Abstract: A fibrous tissue repair device includes first and second tubular anchors having corresponding longitudinal passages. The tissue repair device includes corresponding first and second inserters. Each inserter has a shaft with a distal portion received in the longitudinal passage of the corresponding tubular anchor. A flexible strand couples the first and second anchors.

Abstract: Devices and methods for anchoring surgical sutures are provided. In general, a device as described includes an anchor assembly formed of a plurality of rigid anchor segments including a proximal segment and a distal anchor segment comprising a force transferring element, and at least one segment having at least one interdigitation element configured to create an engagement force between the at least one segment and a tissue. The device further includes a flexible member linking the plurality of anchor segments and configured to transition the anchor from a first, flexible configuration when the flexible member is in a relaxed state to a second, substantially rigid configuration when the flexible member is in a taut state.

Abstract: A fixation device includes a member defining at least two openings, and a suture tied to the member by passing the suture through the at least two openings in the member to form two suture loops through which ends of the suture pass. The two suture loops are interconnected. A method of securing a tissue graft includes providing the fixation member, attaching the suture to a tissue graft, and adjusting the length of the suture between the fixation member and the tissue graft by pulling the suture.

Abstract: In laparoscopic surgery, tying of knots is not easy, as it involves the use of long handled graspers and the necessity to pass one end of the suture ligature around the opposite half of the suture, with release and re-grab of the passing end of the suture. The present invention avoids the “passing with the release and re-grab”, and makes the tying easier, faster and automatic. It conforms to the general size and shape of a standard laparoscopic instrument. The handle is pistol shaped with two control triggers, one for grasping and the other for rotating. The sheath is elongated and tubular, containing two control rods. The tip is bullet shaped, containing three operating mechanisms, one for grasping the leading end of a suture, a second for trapping the opposite half of the same suture, a third for rotating the grasped end of the suture 360 degrees around the trapped portion, thus forming a knot. The trapping mechanism uses an axle with a hollow center and an open-ended side slot.

Abstract: An apparatus comprises a shaft and an end effector. The end effector is positioned at the distal end of the shaft and is operable to form a fastener assembly to secure tissue. The end effector includes first and second fastener assembly forming features. The first fastener assembly forming feature is rotatable relative to the shaft. The fastener assembly is formed by first and second fastener assembly members. The first fastener assembly member comprises a buttress strip received by the first fastener assembly forming feature. The second fastener assembly member comprises either a wire with protruding portions or a fastener strip with integral protruding fasteners. The buttress strip receives the protruding portions or protruding fasteners to secure tissue between the buttress strip and the wire or fastener strip. The end effector may transect layers of tissue and fasten the layers of tissue together on each side of the transection.

Abstract: The present invention disclosed a surgical staple (50) and staple pocket (57) for forming kidney-shaped staple therefor, with the staple pocket (57) being recessed inward on the tissue contacting surface of the staple anvil (58), and with M-shaped staple (50) being used, wherein the degree of projection of the middle portion of the back span (51) of the M-shaped staple (50) arranged at the inner circle or arranged at a proximal side of a cutter slot (121) is larger than that of the back span (51) of the M-shaped staple (50) arranged at the outer circle or arranged at a distal side of the cutter slot (121), so that when the staple (50) of the same height are adapted to staple tissues to be stapled of different thickness, staple driver (68) bends the M-shaped staple (50) on the staple pocket (57) to form kidney-shaped staple (50) so as to achieve the operational effect of being able to seal the stapled tissue, to stop bleeding and to heal the tissue therearound.

Abstract: Surgical instruments are disclosed that are couplable to or have an end effector or a disposable loading unit with an end effector, and at least one micro-electromechanical system (MEMS) device operatively connected to the surgical instrument for at least one of sensing a condition, measuring a parameter and controlling the condition and/or parameter.

Abstract: In various embodiments, a surgical staple cartridge is provided. The staple cartridge comprises a cartridge housing, a knife, a first row of staple pockets, a second row of staple pockets, and a third row of staple pockets. The staple cartridge further comprises a plurality of first staples, a plurality of second staples, and a plurality of third staples. The staple cartridge further comprises, one, a first staple driver oriented to drive a first staple out of the staple pockets in the first row, a second staple out of the staple pockets in the second row, and a third staple out of the staple pockets in the third row and, two, a second staple driver oriented to drive a total of four staples out of the staple pockets in the first row, the second row and the third row of staple pockets.

