Patent Description:
The availability of safe and effective therapy for tricuspid valve (TV) disease remains an area of significant unmet clinical need. Tricuspid regurgitation (TR) or the pathologic leakage of blood back into the right atrium during systole, quite common in cardiac patients with left-sided valvular or myocardial disease, is estimated to affect ><NUM> million people in the United States, with a yearly incidence of about <NUM>,<NUM> and ><NUM>,<NUM> patients in the United States and Europe, respectively. Specific anatomic features from the TV complex might vary according to the causing mechanism (primary vs. secondary) and throughout the progressive stages of ventricular remodeling in patients with functional TR. TR is most often functional, primarily due to annular dilatation and leaflet tethering from right ventricular remodeling caused by left-sided heart disease, atrial fibrillation, or pulmonary hypertension. Primary TR accounts for ~<NUM>% of cases of TR and can be due to congenital (Ebstein's anomaly, prolapse) or acquired diseases (rheumatic, endocarditis, carcinoid, endomyocardial fibrosis, intracardiac leads, or bioptome-related iatrogenic trauma). Today, TV disease is often considered a marker for late-stage chronic heart failure. TV is associated with a grim prognosis with most patients receiving lifetime medical therapy until intractable right heart failure and end-organ dysfunction appear.

Secondary TR has been divided into three stages for therapeutic purposes. In the early stage, initial dilation of the right ventricle leads to tricuspid annular dilation without significant leaflet tethering. Annular-based systems should easily repair TR in these first stages. In the absence of long-term durability data for transcatheter TV therapy and on the basis of a surgical predicate, ring may be preferred over suture annuloplasty when possible in order to reduce TR recurrence. In the second stage, progressive right ventricular and tricuspid annular dilation develop, impairing leaflet coaptation. The likelihood for successful Transcatheter Tricuspid Valve Repair (TTVr) using annuloplasty alone is less suitable in cases with progressive tethering and tricuspid annular dilation. Finally, as the right ventricle continues to remodel, further leaflet tethering worsens, resulting in a lack of coaptation and massive or torrential TR. When severe tethering occurs, any repair attempt could be considered futile.

<FIG> is a side cross-sectional view of a heart. The heart <NUM> is shown schematically with some of the relevant anatomical features in view. The tricuspid valve <NUM> (TV) is a complex structure, with several anatomic peculiarities rendering it unique. The TV apparatus, shown in <FIG>, normally has three leaflets, the septal leaflet <NUM>, the posterior leaflet <NUM>, and the anterior leaflet <NUM>, chordae tendineae <NUM>, and usually three papillary muscles <NUM>. Also shown are the general locations of a superior vena cava <NUM> and an inferior vena cava <NUM>.

As shown in <FIG>, the tricuspid annulus valve <NUM> is the largest of four heart valves, with very thin, fragile leaflets composing a potentially large regurgitant orifice area. The tricuspid valve <NUM> is surrounded by the tricuspid valve annulus <NUM> a saddle-shaped ellipsoid that becomes planar and circular as it dilates primarily in the anterolateral free wall in patients with left-sided heart disease with sinus rhythm verses expanding mostly along the posterior border with less prominent leaflet tethering in patients with functional TR secondary to chronic atrial fibrillation. The three leaflets, an anterior leaflet <NUM>, septal leaflet <NUM>, and posterior leaflet <NUM> are also shown in <FIG>. The relative locations of a mitral valve <NUM> and mitral annulus <NUM>, as well as a aortic valve <NUM> and aortic annulus <NUM>, and a pulmonary valve <NUM> and pulmonary annulus <NUM> are also indicated for reference. Four chief anatomic structures surround the TV and are therefore at risk for interventions addressing TV disease: the conduction system (atrioventricular node and the right bundle of His) coursing the membranous septum at <NUM> to <NUM> from the anteroseptal commissure, the right coronary artery (encircling the right atrioventricular groove ~<NUM> from the septal and posterior portions, <NUM> from the anterior portion), the non-coronary sinus of Valsalva, and the coronary sinus ostium being an important landmark of the posteroseptal commissure. The TV apparatus poses additional challenging issues to overcome: lack of calcium, angulation in relation to the superior vena cava (SVC) and inferior vena cava (IVC), a trabeculated and thin right ventricle hindering a transapical approach, or the presence of pre-existing cardiac implantable electronic devices.

Traditional isolated TV surgery typically requires highly invasive surgical access and cardio-pulmonary by-pass. Since this current approach continues to be associated with one of the highest risks of mortality among all cardiac valve procedures in contemporary practice (operative mortality rates of <NUM>% to <NUM>%), it is rarely utilized relative to the large number of untreated TR patients (only <NUM>,<NUM> isolated tricuspid procedures were performed in a large contemporary U. nationwide registry over a <NUM>- year period). Durability remains the Achilles heel of most surgical interventions addressing the TV. Many factors, such as right ventricular remodeling and dysfunction, tricuspid annular size progression, and pulmonary hypertension, may contribute to the high rates of TR recurrence observed following surgical TR correction. Surgical experience has shown more sustained durability of ring annuloplasty compared with suture annuloplasty, as well as for TV replacement over repair. However, concerns about increased perioperative mortality for TV replacement compared with repair in contemporary series-somewhat linked to selection bias of patients with larger tricuspid annular dilation and more severe right ventricular dysfunction-have led to a trend over time toward TV repair rather than replacement.

