Patent Publication Number: US-2023154355-A1

Title: Renal hilum surgical simulation system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a continuation application of U.S. application Ser. No. 16/428,769, filed May 31, 2019, which claims benefit of U.S. Provisional Patent Application No. 62/679,568, filed on Jun. 1, 2018 and U.S. Provisional Patent Application No. 62/791,450, filed on Jan. 11, 2019, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     This application relates to surgical training, and in particular, to simulated tissue structures and organ models for teaching and practicing various surgical techniques and procedures related but not limited to laparoscopic, endoscopic and minimally invasive surgery. 
     Laparoscopic surgery requires several small incisions in the abdomen for the insertion of trocars or small cylindrical tubes approximately 5 to 10 millimeters in diameter through which surgical instruments and a laparoscope are placed into the abdominal cavity. The laparoscope illuminates the surgical field and sends a magnified image from inside the body to a video monitor giving the surgeon a close-up view of the organs and tissues. The surgeon watches the live video feed and performs the operation by manipulating the surgical instruments placed through the trocars. 
     Kidney transplantation is the treatment of choice for patients with end-stage renal disease, which has rapidly increased in the last 10 years. There are currently 100,000 patients on the kidney transplant list, with many waiting 5-10 years for a kidney from a deceased donor. This has led to an increase in live donor nephrectomies, and in turn become a vital procedure for transplant surgeons to be proficient in to both minimize morbidity and mortality for the healthy donor, and to harvest the kidney in an optimal condition for transplantation. Laparoscopic donor nephrectomy (LDN) has since become the preferred surgical approach, as there are many advantages over open surgery, including decreased hospital stay, postoperative pain and morbidity, and increased donor satisfaction. However, while there are benefits to laparoscopic surgery, the complex surgical tasks involved place higher demands on the skills of the surgeon. 
     Simulation-based education has greatly enhanced laparoscopic surgical training by providing a safe and effective means for acquiring technical skills. However, despite the increased need for training on the LDN procedure, simulation training surgical simulation systems, simulators or models are lacking. As a result, trainees are limited to practicing the procedure in costly animal and cadaver labs or rely on experience gained through practice on patients in the operating room, which reduces operating room efficiency. To increase the safe conduct of the operation, increase the number of practitioners learning LDN, improve the skills of practitioners, reduce training costs and make training LDN easier, a LDN simulation model that focuses and isolates one or more of the most technically challenging steps in the operation, renal hilum dissection, is desirable and beneficial for reducing the learning curve of transplant trainees allowing them to achieve proficiency faster. In addition, a LDN-focused model or surgical simulation system would enable trainees to practice in a low-risk environment and potentially reduce the need, and associated costs, for animal and cadaver labs. 
     SUMMARY 
     In accordance with various embodiments of the present invention, a renal hilum surgical simulation system is provided. The surgical simulation system comprises a plurality of penetrable simulated tissue layers, a pocket disposed between the plurality of penetrable simulated tissue layers and encased by the peripheries of the plurality of penetrable simulated tissue layers, a plurality of fibrous layers disposed between the plurality of penetrable simulated tissue layers and at least one of a simulated renal organ and vasculature disposed between the plurality of fibrous layers and enclosed within the pocket. 
     In accordance with various embodiments, a renal hilum surgical simulation system is provided. The system in various embodiments comprises a first penetrable layer having an upper and lower surface and a second penetrable layer having an upper and lower surface. In various embodiments, the periphery of the upper surface of the second penetrable layer is connected to a periphery of the lower surface of the first penetrable layer and in various embodiments a pocket is disposed between the first and second penetrable layers. The pocket in various embodiments is delimited and encased by the peripheries of the first and second penetrable layers connected together. A plurality of fibrous layers in various embodiments are disposed between the first and second penetrable layers and in various embodiments at least one simulated renal vasculature is disposed between the plurality of fibrous layers and enclosed within the pocket. 
     In accordance with various embodiments, a renal hilum surgical simulation system comprises a first penetrable layer having an upper and lower surface and a second penetrable layer having an upper and lower surface. In various embodiments, a periphery of the upper surface of the second penetrable layer is connected to a periphery of the lower surface of the first penetrable layer and in various embodiments a pocket disposed between the first and second penetrable layers. The pocket in various embodiments is delimited and encased by the peripheries of the first and second penetrable layers connected together. A plurality of fibrous layers in various embodiments are disposed between the first and second penetrable layers and in various embodiments at least one simulated renal organ disposed between the plurality of fibrous layers and enclosed within the pocket. 
