Since its inception in the latter 1960's flexible GI endoscopy; first with a miniature film camera, then with fiber optic bundles to carry the incident image and finally culminating in video chip technology, has evolved from a mechanical curiosity to a proven life-saving system for diagnosis and therapy.  Many structures previously considered to be beyond diagnostic evaluation and therapeutics by any modality short of surgery are now open to the GI endoscopist: esophagus, stomach, duodenum, small intestine, biliary tree and pancreatic system are now accessible without use of an open surgical technique. 
Endoscopic techniques can treat and palliate conditions such as stopping of GI bleeding, polyp removal, gallstone removal, stricture dilation, foreign body removal, endoscopic stint placement for GI obstruction and a host of other procedural capabilities too numerous to mention.  The lesser morbidity and mortality with endoscopic procedures allows their use on sicker, more debilitated patents, increasing the clinical utility of endoscopic therapy. 
While endoscopic diagnosis and therapy has opened many new avenues of GI care, some of its design strengths produce some of its greatest limitations.  The endoscope is a flexible tube less than 1 cm in diameter, generally possessing one hollow bore through which instruments for injection of dye or haemostatic materials, biopsy and polypectomy attachments, and haemostatic probes are passed.  At the same time this bore is used for suctioning of secretions.  The bore is approximately 2.6 to 2.8 mm in diameter and not conducive to removal of larger diameter foreign material or highly viscous substances such as clotted blood.  Cleansing the endoscopic visual field to remove food, blood, secretions impacted food bolus or foreign body is often impossible using this small bore.  A larger bore conduit is needed to correct this shortcoming.  Since the endoscope itself really cannot be modified to rectify this shortcoming, an appliance to be used in conjunction with the endoscope would be the preferable alternative. 
Frequently, certain appliances are used in conjunction with endoscopy to aid in its use for diagnosis and therapy.  A long flexible fenestrated tube with an open proximal end is often used to clear the upper GI tract of blood, food, foreign materials and secretions.  This device uses a vacuum system for the removal of these materials and either gravity flow or pressure system to instill lavage fluid into the GI tract to help remove these materials.  This system cannot be used simultaneously with an endoscope but must be used independently and inserted blindly into the upper GI tract.  A blind insertion may cause trauma to the respiratory tree with sometimes disastrous results.  Repeated removal and replacement of the endoscope and lavage tube may also stimulate retching which can induce vomiting, aspiration of gastric contents and even severe bleeding, both serious complications.  The least number of removal and replacement of tubes against the pharynx and esophagus, the better.  Further complicating the process of alternating lavage and endoscopy is the fact that rapid bleeding in the GI tract is frequently too rapid and too difficult to clear to the point that an endoscope may be effectively used.  A lavage tube may cause a fleeting improvement in the visualization of a bleeding site, but from the time of removal of the lavage tube to the time of reintroduction of the endoscope, continued bleeding can obscure both normal enteric architecture as well as the pathologic process precipitating the problem.  A system which allowed simultaneous lavage and endoscopy would circumvent all these problems. 
Removal of foreign bodies from the upper GI tract is another common problem with potentially serious consequences.  Foreign bodies may produce pain, bleeding and obstruction in the GI tract.  Endoscopic treatment of this problem may be hampered by the need to frequently remove blood, food and secretions either prior to or at the same time as endoscopic evaluation and therapy is performed.  Endoscopic therapy must take into consideration not only proper preparation and endoscopic technique for foreign body removal, hemostasis, stricture and dilation but also safety issues such as the prevention of aspiration of GI contents and foreign bodies into the respiratory tree, and prevention of laceration of the duodenum, stomach, esophagus and pharynx.  Complicating this issue is that while a flexible polymer plastic over tube through which the endoscope and foreign bodies can be inserted and removed thus protecting surrounding structures, no system yet exists which can perform the endoscopic function while simultaneously possessing the capability to lavage out blood, food and secretions which can complicate foreign body removal.  This increases the level of difficulty in their removal as well as increases potential complications in the removal process, such as aspiration and perforation.  The ability to simultaneously see the GI tract while removing a foreign body would be a tremendous advantage over the system presently used. 