Modern advances in cardiac surgery have made it possible to repair or replace heart valves using minimally invasive surgical techniques. As minimally invasive techniques have improved, surgeons have been able to operate on patients through smaller and smaller access holes, resulting in less perioperative pain and shorter recovery times. While more steps continue to be taken to reduce the amount of time a patient must be on cardio-pulmonary bypass (CPB), surgeons continue to push the boundaries of what is possible by striving to be able to perform certain surgeries on a beating heart without the need for CPB. It would be even more desirable to be able to perform specific cardiac surgical procedures on a beating heart under minimally invasive conditions. For example, it would be highly desirable to be able to perform a tricuspid valve repair through a cannula placed between a patient's ribs and into the right atrium of the heart while the heart is still beating. The pressure in the right atrium is such that the blood would tend to fill partially into such a cannula, and of course, there would be blood within the right atrium which would also, unfortunately, completely obscure a surgeon's view of the right atrium and the tissues of the tricuspid valve if such an approach were to be taken. Even echocardiography, on its own, would have a difficult time allowing the surgeon to orient a suturing device through the blood field for a series of related stitches. Therefore, it would be desirable to have a minimally invasive suture placement system and method which would provide access to and enable reliable suture placement around a cardiac valve, such as a tricuspid valve, even under conditions of zero direct and zero endoscopic visibility to enable minimally invasive beating heart surgery for better patient outcomes. Faster and more reliable cardiac operations offer additional benefits, such as reduced surgical team fatigue and more efficient use of critical resources. Expediting cardiac surgery can also improve patient outcomes. Minimally invasive surgical access systems could find utility in other areas of surgery or surgicalprocedures.

Different types of surgical access system as such are known from the prior art. Hereto, <CIT> discloses a surgical access system comprising a cannula and an obturator. The cannula comprises a distal member including suction ports. <CIT> discloses an apparatus for sealing a gastric opening including a delivery device. The delivery device comprises an anchorable cannula comprising foldable arms. In between two groups of foldable arms a circumferential ring is comprised, which is configured to guide tissue such as a gastric wall. <CIT> discloses a surgical access assembly comprising a longitudinal passageway that is configured to receive a surgical instrumentation for guiding the surgical instrumentation. The longitudinal passageway comprises also a distal tip having a plane surface.

<CIT> discloses a device system comprising a tubular access device having an inner lumen provided for positioning through a penetration in a muscular wall of the heart. The access device having a means for sealing within the penetration to inhibit leakage of blood through the penetration and an obturator that is removably positionable in the inner lumen of the access device, the obturator having a cutting means at its distal end for penetrating the muscular wall of the heart. <CIT> discloses surgical access cannulas and access systems for use in gaining access to a body cavity of a patient via a natural orifice.

The invention is set out by the appended claims, which define a surgical access system having sagittal, frontal, and transverse planes. The surgical access system having a cannula includes a distal tip configured to enable secure attachment of suture or suture tubes to the cannula having one or more longitudinal channels distributed around a circumference of the distal tip, wherein the one or more longitudinal channels are configured to releasably hold sutures or suture tubes, one or more circumferential channels including a cinch suture channel around the distal tip, wherein the one or more circumferential channels are configured to provide an indentation to guide a suture or tissue within that circumferential channel, and one or more bridges defining a bridge orifice distributed circumferentially along the cinch suture channel. The surgical access system also includes an obturator coaxially insertable within the cannula which may include a distal tip and a retractable cutting element having an actuator.

The surgical access system also includes an articulation interface configured to provide re-positionable and independent movement in the sagittal, frontal, and transverse planes of the surgical access system. The obturator further may include an elongated tube. The obturator further may include a slidable plunger element configured to control fluid flow inside the elongated tube of the obturator.

A method (not forming part of the invention) of accessing a surgical site is also disclosed. The method of accessing a surgical site also includes placing at least one pursestring suture in a wall of a heart, securing the at least one pursestring suture to a cannula, placing an obturator tip of a surgical access system having a retractable blade in contact with the wall of a heart, incising the wall with the retractable blade, and securing the incised wall to the cannula of a surgical access system.

