Patent Publication Number: US-2023149646-A1

Title: Dual Suction Tube

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. Non-Provisional Patent Application No. 16/280,107, which was filed on Feb. 20, 2019. The entire content of the foregoing application is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a dual suction tube for surgeries and procedures involving the human upper airway. 
     BACKGROUND 
     Use of laryngeal mask airway devices for upper airway surgeries has been accepted as an alternative to the use of endotracheal tubes. A reinforced flexible laryngeal mask is generally preferred because its flexible, longer and thinner airway channel offers better access to the surgical field than other types of laryngeal mask. When placed properly, a laryngeal mask covers the glottis and protects the glottis and subglottic area from contamination with blood or other fluids that accumulates in the pharynx during upper airway surgery. However, the glottic seal formed by the mask is variable and dynamic, depending on numerous factors. As a result, aspiration due to leaking of blood or other fluids into the glottic area and the trachea has been reported in cases of laryngeal mask use during upper airway surgeries. In addition, the flexible laryngeal mask, like other first-generation laryngeal masks, typically does not prevent gastric insufflation during positive pressure ventilation, which is generally believed to lead to a higher risk of aspiration of gastric contents and subsequent complications. As a result, safety concerns surrounding the application of flexible laryngeal masks in upper airway surgeries persist in general. Furthermore, leaking of blood into the stomach may cause gastric irritation and possible increased incidence of postoperative nausea and vomiting. 
     SUMMARY 
     Exemplary embodiments of the present disclosure relate to airway devices, systems, and associated methods. Embodiments of the airway devices, systems, and methods can achieve ventilation of lungs through a mask that seals around the glottis and connects to a flexible airway channel, while also providing evacuation of gastric and/or pharyngeal body fluid and/or blood through a channel-ampulla-drain system integrated with the mask during upper airway surgeries or procedures. Exemplary embodiments of the present disclosure can improve the safety of airway management and lung ventilation for upper airway surgeries. For example, embodiments of the present disclosure can minimize the risk of aspiration of blood or other fluid accumulated in the pharynx as well as the risk of aspiration of gastric contents during upper airway surgeries. 
     In accordance with embodiments of the present disclosure, a laryngeal mask airway system is disclosed. The system includes an airway channel portion including an airway channel and a mask portion operatively coupled to the airway channel portion via an airway channel-mask junction. The mask portion includes a mask and an ampulla. The ampulla is disposed at a distal end of the mask portion and includes ports. The mask portion can also include a pharyngeal suction channel and/or a gastric-pharyngeal access channel. For embodiments that include the pharyngeal suction channel, the pharyngeal suction channel can extend through the mask portion from the airway channel-mask junction and terminate at one of the upper ports the ampulla. For embodiments that include the gastric-pharyngeal access channel, the gastric-pharyngeal access channel originates with an opening at a proximal end of the mask portion in proximity to the airway channel-mask junction and terminates at one of the upper ports of the ampulla. A ramp can be formed on the mask that slopes towards the opening of the gastric-pharyngeal access channel. The gastric-pharyngeal access channel can have an oval cross-sectional shape. 
     A lower port of the ampulla can be opposingly spaced from the upper port associated with the gastric-pharyngeal access channel and can open towards an esophagus of a human when the mask portion is placed in the hypopharynx of the human. This lower port can have a funnel-shape with first cross-sectional dimensions at the ampulla and second cross-sectional dimensions at a distal end of the lower port. A first cross-sectional area of the lower port at the ampulla is greater than the second cross-sectional area of the lower port at the distal end of the lower port. The distal end of the lower port can include a valve, which can be formed by a plurality of leaflets. In a closed position, adjacent ones of the plurality of leaflets of the valve engage each other to form a center opening. The gastric-pharyngeal access channel can have a third cross-sectional area that is greater than the cross-sectional area of the lower port opposing the upper port connected to the gastric-pharyngeal access channel. 
     In accordance with embodiments of the present disclosure, the system can include at least one pharyngeal drain formed on the mask. The at least one pharyngeal drain can be operatively coupled to one of the ports of the ampulla. For embodiments, that include a second pharyngeal drain, the second pharyngeal drain can be operatively coupled to another one of the ports of the ampulla. 
     In accordance with embodiments of the present disclosure, the system can include a pharyngeal suction channel that extends from a proximal end of the airway channel portion to the fourth port of the ampulla. A first portion of the pharyngeal suction channel can be formed within or outside of the airway channel and a second portion of the pharyngeal suction channel can be formed within the mask. The first portion of the pharyngeal suction channel can be formed by a suction catheter. For embodiments in which the first portion of the of the pharyngeal suction channel is formed outside the airway channel, the first portion can be attached to the airway channel portion or separate from the airway channel. 
     In accordance with embodiments of the present disclosure, the system can include a dual suction tube having a lower section, an upper section, and a transitional zone between the lower and upper sections. The lower section can include at least one eyelet disposed at a distal end of the lower section. The upper section can include at least one port configured to be connect to a vacuum source. The transitional zone can be disposed between the lower and upper section. The transitional zone can have a first cross-sectional area proximate the proximal end of the transitional zone and a second cross-sectional area proximate to the distal end of the transitional zone, wherein the first cross-sectional area is greater than the second cross-sectional area such that proximal end of the transitional zone is larger than a distal end of the transitional zone. The transitional zone can include at least one eyelet, which can be disposed proximate to the distal end of the transitional zone. 
     The lower section of the dual suction tube can be configured and dimensioned to be inserted in and passed through the gastric-pharyngeal access channel, the upper port connecting the gastric-pharyngeal access channel to the ampulla, the ampulla, and the lower port opposingly spaced from the upper port. The upper section and/or the transitional zone can be configured and dimensioned to be inserted in and passed through the gastric-pharyngeal access channel, the upper port connecting the gastric-pharyngeal access channel to the ampulla, and the ampulla, however, the transitional zone can be configured and dimensioned to engage, or to be inserted in but not to be passed through, the lower port of the ampulla because the distal part of the lower port can be dimensioned to prevent the transitional zone from passing through. The dual suction tube can be configured and/or dimensioned to be inserted into the mask portion via the gastric-pharyngeal channel until the transitional zone engages the lower port of the ampulla and stops the advancement of the dual suction tube. 
     The at least one eyelet disposed near the distal end of the transitional zone can be blocked when the transitional zone is engaged with the lower port of the ampulla. The dual suction tube can include an inner (air) lumen that forms an air vent and a gastric lumen. In some embodiments, the dual suction tube can include a pharyngeal lumen. The gastric lumen extends a length of the dual suction tube. The inner lumen can be disposed within the gastric lumen. 
     In accordance with embodiments of the present disclosure, for embodiments that include the pharyngeal lumen, the pharyngeal lumen can extend from a proximal end of the dual suction tube to the transitional zone. The pharyngeal lumen can include at least one eyelet disposed at a distal end of the pharyngeal lumen which is configured to be positioned in the ampulla when the dual suction tube is inserted into the mask portion. The dual suction tube can have an oval cross-section shape in the upper section that is defined by the gastric lumen and the pharyngeal lumen and can have a circular cross-sectional shape in the lower section defined by the gastric lumen. The pharyngeal lumen has at least one eyelet, which can be disposed in the pharyngeal lumen proximate a distal end of the pharyngeal lumen. The gastric lumen and the pharyngeal lumen can each have a port at the proximal end of the dual suction tube, wherein each port is configured to be connected to a separate vacuum source. 
     In accordance with embodiments of the present disclosure, the dual suction tube can be configured to be withdrawn a specified distance from the mask portion to align the at least one eyelet of the transitional zone with the ampulla to place the eyelet of the transitional zone of the dual suction tube in fluid communication with the ampulla. 
     Other objects and features will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the present disclosure and together with the description, serve to explain the principles of the disclosure. 
         FIGS.  1 A and  1 B  illustrate perspective views of exemplary multi-channel flexible laryngeal mask airway devices having a combined gastric-pharyngeal access channel and a pharyngeal suction channel disposed inside and outside of an airway channel, respectively, according to embodiments of the present disclosure. 
         FIGS.  2 A and  2 B  illustrate perspective views of exemplary multi-channel flexible laryngeal mask airway devices having a pharyngeal suction channel disposed within an airway channel and outside of an airway channel, respectively, according to embodiments of the present disclosure. 
         FIG.  3    illustrates a perspective view of an exemplary multi-channel flexible laryngeal mask airway device according to embodiments of the present disclosure, showing an evacuation system consisting of an ampulla-pharyngeal drains and a combined gastric-pharyngeal access channel integrated within the mask. 
         FIG.  4 A  illustrates a prospective posterior view of a mask portion of an embodiment of the airway devices of  FIGS.  1 A and  1 B  according to embodiments of the present disclosure showing the gastric-pharyngeal access channel and the pharyngeal suction channel embedded in the back of the mask and extending, in parallel with each other, from the ampulla toward the mask-airway channel junction, and the two pharyngeal drains on the back and along the edges of the mask emptying into the ampulla. 
         FIG.  4 B  illustrates a prospective posterior view of a mask portion of an embodiment of the airway devices of  FIGS.  2 A and  2 B  according to embodiments of the present disclosure. 
         FIG.  4 C  illustrates a perspective posterior view of a mask portion of an embodiment of the airway device of  FIG.  3    according to embodiments of the present disclosure. 
         FIG.  5 A  illustrates a perspective posterior view of a mask portion of an embodiment of the multi-channel flexible laryngeal mask airway devices of  FIG.  1 A and  1 B  showing the gastric-pharyngeal access channel and the pharyngeal suction channel embedded in the back of the mask and extending, in parallel with each other, from the ampulla toward the mask-airway channel junction, and the two pharyngeal drains on the back and along the edges of the mask emptying into the ampulla. 