     In accordance with various embodiments, a renal hilum surgical simulation system comprises a first penetrable layer having an upper and lower surface and a second penetrable layer having an upper and lower surface. In various embodiments, a periphery of the upper surface of the second penetrable layer is connected to a periphery of the lower surface of the first penetrable layer and in various embodiments a pocket is disposed between the first and second penetrable layers. The pocket in various embodiments is delimited and encased by the peripheries of the first and second penetrable layers connected together and a plurality of fibrous layers in various embodiments are disposed between the first and second penetrable layers. A plurality of simulated renal vasculature in various embodiments are disposed between the plurality of fibrous layers and enclosed within the pocket and/or at least one simulated renal organ in various embodiments is disposed between the plurality of fibrous layers and enclosed within the pocket. 
     In accordance with various embodiments, a renal hilum surgical simulation system is provided and comprises a simulated renal vasculature and/or a simulated renal organ. In various embodiments, a renal hilum surgical simulation system is provided and comprises at least one fibrous layer, e.g., batting. In various embodiments, a renal hilum surgical simulation system or renal hilum laparoscopic donor nephrectomy surgical simulation system is provided. In various embodiments, a surgical simulation system is provided and comprises a simulated vasculature, a simulated organ, a simulated renal vasculature, a simulated renal organ and/or any combinations thereof and/or individually. In various embodiments, the system comprises a first penetrable layer having an upper and lower surface and a second penetrable layer having an upper and lower surface. In various embodiments, a periphery of the upper surface of the second penetrable layer is connected to a periphery of the lower surface of the first penetrable layer and in various embodiments, the first and second penetrable layers are made of silicone. A pocket in various embodiments is disposed between the first and second penetrable layers and in various embodiments, the pocket is delimited and encased by the peripheries of the first and second penetrable layers connected together. A top fibrous layer in various embodiments has an upper and lower surface and in various embodiments is disposed under the first penetrable layer with the lower surface of the first penetrable layer next to and in contact with the upper surface of the top fibrous layer. A bottom fibrous layer in various embodiments has an upper surface and a lower surface and in various embodiments is disposed above the second penetrable layer with the upper surface of the second penetrable layer next to and in contact with the lower surface of the bottom fibrous layer. A middle fibrous layer in various embodiments has an upper surface and a lower surface and in various embodiments is positioned between the top fibrous layer and the bottom fibrous layer. A first simulated renal vasculature in various embodiments is connected to upper surface of the bottom fibrous layer and the lower surface of the middle fibrous layer and in various embodiments, a second simulated renal vasculature is connected to the lower surface of the top fibrous layer and the upper surface of the middle fibrous layer. In various embodiments, the top, bottom and middle fibrous layers and the first and second simulated renal vasculatures are enclosed within the pocket. 
     Many of the attendant features of the present invention will be more readily appreciated as the same becomes better understood by reference to the foregoing and following description and considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present inventions may be understood by reference to the following description, taken in connection with the accompanying drawings in which the reference numerals designate like parts throughout the figures thereof. 
         FIG.  1    is an exploded view of a renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  2    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  3    is a cross-sectional view of a renal vein and artery in accordance with various embodiments of the present invention. 
         FIG.  4 A  is a side view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  4 B  is a top view of assembled portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  5 A  is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  5 B  is a top view of assembled portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  6    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  7    is a top view of assembled portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  8    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  9    is a top view of assembled portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  10    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  11    is a top view of assembled portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  12    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  13    is an exploded perspective view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  14    is an exploded side view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  15    is a top view of portions of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  16    is a top view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  17    is a perspective view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  18    is a perspective view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
         FIG.  19    is a side view of the renal hilum surgical simulation system in accordance with various embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In a LDN procedure, renal hilum dissection is one of the more challenging and high-risk steps due to the need to mobilize multiple critical structures. Currently, there is an unmet need for simulated models or surgical simulation systems that trainees can practice on to become proficient at this step of the operation. A simulated model or surgical simulation system of the renal hilum would reduce the learning curve by allowing surgical trainees to practice the required dissection repeatedly in a low-risk environment. To be effective, the surgical simulation system should allow for complete dissection of specific structures within the renal hilum from a laparoscopic approach, which includes one or more of the following simulated anatomy and landmarks to be present and identifiable in the model or surgical simulation system: kidney, adrenal gland, renal vein, renal artery, ureter, gonadal vein, adrenal vein, lumbar vein, and aorta. These structures should be anatomically correct and/or be made of materials that have a similar simulated tissue reaction encountered in the LDN procedure. In addition, these structures may be surrounded by simulated dissectible areolar tissue of appropriate density to provide realistic tactile feedback. Practice on the surgical simulation system can promote identification of the appropriate anatomy and acquisition of appropriate tissue handling and dissection skills required for the procedure. 