<FIG> is a top-right perspective view of a cannula for use in a surgical access system. The cannula <NUM> has a proximal end 50P which is oriented closest to a surgeon and a distal end 50D oriented away from a surgeon during use. The cannula <NUM> has a cannula top <NUM> at the proximal end 50P coupled to a cannula top coupler <NUM> and then coupled to a cannula tube <NUM>. The cannula tube is a hollow elongated tube in this illustrated embodiment. A cannula distal tip <NUM> is coupled to the distal end 50D of the cannula tube <NUM>. The cannula <NUM> has a universal ball joint <NUM> slidably engaged onto the cannula tube <NUM> of the cannula <NUM>. The universal ball joint <NUM> defines an opening <NUM> and a set screw channel <NUM>. The opening <NUM> is located opposite a hinge (not shown in this view). The universal ball joint <NUM> is configured such that the universal ball joint <NUM> may be slidable along the length of the cannula tube <NUM> and be set at the discretion of the surgeon based on anatomical variations between patients based on the distance between a chest wall and a right atrium of a patient's heart, for example, or for other anatomical distances inherent to a particular surgical site to which one might wish to gain access. Once a desired location for the universal ball joint <NUM> is determined, a set screw <NUM> is inserted along axis <NUM> and tightened to restrict the universal ball joint <NUM> from moving during a minimally invasive surgical procedure. While a set screw channel <NUM> is shown in this embodiment, and a tension adjusting set screw <NUM> is described in regard to this embodiment, other means of setting, adjusting, or readjusting the tension of the universal ball joint <NUM> or other similar slidable joint may be obvious to one skilled in the art. This universal ball joint <NUM> may be separate from or continuous with the cannula <NUM>. The universal ball joint <NUM> or alternate embodiments thereof may be referred to as an articulation interface. An articulation interface for the surgical access system described herein is an interface coupled to or connected to the surgical access system that allows for and is configured to provide re-positionable and independent movement in three planes. In an anatomical context these three planes of movement may be referred to as sagittal, frontal, and transverse, while in a Cartesian coordinate system the three planes may be referred to as x, y, and z. It should be understood that these referential planes of movement are provided for context and are intended to cover alternate reference planes or descriptions of planes of movement.

<FIG> is an exploded view of the assembly steps for the cannula of <FIG>. The cannula distal tip <NUM> further defines a circumferential pursestring suture channel <NUM>, several longitudinal grooves <NUM> or longitudinal channels, a cinch suture channel <NUM>, several bridges <NUM>, the bridges <NUM> further defining a bridge orifice <NUM> (not shown in this view), and a cannula tip opening <NUM>. The cinch suture channel <NUM> and the pursestring suture channel <NUM> are circumferential channels located on the cannula tip <NUM> and configured to provide an indentation to guide a suture or tissue or other material within that circumferential channel. It should be understood that the term "suture," as used herein, is intended to cover any thread, cable, wire, filament, strand, line, yarn, gut, or similar structure, whether natural and/or synthetic, in monofilament, composite filament, or multifilament form (whether braided, woven, twisted, or otherwise held together), as well as equivalents, substitutions, combinations, and pluralities thereof for such materials and structures.

Additional functions of the various channels and other features of the cannula distal tip <NUM> will be further described later in regard to <FIG>. The cannula tip <NUM> is placed onto and fixedly attached to the distal end 54D of the cannula tube <NUM> along axis <NUM>. The universal ball joint <NUM> defines the set screw channel <NUM> and opening <NUM>, and further defines a flexible hinge <NUM> and a center channel <NUM>. The flexible hinge is configured to allow the universal ball joint <NUM> to open slightly and allow the universal ball joint <NUM> to be slidable along the length of the cannula tube <NUM> when not under tension from a set screw, for example. The universal ball joint <NUM> is next placed on the proximal end 54P of the cannula tube <NUM> along axis <NUM>. The universal ball joint <NUM> may be located at any point along the cannula tube <NUM> depending on any anatomical variations in distance related to the external position of a patient relative to the internal surgical site being accessed. Finally, the cannula top <NUM>, which defines a cannula top coupler <NUM> is fixedly coupled over a cannula tube spacer <NUM> along axis <NUM>, and the cannula top <NUM> is fixedly attached to the proximal end 54P of the cannula tube <NUM>. This step holds the universal ball joint <NUM> captive along the length of the cannula tube <NUM>. The components assembled in <FIG> are fixedly attached via brazing, welding, ultrasonic welding or by other means of joining known to those skilled in the art. Furthermore, individual components described in relation to the assembly of the cannula may be formed in combination and may not necessarily be separate components.

<FIG> is perspective view of an obturator for use in a surgical access system. The obturator <NUM> has a proximal end 92P which is oriented closest to a surgeon and a distal end 92D oriented away from a surgeon during use. The obturator <NUM> has an obturator distal tip <NUM> coupled to an obturator tube <NUM> at the distal tip 92D of the obturator <NUM>. The specific details and features of this obturator distal tip <NUM> will be discussed later in regard to <FIG>. The proximal end 92P of the obturator <NUM> has an obturator knob <NUM>, a plunger knob <NUM>, and a cutter knob <NUM>. These knobs <NUM>, <NUM>, <NUM> can be actuated by the operator to utilize the features of the obturator <NUM> portion of the surgical access system described herein. The obturator knob <NUM> further defines a stopcock <NUM>, which further defines a vacuum inlet <NUM> and a valve <NUM>. The vacuum inlet can be connected to a source for delivering vacuum or other fluid flow to or from the obturator distal tip <NUM>. The magnitude of flow can be controlled, turned on, or turned off by actuating the valve <NUM>. The assembly and specific features and details of the components of the obturator <NUM> will be discussed in regard to <FIG>. Alternate means of fluid flow or airflow regulation known to one skilled in the arts may also be used.