         FIG.  5 B  illustrates a right anterior view of a mask portion of an embodiment of the airway devices of  FIGS.  1 A and  1 B , showing the gastric-pharyngeal access channel and the pharyngeal suction channel traveling in parallel through, and embedded in, the mask, and merging with an ampulla at an apex of the mask portion. 
         FIG.  5 C  illustrates a right anterior view of a mask portion of an embodiment of the airway devices of  FIG.  1 A and  1 B , showing the gastric-pharyngeal access channel and the pharyngeal suction channel entering and passing through the interior space under a dome of the mask before merging with an ampulla at an apex of the mask portion according to embodiments of the present disclosure. 
         FIG.  6 A  illustrates a perspective posterior view of a mask portion of exemplary multi-channel flexible laryngeal mask airway device of  FIG.  3    according to embodiments of the present disclosure showing the gastric-pharyngeal access channel embedded in the back of the mask and extending from the ampulla toward the mask-airway channel junction, and the two pharyngeal drains on the back and along the edges of the mask emptying into the ampulla. 
         FIG.  6 B  illustrates a right anterior view of a mask portion of an embodiment of the airway device of  FIG.  3   , showing the interior space under a dome of the mask with the gastric-pharyngeal access channel embedded within the mask. 
         FIG.  6 C  illustrates a right anterior view of a mask portion of an embodiment of the airway device of  FIG.  3   , showing a gastric-pharyngeal access channel entering and passing through an interior space under a dome of the mask before merging with the ampulla at an apex of the mask portion according to embodiments of the present disclosure. 
         FIG.  7 A  illustrates sagittal view through a spine of a mask portion of an exemplary multi-channel flexible laryngeal mask airway device, showing a gastric-pharyngeal access channel, which originates at the base of the mask, travels along the spine of the mask, and enters an ampulla according to embodiments of the present disclosure. 
         FIG.  7 B  illustrates a sagittal view of a mask portion of an exemplary airway device, showing a gastric-pharyngeal access channel entering a dome of the mask portion, passing through an interior space under the dome before merging with an ampulla at an apex of the mask portion according to embodiments of the present disclosure. 
         FIG.  7 C  illustrates a coronal view, through a top boundary of an ampulla of a mask portion of an exemplary multi-channel flexible laryngeal mask airway device, showing upper ports of the ampulla, with the relation to pharyngeal drains on a back of the mask according to embodiments of the present disclosure. 
         FIG.  8 A  illustrates a perspective view of an exemplary gastric-pharyngeal dual suction tube DST according to embodiments of the present disclosure. 
         FIG.  8 B  illustrates a cross-sectional view of the exemplary DST tube through line  1 - 1  in  FIG.  8 A  according to embodiments of the present disclosure. 
         FIG.  9 A  illustrates a perspective view of another exemplary gastric-pharyngeal dual suction tube DST according to embodiments of the present disclosure. 
         FIG.  9 B  illustrates a cross-sectional view of an upper section of the exemplary DST through line  2 - 2  in  FIG.  9 A  according to embodiments of the present disclosure. 
         FIG.  9 C  illustrates a cross-sectional view of a lower section of the exemplary DST through line  3 - 3  in  FIG.  9 A  according to embodiments of the present disclosure. 
         FIG.  10    illustrates an exemplary ampulla in accordance with embodiments of the present disclosure. 
         FIGS.  11 A and  11 B  illustrate exemplarily a transitional zone of an embodiment of the DST of  FIGS.  8 A-B  and a transitional zone of an embodiment of the DST of  FIGS.  9 A-C , respectively, in accordance with embodiments of the present disclosure. 
         FIGS.  12 A and  12 B  illustrate exemplarily a transitional zone of an embodiment of the DST of  FIGS.  8 A-B  positioned in an ampulla in accordance with embodiments of the present disclosure. 
         FIGS.  13 A and  13 B  illustrate exemplarily a transitional zone of an embodiment of the DST of  FIGS.  9 A-C  positioned in an ampulla in accordance with embodiments of the present disclosure. 
         FIG.  14 A  illustrates an assembled system of an embodiment of the multi-channel flexible laryngeal mask airway device of  FIG.  1 A  with a distal end of an embodiment of the DST of  FIGS.  8 A-B  positioned within an ampulla of the airway device according to embodiments of the present disclosure. 
         FIG.  14 B  illustrates the assembled system of  FIG.  14 A  showing the transition zone of the DST engaging a funnel-shaped distal port of the ampulla, as in  FIG.  12 A , according to embodiments of the present disclosure. 
         FIG.  14 C  illustrates an assembled system of an embodiment of the multi-channel flexible laryngeal mask airway device of  FIG.  3    showing the transition zone of the DST engaging a funnel-shaped distal port of the ampulla, as in  FIG.  13 A , according to embodiments of the present disclosure. 
         FIG.  15    illustrates a perspective view of an exemplary multi-channel flexible laryngeal mask airway device placed in the hypopharynx of a human, and an exemplary dual suction tube placed through a gastric-pharyngeal access channel of the airway device and into the human&#39;s esophagus and stomach with a distal part and gastric eyelets in the stomach while a proximal end extends outside the mouth according to embodiments of the present disclosure. 
         FIG.  16    illustrates a process of forming and using a system that includes an embodiment of the airway device of  FIGS.  1 A,  1 B , or  3 , respectively and an embodiment of the dual suction tube of  FIGS.  8 A-B  or  9 A-C, respectively. 
         FIG.  17    illustrates a process of using a system including the laryngeal mask airway device of  FIGS.  1 A,  1 B , or  3 , respectively, and an embodiment of the gastric-pharyngeal dual suction tube shown in  FIGS.  8 A-B . 
         FIG.  18    illustrates a process of using a system including the laryngeal mask airway device of  FIGS.  1 A,  1 B , or  3 , respectively, and an embodiment of the gastric-pharyngeal dual suction tube shown in  FIGS.  9 A-C   
         FIG.  19 A-H  illustrates various kits that can be formed in accordance with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present disclosure relate to airway devices, systems, and methods that can achieve ventilation of lungs through a mask that seals around the glottis and connects to a flexible airway channel, while also providing evacuation of gastric and/or pharyngeal body fluid and/or blood during upper airway surgeries or procedures. Exemplary embodiments of the present disclosure can improve the safety of airway management and lung ventilation for upper airway surgeries. For example, embodiments of the present disclosure can minimize the risk of aspiration of blood or other fluid accumulated in the pharynx as well as the risk of aspiration of gastric contents during upper airway surgeries. 
       FIGS.  1 A-B  illustrate a perspective view of exemplary multi-channel flexible laryngeal mask airway devices  10  and  10 ′, respectively, according to embodiments of the present disclosure. The airway devices  10  and  10 ′ can include a mask portion  100  and an airway channel portion  200 . The mask portion  100  can define a distal end  12  of the airway devices  10  and  10 ′. The airway channel portion  200  can extend from the mask portion  100  and can have a free terminal end that forms a proximal end  11  of the airway devices  10  and  10 ′. For example, the airway channel portion  200  can extend from the proximal end  11  of the airway devices  10  and  10 ′ to the mask portion  100  and can terminate at a mask-airway channel junction  13  near a base  101  of the mask  110 . 
     The mask portion  100  can include a mask  110  defined as a pear-shaped, dome-like structure having the base  101 , an apex  102 , and a torso  103  disposed between the base  101  and the apex  102 . The mask  110  can be dimensioned and configured to fit within the upper airway of a human to cover and/or seal around the glottis of the human. The dome-like structure of the mask  110  can form a convex surface for a posterior side of the mask  110  which faces towards a posterior pharynx of a human when the mask portion  100  is positioned in the hypopharynx and can form a generally concave surface for an anterior side of the mask  110  which faces towards a larynx or glottis of a human when the mask portion  100  is positioned in the hypopharynx. The mask portion  100  can include a membrane cuff or other cushion material  130  that surrounds a perimeter of the mask  110 . The mask portion  100  can extend along a centerline  104  from a first end defined by the mask-airway channel junction  13  to a second end defined by the distal end  12  of the mask portion  100 . The first or proximal end of the mask portion  100  can be connected to or integrally formed with the airway channel portion  200  and can include an opening that is in fluid communication with an interior volume of an airway channel  210  of the airway channel portion  200  to form the mask-airway channel junction  13 . The first or proximal end of the mask portion  100  can be oriented towards a mouth of a human when the mask portion  100  is positioned in the hypopharynx. The second or distal end of the mask portion, which forms the distal end  12  of the airway device  10  or  10 ′, can be oriented towards an esophagus of a human when the mask portion  100  is positioned within the hypopharynx. In exemplary embodiments, the mask portion  100  can include a pharyngeal suction channel  140 , a gastric-pharyngeal (or gastropharyngeal) access channel  150 , pharyngeal drains  160 , and an ampulla  170  as described herein. The pharyngeal suction channel  140 , the gastric-pharyngeal access channel  150 , the pharyngeal drains  160 , and the ampulla  170  can be formed on and/or embedded within the mask  110 . 
     The airway channel portion  200  extends from the proximal end  11  to the mask-airway channel junction  13  and can include the airway channel  210 . The proximal end  11  of the airway devices  10  and  10 ′ includes an opening  211  to the interior volume of the airway channel  210 . The second or distal end of the airway channel  210  connects to or is integrally formed with the mask  110  of the mask portion  100  at the mask-airway channel junction  13 . The airway channel  210  can be a flexible tubular structure that is reinforced with wires. For example, the airway channel  210  can include an embedded coil wire extending a length of the airway channel  210  such that the airway channel  210  is flexible, but provides resistance to radially inward deformation of the airway channel  210 . In exemplary embodiments, the airway channel  210  can have an internal diameter of approximately 5 millimeters to approximately 11 millimeters or approximately 7 millimeters to approximately 9 millimeters with a length of approximately 18 centimeters to approximately 30 centimeters or approximately 22 centimeters to approximately 26 centimeters for adults. In exemplary embodiments, the airway channel  210  can have an internal diameter of approximately 4 millimeters to approximately 7 millimeters or approximately 4.5 millimeters to approximately 6.5 millimeters with a length of approximately 14 centimeters to approximately 21 centimeters or approximately 15 centimeters to approximately 20 centimeters for children. 
