Low-profile surgical universal access port

A surgical access device includes an elongate cannula having a side wall at the proximal end that is coaxial with and movable relative to a seal-housing. A seal assembly that includes at least one seal is disposed within the seal-housing. An inflation port is formed in on the seal housing and configured to align with an opening in the side wall at the proximal end of the cannula. The seal housing is movable relative to the side wall between an open and closed configuration. In an open configuration, the inflation port is aligned with the opening in the side wall permitting fluid to flow across the cannula side wall. In a closed configuration, the inflation fort is offset from the opening in the side wall preventing fluid flow across the cannula side wall. In one variation, a resilient retention member is disposed inside the seal housing to bias the seal.

FIELD

This invention relates to surgical access devices, and more particularly, to trocars for use in laparoscopic, minimally invasive surgery.

BACKGROUND

One type of surgical access device is commonly referred to as a trocar. Typically, the term “trocar” is used to describe a combination of a cannula, a cannula seal housing, and an obturator. The obturator is a penetrating instrument typically associated with the cannula and inserted through the seal housing and into the lumen of the cannula to expose a penetrating tip of the obturator at the distal end. The cannula seal housing operates to maintain pneumoperitoneum pressure while instruments are inserting into the lumen of the cannula and into the abdominal cavity. The terms “access port” and “access device” are also used to refer to a trocar.

Advances in laparoscopic or minimally invasive surgery have placed new demands on access devices. Because of the increasing complexity of surgical procedures now performed laparoscopically, as well as developments in the instrumentation used in such procedures, improvements, upgrades, and/or redesigns of presently available access devices are desirable. For example, in the early years of laparoscopy, laparoscopic cholecystectomy was considered a complex procedure, which typically included placing three to five access ports and using about three different instruments. Now, laparoscopic cholecystectomy is considered routine surgery and even performed using a single incision in the patient's umbilicus. Other laparoscopic procedures include more complex surgery of the intestine, stomach, lung, uterus, spleen, liver, etc. Instruments specifically developed for such procedures are often complex and asymmetrical, and may include, for example, undercuts, side openings, and sharp regions that can damage and/or destroy a trocar seal. Procedures in which a wide range of instrument sizes are inserted through an access port produce additional issues. For instance, in some procedures instrument diameters range from about 4.5 mm to over about 15 mm. In such procedures, maintaining pneumoperitoneum pressure as small instruments are moved within a region of the seal system designed to accommodate larger instruments is challenging. Also, complex instrumentation requires more space for manipulation and a greater range of motion inside and outside the patient.

Furthermore, access ports placed in a patient may have a tendency to flop around when no instrument is inserted and consequently, when a surgeon attempts to insert an instrument into the access port, the opening of the access port is not in the appropriate position, thereby, necessitating realignment or repositioning of the access point. Other areas for improvement include constructs that secure the seal and prevent it from tearing or overlapping when instruments are inserted and removed. The present invention provides a new and improved trocar that meets these needs.

SUMMARY

The present invention provides a surgical access device. The surgical access device includes an elongate tubular cannula having a lumen extending between a proximal end and a distal end. The cannula has a side wall that extends radially outwardly relative to the distal end of the cannula forming an enlarged lumen at the proximal end. The cannula includes an opening extending through the side wall at the proximal end. A seal housing is connected to and coaxial with the proximal end of the cannula and configured to be sealingly movable relative to the side wall. An inflation port extends through the seal housing and is configured to align with the opening in the side wall to fluidly connect the inflation port and opening with the cannula lumen. A seal assembly includes at least one seal disposed in the seal housing. The seal housing is movable relative to the side wall between an open configuration and a closed configuration. In the open configuration, the inflation port is in alignment with the opening in the side wall, thereby, fluidly connecting the inflation port and opening with the cannula lumen. In the closed configuration, the lumen of the inflation port is offset from the opening in side wall, thereby, fluidly isolating the inflation port from the opening in the side wall.

According to another aspect of the invention, a surgical access device is provided. The surgical access device includes an elongate tubular cannula having a lumen extending between a proximal end and a distal end. A seal housing is connected to the proximal end of the cannula. A seal assembly is disposed inside the seal housing and includes at least one seal. An access channel is defined along a longitudinal axis extending through the seal assembly and lumen of the cannula from the proximal end to the distal end. The device further includes a resilient member having a proximal end and a distal end. The resilient member is located between the seal assembly and the seal housing.

