US20200077905A1 - Devices and methods for measuring portal pressure - Google Patents

Abstract

A system for measuring a pressure in a vein includes a needle sized and shaped to be inserted through a working channel of an endoscope. The needle is extending longitudinally and including a channel extending longitudinally therethrough. The system also includes a pressure sensing device including a longitudinally extending body sized and shaped to be slidably inserted through the channel of the needle and a sensor mounted on a distal portion of the body and connected to a proximal portion of the pressure sensing device via a connection cable. The sensor is configured to detect information corresponding to a pressure of a flow of blood through a vein.

Description

PRIORITY CLAIM
• The disclosure claims priority to U.S. Provisional Patent Application Ser. No. 62/728,528 filed Sep. 7, 2018; the disclosure of which is incorporated herewith by reference.
BACKGROUND
• Portal pressure is used to understand and manage hypertension, for example, in patients with liver cirrhosis. Currently, a measure for portal pressure is extrapolated by calculating a patient's hepatic venous pressure gradient (HVPG). A balloon catheter with sensing capabilities is used to measure a free hepatic venous pressure and a wedged hepatic venous pressure. The HVPG is calculated by taking a difference between the free and wedged hepatic venous pressures. The procedure for placing the balloon catheter, however, is an invasive trans-jugular approach, which provides only an approximated value for the portal pressure.
SUMMARY
• The present embodiments are directed to a system for measuring a pressure in a vein, comprising a needle sized and shaped to be inserted through a working channel of an endoscope, the needle extending longitudinally and including a channel extending longitudinally therethrough, and a pressure sensing device including a longitudinally extending body sized and shaped to be slidably inserted through the channel of the needle and a sensor mounted on a distal portion of the body and connected to a proximal portion of the pressure sensing device via a connection cable, the sensor configured to detect information corresponding to a pressure of a flow of blood through a vein.
• In an embodiment, the pressure sensing device may be longitudinally movable relative to the needle between an insertion configuration, in which the sensor is covered via a portion of the needle, and a pressure sensing configuration, in which a distal end of the body of the pressure sensing device extends distally past a distal end of the needle to expose the sensor to a flow of fluid within the vein.
• In an embodiment, the distal end of the needle may include a sharp tip for piercing a wall of the portal vein and the distal end of the body of the pressure sensing device may include a blunted end so that, in the insertion configuration, the distal end of the body is positioned relative to the sharp tip of the needle to prevent the sharp tip from damaging the working channel of the endoscope.
• In an embodiment, the pressure sensing device may be proximally movable relative to the needle so that the sharp tip is exposed to pierce a wall of the vein.
• In an embodiment, the distal end of the body of the pressure sensing device may include a sharp tip and the distal end of the needle may be blunted so that, in the insertion configuration, the sharp tip of the pressure sensing device is housed within the channel of the needle, and, in the pressure sensing configuration, the pressure sensing device is moved distally relative the needle, exposing the sharp tip of the body to pierce a wall of the portal vein.
• In an embodiment, in the pressure sensing configuration, the distal end of the body may be moved distally past the distal end of the needle via a predetermined distance. The pressure sensing device may include fins coupled to the body so that the fins are movable between a first configuration, in which the fins are constrained toward an exterior surface of the body in the insertion configuration, and a second configuration, in which the fins are moved radially outward to engage a portion of the needle in the pressure sensing configuration.
• In an embodiment, the system may further comprise a stylet sized and shaped to be inserted through the channel of the needle, the stylet being longitudinally movable relative to the needle between an insertion configuration and a piercing configuration.
• In an embodiment, a distal end of the stylet may include a sharp tip and a distal end of the needle may be blunted so that, in the insertion configuration, the sharp tip of the stylet is housed within the channel of the needle and, in the piercing configuration, the sharp tip of the stylet is moved distally past the distal end of the needle.
• In an embodiment, a distal end of the needle may include a sharp tip and a distal end of the stylet may be blunted so that, in the insertion configuration, the distal end of the stylet is positioned relative to the distal end of the needle to prevent the sharp tip of the needle from damaging the working channel of the endoscope and, in the piercing configuration, the stylet is drawn proximally relative to the needle to expose the sharp tip of the needle for piercing a wall of the vein.
• In an embodiment, the sensor may be mounted within a recess extending laterally into the body of the pressure sensing device along the distal portion thereof.
• In an embodiment, the body of the pressure sensing device may include a through hole extending laterally through the distal portion of the body so that a distal face of the sensor is exposed to a flow of fluid passing through the through hole.
• The present embodiments are also directed to a device for measuring a pressure within a vein, comprising a body extending longitudinally from a proximal end to a distal, the body sized and shaped to be inserted through one of a working channel of an endoscope and a channel of an endoscopic needle, and a sensor is positioned on a distal portion of the body, the sensor connected to a proximal portion of the device via a cable connection, the sensor configured to detect information corresponding to a pressure of a flow of blood through a vein.
• In an embodiment, the device may further comprise a working channel extending longitudinally through the body.
• In an embodiment, the sensor may be movable relative to the body between a first configuration, in which a portion of the sensor occludes a distal opening of the working channel extending through the body, and a second configuration, in which the sensor is moved away from a central axis of the body so that a tool inserted through the working channel of the body has a clear path for insertion into the vein.
• In an embodiment, the device may further comprise a cauterizing needle knife slidably housed within the body for creating a hole in a wall of the vein through which the body is insertable to measure the pressure of the vein.
• The present embodiments are also directed to a method for measuring a pressure in a vein, comprising inserting a needle through a working channel of an endoscope to a target area proximate a vein and piercing a wall of the vein and inserting a distal portion of a pressure sensing device into the vein to measure a pressure thereof, the pressure sensing device including a sensor mounted on the distal portion and connected to a proximal portion of the device via a connection cable.
BRIEF DISCLOSURE
• FIG. 1 shows a schematic view of a system according to an exemplary embodiment of the present disclosure;
• FIG. 2 shows a longitudinal side view of a distal portion of a pressure sensing device of the system ofFIG. 1;