     As shown in  FIGS.  1 A and  1 B , the pharyngeal suction channel  140  can extend from the ampulla  170  towards the proximal end  11  of the airway device  10  or  10 ′. At the mask-airway channel junction  13 , the pharyngeal suction channel  140  can continue upward as a non-rigid pharyngeal suction catheter  141 . As shown in  FIG.  1 A , the pharyngeal suction catheter  141  can be disposed within the interior volume of the airway channel  210  and can terminate as a port formed near the proximal end  11  of the airway device  10 . For example, the pharyngeal suction channel  140  and catheter  141  can terminate as a female luer lock connector  142 , which may be connected to an extension catheter  145 . The pharyngeal suction catheter  141  inside the airway channel  210  exits the airway channel as the female luer lock connector  142  below an airway connector  212  near the proximal end  11  of the airway channel  210 . As shown in  FIG.  1 B , the pharyngeal suction catheter  141  can be disposed outside of and along a length of the flexible airway channel  210  of the airway device  10 ′. The pharyngeal suction catheter  141  in airway device  10 ′ can be attached to the outside of the airway channel  210  or can be free from the airway channel  210 , and terminates as the free female luer lock connector  142 . The female luer lock connector  142  of the airway devices  10  and  10 ′ can be connected to a male luer lock connector  143  of an extension catheter  145  ( FIG.  1 A ) to direct the pharyngeal suction away from the surgical field and close to the anesthetist. The extension catheter  145  can terminate as a three-way port  144  to prevent accidental continuous suction, which may cause injury to the airway mucosa. The pharyngeal suction channel  140  and catheter  141  may be flushed with a syringe through the female luer lock connector  142 . 
     As shown in  FIGS.  1 A and  1 B , in one embodiment, the gastric-pharyngeal access channel  150  can extend along the spine or centerline  104  of the mask  110  from the ampulla  170  to mask-airway channel junction  13 , and the pharyngeal suction channel  140  can be offset to one side of the spine or centerline  104  of the mask  110 . The pharyngeal suction channel  140  and the gastric-pharyngeal access channel  150  extend generally parallel to each other in the mask portion  100  of the airway devices  10  and  10 ′ from the ampulla to the mask-airway channel junction  13  or the pharyngeal suction channel  140  can extend at angle relative to the gastric-pharyngeal access channel such that the pharyngeal suction channel  140  and the gastric-pharyngeal access channel  150  converge at the ampulla and diverge at the mask-airway channel junction  13 . 
     In an exemplary application, the airway device  10  or  10 ′ can be inserted into the upper airway of a human such that the mask portion  100  is positioned in the hypopharynx of the human and the airway channel portion  200  extends from the mask portion such that the free terminal end of the airway channel  210  (i.e., the proximal end  11  of the airway device  10  or  10 ′) is positioned outside of a mouth of the human. When the airway device  10  or  10 ′ is positioned in the upper airway of the human, the airway device  10  or  10 ′ can allow access to the upper airway of the human for surgeries or procedures involving the upper airway. When the airway device  10  or  10 ′ is positioned in the upper airway of the human, the airway device  10  or  10 ′ can facilitate ventilation of lungs through the mask  110  and the flexible thin airway channel  210 , while also providing evacuation of gastric and/or pharyngeal body fluid and/or blood during upper airway surgeries or procedures through two evacuation systems embedded in and integrated with the airway device, that is, through a first evacuation system formed by the gastric-pharyngeal access channel  150 , the pharyngeal drains  160 , and the ampulla  170 , and a second evacuation system formed by the pharyngeal suction channel  140 , the pharyngeal drains  160 , and the ampulla  170 . Therefore, the airway devices  10  and  10 ′ can improve the safety of airway management and lung ventilation for upper airway surgeries, for example, by minimizing the risk of aspiration of blood or other fluid accumulated in the pharynx as well as minimizing the risk of aspiration of gastric contents. 
       FIGS.  2 A and  2 B  illustrate perspective views of an exemplary multi-channel flexible laryngeal mask airway devices  20  and  20 ′, respectively, according to embodiments of the present disclosure. The airway devices  20  and  20 ′ can be substantially similar in structure and function to the airway devices  10  and  10 ′, except for the distinctions noted herein. Therefore, like reference numbers are used to refer to like structures. The airway devices  20  and  20 ′ can include the mask portion  100  and the airway channel portion  200 . The mask portion  100  can include the mask  110 , the pharyngeal suction channel  140 , the pharyngeal drains  160 , and the ampulla  170 . The ampulla  170 , the pharyngeal drains  160  and a portion of a pharyngeal suction channel  140  can be formed on and/or embedded within the mask  110  or mask portion  100 . As shown in  FIGS.  2 A and  2 B , the airway devices  20  and  20 ′ can be devoid of a gastric-pharyngeal access channel  150 . As shown in  FIG.  2 A , the pharyngeal suction catheter  141  can be disposed within the interior volume of the airway channel  210  and can terminate and exit the airway channel  210  as the female luer lock connector  142  below an airway connector  212  near the proximal end  11  of the airway channel  210 . As shown in  FIG.  2 B , the pharyngeal suction catheter  141  can be disposed outside of and along a length of the flexible airway channel  210  of the airway device  20 ′. The pharyngeal suction catheter  141  in airway device  20 ′ can be attached to the outside of the airway channel  210  or can be free from the airway channel  210 , and terminates as the free female luer lock connector  142 . The female luer lock connector  142  of the airway devices  20  and  20 ′ can be connected to a male luer lock connector  143  of an extension catheter  145  ( FIG.  2 A ) as described herein. Like airway devices  10  and  10 ′, the mask portion  100  of the airway devices  20  and  20 ′ can cover and seal around the glottis and the flexible airway channel portion  200  of the airway devices  20  and  20 ′ can extend from the mask portion  100  to the outside of the mouth when the airway device  20  or  20 ′ is positioned in the upper airway of a human. 
     In an exemplary application, referring to  FIGS.  2 A and  2 B , the airway device  20  or  20 ′ can be inserted into the upper airway of a human such that the mask portion  100  is positioned in the hypopharynx of the human and the airway channel portion  200  extends from the mask portion such that the free terminal end of the airway channel  210  (i.e., the proximal end  11  of the airway device) and the port (luer lock connector)  142  of the pharyngeal suction channel  140  are positioned outside of a mouth of the human. When the airway device  20  or  20 ′ is positioned in the upper airway of the human, the airway device  20  or  20 ′ can allow access to the upper airway of the human for surgeries or procedures involving the upper airway. The airway device  20  or  20 ′ can facilitate ventilation of lungs through the mask  110  and the flexible thin airway channel  210 , while also providing evacuation of gastric and/or pharyngeal body fluid and/or blood during upper airway surgeries or procedures through a drainage and evacuation system formed by the pharyngeal suction channel  140 , the pharyngeal drains  160 , and the ampulla  170 . Therefore, the airway device  20  or  20 ′ can improve the safety of airway management and lung ventilation for upper airway surgeries, for example, by minimizing the risk of aspiration of blood or other fluid accumulated in the pharynx and possibly minimizing the risk of aspiration of gastric contents. 
       FIG.  3    illustrates a perspective view of an exemplary multi-channel flexible laryngeal mask airway device  30 , according to embodiments of the present disclosure. The airway device  30  can be substantially similar in structure and function to the airway device  10 , except for the distinctions noted herein. Therefore, like reference numbers are used to refer to like structures. The airway device  30  can include the mask portion  100  and the airway channel portion  200 . The mask portion  100  can include the mask  110 , the gastric-pharyngeal access channel  150 , the pharyngeal drains  160 , and the ampulla  170 . As shown in  FIG.  3   , the airway device  30  can be devoid of the pharyngeal suction channel and the pharyngeal suction catheter. The gastric-pharyngeal access channel  150 , the pharyngeal drains  160 , and the ampulla  170  can be formed on and/or embedded within the mask  110  or mask portion  100 . Like airway device  10 , the mask portion  100  of the airway device  30  can covers and seals around the glottis and the flexible airway channel portion  200  can extend from the mask portion  100  to the outside of the mouth when the airway device  30  is positioned in the upper airway of a human. 
     In an exemplary application, referring to  FIG.  3   , the airway device  30  can be inserted into the upper airway of a human such that the mask portion  100  is positioned in the hypopharynx of the human and the airway channel portion  200  extends from the mask portion  100  such that the free terminal end of the airway channel  210  (i.e., the proximal end  11  of the airway device) is positioned outside of a mouth of the human. When the airway device  30  is positioned in the upper airway of the human, the airway device  30  can allow access to the upper airway of the human for surgeries or procedures involving the upper airway. When the airway device  30  is positioned in the upper airway of the human, the airway device  30  can facilitate ventilation of lungs through the mask  110  and the flexible thin airway channel  210 , while also providing evacuation of gastric and/or pharyngeal body fluid and/or blood during upper airway surgeries or procedures through an evacuation system embedded in and integrated with the airway device, that is, through an evacuation system formed by the gastric-pharyngeal access channel  150 , the pharyngeal drains  160 , and the ampulla  170 . Therefore, the airway device  30  can improve the safety of airway management and lung ventilation for upper airway surgeries, for example, by minimizing the risk of aspiration of blood or other fluid accumulated in the pharynx as well as minimizing the risk of aspiration of gastric contents. 