<FIG> are a series of exploded views of assembly steps for the obturator portion of the surgical access system of <FIG>. <FIG> illustrates an assembly step of the obturator <NUM>, showing a cutter blade <NUM> having a cutter blade edge <NUM> and two holes <NUM> being inserted along axis <NUM> into a slot <NUM> defined by a cutting element drive rod <NUM>. The cutting element drive rod <NUM> also defines two holes <NUM> on either side of the slot <NUM>. <FIG> illustrates the insertion of two pins <NUM> through the two holes <NUM> on the cutting element drive rod <NUM>, through blade holes <NUM> on the cutter blade <NUM>, and finally through two corresponding holes (not shown in this view) on the opposite side of the cutter drive rod <NUM>. These pins <NUM> hold the blade on the end of the cutting element drive rod <NUM>. Other embodiments may include a single piece cutting element or similar configurations obvious to those skilled in the art. <FIG> illustrates the completed subassembly of a cutting element <NUM>. This retractable element <NUM> can be actuated independently from other mechanisms within the obturator <NUM>, for example the slidable plunger element, which will be discussed later. While this element <NUM> is constructed with a mechanical blade as its functional cutting element, other sharpened tools capable of piercing or forming controlled incisions may be useful alternate embodiments of cutting elements, for example, a scalpel, scissors, cauterizing elements, laser elements, and the like. While the cutter blade <NUM> in this embodiment has a cutter blade edge <NUM> on the patient-facing or distal side of a rectangular-shaped cutter blade <NUM>, a scalpel may have a triangular-shaped cutter blade having either one side or both sides with a sharpened edge. The retractable cutting element may also be in the form of scissors, wherein two blade members have opposing sharpened edges that slide against each other when actuated or pivoted against one another in contact with tissue to initiate a cutting motion.

<FIG> illustrates another assembly step for the obturator portion of the surgical access system of <FIG>. A vacuum plunger <NUM> defines a plunger recess <NUM> having a smaller diameter than the vacuum plunger <NUM>. The vacuum plunger <NUM> further defines two vacuum ports <NUM> and a blade slot <NUM> that communicate throughout the entire length of the vacuum plunger <NUM>. The two vacuum ports <NUM> are configured to deliver fluid flow from the vacuum inlet <NUM> of the obturator <NUM> to the obturator distal tip <NUM> when the vacuum plunger <NUM> is pulled back towards a proximal direction, and cut off the fluid flow from the vacuum inlet <NUM> of the obturator <NUM> to the obturator distal tip <NUM> when the vacuum plunger <NUM> is pushed forward into a more distal direction. The vacuum plunger <NUM> is further configured to fit tightly within the obturator tube <NUM> and may have gaskets or other means of sealing or blocking fluid flow between the vacuum plunger <NUM> and the obturator tube <NUM>. Other embodiments of a vacuum plunger <NUM> may have different numbers or orientations or shapes of vacuum ports as compared to those illustrated herein. Further, alternate methods of controlling vacuum to the obturator distal tip <NUM> may be employed and would be known to those skilled in the art. The blade slot <NUM> is configured to allow the cutter blade edge <NUM> of the cutting element <NUM> to pass through the length of the vacuum plunger <NUM> when the cutting element <NUM> is inserted into the blade slot <NUM> of the vacuum plunger <NUM> along axis <NUM>. The subassembly of <FIG> is completed by placing a plunger drive tube <NUM> over the cutting element <NUM> along axis <NUM> and fixedly attaching the plunger drive tube <NUM> to the vacuum plunger <NUM>. The cutting element <NUM> is configured to slide back and forth within the plunger drive tube <NUM>. The plunger drive tube <NUM> or hollow actuator is a slidable plunger element that can be independently actuated from the actuation of the element <NUM>. <FIG> illustrates the result of the assembly step for the obturator shown in <FIG>. The internal obturator assembly <NUM> is shown in this view.

