Hiatal hernias occur when contents of the abdominal cavity protrude through the esophageal hiatus of the diaphragm. Factors that contribute to the development of a hiatal hernia include an enlargement of the esophageal hiatus due to developmental defects, an increased abdominal thoracic pressure gradient, and the depletion of elastic fibers in the phrenoesophageal membrane with aging. There are four different types of hiatal hernias and management varies depending on the type.
Type I, also known as a sliding hernia, is a simple displacement of the gastroesophageal junction into the thoracic cavity. The stomach remains in the abdominal cavity. This is the most common type of hiatal hernia, accounting for about 95% of all hiatal hernias. Types II-IV are classified as paraesophageal hernias. Type II occurs when the gastroesophageal junction maintains its position but the gastric fundus herniates through the diaphragmatic hiatus. Type III has both the gastroesophageal junction and the stomach herniate above the diaphragm. When more than 30% of the stomach is herniated into the thoracic cavity, it is termed a “giant” paraesophageal hernia. A patient has a type IV hernia when other organs, such as the colon, in addition to the stomach herniate above the diaphragm.
Most type I hernias do not cause any symptoms, but when large, they can cause gastroesophageal reflux disease. Most can be managed medically. Those that are refractory to medications do require surgery, most commonly a Nissen fundoplication. Similarly, paraesophageal hernias are mostly asymptomatic and are often found incidentally on imaging. Mild symptoms include chest and epigastric pain, dysphagia, early satiety, post prandial shortness of breath and chronic anemia secondary to erosions of gastric mucosa from gastric distension. Life threatening conditions can occur if the stomach has volvulized. This can lead to serious consequences such as an acute gastric obstruction with ischemia, strangulation and perforation.
Although there is no consensus regarding surgical management of asymptomatic paraesophageal hernias, most surgeons would agree that even mildly symptomatic paraesophageal hernias should be repaired. In the past, there was a push to repair asymptomatic paraesophageal hernias in order to avoid having to perform an emergency operation in the setting of an acutely incarcerated stomach. However, research has shown that episodes of incarceration and strangulation are rare after 60 years of age and that even if emergency surgery is required, the operation is not quite as difficult as may be assumed. In contrast, those who argue for the surgical treatment for asymptomatic paraesophageal hernias would contend that there is a low but still present risk for life threatening complications, there is an associated increased mortality with an emergency surgery and that the ability to perform a minimally invasive procedure is higher in an elective setting. Further data is necessary to evaluate this topic.
Once a paraesophageal hernia has been diagnosed and the decision has been made to go forward with surgery, there are certain tests that should be performed. An esophagram will help define the anatomy and partially asses esophageal motility, which could affect surgical management. If the esophagram does document esophageal motility, esophageal manometry should be performed as well. An upper endoscopy is also commonly performed which can help assess the anatomy and evaluate for other concerns, such as esophagitis.
Approaches to repairing paraesophageal hernias include transthoracic (typically open via the left chest), open transabdominal and laparoscopic transabdominal. Thoracoscopic hiatal hernia repairs have been described in the pediatric population, but are uncommon. A minimally invasive approach should be performed by expert laparoscopic surgeons with familiarity with foregut anatomy. Studies have shown that laparoscopic repair has a significantly decreased mortality rate of 0.5% as well a decreased length of hospital stay of about 3 days. The important steps to a paraesophageal hernia repair are outlined below.
Excision of the hernia sac: The contents of the hernia sac are first reduced into the abdominal cavity. The hernia sac often extends high up into the mediastinum. There is an avascular plane that allows the sac to be bluntly dissected off of the intrathoracic structures with minimal bleeding. Once the sac has been mobilized, it is excised down to the anterior wall of the esophagus and around the gastroesophageal junction. During this step, it is important to identify the vagal nerves and to be careful not to injure them during excision of the sac.
Mobilization of the esophagus: The esophagus should be mobilized so that at least 3cm of the distal esophagus lies in the abdomen. This is to avoid recurrence. Usually, this is able to be achieved with high mediastinal dissection. If mobilization is inadequate, an esophageal lengthening procedure should be performed, typically with a Collis gastroplasty. A 48Fr bougie (or similar size relative to the patient’s size) is passed into the stomach. The stomach is then divided parallel to the bougie on the side of the greater curvature 5cm past the gastroesophageal junction to perform a wedge gastrectomy which will provide an additional 5cm of length to the esophagus.
Closure of the crura: The enlarged diaphragmatic hiatus is closed primarily with suture for a tension free repair. There have been no long term studies that have demonstrated the greater efficacy or lower recurrence rates with mesh repair although short terms trials have supported the use of mesh. When mesh is used, it typically is used as an onlay over crura that have been closed primarily. Debate also continues on the type of mesh to employ.
Fundoplication: Most studies describe a fundoplication as a routine step in paraesophageal hernia repairs; however, this is not necessarily routinely performed by all surgeons. There is a high rate of reflux following a paraesophageal hernia repair given the extensive hiatal dissection and the disruption of typical hiatal anatomy. However, many patients with paraesophageal hernias have a degree of esophageal dysmotility and risk potentiation of this by a fundoplication. Thus, whether or not a fundoplication is performed and what type of fundoplication is utilized is often dependent on the patient’s symptomatology, anatomy, and physiology.
Mortality rate following an elective open hiatal hernia repair has been quoted at 1.0-2.7%. Laparoscopic elective repairs have mortality rates as low as 0.57%. The difference is likely due in part to the patient population who more commonly develops hiatal hernias; they are older and have associated comorbid medical conditions which can adversely affect their ability to recover from a complex operation. Fortunately, many studies have shown that with a minimally invasive approach, patients have a shorter length of hospital stay and quicker recovery time thus making laparoscopic repair a feasible option.
Common complications following this procedure include recurrent herniation, reflux and dysphagia. Initial studies that compared laparoscopic to open repairs found that laparoscopic repairs had higher rates of recurrence, as high as 40% whereas open repairs were associated with a 10% recurrence rate. Subsequent studies did confirm a higher anatomic and radiographic rate of recurrence after a minimally invasive repair; however, it was also demonstrated that the long term quality of life reports and the presence of symptoms was actually equivalent to that of an open repair. This has led most of the surgical community to conclude that the benefits reaped from a laparoscopic repair outweigh the higher long term recurrence rates as the actual clinical outcomes are comparable.
As discussed before, the addition of an antireflux procedure to a hiatal hernia repair is often determined by the surgeon. Patients who develop reflux following a hiatal hernia repair may require a second operation for an antireflux procedure if their reflux is unable to be managed with medication. Conversely, those who did have an antireflux procedure during their hiatal hernia repair are at risk for developing dysphagia post-operatively and may require a second operation to loosen or even takedown their fundoplication.
A minimally invasive approach has now become the standard of care in elective hiatal hernia repairs. It is a challenging operation and should only be performed by surgeons who have been specially trained in this procedure. It has proven to be as durable as open repairs and has been shown to minimize complication rates and improved recovery time.
Written by Ann Y. Chung, MD