Abstract: An apparatus for treating obesity comprising a volume filling device assembled from at least two segments and is provided and following implantation, the device is placed resting against the stomach wall of the patient to reduce the inner volume of the stomach, thereby affecting the patient's appetite.

Abstract: An apparatus for closing a surgical incision comprises left and right base panels, a plurality of closure components, and a plurality of left and right axial supports coupled to the respective base panels. The closure components couple the left and right base panels to each other laterally and have left and right ends coupled to the respective base panels. The closure components are positioned laterally across the left and right panels, the left axial supports are disposed between pairs of left closure component ends, the right axial supports are disposed between pairs of right closure component ends, and the left and right axial supports are offset from one another such that a serpentine arrangement of consecutive closure components and axial supports is formed. The apparatus can be made of antimicrobial materials or materials impregnated with antimicrobial agents. A flexible adhesive cover can be provided over the apparatus when in use.

Abstract: Systems and methods for treating an afflicted vessel and/or vessel associated with an afflicted tissue of a mammalian patient are presented herein. In particular, devices for the control of flow rate and/or pressure within a vessel of a mammalian patient, and methods of treating an afflicted vessel and/or a vessel associated with an afflicted tissue using the devices are presented herein.

Abstract: A device and method for treating an aneurysm include a catheter capable of insertion into a body to be positioned adjacent the aneurysm, the catheter including a distal end and an operator end opposite the distal end. The catheter forms a circular pathway extending between the distal end and the operator end. A partitioner extends through the pathway of the catheter, the partitioner being rotatable within the catheter and including one or more lumens that provide an orifice from a first end of the partitioner to a second end of the partitioner. The device further includes a first coil extending through the partitioner from the first end to the second end in a first lumen and a second coil extending through the partitioner from the first end to the second end in a second lumen. The first and second lumens may be fully circumscribed by the partitioner and have first and second diameters, respectively.

Abstract: Space-occupying devices for treating voids within the body are disclosed. The devices can have multiple elements connected to a flexible leader. The devices can be coated by a binding agent. The devices can also be fillable. Methods of making and using the devices are also disclosed.

Abstract: A surgical device for clipping tissue can include an actuator, such as a handle or a robotic arm, for example, and a replaceable end effector including a plurality of clips contained therein. After the replaceable end effector has been used, the end effector can be detached from the actuator and a new end effector can be operably coupled with the actuator. Each replaceable end effector can include a firing drive for advancing clips into a receiver of the end effector and a crimping drive configured to deform a clip positioned within the receiver.

Abstract: Customized patient-specific orthopedic surgical instruments are disclosed. Methods for fabricating and using such instruments are also disclosed.

Abstract: A system for reaming a bone including a guiding wire configured to be attached to the bone; a tubular depth guide configured to cover at least a portion of the guiding wire, the tubular depth guide including a first end configured to abut the bone, and a second end opposite the first end; a reaming device including an elongate recess therein that extends between a reaming tool of the reaming device and an interior of a handle of the reaming device, wherein the elongate recess is configured to receive each of the guiding wire and depth guide therein, the elongate recess includes a reduced diameter section that defines a shoulder, and the shoulder is designed to abut the second end of the tubular depth guide to control a depth to which the bone is reamed.

Abstract: An alignment guide for aligning instrumentation along a proximal femur includes a neck portion configured to wrap around a portion of the neck of the femur, a head underside portion configured to abut a disto-lateral portion of the femoral head and a medial head portion configured to overlie a medial portion of the head. Portions of the guide can have an inner surface generally a negative of the femoral bone of a specific patient that the guide overlies; such surfaces can be formed using data obtained from the specific patient. The neck portion can be configured to rotationally stabilize the guide by abutting and generating a first gripping force on the neck. The femoral head portions can be configured to grip the head portion of the femur and can support a bore guide that is configured to guide an instrument to the femur in a specified location and along a given axis.

Abstract: The invention provides for microneedle devices for delivering agents across biological barriers. The microneedles include agent reservoirs integrated into the bodies of the microneedles, themselves.