     The renal hilum surgical simulation system in accordance with various embodiments allows a trainee to focus on the skills necessary to practice the most challenging steps within a LDN procedure. To provide a realistic procedural training environment, in various embodiments, the surgical simulation system is positioned appropriately. To further enhance the training environment, the surgical simulation system uses simulated materials to represent the various anatomical landmarks as well as materials to simulate areas of dissectible tissue, which provide key visual and tactile feedback useful for the training of an LDN procedure. In order to simulate the tactile feel of the anatomical structures encountered during the LDN procedure, in accordance with various embodiments, specific combinations of materials, construction, and design have been chosen for various components found within the surgical simulation system. 
     Turning now to  FIG.  1   , an exploded perspective view of a renal hilum surgical simulation model or system  10  according to various embodiments of the present invention is shown. The inner contents (anatomical structures and fibers) of the surgical simulation system  10  are encapsulated between two layers of silicone, a top penetrable layer  12  and a bottom penetrable layer  14 , that are adhered together to create a closed pocket. Inside the pocket, the top outermost layer is a top fibrous layer  16  constructed of a simulated dissectible tissue area made of multiple layers of sheets of polyester fibers, e.g., batting, adhered using small amount of silicone or adhesive that the surgeon is to dissect or cut through in order to uncover and reach the anatomical structures encountered in the LDN procedure. This dissection area comprising of the multiple layers of polyester fibers, such as a half-fibrous layer  18 , that are adhered together, fiber to fiber, e.g., batting to batting, as well as fiber, e.g., batting, to anatomical simulated structures are created to demonstrate the varying densities of the anatomy found in the body. In accordance with various embodiments, one or more of the layers are planar and/or stacked relative to each other. 
     In accordance with various embodiments, a layer of simulated anatomical landmarks is provided. The simulated anatomical landmarks in various embodiments comprise a simulated kidney  20 , adrenal gland  22 , ureter  24 , and/or aorta  26 . While none of these components should be dissected or cut during the simulated procedure, these landmarks are included in the surgical simulation system  10  to help orientate and/or educate the trainee. For example, the simulated ureter  24  should be identified but not touched, and is used as a tool to navigate to the location of the gonadal vein  28 . Although the simulated landmarks should not be touched or manipulated by the trainee, one or more of these simulated anatomical structures includes one or more visual characteristics such as size, shape, color and/or any combination thereof, to simulate anatomy and/or to pose as indicators to allow for orientation within the simulated environment. In various embodiments, one or more of these simulated anatomical structures also comprises one or more tactile characteristics, such as texture, resiliency, elasticity and/or any combination thereof to further enhance identification of the simulated landmarks and/or as assessment and/or educational indicators. For example, in various embodiments, one or more of the simulated landmarks holds its shape until cut or excessively manipulated and thus if inadvertently cut or otherwise unduly manipulated, the simulated landmarks would reflect this treatment and thereby providing an assessment for an evaluator and/or educational indicator for a trainee. 
     During the simulated procedure, the simulated gonadal vein  28 , adrenal vein  30 , and lumbar vein  32  are located and circumferentially dissected, or skeletonized. During this skeletonization, the surgeon may pull up on the veins in order to make cuts and dissect through the fibers or batting. This is one of the most challenging steps in the procedure as the veins are very fragile and will break or tear if incised or if too much force is put on them. For surgeons to become comfortable or proficient in these steps of the procedure, they must understand the force required to manipulate the veins during dissection without harming them and thus the necessity to simulate the fragility of the veins. 
     In accordance with various embodiments, the simulated gonadal vein  28 , adrenal vein  30 , and/or lumbar vein  32  are made of a silicone or silicone foam that is molded into thin flat structures to simulate fragility of the various veins. It should be noted that gonadal, adrenal, and lumbar veins found within the human body are hollow cylindrical structures through which blood flows and have diameters of 3 mm, 4 mm, 2 mm respectively. As such, in accordance with various embodiments, while the simulated gonadal vein  28 , adrenal vein  30 , and/or lumbar vein  32  are not exact replicas of anatomy, e.g., in size and/or shape, these simulated veins are provided, for example, in size and/or shape along with the choice of material, e.g., silicone, to aid in the manufacturing process and replicate the tactile feel of the corresponding structures. 
