Patent Application
20230210574
The inventions described below relate to the field of visceral fat reduction.
Visceral fat is found inside the abdominal cavity and wraps around internal organs, as opposed to subcutaneous fat which is stored just below the skin. Visceral fat, and in particular mesenteric fat, may be found in the abdomen, under the abdominal muscles. Visceral fat is associated with high blood pressure, increased risk of heart disease, insulin resistance and diabetes, stroke, some cancers, and continued presence in the body may contribute to these conditions. Though diet and exercise can help eliminate visceral fat, diet and exercise are not well-tolerated by the typical overweight patient. Visceral fat is more susceptible to destruction by cooling to cold temperatures which do not harm surrounding or nearby tissue such as blood vessels, nerves and lymph nodes. Thus, visceral fat can be killed with cooling to temperatures in the range of +10° C. to −60° C., and preferably in the range of +10° C. to −20° C., or the range of −20° C. to −40° C. If cooling is limited to this range, surrounding or nearby tissue will not be affected. Cryogenically deadened visceral fat will be removed by the body over the course of a few weeks. Methods and systems for cooling visceral fat while leaving surrounding tissue unharmed are disclosed in our prior International Patent Publication WO 2020/061202 (Mar. 26, 2020).
The mesentery, or mesentarium, is an organ that attaches the intestines to the posterior abdominal wall in humans and is formed by the double fold of peritoneum. It helps in storing fat and allowing blood vessels, lymphatics, and nerves to supply the intestines, among other functions.
The mesentery includes sections such as ascending, transverse, descending, and sigmoid mesocolons, the mesoappendix, and the mesorectum. The mesentery includes sheet-like sections that connect the intestines in the abdomen to the abdominal wall. The mesentery comprises two walls of peritoneum (the mesenteric membrane), with various arteries, veins and nerves disposed between the two walls and running through the mesentery to supply various organs. Also, the mesentery stores visceral fat, which, when excessive, leads to the ailments mentioned above.
The visceral/mesenteric fat in the sheet-like layered structure is not readily treated with cooling probes or methods of the prior art.
The methods and devices described below provide for reducing visceral fat within the mesenteric structure of the body by cooling visceral fat within the mesentery while leaving arteries, veins, nerves and lymph nodes within the mesentery, and the mesentery membrane, undamaged, and thereafter allowing natural processes of the body to eliminate the cooled visceral fat from the body. The system comprises a pair of flat-faced cooling probes (in the easiest implementation) configured for insertion into the abdomen and placement on opposite sides of a section of mesentery for application of cooling power to the mesentery, at temperatures in a range which kills visceral fat cells but does not harm other tissue (in our prior International Patent Publication WO 2020/061202, we referred to this as a non-ablative cold temperature). The flat-faced cooling probes have tissue-contacting surfaces supplied with cooling power, such as flow of a cooling fluid proximate the surfaces, and the cooling surface of each probe may be provided with positioning transmitters/sensors, operable to transmit and/or receive signal from corresponding transmitters/sensors on the other probe, to aid in determining the degree of alignment of the probes on opposite surfaces of the mesentery. The cooling power applied, and the length of time it is applied, may be determined based on the thickness of the mesentery as determined by positioning sensors embedded in the treatment devices and/or and conventional medical imaging such as optical (endoscopic or direct vision), fluoroscopy or ultrasonic imaging, or may be controlled in response to temperature measurements of the mesenteric structure while applying cooling power.
The results of the operation are illustrated in
Preferably, the probes are inserted endoscopically, through a portal or cannula inserted into the abdomen of the patient. With appropriate portal(s) in place, and appropriate insufflation applied to distend the abdomen and create working space (if necessary), the distal ends of probes which carry the cooling heads may be inserted through the portals and applied to the mesentery. Graspers with grasping jaws, or other retracting tools, can be inserted through the abdominal wall to hold the intestine and/or mesentery in a convenient configuration to facilitate application of the cooling heads. After the cooling operation, the cooling heads may be disengaged from the surfaces of the mesentery sheet. If the cooling operation has resulted in adhesion of the mesentery to the cooling heads, disengagement may be facilitated with active warming by applying energy to the heating elements, supplying warm fluid through the cooling fluid lumens, or waiting for passive warming to release the tissue from the cooling heads.
