This application is based upon U.S. provisional application Ser. No. 61/480,625 filed Apr. 29, 2011 and U.S. provisional application Ser. No. 61/533,389 filed Sep. 12, 2011, the disclosures which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
This invention relates to testing the gastric valve in a patient and assessing the functioning of a patient's gastric valve and external urethral sphincter using an involuntary reflex cough test.
BACKGROUND OF THE INVENTION
Commonly assigned U.S. application Ser. No. 13/354,100 filed Jan. 19, 2012 by the same inventors, the disclosure which is hereby incorporated by reference in its entirety, discloses a system and method of diagnosing acid reflux using an involuntary reflex cough test. In one example as disclosed, a nasogastric/orogastric (Ng/Og) device is inserted into the stomach and the involuntary reflex cough epoch induced. The intra-abdominal pressure and elevational reflux along the Ng/Og device is measured. In an example, the functional status of the gastric valve is determined based on the measured intra-abdominal pressure and elevational reflux along the catheter. This is a limited analysis that is not always accurate to determine whether there is a reflux problem, requiring an Ng/Og device, which in some cases can interfere with the gastric valve and the lower esophageal sphincter. In another example, an Ng/Og device with an esophageal cuff is used with a sequence of steps, such as inflating a cuff, inducing the involuntary reflex cough epoch, determining if acid reflux has occurred, deflating the esophageal cuff, and again inducing the involuntary reflex cough epoch. Results can be used to determine the functional status of the gastric valve. This is a limited type of test that has not always been found advantageous.
Use of the involuntary reflex cough test with or without a voluntary cough test is also disclosed in commonly assigned U.S. patent application Ser. Nos. 11/608,316 filed Dec. 8, 2006; Ser. No. 11/550,125 filed Oct. 17, 2006; Ser. No. 12/643,134 filed Dec. 21, 2009; Ser. No. 12/643,251 filed Dec. 21, 2009; Ser. No. 12/878,257 filed Sep. 9, 2010; Ser. No. 12/878,281 filed Sep. 9, 2010; and Ser. No. 12/878,316 filed Sep. 9, 2010; the disclosures which are all hereby incorporated by reference in their entirety. The '257, '281 and '316 applications disclose oral-esophageal-gastric devices, some with esophageal cuffs and/or reflux measurement systems that can be used to assess GERD or determine stress urinary incontinence in some examples using the involuntary reflex cough tests alone or in combination with the voluntary cough test.
In one current test used to determine gastric reflux, fluoroscopy is used. A clinician or doctor will conduct a radiology sweep and use fluoroscopy, also termed video fluoroscopy. A patient swallows a barium drink, for example, containing barium sulphate, typically about 500 to about 1,000 milliliters. The patient lays on a table and the pictures are taken. Often, a tablet or drink is ingested, also termed a fizzy, to produce gas, which acts similar to Alka-Seltzer. Thus, the barium and gas exists in the stomach. Often the patient will lay on their left or right side or the clinician will tilt the patient over such that the head is down. At this point, it is possible to determine if there is acid reflux (or stomach back-up into the esophagus) by viewing the barium. In that respect, the clinician is testing the gastric valve, but the clinician also often claims they are also testing the lower esophageal sphincter (LES). Practitioners have found that test confusing and note reliable indicators are required to determine competency of the gastric valve relative to the lower esophageal sphincter (LES).
SUMMARY OF THE INVENTION
A system and method in accordance with a non-limiting example tests the gastric valve in a patient. A contrast agent is administered into the esophagus of the patient, followed by inducing an involuntary reflex cough epoch within the patient to isolate the gastric valve from the lower esophageal sphincter (LES). The flow of contrast agent is detected during the involuntary reflex cough epoch using an image sensor to determine whether stomach reflux occurred indicative of a malfunctioning gastric valve. A fluoroscopic instrument is used to detect whether stomach reflux has occurred in one example.
The involuntary reflex cough epoch can be induced by introducing a chemo-irritant using a nebulizer by having the patient inhale the irritant. It is also possible to supply the contrast agent by having the patient swallow Barium Sulfate.
