BACKGROUND 
       [0001]    The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 62/301,255, filed on Feb. 29, 2016, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates generally to microwave catheters, and, more particularly, to a 90-degree interlocking geometry for an introducer used to facilitate deployment of a microwave radiating catheter. 
         [0004]    2. Discussion of Related Art 
         [0005]    Electromagnetic fields can be used to heat and destroy tumor cells. Treatment may involve inserting ablation probes into tissues where cancerous tumors have been identified. Once the ablation probes are properly positioned, the ablation probes induce electromagnetic fields within the tissue surrounding the ablation probes. 
         [0006]    In the treatment of diseases such as cancer, certain types of tumor cells have been found to denature at elevated temperatures that are slightly lower than temperatures normally injurious to healthy cells. Known treatment methods, such as hyperthermia therapy, heat diseased cells to temperatures above 41° C. while maintaining adjacent healthy cells below the temperature at which irreversible cell destruction occurs. These methods involve applying electromagnetic fields to heat or ablate tissue. 
         [0007]    Devices utilizing electromagnetic fields have been developed for a variety of uses and applications. Typically, apparatuses for use in ablation procedures include a power generation source, e.g., a microwave generator that functions as an energy source and a surgical instrument (e.g., microwave ablation probe having an antenna assembly) for directing energy to the target tissue. The generator and surgical instrument are typically operatively coupled by a cable assembly having a plurality of conductors for transmitting energy from the generator to the instrument, and for communicating control, feedback, and identification signals between the instrument and the generator. 
         [0008]    There are several types of microwave probes in use, e.g., monopole, dipole, and helical, which may be used in tissue ablation applications. The heating of tissue for thermal ablation is accomplished through a variety of approaches, including conduction of heat from an applied surface or element, ionic agitation by electrical current flowing from an electrode to a ground pad (current-based technology), optical wavelength absorption, or, in the case of microwave ablation, by dielectric relaxation of water molecules within an antenna electromagnetic field (field-based technology). 
         [0009]    Because of the various components needed in a microwave ablation assembly, the weight of the microwave ablation assembly is increased, thus causing difficultly in handling of such assembly. The weight of the microwave ablation assembly may limit the surgeon&#39;s capability of using surgical tools simultaneously with the microwave ablation assembly, as well as causing fatigue on the hands and arms of the surgeon when performing minimally-invasive procedures. Accordingly, there is a need for an apparatus that would facilitate one-handed actuation and manipulation of the catheter and surgical instrument leaving one hand to perform other tasks, as well as for an apparatus that would limit the number of steps required, as each step causes movement of the catheter within the patient. 
       SUMMARY 
       [0010]    One aspect of the present disclosure is directed to a microwave ablation assembly including a first cannula, a trocar insertable through the first cannula and configured to facilitate insertion of the first cannula into a target tissue, and a microwave antenna assembly configured to interlock with the first cannula. The microwave antenna assembly includes a coaxial feedline having a radiating section formed thereon, the microwave antenna assembly configured to be inserted into the first cannula. The microwave ablation assembly further includes an actuator operatively connected to one of the first cannula or microwave antenna assembly, where operation of the actuator between a first position and a second position exposes the radiating section of the microwave antenna assembly from a distal portion of the first cannula. 
         [0011]    The microwave ablation assembly may include a transition head adapted to connect the microwave antenna assembly to a microwave transmission cable assembly. Additionally the microwave ablation assembly may include a multi-lumen housing having a hub formed at a proximal end thereof, the hub defining a longitudinal axis there through, and including an inflow port and an outflow port to provide respective ingress and egress of a coolant to and from the multi-lumen housing for cooling the microwave antenna assembly. 
         [0012]    The microwave ablation assembly may include a second cannula extending from the multi-lumen housing, in fluid communication with the inflow and outflow ports, and receiving the microwave antenna assembly, wherein coolant flows through the second cannula and over the microwave antenna assembly. 
         [0013]    In accordance with a further aspect of the disclosure, the inflow port and the outflow port are parallel to each other, and perpendicular to the longitudinal axis defined by the hub. Further, the transition head may include a first section and a second section, the first section adapted to be coupled to a distal end of a microwave transmission cable assembly and the second section adapted to be coupled to a proximal end of the coaxial feed line. Still further, the microwave ablation assembly may include an o-ring adapted to fit on the second section of the transition head which is adapted to be received within the hub of the multi-lumen housing such that the o-ring forms a fluid tight seal between the second section of the transition head and the hub upon connection. 
         [0014]    In accordance with a further aspect of the disclosure, the actuator defines a pair of recesses on opposed surfaces thereof, and an opening for exposing the inflow port, the outflow port, and the distal end of the cable assembly. Pins may be received in the pair of recesses on opposed surfaces of the actuator. Further, a locking spindle may be incorporated where the locking spindle is assembled over the actuator. The locking spindle may include a body portion defining a pair of longitudinal slots on opposed surfaces thereof, where the longitudinal slots each separate a first end from a second end. 
         [0015]    In a further aspect of the disclosure, the actuator may include a sliding spindle which is configured to slide within the locking spindle such that the pins travel along the pair of longitudinal slots to lock between the first ends and the second ends. The actuator may include a control ring assembled over a portion of the locking spindle and the sliding spindle. The control ring may include a body portion, a pair of opposed projections extending from the body portion, and a pair of opposed elongated camming surfaces configured and dimensioned to receive the pins and guide longitudinal movement thereof. 
