A hiatal hernia is an anatomical abnormality in which part of the stomach protrudes through the diaphragm and up into the chest. Hiatal hernias are present in approximately 15% of the population and its occurrence increases with age. Recent studies estimate that it is present in 60-65% of those over 60 years of age.
Normally, the esophagus or food tube passes down through the chest, crosses the diaphragm, and enters the abdomen through a hole in the diaphragm called the esophageal hiatus. This “hole” is a muscular tube or channel of about two to three vertebrae in length. Just below the diaphragm, the esophagus joins the stomach at the gastroesophageal junction. In individuals with hiatal hernias, the opening of the esophageal hiatus (hiatal opening) is larger than normal, and a portion of the upper stomach slips up or passes (herniates) through the hiatus and into the chest. Although hiatal hernias are occasionally seen in infants where they probably have been present from birth, most hiatal hernias in adults are believed to have developed over many years.
It is thought that hiatal hernias develop as a part of permanent positive pressure in the abdomen and negative pressure in the chest with thousands of daily unsynchronized movements of the esophagus and diaphragm. Over time, the phrenoesophageal bundles or membrane elongate, allowing the gastroesophageal junction (GEJ) to slip into the chest. Widening is currently thought of as being the result of mechanical dilatation and recurrent inflammation in the herniated stomach (often referred to as the acid chamber), which leads to periesophagitis and retraction of the diaphragmatic muscle over time. As a result of the large opening, part of the stomach “slips” into the chest. Another potentially contributing factor is an abnormally loose attachment of the esophagus to the diaphragm, which allows the esophagus and stomach to slip upwards.
Hiatal hernias are categorized as being either sliding or para-esophageal. Sliding hiatal hernias are those in which the junction of the esophagus and stomach, referred to as the gastro-esophageal junction, and part of the stomach protrude into the chest. The junction may reside permanently in the chest, but often it juts into the chest only during a swallow or if the patient is in a recumbent position. This occurs because with each swallow the muscle of the esophagus contracts causing the esophagus to shorten and to pull up the stomach through the widened diaphragm. When the swallow is finished, the esophagus relaxes and the herniated part of the stomach falls back into the abdomen. Para-esophageal hernias are hernias in which the gastro-esophageal junction stays where it belongs (attached at the level of the diaphragm), but part of the stomach passes or bulges into the chest beside the esophagus. The para-esophageal hernias themselves may remain in the chest at all times and are not affected by swallows.
A para-esophageal hiatal hernia that is large, particularly if it compresses the adjacent esophagus, may impede the passage of food into the stomach and cause food to stick in the esophagus after it is swallowed. Ulcers also may form in the herniated stomach due to the trauma caused by food that is stuck or acid from the stomach. Fortunately, large para-esophageal hernias are uncommon.
The vast majority of hiatal hernias are of the sliding type. The larger the hernia, the more likely it is to cause symptoms. When hiatal hernias produce symptoms, they may also be associated with gastro-esophageal reflux disease (GERD), to be described herein after, or its complications. GERD can occur because the formation of the hernia often interferes with the natural barrier, which prevents acid from refluxing from the stomach into the esophagus. Patients with GERD are much more likely to have a hiatal hernia than individuals not afflicted by GERD. Thus, it is clear that hiatal hernias contribute to GERD.
Normally, there are several mechanisms to prevent acid from flowing backwards (refluxing) up into the esophagus. One mechanism involves a band of esophageal muscle where the esophagus joins the stomach called the lower esophageal sphincter that remains contracted most of the time to prevent acid from refluxing or regurgitating. The sphincter only relaxes when food is swallowed so that the food can pass from the esophagus and into the stomach. The area of the sphincter normally is attached firmly to the diaphragm in the hiatus through the phrenoesophageal membrane, and the muscle of the diaphragm, also called the crura of the diaphragm, wraps around the gastroesophageal junction and the sphincter, much like a scarf. The muscle that wraps around the diaphragm augments the pressure of the contracted sphincter and the gastroesophageal junction to further prevent reflux of acid.
Another mechanism that prevents reflux is the valve-like tissue at the junction of the esophagus and stomach just below the sphincter. The esophagus normally enters the stomach tangentially so that there is a sharp angle between the esophagus and stomach. The piece of tissue in this angle, composed of esophageal and stomach wall, forms a valve that can close off the opening to the esophagus at all times and even more, when pressure increases in the stomach, for example, during eating, when the stomach is filled. It can however open to allow gastric air or contents to pass into the esophagus in a healthy subject, e.g. during belching or vomiting.