<FIG> illustrates another assembly step for the obturator portion of the surgical access system of <FIG>. The obturator distal tip <NUM> defines a cutting element slot <NUM>, a stop ring <NUM>, several tip ports <NUM>, and a shaft connection recess <NUM>. The cutting element slot <NUM> is configured to align with the blade slot <NUM> in the vacuum plunger <NUM>, as described previously, and allow the cutting element <NUM> to extend through the obturator distal tip <NUM> when in use. The tip ports <NUM> are passages for fluid flow to pass therethrough, configured on either side of the element slot <NUM> such that they do not align with the two vacuum ports <NUM> on the vacuum plunger <NUM> when the vacuum plunger <NUM> is pushed distally. This embodiment illustrates tip ports <NUM> in two groups of passages, each distinct group located on either side of the blade slot <NUM>. The blade slot <NUM> may be considered a central passage. In general, these passages are in communication or in contact from the tip of the instrument to the opposite end or port where fluid may be introduced when the fluid flow is turned on or actuated. Conversely, when the fluid flow is turned off, there is an interruption of flow between the tip of the instrument to the opposite end or port where fluid may be introduced. This can be achieved by having hollow cylindrical members throughout, specific ports in various internal components, solid tubes or cylinders with lumens or internal channels, or any combination thereof. There may be alternate embodiments having more than two groups of passages in arrangements known to those skilled in the art. This arrangement effectively cuts off the fluid flow when the vacuum plunger <NUM> is pushed distally against the inside of the obturator distal tip <NUM>. The obturator tube <NUM> is a hollow elongated tube or cylinder defining a center <NUM>. Alternate embodiments may not be hollow, but rather solid tubes, and may therefore have lumens or channels along the length of the tube for actuation of various cutting elements, plunger elements, or fluid flow components. The shaft connection recess <NUM> on the obturator distal tip <NUM> is configured to be inserted along axis <NUM> until the stop ring <NUM> contacts the end of the obturator tube <NUM>. The obturator distal tip <NUM> is then fixedly attached to the obturator tube <NUM>, completing this assembly step. <FIG> illustrates the result of the assembly step for the obturator shown in <FIG>. The external obturator assembly <NUM> is shown in this view. <FIG> illustrates another assembly step for the obturator portion of the surgical access system of <FIG>. The internal obturator assembly <NUM> of <FIG> is inserted into the external obturator assembly <NUM> of <FIG> along axis <NUM>. <FIG> illustrates the result of the assembly step for the obturator shown in <FIG>. An obturator subassembly <NUM> is shown in this view, showing the orientation and placement of the obturator distal tip <NUM>, obturator tube <NUM>, plunger drive tube <NUM>, and the cutting element drive rod <NUM>.

<FIG> illustrates another assembly step for the obturator portion of the surgical access system of <FIG>. The obturator subassembly <NUM> of <FIG> is shown. Obturator knob <NUM> further defines a central hole <NUM> and a vacuum port <NUM> configured to communicate fluid flow from the stopcock <NUM> (not shown here) through to the obturator distal tip <NUM>. The obturator knob <NUM> is fixedly attached to the obturator tube <NUM> by sliding the obturator knob <NUM> over the cutting element drive rod <NUM> and the plunger drive tube <NUM> and onto the end of the obturator tube <NUM>. Plunger knob <NUM> defines a central hole <NUM> and is fixedly attached to the plunger drive tube <NUM> by inserting the plunger drive tube <NUM> into the central hole <NUM> of the plunger knob <NUM> along axis <NUM>. It should be noted that the plunger drive tube <NUM> and the attached plunger knob <NUM> move independently from the previously installed obturator knob <NUM> as well as independently from the cutting element drive rod <NUM>. The cutter knob <NUM> also defines a central hole. Finally, the cutting element drive rod <NUM> is inserted into the central hole <NUM> on the cutter knob <NUM> along axis <NUM> and fixedly attached thereto. In this embodiment, the obturator knob <NUM> does not move once assembled in the obturator. The plunger knob <NUM> moves the plunger drive tube <NUM> and therefore the vacuum plunger <NUM> distally and proximally independent from the obturator knob <NUM> and the cutter knob <NUM>. This plunger knob may also be considered an actuator or a plunger actuator as this feature is used to actuate or influence the movement of the vacuum plunger <NUM> and therefore actuate the fluid flow through the obturator <NUM> on or off as appropriate. Also, the cutter knob <NUM> moves the cutting element drive rod <NUM> and hence the cutter blade <NUM> distally and proximally independent from the obturator knob <NUM> and the plunger knob <NUM>. This cutter knob <NUM> may also be considered an actuator or a cutting actuator as this feature is used to actuate or influence the movement of the cutting element <NUM>. The cutting element drive rod <NUM> may also be considered an actuator rod, or an actuation drive rod as this rod or wire is used to actuate or move the cutter blade <NUM> in and out of the cutting element slot <NUM> in the obturator distal tip <NUM>. <FIG> illustrates the result of the assembly step for the obturator shown in <FIG>, showing the assembled orientation and positions of the obturator distal tip <NUM>, obturator tube <NUM>, obturator knob <NUM>, plunger knob <NUM>, and cutter knob <NUM>.

<FIG> illustrates the final assembly step for the obturator portion of the surgical access system of <FIG>. The vacuum port <NUM> defined by the obturator knob <NUM> is a fluid passage configured to accept the stopcock <NUM> by inserting the central hole <NUM> defined by the stopcock <NUM> into the vacuum port <NUM> along axis <NUM>. The vacuum port <NUM> is a passage that allows for fluid flow from outside of the surgical access system to the inside of the obturator tube <NUM> of the obturator <NUM>. This assembly step results in the obturator <NUM> of <FIG>.