• FIG. 3 shows a longitudinal side view of a distal portion of a pressure sensing device according to an alternate embodiment;
• FIG. 4 shows a schematic view of a system according to another exemplary embodiment of the present disclosure;
• FIG. 5 shows a schematic view of a system according to yet another exemplary embodiment of the present disclosure;
• FIG. 6 shows a schematic view of a system according to another exemplary embodiment of the present disclosure;
• FIG. 7 shows a schematic view of the system ofFIG. 6, including a pressure sensing device according to an alternate embodiment of the present disclosure
• FIG. 8 shows a schematic view of the system ofFIG. 6, including a pressure sensing device according to yet another alternate embodiment of the present disclosure;
• FIG. 9 shows a longitudinal side view of a distal portion of a system according to another exemplary embodiment of the present disclosure, in a first configuration;
• FIG. 10 shows a longitudinal side view of the distal portion of the system ofFIG. 9, in a second configuration;
• FIG. 11 shows a longitudinal side view of the distal portion of the system ofFIG. 9, in a third configuration;
• FIG. 12 shows a longitudinal side view of a distal portion a system according to an alternate embodiment of the present disclosure, in a first configuration;
• FIG. 13 shows a longitudinal side view of the distal portion of the system ofFIG. 12, in a second configuration;
• FIG. 14 shows a longitudinal side view of a distal portion of a system according to yet another exemplary embodiment of the present disclosure, in a first configuration;
• FIG. 15 shows a longitudinal side view of a distal portion of the system ofFIG. 14, in a second configuration;
• FIG. 16 shows a schematic view of a system according to another exemplary embodiment of the present disclosure;
• FIG. 17 shows a longitudinal side view of a pressure sensing device of the present disclosure according to another exemplary embodiment of the present disclosure;
• FIG. 18 shows a cross-sectional view of the pressure sensing device ofFIG. 17;
• FIG. 19 shows a longitudinal side view a pressure sensing device according to an alternate embodiment;
• FIG. 20 shows a cross-sectional view of the pressure sensing device ofFIG. 19;
• FIG. 21 shows a schematic view of a system according to yet another exemplary embodiment of the present disclosure;
• FIG. 22 shows a longitudinal side view of a system according to another exemplary embodiment of the present disclosure, in a first configuration;
• FIG. 23 shows a longitudinal side view of the system ofFIG. 22, in a second configuration;
• FIG. 24 shows an enlarged side view of a sensor of the system ofFIG. 22;
• FIG. 25 shows an enlarged end view of the sensor ofFIG. 24;
• FIG. 26 shows a schematic view of a passive senor according to an exemplary embodiment of the present disclosure; and
• FIG. 27 shows a schematic view of a passive sensor according to another exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
• The present disclosure may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present disclosure relates to systems and methods for measuring a portal pressure and, in particular, describes insertion of a pressure sensing device into the portal vein via a needle that is guided to the portal vein under endoscopic ultrasound guidance. The pressure sensing device is inserted directly into the portal vein to measure the portal pressure. Thus, the present disclosure provides a non-invasive system and method for providing an accurate measurement of the portal pressure. Although the exemplary embodiments specifically show and describe the pressure sensing device as including a sensor for measuring a pressure within the portal vein, the sensor may also measure additional information, in addition to pressure. Thus, it will be understood by those of skill in the art that the below-described systems and methods may also be utilized for obtaining and measuring information other than portal vein pressure. It should be noted that the terms “proximal” and “distal,” as used herein, are intended to refer to a direction toward (proximal) and away from (distal) a user of the device.
• As shown inFIG. 1, asystem100 for measuring a pressure within aportal vein10 according to an exemplary embodiment of the present disclosure comprises aneedle102 along with astylet104 and apressure sensing device106, each of which are passable through achannel108 of theneedle102.FIG. 1 further shows steps1-4 for gaining access into theportal vein10 using thesystem100. Initially, theneedle102, with thestylet104 received within thechannel108 to prevent tissue from entering thechannel108 during insertion, may be passed through a working channel of a flexible endoscope to be positioned proximate a patient'sportal vein10, as shown instep1. Once theneedle102 has been placed in a desired position proximate to the vein, thestylet104 may be removed therefrom, as shown instep2, and a sharpdistal tip110 of theneedle102 may be advanced to puncture awall12 of theportal vein10 so that a distal opening of theneedle102 is positioned within thevein10, as shown instep3. Upon gaining access to theportal vein10, thepressure sensing device106 is inserted through thechannel108 into theportal vein10, as shown instep4, so that apressure sensor112 in adistal portion114 of thepressure sensing device106 is exposed to the flow of blood through theportal vein10 to measure the pressure in thevein10.
• Theneedle102 extends longitudinally from a proximal end (not shown) to adistal end116 and includes thechannel108 extending therethrough. Theneedle102 is preferably flexible and is sized and shaped to be inserted through a working channel of a flexible endoscope and is particularly configured to be visible under ultrasound guidance so that theneedle102 may be guided to the desired position proximate theportal vein10. Thedistal end116 of theneedle102, in this embodiment, includes the sharpdistal tip110 to facilitate puncturing of theportal vein10.
• Thestylet104 extends longitudinally from a proximal end (not shown) to adistal end118 and is sized and shaped to be slidable within thechannel108 of theneedle102. Thedistal end118 is blunted so that, in an insertion configuration, thestylet104 is received within the channel of theneedle102 with the blunteddistal end118 aligned with thedistal end116 of theneedle102 or extending slightly distally beyond thedistal end116 of theneedle102 to minimize damage to non-targeted tissue as thetip110 of theneedle102 is moved to the target site adjacent to the vein10 (i.e., to prevent theneedle102 from inadvertently piercing or damaging tissue surrounding the path along which the needle is inserted to the target site and to prevent tissue from collecting within thechannel108 during insertion of theneedle102 to the target site.
• Thepressure sensing device106, in this embodiment, includes aflexible body120 and thepressure sensor112 positioned along adistal portion114 thereof. Those skilled in the art will understand that thebody120 preferably has a flexibility sufficient to enable thebody120 to be passed through the working channel of a flexible endoscope as the endoscope traverses a tortuous path to the target site adjacent to thevein10. Thebody120 extends from a proximal end (not shown) to adistal end122 and is sized and shaped to be slidably inserted into thechannel108 of theneedle102. Thepressure sensor112 may be connected to a proximal end of thedevice106 via, for example, aconnection cable124 or other data transmission medium extending proximally from thepressure sensor112 through and along a length of thebody120. Thepressure sensor112 may be an optical sensor or an electrical sensor. As would be understood by those skilled in the art, an optical sensor may require fluid to flow thereacross, which may be analyzed to calculate a corresponding pressure value while an electrical sensor may simply require contact with the blood within the vein to measure a blood pressure thereof. However, those skilled in the art will understand that any sensor capable of measuring the pressure within thevein10 may be employed and that the sensor may forward data to a data processing arrangement in any known manner including, for example, wireless, optical fiber and wired connections. Thepressure sensor112 may be housed within or mounted along thebody120 in any of a number of configurations as would be understood by those skilled in the art.