Abstract: A cardiac ablation device, including a steerable catheter (10) and an expandable ablation element (18) incorporating one or more balloons (20,22) at the distal end of the catheter, has a continuous passageway (28, 30) extending through it from the proximal end of the catheter to the distal side of the expandable ablation element. A probe (72) carrying electrodes is introduced through this passageway and deploys, under the influence of its own resilience, to a structure incorporating a loop (82) which is automatically aligned with the axis of the expandable ablation device, so that minimal manipulation is required to place the sensor probe.

Abstract: Methods and devices described herein facilitate diaphragm entry for posterior access of body organs.

Abstract: The invention provides surgical or diagnostic tools and associated methods that offer improved user control for operating remotely within regions of the body. These tools include a proximally-located actuator for the operation of a distal end effector, as well as proximally-located actuators for articulational and rotational movements of the end effector. Control mechanisms and methods refine operator control of end effector actuation and of these articulational and rotational movements. A rotation lock provides for enablement and disablement of rotatability of the end effector. The tool may also include other features. A multi-state ratchet for end effector actuation provides enablement-disablement options with tactile feedback. A force limiter mechanism protects the end effector and manipulated objects from the harm of potentially excessive force applied by the operator.

Abstract: The teachings herein provide an instrument comprising a forceps. The forceps comprise a hand piece; a tubular member connected to the hand piece; and a jaw assembly connected to the hand piece. The jaw assembly includes a first jaw element and a second jaw element. The first jaw element includes a gripping section and a flexing section. The flexing section includes an arcuate section. The second jaw element opposes the first jaw element and includes a gripping section. The tubular member is moveable onto the arcuate section of the first jaw element so that the flexing section of the first jaw element is flexed and the jaw assembly is moved into a closed position. The first jaw element, the second jaw element, or both include a stiffening spine so that the jaw assembly is substantially rigid in the closed position.

Abstract: A surgical hand grip for a surgical tubular shaft instrument is provided. The hand grip includes a coupling device for coupling to a tubular shaft tool having a tubular shaft and a force transmission element movable back and forth relative thereto. The coupling device has a coupling element for coupling to the force transmission element and a connecting element for connecting to the tubular shaft. A gripping device is connected to the coupling element and is transferable from a non-actuating disposition into at least one actuating disposition and vice versa thereby changing the mutual relative spacing between the coupling element and the connecting element. The hand grip has a guiding device with a guiding body for guiding the coupling element during the transfer from the non-actuating position into the at least one actuating position along a grip axis independently of the disposition of the gripping device during the transfer.

Abstract: A medical device for tissue resection and related methods of use are disclosed. The device may include an elongate member having a proximal end and a distal end. The distal end of the elongate member may include a distal portion defining an end face and a cavity extending distally therefrom. The distal portion may further include multiple sections configured to transition between a first position and a second position different from the first position. The medical device may further include a mechanism configured to adjust a volume of the cavity by moving at least one of the multiple sections from the first position to the second position.

Abstract: A fluid ejection device includes a fluid accommodation portion having an outlet and a fluid pressing unit that causes the fluid to flow out of the fluid outlet through a channel. A fluid ejection unit ejects in a pulsed manner the fluid received from a fluid intake port connected to the channel. A pressure detection unit detects an inner pressure of the fluid accommodation portion. A press control unit controls the inner pressure of the fluid accommodation portion to approach a target pressure value when the channel is closed. A channel determination unit determines that the channel is not closed if a detected movement speed of the fluid pressing unit is a predetermined speed or greater when a predetermined amount of time has elapsed after a difference between the inner pressure of the fluid accommodation portion and the target pressure value becomes less than a predetermined value.

Abstract: A fluid ejection device includes a fluid ejection unit that ejects a fluid, an ejection control unit that receives a fluid ejection command input, and controls the ejection of the fluid from the fluid ejection unit, a fluid container that accommodates the fluid to be supplied to the fluid ejection unit; and a supply control unit that controls the supply of the fluid from the fluid container to the fluid ejection unit, and determines whether the fluid can be supplied to the fluid ejection unit from the fluid container. When the supply control unit determines that the fluid cannot be supplied even after the ejection command input is received, and then a predetermined amount of time has elapsed, the ejection control unit reports a fault, and prohibits the fluid ejection unit from ejecting the fluid until the ejection command input is canceled.