The flow of contrast agent can be detected at the level of the LES. In another example, the contrast agent is swallowed and the patient is positioned in a semi-incumbent lithotomy position when inducing the involuntary reflex cough epoch. A platform supports the patient in one example and the imaging sensor is mounted to the support in a position to image the flow of contrast through the esophagus at the LES. A moveable support arm and swivel adapter mounts the nebulizer. In another example, a processor is connected to the imaging sensor and receives imaging data from the imaging sensor regarding the flow of contrast agent and reflux and is configured to process the data and estimate the severity of the malfunctioning gastric valve.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become apparent from the detailed description of the invention which follows, when considered in light of the accompanying drawings in which:
FIG. 1 is a flowchart illustrating a sequence of steps for isolating the gastric valve to assess its function in accordance with a non-limiting example.
FIG. 2 is another flowchart illustrating a sequence of steps for isolating the gastric valve and external urethral sphincter to assess their function in accordance with a non-limiting example.
FIG. 3A is a fragmentary view of an example of a kit having components for use with the methodology described relative to FIGS. 1 and 2 in accordance with a non-limiting example.
FIG. 3B is a view showing a system that includes a patient bed as a platform and imaging sensor for performing the methodology of FIGS. 1 and 2.
FIG. 4A are images for the inspiration continence reflex (ICR) as part of the involuntary reflex cough test and showing the LES.
FIG. 4B is a nerve conduction graph showing the inspiration continence reflex.
FIG. 5A are images showing a barium swallow during breath-hold.
FIG. 5B is a nerve conduction graph for the barium swallow during breath-hold.
FIG. 6 are images of a barium swallow during breath-hold in the LES.
FIG. 7A are images showing the barium swallow during the laryngeal expiration reflex.
FIG. 7B is a nerve conduction graph showing the laryngeal expiratory reflex.
FIG. 8 are graphs showing pressure recordings of the internal urethral sphincter (IUS) and LES that are synchronized with respiration.
FIG. 9 is a graph showing the relative latencies of the IUS and LES with deep inspiration and expiration.
FIGS. 10A and 10B are respective urodynamic (UD) tracings of a series of forcible voluntary cough in a female subject who has moderate/severe SUI followed by the induced reflex cough test.
FIG. 11 is a graph showing the results of the breath-hold with the maintained pressure elevation in the LES and IUS.
FIGS. 12-16 are EMG and catheter pressure results for the LES-IUS in which dotted vertical lines in FIGS. 12, 13 and 16 indicate the internal urethral sphincter (IUS) synchronously contracted with deep inhalation (inspiration).
FIG. 17 is a simplified plan view of a catheter that can be used for urodynamic and medical diagnostic testing in accordance with a non-limiting example.
FIG. 18 is a simplified plan view of another example of a catheter similar to that shown in FIG. 17 that can be used for urodynamic and medical diagnostic testing in accordance with a non-limiting example.
FIG. 19 shows a urinary continence pad that can be used with urodynamic catheters of FIGS. 17 and 18.
FIG. 20 is a plan view of an Ng/Og device or catheter that can be used for testing for acid reflux.
FIG. 21 is a fragmentary plan view of a handheld processing device that can be used in conjunction with various catheters and Ng/Og devices or other catheters and/or nebulizers.
FIG. 22 is a block diagram showing example components of a handheld processing device such as shown in FIG. 21.
FIG. 23 is a block diagram showing an outline of the laryngeal expiratory reflex (LER) and results with the intrinsic sphincter deficiency and esophageal, urinary and fecal continence.
FIGS. 24A and 24B are graphs detailing what occurs during LER with intrinsic sphincter activity (FIG. 24A) and voluntary cough pathways (FIG. 243).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Different embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown. Many different forms can be set forth and described embodiments should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art.
Research on the LES and gastric valve indicates there is a problem often with the gastric valve and there is a need for a more ready test to assess the competency of the gastric valve. In accordance with a non-limiting example, the involuntary maneuver, i.e., the involuntary cough test is employed, such as described in the copending and commonly assigned U.S. patent applications identified above.
FIG. 1 is a flowchart showing a general sequence of steps that can be used for isolating the gastric valve and determine if the gastric valve is competent and functioning adequately in one example. The kit shown in FIG. 3A can include the components for use with this methodology described relative to FIG. 1 and be used with the test system shown in FIG. 3B as explained below.