Warming elements 43 may be disposed on the distal surface, and wires for supplying electrical power to the warming elements may be disposed within the shaft and communicate with a power source outside the body. Warming elements, if provided, are connected to a power source 44 at the proximal end of the cooling probe.
Temperature sensors 45 may also be disposed on the cooling surface of one or both probes, and may be used by the surgeon to monitor the progress of the cooling operation and avoid under-cooling or over-cooling. Temperature sensors may also provide input to a control system, if used, which may be operable to control the flow and/or temperature of the cooling fluid to cool the tissue to the desired temperature. Otherwise, the surgeon may control the fluid flow manually, without the assistance of a control system which is operable to receive input from the temperature sensors and control fluid flow in response to the signals corresponding to temperature provided by the temperature sensors.
Position sensors 46 such as proximity sensors may be disposed on the cooling surface of each probe, and may be operable, in conjunction with a control system, to confirm that cooling heads on either side of a mesenteric structure are aligned with each other.
A control system 47 may be provided, programmed to control cooling fluid flow in response to operator input to initiate cooling, signals from the temperature sensors corresponding to the temperature of the visceral fat within the mesenteric structure, operator input to initiate warming, and also generate and output images to a display screen to provide information to the surgeon regarding the progress of the operations.
The return lumen 34r may be configured for connection to a collection tank for disposal or recirculation, or it may be open to atmosphere if the cooling fluid is a gas. The inner shaft may be rigid, so that it may be translated relative to the outer shaft to collapse the expandable structure when translated distally relative to the outer shaft and to expand, or facilitate expansion, of the expandable structure when translated proximally relative to the outer shaft.
The cooling fluid source 39 is operable to deliver cooling fluid through the cooling fluid supply lumen 34 and cooling fluid channels 38, to deliver cooling power to body tissue in contact with the distal surface. A warming fluid source 40, if provided, is operable to deliver warming fluid through the cooling fluid supply lumen 34 and cooling fluid channels 38, for use after the cooling operation, to deliver warming power to body tissue in contact with the distal surface. Alternately, the power source, if provided, is operable to deliver electrical power to the warming elements to apply warming heat to body tissue in contact with the distal surface, to release frozen tissue from the distal surface of the cooling head.
Any suitable cooling fluid may be used, including a solution of ethanol, ethanol in water, octafluoropropane, diethyl ether, or propylene glycol.
In use, a surgeon will access the abdomen by penetrating the skin and peritoneum 12 at one or more access ports, place appropriate portals in the penetrations, and insufflate the abdomen to create a working space, and insert an endoscope into the work space. The surgeon will insert appropriate retractors, such as the graspers 27 and 28 if necessary, retract abdominal organs as necessary to expose the mesentery sheet to the cooling probes, and insert cooling probes through portals into the abdomen. If the patient is in a prone position, the surgeon (or an assistant) will grasp the main organ to which the mesentery is attached (large intestine, small intestine, etc.) and lift it to allow the mesentery to hang down from the main organ, exposing the mesentery surfaces to the probes. (These steps are all optional, as the crux of the procedure may be accomplished with an open procedure, or with many variations in the steps of minimally invasive approaches.)
The surgeon will place one cooling probe on a first side of a mesentery structure (typically a sheet like structure) and place a second cooling probe on a second side of the mesentery structure, with the distal surfaces of the cooling heads of each cooling probe facing each other and aligned across the sheet, and press them together to ensure firm contact with the mesenteric structure. With the cooling heads aligned across the mesentery structure, the surgeon will initiate cooling fluid flow, from the cooling fluid source, through the supply lumen and channels in the distal faces of the cooling heads.
The surgeon will operate the cooling source and cooling probes to cool the mesenteric tissue trapped between the cooling heads to temperatures in the range of +10° C. to −60° C., and preferably in the range of +10° C. to −20° C., or the range of −20° C. to −40° C., and controlling the cooling probe to avoid cooling the visceral fat surrounding the distal end of the cooling probes to temperatures below about −40° C., to avoid cryogenic damage to blood vessels, nerves, lymph nodes and other structures within the mesentery, and the mesenteric membrane itself. In practice, it may be preferred to cool the tissue to a narrower range of +10° C. to −20° C. or −30° C., and avoiding cooling surrounding tissue below −30° C., and may be acceptable to cool the tissue to a broader range of +10° C. to −60° C., or more preferably to the range of −20° C. to −60° C., and avoiding cooling surrounding tissue below −60° C.