     In various embodiments, the simulated gonadal, adrenal, and lumbar veins,  28 ,  30 ,  32  includes one or more cuts or notches  50  along their lengths in predetermined locations as shown in  FIG.  2   . These predetermined notches  50  create weak or break points at specific locations, allowing the simulated vessels to simulate the fragility of such vessels. Additionally, in various embodiments, if excessive force or manipulation is applied to the simulated veins, the simulated veins will separate at one or more of the notches  50 . A separated or torn vessel can provide an assessment and/or educational indication for or regarding the trainee&#39;s specific performance of or during the simulated procedure. Furthermore, the location of where the tear occurred, as indicated at a particular notch or weak point, can further assist in providing a more detailed assessment and/or educational indicator of the force or manipulation applied to the torn simulated vessel. It should however be noted that simulated vessels with predetermined notches may inhibit assessment of the simulated vessels after the procedure is performed, e.g., identifying new versus old or pre-installed notches may prove difficult, and as such predetermining the location and/or size of the notches or weak points can assist in reducing or eliminating this inhibition. 
     In various embodiments, the simulated lumbar vein within the surgical simulation system is under tension. The simulated lumbar vein, in various embodiments, is pulled taut and attached to the back of the model or surgical simulation system, putting it on tension. Placing the simulated lumbar vein under tension allows the simulated vein or portions thereof to snap when nicked or excessively tugged during circumferentially dissection. This snapping simulates or represents the fragility of the simulated lumbar vein as the amount of force used to snap the simulated vessel is similar to the amount of force to similarly affect a non-simulated lumbar vein. 
     In various embodiments, the surgical simulation system  10  comprises a simulated renal vein  34  and a simulated renal artery  36 . The simulated renal vein  34  and renal artery  36  are separated from the surrounding fibers or batting (i.e. skeletonized) during the simulated procedure. The simulated renal vein  34  and renal artery  36  have much larger diameters (approximately 1.2 cm and 6 mm, respectively) than that of the simulated gonadal, adrenal, and lumbar veins  28 ,  30 ,  32  giving them more integrity and/or strength to simulate the tactile differences in the simulated renal vein  34  and renal artery  36 . 
     In accordance with various embodiments, with reference to  FIG.  3   , the illustrated simulated renal artery  36  has a smaller overall diameter but thicker wall relative to the simulated renal vein  34  having a larger diameter and thinner wall. In various embodiments, the simulated renal artery and vein are made of silicone and, in various embodiments, the simulated renal artery comprises a thick layer of silicone providing a thicker wall thickness of the simulated vessel. In various embodiments, the layer of silicone is made thicker by applying multiple thin layers or coats of wet or dry silicone. As a result of a thicker wall, the vessel will be harder to penetrate, i.e., the simulated renal artery is harder to penetrate versus the simulated renal vein. The simulated renal vein, in various embodiments, has a thin layer of silicone to provide a thin wall thickness. As a result, the vessel, e.g., the simulated renal vein, will be easier to puncture or nick. 
     Providing a contrast in structural integrity of the renal vein and renal artery further provides or enhances the simulation and/or the training and/or assessment indications as the tactile force allowed during the simulated procedure to circumferentially dissect around each of the structures without puncturing or otherwise unduly disrupting them is different for each vessel. In various embodiments, the thinner walls of renal vein  34  are fragile and/or made with a thinner layer of material. In contrast, in various embodiments, the simulated renal artery  36  is made of a thicker layer or layers of material. Both vessels are made of or molded from silicone and/or a similar fragile material that will hold its shape including conductive material. 
     In various embodiments, the simulated renal vein  34  and/or renal artery  36  are filled with fluid or the like to further mimic anatomy and/or for assessment or training indicators. For example, if either of the vasculature is punctured, fluid may be expelled or trickle out of the simulated vessels and thereby provide a visual indication of punctured vasculature and potentially indicating further training or decreased proficiency of the trainee. 