• In one embodiment, as shown inFIG. 2, thedistal portion114 of thebody120 includes arecess126 extending laterally thereinto and in which thesensor112 is positioned. Where thesensor112 is, for example, a diaphragm-based optical sensor, thesensor112 may include anangled diaphragm113 to allow for adequate flow thereacross. This configuration also permits adequate fluid contact where thesensor112 is an electrical sensor. In another embodiment, as shown inFIG. 3, adistal portion114′ of abody120′ of apressure sensing device106′ includes ahole126′ extending transversely therethrough so that fluid flows across adistal face113′ of asensor112′ housed within thedistal portion114′ via thehole126′. Thesensor112′, in this embodiment, may be, for example, an optical sensor with a distal-facing diaphragm. This embodiment may be particularly suited for reducing/preventing air bubbles from forming around thepressure sensor112′, which could lead to skewed pressure readings. A positioning ring may be housed within thedistal portion114′ to secure thepressure sensor112′ therewithin so that thepressure sensor112′ does not come into contact with any portion of thebody120′ which might cause damage thereto during insertion of thepressure sensing device106′ through even tortuous paths of the patient body.
• According to an exemplary technique using thesystem100, theneedle102, with thestylet104 received therewithin in the insertion configuration, is inserted through a working channel of an endoscope to a target area proximate aportal vein10. As would be understood by those skilled in the art, theneedle102 may be guided to theportal vein10 under, for example, EUS guidance via, for example, the stomach or duodenum. Once theneedle102 is in a desired position proximate theportal vein10, thestylet104 may be withdrawn from the channel of theneedle102 so that the sharp distal end of theneedle102 is exposed and theneedle102 may be moved distally to penetrate theportal vein10. Upon gaining access into theportal vein10 via theneedle102, the pressure sensing device may then be inserted throughchannel108 of theneedle102 until thepressure sensor112 extends distally beyond thedistal end116 of theneedle102 within the interior of theportal vein10. Thepressure sensor112 within theportal vein10 then provides a blood pressure measurement thereof. For example, as described above, a flow of blood within theportal vein10 along diaphragm of thepressure sensor112 or contact with fluid with thepressure sensor112 provides a reading for the pressure measurement. Once the pressure measurement of theportal vein10 has been obtained, theneedle102 and thepressure sensing device106 may be removed from the patient body. If desired, the pressure sensing device may optionally be removed from theneedle102 and thestylet104 may be reinserted to the insertion configuration as theneedle102 is withdrawn proximally back into the endoscope for removal from the body.
• Although thesystem100 is shown and described as including thepressure sensing device106 including thepressure sensor112 along thedistal portion114 of theelongated body120 thereof so that thepressure sensing device106 may be immediately removed from the body upon obtaining a pressure measurement, according to another exemplary embodiment, thesystem100 may include a pressure sensing device that is deployed within theportal vein10 to provide periodic monitoring of the portal pressure. In this embodiment, as shown inFIG. 26, a pressure sensing device includes apressure sensor112″, which may be pushed through theneedle102 and into theportal vein10 via, for example, thestylet104 or any other delivery device. Thepressure sensor112″ may be a wireless passive sensor including a resonant tank circuit of a parallel inductor and capacitor. In one embodiment, as shown inFIG. 26, the passive sensor may be formed in a 1 mm by 1 mm form using micro-machined traces for two parallel inductors sandwiching an insulating substrate. The parallel inductive traces can be used to create a parallel plate capacitance for the sensor. The passive sensor may be anchored within theportal vein10 via, for example, a nitinol anchor wire which may act as an inductor or a part of an inductor of the resonant tank circuit sensor. In another embodiment, as shown inFIG. 27, a capacitor may be micromachined on a polymer substrate which is attached to a loop wire.
• In one embodiment, the inductive wire or coil may be trace engineered to be several 10s of nH's. In one particular example, the inductance may be 47 nH. The capacitance should be as large as possible to ensure a lower resonant frequency given the physical constraints and, in one example, may have a minimal value of 1 pF. In one embodiment, the polymer substrate, which acts as an insulator, may be formed of a polymer that will give under pressure while maintaining a relative permittivity of greater than 4. According to one example, the polymer substrate may have a thickness of 10 um. In one embodiment, a high Q (quality factor) is desired and may be achieved by increasing the turns and splitting the coil evenly from the top and bottom layers, keeping the ratio of the L/C high. In one embodiment, a resonant frequency should be low enough to allow coupling from outside of the body (e.g., below 1 GHz) and keeping the form factor small enough so as not to interfere with the blood flow. In one embodiment, the resonant frequency may range from between 800 MHz to 1000 MHz.
• According to one example, a polymer made of flexible laminate may allow for a dielectric constant (e.g., 9 or 10) which allows for a high Q and smaller dimensions of the passive resonant circuit. A nitinol wire, which may be used to anchor the passive sensor, may allow more flexibility of the anchor. Controlling a length of the anchoring wire would allow for an inductor ranging in value from between 33-47 nH so that a parallel plate capacitor sensor on the end may be valued from between 0.8 pF to 1.2 pF in the space constraints of a disc having a size of 1 mm or smaller to resonate within a range of 800 MHz to 1000 MHz.
• Thepassive sensor112″ may be read, for example, by using a near field communication device that can be tuned to the resonant frequency of the passive circuit as it is deployed from the body. The resonant frequency will shift according to the change in pressure so that extrapolating the pressure is achieved from tracking the change in pressure deployed in the system versus its neutral state before being introduced into the system. In one embodiment, a near field communication device may be utilized via a smart phone. A device including a variation of a loop antenna multiplexed from transmit to receive with a voltage controlled oscillator and receiver will be attached to a smart phone and controlled by an application run on the phone. The application will detect peak output from the passive sensor and read the frequency setting while at peak. There will be a linear correlation to frequency and pressure when the passive sensor is fabricated. A calibration of the baseline frequency and sensitivity will be created during initial testing to be used in the application of the smart phone. A reading may be taken off the body by placing the smart phone near the target area until, for example, an optimal signal strength is indicated on the phone. Periodic readings of the frequency may be acquired to monitor changes in pressure.