When a hiatal hernia is present, two changes occur. First, the sphincter slides up into the chest while the diaphragm remains stationery. As a result, the pressure normally generated by the diaphragm overlying the sphincter and the pressure generated by the sphincter no longer overlap, and as a result, the total pressure at the gastro-esophageal junction decreases. Second, when the gastro-esophageal junction and stomach are pulled up into the chest with each swallow, the sharp angle where the esophagus joins the stomach becomes less sharp and the valve-like effect is lost. Both changes promote reflux of acid. With the diaphragm pinching the herniated stomach and the LES closing the esophagus, an “acid chamber” may result, leading to severe esophagitis with periesophagitis and potentially ulceration and bleeding. Due to the periesophagitis, the crura also retract, leading to a widening of the diaphragmatic opening over time and worsening of the hiatus hernia.
Hiatal hernias are diagnosed incidentally when an upper gastrointestinal x-ray or endoscopy is done during testing to determine the cause of upper gastrointestinal symptoms such as upper abdominal pain. On both the x-ray and endoscopy, the hiatal hernia appears as a separate “sac” lying between what is clearly the esophagus and what is clearly the stomach. This sac is delineated by the lower esophageal sphincter above and the diaphragm below.
Treatment of large para-esophageal hernias causing symptoms requires surgery. During surgery, the stomach is accessed invasively through incisions made in the abdomen or in the chest. The stomach is pulled down into the abdomen, the esophageal hiatus is made smaller, and the esophagus is attached to the diaphragm with sutures. Although the procedure restores the normal anatomy, it is invasive, requiring weeks or even months of recovery before all normal activity may be resumed.
As will be seen subsequently, the present invention provides an alternative procedure for treating hiatal hernias. Instead of being surgically invasive, the new procedure, according to the various embodiments described herein after, may be performed transorally without the need for invasive incisions. As a result, patients are able to recover much more quickly and return to normal activity within a few days.
Gastroesophageal reflux disease (GERD) is a chronic condition caused by the failure of the anti-reflux barrier located at the gastroesophageal junction to keep the contents of the stomach from splashing into the esophagus. The splashing is known as gastroesophageal reflux. The stomach acid is designed to digest meat and other foods, and will digest esophageal tissue when persistently splashed into the esophagus.
A principal reason for regurgitation associated with GERD is the mechanical failure of a deteriorated gastroesophageal valve to close and seal against high pressure in the stomach. Due to reasons including lifestyle, a Grade I normal gastroesophageal valve may deteriorate into a malfunctioning Grade III or absent valve Grade IV. With a deteriorated gastroesophageal valve, the stomach contents are more likely to be regurgitated into the esophagus, the mouth, and even the lungs. The regurgitation is referred to as “heartburn” because the most common symptom is a burning discomfort in the chest under the breastbone. Burning discomfort in the chest and regurgitation (burping up) of sour-tasting gastric juice into the mouth are classic symptoms of gastroesophageal reflux disease (GERD). When stomach acid is regurgitated into the esophagus, it is usually cleared quickly by esophageal contractions. Heartburn (backwashing of stomach acid and bile onto the esophagus) results when stomach acid is frequently regurgitated into the esophagus and the esophageal wall is inflamed.
Complications develop for some people who have GERD. Esophagitis (inflammation of the esophagus) with erosions and ulcerations (breaks in the lining of the esophagus) can occur from repeated and prolonged acid exposure. If these breaks are deep, bleeding or scarring of the esophagus with formation of a stricture (narrowing of the esophagus) can occur. If the esophagus narrows significantly, then food sticks in the esophagus and the symptom is known as dysphagia. GERD has been shown to be one of the most important risk factors for the development of esophageal adenocarcinoma. In a subset of people who have severe GERD, if acid exposure continues, the injured squamous lining is replaced by a precancerous lining (called Barrett's Esophagus) in which a cancerous esophageal adenocarcinoma can develop.