     In  FIGS.  4 A-B , the simulated adrenal vein  30 , gonadal vein  28 , and lumbar vein  32  are adhered or otherwise attached to the simulated renal vein  34  at a renal vein adhesion area  52  and, in various embodiments, through adhesion of silicone to silicone. The renal vein adhesion area  52  is depicted by a rectangular box in  FIG.  4 B . Even though the adhesion area is depicted as a rectangular shape, the adhesion area may be any shape. The attachment area  52  is illustrated or referred throughout as a guide and as an exemplary way to show where the components are adhered or otherwise attached or where adhesive or the like is applied. In various embodiments, the simulated gonadal vein  28 , adrenal vein  30 , and lumbar vein  32 , are molded separately and are minimally and/or weakly adhered to the renal vein  34  to increase the fragility of the simulated veins for, e.g., assessment and/or training, when the simulated vessel is put on tension and dissected around. The weak adhesion in various embodiments is achieved by using a weak adhesive or similar attachment, such as a silicone with a softer durometer, and/or removing connector  33  and attaching the simulated veins  28 ,  30 ,  32  directly to the simulated renal vein  34 . 
     With reference to  FIGS.  5 A-B , a second vasculature subassembly is illustrated in accordance with various embodiments. As illustrated, the simulated renal artery  36  is adhered or otherwise attached to the simulated aorta  26  by a silicone-to-silicone adhesion and, in various embodiments, with consistent hard durometer silicone. In various embodiments, wet silicone is employed as an adhesive and allowed to cure to solidify the connection. The aorta adhesion area  52  is depicted by a rectangular box in  FIG.  5 B . In various embodiments, the simulated aorta  26  has a semi-cylindrical shape as seen for example in  FIG.  14   . 
     Turning now to  FIG.  6   , a back fibrous layer  38  is provided. The back fibrous layer  38  in various embodiments is made of or includes batting. In various embodiments, the back fibrous layer is a rectangular, substantially planar layer of polyfill or other fibrous material. The back fibrous layer  38  includes a hole or opening  54  through which the lumbar vein  32  is passed. The opening  54  is unique to the surgical simulation system  10  and is not anatomically correct. The second vasculature subassembly comprising the renal artery  36  and aorta  26  is adhered to the back or first fibrous layer  38  using adhesive as shown in  FIG.  7   . The adhesion area  52  is shown to be substantially under the entire second subassembly. 
     Turning now to  FIG.  8   , in accordance with various embodiments, a second fibrous layer  40  is adhered to the simulated renal artery  36  and aorta  26  of the second vasculature subassembly. The second fibrous layer  40  is made of or includes batting. In various embodiments, the second fibrous layer is a rectangular, substantially planar layer of polyfill or other fibrous material. The second fibrous layer  40  is also adhered to the back or first fibrous layer  38  with an adhesion area  52  indicated by the large rectangle. The second fibrous layer  40  also contains a hole or aperture  56  extending from the top and through to the bottom surface of the second fibrous layer  40 . The simulated lumbar vein  32  passes through this hole  56  and the hole  54  in the back fibrous layer  38  and, as such, the holes  54 ,  56  are aligned when the layers are stacked such that their perimeters are substantially congruent to fit inside the pocket. Turning now to  FIG.  9   , the first vasculature assembly, comprising the simulated gonadal vein  28 , adrenal vein  30 , lumbar vein  32  and renal vein  34 , are adhered to the second fibrous layer  40  with an adhesion area  52  being under the renal vein  34 , adrenal vein  30  and gonadal vein  28  as shown in  FIG.  9    with the adhesion area  52  shown by three rectangles. The simulated lumbar vein  32  is passed through the holes  56  and  54  in the fibrous layers  40 ,  38 . 
     Turning now to  FIG.  10   , the simulated kidney  20 , ureter  24  and adrenal gland  22  are connected to the simulated renal vein  34  and adrenal vein  30  and to the second fibrous layer  40 . The simulated ureter  24  is adhered to or otherwise attached to the back of the simulated kidney  20 . The kidney  20  is adhered to the top end of the simulated renal vein  34  as well as the second fibrous layer  40 . The simulated ureter  24  is adhered to the second fibrous layer  40 . The simulated adrenal gland  22  is adhered to the simulated adrenal vein  30  as well as the second fibrous layer  40 . The simulated adrenal gland  22  is not adhered to the simulated kidney  20 . The adhesion areas  52  are demonstrated by the rectangular shapes in  FIG.  10    and the non-adhesion area  58  between the adrenal gland  22  and the kidney is demonstrated by the ellipse in  FIG.  10   . 