• As shown inFIG. 4, asystem200 according to another exemplary embodiment of the present disclosure is substantially similar to thesystem100 described above, comprising aneedle202 and apressure sensing device206. Thesystem200, however, does not require a stylet, as shown in steps1-4 ofFIG. 4, to gain access to the interior of aportal vein20. Rather, thepressure sensing device206, which includes a bluntdistal end222, is received within achannel208 of theneedle202 during insertion of theneedle202 through a working channel of an endoscope to a target area proximate aportal vein20. Similarly to thestylet104 of thesystem100, thepressure sensing device206 of this embodiment is positioned within thechannel208 of theneedle202 so that the bluntdistal end222 of thepressure sensing device206 prevents tissue from entering thechannel208 and/or prevents thesharp tip210 of theneedle202 from damaging the working channel of the endoscope during insertion of theneedle202 therethrough and also prevents harm to non-targeted tissue as theneedle202 is extended distally from the endoscope.
• Theneedle202 and thepressure sensing device206 are substantially similar to theneedle102 andpressure sensing device106 of thesystem100. As described above, thepressure sensing device206 includes a bluntdistal end222 and prevents the sharpdistal tip210 of theneedle202 from damaging the working channel of the endoscope during insertion. Thus, in an insertion configuration, thepressure sensing device206 is positioned within theneedle202 such that a position of the buntdistal end222 is aligned with or protrudes slightly distally beyond the sharpdistal tip210 of theneedle202. Accordingly, in this embodiment, thepressure sensor212 must be positioned along a distal portion214 of alongitudinal body220 of thepressure sensing device206 such that, when thepressure sensing device206 is in the insertion configuration relative to theneedle202, thepressure sensor212 is covered by a portion of theneedle202. In other words, where the sharpdistal tip210 of theneedle202 is formed via a tapering at adistal end216 of theneedle202, thepressure sensor212 should be sufficiently distanced from thedistal end222 of thebody220 such that thepressure sensor212 is fully covered by a portion of theneedle202 regardless of a rotational orientation of thepressure sensing device206 within theneedle202.
• Thesystem200 may be used in a manner substantially similar to thesystem100. Theneedle202, however, is inserted to the target area with thepressure sensing device206 received therewithin in the insertion configuration, as shown instep1. Once theneedle202 has reached the target area, thepressure sensing device206 may be drawn proximally with respect to theneedle202 so that the sharpdistal tip210 of theneedle202 is exposed, as shown instep2. Theneedle202 is then advanced distally so that awall22 of theportal vein20 is punctured via the sharpdistal tip210 and theneedle202 extends into an interior thereof, as shown instep3. Upon gaining access to the interior of theportal vein20, thepressure sensing device206 is moved distally with respect to theneedle202 until thepressure sensor212 is extends distally past thedistal end216 of theneedle202 to measure pressure within theportal vein20, as shown instep4.
• As shown inFIG. 5, asystem300 according to another exemplary embodiment may be substantially similar to thesystem100 described above, comprising aneedle302, astylet304 and apressure sensing device306.FIG. 5 shows steps1-5 for gaining access into aportal vein30 using thesystem100. Similarly to thesystem100, theneedle302 may be inserted through a working channel of an endoscope to a target area proximate aportal vein30, with thestylet304 received therein, in an insertion configuration. In this embodiment, however, theportal vein30 is pierced via a sharpdistal tip318 of thestylet304 rather than via theneedle302.
• Theneedle302 may be substantially similar to theneedle102 described above. Adistal end316 of theneedle302, however, does not need to include a sharp tip. Thedistal end316 may, for example, include a distal face that extends substantially transverse to a longitudinal axis of theneedle302, as theneedle302 is not required for puncture theportal vein30.
• In this embodiment, thestylet304 may be substantially similar to thestylet104 described above with regard to thesystem100. Thestylet304, however, includes a sharpdistal tip318. The sharpdistal tip318 may be formed in any of a number of configurations. In one example, the sharpdistal tip318 may be formed via a tapered distal-facing surface extending at a non-perpendicular angle with respect to a longitudinal axis of thestylet304.
• In the insertion configuration, thestylet304 is received within achannel308 of theneedle302 so that thedistal tip318 is aligned with thedistal end316 of theneedle302 or slightly proximal thereto, as shown instep1. This prevents the sharpdistal tip318 of thestylet304 from damaging the working channel of the endoscope while also preventing any inadvertent collection of tissue therewithin. Once theneedle302 andstylet304 have reached the target are proximate theportal vein30, however, theneedle302 is drawn proximally relative to thestylet304 so that the sharpdistal tip318 of thestylet304 is exposed in a piercing configuration, as shown instep2. Theneedle302 andstylet304, in the piercing configuration, are moved distally until the sharpdistal tip318 of thestylet302 penetrates theportal vein30, as shown instep3. After thestylet304 has pierced theportal vein30, theneedle302 is advanced distally over thestylet304 to enter theportal vein30. After thedistal end316 of theneedle302 has been positioned as desired within theportal vein30, thestylet304 may be removed, as shown instep4 and, as shown instep5, thepressure sensing device306 may then be inserted through theneedle302 until apressure sensor312 mounted and/or positioned along abody320 of thepressure sensing device306 is exposed to the fluid flowing through theportal vein30 to generate a portal pressure measurement.
• As shown inFIG. 6, asystem400 may be substantially similar to thesystems200,300 described above. Similarly to thesystem200, thesystem400 comprises aneedle402 andpressure sensing device406, which may be used to access theportal vein40, as shown insteps1 and2 ofFIG. 6. Similarly to thesystem200, thesystem400 does not require a separate stylet as theneedle402 is inserted through a working channel of an endoscope to a target area proximate theportal vein40 with thepressure sensing device406 received therewithin in an insertion configuration. In this embodiment, however, theportal vein40 is pierced via a sharpdistal tip422 of apressure sensing device406, rather than via adistal end416 of theneedle402. Thus, theneedle402 is substantially similar to theneedle302, as described above with respect to thesystem300, which does not include a sharp distal tip.