According to another aspect of the invention a method is provided. The method includes the step of moving a seal housing relative to a cannula. The seal housing is generally cylindrical and movably connected to the cannula. The cannula has a generally cylindrical side wall defining a central lumen along a longitudinal axis that is coaxial with the lumen of the seal housing. The seal housing is sealingly connected to the side wall at the proximal end of the cannula such that the seal housing can move relative to the side wall of the cannula. A seal assembly includes at least one seal and is disposed inside the seal housing at the proximal end. The seal housing includes an inflation port and the side wall of the cannula includes an opening configured such that alignment of the inflation port and opening places the cannula lumen and a plenum distal of the seal assembly into fluidic communication with outside of the cannula via the opening and outside of the seal housing via the inflation port. The seal housing is movable relative to the cannula between an open position and a closed position. In the open position, the opening and inflation port are at least on partial alignment. In the closed position, the opening and the inflation port are misaligned preventing fluidic communication across the seal housing. The method further includes the step of bringing into at least partial alignment the inflation port of the seal housing and the opening of the side wall of the cannula. Fluid is moved under pressure through the lumen of the cannula after the at least partial alignment of the inflation port of the seal housing with the opening in the side wall of the cannula. The inflation port and the opening in the side wall of the cannula are completely misaligned to shut fluidic communication across the side wall through the opening and across the seal housing through the inflation port.

According to another aspect of the invention, a surgical access device is provided. The surgical access device includes an elongate tubular cannula having a lumen extending between a proximal end and a distal end. A seal housing is connected to the proximal end of the cannula. The seal housing includes an access channel coaxial with the lumen of the cannula. The seal housing includes an outer side wall having a first opening movable relative to an inner side wall having a second opening. At least one seal is disposed inside the seal housing. The first and second openings are configured to align at least in part to fluidly connect the cannula lumen across the seal housing and configured to move completely out of alignment. The outer side wall is movable relative to the inner side wall between an open configuration and a closed configuration. In the open configuration, the first opening is in alignment at least in part with the second opening, thereby, fluidly connecting the cannula lumen across the seal housing. In the closed configuration, the first opening is offset from the second opening, thereby, closing fluidic communication across the seal housing.

DETAILED DESCRIPTION

With particular reference toFIGS. 1-3,FIG. 1is a side view of a patient10placed upon a surgical table5in a supine position in preparation for a minimally invasive surgical procedure on the patient's abdomen20. InFIG. 2, the abdomen20of the subject10is inflated with an insufflation gas, which distends the abdominal wall15, thereby creating an unobstructed working area25within the abdomen20, as illustrated in partial cross section inFIG. 3. Examples of suitable abdominal procedures include operations on the appendix, spleen, liver, kidneys, stomach, gall-bladder, intestinal tract, and the like. As illustrated inFIGS. 2 and 3, multiple access ports40are placed through the patient's abdominal wall15in some procedures and laparoscopic instrumentation100is inserted into the working lumen42of the access ports40. Specialized instrumentation100has been developed that fit through the small working lumen42and also accommodate patients10with very thick abdominal walls15and/or vast abdominal cavities20.

Compatibility with the full range of existing laparoscopic instrumentation is often compromised because of a length of the access device40. For example, as illustrated inFIG. 3, a long and/or tall seal housing41relative to a shorter, low-profile access port150limits the operational range of some instruments100inserted therein. Furthermore, access devices40that are long and/or tall, and extend out from the external abdominal wall15tend to flop over and/or fail to remain in preferred positions. Furthermore, a misaligned access port40is typically positioned and/or stabilized by an additional hand, either the surgeon's or an assistant's, before guiding the instrument100into the working lumen42of the device40.