     Turning now to  FIG.  11   , the half fibrous layer  18  is adhered to the simulated kidney  20 , the simulated adrenal gland  22 , the adrenal vein  30 , the renal vein  34 , and the second fibrous layer  40 . The adhesion area  52  is shown by a rectangle substantially completely underneath the half fibrous layer  18 . The half fibrous layer  18  is provided to simulate a denser dissectible areolar tissue found within a patient. In various embodiments, the half fibrous layer  18  is created from cutting the larger piece of fibrous material, e.g., batting, in half, length-wise and pulling apart the layers of the batting to create a thinner piece to add to the density of the dissectible tissue. In accordance with various embodiments, the fibers or fibrous material encapsulate and surround one or more or every simulated anatomical structure. The multiple layers of fibrous material, e.g., batting, provide varying density of dissectible material in which a surgeon has to navigate. As stated previously, the simulated lumbar vein  32  passes through the holes  54 ,  56  in the fibrous layers  38 ,  40 . When the surgical simulation system  10  is flipped over, back side facing up, as shown in  FIG.  12   , the simulated lumbar vein  32  is pulled through the holes  54 ,  56  to expose it on the back side. 
     With reference to  FIGS.  12 - 13   , the surgeon must circumferentially dissect around the renal vein  34 . In accordance with various embodiments, the contents of the surgical simulation system  10  are encapsulated between the top silicone layer  12  and the bottom silicone layer  14 . The bottom silicone layer  14  of the surgical simulation system  10 , in various embodiments, is constructed of uncured silicone, which is adhered to the top fibrous layer  16  around the outside border, creating a pocket upon curing together with all of the components retained by and located inside the pocket. Because the bottom silicone layer  14  of silicone is uncured during manufacturing of the assembly, the back fibrous layer  38  will also adhere to the wet silicone. If the back fibrous layer  38  becomes too saturated with uncured silicone, it can undesirably start to adhere the simulated renal artery  36  and aorta  26  to the bottom silicone layer  14 , which would prevent the ability of the surgeon trainee to circumferentially dissect around the renal artery of the simulated LDN procedure. To prevent or reduce this undesirable adhesion, an adhesion blocker  42  is used to ensure that the simulated renal artery  36  can be dissected circumferentially around as shown in  FIG.  13    with the dissection area  60  demarked with a ellipse. The adhesion blocker  42 , in various embodiments, is made of a silicone sheet, molded to the approximate thickness of the bottom silicone layer  14 , and cut to the size of the renal artery  36  to prevent any undesired adhesion. In various embodiments, the adhesion blocker  42  is placed or used such that it does not obstruct the lumbar vein  32 , since the lumbar vein  32  will ultimately be adhered to the back of the surgical simulation system  10 , bottom silicone layer  14 . The adhesion blocker  42 , in various embodiments, is adhered to the back fibrous layer  38  shown, for example, by the rectangular adhesion area, without excess force applied, so as not to saturate the fibrous material, e.g., batting, through and adhere the simulated renal artery  36  or aorta  26 . 
     With reference to  FIG.  14   , the simulated lumbar vein  32 , in various embodiments, is adhered to the simulated renal vein  34  and then passes through the second fibrous layer  40  and back fibrous layer  38  and adhered to the bottom silicone layer  14 . In accordance with various embodiments, the adherence of the lumbar vein  32  to the bottom silicone layer  14  occurs while the model or surgical simulation system contents are placed on the uncured bottom silicone layer  14 . Upon curing of the bottom silicone layer  14 , the contact of the lumbar vein  32  with the uncured bottom silicone layer  14  will form the necessary adhesion. In various other embodiments, the lumbar vein  32  is adhered to the second fibrous layer  40  and back fibrous layer  38  at their respective holes  56 ,  54 . 
     In various embodiments, in the surgical simulation system, the layers are adhered together by intertwining the surrounding fibrous layers, holding simulated structures in place with or without the use of silicone or silicone adhesive. 
     In various embodiments, fibers of the fibrous, e.g., batting, layers are mesh through one another to create a knit matrix and/or when push through the silicone components a slight adhesion of batting to silicone is created. As such, adequate adhesion of tissue (e.g., batting) to the organs (e.g., silicone) for a surgeon to dissect through in the simulated procedure is provided. Such knit matrix can also avoid or reduce the use of silicone glue layers that can be difficult to control for consistency throughout the surgical simulation system or cause unwanted residues. 