Abstract: Exemplary embodiments of method and apparatus are provided for resurfacing of skin that includes formation of a plurality of small holes, e.g., having widths less than about 1 mm or 0.5 mm. For example, such small holes can be produced using a mechanical apparatus that includes one or more abrading elements provided at the end of one or more rotating shafts, thus avoiding generation of thermal damage as occurs with conventional laser resurfacing procedures and devices. The holes thus formed can be well-tolerated by the skin, and may exhibit shorter healing times and less swelling than conventional resurfacing procedures. The fractional surface coverage of the holes can be between about 0.1 and 0.7, or between about 0.2 and 0.5. The method and apparatus can produce cosmetic improvements in the skin appearance by eliciting a healing response.

Abstract: A disposable circumcision apparatus, comprising, a fixture device comprising a surrounding wall, the surrounding wall comprising an opening, a blade formed along an interior surface of the surrounding wall, the blade comprising a first blade mating portion and a second blade mating portion that mate with each other when the fixture device is in a closed position, the blade further comprising a blade interior circumferential edge, a cushion ring for being positioned against the blade further comprising a groove formed along a blade interior circumferential edge, means for maintaining the fixture device in a closed position, and a balanus ferrule for placement within the cushion ring and fixture device.

Abstract: The disclosure is directed to an implant tool used to facilitate the implantation of a medical device into a patient. The implant tool includes a housing that is held by a user and a needle attached to the housing. The needle is configured so that a cannula may be positioned over the needle and delivered to the target tissue. The implant tool also includes a release mechanism that pushes the cannula off of the needle. The release mechanism may help the user to keep the cannula at the desired location while removing the needle from the cannula. The implant tool may also include a flange that extends from the housing adjacent to a side of the needle such that the user may provide force against the needle during advancement of the needle into the patient.

Abstract: Orthopedic fixation devices, assemblies, and methods. The orthopedic fixation devices may comprise coupling elements, hook components, and/or bone fasteners. The bone fastener may be loaded into the coupling element through the bottom of a bore in the coupling element. The orthopedic fixation devices may include modular locking clamp assemblies that can be fixed onto fasteners that are already implanted in bone. The modular locking clamp assemblies can include polyaxial locking clamp assemblies, as well as monoaxial locking clamp assemblies. The hook components may include a female hook component slidably coupled to a male hook component.

Abstract: A spinal stabilization system having a pedicle screw which includes (i) a shaft with external threads and a head segment on one end of the shaft; (ii) a first drive socket positioned in the head segment; (iii) a second drive socket on a shaft end opposite the first drive socket; and (iv) wherein the shaft end opposite the first drive socket has a lesser diameter than the shaft end at the head segment. The system further includes an intervertebral stabilization structure having an elongated body with rotating ring segments attached to each end of the elongated body.

Abstract: An osseous anchorage implant comprising an attachment structure adapted to receive and be attached to at least one bar, that is suitably an element of an osteosynthesis. The implant is made up of an osseous anchor and an attachment head bearing the attachment means. The attachment head is suitably traversed by a channel that is adapted to receive the bar. The attachment head comprises a clamp that is adapted to clamp the bar against an inside support wall of the channel. The implant is further characterized by the attachment means and the support wall enabling the rotation of the bar about a first axis that is not parallel to the longitudinal axis of the bar. The clamp comprises a moving clamping face, that is adapted to contact the bar, and that is borne by a support head that is articulatable at the end of the clamp via a ball and socket connection. The channel is suitably an open channel having an aperture opening onto one of the lateral faces of the attachment head, wherein the aperture bears the clamp.

Abstract: A transverse connector system having a first and a second locking element. The present invention also provides transverse rod having opposing first and second ends, the first end being retained within a portion of the first locking element and the second end being retained within a portion of the second locking element. The first locking element is configured with a connector body for engaging and capturing an elongated rod and a transverse rod simultaneously.

Abstract: An inventive iliac connector comprises a connector head (1) and a connecting rod (2) for connecting a sacrum (S) or a spine (SP) to an ilium (I). The connector head (1) has a first hole (15) for holding a spinal rod (3) and a second hole (16) for holding the connecting rod (2), wherein the connecting rod (2) is made of a material being more flexible than titanium. This iliac connector enables a stabilization of ilium, sacrum and spine and enables at the same time movement between ilium and sacrum.

