814,1814′. The connectors1810,1810′ can be configured to electrically connect at least one of the illumination source1816,1816′ and a sensor (not shown) to an external signal processor such as a myo monitor. All or a portion of each connector1810,1810′ can also be malleable1818,1818′ to allow the connectors to wrap around and mate to a support structure1820.

FIG. 13illustrates another embodiment showing malleable connectors1910,1910′ on two retractors1900,1900′ tied or otherwise coupled to one another such that when the retractors1900,1900′ disposed within a body1920, they are maintained in a stable position. As with the previous embodiment, the connectors1910,1910′ can be formed of any known articulatable and/or malleable wire or sheath. For example, the connectors1910,1910′ can be a segmented, articulatable sheath with a conductive wire or fiber optic cable running therethrough to electrically or fiber optically connect the device to an external system. The connectors1910,1910′ can thus mate to the proximal end1930,1930′ of the retractors1900,1900′ and can extend through a lumen in the device to make an electrical connection with at least one of the illumination source and the sensor.