         [0016]    A nose cone may be assembled over a portion of the control ring, the nose cone having a proximal end and a distal end, the distal end having a tip portion with a locking mechanism, and the proximal end defining a cut-out portion configured to receive the outflow port there through. The locking spindle may include a retaining ring configured to secure the nose cone to the locking spindle. A housing formed on a proximal region of the first cannula may be configured to mate with the locking mechanism of the nose cone. 
         [0017]    In accordance with aspects of the present disclosure, upon actuation of the actuator the sliding spindle and second cannula remain stationary and the first cannula is drawn in the direction of the sliding spindle to expose the second cannula and the radiating section of the microwave antenna assembly located therein. Additionally or alternatively, the locking spindle, the control ring, and the nose cone may be drawn in the direction of the sliding spindle to expose the second cannula and the radiating section of the microwave antenna assembly located therein. 
         [0018]    Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Various aspects of the present disclosure are described hereinbelow with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein: 
           [0020]      FIG. 1  is a perspective view of a microwave transmission and radiation component, in accordance with aspects of the present disclosure; 
           [0021]      FIG. 2  is a perspective view of a transmission head of the microwave transmission and radiation component of  FIG. 1 , in accordance with aspects of the present disclosure; 
           [0022]      FIG. 3  is a cross-sectional view of a multi-lumen overmolded fluid hub, in accordance with aspects of the present disclosure; 
           [0023]      FIG. 4  is a perspective view of a coaxial feedline having a microwave radiating section of  FIG. 1  inserted through the multi-lumen overmolded fluid hub of  FIG. 3 , in accordance with aspects of the present disclosure; 
           [0024]      FIG. 5  is a cross-sectional view of the coaxial feedline having the microwave radiating section of  FIG. 1  inserted into the multi-lumen overmolded fluid hub of  FIG. 3 , in accordance with aspects of the present disclosure; 
           [0025]      FIG. 6  is a perspective view of a sliding spindle, in accordance with aspects of the present disclosure; 
           [0026]      FIG. 7  is a cross-sectional view of the sliding spindle of  FIG. 6  assembled onto at least the multi-lumen overmolded fluid hub of  FIG. 3 , in accordance with aspects of the present disclosure; 
           [0027]      FIG. 8  is a perspective view of the sliding spindle of  FIG. 6  assembled onto the microwave transmission and radiation component of  FIG. 1 , in accordance with aspects of the present disclosure; 
           [0028]      FIG. 9  is an enlarged view of the sliding spindle of  FIG. 6  depicting a recess for receiving a pin, in accordance with aspects of the present disclosure; 
           [0029]      FIG. 10  is a perspective view of a pair of pins inserted into recesses of the sliding spindle of  FIG. 6 , in accordance with aspects of the present disclosure; 
           [0030]      FIG. 11  is an enlarged view of the sliding spindle of  FIG. 6  depicting the pair of pins of  FIG. 10  inserted thereto, in accordance with aspects of the present disclosure; 
           [0031]      FIG. 12  is a perspective view of a locking spindle, in accordance with aspects of the present disclosure; 
           [0032]      FIG. 13  is an enlarged view of the locking spindle of  FIG. 12  assembled onto the sliding spindle of  FIG. 6 , in accordance with aspects of the present disclosure; 
           [0033]      FIG. 14A  is a perspective view of a first embodiment of a control ring, in accordance with aspects of the present disclosure; 
           [0034]      FIG. 14B  is a perspective view of a second embodiment of a control ring, in accordance with aspects of the present disclosure; 
           [0035]      FIG. 15A  is a cross-sectional view of the control ring of  FIG. 14A  assembled onto the locking spindle of  FIG. 12 , where the control ring is in a first or deployed position, in accordance with aspects of the present disclosure; 
           [0036]      FIG. 15B  is a cross-sectional view of the control ring of  FIG. 14A  assembled onto the locking spindle of  FIG. 12 , where the control ring is in a second or retracted position, in accordance with aspects of the present disclosure; 
           [0037]      FIG. 16A  is a cross-sectional view of the control ring of  FIG. 14A  assembled onto the locking spindle of  FIG. 12 , where the control ring is in the second position, in accordance with aspects of the present disclosure; 
           [0038]      FIG. 16B  is a cross-sectional view of the control ring of  FIG. 14A  assembled onto the locking spindle of  FIG. 12 , where the control ring is in the first position, in accordance with aspects of the present disclosure; 
           [0039]      FIG. 17  is an enlarged view of the control ring assembled onto the locking spindle, the locking spindle assembled onto the sliding spindle, and the sliding spindle assembled onto the microwave transmission and radiation component, and depicting the inflow and outflow ports, in accordance with aspects of the present disclosure; 
           [0040]      FIG. 18  is a perspective view of a nose cone, in accordance with aspects of the present disclosure; 
           [0041]      FIG. 19  is a perspective view of the nose cone of  FIG. 18  assembled onto the control ring of  FIG. 14A , in accordance with aspects of the present disclosure; 
           [0042]      FIG. 20  is a cross-sectional view of a portion of the nose cone, the nose cone connected to a retaining ring of the locking spindle to secure the nose cone to the locking spindle, in accordance with aspects of the present disclosure; 
           [0043]      FIG. 21  is an enlarged view of the nose cone of  FIG. 18  illustrating a hinge component, in accordance with aspects of the present disclosure; 
           [0044]      FIG. 22  is a perspective view of a surgical system including a microwave catheter and an access channel device assembled in a manner described with reference to  FIGS. 1-20 , in accordance with aspects of the present disclosure; 
           [0045]      FIG. 23A  is a perspective view of a cannula, in accordance with aspects of the present disclosure; 