     With reference now to  FIGS.  15  and  16   , in various embodiments, to ensure identification of the simulated ureter  24  and gonadal vein  28 , the simulated ureter  24  and gonadal vein  28  are visible through the border/perimeter  62  of the surgical simulation system  10 . In accordance with various embodiments, the border/perimeter  62  is formed by the top silicone layer  12  adhering together with the bottom silicone layer  14  to form a pocket  64 . The simulated ureter  24  and gonadal vein  28  are visible through the top silicone layer  12  at the border/perimeter  62  of the surgical simulation system  10 . These landmarks pose as an indicator as to where the surgeon should start dissection of the surgical simulation system  10 . In order for these landmarks to be visible through the border  62 , the simulated ureter  24  and gonadal vein  28  extend outwardly past the fibrous layers and into the border, highlighted by circle  63  in  FIGS.  15 - 16   . In various other embodiments, the color and/or opacity of the top silicone layer  12  is distinguished with respect to the simulated ureter  24  and gonadal vein  28  to allow for visibility of the landmarks through the top silicone layer  12 . 
     With reference to  FIGS.  17 - 19   , in accordance with various embodiments, the renal hilum dissection surgical simulation model  10  may include two or more holes along the border  62  for mounting on a stand  66  having a base  68  with at least two upstanding posts  70  extending upwardly from the base  68 . The posts  70  are passed through the holes in the border  62 . The stand  66  with the surgical simulation model  10  can then be located inside a cavity of a laparoscopic trainer  72  for the procedural practice to begin. The trainer defines a cavity between a top cover and a base. The cavity is obscured from direct view by the practitioner and a scope is inserted through the top cover to capture a live video feed of the cavity, which is displayed on a monitor to the practitioner. The practitioner or trainee inserts various instruments through the top cover and performs the simulated procedure on the surgical simulation system  10  inside the cavity. The stand  66  serves to support the surgical simulation model or system  10  inside the trainer  72 . In various embodiments, the surgical simulation system  10  contains one or more holes or apertures in each of the top two corners of the border  62 . These holes interface with the posts  70 . In various embodiments, the stand  66  includes four posts  70 . In various embodiments, the border  62  is made from elastic silicone material that stretches and returns to its original shape and the holes of the border are stretched to fit over the post  70  and then return to a tight fit to secure the surgical simulation system  10  into place on the posts  70  of the base  68 . The placement of the holes on the posts  70 , along with the angled position of a flap  44 , allow for the surgical simulation system  10  to be placed in a variety of angles with respect to the base  68  that may be necessary to complete the simulated procedure. In various embodiments, in order to stabilize the upper corners of the surgical simulation system  10 , clips  74  within the trainer  72  are used to pull the surgical simulation system upright and/or hold it in position. In accordance with various embodiments, a stand or stable structure and/or similar attachments to the surgical simulation system and/or the trainer may hold the surgical simulation system stable in an angled position for the simulated surgical procedure. 
     In various embodiments, the surgical simulation system includes, is integrated or is embedded with a frame that supports, suspends and/or angles the surgical simulation system and in various embodiments in order to replicate or simulate the angled position of a patient. The surgical simulation system is removably attached to the frame and in various embodiments, the frame is removably attached to a surgical trainer. In such embodiments, the apertures within the border and/or the additional portion provided by the border may be removed along with the flap, the associated attachment and/or the additional portions provided by the surgical simulation system providing the flap, attachment and/or border. 
     During an LDN procedure, the patient is situated lying down on their side with a slight backwards tilt. In order to replicate or simulate the angled position of a patient, the renal hilum dissection surgical simulation system  10 , according to various embodiments, incorporates a flap  44  designed to be used as a support stand. Looped side of a hook-and-loop type fastener  46 , such as VELCRO®, is adhered to the flap  44  and configured to mate with the opposite or hooked side of the hook-and-loop type fastener  46  located on the bottom floor of the trainer  72 . The flap  44  extends from the bottom side of the surgical simulation system  10  and in various embodiments, is constructed a soft and flexible yet durable silicone that allows it to bend while maintaining its structural integrity. In various embodiments, the flap  44  is flexible so that two pieces of the hook-and-loop type fastener  46  can mate, while creating a bent stand for which to hold the surgical simulation system into the desired angle and position within the laparoscopic trainer  72 . The flap  44  is used in conjunction with or without the stand  66 . Attachment of the flap  44  to the floor of the trainer may vary and in various embodiments, the hook-and-loop type fastener may be replaced with or further include, for example, one or more snaps, magnets, posts or clips, and/or may extend through, attach to or be adhered to an intermediary component, e.g., an extension of base  68 , between the attachment/surgical simulation system and the floor of the trainer. The attachment of the surgical simulation system allows the surgical simulation system to be removable and thus eases replace-ability, repositioning or reorientation of the surgical simulation system. Such attachment or positioning of the various portions of the surgical simulation system relative to the trainer ensures that the orientation or angled position of the surgical simulation system replicates the orientation or position of the patient and in various embodiments ensures the tactile feedback, flexibility or other features provided by the surgical simulation system are not sacrificed and/or the simulated LDN procedure compromised. 
