Abstract:
According to the present invention, improved methods and apparatus are provided for regaining hemostasis or otherwise minimizing leakage during endoluminal, surgical or percutaneous intraluminal procedures, and for providing a seal during laparoscopic surgical procedures where there is leakage of the CO 2  insufflation, when the primary means of hemostasis or pneumatic CO 2  seal is compromised or fails. More particularly the present invention relates to devices having a front hub and a rear hub, one or other of which is adapted to retain a compression seal such that when the front and rear hub are matingly engaged, axial and radial pressure is applied to the compression plug and any devices located therebetween, thereby achieving a seal. The compression device can be applied while a guidewire or additional devices remain within the leaking sheath or trocar, thereby allowing the physician to maintain hemostasis or adequate CO 2  insufflation, without exchanging the introducer sheath or laparoscopic port.

Description:
This application claims benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/182,640, filed Feb. 15, 2000, and which is incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to medical devices and methods and more particularly to devices and methods for sealing the lumen of a medical device for maintaining hemostasis (control of bleeding) attendant to the use of minimally invasive transluminal, endoluminal and other such devices and procedures wherein devices such as sheaths, through which other catheter devices are passed, are inserted percutaneously or surgically into a blood vessel of a patient, or in cases of laparoscopic procedures where sealing the lumen is to control the leakage of CO 2  gas used to insufflate a body cavity. 
     Minimally invasive interventions have become increasingly popular for approaching a variety of diseases such as the diagnosis and treatment of coronary heart disease using stent devises, laparoscopic procedures in general surgery, neurovascular disease for implanting coils, stents and other procedures, venous disease for placing vena cava filters or other procedures, as well as treatment of abdominal aortic aneurysms using stent grafts that are placed in the aorta or other vessels. The sizes of the catheter devices used to perform these therapies can range from 3 French to 30 French (0.039″ to 0.393″). Typically the devices that are used are within a 7 to 24 French (0.066″ to 0.315″) diameter. 
     In procedures such as these, a device known as an access sheath, also known as an introducer sheath, is typically placed through the skin in the upper thigh area of a patient&#39;s leg, either through a surgical cutdown or a percutaneous puncture, and down into the lumen of a blood vessel (vein or artery) with a technique known as the Seldinger technique (physician uses the “flashback” or blood spurt to confirm that the center of the lumen has been reached by the device), once a sheath is placed, most procedures employ catheter devices that are then inserted through the sheath and into the blood vessel at some distance away from the intended treatment site, and are then advanced through the vessel lumen until the selected treatment location is reached. In most instances this approach is performed “over the wire”, a technique that requires the physician to first place a guidewire device through the sheath and into the vessel lumen over which the larger catheter device can be tracked to the remote location. 
     The access sheaths that are employed for initial entry into the vessel typically include an integral hemostasis valve of some kind on the proximal portion of the device. There are numerous designs, including “duck-bill” type valves, valves that stretch and re-coil to accommodate various devices such as “iris” type valves, and various perforated elastomer valves. For example, U.S. Pat. No. 4,436,519 discloses a removable hemostasis valve having a “duck bill” type construction. U.S. Pat. No. 5,685,858 discloses a sliding valve for use with a catheter when no sheath is used. U.S. Pat. No. 4,738,658 discloses a tapered valve for use when a sheath is removed. U.S. Pat. No. 5,423,762 discloses a modular catheter sheath introducer with a replaceable hemostasis valve. During a procedure, however, these valves can fail, leading to leakage around the catheter and the valve, resulting in increased blood loss. 
     Given the popularity of less invasive techniques and their success, a broad range of devices or varying diameters are being used through sheaths, and the procedures are becoming increasingly complex and time consuming, making hemostasis over the duration of the procedure of paramount importance. A common problem during these procedures is a “leaky valve”, or the inability to maintain hemostasis around the catheter or wire using the integral sheath valve. In many procedures using larger devices such as aortic stent grafting, leaking valves can be quite commonplace. Currently, some surgeons and interventionists (radiologists, cardiologists) resort to tying gauze strips around the leaking section in an attempt to stem the flow of leaking blood. Typically the gauze just absorbs the blood and does not provide a durable solution. Various attempts have been made to come up with an improved integrated valve to deal with these issues with limited success. 