<FIG> is a side view of the obturator portion of the surgical access system of <FIG>. The side view shows the assembled obturator <NUM> with additional details regarding the articulation of the plunger knob <NUM> and the cutter knob <NUM>. Arrow <NUM> indicates the direction of articulation of the plunger knob <NUM>. When plunger knob <NUM> is moved toward the distal end 92D of the obturator <NUM>, the plunger drive tube <NUM> coupled to plunger knob <NUM> also moves distally and independently from the inserted cutter drive rod <NUM>, and the fluid flow through the obturator <NUM> is cut off, as previously described. Conversely, when the plunger knob <NUM> is moved toward the proximal end 92P of the obturator <NUM>, plunger knob <NUM> also moves proximally along with the coupled vacuum plunger <NUM>, and the fluid flow through the obturator <NUM> is turned on. Arrow <NUM> indicates the direction of articulation of the cutter knob <NUM>. When cutter knob <NUM> is moved toward the distal end 92D of the obturator <NUM>, cutter drive rod <NUM> also moves distally, independently within the plunger drive tube <NUM>, and cutter blade <NUM> is actuated or advanced out of the obturator tip <NUM>, as previously described. Conversely, when cutter knob <NUM> is moved toward the proximal end 92P of the obturator <NUM>, cutter drive rod <NUM> also moves proximally, independently within the plunger drive tube <NUM>, and cutter blade <NUM> is retracted into the obturator tip <NUM>.

<FIG> is an exploded view illustrating an assembly step for a surgical access system. <FIG> shows an optional surgical instrument holder <NUM> terminating with a clamp adapter <NUM> attached to its end. The clamping adapter <NUM>, shown open, is placed over the universal ball joint <NUM> of the cannula <NUM> of <FIG>, the jaws <NUM> are closed and tightened by tightening the adjustment screw <NUM>. The obturator <NUM> of <FIG> is inserted into the center of the cannula <NUM> along axis <NUM>. <FIG> is a perspective view of the surgical access system of <FIG>.

A surgical access system <NUM> is illustrated which can be used to provide access to a patient's right atrium for the purpose of performing a minimally invasive tricuspid valve repair as previously described. Similar embodiments of the surgical access system <NUM> may also be useful in other procedures where minimally invasive access to a surgical site is advantageous. The surgical access system has the cannula <NUM>, the obturator <NUM>, and the universal ball joint <NUM>. The universal ball joint is held in a clamp adapter <NUM> having an adjustment screw <NUM> and a lever lock <NUM>. The clamp adapter <NUM> is attached to a surgical instrument holder <NUM> which holds the surgical access system <NUM> in a potential initial position for use in a minimally invasive surgical procedure. The clamp adapter <NUM> has jaws <NUM> which hold the universal ball joint <NUM> that is slidably attached to the cannula tube, as previously described. Alternate embodiments of a clamping adapter or alternate clamping elements would be known to those skilled in the art. The universal ball joint <NUM> in combination with the clamp adapter <NUM> and the surgical instrument holder <NUM> provide multiple degrees of freedom of movement and the ability to position the surgical access system in any number of positions advantageous for targeted access to a minimally invasive surgical site. Suitable surgical equipment holders, such as, but not limited to, the miniARM™ INSTRUMENT HOLDER from LSI Solutions, Inc. (Victor, NY, www. lsisolutions. com) are intended for use in such surgical procedures.

An advantageous feature of the articulation interface in the embodiments described herein is that the universal ball joint <NUM> can first be set along the length of the cannula tube <NUM> depending on anatomical variations as appropriate. This provides articulation along the axis of the cannula tube <NUM>, providing articulation in one plane. Having a substantially spherical universal ball joint <NUM> held within a clamping element or clamp adapter <NUM> as shown provides adjustment in the remaining two dimensions. This arrangement of the universal ball joint <NUM> and the clamp adapter <NUM> provides articulation in all planes and is thus repositionable by a surgeon to flexibly provide access to a minimally invasive surgical site. With the clamp adapter <NUM> attached to a surgical instrument holder <NUM> as shown in <FIG> and <FIG>, even further adjustability and repositionability may be attained by the operator or surgeon. Alternatively, a universal joint may be used in a surgical access system such as the one described herein. A universal joint is a coupling or joint that connects more than one segment, tube, rod or limb on a general apparatus. The segment axes are inclined to each other and may or may not transmit rotary motion. The coupling includes a pair of hinges in proximity to one another, connected by a cross-shaped shaft. A universal joint configured in such an arrangement allows for rotational motion of the rods or segments while the rods or segments coupled by the joint are not oriented in a straight line.

<FIG> are several side-views of surgical steps illustrating one use of the surgical access system of <FIG>. <FIG> illustrates the wall of the right atrium or the right atrial wall <NUM>, which is the target surgical site for a surgical access system such as the one described herein. In preparation for use of the surgical access system, the location of the universal ball joint <NUM> along the length of the cannula tube <NUM> is set. An appropriate right anterior access site is selected, and an incision is made within the 2nd intercostal space, at the right lateral border of the chest wall. The subcutaneous tissue and along with major muscle fibers and intercostal muscle fibers are split and divided, using blunt dissection whenever possible. A suitable access port is installed, optionally with the use of a retractor. Also optional is the use of an appropriate suture management apparatus. Further dissection, movement, or removal of fat or other tissue is performed as needed. During the subsequent steps of the surgical procedure outlined herein, additional visualization methods may be used to aid placement of the surgical access system <NUM>.