Other complications of GERD may not appear to be related to esophageal disease at all. Some people with GERD may develop recurrent pneumonia (lung infection), asthma (wheezing), or a chronic cough from acid backing up into the esophagus and all the way up through the upper esophageal sphincter into the lungs. In many instances, this occurs at night, while the person is in a supine position and sleeping. Occasionally, a person with severe GERD will be awakened from sleep with a choking sensation. Hoarseness can also occur due to acid reaching the vocal cords, causing a chronic inflammation or injury.
GERD never improves without intervention. Life style changes combined with both medical and surgical treatments exist for GERD. Medical therapies include antacids and proton pump inhibitors. However, the medical therapies only mask the reflux. Patients still get reflux and perhaps emphysema because of particles refluxed into the lungs. Barrett's esophagus results in about 10% of the GERD cases. The esophageal epithelium changes into tissue that tends to become cancerous from repeated acid washing despite the medication.
Several open laparotomy and laparoscopic surgical procedures are available for treating GERD. One surgical approach is the Nissen fundoplication. The Nissen approach typically involves a 360-degree wrap of the fundus around the gastroesophageal junction. The procedure has a high incidence of postoperative complications. The Nissen approach creates a 360-degree moveable valve without a fixed portion. Hence, Nissen does not restore the normal movable valve. The patient cannot burp because the fundus was used to make the repair, and may frequently experience dysphagia. Another surgical approach to treating GERD is the Belsey Mark IV (Belsey) fundoplication. The Belsey procedure involves creating a valve by suturing a portion of the stomach to an anterior surface of the esophagus. It reduces some of the postoperative complications encountered with the Nissen fundoplication, but still does not restore the normal movable valve. None of these procedures fully restores the normal anatomy or produces a normally functioning gastroesophageal junction. Another surgical approach is the Hill repair. In the Hill repair, the gastroesophageal junction is anchored to the posterior abdominal areas, and a 180-270 degree valve is created by a system of sutures. The Hill procedure restores the moveable portion of the valve, the cardiac notch and the Angle of His. However, all of these surgical procedures are very invasive, regardless of whether done as a laparoscopic or an open procedure.
New, less surgically invasive approaches to treating GERD involve transoral endoscopic procedures. One procedure contemplates a machine device with robotic arms that is inserted transorally into the stomach. While observing through an endoscope, an endoscopist guides the machine within the stomach to engage a portion of the fundus with a corkscrew-like device at the hinge point. The arm then pulls on the engaged portion to create a fold of tissue or radial plication at the gastroesophageal junction. The angle of His or the valve remain unaltered. Another arm of the machine pinches the excess tissue together and fastens the excess tissue with one pre-tied implant. This procedure does not restore normal anatomy. The fold created does not have anything in common with a valve. In fact, the direction of the radial fold prevents the fold or plication from acting as a flap of a valve.
Another transoral procedure contemplates making a fold of fundus tissue near the deteriorated gastroesophageal flap to recreate the lower esophageal sphincter (LES). The procedure requires placing multiple U-shaped tissue clips around the folded fundus to hold it in shape and in place.
This and the previously discussed procedure are both highly dependent on the skill, experience, aggressiveness, and courage of the endoscopist. In addition, these and other procedures may involve esophageal tissue in the repair. Esophageal tissue is fragile and weak, in part due to the fact, that the esophagus is not covered by serosa, a layer of very sturdy, yet very thin tissue, covering and stabilizing all intraabdominal organs, similar like a fascia covering and stabilizing muscle. Involvement of esophageal tissue in the repair of a gastroesophageal valve poses unnecessary risks to the patient, such as an increased risk of fistulas between the esophagus and the stomach.
A new and improved apparatus and method for restoration of a gastroesophageal flap valve is fully disclosed in U.S. Pat. No. 6,790,214, issued Sep. 14, 2004, is assigned to the assignee of this invention, and is incorporated herein by reference. That apparatus and method provides a transoral endoscopic gastroesophageal flap valve restoration. A longitudinal member arranged for transoral placement into a stomach carries a tissue shaper that non-invasively grips and shapes stomach tissue. A tissue fixation device is then deployed to maintain the shaped stomach tissue in a shape approximating a gastroesophageal flap.
Since transoral GEFV restoration is a certain reality, it would be most desirable to be able to treat potentially related hiatal hernias in a similar manner to avoid invasive surgery altogether. The present invention addresses this and other issues.