FIG. 4is a side view of an access port40placed through a body wall15with an instrument100accessing a body cavity20therethrough. An operative, distal portion45of the instrument extends into the body cavity20to an intended site therein to perform a surgical procedure. In some cases, a thick body wall15and/or a vastly extended body cavity20prevents or reduces the reach and/or unencumbered use of some instruments100. Moving the access port40towards the body wall15such that the distal end of the seal housing41abuts the entry point16in the abdominal wall as illustrated inFIG. 5compromises the mobility of the access port40. Consequently, an instrument100inserted into the working lumen42of such an access port40in the condition illustrated inFIG. 5may not have the desired range of motion.FIGS. 6 and 8are side views of an instrument100inserted in a typical access port40with a tall seal housing41.FIGS. 7 and 9are side views of a variation of an access port150with a shorter, low-profile, seal housing with an instrument100inserted therein. As shown in these drawings, the low-profile access port150illustrated inFIGS. 7 and 9provides an increased functional range for the instrument100as shown by the greater exposure and hence mobility of the distal end44as well as at the proximal end of the instrument100compared with the typical access port40illustrated inFIGS. 6 and 8.

Referring to bothFIGS. 6 and 7, the distal end47of the cannula portion46is approximately at the same depth inside the patient in each of theFIGS. 6 and 7, with the cannula portions46being approximately the same length. At the proximal end48, the cannula extends the same height from the point of entry16. However, due to the lower profile of the access port150there is more room for the instrument100to be manipulated at the proximal end while maintaining the same mobility at the distal end as can be seen inFIG. 7when compared with the access port with the tall seal housing41depicted inFIG. 6where the instrument mobility is curtailed. InFIG. 7, the instrument100can be moved further distally; whereas, the instrument inFIG. 6cannot be moved distally without also moving access device further distally and thereby affecting the distal mobility because the instrument100abuts the proximal end of the seal housing41. This limited mobility affects the types of instruments that can be employed, in particular, instruments that have a complex articulating distal end44as shown or that require more space to be manipulated at the proximal end.

Referring to bothFIGS. 8 and 9, the low profile seal housing150and the tall seal housing are both shown to abut the entry point16. The low profile seal housing150permits the instrument100more mobility to move to a greater depth inside the patient when compared with the tall seal housing41ofFIG. 8. Of course, more of the distal end44of the instrument is advantageously exposed from beyond the cannula portion46.

Referring now toFIGS. 10-20, various views of an access device150with a low profile seal housing according to the present invention are provided. The access device150comprises a longitudinal axis extending from a proximal end to a distal end thereof. A seal housing200is disposed at the proximal end. A cannula151extends distally from the seal housing200. An instrument access channel extends from the proximal end to the distal end of the access device150, which is substantially coincident and coaxial with the longitudinal axis in the illustrated variation. The cannula151and the seal-housing200are sized and configured such that the access device150has a low profile and/or short height. Some variations of the access device150also exhibit at least one of light weight and simplified construction.

With particular reference toFIG. 13, which is a side cross section of the access device150, the cannula151comprises an elongate portion158, sized and configured to penetrate through tissue such as a body wall and is adapted to mate with an obturator (not shown) that is inserted through the lumen153to extend out from the distal end152. The elongate portion158has an inner diameter dimensioned to accommodate a range of instrumentation for which the access port150is designed. The cannula151comprises a distal end152, a proximal end157, and a lumen153extending therebetween and through which the instrument access channel extends. In the illustrated variation, the distal end152is tapered and/or beveled, which facilitates placement of the access device150through a body wall. The proximal end157of the cannula151flares out in a portion in which the cross-sectional area of the lumen153is relatively larger than the distal portion of the cannula151. The proximal end157also engages a distal end of the seal housing200at a ledge formed in the base154of the cannula proximal portion. The lumen153extends from the distal end152of the cannula to a base154at the proximal end157thereof. The lumen153is fluidly connected to an open plenum274in the seal housing200.

In some variations of the surgical access device150, the cannula151is releasably coupled to the seal housing200. In other variations, the cannula151is not releasably coupled to the seal housing200. For example, in some variations, the cannula151is not designed for release from the seal housing200after they are coupled together. Some variations comprise a plurality of cannula151in a range of sizes, each of which is dimensioned to couple to a common seal housing200. For example, some variations comprise a plurality of cannula151, each of which accommodates a different range of instrument diameters, for example, up to about 5 mm, up to about 8 mm, up to about 11 mm, up to about 12 mm, or up to about 15 mm. Some variations comprise cannula151of different working lengths, for example, with working lengths of about 55 mm, about 75 mm, about 100 mm, or about 150 mm, for example. Interchangeability permits the cannula portion151to be sterilized and re-used.