     There is a need for improved ancillary devices and methods for more effectively maintaining hemostasis, often after the existing valves have degenerated during a procedure, either due to multiple catheter exchanges (a time during the procedure when no catheter is in place and only a guidewire remains in the sheath), or the use of large catheter devices such as during the placement of stent grafts (some up to 32 French). It would be desirable to have an ancillary device that allows a physician to quickly regain hemostasis during the procedure thereby minimizing blood loss, while still being able to pass additional devices through the indwelling sheath once the ancillary device is placed, and complete the procedure as intended. 
     It would be desirable to have a device that can be applied to an existing sheath device to provide axial compression along the shaft of the sheath device and radial pressure around any devices introduced through the sheath, to block any leakage that may be flowing from the compromised valve at the proximal end of the sheath. Such a device would need to accommodate a guidewire and other catheters to pass through it so that the procedure can be completed. In addition, it would be desirable for such a compression device to be fixedly connected to said sheath during the time when hemostasis is desired, but also be removable from the sheath device in the event that the sheath is removed or changed during the procedure, or is no longer necessary. 
     Furthermore, it would be desirable to have a system of devices and methods that are easily applied around an indwelling sheath, either by the physician or the assisting staff, and that do not add unacceptable bulk to the catheter body already in place against the patient&#39;s skin. It is desirable that such improved devices be cost effective and adaptable to accommodate various sheath sizes, while still allowing the physician to pass additional catheters and instruments through the ancillary devices while continuing to minimize blood loss. 
     It would be further desirable to apply the compression device of the present invention to achieve hemostasis without requiring the removal of any indwelling instrumentation (such as catheters and guidewires), or having to thread such compression device over the entire length of the indwelling instrumentation to reach the desired point of hemostasis. 
     SUMMARY OF THE INVENTION 
     These and further objectives and advantages are met by the design and use of the various embodiments of the present invention. The present invention provides for improved methods and apparatus for providing a seal around a primary treatment device, such as, for example, regaining hemostasis during an intraluminal procedure when the primary means of hemostasis is compromised or fails, or in the case of laproscopic procedures, to control leakage of gas used to insufflate a body cavity. For purposes of this specification, the terms “standard introducer sheath” or “catheter”, or “integral valve”, “laparoscopic trocar or port” or “guidewire” shall all refer to primary treatment devices that have been placed in the patient prior to a medical procedure or during the procedure, usually endoluminally or percutaneously. Usually a standard introducer sheath will have an integral valve or elastic orifice at the proximal end to aid in hemostasis, but still allow the passage of therapeutic or diagnostic devices therethrough. In some instances, a sheath is not used, and therefore the therapeutic device may be a primary treatment device itself, such as a catheter with a valve. It should be noted however, that in the case of a procedure performed without a sheath the device of the present invention may be applied as the primary means of sealing by way of attachment around the proximal portion of the treatment device, such as a laparoscopic trocar or an endoluminal stent graft delivery device. 
     To achieve such sealing, the invention provides for a compressible, resilient plug that is adapted for positioning at the proximal end of a sheath device, i.e., an introducer sheath or other primary treatment device described above. The plug includes a slit extending longitudinally of the plug and opening to an outer surface of the plug in order to receive a therapeutic or diagnostic device, such as a catheter, guidewire, trocar, etc., that is operationally passed through the sheath device. The invention further provides means for compressing the plug, thereby providing axial pressure against the sheath device as well as radial inward pressure against the therapeutic or diagnostic device to maintain a seal and minimize leakage from the sheath device. 
