Disorders of the oesophagus

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22

Disorders of the oesophagus

Introduction

Benign oesophageal diseases form a small but significant part of upper GI surgeons’ workload. Most are managed by medical gastroenterologists except those likely to require surgery; then close collaboration is needed between medical and surgical specialists. Oesophageal cancer surgery is largely performed in specialised units.

Difficulty in swallowing, dysphagia, is the most common presenting symptom. Reflux oesophagitis and other peptic disorders of the lower oesophagus (often associated with hiatus hernia) and oesophageal carcinomas are the main conditions encountered. Achalasia and pharyngeal pouch are occasionally seen; oesophageal web (as in Plummer–Vinson syndrome) and leiomyomas (gastrointestinal stromal tumours, GIST) are extremely rare.

Oesophageal varices secondary to cirrhosis usually present as massive haematemesis and are usually managed with non-surgical therapy.

Carcinoma of the oesophagus

Pathology and clinical features

The oesophagus is lined by stratified squamous epithelium. Historically the majority of oesophageal malignancies were squamous carcinomas. The rest were adenocarcinomas in the lower third, probably derived from metaplastic intestinal mucosa, i.e. Barrett’s oesophageal changes. However, over the last few decades there has been a slow but steady reversal in these proportions; currently adenocarcinoma makes up 60–70% of new cases. Both forms tend to behave aggressively.

Tumours at the gastro-oesophageal junction originate from three areas: the distal oesophagus (‘type 1’), the gastric cardia (‘type 2’) or the subcardial gastric wall (‘type 3’). Oesophageal cancers may fungate into the lumen but more often infiltrate diffusely along and around the oesophageal wall. Once through the wall, the tumour invades adjoining mediastinal organs.

Difficulty in swallowing (dysphagia) is the classic symptom, but it tends to develop insidiously. Patients initially have trouble with solids but tend to compensate (liquidising their food, for example) before seeking medical advice. Later they have trouble swallowing liquids. By the time dysphagia manifests, the cancer is often incurable and lymphatic spread has already occurred to mediastinal nodes. Sometimes, involvement of other mediastinal organs, e.g. recurrent laryngeal nerve invasion or an oesophago-tracheal fistula, produces the first symptoms. Low oesophageal lesions tend to metastasise to upper abdominal nodes and the liver.

Epidemiology and aetiology

The incidence of oesophageal cancer in Western countries is relatively low compared with cancer of the colon or stomach. It accounts for about 5% of all deaths from cancer, with men at two-fold greater risk than women. The disease is usually advanced by the time of presentation, hence the mortality rate is appalling, with 70% dying within a year and only 8% surviving 5 years (see Fig. 22.1).

Oesophageal carcinoma is uncommon before the age of 50 years. At least 50% occur in the lower third and only about 15% in the upper third. Heavy alcohol intake is associated with at least 20 times greater risk and smokers have five times the risk of non-smokers; however, these risk factors classically predispose only to squamous cell carcinoma.

Since 1980, adenocarcinomas have increased by 70% relative to squamous carcinomas in many Western countries. This may be connected with the widespread use of acid-suppressing medication and possibly with dietary changes. There is no familial predisposition but people with structural and functional disorders, such as peptic oesophagitis and stricture, achalasia, oesophageal web or pharyngeal pouch, are at considerably greater risk. Areas of exceptionally high incidence have been reported in China, elsewhere in the Far East, and around the Caspian Sea. There is some evidence that a fungus which grows on food grain may be responsible. These epidemiological patterns suggest that chronic tissue irritation is an important aetiological factor. One common finding in dietary studies is an association with low fruit and vegetable intake.

Investigation of suspected oesophageal carcinoma

Dysphagia or pain on swallowing (odynophagia) in a middle-aged or elderly patient demands urgent investigation to exclude carcinoma (see Box 22.1). General physical examination is usually unrewarding except in advanced disease. In these cases, there may be signs of wasting, hepatomegaly due to metastases, a Virchow’s node in the left supraclavicular fossa or sometimes hoarseness from recurrent laryngeal nerve involvement. Gastroscopy allows direct inspection of the oesophagus using a flexible endoscope and biopsies are taken of any suspicious areas (Fig. 22.2).