Still referencingFIGS. 10-20, the seal housing200in the illustrated variation comprises a generally cylindrical body201comprising a distal end282, a proximal end298, and a midsection284. The distal end282engages the proximal portion157of the cannula. As shown inFIG. 20, the mid-section284of the seal housing200comprises a cylindrical wall284slidingly and rotatably disposed around a coaxial proximal cylindrical side wall136of the cannula151. As best seen inFIGS. 13 and 17, a distal end282of the cylindrical wall284of the seal housing200contacts a ridge or shelf278. The cylindrical wall284of the seal housing200sealingly contacts the proximal cylindrical wall136of the cannula, thereby substantially preventing gas flow therebetween, as will be apparent from the description below.

With particular reference toFIGS. 17-20, a proximal, seal-housing-engaging portion177of the cannula151is an enlarged portion of the cannula151having a larger cross-sectional area. This enlarged portion177is integrally formed with the cannula151or may be connectable thereto. The proximal, seal-housing engaging portion177is cylindrical and configured to engage with the seal housing200in a coaxial manner with the seal housing200encompassing the enlarged portion177of the cannula151. The seal housing200slides over the enlarged portion177engages the seal-housing200, providing a substantially gas-tight arrangement. An O-ring276disposed between the seal-housing-engaging portion177of the cannula151and the seal-housing200provides the substantially gas-tight seal, as well as a detent retention feature. The distal end282of the seal housing200is disposed within recess or slot278of the cannula151and is configured to connect thereto such that relative rotation of the two elements is permitted. For example, the recess or slot278is formed with an undercut (not shown) to snap fit with a lip (not shown) formed on the seal housing200. In the illustrated variation, the O-ring is captured in a groove141disposed on a proximal cylindrical wall136of the cannula. The O-ring276also permits the cannula151to be manually separated from the seal-housing200. The cylindrical wall284of the seal housing200is arranged concentrically around the proximal cylindrical wall136of the cannula151inside a gap142between the cylindrical wall136and projections155,156. Projections155,156extend radially outwardly from the cannula base154and extend proximally.

As best seen inFIGS. 19 and 20, which are an exploded side and perspective views, respectively, of the access device150, a plurality of seal members300and320are received within the cylindrical wall284of the seal housing200and captured or trapped therein by a cap or end member270closing the top of cylindrical wall284of the seal-housing200. As illustrated inFIGS. 17,18and20, the seal housing200comprises the ridge or shelf279extending inwardly from a wall284thereof. Some variations of the ridge or shelf279comprise a tractive surface and/or features that contact and secure the seal members300and320.

In the illustrated variation, a first seal member320a generally frustoconical elastomeric member with an opening322sized and configured to conform to and seal around the shaft of an instrument inserted therethrough, which is also referred to as an instrument seal. A second seal member300comprises an elastomeric check-valve or duck-bill valve sized and configured to seal the lumen153and plenum274of the access port150when no instrument is within the working channel or lumen153, which is also referred to as a zero seal. Each seal member320and300further comprises a radially extending portion321,301, respectively, sized and configured to allow the seal members300and320to float and/or pendulate, for example, responsive to and following the movement of an inserted instrument within the working channel153of the access port150. The radially extending portions321,301of one or more of the first seal member320and second seal member300are captured between the cap270and shelf279and depending portions310,311of seals300,320pendulate therefrom. Other variations comprise a different configuration of seals, for example, a single seal that serves as both an instrument seal and a zero seal. An example of such a seal is a gel seal.

As best seen inFIGS. 13,19and21, in the illustrated variation, the cap or end member270comprises a generally flat member that is sized and configured to snap into and/or engage the proximal portion of the seal-housing200in a connecting fashion and to secure or hold the associated seal members300and320in place within the access port150. The cap or end member270comprises a seal-housing engaging portion272, a distal-facing surface230, a proximal-facing surface231, and a generally cylindrical projection232defining a central bore271. The central bore271comprises a through-hole sized and configured to allow passage of surgical instruments therethrough. For example, some variations of the central bore271accommodate instruments of from about 3.5 millimeters to about 16 millimeters in diameter. Therefore, the central bore271in the cap270is at least about 16 millimeters, for example.

