Thoracic Surgery; anatomy, physiotherapy and managment

Physiotherapy in thoracic surgery

ANATOMY OF THE THORAX

The skeleton of the thorax is an osteocartilagenous framework within which lie the principal organs of respiration, the heart, major blood vessels, and the oesophagus. It is conical in shape, narrow apically, broad at its base

ANATOMY OF THE THORAX


and longer posteriorly. The bony structure consists of 12 thoracic vertebrae, 12 pairs of ribs and the sternum. The musculature of the thoracic cage is in two layers. The outer layer consists of latissimus dorsi and trapezius, the inner layer of the rhomboids and serratus anterior muscles. Anteriorly, the chest wall is covered by pectoralis major and minor. The intercostal muscles run obliquely between the ribs. The diaphragm forms the lower border of the thorax. It is convex upwards showing two cupolae, the right being slightly higher than the left. It is made up of muscle fibres peripherally and is tendinous centrally.

The lungs

The two lungs are basically very similar. The right lung is made up of three lobes and the left of two lobes. The lingular segment of the left lung corresponds to the middle lobe on the right. Each lobe is divided into segments. The thoracic cage is lined by the pleura. There are two layers, the parietal and visceral, which are continuous with each other and enclose the pleural space. The parietal pleura is the outer layer and lines the thoracic cavity. The visceral pleura covers the surface of the lung, entering into the fissures and covering the interlobar surfaces. The two layers are lubricated by a thin layer of pleural fluid lying within the pleural space, which, in healthy individuals, contains no other structure.

The Oesophagus

The oesophagus is a muscular tube stretching from the pharynx to the stomach. It is composed of mucosa and circular and longitudinal muscle layers. The oesophagus enters the stomach below the diaphragm at approximately the level of the eleventh thoracic vertebra.

THORACIC SURGERY

Indications for surgery

Tumour

The most common reason for pulmonary and oesophageal resection is a malignant tumour (carcinoma). A small percentage of tumours can be benign.

Lung cancers are classified into two main categories

(NICE 2005):

small-cell: 20% of all cases;

non-small-cell: 80% of all cases including squamous

cell carcinoma, adenocarcinoma and large cell

carcinoma.

Non-small-cell tumours are treated by resection if possible, if the tumour can be safely removed with clear margins and if metastatic disease is not in evidence. Smallcell cancer is virtually always widespread at diagnosis, so surgery is usually not an option.

Malignant tumours of the oesophagus are generally adenocarcinoma, especially in the lower end. They may have arisen in the cardia of the stomach and spread proximally.In the middle and upper oesophagus, squamous carcinomas predominate. Benign tumours of the oesophagus and lungs are rare.

Pneumothorax

This is a collection of air in the pleural cavity. It usually occurs spontaneously and is caused by rupture of the visceral pleura of an otherwise healthy lung. This is more common in men than women and more usual in those under 40 years of age. Patients with chronic obstructive pulmonary disease (COPD) can rupture a bulla resulting in a pneumothorax.

Other, much rarer, causes include tumour, abscess and tuberculosis (TB). Traumatic pneumothoraces can occur with blunt trauma to the chest wall, such as following a car accident or heavy fall, or from a penetrating chest wound, i.e. a stab or gunshot wound. Iatrogenic (medical in origin) pneumothoraces can occur following intravenous line insertion, after pacemaker insertion or in ventilated patients on high levels of positive end expiratory pressure (PEEP).

Empyema

Empyema is a collection of pus in the pleural cavity. The cause is commonly pneumonia, lung carcinoma or abscess, bronchiectasis or, more rarely, TB. It can occur in patients with septicaemia or osteomyelitis of the spine or ribs. Most empyemas are located basally but they can occur between two lobes.

Bronchiectasis

Bronchiectasis is a chronic lung condition in which abnormal dilatation of the bronchi occurs associated with obstruction and infection. Patients present with excessive production of purulent secretions, which become chronically infected. Bronchiectasis is generally managed medically with a physiotherapy regime and antibiotics. In some severe cases where the condition is localised to one area of the lung, lobectomy can offer some relief of symptoms.

Oesophageal perforation

Trauma and perforation to the oesophagus may result from the accidental swallowing of a foreign body (such as a dental plate). The oesophagus can rupture in cases of severe vomiting, especially if the patient tries to suppress the vomiting action. Iatrogenic perforation can occur following oesophagoscopy or surgery associated with the pharynx.

Pre-operative investigations

Patients are assessed pre-operatively in order to establish the nature of the lesion and whether they are fit for surgery.

The following investigations are commonly done.

Chest X-ray

A standard chest X-ray will be done on all patients to establish pre-operative lung status.

Computerised tomography scan

In patients with cancer a computerised tomography (CT) scan is done universally. The scan will locate the lesion accurately and show if there is invasion into surrounding structures, which determines operability. The presence of metastases in distant organs is a contraindication to surgery.

Positron emission tomography scan

In lung cancer, positron emission tomography (PET) scans are sometimes used to look for cancer in the lymph nodes in the centre of the chest or to show whether the cancer has spread to other areas. This assists with decision-making regarding adjuvant radiotherapy and surgical intervention.

Bronchoscopy/oesophagoscopy

This will establish the site of the lesion and allow biopsy or bronchial washings to be sent for histology. It can be carried out under sedation or general anaesthesia.

Pulmonary function tests

Pulmonary function tests will help the surgeon decide whether the patient can withstand lung resection. It will also provide the anaesthetist with valuable information to assess suitability for general anaesthesia.

Arterial blood gases

Arterial blood gases may be analysed routinely at some hospitals or on high-risk patients, such as those with a pre-existing lung condition

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