     In particular, in a first embodiment of the present invention a compression device is provided having a rear hub and a front hub adapted to be placed around the shaft of a standard introducer sheath proximal end. The front hub and rear hub are operatively connected to two or more ratchet projections extending from one or other of the hubs, and adapted to be engaged into slots housed on the other hub. The compression device is preferably formed in a substantially cylindrical configuration having a longitudinal opening at some point around the circumference of the device for receiving the shaft of a standard catheter device from a sideloading position. The front hub preferably has at least two receiving slots formed in the sidewall thereof and defined further by release tab members extending therefrom. The rear hub includes two or more longitudinal projecting elements adapted for mating engagement with the front hub receiving slots. The rear hub further comprises a housing to receive a compression plug valve of the present invention. 
     In an alternate embodiment of the present invention, the compression device has a single ratchet mechanism. The combination of the front and rear hub is achieved by interlocking a ratcheting member shaft adapted to extend longitudinally from the front hub, and a corresponding ratchet member shaft extending longitudinally from the rear hub, said rear hub further having a through hole at the base of the rear hub, to receive the shaft of the front hub ratchet member. 
     In a further alternate embodiment of the present invention, the front and rear hub matingly engage upon insertion of the front hub into the cylinder of the rear hub (or vice versa), each hub including a threaded surface on either the inside or outside of the cylinder of the hub, depending on which one is to be inserted into the other. 
     In a further alternate embodiment, the compression device of the present embodiment is configured in the arrangement of a side-loading clamp, having a front portion and a rear portion and adapted to fit over the proximal end of a standard sheath and integral hemostasis device. This embodiment includes a front clamp to stabilize the compression device around the shaft of the standard introducer sheath or catheter, and an independently operating rear clamp having a housing for a compression plug, once the rear clamp is placed around the proximal portion of the introducer sheath and up against the integral valve, the compression plug operates to seal off any leakage. 
     In an exemplary use of the present invention, upon noticing that the hemostasis valve of the standard sheath (inserted in the patient) has begun to leak, a physician or assisting staff member will take the compression device of the present invention and place the introducer sheath catheter shaft and the proximal portion of the introducer sheath (usually valve end) into the longitudinal openings of the front and rear hub of the present invention, respectively (e.g. side loading the catheter shaft into the compression device). The operator will then operate the compression device of the present invention to engage the front and rear hub, bringing the compression pad of the present invention into contact with the leaking end of the introducer sheath, thereby applying axial pressure along the shaft of the introducer sheath and compressing radially around any device inserted therethrough, and abating any fluid flow from the sheath valve. The rear hub and compression device are adapted to receive a guidewire and other devices and therefore, the medical procedure already in process may then resume through the existing introducer sheath and the compression device of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B illustrate a top view and side view of a standard sheath and catheter system placed in the upper thigh of a patient to illustrate the relative placement of the sheath system to the leg of the patient. 
     FIG. 2 illustrates a standard percutaneous entry site into the leg of a patient with a generic sheath having an integral hemostasis valve on the proximal portion thereof. In addition a guidewire is shown through the lumen of the valve and the resultant leak. 
     FIG. 3 illustrates a schematic assembly of the present invention depicting the application of axial pressure against the proximal face of the generic hemostasis valve using a pressure plate and compression plug of the present invention. 
     FIG. 4 is a schematic representation of the device of the present invention in use over a standard introducer sheath device proximal end. 
     FIG. 5 illustrates a first embodiment of the present invention having a front hub and a rear hub connected to longitudinal ratchet projections that run on opposing sides of the rear hub such that when connected the device of the present invention may be placed around the proximal portion of standard introducer sheath. The rear hub further including housing for purposes of receiving a compression plug of the present invention. 
     FIG. 5A illustrates another embodiment of the present invention where the front hub portion of FIG. 5 is integral to an introducer sheath. 
     FIG. 5B illustrates a modified version of the compression plug of FIG.  3 . 