Abstract: Minimally invasive facet release is performed during spine surgery. The minimally invasive facet release may be performed at a single level or over multiple levels. The minimally invasive facet release may be performed through a working corridor instrument which may be a tissue retractor or an access tube. When coupled with a minimally invasive pedicle screw fixation system, the facet release methods described enable a surgeon to correct a wide array of spinal deformities in a purely minimally invasive fashion.

Abstract: The present invention provides spinous process implants and associated methods. In one aspect of the invention, the implant includes at least one extension with a superior lobe pivotally connected to an inferior lobe, such as by a hinge, to allow unfolding of the at least one extension from a folded position to an unfolded position. In certain aspects, the folding extension may include fasteners to facilitate engagement with the spinous processes to provide both a flexion stop as well as an extension stop. The fasteners may have corresponding bores to allow the fasteners to reside in the bores to provide a compact profile for implantation. In another aspect of the invention, the implant is introduced to the surgical site using a lateral or paramedian approach and associated tools to facilitate the same.

Abstract: Various interspinous process spacing devices and associated methods are provided for treating spinal disease. In one embodiment, an interspinous process spacing device includes a first attachment side and a second attachment side, each attachment side including one or more slots formed therein and positioned proximate one end for receiving fasteners extending inwardly from a second interspinous process spacing device. The device further includes a spacer tray extending from the first attachment side and slideably insertable through a spacer tray slot formed in the second attachment side, wherein the spacer tray is adapted to retain adjacent spinous processes in a spaced apart orientation, and wherein at least a portion of the spacer tray has a longitudinally arcuate shape adapted to facilitate angled insertion of the spacer tray through the spacer tray slot. The device further includes securing means for securing the second attachment side relative to the first attachment side.

Abstract: A system for reducing deformities in the spine includes a first tower assembly and a second tower assembly. The first tower assembly includes a first tower that couples to a first screw in a first vertebral level, a load transfer ring rotatable coupled to the first tower, and a load transfer link rotatably coupled to the load transfer ring. The second tower assembly includes a second tower that couples to a second screw in a second vertebral level, a load applicator secured to the second tower, and a load transfer member rotatably coupled to the second tower and linked to the load transfer link. The load applicator applies force to the load transfer member to position the first tower assembly relative to the second tower assembly.

Abstract: A joint between two bone segments is fused by passing an elongated, rectilinear bone fusion device over a guide pin across the joint and into tight engagement within bores formed in the bone segments, to thereby restrict movement of the elongated bone fusion device across the joint. The elongated, rectilinear bone fusion device also provides bony in-growth within the bores along the exterior surface of the bone fusion device.

Abstract: A bone plate system for securing a plurality of bones is provided including a plate member, a locking device of the bone plate, and a surgical cable having a trailing end for being connected to the bone plate and a leading end for being advanced around the bones and into the locking device. The surgical cable may be tensioned to approximate the bones, urge the bones together, and seat the bone plate against the bones. The locking device may be reconfigured to a locked configuration to fix the bone plate to the surgical cable. The bone plate further includes a plurality of throughbores for receiving bone anchors that rigidly fix the bone plate to the bones. The bone plate system utilizes the tensile strength of the surgical cable and the rigid fixation between the bone anchors and the bone plate to resist relative movement of the bones.

Abstract: A surgical instrument kit comprising: (a) a robotic arm comprising a first jaw including a first bipolar electrode and a second jaw including a second bipolar electrode, wherein at least one of first jaw and second jaw is repositionable with respect to the other jaw; (b) a first surgical tool head including a first electrical load in electrical communication with a first pair of electrical terminals, the first surgical tool head adapted to be removably coupled to the robotic arm; and, (c) a second surgical tool head including a second electrical load in electrical communication with a second pair of electrical terminals, the second surgical tool head adapted to be removably coupled to the robotic arm, where the first pair of electrical terminals of the first surgical tool head are adapted to engage the first bipolar electrode and the second bipolar electrode to establish electrical communication between the first bipolar electrode and a first of the first pair of electrical terminals and between the second bi

Abstract: The present application discloses devices that ablate human tissue. The device comprises a catheter with a shaft through which an ablative agent can travel, a liquid reservoir and a heating component, which may comprise a length of coiled tubing contained within a heating element, wherein activation of said heating element causes said coiled tubing to increase from a first temperature to a second temperature and wherein the increase causes a conversion of liquid within the coiled tubing to vapor, a reusable cord connecting the outlet of the reservoir to the inlet of the heating component, and a single use cord connecting a pressure-resistant inlet port of a vapor based ablation device to the outlet of the heating component.