Treatment of acute lower GI bleeding is complicated by the frequent obscuration of the bleeding site by blood, mucus and stool thus seriously limiting the utility of therapeutic colonoscopy for the acute treatment of lower GI bleeding.  If blood, secretions and stool could be effectively and simultaneously removed while performing the colonoscopy, colonoscopy would be a more effective acute diagnostic and therapeutic interventional system than it is at the present time.  This would save time in that a colonoscopy could be performed without the need to perform preceding colonic cleansing using either oral osmotic cathartics or enema which takes both precious time and involves increased risk in the patient who is semiconscious and hypotensive.  The logistics in the typical medical center favors endoscopic intervention over the more involved and potentially more risky interventional angiography. 
A system is needed which can cleanse and remove blood, foreign material, secretion and stool from the upper and lower GI tracts while simultaneously performing diagnostic and therapeutic endoscopy for hemostasis and removal of impacted material.  The system must be capable of protecting GI structures from trauma and the respiratory system from aspiration of secretions, blood and foreign material. 
There have been a number of developments in this area.  U.S. Pat.  No.  4,795,424 (Burner) concerns an apparatus for controlled irrigation of the natural cavities of the human body.  It is characterized by a correcting means for equalizing the measuring signal, which represents the pressure, which is emitted by a pressure gauge according to the pressure losses and according to the differential pressure between it and the measurement of the pressure in the intervention area which corresponds to an organ.  These correcting means include a correcting circuit adapted to effect a correction according to said pressure differential and a correcting circuit adapted to take into account the pressure loss, namely the flow rate of the fluid injected through the inner duct of the endoscope and the cross section of this duct. 
This is an electrical system, designed principally for urologic endoscopy, for monitoring flow of fluid into and out of a small space by monitoring changes in pressure in the system.  This is not a lavage system but a pressure-monitoring device for fluid entering and exiting a space.  This could be used in the bladder or uterus for surgery to gauge fluid flow—it has nothing to do whatever with lavage of blood, food, dilation of strictures and, removal of foreign bodies.  This is for measuring/monitoring and not effecting a change. 
U.S. Pat.  No.  5,030,202 (Harris) discloses a lavage apparatus comprising a lavage fluid supply apparatus, a first catheter having a distal end for positioning in the uterus of an animal and a proximal end for communication with the lavage fluid supply, a pair of bilateral catheters connected to the proximal end of the first catheter for extending into respective horns of the uterus, and catheter locating means for locating the catheters in the uterus.  The first catheter defines respective supply and drain lumens.  The bilateral catheters each define respective lumens for fluid communication between the supply lumen and the interior of the respective uterine horn.  The lavage fluid supply apparatus may include a pump for supplying lavage fluid under pressure.  The supply may also include a lavage fluid storage tank for containing a volume of fluid, and a heater to maintain the temperature of the stored fluid within a predetermined range.  For use in a gravid uterus, a drain tube may be provided at the distal end of the first catheter for reaching into the depths of the uterus.  Further, vacuum drainage apparatus may be provided to drain lavage fluid from the uterus.  If desired, the lavage fluid supply may be utilized for purposes other than uterine lavages such as, for example, supplying fluids for intravenous infusion.  It cannot be used for simultaneous endoscope and lavage in either the upper or lower gastrointestinal tract.  Neither is it portable or disposable.  One cannot effectively dilate and remove foreign material with this device. 
U.S. Pat.  No.  5,620,408 (Vennes et al.)  discloses an endoscopic over-tube for receiving and guiding medical instrumentation into the upper alimentary canal of a patient.  The endoscopic over-tube has a bite block for insertion and retention in the mouth of the patient.  The endoscopic over-tube also has a flexible protective sheath engaging the bite block and adapted for insertion into the upper alimentary canal of the patient.  The sheath includes a stiffened region that insulates the posterior wall of the patient's pharynx from medical instrumentation as the medical instrumentation is intubated through the sheath and into the patient's alimentary canal. 