A connecting hub or fitting203sized and configured for coupling to a gas supply is disposed on the mid-section284of the seal housing. In the illustrated variation, the hub203extends radially outwardly from the seal housing200. In other variations, the hub203has another configuration, for example, extending longitudinally, tangentially, or in another direction. In the variation illustrated inFIG. 10, the connecting hub203comprises a standard, male connecting portion205, for example, a Luer fitting, and a through-lumen204. The through-lumen204reduces restriction of gas flow therethrough with the device in an open configuration, as discussed below.

As best seen inFIG. 18, the distal end282of the seal-housing200comprises a projection281that corresponds with and fits inside a recess or slot278in the base154of the cannula. In the assembled access port150, the projection281fits into the recess278, which has an angular width greater than an angular width of the projection281, thereby, conferring the seal housing200with a degree of rotation relative to the cannula151around the longitudinal axis. The seal-housing200is rotatable between a first position and a second position. In a first or open position, the through lumen204of an inflation port203disposed on the midsection284of the seal-housing aligns with a side opening or hole206in a side wall136at the proximal portion297of the cannula, thereby fluidly connecting the inflation port203with the plenum274. Rotating the seal housing200to the second or closed position offsets lumen204of the inflation port from the side opening206, thereby fluidly isolating the inflation port203from the plenum274. Consequently, an angle of rotation of the seal housing200between the first position and the second position is greater than the larger of the angle subtended by lumen204of the inflation port and the side opening206in the side wall of the cannula. The inflation port203on the seal housing200and the side opening206in the side wall136of the cannula together define a fluid valve, which is integrated with the seal housing200and cannula151creating a access port having a low profile. The illustrated arrangement of an aligned and non-aligned lumen204and opening206eliminates bulky and complex valves, stopcocks, and the like and permits a shorter seal housing and greater range of motion and mobility of the access port as well as reducing manufacturing costs.

As illustrated inFIGS. 14-17, the connecting hub203is integrally manufactured with the seal housing200of the access port150rather than a separate part assembled therewith. In some variations, the cannula151and the seal housing200comprise rigid plastic, thereby facilitating integrally molding or forming the connecting hub203in the manufacture of the seal-housing200. In some variations comprising a metal seal-housing200, the connecting hub203is separately manufactured and subsequently secured or coupled to the seal-housing200. In some variations, the connection hub203is adjustable, for example, pivotable and/or rotatable relative to the seal housing200.

Those skilled in the art will understand that other variations comprise other arrangements. For example, in some variations, the projection281is disposed on the cannula151and the recess or slot278on the seal housing200. Other variations comprise a pair of stops such as projections155,156that together with the projection281limit the rotation of the seal housing200. In the variation illustrated inFIG. 18, the projection281extends longitudinally. In some variations, the projection281extends radially inward and/or outward. Similarly, in some variations, the side wall136is a component of cannula151rather than the seal housing200.

In the illustrated variation, as best seen inFIG. 16, the access device150comprises a first elongate projection155and a second elongate projection156, each of which is connected to the base154and extends axially upwardly from the base154of the cannula151toward the proximal end thereof forming a gap142between the grip element155,156and the cylindrical wall136of the cannula. Into this gap142, the seal housing200is inserted and configured to closely conform and rotate about the cylindrical wall136. As best seen inFIG. 15, which is a top view of the access device150, inwardly facing surfaces143and144of the projections156and155, respectively, are radially spaced from the cylindrical wall284of the assembled seal housing200, thereby permitting the seal-housing200to rotate freely around the longitudinal axis of the cannula151. The projections155and156are sized and configured to provide the cannula151with a traction feature, as discussed below. Applying a compressive or force tangential to the cylindrical wall284of the seal housing200between one of the projections155and156, and the inflation hub203, for example, by grasping between a user's thumb and index finger, or otherwise squeezing/pressing one of the projections155,156and inflation hub203together rotates the seal housing200relative to the cannula151, thereby converting the access device150between the open and closed configurations described above, in which the opening206and the lumen204of the inflation port are aligned and offset, respectively. The opening206in the side wall136of the cannula151of the access port150is adjusted to align with the lumen204of the inflation port203of the seal-housing200, and/or the seal-housing200is adjusted to align the lumen204of the inflation port203with the side opening206of the cannula151in converting the access device150to the open configuration. The aligned lumen204and opening206fluidly connect a gas supply coupled to the inflation port203with the main lumen153of the cannula151for movement of fluid across the cannula such as for insufflation of a body cavity. In one variation, the second projection is not connected to the cannula but is formed by the outwardly extending inflation port and is coincident with the seal housing. In another variation, the angle subtended by the first and second projections is less than 90 degrees defining their maximum degree of separation. Also, in another variation, the invention is not limited to relative rotation of the seal housing and cannula to effect alignment of the inflation port and opening. For example, the seal housing can slide up and down relative to the cannula to align the inflation port of the seal housing with the opening in the cannula between an open position in which fluid is permitted to flow across the cannula and seal housing into the lumen and a closed position in which fluid is prevented from flowing across the cannula and seal housing and into the lumen. Of course, partial alignment of the opening with the inflation port can be effected to regulate the rate of fluid flow.