The sequence begins with a barium swallow (block 30) immediately followed by the involuntary reflex cough test, i.e., iRCT, such as by inhaling a chemo-irritant such as L-tartrate through a nebulizer in one non-limiting example (block 32). The involuntary reflex cough test isolates the gastric valve from the LES. A determination is made using video fluoroscopy, for example, if the reflux has occurred (block 34). If not, the gastric valve is competent and correctly functioning (block 36). If reflux occurs, then the gastric valve is incompetent and is malfunctioning since it is allowing the reflux (block 38). It is possible to determine the severity of the reflux (block 40), for example, by measuring the amount of reflux that occurs during the involuntary reflex cough epoch to estimate the severity of the malfunctioning gastric valve. This can be accomplished using enhanced fluoroscopy or using a Ng/Og catheter located at the LES or other location as later described to determine the extent of reflux.
FIG. 2 is another flowchart showing a sequence of steps used for assessing the competency of the gastric valve and isolating the gastric valve from the LES and also isolating the external urethral sphincter from the internal urethral sphincter to determine stress urinary incontinence.
The process begins by inserting a urinary catheter in the patient with a pressure sensor in one example and a sensor located at the internal urethral sphincter in an example. The Ng/Og tube may include at least one sensor to be positioned at the LES and pH sensor at different positions. EMG pads can also be positioned at appropriate locations at the mid-axillary line of the T7-8 internal space (block 50). This could also include the paraspinals. The bladder is filled such as with saline solution (block 52). Barium or other contrast material is swallowed (block 54) and the involuntary reflex cough test induced (block 56). Two analysis paths are shown. A determination is made whether urine leakage occurred (block 58). If not, then the external urethral sphincter is competent and functioning adequately (block 60). If yes, then the external urethral sphincter leaked indicative of stress urinary incontinence (SUI) (block 62). Some determination of the severity of SUI or other problems can possibly be determined through analyzing the EMG results together with any intra-abdominal pressure that has been recorded during the involuntary reflex cough epoch. Reference is also made to the incorporated by reference applications for appropriate data and analysis regarding same. A determination is also made whether reflux occurred (block 64). If not, then the gastric valve is competent and functioning adequately (block 66). If yes, then the gastric valve is incompetent and is not functioning correctly (block 68). By using a Ng/Og tube or advanced imaging of the contrast agent, e.g., Barium Sulfate, it is possible to determine the severity of the reflux (block 70) such as measuring the amount of reflux at the LES and other locations within the esophagus.
A patient kit for assessing the gastric valve in conjunction with fluoroscopy and the EUG can be provided and an example is shown in FIG. 3A at 100. Items in this illustrated kit include:
1) Pneumoflex or USA Flex 20% tartaric acid in 3 ml unit dose vial 102;
2) 1000 ml Barium sulfate USP 104;
3) Ion Nebulizer or Crossfire Nebulizer 106;
4) Swivel adapter for nebulizer 108;
5) Protocol information sheet 110;
6) EMG pads 112;
7) Ng/Og tube or catheter 114; and
8) Urinary catheter 116.
The purpose of this kit 100 is to simplify the assessment of the gastric valve functioning (and/or external urethral sphincter) using the involuntary maneuver, i.e., involuntary reflex cough test (iRCT) to increase the intra-abdominal pressure to isolate the gastric valve while inhibiting the LES and, in some examples, isolating the external urethral sphincter. Evidence of gastric reflux can be observed directly using video fluoroscopy and evidence of SUI determined by isolating the external urethral sphincter to determine when there is urine leakage.
As shown in FIG. 3A, a handheld processing unit, such as described later relative to FIGS. 21 and 22, can be associated with the kit 100 and includes catheter inputs, EMG and other inputs.
It is well known that the gastric valve allows food to enter the stomach but prohibits reflux of gastric acid into the esophagus. As to the patient kit 100, one aspect is the use of the swivel adapter 108 for the nebulizer such that when the patient is turned over, the nebulizer through use of the swivel adapter can be more readily used by a doctor.