           [0046]      FIG. 23B  is a perspective view of a trocar, in accordance with aspects of the present disclosure; 
           [0047]      FIG. 23C  is a perspective view of the trocar of  FIG. 23B  being inserted within the cannula of  FIG. 23A , in accordance with aspects of the present disclosure; 
           [0048]      FIG. 23D  is a perspective view of the trocar of  FIG. 23B  fully inserted within the cannula of  FIG. 23A , in accordance with aspects of the present disclosure; and 
           [0049]      FIG. 24  is a perspective view of the cannula/trocar assembly of  FIG. 23D  mounted onto the nose cone of  FIG. 18  and the microwave radiation section of  FIG. 1 , in accordance with aspects of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0050]    The present disclosure is directed to a microwave catheter connected to an access channel device at a 90-degree angle or in a substantially perpendicular configuration. The 90-degree transition geometry is enabled by the use of a 90-degree transition head, as well as a multi-lumen overmolded fluid hub having an inflow port and an outflow port that may be substantially parallel to each other. The 90-degree connection or 90-degree interlocking geometry between the microwave catheter and the access channel device reduces the load or pressure applied to the surgeon&#39;s hands and arms when manipulating such devices. Additionally, the 90-degree connection or 90-degree interlocking geometry between the microwave catheter and the access channel device enables quick separation of the cannula from the trocar so that the access channel device can be easily placed at a target location. Moreover, the 90-degree connection or 90-degree interlocking geometry between the microwave catheter and the access channel device enables needle-like placement of an elongated non-rigid microwave radiation catheter into targeted tissue for thermal ablation during open, laparoscopic or transcutaneous procedures without a guide wire or pre-established access path. 
         [0051]    Embodiments of the microwave ablation systems and components are described with reference to the accompanying drawings. Like reference numerals may refer to similar or identical elements throughout the description of the figures. As shown in the drawings and as used in this description, the term “proximal” refers to that portion of the apparatus, or component of the apparatus, closer to the user and the term “distal” refers to that portion of the apparatus, or a component of the apparatus, farther from the user. 
         [0052]    This description may use the phrases “in an embodiment,” “in embodiments,” “in some embodiments,” or “in other embodiments,” which may each refer to one or more of the same or different embodiments in accordance with the present disclosure. 
         [0053]    As it is used in this description, “microwave” generally refers to electromagnetic waves in the frequency range of 300 megahertz (MHz) (3×10 8  cycles/second) to 300 gigahertz (GHz) (3×10 11  cycles/second). As it is used in this description, “ablation procedure” generally refers to any ablation procedure, such as, for example, microwave ablation, radiofrequency (RF) ablation, or microwave or RF ablation-assisted resection. As it is used in this description, “transmission line” generally refers to any transmission medium that can be used for the propagation of signals from one point to another. As it is used in this description, “fluid” generally refers to a liquid, a gas, or both. The term “coolant” may be used interchangeable with the term “fluid.” 
         [0054]    Reference will now be made in detail to embodiments of the present disclosure. While certain exemplary embodiments of the present disclosure will be described, it will be understood that it is not intended to limit the embodiments of the present disclosure to those described embodiments. To the contrary, reference to embodiments of the present disclosure is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the embodiments of the present disclosure as defined by the appended claims. 
         [0055]    Referring initially to  FIG. 1 , the microwave transmission and radiation component  100  includes a microwave transmission cable assembly  102  connected to a microwave antenna assembly  108  via a transition head  110 . The microwave antenna assembly  108  includes a feedline  106  and a radiating section  106   a  located at a distal portion thereof and in electrical communication with the coaxial feed line  106 . The transition head  110  may be referred to as a 90-degree transition head  110 . The microwave transmission cable assembly  102  has a proximal end  101  and a distal end  103 . The proximal end  101  may have a spring-biased coupling element  104 . The spring-biased coupling element  104  may be coupled to a housing  2212  ( FIG. 22 ) for connection to a microwave generator. The microwave antenna assembly  108  has a proximal end  105  and a distal end  107 . In some embodiments, the microwave transmission cable assembly  102  has a first diameter and the coaxial feed line  106  has a second diameter, the first diameter being greater than the second diameter. The transition head  110  allows for a 90-degree connection to be established between the microwave transmission cable assembly  102  and the coaxial feed line  106  of the microwave antenna assembly  108 , as described in detail below with reference to  FIG. 2 . 
         [0056]    As shown in  FIG. 2 , the transition head  110  is formed by a first section  111  and a second section  113 . The first and second sections  111 ,  113  are perpendicular to each other and form a 90-degree angle therebetween. The first and second sections  111 ,  113  form a 90-degree interlocking geometry. The first section  111  is coupled to the proximal end  105  of the coaxial feed line  106 . The second section  113  is coupled to the distal end  103  of the microwave transmission cable assembly  102  via a tubular member  118 . A 90-degree coaxial cable connector (not shown but incorporated into the transition head  110 ) enables electrical connection between the microwave transmission cable assembly  102  and the coaxial feed line  106 . The first section  111  further includes an o-ring  115  circumferentially positioned about a portion thereof. The o-ring  115  does not contact the second section  113 , but ensures a water tight seal when the transition head  110  is integrated with a multi-lumen hub as described below with respect to  FIG. 3 . 