       FIGS.  4 A and  5 A -C illustrate the mask portion of the airway devices  10  and  10 ′ of  FIGS.  1 A and  1 B  in more detail.  FIG.  4 B  illustrates the mask portion of the airway devices  20  and  20 ′ of  FIGS.  2 A and  2 B  in more detail.  FIGS.  4 C and  6 A -C illustrates the mask portion of the airway devices  30  of  FIG.  3    in more detail. As described herein, the mask portion of the airway device  20  and  20 ′ is devoid of the gastric-pharyngeal access channel and the mask portion of the airway device  30  is devoid of the pharyngeal suction channel. The mask  110  can have a pear-shaped dome structure with an angulated and elongated opening  111  on the back side of the mask  110  at the first or proximal end (e.g., a top of the mask toward the base or upper part of the mask) where the airway channel  210  interfaces with the mask  110  at the junction  13  and is in fluid communication with an interior space  180  defined by the front side of the mask under the dome of the mask. The mask  110  may be made of materials such as PVC, silicone or styrene ethylene butadiene styrene that are firm enough to maintain the shape of the dome and the angle of the opening  111 . The mask  110  can be surrounded by a soft edge such as the inflatable membrane cuff or other cushion materials  130 , which can form or create a seal around the glottis of a human. The soft edge of the cuff or cushion  130  can be formed from one or more materials and by one or more methods of construction. If a membrane cuff is used, the cuff can be inflated either through tubing or automatically through the airway channel during positive pressure ventilation. With the soft edge of the cuff or cushion  130 , the mask  110  covers and seals around the glottis when placed properly in the hypopharynx. 
     The apex  102  (e.g., proximate to the second end or lower part defined at the distal end  12 ) of the mask  110  encloses the ampulla  170 , which includes ports  171 - 175 . The ampulla can be an enclosed chamber or cavity accessible via the ports  171 - 175  which can form openings to the interior volume of the ampulla  170 . The ampulla can have a generally bulbous or spherical internal volume. For embodiments of the mask portion that do not include the gastric-pharyngeal access channel  150 , the ampulla  170  can be devoid of the port  175 , as shown in  FIG.  4 B . For embodiments of the mask portion that do not include the pharyngeal suction channel  140 , the ampulla  170  can be devoid of the port  174 , as shown in  FIGS.  4 C and  6 A -C. The port  175  forms an upper port of the ampulla  170  and connects the ampulla  170  to the gastric-pharyngeal access channel  150  such that the ampulla  170  and the gastric-pharyngeal access channel  150  can be in fluid communication with each other. The port  171  forms a distal or lower port of the ampulla  170  and opens to the upper esophagus when the mask portion  100  is positioned in the hypopharynx of a human. The ports  171  and  175  can be opposingly spaced and aligned with each other. The ports  172  and  173  of the ampulla  170  can be formed on opposing sides of the ampulla (i.e. one on each side of the ports  171  and  175 ). The ports  172  and  173  can be offset from the port  175  towards the distal end  12  of the mask portion  100  and can open towards the port  171 . The port  174  of the ampulla  170  can be disposed adjacent to the port  175  between the port  175  and the port  172  (or port  173 ). 
     The pharyngeal suction channel  140  can be formed on or integrated with the mask  110 , and can extend from the upper port  174  of the ampulla to the base  101  of the mask. The pharyngeal suction channel  140  can be embedded within the back of the mask and travel along the spine of the mask ( FIG.  5 B ) or can be formed and travel in the dome beneath the back of the mask ( FIG.  5 C ). At the mask-airway channel junction  13 , the pharyngeal suction channel  140  continues as a non-rigid catheter  141  inside or outside of the airway channel  210 . The pharyngeal suction channel  140  is configured and dimensioned to allow for effective suction and evacuation of fluid or blood collected in the ampulla  170  via the pharyngeal drains  160 . 
     The gastric-pharyngeal access channel or gastropharyngeal channel  150  can be formed on or embedded in and integrated with the mask  110 , and can extend from an opening  151  on the back of the mask, proximate to the first or proximal end (e.g. near the base  101 ) of the mask portion, to the upper port  175  of the ampulla  170  in the apex  102  of the mask  110 . The gastric-pharyngeal access channel  150  can travel along the spine of the mask and enter the ampulla  170  at the upper port  175  to face the lower or distal port  171 , which opens to the upper esophagus when the airway device is properly positioned in the hypopharynx of a human. In one embodiment, the gastric-pharyngeal access channel  150  itself (as shown in  FIG.  6 B ) or along with the pharyngeal suction channel  140  (as shown in  FIG.  5 B ) can be embedded in the mask  110 , where the gastric-pharyngeal access channel  150  extends along the center line of the mask  110  to form part of a spine of the mask  110 . In another embodiment, the gastric-pharyngeal access channel  150  itself (as shown in  FIG.  6 C ) or along with the pharyngeal suction channel  140  (as shown in  FIG.  5 C ) can penetrate the back of the mask  110  to the front side of the mask, entering and passing through the interior volume  180  under a dome of the mask  110  before merging with the ampulla  170  via the upper ports  174  and  175 , respectively. In some embodiments, one of the pharyngeal suction channel  140  and the gastric-pharyngeal access channel  150  can be embedded in the mask  110 , and the other one can pass through the interior volume  180  under the dome of mask  110  before merging with the ampulla  170 . 
     The gastric-pharyngeal access channel  150  can be configured and dimensioned to receive a gastric suction tube or gastric-pharyngeal dual suction tube (DST) as described herein. For example, a cross-sectional area of the gastric-pharyngeal access channel  150  can be configured and dimensioned to allow for the passage of an appropriately sized gastric suction tube or gastric-pharyngeal dual suction tube DST (e.g. a size 12-18F for an adult). As an example, to accommodate a size 12-18F tube, the cross-sectional dimensions of the combined gastric-pharyngeal access channel  150  can be approximately five (5) millimeters by approximate eight (8) millimeters. In exemplary embodiments, the gastric-pharyngeal access channel can have generally oval cross-sectional shape. 
     A ramp  152  can be formed on the back of the mask from mask-airway channel junction  13  to the opening  151  of the gastric-pharyngeal access channel  150 . The ramp  152  provides a guide for entry to the proximal opening  151  of the gastric-pharyngeal access channel  150 . The ramp can be as a shallow recess formed in the back of the mask at the base  101  of the mask. The depth of the recess can gradually increase towards the opening  151  until the ramp  152  reaches the opening  151  at which point the depth of the recess of the ramp  152  can generally correspond to a depth of a bottom portion of the opening  151 . 
     The pharyngeal drains  160  can be formed on or in the back of the mask  110 . The pharyngeal drains  160  can extend along the side edges of the mask  110  from base  101  of the mask  110  towards the apex  102  of the mask  110 . For example, the pharyngeal drains  160  can originate at the top of the mask  110 , on the sidewalls of the mask  110  near the airway channel-mask junction  13  as small and shallow grooves or recesses. The pharyngeal drains  160  can gradually increase in width and depth before merging into the side ports  172  and  173  of the ampulla  170  near the apex  102  of the mask to form an ampulla-pharyngeal drain system. When the mask portion is positioned in the hypopharynx to cover and/or seal around the glottis, pharyngeal body fluid and/or blood can be collected by pharyngeal drains  160  during upper airway surgeries or procedures and can flow into the ampulla  170  where it can be removed through the pharyngeal suction channel  140  or using a suction tube via the gastric-pharyngeal access channel  150  as described herein. The high origination of the pharyngeal drains  160  provides air entry to the ampulla-pharyngeal drain system during suction, thereby preventing vacuum injury to the pharyngeal mucosa. 
       FIGS.  7 A-B  illustrate sagittal cross-sectional views, cut through the spine or centerline of the mask portion  100  in accordance with embodiments of the present disclosure. As shown in  FIG.  7 A , in one embodiment, the gastric-pharyngeal access channel  150 , which originates proximate to the mask-airway channel junction  13 , travels along the spine of the mask, and enters the ampulla  170  at port  175  facing the distal port  171  of the ampulla. The gastric-pharyngeal access channel  150  can be contained within the mask portion bounded by mask-airway channel junction  13  and the distal end  12  (i.e., the ends of the gastric-pharyngeal access channel can terminate within the mask portion). The opening  151  can open to the atmosphere or surrounding environment. The gastric-pharyngeal access channel  150  originates with the opening  151  at the first end or the base  101  of the mask. The ramp  152  slopes towards the opening  151  to provide a guide for inserting a tube, such as a suction tube, into the combined gastric-pharyngeal access channel  150 . As shown in  FIG.  7 B , in another embodiment, the gastric-pharyngeal access channel  150  can enter the dome of the mask, passing through the interior volume  180  under the dome, and merge with the ampulla  170  at port  175 . For embodiments that include both the gastric-pharyngeal access channel  150  and the pharyngeal suction channel  140  (e.g., the airway devices  10  and  10 ′ shown in  FIGS.  1 A-B ), the pharyngeal suction channel  140  can travel generally parallel to and along with the gastric-pharyngeal access channel in the mask portion  100  and can be embedded in the mask or attached underneath the mask, as described herein. 
       FIG.  7 C  illustrates a coronal cross-section view of the mask portion cut through the upper edge of the ampulla  170  of the airway device  10  or  10 ′ shown in  FIGS.  1 A and  1 B . The coronal cross-section view shows the upper port  175  to the gastric-pharyngeal access channel  150  and the upper port  174  to the pharyngeal suction channel  140  in relation to the pharyngeal drains  160  on the back of the mask. The port  175  can be larger in diameter than the port  174 , and the port  174  can be offset to one side of the mask  110 . The port  175  can be generally aligned with a center line of the mask  110 . For embodiments that do not include the pharyngeal suction channel  140  (e.g., the airway device  30  shown in  FIG.  3   ), the ampulla  170  does not include the port  174  and for embodiments that do not include the gastric-pharyngeal access channel (e.g., airway devices  20  and  20 ′ shown in  FIG.  2 A and  2 B ), the ampulla  170  does not include the port  175 . As shown in  FIG.  7 C , the pharyngeal drains  160  can be formed as recesses in the back of the mask  110  near, but inward of, the edge or perimeter of the mask  110 . 