     FIG. 6 illustrates a another embodiment of the present invention having a front hub and a rear hub connected to each other by a single ratchet projection on the front hub positioned to be received by the rear hub such that when connected, the device of the present invention may be placed around the proximal portion of a standard introducer sheath. 
     FIG. 7 illustrates a further alternative embodiment of the present invention having a front hub and a rear hub connected to each other by interlocking threads (internal and external) disposed on the shafts of said front and rear hubs. 
     FIG. 8 illustrates still a further alternative embodiment of the present invention having a first and second clamp member pivotally attached to each other for purposes of placing said clamp members around the circumference of a standard introducer sheath proximal end. Said rear clamp member includes a housing to receive a compression plug of the present invention. 
     FIG. 9 illustrates an embodiment of the present invention wherein the body of the sealing device of the present invention is an integral unit. 
     FIG. 10 illustrates the present invention as applied to the main body of a laparoscopic trocar device to seal the trocar port while still allowing the placement of laparoscopic instruments therethrough. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1A and 1B are provided to illustrate the standard placement of an introducer sheath or endovascular or interventional catheter through a “groin incision” or puncture in the upper thigh of a patient. FIG. 1B illustrates a top view of an entry site (E), through which an introducer sheath (IS) has been placed, the introducer sheath IS including an integral hemostasis mechanism (H) and a through element such as a catheter or guidewire (C) extending therethrough. FIG. 1A illustrates a side view of the same standard placement of introducer sheath (IS) and catheter (C) with integral hemostasis sheath to show the angle of the catheter relative to the patient&#39;s limb. As seen, due to the limited access space between the patient&#39;s limb and the catheter C, it is desirable that the device of the present invention be of a low profile construction for integration with the existing sheath. 
     In the case of the placement of the IS through the entry site (E) of a patient as illustrated in FIG. 2, the integral hemostasis sheath may deform or otherwise become incompetent such that hemostasis is compromised and leakage (L) of blood results. This can be caused by multiple “exchanges” or insertions of various catheter devices of varying diameters (guidewires, therapeutic devices such as angioplasty balloons, stents, or stent grafts, or other such treatments) through the indwelling sheath during the course of a treatment. Typically such a standard introducer sheath (IS) includes a side port (SP) integral thereto that can connect the sheath to infusion, suction, or other functions. 
     FIG. 3 illustrates a schematic representation of the function of the present invention that operates to apply axial and/or radial compression to the introducer sheath (IS) at the point of the leak, that usually occurs at the rear portion of hemostasis sheath where devices are exchanged. In this schematic, the compression plug  10  is adapted to be applied, or “side-loaded”, over the wire by way of an axial slit  12  projecting from the central axis of the center of the compression plug  10 . In conjunction with the device of the present invention (shown in later figures), the compression plug  10  applies compression as represented schematically by pressure plate (PP) in this figure, when a force (F) is applied. 
     In operation, as illustrated in FIG. 4, the compression device of the present invention  20  is loaded from the side of the standard introducer sheath (IS) to accommodate the placement of the compression device against the thigh of the patient, and to accommodate the side port (SP) if present, and any therapeutic devices already residing in the sheath. As this Figure illustrates, the compression device  20  of the present invention, including compression plug  10 , is manipulated with a single hand of the operator and configured to extend on either side of the introducer sheath (IS) for ease of placement. 
     An exemplary compression device constructed in accordance with a first embodiment of the present invention is illustrated in FIG.  5 . The compression device  30  comprises a front hub  31  and a rear hub  32  adapted for operative engagement around the proximal portion of standard introducer sheath (IS). Front hub  31  is formed in a generally circumferential configuration having a lumen  31 ′ therethrough and extending along a longitudinal axis (L), and further defining an inner periphery  33  and an outer periphery  35 . Front hub  31  further includes a longitudinal opening  37  along the axis of front hub  31  allowing for placement of the hub body around the shaft of introducer sheath (IS). Front hub  31  further comprises one or more slots  39  formed within the inner periphery  33  and the outer periphery  35 . Front hub  31  also includes release tabs  41  and  43  extending laterally from said front hub  31  and subsequently in a curvilinear direction along the longitudinal axis of said front hub  31 . 