There have been a number of previous tests to distinguish different urinary incontinence problems including: 1) increasing the intra-abdominal pressure using a Valsalva maneuver; 2) having the patient jump up and down; or 3) generating one or more strong voluntary coughs. Through much clinical work, such as described herein and in the copending and incorporated by reference patent applications identified above, it has been determined that the involuntary reflex cough test (iRCT) activates the nucleus ambiguus, as compared to the voluntary reflex cough test.
FIG. 3B shows a patient examining system 150 for imaging any contract agent that can be used to implement the methodology as described. The patient examining system includes a bed 152 supported on a swivel/pivot 154 that is typically motor driven and allows the bed to be rotated and pivoted to place the patient in any predetermined position as inclined or turned over, if necessary. A nebulizer 156 is supported on a swivel adapter 158 and rotatable into various positions. The nebulizer 156 can be removable and could include a separate canister (shown by dotted lines at 15) or have nebulized medicine fed through a support arm 159 associated with the nebulizer and swivel adapter 158. Imaging sensor 160 can be positioned adjacent the patient for imaging barium or other contrast agent the patient has swallowed (or been forcibly administered depending on whether the patient is conscious). The processing unit 162 includes various inputs as described relative to the processing unit 118. The processing unit 162 can be a handheld processing unit or a fixed computer connected to the imaging sensor and various catheters inserted in the patient. The imaging sensor 160 in one example is a fluoroscopic instrument configured to image the contrasting agent. The imaging sensor is typically connected to the bed and moveable into a position adjacent the patient to image the contrast agent as it flows through the esophagus into the stomach during the involuntary reflex cough epoch. Data is transferred to the data processing unit where the data is processed and the amount of reflux that occurs during the involuntary reflex cough epoch measured to estimate the severity of the malfunctioning gastric valve in one example or the extent of the gastric valve adequate functioning. This could be accomplished, for example, by comparing a plurality of photomontages taken by the image sensor during the involuntary reflex cough test.
It is possible for a series of photomontages to be viewed by a clinician such as those photomontages shown in FIG. 7A and determine the extent of reflux and through experience make an estimate as to the severity of the malfunctioning gastric valve. Also, imaging data can process the photomontages and make an estimate based on various algorithms that could be supplied to the processing unit. Additionally, the amount of reflux that occurs during the involuntary reflex cough epoch can be measured using an Ng/Og catheter that has various pressure sensors and pH sensors along its length from the stomach and gastric valve up to the LES and upward through the esophagus. Greater amounts of reflux would have greater pressure that could be measured. Also, the amount of reflux that rises along the Ng/Og catheter tube would be an estimate of the severity of the malfunctioning gastric valve since greater amounts of reflux would indicate a more severely malfunctioning gastric valve in some examples.
The iRCT selectively activates the Medial Motor Cell Column (MMCC) of the spinal cord rather than the (Lateral) LMCC to fire muscles embryologically predetermined to be involuntary cough activated muscles in the pelvis. In the past in the field of urology, urologists did not selectively activate MMCC without overtly activating the LMCC. Magnetic stimulation or electrical spinal cord stimulation activate both cell columns and thus it is not possible to sort out pathology with these tests. Magnetic stimulation or other approaches from CNS activation set off both columns. The involuntary reflex cough test activates embryologically predetermined muscles for airway protection and continence that travel primarily through the MMCC in the spinal cord.
The laryngeal expiratory reflex (LER) is a brainstem-mediated reflex that initiates an immediate series of expiratory coughs without an inspiratory phase. The LER is the involuntary reflex that neurologically protects the upper airway from noxious aspirants and, as such, it has a critical neurological function, which is unique to humans. The induced reflex cough test (iRCT) can be triggered such as by using a nebulized 20% solution of a mild chemoirritant, such as tartaric acid, to elicit in patients a LER. The iRCT is characterized by a series of, at least, five expiratory reflex coughs (C5) with a typical 17 ms latency to the external abdominal oblique (EAO) muscles. During the LER, contraction of the external abdominal oblique (EAO) muscles compress the abdominal viscera, which push against the relaxed diaphragm superiorly for the expiratory phase and push inferiorly against the urinary bladder and rectum, with a concomitant increase in intra-abdominal pressure (IAP).