       FIG.  10    shows a detailed view of the ampulla of embodiments of the present disclosure and a configuration of the port  171 . In exemplary embodiments, as shown in  FIG.  10   , the distal port  171  can be approximately five millimeters to approximately eighteen millimeters or approximately eight millimeters to approximately fifteen millimeters in length (L). The distal port  171  can have a funnel-like shape such that the distal port  171  tapers inwardly as it extends from the ampulla  171  to the distal end  12  of the airway device such that a cross-sectional area of the distal port gradually decreases as the distal port extends towards the distal end  12  from the ampulla  170 . As an example, as shown in  FIG.  10   , a cross-section of an end of the distal port proximate to the ampulla (e.g., an upper end of the distal port  171 ) can have dimensions (W 1 ) of approximately five (5) millimeters by approximately six (6) millimeters and a cross-section of an end of the distal port proximate to the distal end  12  of the airway device (e.g., a lower end of the distal port) can have dimensions (W 2 ) of approximately four and five tenths (4.5) millimeters by approximately four and five tenths (4.5) millimeters. 
     In some embodiments, the ampulla  170  can include a distal valve  176  covering the distal opening of the port  171  ( FIG.  10    insertion). In some embodiments, the ampulla is devoid of the valve  176 . In it closed or normal state, the distal valve can be a tri-leaflet membrane that has a center hole  178 , which can be approximately one millimeter (1 mm) in diameter, and each leaflet  177  of the tri-leaflet configuration can engage and/or overlap adjacent leaflets. In the closed or normal state, the leaflets  177  can extend radially inwardly towards the center hole. The leaflets  177  can be hinged along a perimeter of the distal end of the port  171  to facilitate rotation or deformation of the leaflets  177  outwardly away from the distal end of the port (e.g., upon introduction of a DST) to an open state and to facilitate rotation of the leaflets  177  inwardly towards the distal end of the port  171  back to the closed state absent any structure or force holding the valve in the open state. In its closed state, the tri-leaflet distal valve  176  can function to block or retard fluid drainage from the ampulla  170  into the esophagus, e.g., when there is no DST inserted through the distal port  171 , while allowing air vent out of the esophagus or stomach, which prevents air insufflation of the stomach due to air leaking from the airway through the laryngeal mask airway device during positive pressure ventilation. As an example, in the closed state, the tri-leaflets valve  176  can sustain a pressure of 5 cmH2O from the fluid accumulated in the ampulla  170  but can allow for venting of air or fluid with pressure high than 5 cmH2O from the esophagus or stomach or with vacuum applied to the ampulla. The tri-leaflets valve  176  allows for passage of an appropriately-sized gastric suction tube to access the esophagus and/or stomach. The two side ports  172  and  173  of the ampulla  170  can be connected to and in fluid communication with the pharyngeal drains  160  on or in the mask. 
       FIGS.  8 A-B  and  9 A-C illustrate perspective views of an exemplary gastric-pharyngeal dual suction tube (DST)  400  and  500 , respectively, in accordance with embodiments of the present disclosure. The DSTs  400  and  500  can be formed of PVC or similar materials with suitable firmness for insertion into and through the gastric-pharyngeal access channel  150  of embodiments of the airway device  10 ,  10 ′ or  30 . 
     As shown in  FIG.  8 A , the DST  400  includes a lower or gastric section  401 , an upper or pharyngeal section  402 , and a transitional zone  403  connecting the lower and upper sections  401  and  402 . The lower section  401  can include gastric eyelets or openings  411  and the transitional zone  403  can include pharyngeal eyelets or openings  412 . The transitional zone  403  can serve as a distal portion of the upper section  402 . 
     The DST  400  can include two lumens: the main or suction lumen  410  and the air lumen  420 . The main lumen  410  is larger than the air lumen  420  and is the working lumen for suction and evacuation of bodily fluids. The proximal end of the main lumen  410  terminates as a three-way port  413 , which allows for vacuum suction only through hand regulation and avoids continuous suction which may cause injury to the gastric mucosa. The air lumen  420  provides an air vent, which allows for atmospheric air to enter the tube through a proximal port  421  and equalize the vacuum pressure once the contents are removed, preventing vacuum injury to the mucosa. 
     The lower (gastric) section  401  can be configured and dimensioned to fit and pass through the gastric-pharyngeal access channel  150  as well as the funnel-shaped distal port  171  of the ampulla  170  of the airway devices  10 ,  10 ′, and  30 . For embodiments in which the distal port  171  includes the tri-leaflet valve  176 , the lower section  401  can be configured and dimensioned to fit and pass through the tri-leaflet valve  176  to urge the tri-leaflet valve  176  to transition from its closed position to its open position. In exemplary embodiments, the lower section  401  can be approximately thirty-eight (38) centimeters to approximately forty-two (42) centimeters in length or approximately forty (40) centimeters in length. When the lower section  401  is positioned properly in the airway device  10  or  10 ′ or  30  that is placed in the hypopharynx of a human, approximately fifteen (15) centimeters of the lower section  401  can be left in the stomach of an adult human. 
     The upper (pharyngeal) section  402  and the transitional zone  403  can be configured and dimensioned to fit and pass through the gastric-pharyngeal access channel  150 . However, as shown in  FIG.  11 A  and referring to  FIGS.  10  and  12 A , the transitional zone  403  is configured and dimensioned to be too large to pass through the distal port  171  of the ampulla  170 . As a result, the distal port  171  forms a stop structure such that the DST  400  is fully inserted when the transitional zone  403  abuts the distal port  171  of the ampulla. The upper section and the transitional zone combined are approximately thirty-three (33) centimeters to approximately thirty-eight (38) centimeters or approximately thirty-five (35) centimeters in length, such that when the transition zone  403  abuts the distal port  171  positioned in the upper airway of a human, approximately fifteen (15) centimeters of the DST  400  is outside the mouth in an adult ( FIG.  15   ). 
     Referring to  FIGS.  8 A and  11 A , the transitional zone  403  can have a generally truncated cone-shaped structure. The lower section  401  and the upper section  402  can have a first generally uniform cross-sectional area (A 1 ) along their lengths, although the lower section  401  can taper slightly at the distal end ( FIG.  8 A ). At a transition between the upper section  402  and the transitional zone  403 , the cross-sectional area of the DST  400  increases to a second cross-sectional area (A 2 ), which is greater than the first cross-sectional area, and then the cross-sectional area gradually decreases to return to the first cross-sectional area (A 1 ) at the transition from the transitional zone  403  to the lower section  401  ( FIG.  11 A ). The transitional zone  403  can have a length (L T ) of approximately eight (8) millimeters to approximately twelve (12) millimeters or approximately ten (10) millimeters. The distal end of the transitional zone  403  (i.e., the transition from the transitional zone  403  to the lower section  401 ) can have dimensions (W T1 ) of approximately four millimeters by approximately four millimeters (4×4 mm), which fits through the gastric-pharyngeal access channel  150  having a dimension (W) of up to approximately five by approximately eight millimeters (5×8 mm), and can enter the distal port  171  of the ampulla  170 , which has dimensions of approximately five by approximately six millimeters (5×6 mm) at the top (W 1 ) and approximately four and five tenths by approximately four and five tenths (4.5×4.5 mm) at the bottom (W 2 ), respectively ( FIG.  10   ). However, the proximal or top end of the transitional zone  403  (i.e., the transition from the upper section  402  to the transitional zone  403 ) can have dimensions (W T2 ) of approximately four millimeters by six and six tenths millimeters (4×6.6 mm), and thus cannot pass through the funnel-shaped distal port  171  of the ampulla, which has dimensions (W 1 ) of five by six millimeters (5×6 mm) at the top ( FIG.  10   ). Therefore, the transitional zone  403  serves as a functional separation of the gastric suction and the pharyngeal suction, and as a guide to the depth of insertion of the DST  400  into embodiments of the airway device  10 , or  30  or  30 ′, and into the stomach. 
     As described herein, the DST  400  can have two sets of suction eyelets: the gastric eyelets  411  and the pharyngeal eyelets  412 . The first set or gastric eyelets  411  are located at the distal end of the tube, approximately  40  cm from the transitional zone  403 , and are used for evacuating fluids from the stomach. The second set or pharyngeal eyelets  412  are located in the truncated cone-shaped transitional zone  403 , about  35  cm from the proximal end, and are used for evacuating fluids from the pharynx through the ampulla-pharyngeal drains. As shown in  FIGS.  8 A and  11 A , the pharyngeal eyelets  412  can be disposed proximate to the distal end of the transitional zone  403  (i.e., proximate to the transition from the transitional zone  403  to the lower section  401 ). 
     With reference to  FIGS.  1 A-B ,  3 ,  8 A, and  12 A-B, the DST  400  can be used with an airway device that has a gastric-pharyngeal access channel  150  with or without a pharyngeal suction channel  140  (e.g., airway devices  10 ,  10 ′, or  30  shown in  FIGS.  1 A,  1 B, and  3   ). The DST  400  can be placed through the gastric-pharyngeal access channel via the proximal opening  151  located near the mask-airway channel junction  13 . The lower section  401  can pass through the oval-shaped gastric-pharyngeal access channel  150  and the funnel-shaped distal port  171  of the ampulla  170 , entering the esophagus and the stomach, until the cone-shaped transitional zone  403  reaches the funnel-shaped distal port  171  of the ampulla  170  where the DST  400  is prevented from being inserted further ( FIGS.  12 A and  14 B ). That is, the DST  400  can be configured and/or dimensioned to be inserted into the mask portion via the gastric-pharyngeal channel until the transitional zone engages the distal port  171  of the ampulla, which is configured and dimensioned to engage and stop the advancement of the dual suction tube  400 . At this position, the gastric eyelets  411  are positioned in the stomach approximately  15  cm below the gastro-esophageal junction, while the pharyngeal eyelets  412  are blocked in the funnel-shaped distal port  171  of the ampulla and are not functional ( FIGS.  12 A and  14 B ). If access to the ampulla-pharyngeal drain system through the DST is needed, the DST  400  can be withdrawn about 5 to 8 mm to position the pharyngeal eyelets  412  in the ampulla  170  so they are no longer blocked by the distal port  171  ( FIG.  12 B ). Mark lines  450  on the upper part of the dual suction tube  400  ( FIG.  8 A ) can guide the withdrawal. 