     Compression device  30  further comprises a rear hub  32  formed in a generally circumferential configuration having a lumen  32 ′ therethrough and extending along a longitudinal axis (L), and further defining an inner periphery  34  and an outer periphery  36 . Rear hub  32  further includes a longitudinal opening  38  along the axis of rear hub  32  allowing for placement of the rear hub body around the integral valve (H) of the introducer sheath (IS). Rear hub  32  includes a cavity  40  adapted to receive a compression plug  42  therein. Compression plug  42  is adapted to receive a guidewire or other catheter device by way of a slot  42 ′ extending laterally from the center of the plug. In a preferred embodiment slot  42 ′ includes a bevel  42 ″ to act as a channel for receipt of the guidewire (C) or other catheter and thereby guide the catheter to the center of the plug and aid the ease of application of the compression device  30  to the sheath (IS). Preferably the slot  42 ′ is aligned with the longitudinal opening  38  of the rear hub  32 . Compression plug  42  can be formed from various materials such as urethane, rubber (RTV), foam (opened or closed cell) or other elastomer, preferably silicone. The preferable dimensions of the plug are in the range of the diameter of 0.5″ to 1.5″. As shown in FIG. 5B, compression plug  142  can further be provided with protrusions  144 ,  144  located within slot  42 ′ and extending from the opposing slot faces. These protrusions are preferably formed of the same material as the plug itself, and operate to provide for increased sealing around the catheter when the plug is compressed during operation of the device, as further described. 
     Rear hub  32  further includes projection elements  44  extending from the outer periphery  36  along the longitudinal axis of the rear hub  32 , and adapted to be received by the slots  39  of front hub  31 . Projections  44  preferably have a serrated or ratchet surface on one or both sides to allow projections  44  to fixedly connect within the slots  39 . The preferred dimensions of the cavity  40  are such that the cavity accommodates most commercially available sheaths. 
     In operation, compression plug  42  is seated in cavity  40  and projections  44  are initially engaged by the operator with slots  39  to form an integral device (front and rear hub) that can be “side loaded” over the body of introducer sheath (IS) through longitudinal opening  37  of the front hub  31  and  38  of the rear hub and  32  of the compression plug  42 . The operator can then place preferably his or her index finger and middle finger on release tabs  41  and  43  respectively, and thumb on the proximal end of rear hub  32  and further engage the front and rear hub until the compression plug  42  exerts sufficient axial compression against the proximal valve (H) of introducer sheath (IS) and any existing leakage is stopped. To release the compression device of the present invention, the operator may place lateral digital compression against the release tabs  41  and  43 , thereby releasing the engagement of the ratcheting mechanisms of longitudinal projections  44  from slots  39 . Front hub  31  and rear hub  32  can then be separated and disengaged from introducer sheath (IS). It is contemplated as part of the present invention that compression device  30 , may be re-applied to the introducer sheath (IS) sometime later in a given procedure if necessary. 
     An alternate embodiment of the present invention is illustrated in FIG.  5 A. In this embodiment, features of the front hub described above are incorporated directly into introducer sheath  150  itself. As shown, projection tabs  143  extend from sheath  150  and include slots  139  for receiving corresponding projection elements of rear hub  44 . Sheath  150  can be assembled in a variety of ways, including integrally forming the sheath body, or otherwise assembling the sheath in ways known in the art. For example, that portion of the sheath containing the projection tabs and slots can be threaded onto the sheath body. 