<FIG> is a side-view of a surgical step illustrating the use of the surgical access system of <FIG>. <FIG> illustrates two concentric pursestring sutures <NUM>, <NUM> about the right atrial wall <NUM> incision site so that one end of each pursestring suture enters and exits the right atrial wall <NUM>. This can be accomplished using a suitable surgical suturing device such as, but not limited to, the PRESTIGE™ device from LSI Solutions, Inc. (Victor, NY, www. lsisolutions. Once the pursestring sutures <NUM>, <NUM> are completed, they are both snared, using a device such as, but not limited to, a MINI-RUMEL® device from LSI Solutions, Inc. (Victor, NY, www. lsisolutions. com) for each of the pursestring sutures <NUM>, <NUM>. <FIG> illustrates both pursestring sutures <NUM>, <NUM> snared and encapsulated within their respective suture tubes <NUM>, <NUM>. Such a device is one method of employing a suture snare, but other means of snaring, organizing and encapsulating sutures during a minimally invasive surgical procedure may be well known to those skilled in the art. Examples include, a simple snare in tube arrangement where the suture or snare may be held in position with common clamping methods such as butterfly clamps and the like, or where a suture locking apparatus may be used to lock and unlock the position of a suture within a tube releasably and repeatedly. The suture tubes <NUM>, <NUM> are attached to the longitudinal grooves <NUM> located on the distal tip <NUM> of the cannula <NUM>. The longitudinal grooves <NUM> or channels are configured to releasably hold sutures or suture tubes such that they are held close to the cannula during use. Prior to subsequent surgical steps illustrated herein, the suture tubes <NUM>, <NUM> are further secured to the distal tip <NUM> of the cannula <NUM> using a cinch suture <NUM> along the cinch suture channel <NUM> of the cannula tip <NUM> as shown in <FIG>.

<FIG> is a side-view of a surgical step illustrating the use of the surgical access system of <FIG>. The surgical step illustrates the next steps in an exemplary surgical sequence utilizing the surgical access system <NUM> described herein. <FIG> shows the distal end 174D of the surgical access system <NUM> introduced into the surgical site and moved into position with the obturator distal tip <NUM> in direct contact with the right atrial wall <NUM>. The universal ball joint <NUM> has been translated to the appropriate position on the cannula tube <NUM> to account for the distance from the chest wall of the patient and the right atrial wall <NUM>. The cinch suture <NUM> is shown threaded over the suture tubes <NUM>, <NUM>, through the cinch suture channel <NUM> and into one or more bridge orifice <NUM> located under one or more bridges <NUM> located on the cannula tip <NUM>. The cinch suture <NUM> further secures the suture tubes <NUM>, <NUM> around the circumference of the cannula <NUM> of the surgical access system <NUM>. The suture tubes <NUM>, <NUM> are also held into their respective longitudinal grooves <NUM> with the cinch suture <NUM> providing added security. It should be noted that pursestring suture <NUM>, <NUM> movement is not restricted within the suture tubes <NUM>, <NUM> when secured by the cinch suture <NUM>. The cinch suture <NUM> may be fastened using a knot or mechanical fastener, but is not shown in this view. The suction feature of the obturator tip <NUM> should be activated as described previously, by opening the stopcock valve on the obturator knob, and actuating the plunger knob and therefore the plunger drive tube and the vacuum plunger. The activation of the vacuum flow brings the tissue of the right atrial wall <NUM> under additional tension against the obturator distal tip <NUM> by applying suction through the obturator distal tip <NUM> via the tip ports <NUM> which are grouped on either side of the blade slot <NUM>. The blade slot <NUM> is an elongated passage through which a blade element or cutting element can pass through, and is separate from the passages in the obturator distal tip <NUM> that permit fluid flow through the obturator distal tip <NUM>.

<FIG> is a side-view of a surgical step illustrating the use of the surgical access system of <FIG>. <FIG> shows the actuation of the retractable blade of the surgical access system <NUM>. While the obturator distal tip <NUM> is in close contact with the right atrial wall <NUM>, the cutter knob <NUM> is actuated by the user at the proximal end of the obturator <NUM> by pushing the cutter knob <NUM> in direction <NUM>, towards the right atrial wall <NUM>. Actuating the cutter knob <NUM> in turn pushes the cutting element drive rod <NUM> and likewise the cutter blade edge <NUM> of the cutter blade <NUM> in direction <NUM>, incising the tissue of the right atrial wall <NUM>. This leaves an incision <NUM> in the right atrial wall <NUM> tissue.

<FIG> is a side-view of a surgical step illustrating the use of the surgical access system of <FIG>. After the incision <NUM> is made in the right atrial wall <NUM>, the cutter blade <NUM> is quickly retracted and the cannula tip <NUM> is advanced into the incised right atrial wall <NUM> at the site of the incision <NUM>. The cannula tip <NUM> is advanced until the right atrial wall <NUM> is placed within the circumferential pursestring suture channel <NUM> of the cannula tip <NUM> at the point of incision <NUM>. The pursestring sutures <NUM>, <NUM> are snugged using suture locks or other apparatus such as MINI-RUMEL®. Appropriate positioning of the cannula <NUM> location is can again be confirmed by adjustment of the universal ball joint <NUM> within the clamp adapter <NUM> and by repositioning the surgical instrument holder <NUM>. Suction is also turned off and discontinued at this point. The obturator <NUM> portion of the surgical access system <NUM> is removed from the incision <NUM> and from the minimally invasive surgical site, leaving the cannula <NUM> in place for any additional surgical procedures to be performed.