     While  FIG.  8 A  shows two sets of eyelets, embodiments of the DST  400  may include more or less sets of eyelets. For example, in one embodiment, the DST  400  can be devoid of the pharyngeal eyelets  412  so that the suction tube is a gastric suction tube without pharyngeal suction capability, while the transitional zone can still guide the depth of insertion. 
       FIG.  8 B  is a cross-sectional view of the DST  400  shown in  FIG.  8 A . As shown in  FIG.  8 B , the DST  400  can have a generally circular cross-sectional shape in the lower and upper sections  401  and  402 . The air lumen  420  can be disposed within the DST  400 . 
     As shown in  FIG.  9 A-C , the DST  500  includes three sections: a lower gastric section  501 , an upper pharyngeal section  502 , and a transitional section  503 , which connects the lower and upper sections  501  and  502 . The DST  500  can include three lumens: a gastric lumen  510 , an air lumen  520 , and a pharyngeal lumen  530 . 
     The gastric lumen  510  can be the first and largest lumen, and is the working lumen for suction and evacuation of fluids from the stomach. The air lumen  520  can be the second and smallest lumen. Similar to air lumen  420  in DST  400 , the air lumen  520  is for air vent—it travels along the gastric lumen and allows for atmospheric air to enter the stomach through a proximal port  521  and equalize the vacuum pressure once the gastric contents are removed, preventing vacuum injury to the mucosa. The pharyngeal lumen  530  can be the third lumen, and is the working lumen for suction and evacuation of fluids from the ampulla-pharyngeal drains. The pharyngeal lumen  530  has a length that extends from the proximal end of DST  500  to about the transitional zone  503 . The pharyngeal lumen  530  can be terminated before reaching the transitional zone  503  ( FIGS.  9 A and  13 A,  13 B . The proximal ends of the two large lumens  510  and  530  each terminate as a three-way port  513  and  533 , respectively, which can allow for vacuum suction only through hand regulation and avoids continuous suction that may cause injury to the mucosa. 
     The lower (gastric) section  501  can have a circular cross-section that is configured and dimensioned to fit and pass through the gastric-pharyngeal access channel  150  as well as the funnel-shaped distal port  171  of the ampulla. As an example, the lower section  501  can have diameter of approximately four (4) millimeters ( FIG.  9 C ), and a length of approximately thirty-eight (38) centimeters to approximately forty-two (42) centimeters or can be approximately 40 cm in length. The lower section  501  can be dimensioned and configured to pass through the esophagus, leaving approximately  15  cm in the stomach in an adult, when the DST  500  is fully received in the airway device  10 , or  10 ′ or  30  positioned in the upper airway of a human. 
     Referring to  FIGS.  9 A-C , the upper (pharyngeal) section  502  and transition zone  503  can be configured and dimensioned to fit and pass through the gastric-pharyngeal access channel, but to be too large to pass through the funnel-shaped distal port  171  of the ampulla. The upper section  502  can have a length of approximately thirty-three (33) centimeters to approximately thirty-eight (38) centimeters or can be approximately thirty-five (35) centimeters in length, which, when positioned properly, leaves approximately fifteen (15) cm outside of the mouth in an adult. 
     As shown in  FIGS.  9 A and  11 B , the lower section  501  can have a first generally uniform cross-sectional area (A 1 ) along its length, although the lower section  501  can taper slightly at the distal end. The upper section  502  can have a second generally uniform cross-sectional area (A 2 ) along its length. At a transition between the upper section  502  and the transitional zone  503 , the cross-sectional area can be approximately the same of the second cross-sectional area (A 2 ), which is greater than the first cross-sectional area, and then the cross-sectional area of the transitional zone  503  gradually decreases to the first cross-sectional area (A 1 ) at the transition from the transitional zone  503  to the lower section  501  ( FIG.  11 B ). As a result, the transitional zone  503  can have a generally truncated cone-shaped structure. Similar to the transitional zone  403  in the DST  400  and as shown in  FIG.  11   , the transitional zone  503  can have a dimension and configuration that can enter but cannot pass through the distal port  171  of the ampulla, that is, the diameter (W T2 ) of the upper section  502  or the top of the transitional zone  503  is too large to fit the upper diameter (W 1 ) of the distal port  171 . The transitional zone  503  of DST  500  provides a structural separation of the gastric suction and the pharyngeal suction such that two separated lumens can function simultaneously. In addition, the transitional zone ensures correct placement and position of the DST  500 . 
     Referring to  FIGS.  9 A and  11 B , the DST  500  has three sets of suction eyelets. The first set is the distal or gastric eyelets  511  of the gastric lumen, which are located at the distal end of the DST  500 , approximately  40  cm from the transitional zone  503 , and are used for evacuating fluids from the stomach. The second set is the proximal or pharyngeal eyelets  512  of the gastric lumen. The pharyngeal eyelets  512  are located in the truncated cone-shaped transitional zone  503  proximate to the transition between the transitional zone  503  and the lower section  501 . The third set, absent in DST 400 , is the pharyngeal eyelets  531  of the pharyngeal lumen  530 , which are located immediately above the truncated cone-shaped transitional zone  503 , about 35 cm from the proximal end, and are used for evacuating the pharynx through the ampulla-pharyngeal drains. In some embodiments, the second set of eyelets  512  can be omitted as the second set of eyelets can operate only as a back-up system for the third set of eyelets  531 , for evacuating the pharynx through the ampulla-pharyngeal drains. 
     With reference to  FIGS.  1 A-B ,  3 ,  9 A, and  13 A-B, the DST  500  can be used with an airway mask that has a gastric-pharyngeal access channel  150  with or without the pharyngeal suction channel  140 . For embodiments (e.g. airway device  30  shown in  FIG.  3   ) devoid of the pharyngeal suction channel  140 , the ampulla-pharyngeal drains can only be accessed through the gastric-pharyngeal access channel  150 . The DST  500  can be placed through the gastric-pharyngeal access channel via the proximal opening  151  located near the mask-airway channel junction  13 . The lower section  501  can pass through the oval-shaped gastric-pharyngeal access channel  150  and the funnel-shaped distal port  171  of the ampulla, entering the stomach via the esophagus, until the cone-shaped transitional zone  503  reaches the funnel-shaped distal port  171  of the ampulla where the DST is prevented from being further inserted ( FIGS.  13 A and  14 C ). That is, the DST  500  can be configured and/or dimensioned to be inserted into the mask portion via the gastric-pharyngeal channel until the transitional zone engages the distal port  171  of the ampulla, which is configured and dimensioned to engage and stop the advancement of the dual suction tube  500 . At this position, the distal gastric eyelets  511  are positioned in the stomach approximately 15 cm below the gastro-esophageal junction, while the pharyngeal eyelets  531  of the pharyngeal lumen are positioned above the funnel-shaped distal port inside the ampulla  170  ( FIGS.  13 A and  14 C ). For embodiments of DST  500  that include the proximal eyelets  512  of the gastric lumen, in this position, the proximal eyelets  512  of the gastric lumen are blocked in the funnel-shaped distal port  171  of the ampulla ( FIG.  13 A ). Suction of the stomach is achieved if the vacuum is connected to the proximal port  513  of gastric lumen  510 , while suction of the ampulla-pharyngeal drains is achieved if vacuum is applied to the proximal port  533  of the pharyngeal lumen  530 . If the pharyngeal eyelets  531  are clogged, the DST  500  may be pulled back by 5 to 8 mm to position the proximal eyelets  512  of the gastric lumen in the ampulla for evacuation of the ampulla-pharyngeal drains ( FIG.  13 B ). 
       FIG.  9 B  is a cross-sectional view of the upper section  502  of the DST  500  shown in  FIG.  9 A . As shown in  FIG.  9 B , DST  500  includes three lumens: the gastric lumen  510 ; the air lumen  520 ; and the pharyngeal lumen  530 . The DST  500  can have a generally oval or elliptical cross-sectional shape defined by the gastric lumen  510  and the pharyngeal lumen  530 , where the cross-sectional area of the gastric lumen  510  is larger than the cross-sectional area of the pharyngeal lumen  530 . The adjacent sides of the gastric lumen  510  and the pharyngeal lumen  530  can be generally planer or linear, but can be reversible deformed during use. The air lumen  520  can be disposed within the gastric lumen  510  and can have a circular cross-section shape. 
       FIG.  9 C  is a cross-sectional view of the lower section  501  of the DST  500  shown in  FIG.  9 A . As shown in  FIG.  9 C , the lower section  501  in DST  500  can have a generally circular cross-sectional shape defined by the gastric lumen  510 , which can have a generally tubular structure. The air lumen  520  can be disposed within the gastric lumen  510  and can have a circular cross-section shape. 