     Front hub  31  is formed in a generally circumferential configuration having a lumen  31 ′ therethrough and extending along a longitudinal axis (L), and further defining an inner periphery  33  and an outer periphery  35 . Front hub  31  further includes a longitudinal opening  37  along the axis of front hub  31  allowing for placement of the hub body around the shaft of introducer sheath (IS). Front hub  31  further comprises one or more slots  39  formed within the inner periphery  33  and the outer periphery  35 . Front hub  31  also includes release tabs  41  and  43  extending laterally from said front hub  31  and subsequently in a curvilinear direction along the longitudinal axis of said front hub  31 . 
     Another embodiment of the compression device of the present invention is illustrated in FIG.  6 . In this embodiment, the compression device is provided with a single longitudinal front projection  61  extending from the front hub at a position at approximately 180° from the longitudinal slot  37  on front hub  31 . The rear hub  32  in this secondary embodiment is formed in a similar fashion as earlier described, but having a single longitudinal rear projection  62  provided with ratchet type indentations adapted for an interdigitating fit with front projection  61 . Rear hub  32  further includes a receiving slot  64  extending from the rear hub at a position at approximately 180° from the longitudinal slot  38  on front hub  31  for receipt of front projection  61 . In this secondary embodiment, compression plug  42  is adapted to fit within the cavity  40  of the rear hub, as earlier described. 
     In operation, longitudinal front projection  61  is placed in contact with longitudinal rear project  62  and thereafter guided into receiving slot  64  to slidably engage front hub  31  and rear hub  32  thereby bringing compression plug  42  into contact with the proximal end of introducer sheath (IS) and any other matter therebetween. 
     In an alternative embodiment of the present invention as illustrated in FIG. 7, the front hub and rear hub have a similar circumferential configuration as previously described. In this embodiment however, each hub has an extension of the hub body around its circumferential periphery that exhibits either an external or internal thread for operative engagement to each other. In FIG. 7, the front hub  31  includes an externally threaded extension  71 , extending beyond the front hub cup (adapted to fit around the shaft of an introducer sheath (IS)), the extension accommodating the continuation of the longitudinal opening  36  to accommodate side loading of the shaft of introducer sheath (IS). Similarly rear hub  32  includes internally threaded extension  72  that extends beyond the cavity  40  of rear hub  32  in sufficient length to engage the externally threaded extension  71  of the front hub when the compression device assembly is placed around the shaft and proximal portion of an introducer sheath (IS). As with the front hub in this embodiment, the rear hub extension  72 , accommodates the continuation of the longitudinal opening  37  to accommodate side loading of the proximal hemostasis portion (H) of introducer sheath (IS). 
     In operation, compression plug  42  is placed within the cavity of the rear hub, and the shaft and proximal end of the introducer sheath (IS) is side loaded into the lumen of the compression device  70 . The operator then slidably engages the extension  71  of the front hub and extension  72  of the rear hub until they are in fixed engagement due to the mating of the opposite threads located thereon. The rear hub  32  can be threaded rotationally with the front hub (e.g. screwed on), or can be simply pushed straight on so that the threads engage like a ratchet mechanism. To release, manual pressure can be applied to the sidewall of the front hub extension  71  to disengage the threads thereon from the thread of the rear hub extension  72 , or the rear hub can be rotationally removed by unscrewing it from the front hub. 
     In still a further embodiment of the present invention as illustrated by FIG. 8, the compression device  80  has a first and second clamp member  81  and  82  respectively, pivotally engaged for placement over an introducer sheath (IS) for purposes of applying circumferential and axial pressure against the leaky portion of the sheath. Front clamp body  81  has a first and second jaw portion  83 ′ and  83 ″ formed in a circumferential configuration for receipt of the sheath (IS) shaft. The first and second jaw portions  83 ′ and  83 ″ include finger tab portions  85  and  85 ′ extending bilaterally below the front clamp body. Finger tab portion  85  and  85 ′ are operatively connected by a spring member  87 , adapted to be placed in tension between finger tab portions  85  and  85 ′ to apply circumferential pressure against the sheath portion inserted in the front clamp body  81 . Front hub  81  can be released by applying manual pressure to pinch finger tab portions  85  and  85 ′ toward one another. 