         [0057]    As shown in  FIG. 3 , the multi-lumen hub  300  includes a body portion or hub  310 . The body portion  310  has a proximal end  301  and a distal end  303 . The body portion  310  defines an upper body portion  311  and a lower body portion  313 . The upper body portion  311  defines a chamber  312  and the lower body portion  313  houses a cannula  314 . The chamber  312  is in fluid communication with the cannula  314 . The cannula  314  defines a longitudinal axis “X” therethrough. 
         [0058]    The cannula  314  may be formed of a rigid or a flexible material. In certain embodiments a combination of rigid (e.g., steel or ceramic) and flexible (e.g., polymeric materials) may be employed. Further, the cannula  314  may be pre-curved or shaped to reach a desired location within the physiology of a patient. Still further, the cannula  314  may employ one or more pairs of steering wires, enabling the cannula to be articulated in one or more directions. The use of a flexible material enables the advancement and navigation of the cannula  314  for the proper placement of the radiating section  106   a  housed therein, as will be described herein below. 
         [0059]    The multi-lumen hub  300  includes an inflow port  320  and an outflow port  330 . The inflow port  320  may also be referred to as a fluid intake port and the outflow port  330  may also be referred to as a fluid return port. The inflow port  320  defines an inflow lumen  322  therethrough and the outflow port  330  defines an outflow lumen  332  therethrough. The inflow and outflow ports  320 ,  330  provide respective ingress and egress of a fluid or coolant to and from the body portion  310  of the multi-lumen hub  300  for cooling the coaxial feed line  106  and radiating section  106   a  of the microwave transmission and radiation component  100  of  FIG. 1 . 
         [0060]    The inflow port  320  is substantially parallel to the outflow port  330 . Thus, the inflow lumen  322  of the inflow port  320  is also substantially in parallel to the outflow lumen  332  of the outflow port  330 . The inflow and outflow ports  320 ,  330  may be substantially perpendicular to the longitudinal axis “X” defined by the cannula  314 . The inflow and outflow ports  320 ,  330  have substantially circular openings. However, one skilled in the art may contemplate various geometrical openings for inflow and outflow ports  320 ,  330 . The inflow port  320  cooperates with the upper body portion  311  of the body portion  310 , whereas the outflow port  330  cooperates with the lower body section  313  of the body portion  310 . The inflow port  320  is in fluid communication with the chamber  312 , whereas the outflow port  330  is in fluid communication with the cannula  314 . The cannula  314  extends beyond a distal end of the lower body portion  313  of the body portion  310 . The diameter of the inflow and outflow lumens  322 ,  332  are greater than the diameter of the cannula  314 . The diameter of the chamber  312  is greater than the diameter of the inflow and outflow ports  320 ,  330 . 
         [0061]    Referring to  FIG. 4 , the assembled view  400  of the microwave transmission and radiation component  100  and the multi-lumen overmolded fluid hub  300  is shown. The microwave transmission and radiation component  100  is inserted into the multi-lumen hub  300 . Cannula  314  receives the coaxial feed line  106  and radiating section  106   a  of the microwave transmission and radiation component  100 . The o-ring  115  ( FIG. 2 ) is positioned in chamber  312  ( FIG. 3 ) to secure the second section  113  of the transition head  110  adjacent the proximal end  301  of the multi-lumen hub  300  at a region  410 . 
         [0062]    The cannula  314  and the multi-lumen hub  300  define a longitudinal axis “X” therethrough. The microwave transmission cable assembly  102  defines a longitudinal axis “Y” extending therethrough. The longitudinal axis “X” is substantially perpendicular to the longitudinal axis “Y.” Thus, the multi-lumen hub  300  is assembled at a 90-degree angle with respect to the microwave transmission cable assembly  102 . As a result, the 90-degree interlocking geometry of the transition head  110  enables a 90-degree placement or positioning of the multi-lumen hub  300  with respect to the microwave transmission cable assembly  102 . 
         [0063]    Referring to  FIG. 5 , the first section  111  of the transition head  110  is inserted into or received within the chamber  312  of the body portion  310  of the multi-lumen hub  300 . The second section  113  of the transition head  110  is secured adjacent the proximal end  301  of the multi-lumen hub  300  at a region  410 . The second section  113  of the transition head  110  seals off the chamber  312  via the o-ring  115 . The o-ring  115  sits at the proximal end  301  of the upper body portion  311  and within the chamber  312 . The o-ring  115  circumferentially engages an inner surface of the chamber  312  to form a tight seal thereof. 
         [0064]    Additionally, the cross-sectional view  500  illustrates a connecting member  120  for coupling the end  118  of the microwave transmission cable assembly  102  to the coaxial feed line  106 . The connecting member  120  is fully positioned within the second section  113  of the transition head  110 . 
         [0065]    In  FIG. 5 , the inflow port  320  is substantially parallel to the outflow port  330 . The inflow and outflow ports  320 ,  330  may be substantially in parallel to the microwave transmission cable assembly  102 . Thus, the microwave transmission cable assembly  102 , the inflow port  320 , and the outflow port  330  are all substantially perpendicular to the multi-lumen hub  300  and with the coaxial feed line  106 . The coaxial feed line  106  extends the length of the cannula  314 . The cannula  314  is in fluid communication with both the inflow port  320  and the outflow port  330  such that a coolant flows along the coaxial feed line  106  and around the radiating section  106   a  formed on a distal portion of the coaxial feed line  106 . 