• Thepressure sensing device406 may be substantially similar to thepressure sensing devices206 described above, comprising alongitudinally extending body420 and apressure sensor412 positioned along a distal portion414 thereof. Rather than a blunted distal end, however, adistal end422 of thebody420 includes asharp tip428, which may be formed via a tapering of thedistal end422. Thesharp tip428 may have any of a number of configurations. In one example, thesharp tip428 may he formed via a tapered distal-facing surface which extends at a non-perpendicular angle relative to a longitudinal axis of thebody420. In another example, as shown inFIG. 7, adistal end422′ of abody420′ of apressure sensing device406′ may be substantially conically tapered to form asharp tip428′. In yet another example, as shown inFIG. 8, adistal end422″ of abody420″ may include bluntededges430″ with thesharp tip428″ extending distally therefrom. Thesharp tip428″ may be substantially conically shaped. In both of the examples shown inFIGS. 7 and 8, thesharp tips428′,428″ are substantially centered relative to a longitudinal axis of thebody420′,420″, respectively. Since thesharp tips428′,428″ are centered, a likelihood of thesharp tips428′,428″ damaging the working channel of the endoscope is reduced so that, if so desired, the pressure sensing devices including thesharp tips428′,428″ may be inserted directly through the working channel of an endoscope, without the use of theneedle402, to gain access to the portal vein.
• As shown inFIGS. 9-11, asystem500 according to yet another exemplary embodiment of the present disclosure may be substantially similar to thesystems200,400 described above, comprising aneedle502 and apressure sensing device506. Theneedle502 and thepressure sensing device506, however, include additional features which allow theneedle502 and thepressure sensing device506 to interface with one another so that, when moved from an insertion configuration to a pressure sensing configuration, adistal end522 of thepressure sensing device506 moves distally beyond adistal end516 of theneedle502 by a predetermined distance. It will be understood by those of skill in the art that this feature may be useful for measuring the pressure within a portal vein since the portal vein is quite small in comparison to other veins. Thus, the predetermined distance between thedistal end522 of thepressure sensing device506 and thedistal end516 of theneedle502 in the pressure sensing configuration may be set so that, when the system is in the pressure sensing configuration in an operative position (i.e., in the portal vein), thedistal end522 of thepressure sensing device506 does not contact and/or pierce a far wall of the portal vein into which it has been inserted preventing damage to the portal vein.
• Theneedle502 may be substantially similar to either of theneedles202 or402, including achannel508 through which thepressure sensing device506 may be inserted. Thepressure sensing device506 may be substantially similar to either of thepressure sensing devices206 or406, including abody520 with a pressure sensor (not shown) positioned along a distal portion thereof. A distal end of either theneedle502 or thebody520 may include a sharp tip for piercing the portal vein and gaining access thereto. To prevent thepressure sensing device506 from moving beyond the predetermined distance relative to theneedle502, thebody520 includesfins532 movable between a constrained configuration, in which thefins532 are moved toward anexterior surface534 of abody520 of thepressure sensing device506, and a outwardly biased configuration, in which thefins532 are moved radially outward, away from theexterior surface534 of thebody520. When thefins532 are in the constrained configuration, thepressure sensing device506 may be received within thechannel508 of theneedle502 so that thesystem500 is in the insertion configuration. As thepressure sensing device506 is moved distally relative to theneedle502 toward the pressure sensing configuration, thefins532 revert to their outwardly biased configuration to engage a portion of theneedle502, thereby preventing further distal movement of thepressure sensing device506 with respect to theneedle502.
• Thefins532 may be constrained via an interior surface of thechannel508 of theneedle502, when in the insertion configuration. Upon moving thepressure sensing device506 distally with respect to theneedle502, thefins532 are freed to revert to their outwardly biased configuration to engage a distal portion of the needle502 (e.g., a recess or groove along a distal portion of the interior surface of the channel508), when in the pressure sensing configuration. In this embodiment, movement of thefins532 may be controlled via one ormore pull wires536 so that, if it is desired to draw thepressure sensing device506 back into theneedle502 toward the insertion configuration, thepull wire536 may be drawn proximally relative to thepressure sensing device506 so that thefins532 are moved toward the constrained configuration, and thepressure sensing device506 may be drawn back into thechannel508.
• According to another example, as shown inFIGS. 12-13, asystem500′ may be substantially similar to thesystem500, comprising aneedle502′ and apressure sensing device506′ including features which interface so that adistal end522′ of thepressure sensing device506′ is moved distally beyond adistal end516′ of aneedle502′ via a predetermined distance, when in a pressure sensing configuration. Similarly to thepressure sensing device506, abody520′ of thepressure sensing device506′ includesfins532′ movable between a constrained configuration and an outwardly biased configuration, in which thefins532′ engage a corresponding portion of theneedle502′ when in the pressure sensing configuration. Thefins532′ in the embodiment, however, are not controllable via pull wires. Rather, thefins532′ arc connected to thebody520′ and configured so that, when it is desired to move thesystem500′ from the pressure sensing configuration to the insertion configuration, moving thepressure sensing device506′ proximally relative to theneedle502′ causes thefins532′ to be constrained toward the constrained configuration so that thepressure sensing device506′ may be drawn into achannel508′ of theneedle502′.
• For example, aproximal end538′ of thefins532′ may be connected to thebody520′ so that adistal end540′ of thefins532′ are movable toward and away from aninterior surface534′ of thebody520′ in the insertion and pressure sensing configurations, respectively. Thefins532′ may be configured to engage a correspondingly sized and shapedgroove542′ along a distal portion of thechannel508′ in the pressure sensing configuration. Thegroove542′ may include, for example, anangled surface544′ extending proximally therefrom so that, when thefins532′ are slid proximally against theangled surface544′, thefins532′ are moved toward the constrained configuration so that thepressure sensing device506′ may be drawn proximally into thechannel508′ of theneedle502′.
• As shown inFIGS. 14-15, asystem500″ may be substantially similar to thesystems500,500′ described above, comprising aneedle502″ and apressure sensing device506″ including abody520″ withfins532″ for allowing adistal end522″ of thepressure sensing device506″ to move distally beyond adistal end516″ of theneedle502″ via a predetermined distance. Thefins532″ in this embodiment, however, are not movable. Rather, thesystem500″ is configured so that adistal end540″ of thefins532″ abuts against a radially inwardly extendingprotrusion542″ of achannel508″ of the needle” preventing any further distal motion of thepressure sensing device506″ relative to theneedle502″. Thus, the radially inwardly extendingprotrusion542″ of theneedle502″ acts as a stop preventing movement of thefins532″ of thepressure sensing device506″ distally therebeyond.