     Rear clamp body  82  has a first and second jaw portions  84  and  84 ′, formed in a substantially circumferential configuration to accommodate both a compression plug  42  against the proximal end thereof, and the proximal sheath hemostasis portion (H) more distally. As with the front clamp body, rear clamp body  82  includes a finger tab portion  84  and  84 , extending bilaterally below the rear clamp body. Finger tab portion  84  and  84 ′ are operatively connected by a spring member  86 , adapted to be placed in tension between finger tab portions  84  and  84 ′ to apply circumferential pressure against the proximal sheath portion inserted in the rear clamp body  82 . In addition to the circumferential pressure exerted thereon, the rear hub portion is adapted to include a flange portion  88 , against which the compression plug  42  rests when positioned in the clamp cavity, to urge the compression plug  42  axially against the rear portion of the introducer sheath (IS) thereby applying direct pressure to any hemostasis device located therebetween. Rear hub  82  can be release by applying manual pressure to pinch finger tab portions  84  and  84 ′ toward one another. 
     Front clamp portion  81  and rear clamp portion  82  are pivotally connected by a central pivot rod  90  to which the apex of each bilateral finger tab portion is attached. The front and rear clamp portion of this embodiment can be operated independently of each other depending on the preference of the operator, however, each clamp operates around the same pivot axis (PA) to assist in optimal hemostasis. 
     FIG. 9 illustrates a schematic of the device of the present invention wherein the body of the device is constructed in an integral configuration, either as a one piece device, or separate elements secured together. The body portion  100  has a front hub portion  101  extending laterally from the main body portion  103  with a slot  105  located therein for receipt of the instrument (IS′) shaft and a rear hub portion  102  extending laterally from the main body portion  103  at some distance away from the front hub portion, and also including a slot  104  to allow instruments to still be passed through the indwelling instrument following application of the device of the present invention. In the case of the device that is constructed in one piece the main body and front and rear hubs may be formed of a resilient material, the front and rear hub portions being biased toward each other in the relaxed configuration and put in tension to install the device around an instrument. In the case of the device that is integrally formed from multiple elements, the main body portion may be a resilient element such as a longitudinal spring or multiple springs that in the relaxed position force the front and rear hub together. 
     In operation, the tension would be momentarily applied to the main body portion by pulling the front and rear hubs in opposite directions (to allow placement of the front and rear hubs around the shaft and proximal end of an introducer sheath) and releasing said tension to allow the front and rear hub to resiliently compress, thereby exerting a sealing force against each other and any devices or material trapped therebetween. The assembly view of FIG. 9 shows the application of the integral device of this embodiment, including compression plug  42  inserted between the rear hub portion  102  and the proximal part of the leaking instrument. 
     In still a further embodiment, FIG. 10 illustrates the use of the present invention for sealing CO 2  gas leaks at the port of a laparoscopic trocar device. The front hub  91  is provided with flexible clamping fixtures  93  adapted to clamp onto the main body of the laparoscopic device (MB). As described in the earlier embodiments, front hub side slots  95  and release levers  97  located on either side of the front hub body  91 , for connecting with the rear hub  92 . Similar to the description in earlier embodiments, rear hub  92  is formed in a hemispherical configuration with an inner and outer periphery. The inner periphery of rear hub  92  forms a cavity  94  for housing the compression plug  42 . The outer periphery of rear hub  92  includes projections  96  that extend laterally from rear hub  92  and then longitudinally along the axis of the center lumen of rear hub  92 . In operation front hub  91  would be secured to the main body of the trocar device (MB), and rear hub  92 , housing compression device  42 , would be advanced such that the projections  96  are slidably received by slots  95  of front hub  91  until the desired hemostasis is achieved. 
     The typical diameter of a laparoscopic trocar device ranges in the dimensions of 1.0″ to 2.0″. 
     While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the present invention, which rather are defined by the accompanying claims.