         [0066]    Referring to  FIG. 6 , an actuator is shown, such as for example, a sliding spindle  600  that includes a body portion  610  having a proximal portion  601  and a distal portion  603 . The proximal portion  601  defines, for example, a dome-shaped portion  612 . The body portion  610  further defines an opening  620 , as well as a pair of recesses  630 . The recesses  630  are positioned on opposed sides of the distal portion  603  of the body portion  610 . The recesses  630  are offset from the opening  620 . The offset may be a 90-degree offset. Each of the pair of recesses  630  includes an aperture  632 . The body portion  610  is defined by a first body section  614  and a second body section  616  which are joined to form the body portion  610 . The distal portion  603  of the sliding spindle  600  further defines an aperture  618 . The aperture  618  is configured to allow the coaxial cannula  314  to pass therethrough, as discussed below with reference to  FIG. 7 . 
         [0067]    The elongated body portion  610  of the sliding spindle  600  is assembled over the multi-lumen hub  300  and the transition head  110 . The second section  113  of the transition head  110 , the inflow port  320 , and the outflow port  330  extend through the opening  620  ( FIG. 6 ) of the body portion  610 . Both the first section  111  and the second section  113  of the transition head  110  are at least partially enclosed within the sliding spindle  600 . The dome-shaped portion  612  of the body portion  610  of the spindle  600  is secured adjacent the second section  113  of the transition head  110 . The cannula  314  of the multi-lumen hub  300  extends through the aperture  618  of the sliding spindle  600 . The cannula  314  defines a longitudinal axis “X” extending through the multi-lumen hub  300  and the sliding spindle  600 . 
         [0068]    Referring to  FIG. 8 , the assembled view  800  of the microwave transmission and radiation component  100  and the multi-lumen overmolded fluid hub  300  and the sliding spindle  600  is shown. The microwave transmission and radiation component  100  is inserted into the multi-lumen hub  300  such that the coaxial feed line  106  and radiating section  106   a  are received within the cannula  314 . Then the sliding spindle  600  is assembled over the multi-lumen hub  300 . The cannula  314  and the multi-lumen hub  300 , and the sliding spindle  600  define a longitudinal axis “X” therethrough. The microwave transmission cable assembly  102  defines a longitudinal axis “Y” extending therethrough. The longitudinal axis “X” is substantially perpendicular to the longitudinal axis “Y.” Thus, the sliding spindle  600  and the multi-lumen hub  300  are assembled at a 90-degree angle with respect to the microwave transmission cable assembly  102 . 
         [0069]    In  FIG. 9 , the recess  630  is a circular recess defined at the distal portion  603  of the body portion  610  of the sliding spindle  600 . In the embodiment depicted in  FIG. 9 , a similar recess  630  on the other side of the sliding spindle  600  is present (not shown). Therefore, a pair of recesses  630  are defined on diametrically opposed surfaces of the distal portion  603  of the body portion  610 . The recesses  630  are each configured to receive a pair of pins  1010 ,  1020  shown in  FIG. 10 . The first pin  1010  includes a first section  1011  and a second section  1013 . The second pin  1020  is similar to the first pin  1010 , but is shown in an inverted configuration with respect to the first pin  1010 . The second pin  1020  includes a first section  1021  and a second section  1023 . The second pin  1020  also includes a rod  1025  extending away from the first section  1021 . The first section  1021  defines an annular recess  1027  surrounding the rod  1025 . The rod  1025  is configured to be received within an aperture  632  of the recess  630  to secure the second pin  1020  to the recess  630  of the sliding spindle  600 . As can be appreciated, a spring (not shown) may be received in the annular recess  1027  to push the pins  1010  and  1020  away from the body portion  610  of the sliding spindle  600 , when the pins  1010 ,  1020  are received within the recesses  630 , as shown in  FIG. 11 , and in accordance with embodiments described below. 
         [0070]    Referring to  FIG. 12 , the locking spindle  1200  includes a body portion  1205  having a proximal end  1201  and a distal end  1203 . The distal end  1203  includes a retaining ring  1210 . The body portion  1205  includes an opening  1250  for receiving the inflow port  320 , the outflow port  330 , and the microwave transmission cable assembly  102  ( FIG. 13 ). The body portion  1205  further includes a pair of longitudinal slots  1220 . As shown in  FIG. 12 , the longitudinal slots  1220  separate a first circular end  1222  from a second circular end  1224 . The pair of longitudinal slots  1220  and their respective first and second circular ends  1222 ,  1224  are configured to receive the pins  1010 ,  1020  ( FIG. 10 ) as will described in further detail below. The distal end  1203  may further define an aperture  1215  for receiving the cannula  314  ( FIG. 13 ) into which the feed line  106  and radiating section  106   a  have been inserted. The longitudinal slots  1220  may also be referred to as camming surfaces. The first and second circular ends  1222 ,  1224  may be of equal size. 
         [0071]    The body portion  1205  also includes an opening or cut-out  1230 . The opening  1230  extends a length of the body portion  1205  such that the inflow port  320 , the outflow port  330 , and the distal end  103  of the microwave transmission cable assembly  102  are accommodated therein ( FIG. 16B ). The opening  1230  may be offset from the pair of longitudinal slots  1220 . The offset may be a 90-degree offset. 