The variation illustrated inFIG. 15comprises indicia163and164indicating the state of the integral valve and/or guiding the user in converting the valve between the open and closed states. For example, in some variations, the indicia are color-coded or the like, thereby indicating the current state of the valve, its alignment or rate of flow.

Turning now toFIGS. 21-23, there is shown another variation of the low profile access port150that illustrates a first projection155connected to base154of the proximal end of the cannula157that projects radially outwardly and extends proximally and is spaced apart from the cylindrical wall136of the cannula151to form a gap142. As described above, the seal housing200slides over the cylindrical wall136of the cannula in a coaxial manner to rest inside the gap142between the cylindrical wall136first projection155and into a snap-fit engagement with the cannula contacting a ridge or shelf with a seal such as an O-ring as described above with the previous variations. A second projection400is formed on the seal housing200. The second projection400extends radially outwardly from the outer surface284of the seal housing. As shown by indicia401inFIG. 21, the opening206in the side wall is in alignment with the connecting hub lumen203resulting in a first open position in which the lumen of the hub203is in fluidic communication with the plenum inside the seal housing200and gas may flow into the access port. The application of a compressive force or a force tangential to the cylindrical wall284of the seal housing200such as by pressing the first projection155and the second projection400together such as by placing one finger on the first projection155and another finger on the second projection400and squeezing or pressing rotates the seal housing200relative to the cannula151, thereby converting the access device150from an open to a closed configuration as shown inFIG. 23wherein the projections155,400are close together. Of course to open the valve again force is applied to space apart the projections155,400. Apertures402,403are formed in the first and second projections155,400, respectively, and adapted for robotic control and manipulation of the projections into the open and closed positions. In contrast to the variation shown inFIGS. 10-20, the second projection400in the variation shown inFIGS. 21-23is not the connecting hub203but a separate projection formed on the seal housing. The open valve position indicated by indicia401being in alignment with the hub203can correspond with the second projection400being midway between the first projection155and an additional third projection156as shown inFIG. 21, or alternatively, the open valve position indicated by indicia40being aligned with the hub203can correspond with the second projection400being adjacent to the third projection156as shown inFIG. 22or, of course, adjacent to the first projection155. Either way, force is applied to move the projections156,400and rotate the seal housing200relative to the cannula151to open the valve as shown inFIG. 22, which may also correspond to a closed position in another variation. Likewise force is applied to move the projections400relative to the other one of the two projections155,156. Of course, force may be applied to separate or spread apart the projections400,156from the position shown inFIG. 22to a position shown inFIG. 21.

In another variation, the surgical access device includes an elongate tubular cannula having a lumen extending between an open proximal end and an open distal end. A seal housing is connected to the proximal end of the cannula. The seal housing includes an access channel at the proximal end arranged to be coaxial with the lumen of the cannula and providing access to the cannula lumen. The seal housing includes an outer side wall having a first opening movable relative to an inner side wall having a second opening. At least one seal is disposed inside the seal housing. The first and second openings are configured to align at least in part to fluidly connect the cannula lumen across the seal housing with outside the device. A port on the outer surface of the outer side wall at the location of the first opening is adapted to connect to a source of fluid under pressure for delivering fluid to and from the cannula lumen along the first and second openings when the first and second openings are at least in part aligned. The degree of fluidic communication can be regulated by selective alignment of the first and second openings. For example, partial alignment will provide low fluid flow relative to full alignment of first and second openings having coincident geometries which will provide greater fluid flow. The outer side wall is movable relative to the inner side wall between an open configuration and a closed configuration. In the open configuration, the first opening is in alignment at least in part with the second opening, thereby, fluidly connecting the cannula lumen across the seal housing. In the closed configuration, the first opening is offset from the second opening, thereby, closing fluidic communication across the seal housing. The seal housing includes a plenum distal to the at least one seal disposed inside the seal housing. The first and second openings are located along the seal housing for fluidic communication with this plenum which in turn is in fluid communication with the cannula lumen such that fluid flow across the seal housing into the plenum and into the cannula lumen. The outer side wall of the seal housing is longitudinally movable or rotatably movable relative to the inner side wall. The inner side wall and outer side wall are sealingly engaged such as by an O-ring seal such that no fluid escapes between the first and second side walls except through aligned first and second openings. The top of the seal housing includes a cap that includes an opening coaxial with the access channel of the seal housing. An internal ledge formed on the inside of the seal housing supports radially outwardly extending portion of the at least one seal and the cap captures the radially outwardly extending portion between the ledge and cap. The at least one seal includes a depending portion that is free to pendulate inside the seal housing and a spring biases both longitudinal and lateral translation of the seal. The spring may be tapered as will be described below.

