Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 443

Achalasia is an oesophageal motor disorder of unknown aetiology, associated with incomplete or absent swallow‐induced LOS relaxation together with disordered oesophageal contractile activity.³³ Inflammation of the myenteric plexus is an early histological finding, followed by ganglion loss and neural fibrosis. The condition typically presents with dysphagia for both liquids and solids, although weight loss, regurgitation, and aspiration may also be presenting symptoms, particularly in the elderly. Conversely, chest pain is reported less often in older than in young patients.

A barium swallow may show impaired peristalsis, delayed emptying, and dilatation of the oesophageal body (the latter more characteristic in the elderly than the young), with ‘bird’s beak’ or ‘rat’s tail’ tapering at the LOS (Figure 17.2). At manometry, the resting LOS pressure may be high or within the normal range, but LOS relaxation on swallowing is either absent or incomplete. Contractions of the oesophageal body can be either absent (type I) or simultaneous (type II), or there may be premature distal oesophageal contractions (type III)³³ (Figure 17.3). Endoscopy (and sometimes endoluminal ultrasound and/or computed tomography) must be performed to exclude ‘pseudo‐achalasia’, especially in the elderly; this entity presents with features of achalasia but is due to carcinoma of the distal oesophagus or cardia. A short history of symptoms and disproportionate weight loss is particularly suggestive of this diagnosis.

Figure 17.2 Barium swallow in a patient with achalasia, demonstrating a dilated oesophagus with tapering at the distal end.

Pneumatic dilatation and surgical myotomy (now usually performed laparoscopically) represent the most efficacious treatments for achalasia, and each has a very high rate of treatment success in type 1 and 2 achalasia. Each is associated with a 1% perforation rate even in experienced hands; and while pneumatic dilatation is associated with less morbidity and cost, it may need to be repeated.³⁴ In recent years, the technique of peroral endoscopic myotomy (POEM) has emerged and may allow close calibration of myotomy to the manometric findings – a useful asset in the treatment of type 3 achalasia, which should otherwise be managed laparoscopically.³³ In general, either pneumatic dilatation or laparoscopic myotomy is well tolerated in the elderly; in a consecutive series of 51 patients age ≥65 undergoing the latter procedure, there were no deaths, few complications, and a median hospital stay of 3 days.³⁵ Both pneumatic dilatation and POEM can induce reflux symptoms in a minority; this can be pre‐empted with laparoscopic myotomy by performing an anti‐reflux procedure concurrently.

For the frail elderly patient with achalasia, endoscopic injection of botulinum toxin into the LOS represents an alternative and safe therapy. Two‐thirds report improvement in dysphagia after this procedure, although the majority relapse within one year, and repeat treatments become progressively less effective.³³ Pharmacological therapy to reduce LOS pressure (nitrates, calcium channel antagonists, or phosphodiesterase type 5 inhibitors) is of limited efficacy (possibly even less in the elderly than the young), requires frequent dosing, and is associated with frequent adverse effects, so it cannot be recommended.

Patients with achalasia have an increased risk (estimated as 16‐fold) of squamous cell carcinoma of the oesophagus, but as the absolute risk is small, the cost‐benefit ratio of surveillance endoscopy appears unlikely to be favourable.³⁶ Occasionally, patients with achalasia have persistent dysphagia despite therapy, together with a tortuous, dilated oesophagus that empties poorly; in these circumstances, esophagectomy may be required.