Abstract: Methods of ablating endometrial tissue are disclosed. The methods include providing an ablation device that has a catheter with a hollow shaft through which an ablative agent can travel, a first positioning element, and a second positioning element positioned on the catheter distal to the first positioning element. The second positioning element is a disc shaped wire mesh and has a diameter in a range of 0.1 mm to 10 cm.

Abstract: Ablation catheters and systems include multiple inline chambers for containing and heating an ablative agent. The heating chamber includes one or more channels to increase the contact surface area of the ablative agent with the walls of the heating chamber to provide more efficient heating. Induction heating is used to heat a chamber and vaporize a fluid within by wrapping a coil about a ferromagnetic chamber and providing an alternating current to the coil. A magnetic field is created in the area surrounding the chamber which induces electric current flow in the chamber, heating the chamber and vaporizing the fluid inside. Positioning elements help maintain the device in the proper position with respect to the target tissue and also prevent the passage of ablative agent to normal tissues.

Abstract: An electrosurgical wand. At least some of the illustrative embodiments are electrosurgical wands including an elongate housing that defines a handle end and a distal end, a first discharge aperture on the distal end of the elongate housing, a first active electrode of conductive material disposed on the distal end of the elongate housing, a first return electrode of conductive material disposed within the first fluid conduit, and an aspiration aperture on the distal end of the elongate housing fluidly coupled to a second fluid conduit.

Abstract: Multi-electrode ablation systems, methods, and controllers are described. In one example, a multi-electrode ablation system generally includes a power supply and a controller. The power supply is configured to be coupled to a plurality of electrodes for delivering power to the electrodes. The controller is operable to compare a measured temperature at each electrode to a desired temperature to thereby define a temperature difference for each electrode. The controller is operable to determine, based on the temperature difference, a desired power for each electrode, compare the desired power of one of the electrodes to an actual power delivered to the one of the electrodes to define a power difference, and adjust the actual power delivered by the power supply to the one of the electrodes based on the power difference.

Abstract: Disclosed are an electrode for high-frequency surgery, a high-frequency surgery device, and a method for controlling same, wherein the electrode for high-frequency surgery can be easily inserted and moved inside the lumens inside the body, and can expand a conduction area of a high-frequency current after reaching an area to be treated. The electrode for the high-frequency surgery, according to the present invention, comprises: a balloon; and a conductive structure, which is arranged on the outside of the balloon and the exterior shape of which varies according to the volume of the balloon.

Abstract: A device for delivering a composition to a hollow body region is disclosed. In one aspect, the device comprises a first longitudinal member and a second longitudinal member. Both of the longitudinal members may comprise conductive electrodes. The longitudinal members are further configured to be connected to an energy source such that the conductive electrodes are configured to generate an energy field. At least one of the longitudinal members further comprises a delivery element configured to deliver at least one composition to the body region, such that the composition is delivered in a direction that is influenced by the generated energy field. In one aspect, the body region is a vessel comprising an occlusion.

Abstract: A catheter is adapted to ablate tissue and provide lesion qualitative information on a real time basis, having an ablation tip section with a generally omni-directional light diffusion chamber with one openings to allow light energy in the chamber to radiate the tissue and return to the chamber. The chamber is irrigated at a positive pressure differential to continuously flush the opening with fluid. The light energy returning to the chamber from the tissue conveys a tissue parameter, including without limitation, lesion formation, depth of penetration of lesion, cross-sectional area of lesion, formation of char during ablation, recognition of char during ablation, recognition of char from non-charred tissue, formation of coagulum around the ablation site, differentiation of coagulated from non-coagulated blood, differentiation of ablated from healthy tissue, tissue proximity, and recognition of steam formation in the tissue for prevention of steam pop.

Abstract: An irrigated catheter with uniform cooling and/or uniform fluid distribution in longitudinally spaced apart elution holes by varying the diameter of a fluid delivery lumen. A number of elution holes are provided in a tip region of a catheter body, and these elution holes are in fluid communication with the lumen through ducts. The fluid delivery lumen may be provided with a flow constrictor to restrict flow of fluid towards the distal region.