System and method for marking body cavities

Systems and methods for marking a body cavity. In one embodiment, a system includes means for inspecting a body cavity, and means for visibly marking the body cavity so as to convey visual information regarding the body cavity. In one embodiment, a method includes inspecting a body cavity and marking the body cavity with a marking material to provide a visual indication regarding the cavity. In one embodiment, a marking material for marking a body cavity includes a radiopaque contrast agent that is viewable through fluoroscopy and a colored dye that is viewable using an internal viewing device.

BACKGROUND

Surgeons are often called upon to inspect internal body cavities to diagnose or remedy a medical condition. For example, a surgeon may inspect the calices of a patient's kidney to search for and remove kidney stones.

In the case of kidney inspection and stone removal, the surgeon may need to inspect each of multiple calices of the kidney.FIG. 1illustrates a typical kidney10that is representative of a kidney that a surgeon may need to inspect. As is shown inFIG. 1, the kidney10includes an outer capsule12that surrounds a renal cortex14in which a plurality of minor calices16are formed. Each of the minor calices16may extend from a major calyx18that, in turn, extends from the renal pelvis20. The renal pelvis20is connected to the ureteropelvic junction22, which leads down to the ureter24.

To inspect the kidney10, the surgeon will normally insert a viewing device, such as an endoscope, into each of the calices16of the kidney10to enable visual inspection of each calyx for stones. Such a viewing device may be inserted into the kidney via the urinary tract. Fluoroscopy may also be used during such a procedure to aid the surgeon in positioning the viewing device in the desired portion of the kidney10.

It is common for surgeons to use a top-to-bottom approach when inspecting the kidney10. In such a procedure, the surgeon checks a first calyx16, determines whether it contains any stones, and, assuming it does not, checks the next calyx. When a stone is discovered, it is fragmented, if necessary, and removed from the calyx16using a retrieval device. This process continues from the top26of the kidney10to the bottom28of the kidney until each calyx16has been inspected and every stone or stone fragment has been removed. During the process, the surgeon or the surgical staff tracks which calices16have been inspected in an effort to ensure that each calyx is checked.

Because there may be many different calices16to inspect and because the position of the viewing device can only be inferentially determined from the images captured by the viewing device and any captured fluoroscopic images, it is often difficult for the surgeon to know with any certainty whether a given calyx has or has not been inspected. As a result, the surgeon may revisit one or more calices one or more times to ensure that it has been checked and does not contain any stones. This “double-checking” lengthens the time required to complete the procedure, thereby increasing risk and/or discomfort to the patient.

Even in cases in which the surgeon and staff are careful in keeping track of which calices16have been inspected, it is possible for them to make a mistake that results in one or more calices not being inspected. In such a case, one or more stones or stone fragments may remain which can act as seeds for further stone formation.

In cases in which a stone must be fractured before being removed, for instance if the stone is too large to be removed as a single piece, lithotripsy may be performed to break the stone into smaller fragments. When lithotripsy is performed, it is possible for a stone fragment to be propelled into a calyx16that has already been checked. If this happens, one or more stones or stone fragments may remain which, again, can act as seeds for further stone formation.

SUMMARY

Disclosed are systems and methods for marking a body cavity. In one embodiment, a system includes means for inspecting a body cavity, and means for visibly marking the body cavity so as to convey visual information regarding the body cavity.

In one embodiment, a method includes inspecting a body cavity, and marking the body cavity with a marking material to provide a visual indication regarding the cavity.

In one embodiment, a marking material for marking a body cavity includes a radiopaque contrast agent that is viewable through fluoroscopy, and a colored dye that is viewable using an internal viewing device.

DETAILED DESCRIPTION

As is described in the foregoing, it can be difficult to keep track of which of multiple body cavities have or have not been inspected during a surgical procedure. As is discussed in the following, however, the progress of such inspection can be clearly indicated using a marking material. By way of example, such a marking material can be used to mark one or more cavities that have already been inspected. Alternatively, a marking material can be used to mark one or more cavities of interest, for example that contain an object to be removed. In a further alternative, a first type of marking material can be used to mark cavities of a first type (e.g., that contain objects to be removed) and a second type of marking material can be used to mark cavities of a second type (e.g., that contain no objects to be removed). The marking material contains a marking substance that can be viewed with a viewing device and/or that can be viewed fluoroscopically. In the former case, the marking substance may comprise a dye. In the latter case, the marking substance may comprise a contrast agent.

Referring now to the drawings, in which like reference numerals identify corresponding components,FIGS. 2A-Eillustrate various steps in an embodiment of a method for inspecting a plurality of internal body cavities. In the example ofFIGS. 2A-2E, the body cavities comprise calices of a kidney that are to be inspected for kidney stones. Although a kidney application is shown in the figures and is described in detail herein for purposes of example, the systems and methods of this disclosure can be applied to other internal body cavities. Therefore, the present disclosure is intended to cover applications beyond kidney inspection and stone removal.