Since reflex cough is expiratory and is not preceded by diaphragmatic contraction associated with inspiration, the iRCT indicates the native tonicity and function of the urethral sphincter (US) and lower esophageal sphincter (LES), which is typically critical in the diagnosis of SUI and GERDS, respectively. Animal models cannot adequately study VC and the LER, since the animals are surgically decerebrated and intubated.
The physiological functions of the lower esophageal (LES) and internal urethral sphincters (IUS) change depending on whether there is a voluntary or involuntary respiratory cough maneuver. Clinical trials and testing were accomplished using prospective, barium videofluoroscopy study (BSV) of the LES on 4 healthy adult males during voluntary cough (VC), laryngeal expiration reflex (LER) as an involuntary cough, breath-hold maneuvers and normal inspiration. A subject had fiberoptic pressure catheters placed in the LES and IUS, and EMG recording of the right T7-8 intercostals during respiration. The BSV showed closure and relaxation of the LES corresponding to the inspiration and expiration of VC. BSV showed patency of the LES during the LER. BSV showed closure of the LES during the deep inspiration/breath-hold event. Pressure catheters in the LES and IUS showed increased pressure during inspiration. These observations suggest that pulmonary inspiration afferents elicit a patterned reflex motor response to the LES and IUS, referred to as the inspiration continence reflex (ICR).
The Breuer reflex describes pulmonary inspiration afferent fibers with separate pulmonary expiration afferent fibers. The respiratory cycle is modified in many ways and by many influences that also activate the expiratory muscles for respiration. Breuer found that when the lung was distended by inspiration, pulmonary afferent impulses were conveyed to the brainstem via the vagus nerve and these afferent impulses reflexively initiated expiration. When the lung was deflated, other pulmonary afferent receptors were stimulated and their impulses, also conveyed to the brainstem by the vagus nerve, reflexively initiated the next inspiration. This report was one of the first feedback circuits for reflex self-regulation of respiration in mammals.
Recent clinical trials by the inventors on using voluntary cough (VC) and the laryngeal expiration reflex (LER) have been investigated using these respiratory maneuvers to assess stress urinary incontinence (SUI) in women and neurological airway protection in humans and are set forth. The urodynamic tracings from the SDI clinical trial suggested that the inspiration during VC may stimulate pulmonary afferent fibers that may directly activate closure of the internal urethral sphincter (IUS).
The relationship between inspiration and expiration, and the effects of reflex regulation of respiration on structures such as the internal urethral and lower esophageal sphincters have not been reported in the past. Attention is referred to the articles by: Bishop B, Bachofen H. Comparison of neural control of diaphragm and abdominal muscle activities in the cat. J Appl Physiol 1972; 32:798-805; Bishop B, Bachofen H. Vagal control of ventilation and respiratory muscles during elevated pressures in the cat. J Appl Physiol 1972; 32:103-112; and Breuer J. Die Selbststeuerung der Athmung durch den Nervus vagus. Stitzungsberichte der kaiserlichen Akademie der Wissenschaften Mathematisch-naturwissenschaftliche Classe, Wien 1868; 58:909-937.
However, the analysis of the urodynamic data during the SDI clinical trials using voluntary and involuntary cough maneuvers led to an investigation of the effect of inspiration and expiration on IUS and LES activity of the instant application. It is believed based on clinical trials as described and that during the inspiratory and expiratory components involved in voluntary and involuntary cough and breath-hold maneuvers, the inspiration neurophysiological system, as described by Breuer and Bishop, also controls the IUS and LES function.
A prospective, barium swallow videofluoroscopy (BSV) study and a cohort study of the IUS and LES using fiberoptic pressure catheters was performed. Four normal, healthy male subjects participated in the BSV study and one subject participated in both the BSV and catheter studies. After review of the study protocol, informed consent was obtained from all subjects. BSV studies of the LES were performed, using only thin barium solution, on each subject. The subjects were standing for all BSV test maneuvers using a standing anterior-posterior view. Videofluoroscopic photomontages were captured at 3-second intervals and analyzed for each maneuver.
For the VC, each subject swallowed a small cup of thin barium solution followed immediately by a deep inspiration and a VC. The BSV captured, at the level of the LES, a photomontage of the barium flow during the VC.