     In various embodiments, other variations to the surgical simulation system  10  may include alteration of the anatomical structures inside the pocket to include abnormal, diseased, or varying anatomy. Such anatomy could include the right renal hilum or the inclusion of additional lumbar veins and/or tumors. In other embodiments, the surgical simulation system  10  is dipped or soaked in water or other liquid to better represent the environment of a patient. For example, when the fibrous or batting layers become saturated with liquid they tend to become denser and more adhered. This allows, in various embodiments, for more applicable and accurate representation of the difficulty of the LDN procedure. Instead of a liquid such as water, the pocket  64  could also be filled with a gel like substance. 
     In various embodiments, the arrangement and/or composition of the various portions and components are provided to vary the difficulty of the surgical simulation system and thereby vary the simulated surgical procedure to enhance surgical training and surgical skill assessment. Such examples are described throughout the description and provided in the claims that may seem arbitrary but again are included or excluded to vary and adjust the difficulty the surgical simulation system to enhance surgical training and skill assessment. Some of these examples can include varying fibrous layer densities, exaggerating or underplaying simulated renal vasculature and/or organ shapes, dimensions and/or tactile response, saturating fibrous layers with liquid, creating simulated vasculature paths, e.g., a simulated renal vasculature threaded or extended through at least one opening in one or more or different fibrous layers, and/or varying the coloring and/or composition of the simulated renal vasculature, organs and/or surrounding structures. 
     In various embodiments, both sides or layers of the surgical simulation system are penetrable to ensure or further assess surgical skill such that if mishandling or manipulation of the simulated tissue, e.g., too much force is used, a noticeable puncture or opening in the opposing side of the surgical simulation system would be visible. Likewise, the thickness or distance between the layers are minimal, e.g., a fraction of the length or width of the surgical simulation system or the pocket contained therein, to further test or enhance the assessment of the surgical skill or effective operation of the simulated surgical procedure. 
     In various embodiments, the surgical simulation system is so confined to limit the working space available to simulate the surgical procedures. Likewise, the size of the pocket, for example, can be modified to further limit the operational space and thereby increase the difficulties of the simulated surgical procedure. Additionally, the number and/or size of the components and combinations thereof are further limited to enhance portability of the surgical simulation system, operation within a trainer, e.g., a portable laparoscopic trainer and/or further focus the surgical trainee on the specific simulated procedure. Similarly, omitted features or reduction of sizes or shapes are provided to enhance the surgical simulation system, e.g., increase difficulties or focus on the specific simulated surgical procedure, even though such differences or changes may not be anatomically correct. In various embodiments, the surgical simulation system includes at least one simulated renal vasculature, e.g., renal vein, renal artery, and/or the like and/or other vasculature/vessels provided herein, and/or at least one simulated renal organ, e.g., adrenal gland, kidney and/or the like and/or other organs/glands provided herein. 
     The above description is provided to enable any person skilled in the art to make and use the surgical simulation system or systems and perform the methods described herein and sets forth the best modes contemplated by the inventors of carrying out their inventions. Various modifications, however, will remain apparent to those skilled in the art. It is contemplated that these modifications are within the scope of the present disclosure. Different embodiments or aspects of such embodiments may be shown in various figures and described throughout the specification. However, it should be noted that although shown or described separately each embodiment and aspects thereof may be combined with one or more of the other embodiments and aspects thereof unless expressly stated otherwise. It is merely for easing readability of the specification that each combination is not expressly set forth. 
     Although the present invention has been described in certain specific aspects, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that the present invention may be practiced otherwise than specifically described, including various changes in the size, shape and materials, without departing from the scope and spirit of the present invention. Thus, embodiments of the present invention should be considered in all respects as illustrative and not restrictive.