Beginning withFIG. 2A, illustrated is the kidney10first described in relation toFIG. 1. As is described above, the kidney10comprises a plurality of calices16that may comprise kidney stones that are to be removed (none visible in the view ofFIG. 2A). While the bodies of some of the calices16are visible inFIG. 2A, only the openings of other calices are visible (indicated by circles inFIGS. 2A-2E).

As is illustrated inFIG. 2A, an internal viewing device30has been inserted into the kidney10via the ureter24. By way of example, the viewing device30comprises a ureteroscope that has been inserted through a ureteral access sheath32that has been inserted into the urinary tract via the external meatus. Although use of an access sheath32is depicted inFIG. 2A, the viewing device30could, alternatively, be inserted through the urinary tract without the access sheath. Use of the access sheath32, however, simplifies insertion and removal of the viewing device30, particularly in cases in which the viewing device must be repeatedly inserted and removed, as when removing multiple stone fragments. In alternative embodiments, the viewing device30can be introduced into the kidney10using other methods, for instance percutaneously.

With further reference toFIG. 2A, the viewing device30has been maneuvered into a first calyx34of the upper portion of the kidney10. That calyx34may, for example, be a suitable calyx to start with in a top-to-bottom inspection procedure, such as that described in the foregoing. As is shown inFIG. 2A, the calyx34is clear of any stones or other objects that would require removal. Because of this, no further action is required in relation to the calyx34, and the surgeon may move on to the next calyx16of the kidney10.

As is described above, it can be difficult for a surgeon or the surgical staff to keep track of which calices16have or have not been inspected. To avoid this problem, the surgeon can mark the calyx34prior to moving on to the next calyx16. By marking the calyx34in this manner, the surgeon can readily determine that he or she has already inspected that calyx and understand that no further inspection of the calyx is necessary. In some embodiments, marking can be achieved by filling the calyx34with a marking material. Such a procedure is illustrated inFIG. 2B. As is indicated in that figure, the calyx34has been filled with a marking material36. Although the entire calyx16is shown filled with that marking material36, the calyx (or other cavity) could be marked by filling only a portion of the calyx with the marking material. For example, the marking material36could be used to fill just the entrance to the calyx34, if desired.

The marking material36can be deposited using various different devices and techniques. In some embodiments, the marking material36is injected into the calyx34(or other cavity) using a working or irrigation channel of the viewing device30. In other embodiments, the marking material36is delivered using a separate catheter that is inserted through the urinary tract (not shown). In still further embodiments, the marking material36is percutaneously injected into the desired site using an external injection device, such as a syringe.

Irrespective of the manner in which the marking material36is deposited, the marking material contains a marking substance that is visible using one or both of the viewing device and fluoroscopy. In some embodiments, the marking material36comprises one or more dyes that enable the surgeon to readily identify the marking material when viewing the kidney interior using the viewing device30. Suitable dyes include, for example, methylene dyes, such as methylene blue and methylene red. When such a dye is used, the surgeon will be able to readily determine that the calyx34has already been inspected upon later returning to that area of the kidney10.

In some embodiments, the marking material36further or alternatively includes a contrast agent that enables identification of the marking material, and the cavity in which it is placed, through fluoroscopy. The term “contrast agent” refers to any radiopaque material capable of being fluoroscopically monitored. The contrast agent can be either water soluble or water insoluble. Examples of water soluble contrast agents include metrizamide, iopamidol, iothalamate sodium, iodomide sodium, and meglumine. Examples of water insoluble contrast agents include tantalum, tantalum oxide and barium sulfate, each of which is commercially available in the proper form for in vivo use. Other water insoluble contrast agents include gold, tungsten and platinum. As with the dye, the contrast agent assists the surgeon in determining which calices16(or other cavities) have already been inspected.

In some preferred embodiments, the marking material36is in liquid form prior to deposition, but forms a gel after or during deposition. In some embodiments, the marking material36can be a temperature-sensitive material that is in liquid form below normal body temperature, but that forms a gel at or above body temperature. Such materials include lower critical solution temperature materials, such as polyoxyethylene-polyoxypropylene (PEO-PPO) block copolymers. When such a material is used, it can be delivered to the calyx34in liquid form, and then transition into a gel as it is heated by the kidney10. Alternative temperature-sensitive materials include those that are in liquid form at or above normal body temperature, but form a gel below body temperature. In such a case, the material can be deposited within the calyx34and cooled to form a gel. Examples of such materials include gelatin materials.

In other embodiments, the marking material36comprises two separate component that, when mixed, form a gel. One example of such materials are those that include crosslinkable polymers that form a gel when contacted with a crosslinking agent. Crosslinkable polymers that may be suitable for use in the invention include both ionically crosslinkable and non-ionically crosslinkable polymers. Crosslinking agents that may be employed include both ionic crosslinking agents and non-ionic crosslinking agents. Ionically crosslinkable polymers include anionic crosslinkable polymers and cationic crosslinkable polymers that may be used in conjunction with anionic crosslinking agents and cationic crosslinking agents, respectively.