The breath-hold maneuver required the subject to perform a deep inspiration and breath-hold followed immediately by swallowing a small cup of thin barium solution. All of the photomontages were visually analyzed to determine the relationship of the barium to the position of the LES and diaphragm.
The induced reflex cough test is a cough provocation test that stimulates the laryngeal expiratory reflex (LER). The LER is a series of expiratory coughs that together form the cough epoch, which occurs without a significant preceding inspiration. This LER cough epoch caused five coughs (C5) with an average duration of 14.8 seconds.
Various components and materials were used to perform the iRCT in this example. These components include a vial containing a 20% solution of tartaric acid such as manufactured by Nephron Pharmaceutical, Inc. of Orlando, Fla.; jet nebulizer; an oxygen flow meter; an oxygen tank; and gloves and safety mask. The jet nebulizer was FDA approved for use in the U.S. and bore the CE Marking designating the manufacturer\'s compliance with Council Directive 93/68/EEC.
For the BSV study using the iRCT, the subject swallowed a small cup of thin barium solution immediately followed by administration of the iRCT. The BSV captured, at the level of the LES, a photomontage of the flow of the barium during the LER involuntary cough maneuver. The system such as shown in FIG. 3B could be used.
The four subjects had nasogastric and urethral fiberoptic, disposable catheters (#10 and #7 French catheters, respectively in this example) with the sensors placed at the level of the LES and IUS, respectively. Electromyography (EMG) electrodes were placed at the mid-axillary line of the T7-8 intercostal space and were used to confirm the inspiratory activity of the intercostal muscles. A Lumax TS Pro catheter was used to record LES and IUS pressures and EMG activity. However, the handheld unit as described relative to FIGS. 21 and 22 could be used to record all data and process it. All urodynamic (UD) equipment and catheters used in this study were FDA approved for use in the U.S. and bore the CE Marking designating the manufacturer\'s compliance with Council Directive 93/68/EEC. These components can be sold as a kit and packaged as a system as described before.
The subject was positioned in a semi-recumbent lithotomy position (approximately 60 degrees head up). The subject performed deep and shallow breathing and breath-hold maneuvers with simultaneous recording of LES and IUS pressures, and EMG intercostal inspiratory activity. The recordings were saved on the Lumax TS Pro in this example for analysis of pressure waves and EMG activity.
BSV followed immediately by the VC showed transient interruption of barium at the LES during inspiration, which released with expiration as shown at FIG. 4A. The VC had phases of inspiration, expiration and recovery (shown in the photographs), lasting approximately 6 seconds. This result was reproducible in all subjects. It is believed that the ICR is dependent upon the initiation of the vagal pulmonary inspiration afferent fibers to the Nucleus Tractus Solitarius (NTS) for the activation of the patterned sequence of motor responses elicited by motor nuclei associated with every inspiration. These include the Phrenic, Dorsal Motor and Sacral Autonomic Nuclei, which gives rise to diaphragm activation and the inhalation tonicity closure of the LES and the IUS. This sphincter closure maintains continence, during volitionally elevated IAP events. The pulmonary expiration afferent fibers to the Nucleus Tractus Solitarius (NTS) release the diaphragm activation and the inhalation tonicity closure of the LES and IUS. The sequence above in FIG. 4A is barium swallow (first film) followed immediately by deep inspiration (middle film), which closes the LES and stops the barium (third film). The expiration in voluntary cough releases the LES and allows barium to enter the stomach. The ICR (Inspiration Continence Reflex) event probably occurs with the activation of pulmonary inspiration afferent fibers and the response may vary according to the activation of different motor nuclei depending on the rate and depth of inspiration. FIG. 4B shows a schematic diagram of ICR nerve impulse conduction during voluntary cough and barium swallow and LES.
Deep inspiration and breath-hold immediately followed by BSV showed complete interruption of barium at the LES during the entire breath-hold event as shown in FIG. 5A. The ICR nerve impulse conduction is demonstrated in the schematic nerve impulse diagram of FIG. 5B and photomontage in FIG. 5A. The photos depict the inspiration followed by swallowing barium. The LES closed with deep inspiration and remains closed during the entire duration of breath-hold (>20 seconds), which appeared to hold the barium above the LES. The barium stayed above the LES until expiration.