The illustrated configuration defines an integral valve for the inflation port203, thereby, obviating the need for an external valve or stopcock, thereby, reducing the radial size of the seal housing200. The reduced radial size provides greater freedom in positioning the access device150, for example, tilted at a greater angle, and/or closer to another instrument and/or access device. In the illustrated variation, opening and closing the integral gas valve is a one-handed operation, in contrast with some external valves in which two hands are typically used, thereby permitting a user to opening or close the gas valve while manipulating an instrument therein. Moreover, the traction features permit a user to position the access device150, for example, advancing, withdrawing, rotating, and/or tilting, while opening and/or closing the gas valve.

Those skilled in the art will understand that in other variations, the seal housing is disposed within and sealingly rotatable within side wall of the cannula instead of around the side wall of the cannula. In some of these variations, the connecting hub is disposed on the side wall of the cannula and the side opening is disposed on the seal housing.

FIGS. 24-28illustrate another variation of an access device that is similar to the variation described above and illustrated inFIGS. 10-23. The illustrated variation further comprises a resilient support member350disposed between the seal members300,320and the cannula280and seal housing200. In the illustrated variation, the resilient member350comprises a tapered, helical coil spring disposed around and surrounding the seal members300and320. A smaller diameter, proximal end355of the resilient member350contacts and surrounds proximal portions305of the seal members300and320, while a larger diameter, distal end356contacts and rests upon a proximally facing surface271of the cannula base floor280. The spring350is disposed under a light compressive load between a first end355and a second end356thereof when placed inside the seal housing200. The proximal end355of the resilient member350abuts the radially extending portion301of seal member300which in turn contacts the radially extending portion321of seal member320. The distal end356abuts the proximally facing surface271of the cannula base floor280. In use, when an instrument is inserted into the working lumen, friction between the instrument and the seal will move the seal in the same direction as the instrument and result in stretching of the seal material and/or deflection of the seal material near its point of fixation along the radially extending portions301,321or anywhere on the seals300,320. With the resilient member350, the narrow proximal end355closely surrounds the portion of the seal that depends distally into the lumen. With the resilient member350slightly compressed inside the seal housing a spring bias force is applied onto the radially extending portions301,321to bias any force in a distal direction from an inserted instrument. In use, inserting an instrument through the seal members300and320applies a linear load on the spring350, thereby, compressing the spring350, which reduces or prevents excessive stretching of the radially extending portions301,321of the seal members300,320, respectively. Also, when the instrument is removed, that is, moved in a proximal direction, friction between the seal and the instrument may tend to pull the seal along with the instrument in a proximal direction. The wide distal end of the resilient member350permits pendulation of the seal at the distal end but also the resilient member350biases extreme deflection or pendulation toward the longitudinal axis of the lumen and thereby reducing frictional forces between the seal and instrument or reducing stretching and potential tearing of the seal material. After the linear load is removed, the spring350returns to the original, lightly-compressed condition, thereby, allowing the seal members300and320to pendulate freely. Those skilled in the art will understand that in other variations, the resilient member comprises another structure known in the art, for example, an elastomeric element, a pneumatic element, a hydraulic element, and the like, either individually, or in combination.

While certain variations have been particularly shown and described with reference to exemplary variations thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope thereof as defined by the following claims.