Staging the cancer

Once oesophageal carcinoma is diagnosed, it is important to establish the extent of local invasion and whether metastasis has occurred to thoracic or abdominal lymph nodes, liver or peritoneum; this will determine whether potentially curative treatment is appropriate. CT scanning of chest and abdomen is the principal investigation but it often understages the disease. Staging laparoscopy for lower third tumours can show peritoneal or visceral metastases not seen on CT scan; some units employ staging thoracoscopy to assess the pleural cavity for the same reasons. Endoscopic ultrasound (EUS) demonstrates very clearly the different layers of gut wall and thus helps to delineate the tumour more accurately in length and, more importantly, depth of invasion (T stage). It also has high sensitivity and specificity for involvement of local lymph nodes and can enable biopsy of suspicious nodes in otherwise inaccessible locations (EUS-guided biopsy), enhancing the staging process and in some cases preventing unnecessary surgery. The greater the number of involved nodes, the lower the chances of surgical cure. Increasingly patients are also undergoing fluorodeoxyglucose positron emission tomography (FDG-PET), known as PET scans, which localise any cancerous tissue more accurately than CT scanning alone.

Management of carcinoma of the oesophagus

The ideal treatment would be to eliminate the cancer. In practice, this can rarely be achieved because of overt or occult spread. Even if cure is impossible, oesophageal obstruction must be relieved to allow the patient to eat and to prevent the appalling consequences of complete obstruction, namely inability to swallow even saliva.

The choice of treatment depends on the patient’s fitness and the stage, but surgical resection of the tumour is only employed when the aim is cure. Co-morbidity such as chronic lung disease or cirrhosis (often from the adverse effects of alcohol and cigarettes) may influence the decision. Cardiac fitness is assessed clinically and by electrocardiography (ECG), echocardiography, and cardiopulmonary exercise testing (CPEX). In addition, spirometry and blood gases should be performed to assess fitness for thoracotomy. If the FEV1 is less than 2 L, single lung ventilation used during thoracotomy is unlikely to be tolerated. Adjuvant therapy in addition to surgery has a role in some patients, although clinical trials are continuing to determine precise indications. Most often, chemotherapy is given alone or in combination with radiotherapy (chemoradiotherapy) before surgery (neoadjuvant therapy) in an attempt to shrink or downsize the tumour.

Historically, radiotherapy has been given as the sole form of treatment for squamous carcinoma. Intubation of the tumour was often needed before radiotherapy to prevent complete obstruction in the short term as a result of swelling. Results of this were often disappointing because of adverse local effects. Radiotherapy nowadays tends to be reserved for palliation.

For incurable patients with dysphagia, palliative procedures to restore swallowing, such as argon plasma tissue coagulation, laser treatment or stent insertion, can be effective and are preferable to major surgery, particularly if life expectancy is short.

Surgery

Once a decision has been made to operate, the choice of operation depends on the level of the lesion. In general, the aim is to remove the tumour with an appropriate safety margin, to perform a two-field lymphadenectomy (removing mediastinal and abdominal lymph nodes) and to achieve a leak-free anastomosis.

Lesions above the carina (tracheal bifurcation) are usually dealt with by a three-stage oesophagectomy known as the McKeown operation, with all stages performed at the same operation. The first stage is to mobilise the tumour and oesophagus via a right thoracotomy with the patient in the left lateral position. The second stage involves rolling the patient into a supine position and performing a laparotomy to allow the stomach to be mobilised and fashioned into a conduit. A third incision is then made in the neck through which oesophagus and tumour are delivered. The tumour is resected and the gastric conduit anastomosed to the cervical oesophagus. A cervical anastomosis is safer than an intrathoracic one, as the consequences of anastomotic leakage are less devastating.

If the tumour arises lower in the oesophagus, a two-stage Ivor Lewis operation