• Although the systems500 (along withsystems500′ and500″) specifically show and describefins532 for controlling a distance via which thedistal end522 of thebody520 of thepressure sensing device506 extends distally from thedistal end516 of theneedle502, it will be understood by those of skill in the art that the above-described systems may include in any of a variety of other features for controlling the distance via which thedistal end522 of thepressure sensor506 extends beyond thedistal end516 of the needle. For example, a handle member of thesystem500 may include features (e.g., a spring loaded slider, a slider with twisting lock, button) which causes thedistal end522 of thepressure sensing device506 to protrude from theneedle502 via a predetermined distance.
• As shown inFIG. 16, asystem600 according to another exemplary embodiment comprises apressure sensing device606 which, similarly to the pressure sensing devices described above, includes alongitudinally extending body620 with apressure sensor612 positioned along adistal portion614 thereof. Thepressure sensing device606, however, further includes aretractable needle knife646 longitudinally movably housed within thebody620 for cutting a small hole through awall62 of theportal vein60 to gain access thereinto. Since thepressure sensing device606 in this embodiment includes theneedle knife646 for gaining access to theportal vein60, a separate needle and/or stylet is not required.
• Thepressure sensing device606 may include alumen650 extending longitudinally though thebody620, within which theneedle knife646 is slidably received. Theneedle knife646 may be movable between an insertion configuration, in which adistal end648 of theneedle knife646 does not extend distally beyond adistal end622 of thebody620 of thepressure sensing device606, to a cutting configuration, in which theneedle knife646 is moved distally with respect to thebody620 so that thedistal end648 of theneedle knife646 extends distally beyond thedistal end622 of thebody620 to cut a small hole though thewall62 of theportal vein60. In one embodiment, thedistal end648 of theneedle knife646 may be sharp enough to create a small hole through the vein, through which thebody620 of thepressure sensing device606 may be inserted. In another embodiment, theneedle knife646 may utilize hot cautery to create a small hole through thewall62 of theportal vein60. Theneedle knife646 may be able to create a smaller hole in thewall62 of the portal vein than one formed via a conventional needle, which may be advantageous depending on the level of disease the patient is experiencing.
• FIG. 16 shows steps1-4 for gaining access to aportal vein60 using thepressure sensing device606. Thepressure sensing device606 may be inserted directly through a working channel of an endoscope to a target area within a patient body, with theneedle knife646 housed within thebody620, in the insertion configuration. As shown instep1, adistal end622 of abody620 of the pressure sensing device is positioned proximate awall62 of aportal vein60 in a target position. Once thepressure sensing device506 is in the target position, theneedle knife646 is moved from the insertion configuration to the cutting configuration, as shown instep2. Thedistal end648 of theneedle knife646 may then be used to a form a small hole in thewall62 of theportal vein60, through which thedistal end622 of thebody620 may follow through, as shown instep3. As shown instep4, thebody620 is inserted through the small hole until thepressure sensor612 is exposed to a flow of blood through theportal vein60. Once theportal vein60 has been accessed by thebody620, theneedle knife646 is retracted into the body toward the insertion configuration to prevent damage to theportal vein60 as the pressure reading is being taken.
• Although thepressure sensing device600 is shown and described as being inserted directing through the working channel of the endoscope to gain access to theportal vein60, it will be understood by those of skill in the art that thepressure sensing device606 may also be utilized with a needle, substantially as described above with respect to thesystems200,400. Inserting thepressure sensing device606 with a needle may be particularly useful where there is concern regarding accessing the portal vein through the stomach or duodenum. Theneedle knife646 may be used to access the vein once the needle is in the liver, reducing potential bleeding.
• As shown inFIGS. 17-18, apressure sensing device706 according to another exemplary embodiment may be utilized in any of the systems100-500, as described above. Thepressure sensing device706 may be substantially similar to the pressure sensing devices106-506 including alongitudinally extending body720 including apressure sensor712 positioned along adistal portion714 of thebody720 and connected to a proximal portion of thepressure sensing device706 via a connection cable724 (e.g., electrical, optical fiber) extending proximally from thepressure sensor712 along a length of thebody720. Thepressure sensing device706, however, further includes a workingchannel752 extending through thebody720 so that other diagnostic and/or therapeutic tools may be inserted through the workingchannel752 into the portal vein. The workingchannel752 may extend along an axis substantially parallel to a central longitudinal axis of thebody720.
• Thepressure sensor712 may also be offset from the central longitudinal axis of thebody720 so that theconnection cable724 extends substantially parallel to the central longitudinal axis of thebody720. In one embodiment, thepressure sensor712 may have a distal-facingdiaphragm713 and/or reading surface such that the pressure sensor is mounted within adistal end722 of thebody720 so that the distal-facing diaphragm is substantially flush with thedistal end722. Thepressure sensing device706 may be used in substantially the same manner as described above with respect to the systems100-500 (e.g., inserted through a channel of a needle) to gain access to portal vein and take a pressure measurement thereof.
• According to an alternate embodiment, as shown inFIGS. 19-20, apressure sensing device706′ may be substantially similar to thepressure sensing device706, comprising alongitudinal body720′ including apressure sensor712′ connected to a proximal end of thedevice706′ via aconnection cable724′ along with a workingchannel752′ extending longitudinally through thebody720′. Thepressure sensor712′, however, may be mounted within a recess726′ extending laterally through adistal portion714′ of thebody720′, similarly to thepressure sensor112 shown and described with respect toFIG. 2. Since thepressure sensor712′, in this embodiment, is distanced from adistal end722′ of thebody720′, thedistal end722′ may be blunt (as shown) or, alternatively, may include a sharp tip for piercing the portal vein. Similarly to thepressure sensing device706, thepressure sensing device706′ may be used in a manner substantially similar to the portal veins106-506, as described above with respect to the systems100-500.
• As shown inFIG. 21, asystem800 may be substantially similar to the systems (e.g.,systems200,400) described above, comprising aneedle802 and apressure sensing device806, which may be substantially similar to thepressure sensing device706.FIG. 21 showssteps1 and2 for measuring a pressure within and/or providing treatment to a portal vein in which thepressure sensing device806 is inserted. Theneedle802 may be substantially similar to theneedles202,402, including alongitudinal channel808 through which thepressure sensing device806 may be slidably received. Thepressure sensing device806 may be substantially similar to thepressure sensing device706 including a workingchannel852 extending through alongitudinally extending body820 of thepressure sensing device806 for the passage of anothertool860 such as, for example, a diagnostic and/or therapeutic tool. Apressure sensor812, however, is not fixed within or along thebody820. Rather, thepressure sensor812 is movably housed within thebody820 between a first configuration (step1), in which thepressure sensor812 is received within adistal end822 of thebody820, and a second configuration (step2), in which thepressure sensor812 is moved distally out of thedistal end822 so that thepressure sensor812, which is connected to a proximal end of the pressure sensor device via aconnection cable824, is moved laterally away from thedistal end822 as it extends distally thereoutof. Although thedistal end822 of thebody820 is shown as including a sharp tip while adistal end816 of theneedle802 is shown as being blunted, it will be understood by those of skill in the art that, as described earlier with respect tosystems200 and400, either theneedle802 or thepressure sensing device806 may include the sharp tip for piercing the wall of the portal vein to gain access thereinto.
