The Esophagus. Группа авторов

hypothesized that it may commence as a defensive response to something noxious that is consumed. This could be an episode of pill sticking or response to a specific food, eating in general, or an abnormal sensory response. Once incorporated into the patient’s routine, the basic pathophysiologic abnormality appears to be a reversal of the normal pressure gradient between esophageal and stomach [10]. Specifically, patients with rumination have augmentation of gastric pressure that exceeds a reduction of lower esophageal sphincter pressure. This increase in gastric pressure is thought to be achieved through contraction of the intercostal and anterior abdominal muscles, as demonstrated through EMG recordings [11]. Another contributor to the increase in gastric pressure may be decreased gastric compliance, though data demonstrating this has been inconsistent. There is also a reduction in LES pressure and thoracic pressure, helping to achieve retrograde flow of gastric content. One of the many remaining mysteries in rumination syndrome is precisely how patients accomplish it. If one asks a normal volunteer or a patient with rumination to regurgitate gastric content, with rare exceptions, it cannot be done on command.

      There may be other contributors to rumination. For example, some episodes of regurgitation are associated with an initial air swallow and belch. The belch reflex may be what achieves initial opening of the LES for the remainder of the content to flow. Conversely, the gastric strain needed to expel a supragastric belch may also contribute. Regurgitation events may also occur with an initial reflux episode, with the transient lower esophageal sphincter relaxation the facilitating event for rumination.

Psychologic factors have also been proposed as a cause of rumination syndrome, and in many studies patients with rumination score higher on anxiety testing, but how this contributes to the syndrome is unclear. One hypothesis might be that after the onset of rumination behavior, psychologic factors maintain the behavior [2]. Some data associates rumination to eating disorders [12], perhaps leading to its classification as a “Feeding and Eating Disorder” by the Diagnostic and Statistical Manual of Mental Disorders, 5th ed. [13].

Diagnosis

In most patients, the diagnosis of rumination syndrome is made by satisfying Rome criteria and taking a careful history. Indeed, treatment may be initiated on this basis. In some situations, however, objective testing is needed to confirm the diagnosis [14]. The most reliable test is performing an impedance manometry with a meal. During this study, standard baseline measurements are made fasting in addition to determining basal gastric pressure. After a meal is consumed with the catheter in place, postprandial gastric and LES basal pressures are calculated. A period of approximately 30 minutes is maintained to observe for rumination events. These events are characterized by rapid rises in gastric pressure (termed an “R” wave), reduction of LES pressure, and the appearance of gastric content entering the distal esophagus as shown in Figure 4.1. One of the keys to this testing is establishing optimal conditions by which the patient will ruminate during the study by meal choice and timing. Other testing that has been used to diagnose rumination syndrome includes gastroduodenal manometry or EMG used to detect contraction of the abdominal musculature during rumination. These tests, however, are only available in a few specialized centers. Finally, from a practical point of view, most patients will have undergone endoscopy and/or esophagography prior to manometry. These tests are normal in patients with rumination syndrome but can be useful in assessing the possibility for other disorders.

Figure 4.1 Manometric pattern of rumination syndrome. Arrow indicates periods of increased gastric pressurization. The last arrow on the right demonstrates a rumination event with gastric pressurization associated with retrograde flow on impedance (purple) proximal to the lower esophageal sphincter.

Treatment

Treatment options are listed in Table 4.3.

      Diaphragmatic breathing

The most commonly used and effective therapy for rumination syndrome is diaphragmatic breathing performed postprandially. Mechanistically, diaphragmatic breathing when performed during fed manometry has been shown to lower gastric pressure and increase LES pressure. The latter is accomplished presumably through increasing tone in the crural diaphragm. With maintenance of the normal positive pressure gradient between the LES and the stomach, the reflux of gastric content is prevented. Diaphragmatic breathing can be taught directly, with manometry using visualization of the gastric pressures for biofeedback [10] or with abdominal EMG [11] using the reduction of electrical activity in the musculature for biofeedback. Diaphragmatic breathing videos are readily available on the internet and regularly taught in disciplines such as yoga, meditation, martial arts, and singing. The concept behind this type of breathing is to extend the abdominal wall to enable inhalation rather than expansion of the chest cavity. With an increase in abdominal volume, pressure decreases (Boyle’s Law) in the abdominal cavity and, therefore, the stomach. This technique is easily taught bedside by asking the patient to place one hand on the chest and the other on the abdomen (Figure 4.2). With proper diaphragmatic breathing, the hand on the chest will stay still and the hand on the abdomen will rise. In addition to changing the symmetry of breathing, patients are asked to inhale and exhale slowly as part of the process. Slow breathing increases concentration and reduces the time available for contraction of the abdominal musculature. This can be taught initially in the supine or sitting position. Optimally, patients can perform diaphragmatic breathing in the office after consumption of a meal to assess and demonstrate effectiveness of the administered treatment. Nevertheless, several treatment sessions are often needed [3].

Table 4.3 Treatment of rumination syndrome.

Diaphragmatic breathing

Cognitive therapy/biofeedback/stress reduction

Medical therapy

Baclofen 10 mg three times daily before meals

Buspirone 5–10 mg three times daily before meals

      The long‐term efficacy of this type of breathing in controlling symptoms of rumination is not well reported, though acute administration has been shown to be effective in controlling rumination symptoms. In one study, 85% of patients were cured or improved at a one‐year follow‐up [3].

Figure 4.2 Teaching diaphragmatic breathing.

      Psychologic approaches

      Psychologic and biofeedback therapies have historically been an important part of therapy for rumination syndrome based on its putative association with eating disorders and depression. In fact, the data associating these factors to rumination are few. There are patient studies associating eating disorders with rumination [15–17]. For depression, one such study found that among patients with rumination syndrome, an increase in hypochondriasis and depression scores on the Minnesota Multiphasic Personality Inventory was recorded in 9 of 12 patients [18]. A study associating rectal evacuation disorder with rumination syndrome in 57 patients demonstrated that 93% of patients had a psychiatric comorbidity [19].