<FIG> are front, left side, right side, rear, top, and bottom elevational views, respectively, of the distal tip of the cannula of <FIG>. These views illustrate in greater detail and from various points of view the features of the cannula tip <NUM> including the circumferential pursestring suture channel <NUM>, the longitudinal grooves <NUM>, the cinch suture channel <NUM>, the cannula tip opening <NUM>, and several bridges <NUM>. As shown previously, each bridge <NUM> defines a bridge orifice <NUM>, which accommodates the cinch suture. The cinch suture can go over or under the bridge <NUM> and may not necessarily be threaded through the bridge orifice <NUM>. Alternate embodiments of cannula tips may have a differently configured or angled tip and may have differing numbers of grooves or of orifices for retaining suture, thread, wire or tissue.

<FIG> are front-views of an alternate embodiment of an obturator for a surgical access system illustrating a rotating ramp feature. <FIG> shows a front view of a distal tip of the obturator in a retracted position. An obturator distal tip <NUM> as previously described defining several tip ports <NUM> and a cutting element slot <NUM> also defines a ramp recess <NUM> located on the outer circumference of the obturator distal tip <NUM>. The ramp recess <NUM> is sized and configured to accommodate the rotational movement of a rotation ramp <NUM>, which is shown here as a partial circular shaped element. The rotation ramp defines an external profile having a base surface <NUM> and a ramp surface <NUM>, and a side profile surface <NUM>. The base surface <NUM> is substantially circular as observed from the front-end view as shown in <FIG>, while the ramp surface <NUM> extends circumferentially beyond the substantially circular profile defined by the base surface <NUM> when rotated. The side profile surface <NUM> defines an arc that follows the outer circumferential profile of the obturator distal tip <NUM> when the rotation ramp <NUM> is in the retracted position. The rotation ramp <NUM> rotates about a pivot point <NUM>. This rotation is controlled by an actuator <NUM>, which in this embodiment is depicted as a lever, placed at a location proximal to the obturator distal tip <NUM>, such as near the obturator knob <NUM> described previously, for example.

<FIG> shows a front view of a distal tip of the obturator in an extended position. The actuator <NUM> has been moved in a direction <NUM> that in turn has rotated the rotation ramp <NUM> about the pivot point <NUM> such that the side profile surface <NUM> has been moved into the ramp recess <NUM> and the ramp surface <NUM> is now located on the outer circumference of the obturator distal tip <NUM> which increases the effective circumference of the obturator distal tip <NUM> temporarily while the rotation ramp <NUM> is in the extended position. It should be noted that shapes other than the one shown may be utilized in a rotation ramp <NUM> for the purpose of temporarily increasing the effective circumference of the obturator distal tip <NUM>. In the event that additional circumference or girth is required to assist in advancing the cannula and obturator of the surgical access system into the incised atrial wall, the rotation ramp <NUM> has a shape that when rotated provides a temporary increase in the effective circumference of the obturator tip <NUM>. The rotation ramp <NUM> can be actuated, extended, or retracted by an actuator <NUM> such as the illustrated lever, or alternatively a button, a knob, or other means known to those skilled in the art. The actuator may alternatively be in other places on the obturator. The rotation ramp <NUM> is further configured within the obturator distal tip <NUM> in such a fashion that when the obturator is fully inserted into the cannula in the described surgical access system, the rotation ramp <NUM> extends beyond the cannula tip such that the rotation ramp <NUM> can be extended past the circumference defined by the surgical access system. In an actuated or extended position as shown in <FIG>, the rotation ramp <NUM> expands or pulls tissue in an outward direction such that it assists in getting tissue over the cannula tip and into cannula tip circumferential pursestring suture channel.

Claim 1:
A surgical access system (<NUM>) having sagittal, frontal, and transverse planes and comprising:
a cannula (<NUM>) comprising:
a distal tip (<NUM>) configured to enable secure attachment of sutures (<NUM>, <NUM>) or suture tubes (<NUM>, <NUM>) to the cannula (<NUM>);
an obturator (<NUM>); and
an articulation interface (<NUM>);
wherein the distal tip (<NUM>) of the cannula (<NUM>) comprises:
one or more longitudinal channels (<NUM>) distributed around a circumference of the distal tip (<NUM>), wherein the one or more longitudinal channels (<NUM>) are configured to releasably hold sutures (<NUM>, <NUM>) or suture tubes (<NUM>, <NUM>);
one or more circumferential channels (<NUM>, <NUM>) including a cinch suture channel (<NUM>) around the distal tip (<NUM>), wherein the one or more circumferential channels (<NUM>) are configured to provide an indentation to guide a suture (<NUM>) or tissue (<NUM>) within that circumferential channel (<NUM>); and
one or more bridges (<NUM>) defining a bridge orifice (<NUM>) distributed circumferentially along the cinch suture channel (<NUM>);
wherein the obturator (<NUM>) is coaxially insertable within the cannula (<NUM>) and comprises:
a distal tip (<NUM>; <NUM>); and
a retractable cutting element (<NUM>) having an actuator (<NUM>).