Irrespective of the type of marking material36that is used, the marking material is a temporary implant that it is automatically or manually removed once it is no longer needed to identify the calyx34(or other cavity). For example, in cases in which the marking material36is a temperature-sensitive material, the material will slowly degrade within the kidney and be excreted. Optionally, the speed with which the temperature-sensitive gel breaks down can be increased by either cooling or heating the marking material36, depending upon whether the material forms a gel at higher or lower temperatures.

In cases in which the marking material36comprises two separate components that together form a gel, breakdown of the marking material can, for example, be achieved by providing a third material that degrades the gel. For instance, if the marking material36includes a crosslinkable polymer, a suitable de-crosslinking agent may be used to dissolve the gel, in which case the material will again be excreted. Suitable de-crosslinking agents include sodium phosphate, sodium citrate, inorganic sulfates, ethylene diamine tetraacetic acid and ethylene dime tetraacetate, citrates, organic phosphates (e.g., cellulose phosphate), inorganic phosphates (e.g., pentasodium tripolyphosphate, mono- and di-basic potassium phosphate, sodium pyrophosphate), phosphoric acid, trisodium carboxymethyloxy succinate, nitrilotriacetic acid, maleic acid, oxalate, polyacrylic acid, sodium, potassium, calcium, or magnesium ions.

In still other embodiments, the gel may be removed by drawing the gel out of the calyx using a lumen of the viewing device or a separate catheter.

Although the marking material36may, in some cases, naturally degrade and be excreted over time, the marking material will remain in place for at least the duration of the inspection procedure. Therefore, as the surgeon moves on to other calices16(or other cavities), the marking material36will continue to provide a visual marker of where the surgeon has already been.

Referring now toFIG. 2C, the surgeon has manipulated the viewing device30such that it is positioned for insertion into a second calyx38(which extends into the page inFIG. 2C). Assuming that the second calyx38comprises a stone (not visible inFIG. 2C), the surgeon can identify the stone using the viewing device30, and then remove it. Referring toFIG. 2D, the surgeon has removed the stone40using a retrieval device42. By way of example, the retrieval device42is inserted through a working channel of the viewing device30. In such a case, the retrieval device42and the viewing device30can be withdrawn from the body together (e.g., via the access sheath32) to remove the stone40. Alternatively, the retrieval device42can be inserted into the kidney10separate from the viewing device30.

After the stone40has been removed, and assuming no other stones exist in the second calyx38, the calyx can be marked with the marking material36in similar manner to that described above in relation to the first calyx34. Accordingly, the second calyx38can, for example, be filled with the marking material36as is indicated inFIG. 2E. Again, such filling can be accomplished using a working or irrigation channel of the viewing device30, a separate catheter, or a percutaneous injection device.

The above-described process can continue in similar manner until every calyx16has been inspected, all stones have been removed, and all inspected calices have been marked. In such a case, the surgeon can readily determine that each calyx has been inspected. In cases in which the marking material36comprises a gel, a further benefit is provided if lithotripsy is performed. Specifically, once a calyx16, or its entrance, has been filled with a gel-based marking material, fragments that break off of a stone during lithotripsy will not be able to enter the calyx. Therefore, the surgeon need not recheck previously-inspected calices after lithotripsy.

FIGS. 3A and 3Billustrate an example of a further marking application. Beginning withFIG. 3A, a given calyx44comprises a plurality of stones46that are to be removed. By way of example, the stones46comprise fragments of a larger stone that was broken up through lithotripsy. Assuming that the surgeon can only remove one stone46at a time, or at least cannot remove all of the stones at once, the surgeon may need to return to the calyx44one or more times after withdrawing the viewing device30. In such a case, it may be difficult for the surgeon to relocate the calyx44or distinguish it from other calices16of the kidney10. To aid the surgeon in such relocation, the surgeon can mark the calyx44with the marking material36, as is indicated inFIG. 3A. After marking the calyx44, the surgeon can then remove the stones46(e.g., one by one) from the calyx through the marking material36using the retrieval device42. In cases in which the marking material36is a gel, the marking material will stay in place despite the insertion and withdrawal of the viewing device30and/or retrieval device42.

FIG. 4illustrates a further marking application. In this application, several of the calices48have been marked with a first marking material50to indicate a first condition, and one calyx52has been marked with a second marking material54to indicated a second condition. In this example, the first condition is absence of any stones and the second condition is presence of one or more stones56. The marking material50is distinguishable from the marking material54in one or more ways. In some embodiments, the marking material50comprises a different colored dye than the marking material54comprises. In such a case, the surgeon can distinguish the two types of calices (e.g., those containing stones and those not containing stones) using the viewing device30. In addition or exception, the marking material50comprises a different concentration of contrast agent than the marking material54. In such a case, the surgeon can distinguish the two types of calices from a fluoroscopic image.

As is indicated inFIG. 4, each of the calices48extends from a major calyx58. In such a case, in which the cavities to be marked comprise all of the cavities of a given group or branch of cavities, the entire calyx58can be filled with the marking material50to indicate that that entire portion of the kidney10has already been inspected.