         [0072]    Referring to  FIG. 13 , the assembled view  1300  illustrates the sliding spindle  600  assembled over the multi-lumen hub  300  received in the locking spindle  1200  such that the pins  1010 ,  1020  of the sliding spindle  600  engage their respective longitudinal slots  1220  of the locking spindle  1200 . The pins  1010 ,  1020  slide along their respective longitudinal slots  1220  such that the pins  1010 ,  1020  travel from or between the first circular end  1222  and the second circular end  1224 . A biasing means, such as a spring (not shown) forces the pins  1010 ,  1020 , away from the body portion  610  of the sliding spindle  600  and into engagement with the circular end  1222 , as shown in  FIG. 13 . 
         [0073]    Referring to  FIG. 14A , an actuator, such as a control ring  1400 A is shown and includes a body portion  1410  having a proximal end  1401  and a distal end  1403 . The proximal end  1401  has a pair of projections  1430  extending outward from the body portion  1410 . The pair of projections  1430  defines a first arm section  1432  and a second arm section  1434 . The first arm section  1432  is substantially perpendicular to the body portion  1410  or the longitudinal axis “Z” defined through the body portion  1410 . The second arm portion  1434  is, for example, a curved portion. The pair of projections  1430  forms a handle member for manual manipulation. The body portion  1410  also defines an opening or cut-out  1420  for receiving or accommodating therein the inflow port  320 , the outflow port  330 , and the microwave transmission cable assembly  102  ( FIG. 17 ). The control ring  1400 A further defines a channel or through passage  1450  therethrough. The interior surface of the control ring  1400 A may include one or more stops  1460 . 
         [0074]    Referring to  FIG. 14B , the control ring  1400 B includes a body portion  1410 ′ having a proximal end  1401 ′ and a distal end  1403 ′. The proximal end  1401 ′ has a first pair of projections  1430 ′ extending outward from the body portion  1410 ′ and a second pair of projections  1440 ′ extending outward from the body portion  1410 ′. The first and second pair of projections  1430 ′,  1440 ′ may be substantially perpendicular to the body portion  1410 ′ or the longitudinal axis “Z” defined through the body portion  1410 ′. The first and second pair of projections  1430 ′,  1440 ′ may form a handle member for manual manipulation. The body portion  1410 ′ also defines an opening or cut-out  1420 ′ for receiving or accommodating therein the inflow port  320 , the outflow port  330 , and the microwave transmission cable assembly  102  ( FIG. 17 ). The control ring  1400 B further defines a channel  1450 ′ therethrough. The interior surface of the control ring  1400 B may include one or more stops  1460 ′. 
         [0075]    Both the sliding spindle  600  and the control arm  1400 A are described herein as an actuator. One of skill in the art will recognize that in accordance with the present disclosure these two actuators may operate individually or in concert, and they may act on different components of the assemblies described herein. 
         [0076]    The deployment of the cannula  314  housing the coaxial feed line  106  and radiating section  106   a  will now be described with reference to  FIGS. 15A and 15B .  FIG. 15A  is a cross-sectional view  1500 A of the control ring  1400 A of  FIG. 14A  assembled onto the locking spindle  1200  of  FIG. 12  and sliding spindle  600  of  FIG. 11 , where the cannula  314  is in a deployed position, in accordance with aspects of the present disclosure. 
         [0077]      FIG. 15A , the control ring  1400 A is assembled onto or mounted on the locking spindle  1200  such that the pins  1010 ,  1020  of the sliding spindle  600  travel along the slotted openings  1220  of locking spindle  1200 . The opening  1420  ( FIG. 14A ) may extend a substantial length of the body portion  1410  of the control ring  1400 A. In the deployed position, the sliding spindle  600  rests in the lower portion of the area  1550  defined by the locking spindle  1200 , and the pins  1010 ,  1020  rest within the second circular ends  1224  proximate the distal end  1403  of the control ring  1400 A. The second sections  1013 ,  1023  ( FIG. 10 ) of the pins  1010 ,  1020 , respectively, are protruding members such that when the pins are depressed into the recesses  630  of the sliding spindle  600 , they permit the movement of the sliding spindle  600  relative to the locking spindle  1200  via slotted opening  1220  and prevent the removal of the sliding spindle  600  from the locking spindle  1200 . 
         [0078]      FIG. 15B  is a cross-sectional view  1500 B of the control ring  1400 A of  FIG. 14A  assembled onto the locking spindle  1200  of  FIG. 12  and sliding spindle  600  of  FIG. 11 , where the cannula  314  is in a retracted position, in accordance with aspects of the present disclosure. 
         [0079]    In the retracted position, the sliding spindle  600  rests in the upper portion of the area  1550  defined by the locking spindle  1200 . In both these configurations, the transition head  110  remains secured to the multi-lumen hub  300  within the sliding spindle  600 , and the cannula  314  moves relative to the locking spindle  1200 . In the retracted position, the pins  1010 ,  1020  rest within the first circular ends  1222  or at the proximal end  1401  of the control ring  1400 A. 
         [0080]    Additionally, since the control ring  1400 A is mounted onto the locking spindle  1200 , the control ring  1400 A also moves relative to the sliding spindle  600 . Thus, when a holding force “A” is applied to the sliding spindle, and an actuating force “C” is applied to the pair of projections  1430 , of the control ring  1400 A such that the sliding spindle  600  does not move, the control ring  1400 A moves in a direction “B.” This movement results in the change depicted by comparison of  FIG. 15B , retracted position, to  FIG. 15A , deployed position. In such a transition, the pins  1010 ,  1020  travel along their respective longitudinal slots  1220  between the first circular ends  1222  and the second circular ends  1224 . The sliding spindle  600  engages the inner surface  1525  of the locking spindle  1200  within the area  1550 . Thus, the locking spindle  1200  selectively locks the sliding spindle  600  between an extended position and a retracted position. As a result, the cannula  314  may be extended and retracted based on relative movement of the sliding spindle  600  and the control ring  1400 A and the locking spindle  1200 . 