The photomontage in FIG. 5A had a 23-second duration of and the flow of the barium was completely interrupted at the level of the LES during this entire voluntary maneuver. This result was reproduced in all subjects. In the region of the distal esophagus, diaphragm and proximal stomach are magnified using two consecutive images from a breath-hold montage that are separated by 3 seconds as shown in FIG. 6. This is an enlarged sequence of photos taken during a deep inspiration and breath-hold followed by barium swallow. The diaphragm (dotted line) appears below the level of the barium. It is believed that inspiration tonicity closure of the LES (lower arrowheads) prevented the flow of barium into the stomach. The arrows at the proximal esophagus indicate the level of barium solution. The arrowheads indicate the level of the proximal portion of the LES and the barium solution. The barium in distal esophagus showed a distinctive V-shaped tapering that suggested a cuff-like closure of the LES. The dotted line in FIG. 6 was placed above the apparent diaphragm shadow, which was clearly inferior to the distal tip of the barium solution. This result was reproducible in all subjects.
The BSV followed immediately by the LER activation, using the IRCT, showed no interruption of barium at the LES during expiratory coughs as shown in FIG. 7A. The mucosa of the vestibule of the larynx is innervated by the middle ramus of the internal laryngeal nerve. The central processes of these afferent fibers enter the medulla with the vagus nerve and terminate in restricted regions of the nucleus tractus solitaries (NTS). Stimulation of these laryngeal afferent fibers using a nebulized solution of 20% tartaric acid initiates a series of five expiratory “coughs” without inspiration, i.e., cough epoch, characteristic of the LER. The primary function of the LER is to clear the upper airway when food or fluids have entered the laryngeal vestibule. The LER appears to be inhibitory for inspiration and breathing and the associated reflex motor activations, which prevent closure of the LES during the involuntary cough epoch. Prevention of closure of the LES, during involuntary elevated IAP, may cause reflux of stomach contents in the presence of an incompetent gastric valve. The barium flow in the above standing LER cough epoch does not stop in the photomontage. The LES appears to be patent during the LER cough epoch, which prevents interruption of the flow of barium into stomach. The top record are films taken during an LER showing no closure of the LES. The nerve conduction pathways are shown in FIG. 7B.
The LER photomontage in FIG. 7A had a 13-second duration without an inspiration. The failure of the LES to close during the LER cough epoch with continuous barium flow was reproducible in all subjects.
In the one subject, who had catheters in the LES and IUS, there were corresponding increases in LES and IUS pressures associated with inspiration as confirmed by intercostals EMG activity as shown in FIG. 8. Inspiration continence reflex occurs as demonstrated by simultaneous pressure recordings of the IUS and LES with respiratory EMG of the intercostal muscles at T7-8 interspace. During slow, deep and rapid, shallow inspiration and expiration, pressure waves indicated the respiratory rate and depth dependent variation. The amplitude of the catheter pressure waves was limited by the sensitivity of the fiberoptic transducers.
The laryngeal afferent fibers to the NTS that activate the LER for airway protection or involuntary coughing are shown in FIG. 7B and do not appear to activate the inspiration continence reflex (ICR) and breathing, during the duration of the involuntary LER cough epoch. The laryngeal afferent fibers to the NTS activate the LER for airway protection or involuntary coughing and do not appear to activate the ICR and breathing, during the duration of the involuntary LER cough epoch.
The unexpected rapid closure and pressure elevation of the IUS within one second as shown in FIG. 9, after the initiation of each inspiration, can be explained by the fast conduction (30-60 m/sec) of the descending pathway in the spinal cord from the nucleus tractus solitarius (NTS) via the lateral reticulospinal tract to the neurons in the sacral autonomic nucleus at S2-4 of the spinal cord. The 25 cm long, unmyelinated, peripheral nerve component conducts at 0.5 m/sec, and takes less than one second to close the IUS. The LES closure was slightly delayed by approximately 1.5 seconds after the initiation of inspiration. This may be due to the different pathway from the NTS to the dorsal motor nucleus of X and a long peripheral, unmyelinated vagal nerve (50 cm) to the LES. Both of these closures (pressure waves) occur before the peak EMG activity, which is before the elevated intra-abdominal pressure (TAP) event in a voluntary respiratory maneuver, e.g., voluntary cough or a Valsalva maneuver.