• In the first configuration, a portion of thepressure sensor812 partially occludes a distal opening854 of the workingchannel852. In one embodiment, when it is desired to insert theadditional tool860 through the workingchannel852, a physician or other user may control the movement of thepressure sensor812 from the first configuration to the second configuration via a mechanism coupled to a handle portion of thepressure sensing device806 such as, for example, a pull wire or spring loaded mechanism connected to the connectingcable824. Alternatively, thepressure sensor812 may automatically move from the first configuration toward the second configuration (and vice versa) via a mechanical switch or sensor which extends along the workingchannel852 so that, when theadditional tool860 is moved distally through the workingchannel852, the mechanical switch or sensor is triggered to move thepressure sensor812, via a distal movement of theconnection cable824 relative to thebody820, distally beyond thedistal end822, toward the second configuration. In the second configuration, thepressure sensor812 is moved distally past thedistal end822 of thebody820 to extend laterally relative to a longitudinal axis of thepressure sensing device806. In other words, as thepressure sensor812 is moved distally past thedistal end822, theconnection cable824 bends so that thepressure sensor812 falls away from the longitudinal axis of thepressure sensing device806 to provide a clear path for theadditional tool860 to enter the portal vein. In one embodiment, theconnection cable824 may include shape memory characteristics so that, theconnection cable824 bends toward a predetermined configuration, when thepressure sensor812 is pushed out of thebody820.
• Upon removal of theadditional tool860 from the workingchannel852, thepressure sensor812 may be manually drawn back into thebody820 toward the first configuration or, alternatively, may be drawn back into thebody820 automatically via a mechanical switch or sensor that is triggered as theadditional tool860 is moved proximally through the workingchannel852.
• As shown inFIGS. 22-25, asystem900 according to another exemplary embodiment of the present disclosure may be substantially similar to thesystem800, comprising aneedle902 and apressure sensing device906. As described above, a portal vein may be pierced via one of theneedle902 and thepressure sensing device906 so that a pressure of the portal vein may be measured via asensor912 of thepressure sensing device906, which is inserted into the portal vein. Thepressure sensing device906 may be substantially similar to thepressure sensing device806, including abody920 having a workingchannel952 extending longitudinally therethrough to allow anadditional tool960 to be inserted therethrough to access the portal vein. Similarly to thepressure sensing device806, in a first configuration, thepressure sensor912 occludes a portion of adistal opening954 of the workingchannel952 so that, thepressure sensor912 must be moved toward a second configuration to permits passage of theadditional tool960 through the workingchannel952 and into the portal vein. Rather than being moved distally past a distal end922 of thebody920, however, in the second configuration, thepressure sensor912 is moved into correspondingly sized, shaped and positionedcavity956 formed along an interior surface of thebody920.
• In particular, as shown inFIGS. 22-23, thepressure sensing device906 is comprised of thelongitudinally extending body920 through which the workingchannel952 extends, substantially parallel to a central longitudinal axis of thebody920. Thepressure sensor912 is positioned at the distal end922 of thebody920 and is connected to a proximal portion of thepressure sensing device906 via aconnection cable924 extending longitudinally through thebody920. Theconnection cable924 may also extend substantially parallel to the central longitudinal axis of thebody920. Theconnection cable924 and thepressure sensor912 are in a longitudinally fixed position with respect to thebody920. However, thepressure sensor912 is laterally movable with respect to the central longitudinal axis of thebody920. Specifically, thebody920 includes acavity956 that is sized and shaped to correspond with thepressure sensor912. Thecavity956 is axially aligned with thepressure sensor912 so that, when thepressure sensor912 is moved toward the second configuration, thepressure sensor912 drops into and/or is pushed into thecavity956 to provide a clear path via which theadditional tool960 may be inserted into the portal vein via the workingchannel952.
• In one embodiment, thepressure sensor912 may include a housing or casing958 that is movably connected to theconnection cable924. Thehousing958 may be slid laterally relative to theconnection cable924 between the first configuration and the second configuration. In particular, thehousing958 may include a slot or track959, as shown inFIG. 25, within which adistal end925 of theconnection cable924 may slid to permit movement of thepressure sensor912 between the first and second configuration, as shown inFIG. 24. Thedistal end925 may include an enlarged end received within thetrack959 to prevent theconnection cable924 from being inadvertently disconnected fromhousing958.
• In an embodiment, thepressure sensor912 may be biased toward the first configuration. When theadditional tool960 is inserted distally through the workingchannel952 of thebody920, adistal end962 of theadditional tool960 may be pushed against a rounded edge of thehousing958, which pushes thepressure sensor912 into thecavity956 toward the second configuration so that theadditional tool960 may be moved distally therepast into the portal vein. Upon removal of theadditional tool960, thepressure sensor912 may revert to its biased first configuration.
• As discussed above with respect to the systems100-900, pressure sensing devices may be guided to the portal vein under EUS guidance. In some cases, the portal sensing devices described above may also include an additional sensor for enabling magnetically driven tracking and/or mapping. This feature may be particularly useful where thepressure measuring device606 is used without ultrasound, or for training purposes to spatially verify the location of the wire in the anatomy during an EUS procedure. Alternatively or in addition, a magnetically driven or fiber optic 3D shaping sensor could be added as an additional control to track the sharp tip of the pressure sensing device, needle, or stylet used to gain access to the portal vein during the procedure. Information provided to the user (e.g., physician) may be used as safety feedback to ensure that an opposite side of the vein (i.e., a far wall of the vein) is not inadvertently punctured.
• It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the scope of the disclosure.