         [0081]      FIG. 16A  shows an alternate view of the control ring  1400 A of  FIG. 14A  assembled onto the locking spindle  1200  of  FIG. 12 , where the cannula  314  and sliding spindle  600  are in the retracted position. Similarly,  FIG. 16B  shows an alternate view of the control ring  1400 A of  FIG. 14A  assembled onto the locking spindle  1200  of  FIG. 12 , where cannula  314  is placed in the deployed position.  FIGS. 16A and 16B  show the inflow port  320 , the outflow port  330 , and the microwave transmission cable assembly  102  extending through the opening  1230  ( FIG. 12 ) of the locking spindle  1200  and the opening  1420  ( FIG. 14A ) of the control ring  1400 A. In addition, the inflow port  320 , the outflow port  330 , and the distal end  103  of the microwave transmission cable assembly  102  move within the area defined by the opening  1230  of the locking spindle  1200  and the opening  1420  of the control ring  1400 A (when transitioning between extended and retracted positions). 
         [0082]    As noted above with reference to  FIGS. 16A and 16B , the inflow port  320 , the outflow port  330 , and the distal end  103  of the microwave transmission cable assembly  102  move within the area defined by the opening  1230  ( FIG. 12 ) of the locking spindle  1200  and the opening  1420  of the control ring  1400 A (when transitioning between extended and retracted positions). The openings  1230  and  1420  overlap each other.  FIG. 17  also provides an alternate perspective view of the sliding spindle  600 , within the locking spindle  1200 , and the control ring  1400 A. 
         [0083]      FIG. 18  depicts a nose cone  1800  for connection to locking spindle  1200 . The nose cone  1800  includes a body portion  1810  defining an upper body section  1811  and a lower body section  1813 . The upper body section  1811  includes a cut-out section  1815 . The body portion  1810  has a distal portion  1820  formed at the lower body section  1813 . The distal portion  1820  has an aperture  1830 . 
         [0084]    Referring to  FIG. 19 , the upper body portion  1811  is configured to receive the distal end  1203  of the locking spindle  1200  ( FIG. 12 ) and the distal end  1403  ( FIG. 17 ) of the control ring  1400 A. The cut-out section  1815  of the upper body portion  1811  is configured to surround the outflow port  330 . The cannula  314  extends through the aperture  1830  of the distal portion  1820  of the nose cone  1800 . Thus, the aperture  1830  is adapted and dimensioned to receive the cannula  314 . 
         [0085]    As shown in  FIG. 20 , the nose cone  1800  includes a recess  2010  on an inner surface  2012  thereof for receiving a retaining ring  1210  of the locking spindle  1200 . The recess  2010  is an annular recess defined along the inner surface  2012  of the nose cone  1800 . The retaining ring  1210  interacts with the recess  2010  to secure the nose cone  1800  to the locking spindle  1200 . 
         [0086]    In  FIG. 21 , the locking mechanism  2110  is shown positioned on a distal end  2114  of a flat surface  2112  of the distal portion  1820  of the nose cone  1800 . The locking mechanism  2110  is configured to mate with a trocar/cannula assembly described below with reference to  FIGS. 23A-23D . 
         [0087]      FIG. 22  depicts a fully assembled microwave ablation assembly  2200  including a housing  2212  covering spring-biased coupling element  104  for connection to a microwave generator. The microwave transmission cable assembly  102  may include covering having a slot  2214  through which a first fluid flow channel  2216  and a second fluid flow channel  2218  exit. The first fluid flow channel  2216  is connected to the inflow port  320  and the second fluid flow channel is connected to the outflow port  330 . Though not shown, the microwave generator may include a fluid source and enable connection of the fluid source through the housing  2212 . 
         [0088]    Insertion and deployment of the microwave ablation assembly  2200  is described with reference to  FIGS. 23A-24 .  FIG. 23A  depicts a rigid cannula  2310  including a housing  2316  connected to a shaft  2312  having a distal portion  2314 . The housing  2316  includes a slot  2318  for receiving a locking mechanism  2328  or  2110 .  FIG. 23B  shows the trocar  2320 , which includes a retaining member  2326  connected to a shaft portion  2322  having a distal tip  2324 . The retaining member  2326  includes a locking mechanism  2328 . Referring now to  FIGS. 23C and 23D , the locking mechanism  2328  of the trocar  2320  mates with the slot  2318  of the housing  2316  of the cannula  2310 . The locking mechanism  2328  secures the trocar  2320  to the cannula  2310 . The trocar  2320  is thus releasably coupled to the cannula  2310 . The distal tip  2324  may be a relatively pointed tip to pierce through tissue. 
         [0089]    Typically a clinician, when performing for example a liver ablation procedure, will acquire a series of images to identify the location of a tumor or lesion for ablation. Once identified, the clinician will seek to place the cannula  2310  and trocar  2320  assembly as shown in  FIG. 23D  proximate that tumor or lesion. This placement may be performed through a variety of techniques including under fluoroscopy, ultrasound, MRI, and CT imaging techniques either alone or in combination with one or more navigation techniques, such as electromagnetic navigation. Once the cannula  2310  and trocar  2320  assembly is positioned in a desired location within a patient proximate the tumor or lesion, the trocar  2320  may be removed. The cannula  2310  remains in place ready to receive the microwave ablation assembly  2200  or where appropriate the performance of one or more pre-treatment biopsies. 