A urodynamic tracing of a series of forceful VC in a female subject, who has moderate/severe SUI is shown in FIG. 10A. The urinary bladder was filled with approximately 300 ml of saline and intravesical and rectal pressure catheters were used.
VC did not elicit SUI despite the series of vigorous individual consecutive inhalation VC efforts. The subject showed an almost two-fold increase in average IAP with VC, each cough was preceded by a deep inspiration (inhalation). During VC, the deep inspiration that preceded VC activated the ICR and closed the IUS and resulted in a false negative result for SUI in this “moderate to severe” subject. During the involuntary reflex cough epoch as shown in FIG. 10B, the iRCT UD tracing revealed multiple urinary leaks indicated by the marked vertical lines despite lower average IAP measurements compared to VC breath-hold with maintained pressure elevation in the LES and IUS is shown in FIG. 11 corresponding with overlying voluntary contractions of the external urethral sphincter (EUS) and pelvic floor musculature. During contractions of the EUS and pelvic floor muscles, the tonicity of the LES remained relatively unchanged. Breath-hold with maintained pressure elevation in the LES and IUS corresponded with overlying voluntary contractions of the EUS and pelvic floor musculature. During contractions of the EUS and pelvic floor muscles, the tonicity of the LES remained relatively unchanged.
Breuer\'s original, classic publication reported the fundamental role of pulmonary inspiration and expiration afferent fibers and established a benchmark for respiratory physiology. Some studies further identified expiratory muscle activation as an extension and component of the Breuer reflex. It appears from a review of the literature that there have been no publications of the role of the Breuer reflex in activation of parasympathetic motor nuclei such as the dorsal motor nucleus of X for the LES or the sacral autonomic nucleus for the IUS until the recent clinical trials and pilot studies as described. These studies suggested the role of respiratory maneuvers that control the closure and pressure of the IUS and LES during inspiration and released with expiration and appeared to be coordinated and synchronized with the rate and depth of inspiration. This can refer to the circuit as the inspiration continence reflex ICR in FIG. 4B.
It has been reported that control of the LES may be due to upper and lower esophageal reflexes and diaphragmatic reflexes, i.e., crural reflex. The literature refers to transient relaxation or inhibition of the LES in association with swallowing, obstructive sleep apnea, mechanical ventilation and a negative pressure body ventilator. In animal and human studies, respiration pressure “artifacts” when using manometry have often been dismissed, ignored, or attempted to electronically filter out respiratory pressure related activity in the LES and IUS.
Animal models that require cannulation for respiration, and/or positive mechanical ventilation or anesthetized and paralyzed animals or humans may have been unobservable or over-looked activation of the ICR. Some references described a “straining crural reflex,” during the Valsalva maneuver, which caused LES closure by esophageal-diaphragmatic reflexes. In humans, using a negative pressure body ventilator (“iron lung”), the pulmonary inspiration afferent fiber activity was abolished using negative pressure to inspire for healthy, non-anesthetized subjects. This type of negative inspiration pressure ventilation and the absence of the subject\'s initiation of pulmonary inspiration afferent fibers abolished or significantly diminished manometric pressure at the LES during inspiration.
Although the pressure changes in FIG. 9 were synchronized with inspiration, the timing differences of the IUS and LES may be due to the different central and peripheral components of the IUS and LES pathways. The IUS consistently activated before the LES pressure wave with slight, but consistent, time delay. The IUS has a rapid conducting central component from the NTS to the sacral autonomic nucleus at S2-4 of the spinal cord and a short, unmyelinated peripheral nerve component (inferior hypogastric plexus). The LES has primarily a long, slow conducting, unmyelinated peripheral component via the vagus nerve (esophageal plexus). The IUS appeared to respond only to inspiration and released with expiration. During breath-hold, the elevated pressures of the IUS and LES were sustained, and volitional EUS and pelvic floor musculature contractions were observed on top of the IUS pressure wave, which were not present on the elevated LES pressure tracing as shown in FIG. 11.