This tube is solely used to help an upper endoscopic bypass direct control of the pharynx by the endoscope protecting against irritation and gagging and possibly protecting the upper airway.  The system is short and too rigid to be used for lavage.  It cannot be sealed for lavage purposes.  It cannot be moved when it is properly inserted.  The new arrangement system is not as useful for lavage, hemostasis, foreign body removal, and dilation.  It could not be used to simultaneously endoscope and lavage a patent, removing either blood, food or other foreign materials solely and expeditiously to accomplish the same procedure. 
U.S. Pat.  No.  5,827,177 (Oneda et al.)  discloses an endoscope sheath assembly usable within an elongated flexible endoscope to isolate a portion of the endoscope from an external environment during a therapeutic or diagnostic endoscopic procedure.  The sheath assembly has a sheath with an elongated flexible endoscope tube, a plurality of working bores extending the endoscope tube, and a low-friction, fabric isolating sleeve positioned within the endoscope tube and surrounding portions of the working bores.  The isolating sleeve includes first and second sleeve lumens formed therein through which respective working bores extend.  The coefficient of friction between the isolating sleeve and the working bores is less than the coefficient of friction between the working bores themselves so that working bores are frictionally isolated from each other, from the endoscope tube, and from the insertion tube to reduce resistance to articulation of the endoscope. 
This is an endoscope with distensible elastomeric working bore within the endoscope tube for passage of instruments during diagnostic or therapeutic endoscopy.  It is just a modified endoscope with the same failing described above: the bores are inadequate for removal of food, blood clots, passage of rigid dilators and removal of foreign bodies, let alone lavage and endoscopic treatment simultaneously. 
U.S. Pat.  No.  5,876,379 (Harben) discloses an endoscope for use with an elastomeric sheath for performing an endoscopic procedure.  The endoscope includes a body, an insertion tube extending away from the body and terminating at a distal end portion, and a sheath retainer connected to the distal end portion of the insertion tube for releasably retaining the sheath on the insertion tube in a substantially fixed position during the endoscopic procedure.  The sheath is an elastomeric member movable between a radially expanded position and a contracted position, and the sheath is biased toward the contracted position.  The sheath retainer is a generally C-shaped member having a pair of retaining tabs spaced apart from each other and extending away from an outer surface of the insertion tube's distal end portion to define a working bore retaining area there between.  The retaining tabs are positioned and sized to engage a portion of the sheath at its distal end portion and to prevent the distal end portion of the sheath from moving axially relative to the distal end portion of the insertion tube, particularly during an endoscopic procedure. 
This is not a lavage system but an endoscope covered by a tight-fitting elastomer membrane keeping the visual system of the endoscope in close proximity to a biopsy-utility bore.  This is just an endoscope tube composed of two pieces covered by an elastomeric sheath.  It has the same failings of contemporary endoscopes: no ability to lavage, dilate or remove foreign bodies. 
U.S. Pat.  No.  6,149,633 (Maaskamp) discloses a system which utilizes an endoscope and irrigation fluid during surgery within a body orifice, and in which irrigation fluid is withdrawn via a principal path into a suction canister, there is a substantially constant suction and withdrawal rate from the operative site to limit absorption of irrigation fluid within the patient, because a bifurcated flow path that leads to the suction canister not only from the endoscope but also from a drain bag receiving overflow from the body orifice via a tailored drape includes a substantially greater flow impedance in the drain bag path.  The common suction line joined to the endoscope line and the drain bag line draws a flow through the endoscope that predominates, to maintain substantially constant withdrawal of irrigation fluid via that path, and substantially eliminates the possibility of loss of suction. 
This is a system to meter fluid into body cavities during laparoscopy and not endoscopy.  It measures fluid going into the cavity and fluid coming out of the cavity to prevent fluid overload of patient during surgery.  It has nothing to do a lavage of GI bleeding, dilation of stricture and removal of foreign bodies.  It is solely a fluid-monitoring system. 
U.S. Pat.  No.  6,187,346 (Neuwirth) discloses a method and composition for effecting necrosis of a tissue lining of a mammalian body cavity, particularly a uterine endometrium, by introducing an applicator comprising a hysteroscope housing a first and a second catheter connected to a catheter into the uterus, distending the uterus by introducing CO2 gas under pressure, delivering a silver nitrate paste to the endometrium through the first catheter and allowing the paste to remain a sufficient amount of time to substantially cauterize the entirety of the tissue lining, particularly the endometrium and delivering an aqueous sodium chloride solution to the uterus through the second catheter thereby neutralizing the silver nitrate and rinsing the uterine cavity. 