After cooling operations at one site, the cooling probes may be released from the mesenteric structure by warming the probe heads by energizing warming elements or passing warming fluid through the channels, or by passive warming with body heart. The process can be repeated to treat other areas of the mesentery. After the surgeon has treated one or more areas of the mesentery, the probes may be pulled from the abdomen, which may include collapsing the cooling heads by forcing a rigid inner shaft distally relative to the outer shaft, withdrawing or draining inflation fluid from the expandable structure, and pulling the probe through the portals.
The cooled visceral fat within the mesenteric structure is left in the body, to undergo cell death or elimination under any mechanism, within the mesenteric structure, to be resorbed by the body. The procedure may result in destruction and/or removal of the mesentery fat by processes including cryolipolysis (hydrolysis, cell disruption and inflammation), thermogenic fat metabolism without cell disruption, apoptosis (controlled cell death) or other natural process of the body.
For sufficiently thin mesenteric structures, both cooling heads may not be necessary to provide the cooling necessary for the treatment. If so, one of the cooling probes may be used in an inactive mode (operating a first cooling probe to cool tissue without operating the second probe to cool tissue disposed between the first distal surface of the first probe and the second distal surface of the second probe, for example), or may be replaced with a probe consisting of the expandable head, without cooling means, and this probe may be used as a backstop or anvil, for pressing the mesenteric structure into contact with the first cooling probe which will be operated as a cooling probe. Also, though the method is illustrated with probes with distal cooling surfaces suitable for trapping mesenteric tissue between two probes when the probes are inserted into the abdomen such the cooling heads can approach the mesenteric structure from opposite sides, the cooling surface can instead be disposed on a lateral surface of the cooling head, when, for example, the cooling heads might be disposed on opposing jaws of a clamp. Also, in cases where the surgeon cannot position device on either side of a mesentery structure, as in the case of the root of the mesentery, a single probe may be used, and operated independently of the second probe while pressing the cooling surface of the single probe against the root of the mesentery.
The results of the operation are illustrated in
Thus, as described above, the method of removing visceral fat from a mesenteric structure within an abdomen of a patient, includes the steps of (1) trapping a portion of the mesenteric structure between a first cooling head of a first cooling probe and a second cooling head of a second cooling probe, (2) operating the first cooling probe to cool tissue within the mesenteric structure while operating the second cooling probe to cool tissue within the mesenteric structure, and (3) operating the second cooling probe to cool tissue within the mesenteric structure. The cooling heads are preferably operated at the same time, with cooling power being applied from both sides of the mesenteric structure simultaneously. The method is accomplished with first cooling head having a first surface configured for contacting the mesenteric structure (contacting the mesenteric membrane) and cooling the mesenteric structure, and a second cooling head having a second surface configured for contacting the mesenteric structure (contacting the mesenteric membrane) and cooling the mesenteric structure, and the step of trapping the portion of the mesenteric structure comprises placing the first surface in contact with the mesenteric structure and placing the second surface in contact with the mesenteric structure, with the distal surface of the first probe aligned across the mesenteric structure with the distal surface of the second probe. The portion of the mesenteric structure trapped between the cooling probes may be a single sheet, or a folded double layer of a mesenteric sheet, or a mass of different geometry. The cooling heads are cooled by forcing cooling fluid from a reservoir through the channels. When accomplished in an endoscopic/laparoscopic procedure, the method is accomplished by inserting the first cooling probe into the abdomen through a first portal, inserting the second cooling probe into the abdomen through a second portal, pressing the flat distal surface of the first cooling head on a first side of the mesenteric structure, pressing the flat distal surface of the second cooling head on a second side of the mesenteric structure, the second side of the mesenteric structure being opposite the first side of the mesenteric structure.
While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species, and the various beneficial features may be employed in embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.