       FIGS.  14 A-B  illustrate an assembly of a multi-channel flexible laryngeal mask airway device system including an embodiment of the airway device  10  of  FIG.  1 A  with an embodiment of the DST  400  of  FIG.  8 A-B . While  FIGS.  14 A-B  illustrate a system including the airway device  10  and the DST  400 , exemplary embodiments of systems in accordance with the present disclosure can be formed using any one of the airway devices  10 ,  10 ′, or  30  with anyone of the DST  400  or  500  described herein. In  FIG.  14 A , the DST  400  is placed inside the gastric-pharyngeal access channel  150  through the proximal opening  151  (guided by the ramp  152 ) with a tip of DST  400  (i.e., the distal end) positioned in the ampulla  170 . The DST  400  is advanced through the gastric-pharyngeal access channel and the lower section  401  passes through the funnel-shaped distal port  171  of the ampulla  170 , and in  FIG.  14 B , the DST  400  is inserted further through the gastric-pharyngeal access channel  150  until the cone-shaped transitional zone  403  engages the funnel-shaped distal port  171  of the ampulla ( FIG.  12 A ). In this position, suction through the gastric eyelets  411  can be achieved, while the pharyngeal eyelets  412  are blocked by the sidewall of the distal port  171  and are non-functional ( FIG.  12 A ). The DST  400  can be pulled back towards the proximal end to position the pharyngeal eyelets  412  in the ampulla so that the pharyngeal eyelets are no longer blocked by the distal port  171  ( FIG.  12 B ). At this point, suction through the pharyngeal eyelets  412  can be achieved to evacuate the ampulla and pharyngeal drains  160 . 
       FIG.  14 C  illustrates an assembly of a multi-channel flexible laryngeal mask airway device system including an embodiment of the airway device  30  of  FIG.  3    with an embodiment of the DST  500  of  FIG.  9 A-C . While  FIG.  14 C  illustrates a system including the airway device  30  and the DST  500 , exemplary embodiments of systems in accordance with the present disclosure can be formed using any one of the airway devices  10 ,  10 ′, or  30  with anyone of the DST  400  or  500  described herein. In  FIG.  14 C , the DST  500  is placed inside the gastric-pharyngeal access channel  150  through the proximal opening  151  (guided by the ramp  152 ) with a tip of DST  500  (i.e., the distal end) positioned in the ampulla  170  ( FIGS.  13 A and  14 C ). The DST  500  is advanced through the gastric-pharyngeal access channel and the lower section  501  passes through the funnel-shaped distal port  171  of the ampulla  170 . The DST  500  is inserted further through the gastric-pharyngeal access channel  150  until the cone-shaped transitional zone  503  engages the funnel-shaped distal port  171  of the ampulla  170  ( FIGS.  13 A and  14 C ). In this position, suction through the gastric eyelets  511  can be achieved and suction through the pharyngeal eyelets  531  can be achieved, while the pharyngeal eyelets  512  are blocked by the sidewall of the distal port  171  and are non-functional ( FIG.  13 A ). The DST  500  can be pulled back towards the proximal end to position the pharyngeal eyelets  412  in the ampulla so that the pharyngeal eyelets  512  are no longer blocked by the distal port  171  ( FIG.  13 B ). At this point, suction through the pharyngeal eyelets  512  can be achieved to evacuate the ampulla and pharyngeal drains  160 . 
       FIG.  15    illustrates, according to the present disclosure, a perspective view of an exemplary multi-channel flexible laryngeal mask airway device  10  placed in the hypopharynx of a human with the mask covering the glottis and the airway channel extending outside the mouth. While  FIG.  15    illustrates a system including the airway device  10  and the DST  400 , exemplary embodiments of systems in accordance with the present disclosure can be formed using any one of the airway devices  10 ,  10 ′, or  30  with anyone of the DST  400  or  500  described herein. An exemplary embodiment of the DST  400  is placed through the gastric-pharyngeal access channel  150  of the airway device into the human&#39;s esophagus and stomach with the distal part and gastric eyelets  411  of the lower section  401  in the stomach while its proximal end extends outside the mouth. 
       FIG.  16    illustrates a general and common process of forming and using a system that includes an embodiment of the airway device  10 ,  10 ′, or  30  of  FIGS.  1 A,  1 B, and  3   , respectively and an embodiment of the dual suction tube (DST)  400  or  500  of  FIGS.  8  and  9   , respectively. At the first step  700 , airway device with a gastropharyngeal access channel is chosen. At step  702 , the system is assembled before being placed in a patient by passing the DST with lubrication into the gastric-pharyngeal access channel  150  via its proximal opening  151  until the tip of the DST reaches the valve  176  of the distal port  171  of the ampulla  170 . At step  704 , after induction of general anesthesia, the assembly of the airway device and the DST is placed in the patient&#39;s airway until the mask reaches the hypopharynx covering and sealing around the glottis of the patient. A supporting arm may be used to facilitate the insertion of the airway device. At step  706 , for embodiments of the airway device that include a cuff, the cuff is inflated if needed to achieve optimal seal. 
     At step  708 , before or immediately after initiation of positive ventilation, the DST is advanced further through the gastric-pharyngeal access channel, the ampulla and the distal port and its valve into the esophagus and stomach of the patient until resistance is met, that is, until the cone-shaped transitional zone of the DST engages the funnel-shaped distal port  171  of the ampulla. The engagement between the transitional zone and the funnel-shaped distal port can provide a relatively secure position for the DST, while an easy passage of the DST generally indicates adequate placement of the airway device. At this point, the DST  400  or  500  is in fluid communication with the stomach through the gastric eyelets of the gastric lumen. At step  710 , suction is applied to evacuate the stomach through the DST using vacuum to the proximal end of the gastric lumen. Adequate placement and effective ventilation via the airway device should be confirmed using the conventional method such as assessing airway compliance, minimal leak pressure, and the capnography waveform. Visual confirmation with a flexible bronchoscope through the airway channel may be used if indicated. If the seal is inadequate, a small amount of air is added to the cuff to achieve optimal seal; otherwise, the airway device is removed and replaced. During ventilation, air leak from the airway device into the stomach may be vented through the DST, preventing gastric insufflation. Gastric regurgitation may be monitored and evacuated through the DST as well. Further and subsequent steps should be followed and are described in the following paragraphs. 
     After evacuation of residual gastric fluid or content with suction through the gastric lumen, the DST can be left in place or removed, depending on the airway device used and clinical indications. For airway device  30 , which has the gastric-pharyngeal access channel  150  but no pharyngeal suction channel  140 , the DST should be kept in place for evacuation of the ampulla-pharyngeal drains through the pharyngeal eyelets of the DST as described herein. However, for airway device  10  or  10 ′, which has the gastric-pharyngeal access channel  150  and the pharyngeal suction channel  140 , the DST can be left in place for further monitoring and evacuation of gastric fluid during the surgery, and for evacuation of ampulla-pharyngeal drains as a back-up system for the pharyngeal suction channel  140 ; or the DST can be removed if there is no further indication or need for monitoring and evacuation of gastric fluid. Once the DST is removed, the tri-leaflets valve of the distal port can block or retard the fluid flowing from the ampulla into the esophagus while still allowing for air vent out of the esophagus-stomach, and the ampulla-pharyngeal drains can be accessed and evacuated through the pharyngeal suction channel  140 . Removing the DST allows more space for surgical access to the oral cavity which may benefit surgical access to the oral airway. 
     If the dual section tube (DST)  400  is being used, the suction lumen  410  is separated from (i.e., not in fluid communication with) the ampulla-pharyngeal drains because the pharyngeal eyelets  412  in the cone-shaped transitional zone are blocked by the sidewall of the distal port  171  ( FIG.  12 A ). The DST  400  can be backed out approximately  8  mm of the airway device to place the pharyngeal eyelets  412  in the ampulla so that the suction lumen is in fluid communication with the ampulla and the pharyngeal eyelets can be used to evacuate fluids from the ampulla ( FIG.  12 B ). If, however, the DST  500  is being used, the pharyngeal eyelets  531  of the pharyngeal lumen  530  are separately and independently in fluid communication with the ampulla such that evacuation of the stomach and the ampulla can occur independently and/or simultaneously when the transitional zone  503  of the DST  500  is engaged with the distal port  171  of the ampulla ( FIGS.  13 A and  14 C ). In the event that the pharyngeal eyelets  531  of the pharyngeal lumen  530  become clogged, the DST  500  can be backed out approximately  8  mm to place the pharyngeal eyelets  512  on the gastric lumen  510  in the ampulla to evacuate fluids from the ampulla ( FIG.  13 B ). For embodiments (airway device  10  or  10 ′) in which the airway device includes a pharyngeal suction channel  140 , the ampulla can be evacuated via the pharyngeal suction channel  140  independent of the DST. 
       FIG.  17    further illustrates a process of using a system including the laryngeal mask airway device  10  or  10 ′ of  FIGS.  1   , and an embodiment of the DST  400  shown in  FIGS.  8 A-B . At the first step  800 , airway device with a gastropharyngeal access channel is chosen. At step  802 , the system is assembled before being placed in a patient by passing the DST with lubrication into the gastric-pharyngeal access channel  150  via its proximal opening  151  until the tip of the DST reaches the distal port  171  of the ampulla  170 . At step  804 , after induction of general anesthesia, the assembly of the airway device and the DST is placed in the patient&#39;s airway until the mask reaches the hypopharynx covering and sealing around the glottis of the patient. A supporting arm may be used to facilitate the insertion of the airway device. At step  806 , for embodiments of the airway device that include a cuff, the cuff is inflated if needed to achieve optimal seal. 
     At step  808 , before or immediately after initiation of positive ventilation, the DST is advanced further through the gastric-pharyngeal access channel and the ampulla (including the distal port and its valve) into the esophagus and stomach of the patient until resistance is met, that is, until the cone-shaped transitional zone of the DST engages the funnel-shaped distal port  171  of the ampulla. The engagement between the transitional zone and the funnel-shaped distal port can provide a relatively secure position for the DST, while an easy passage of the DST generally indicates adequate placement of the airway device. At this point, the DST  400  or  500  is in fluid communication with the stomach through the gastric eyelets of the gastric lumen. At step  810 , suction is applied to evacuate the stomach through the DST using vacuum to the proximal end of the gastric lumen. Adequate placement and effective ventilation via the airway device should be confirmed using the conventional method such as assessing airway compliance, minimal leak pressure, and the capnography waveform. Visual confirmation with a flexible bronchoscope through the airway channel may be used if indicated. If the seal is inadequate, a small amount of air is added to the cuff to achieve optimal seal; otherwise, the airway device is removed and replaced. During ventilation, air leak from the airway device into the stomach may be vented through the DST, preventing gastric insufflation. Gastric regurgitation may be monitored and evacuated through the DST as well. Further and subsequent steps should be followed and are described in the following paragraphs. 