This system is a hysteroscope with two bores to one apply a silver nitrite paste to the lining of the uterus/endometrial and the second to supply a sodium chloride solution to the silver nitrite-treated area to neutralize it.  This system is used to effect necrosis and chemical cauterization of tissue, neutralize the cauterizing substance and rinse tissue.  It is not an addition to an endoscope for simultaneous lavage of blood, foreign material, dilation of stricture and removal of foreign bodies.  It cannot be adapted to any endoscope of popular design.  The system has the same faults as described in GI endoscopes previously described : the bores are too small, it is non-flexible, and has no ability to remove foreign bodies or dilate strictures.  It is a low flow system, with no ability to endoscopically perform hemostasis, biopsy and tissue removal while simultaneously lavaging the cavity the system has been introduced into.  All foreign material goes back through the bore which may close.  Alternatively, the foreign material just runs out of the uterus into the vagina where it is either suctioned or just spills out of the vagina into a receptacle.  This is not an option in the upper GI tract due to the fear of aspiration of fluid into the lungs. 
U.S. Pat.  No.  6,203,493 (Ben-Haim) discloses a locatable endoscope attachment including an attachment connectable to an insertion tube portion of an endoscope for determining the endoscope's position; and one or more sensors, fixedly positioned with respect to the attachment, which are used for determining the positions of the one or more sensors.  Preferably, when the attachment is fixedly attached to the endoscope, the one or more sensors are distanced from elements of the endoscope which interfere with determining the positions of the one or more sensors.  This system places a magnetic field position sensor on the surface of an endoscope to determine its location in the intestinal tract.  It has nothing to do at all with endoscopic lavage or has any real direct therapeutic/interventional application. 
U.S. Pat.  No.  6,322,495 (Snow et al.)  discloses a system to place an intestinal feeding tube visually through the abdominal wall of the subject and direct it down the GI tract.  It is solely for visualizing the position of the proximate end of the system for purposes of placement.  It is designed to not work with or need a regular endoscope and has no capabilities for lavage, hemostasis, foreign body removal, etc. 
U.S. Pat.  No.  6,428,510 (Kadan) discloses a system for performing a single portal diagnostic needle arthroscopy and lavage comprised of a hand piece having valves for irrigation and suctioning and a diagnostic cannula attached to the hand piece.  An arthroscope is passed through the hand piece and the diagnostic cannula and allows the procedure to be performed through a single port of entry into the interior of the joint.  The system includes a mobile cart with a camera and light system and a high-resolution monitor.  An air compressor is the pressure source powering the individually controlled irrigation pumps which drive the irrigation fluid through an irrigation hose to the hand piece while a vacuum suction console provides suction for collection of fluid in canisters mounted on the mobile cart.  The system includes a biopsy cannula that can be easily exchanged for the diagnostic cannula using an exchange rod.  The biopsy cannula is comprised of a pair of piggyback bores, one for visualization, diagnosis, irrigation and suction, while the other is for insertion of a biopsy instrument or other surgical devices.  The biopsy instrument is comprised of a thin, approximately 1 mm flexible shaft connected to a forceps configured jaw at the distal end for performing surgical procedures in the joint compartment.  A ring handle configuration at the instruments proximal end controls the jaws.  Both the diagnostic cannula and biopsy cannula have couplings that include an auxiliary valve for introducing medication and drugs into the joint compartment as well as for removal of sterile synovial fluid. 
While a well-designed system for arthroscopy biopsy and cleaning of joint spaces, this design does not apply to a lavage system to be used via the GI tract.  The system cannot be used for dilation or foreign body removal.  The arthroscope and lavage system are really not separable and due to this and its construction a system using the diagram no matter how scaled up would have functional problems and clogging with mucus, blood, food and other foreign material.  This will obviate its effectiveness. 