         [0090]    The microwave ablation assembly  2200  may then be placed within the cannula  2310  at the desired location proximate the tumor or lesion and secured to the cannula  2310  via locking mechanism  2110  on the nose cone  1800  and slot  2310  on the housing  2316  of the cannula  2310 . However, to protect the feed line  106  and radiating section  106   a , within the cannula  314 , the cannula  314  is not yet deployed from the cannula  2310 . To deploy the cannula  314 , within which is housed the feed line  106  and, more specifically, the radiating section  106   a , the control ring  1400 A and locking spindle  1200  must be compressed relative to the sliding spindle  600 . By the relative movement of the locking spindle over the sliding spindle  600  (which is preferably held stationary), the cannula  2310  is retracted relative to the cannula  314 , exposing the cannula  314 , and specifically, the radiating section  106   a  housed therein. 
         [0091]      FIG. 24  shows the cannula  314  extended beyond the distal end of the cannula  2310 . In this position, the cannula  2310  has been retracted, thus exposing cannula  314  and the radiating section  106   a  of the microwave ablation assembly  2200 . The cannula  314  has been exposed by application of pressure on the control ring  1400 a ( FIG. 14A ) which overcomes the retaining force imparted by the pins  1020 ,  1030  ( FIG. 10 ), thus allowing control ring  1400 a and locking spindle  1200  ( FIG. 12 ) to move relative to the sliding spindle  600  ( FIG. 6 ). In this position, the microwave assembly  2210  is in a position to perform an ablation. 
         [0092]    As described herein, in a preferred embodiment of the present disclosure, the sliding spindle  600 , the multi-lumen housing  300 , and the microwave transmission and radiation component  100  remain fixed in space (or remain stationary) when the cannula  314 , and more particularly the radiating section  106   a  is deployed to a surgical site or target. The locking spindle  1200 , the control ring  1400 A, and the nose cone  1800  are drawn in a direction away from the surgical site when the radiating section  106   a  is deployed to the surgical site or target. 
         [0093]    The present disclosure enables placement of a cannula  314 , which may be flexible, including radiating section  106   a , from a non-radiofrequency transparent access lumen such as cannula  2310  in a variety of interventional procedure types. These interventional procedures include transcutaneous placement (analogous to rigid biopsy kit), open procedure (rigid-needle-like), laparoscopic procedure (hand assisted placement). By use of the cannula  2310  and trocar  2320 , an access path to a particular treatment site can be considered separately from the energy delivery device constraints. It is further envisioned that the methods and devices described herein can enable vascular access, whereby a cannula  314 , being of flexible construction could be placed with steerable guide-wires. Still further, hybrid procedures utilizing a cannula  314  that is partially rigid and partially flexible are also contemplated. 
         [0094]    In accordance with another aspect of the present disclosure, access approaches are envisioned where following placement of the cannula  2310  and removal of the trocar  2320 , the cannula  314 , which may include steerable guide wires or may be inserted through a flexible guide sheath with steerable guide-wire can extend the access path with 4-dimensional freedom. 
         [0095]    The systems and methods of the present disclosure enable an improved workflow by separating the clinician&#39;s needs during the access channel placement from the clinician&#39;s needs associated with energy delivery. By utilizing the cannula  2310  and trocar  2320  separately, from the microwave ablation assembly  2200 , the clinician does not have to deal with constraints of the microwave ablation assembly  2200  while placing the cannula  2310 . This removal of the concerns of microwave cables, fluid lines, device weight, handle length, etc., greatly improves the clinician&#39;s ability to focus on cannula  2310  placement at or near the target site, and further allows for easier imaging of the placement site (e.g., by fluoroscopy or CT imaging). Still further, because the microwave and fluid componentry is not employed during the cannula  2310  insertion steps, through space savings within the device, the trocar  2320  and cannula  2310  may ‘onboard’ additional capabilities such as EM navigation sensors, temperature sensors, device fixation features, and other diagnostic capabilities. 
         [0096]    In accordance with the present disclosure, the cannula  2310  may have a smaller diameter gauge or French size) than existing devices for placement of microwave ablation components. Indeed, the cannula  2310  may be one of a series of cannulas which are used to dilate the size of the opening in order to receive the microwave ablation assembly  2200 . 
         [0097]    Detailed embodiments of devices, systems incorporating such devices, and methods using the same as described herein. However, these detailed embodiments are merely examples of the disclosure, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for allowing one skilled in the art to variously employ the present disclosure in appropriately detailed structure. 
         [0098]    While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Any combination of the above embodiments is also envisioned and is within the scope of the appended claims. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope of the claims appended hereto.
A microwave ablation system includes a first cannula, a trocar insertable through the first cannula and configured to facilitate insertion of the first cannula into a target tissue, and a microwave antenna assembly configured to interlock with the first cannula, the microwave antenna assembly including a coaxial feedline having a radiating section formed thereon, the microwave antenna configured to be inserted into the first cannula. The microwave ablation system further includes an actuator operatively connected to one of the first cannula or microwave antenna assembly. Operation of the actuator between a first position and a second position exposes the radiating section of the microwave antenna assembly from a distal portion of the first cannula.