     At step  812 , during the surgery and upon the onset of active surgical bleeding, blood as well as secretions and surgical debris in the pharynx is intermittently evacuated with brief suction through the pharyngeal suction channel  140  via an extension catheter  145  connected to the female luer lock connector  142  of the pharyngeal suction channel. The frequency of suction may vary, depending on the amount of surgical bleeding, with the goal of preventing blood accumulation in the pharynx while also avoiding potential injury to the mucosa by continuous suction. As atmospheric air may be drawn into the system through the pharyngeal drains as well as the gastric-pharyngeal access channel, the risk of vacuum injury to the mucosa is minimized. The DST should effectively block or retard the drainage of blood from the ampulla into the esophagus, ensuring effective evacuation of blood from the pharynx through the pharyngeal suction system and preventing blood irritation to the stomach and subsequent nausea or vomiting after the surgery. If the pharyngeal suction channel  140  ceases to function properly, it can be flushed with a small amount of saline using a syringe attached to the female luer lock connector  142  to clear the blockage. Otherwise, the DST  400  can be withdrawn slightly from the airway device to unseal the pharyngeal eyelets  412  (as shown in  FIG.  12 B ) and to facilitate evacuation of blood or other fluids in the ampulla through the pharyngeal eyelets of the DST  400 . During emergence from anesthesia, the operating table can be placed in a back-up position with the patient&#39;s head raised to facilitate drainage of postnasal blood and to better support spontaneous respiration. The DST  400  can be removed while being under vacuum suction. Subsequently, frequent suction is applied to the pharyngeal suction catheter  141  to remove residual blood or continuous oozing and secretions. When the patient is able to open his/her mouth on command, the airway device is removed without cuff deflation and with continuous suction applied to the pharyngeal suction catheter. This would clear the residual blood and secretions in the upper airway as the airway device is being removed, further preventing irritation of the airway and the glottis. 
       FIG.  18    illustrates a process of using a system including the laryngeal mask airway device  30  of  FIG.  3   , which has no pharyngeal suction channel  140 , and an embodiment of the DST  500  of  FIG.  9   . At the first step  900 , airway device with a gastropharyngeal access channel is chosen. At step  902 , the system is assembled before being placed in a patient by passing the DST with lubrication into the gastric-pharyngeal access channel  150  via its proximal opening  151  until the tip of the DST reaches the distal port  171  of the ampulla  170 . At step  904 , after induction of general anesthesia, the assembly of the airway device and the DST is placed in the patient&#39;s airway until the mask reaches the hypopharynx covering and sealing around the glottis of the patient. A supporting arm may be used to facilitate the insertion of the airway device. At step  906 , for embodiments of the airway device that include a cuff, the cuff is inflated if needed to achieve optimal seal. At step  908 , before or immediately after initiation of positive ventilation, the DST is advanced further through the gastric-pharyngeal access channel and the ampulla into the esophagus and stomach of the patient until resistance is met, that is, until the cone-shaped transitional zone of the DST engages the funnel-shaped distal port  171  of the ampulla. 
     At step  910 , when the transitional zone  503  is engaged with the distal port  171  of the ampulla, the DST  500  is in fluid communication with the stomach through its gastric lumen  510  and gastric eyelets  511 , and also in fluid communication with ampulla-pharyngeal drains through the pharyngeal lumen  530  and the eyelets  531  that are located above the transitional zone and positioned in the ampulla (as shown in  FIGS.  13 A and  14 C ), apply suction to the gastric lumen to evacuate the stomach. At step  912 , during the surgery and upon the onset of active surgical bleeding, blood as well as secretions and surgical debris in the pharynx can be intermittently evacuated with brief suction through the pharyngeal lumen  530  and the eyelets  531  that are positioned in the ampulla, since airway device  30  has no pharyngeal suction channel  140 . The frequency of suction may vary, depending on the amount of surgical bleeding, with the goal of preventing blood accumulation in the pharynx while also avoiding potential injury to the mucosa. As atmospheric air may be drawn into the system through the pharyngeal drains as well as the gastric-pharyngeal access channel, the risk of vacuum injury to the mucosa is minimized. The transitional zone should effectively block or retard the drainage of blood from the ampulla into the esophagus, ensuring effective evacuation of blood from the pharynx through the pharyngeal lumen  530  and preventing blood irritation to the stomach and subsequent nausea or vomiting after the surgery. If the pharyngeal lumen  530  is clogged during the surgery, the DST  500  can be withdrawn from the airway device about five (5) to eight (8) millimeters to unseal the proximal eyelets  512  of the gastric lumen  510  (as shown in  FIG.  13 B ), which may be then used to evacuate the pharynx via the ampulla-pharyngeal drain system. During emergence from anesthesia, the operating table is placed in a back-up position with the patient&#39;s head raised to facilitate drainage of postnasal blood and to better support spontaneous respiration. Frequent suction is applied to the pharyngeal lumen of the DST  500  to remove residual blood or continuous oozing and secretions. When the patient is able to open his/her mouth on command, the DST  500  is removed with continuous suction applied to the pharyngeal lumen via its proximal three-way port  533 , followed by the removal of the airway device without cuff deflation. 
     Unlike airway devices  10 ,  10 ′, and  30 , the airway devices  20  and  20 ′ can and should be used alone, and cannot be used with the DST since they do not have a gastropharyngeal access channel to accommodate the DST. In an exemplary application, referring to  FIGS.  2 A-B , the airway device  20  or  20 ′ can be inserted into the upper airway with the mask portion  100  covering the glottis, and with the airway channel  210  and the pharyngeal suction channel  140  extending outside of a mouth of the patient. The airway device  20  or  20 ′ can allow access to the upper airway of the human for surgeries or procedures involving the upper airway while proving ventilation of lungs through the mask and the flexible thin airway channel. During positive ventilation, the tri-leaflet valve  176  of the distal port allows air vent out of the esophagus and stomach, preventing gastric insufflation due to air leaking from the airway through the mask. Upon the onset of active surgical bleeding, blood as well as secretions and surgical debris in the pharynx is collected via the pharyngeal drains-ampulla and can be evacuated with intermittent suction through the pharyngeal suction channel  140  connected via an upper port  174  to the ampulla. The frequency of suction may vary, depending on the amount of surgical bleeding, with the goal of preventing blood accumulation in the pharynx while also avoiding potential injury to the mucosa from continuous suction. As atmospheric air may be drawn into the system through the pharyngeal drains, the risk of vacuum injury to the mucosa is minimized. The tri-leaflet valve  176  of the distal port blocks or retards the drainage of blood and/or secretions from the ampulla into the esophagus, ensuring effective evacuation of blood from the pharynx through the pharyngeal suction channel and preventing blood irritation to the stomach and subsequent nausea or vomiting after the surgery. If the pharyngeal suction channel is clogged during surgery, the suction system can be flushed with saline using a syringe attached to the female luer lock connector  142 . During emergence from anesthesia, the operating table is placed in a back-up position with the patient&#39;s head raised to facilitate drainage of postnasal blood and to better support spontaneous respiration. Frequent suction is applied to the pharyngeal suction catheter to remove residual blood or continuous oozing and secretions. When the patient is able to open his/her mouth on command, the airway device is removed, without cuff deflation, while being under suction through the pharyngeal suction catheter. 
       FIG.  19 A-H  illustrates various kits that can be formed in accordance with embodiments of the present disclosure.  FIG.  19 A  illustrates a kit that includes the airway device  30  of  FIG.  3    and the DST  400  of  FIGS.  8 A-B .  FIG.  19 B  illustrates a kit that includes the airway device  30  of  FIG.  3    and the DST  500  of  FIGS.  9 A-C .  FIG.  19 C  illustrates a kit that includes the airway device  10  of  FIG.  1 A  and the DST  400  of  FIGS.  8 A-B  with or without the extension catheter  145 .  FIG.  19 D  illustrates a kit that includes the airway device  10  of  FIG.  1 A  and the DST  500  of  FIGS.  9 A-C  with or without the extension catheter  145 .  FIG.  19 E  illustrates a kit that includes the airway device  10 ′ of  FIG.  1 B  and the DST  400  of  FIGS.  8 A-B  with or without the extension catheter  145 .  FIG.  19 F  illustrates a kit that includes the airway device  10 ′ of  FIG.  1 B  and the DST  500  of  FIGS.  9 A-C  with or without the extension catheter  145 .  FIG.  19 G  illustrates a kit that includes the airway device  20  of  FIG.  2 A  with or without the extension catheter  145 .  FIG.  19 H  illustrates a kit that includes the airway device  20 ′ of  FIG.  2 B  with or without the extension catheter  145 . 
     In describing exemplary embodiments, specific terminology is used for the sake of clarity. For purposes of description, each specific term is intended to at least include all technical and functional equivalents that operate in a similar manner to accomplish a similar purpose. Additionally, in some instances where a particular exemplary embodiment includes a plurality of system elements, device components or method steps, those elements, components or steps may be replaced with a single element, component or step. Likewise, a single element, component or step may be replaced with a plurality of elements, components or steps that serve the same purpose. Moreover, while exemplary embodiments have been shown and described with references to particular embodiments thereof, those of ordinary skill in the art will understand that various substitutions and alterations in form and detail may be made therein without departing from the scope of the invention. Further still, other aspects, functions and advantages are also within the scope of the invention. 
     Exemplary flowcharts are provided herein for illustrative purposes and are non-limiting examples of methods. One of ordinary skill in the art will recognize that exemplary methods may include more or fewer steps than those illustrated in the exemplary flowcharts, and that the steps in the exemplary flowcharts may be performed in a different order than the order shown in the illustrative flowcharts.