Claims (21)

1-15. (canceled)

16. A system for measuring a pressure in a vein, comprising:

a needle sized and shaped to be inserted through a working channel of an endoscope, the needle extending longitudinally and including a channel extending longitudinally therethrough; and

a pressure sensing device including a longitudinally extending body sized and shaped to be slidably inserted through the channel of the needle and a sensor mounted on a distal portion of the body and connected to a proximal portion of the pressure sensing device via a connection cable, the sensor configured to detect information corresponding to a pressure of a flow of blood through a vein.

17. The system ofclaim 16, wherein the pressure sensing device is longitudinally movable relative to the needle between an insertion configuration, in which the sensor is covered via a portion of the needle, and a pressure sensing configuration, in which a distal end of the body of the pressure sensing device extends distally past a distal end of the needle to expose the sensor to a flow of fluid within the vein.

18. The system ofclaim 17, wherein the distal end of the needle includes a sharp tip for piercing a wall of the portal vein and the distal end of the body of the pressure sensing device includes a blunted end so that, in the insertion configuration, the distal end of the body is positioned relative to the sharp tip of the needle to prevent the sharp tip from damaging the working channel of the endoscope.

19. The system ofclaim 18, wherein the pressure sensing device is proximally movable relative to the needle so that the sharp tip is exposed to pierce a wall of the vein.

20. The system ofclaim 17, wherein the distal end of the body of the pressure sensing device includes a sharp tip and the distal end of the needle is blunted so that, in the insertion configuration, the sharp tip of the pressure sensing device is housed within the channel of the needle, and, in the pressure sensing configuration, the pressure sensing device is moved distally relative the needle, exposing the sharp tip of the body to pierce a wall of the portal vein.

21. The system ofclaim 17, wherein, in the pressure sensing configuration, the distal end of the body is moved distally past the distal end of the needle via a predetermined distance, the pressure sensing device including fins coupled to the body so that the fins are movable between a first configuration, in which the fins are constrained toward an exterior surface of the body in the insertion configuration, and a second configuration, in which the fins are moved radially outward to engage a portion of the needle in the pressure sensing configuration.

22. The system ofclaim 16, further comprising a stylet sized and shaped to be inserted through the channel of the needle, the stylet being longitudinally movable relative to the needle between an insertion configuration and a piercing configuration.

23. The system ofclaim 22, wherein a distal end of the stylet includes a sharp tip and a distal end of the needle is blunted so that, in the insertion configuration, the sharp tip of the stylet is housed within the channel of the needle and, in the piercing configuration, the sharp tip of the stylet is moved distally past the distal end of the needle.

24. The system ofclaim 22, wherein a distal end of the needle includes a sharp tip and a distal end of the stylet is blunted so that, in the insertion configuration, the distal end of the stylet is positioned relative to the distal end of the needle to prevent the sharp tip of the needle from damaging the working channel of the endoscope and, in the piercing configuration, the stylet is drawn proximally relative to the needle to expose the sharp tip of the needle for piercing a wall of the vein.

25. The system ofclaim 16, wherein the sensor is mounted within a recess extending laterally into the body of the pressure sensing device along the distal portion thereof.

26. The system ofclaim 16, wherein the body of the pressure sensing device includes a through hole extending laterally through the distal portion of the body so that a distal face of the sensor is exposed to a flow of fluid passing through the through hole.

27. A device for measuring a pressure within a vein, comprising:

a body extending longitudinally from a proximal end to a distal, the body sized and shaped to be inserted through one of a working channel of an endoscope and a channel of an endoscopic needle; and

a sensor is positioned on a distal portion of the body, the sensor connected to a proximal portion of the device via a cable connection, the sensor configured to detect information corresponding to a pressure of a flow of blood through a vein.

28. The device ofclaim 27, further comprising a working channel extending longitudinally through the body.

29. The device ofclaim 28, wherein the sensor is movably relative to the body between a first configuration, in which a portion of the sensor occludes a distal opening of the working channel extending through the body, and a second configuration, in which the sensor is moved away from a central axis of the body so that a tool inserted through the working channel of the body has a clear path for insertion into the vein.

30. The device ofclaim 27, further comprising a cauterizing needle knife slidably housed within the body for creating a hole in a wall of the vein through which the body is insertable to measure the pressure of the vein.

31. A method for measuring a pressure in a vein, comprising:

inserting a needle through a working channel of an endoscope to a target area proximate a vein; and

piercing a wall of the vein and inserting a distal portion of a pressure sensing device into the vein to measure a pressure thereof, the pressure sensing device including a sensor mounted on the distal portion and connected to a proximal portion of the device via a connection cable.

32. The method ofclaim 31, wherein the wall of the vein is pierced via one of a sharp tip of the needle, a sharp tip of a stylet slidably received within the needle, a sharp tip of the pressure sensing device, and a cauterizing needle knife of the pressure sensing device.

33. The method ofclaim 31, further comprising inserting a tool through a working channel of the pressure sensing device and into the vein.

34. The method ofclaim 32, wherein inserting the tool includes moving the sensor from a first configuration, in which a portion of the sensor occludes a distal opening of the working channel extending through the body, and a second configuration, in which the sensor is moved away from a central axis of the body so that the tool has a clear path for insertion into the vein.

35. The method ofclaim 31, wherein, in a pressure sensing configuration, a distal end of the pressure sensing device extends distally from a distal end of the needle via a predetermined distance, the pressure sensing device including fins that are movable between a first configuration, in which the fins are constrained toward an exterior surface of the pressure sensing device via an interior surface of the channel of the needle, and a second configuration, in which the fins are moved radially outward to engage a portion of the needle in the pressure sensing configuration.

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