U.S. Pat.  No.  6,461,294 (Oneda et al.)  discloses an apparatus and methods for attaching and forming enclosed inflatable members on an endoscope assembly with a disposable sheath are disclosed.  In one embodiment, an apparatus includes a flexible and resilient cuff member that is positioned on the outer surface of the disposable sheath and sealably and fixedly bonded to the sheath cover material at the cuff edges to form an annular space capable of being inflated.  The inflatable member formed thereby is inflated through a lumen internal to the sheath that has an opening into the interior annular space.  In another embodiment, the annular space may be divided into separate inflatable lobes.  In still another embodiment, the cuff member is a flexible and resilient member that is substantially toroidal in shape that is positioned on the outer surface of the sheath.  In a further embodiment, the inflatable member is formed from an excess length of sheath cover material disposed on the disposable sheath.  A single reentrant fold of sheath material is formed with an edge that is sealably and fixedly bonded to the sheath cover material to form an annular space capable of inflation.  In alternate embodiments, the excess length of cover material may be used to form members with dual reentrant folds that comprise inflatable members with single and dual inflatable lobes. 
This is an inflatable outer elastomeric sheath to hold a bronchial endoscope in proper position for bronchial biopsy.  It has nothing to do with endoscope lavage, etc. 
U.S. Pat.  No.  6,520,951 (Carillo, Jr. et al.)  discloses a single operator exchange biliary catheter having a common distal lumen.  The biliary catheter includes an elongate shaft having a proximal portion defining an ancillary lumen and a distal portion defining a common guide wire and ancillary lumen.  The common distal lumen reduces the profile of the distal portion of the shaft.  The elongate shaft also includes a proximal guide wire port disposed between the proximal end of the shaft and the distal end of the shaft to facilitate single operator use.  A seal may be disposed adjacent the proximal guide wire port to thereby seal the port.  Preferably, the shaft includes a single lumen distal portion and a bilumen proximal portion.  The single lumen distal portion of the shaft may be curved and may include a tapered or spherically shaped distal tip. 
This is an easily exchanged biliary catheter used to stint bile duct strictures for trist obstruction.  It is more easily placed and exchanged.  It has nothing to do with endoscopic lavage, foreign body retrieval, dilation and cannot be used simultaneously with an endoscope. 
The systems presently in use and described above are inadequate due to certain inherent disadvantages:
A) The only bores presently available in all endoscopes commonly used in clinical practice are woefully too narrow to accommodate very viscous or large solid materials, making their removal impossible.     B) No system exists specifically adapted for endoscopes, either upper or lower, to allow simultaneous instillation of solubilizing lavage fluid with its subsequent removal by a vacuum system while performing endoscopic visualization and manipulation of GI structures.     C) Foreign bodies, large chunks of meat or vegetables cannot be removed by lavage systems in general use.  Nor do these systems allow for endoscopic visualization of the bolus while it is being removed.     D) Flexible tubes used to remove harmful foreign bodies by producing a shielded bore through which the material is removed without risk of injury to surrounding structures (GI and respiratory) do not have lavage capability.     E) No endoscopic lavage system is as yet produced which can function with or without the endoscope in place.     F) No such system such as described in E) exists which can be used to dilate strictures in the GI tract using either flexible or balloon dilators.     G) No endoscopic lavage system exists which can be used concomitantly with endoscopic visualization of the lower GI tract (i.e., colon).  The system would not only remove blood and mucus from the GI tract, but also any and all fecal material which may be obscuring the vision of the endoscopist.     H) No such system described in G) exists which may be used independently of the endoscope to draw gas and fluids from the lower GI tract.  This could be very important in the treatment of such conditions as ileus or volvulus, where temporary colonic decompression by colonoscope is frequently used for acute intervention but prolonged decompression might be of greater clinical advantage.     I) The use of laser therapy to open areas of the GI tract closed by cancer sometimes produces smoke from the burned flash which can both occlude the view of the procedural area and also produce a noxious smell.  An endoscopic vacuum system would be useful for the removal of offending gases and help to maintain a clear operative field.  No such system is presently available. 
Development of a system which can cleanse and remove blood, foreign material, secretion and stool from the upper and lower GI tracts while simultaneously performing diagnostic and therapeutic endoscopy for hemostasis and removal of impacted material represents a great improvement in the field of endoscopy and satisfies a long felt need of the gastroenterologist.