Specialist oesophagogastric emergencies

Iatrogenic perforation of the oesophagus

Iatrogenic damage to the oesophagus leading to full-thickness disruption occurs from within in 60–70% of cases, such as during endoscopic instrumentation, or from without, such as during paraoesophageal or thoracic lung surgery. Diagnostic flexible endoscopy remains a safe procedure when performed by appropriately trained individuals. However, the sheer numbers of endoscopies performed have led to an overall increase in perforations. Flexible endoscopy (0.03% perforation risk) has almost totally replaced rigid oesophagoscopy (0.11% perforation risk). There are very few indications to perform a rigid endoscopy and there is no longer a role for food bolus removal with rigid oesophagoscopy given the safer flexible endoscopic techniques.

Intubation of the oesophagus can cause proximal perforation, with the risk increased by hyperextension of the neck and the presence of arthritic cervical osteophytes or an oesophageal diverticulum. However, in 75–90% of diagnostic perforation cases trauma is sustained to the distal oesophagus, often in conjunction with an abnormality.

The majority of oesophageal full-thickness perforation occurs during endoscopic interventions ( Table 16.1 ). Balloon or Savary–Gilliard dilatation of strictures accounts for most perforations. This risk is increased in patients with a malignant stricture, previous radiotherapy, or chemotherapy. The risk from self-expanding metal stents for palliating malignant strictures is lower. Stents placed for other reasons such as attempted treatment of anastomotic disruption or benign strictures can erode through the oesophagus at other sites. Stents not placed for palliation of malignancy should therefore be removed in a timely manner to avoid such situations. Endoscopic mucosal and submucosal resection for dysplastic or intramucosal adenocarcinoma also carries a perforation risk of up to 2%.

Treatment for achalasia with pneumatic dilatation has a higher perforation risk than standard balloon dilatation due to the higher pressures and larger balloon size. The risk can be minimised by always starting at the smallest balloon size (30 mm) for the initial dilatation. Per oral endoscopic myotomy (POEM) is a newer treatment for achalasia, with some evidence for its consideration alongside surgical myotomy and pneumatic dilatation. POEM has its own perforation risk.

All other modalities of oesophageal intubation including nasogastric tube placement, transoesophageal echocardiogram, and inadvertent oesophageal placement of an endotracheal tube can result in oesophageal perforation. In contrast to some guidelines advocating blindly pushing through a food bolus, caution should be exercised in performing this manoeuvre unless it is known for certain that the distal lumen is not obstructed by a stricture, either benign or malignant. Pushing a food bolus distally should ideally only be done if the endoscope can pass the bolus and confirm there is no distal obstruction, although often this is not possible.

Mortality rates have improved over the years, but iatrogenic perforation of the oesophagus can still be a life-threatening condition. A case review of 75 patients with iatrogenic perforation reported a not insubstantial mortality rate of 19%. Prevention is the best solution, with continued efforts to increase awareness and training likely to reduce the incidence.

Spontaneous perforation of the oesophagus

Boerhaave’s syndrome is characterised by barogenic trauma in an otherwise normal oesophagus, leading to immediate and gross gastric content contamination of the mediastinum and often of the pleural cavity. The ensuing chemical and septic mediastinitis can precipitate a rapid deterioration in the patient’s condition. The actual degree of damage to the oesophagus and ensuing contamination can vary considerably. The disruption of the oesophageal wall is associated with a sudden increase in intra-abdominal pressure. In most cases this is related to vomiting or retching, although weightlifting, parturition, defecation, the Heimlich manoeuvre, and status epilepticus have all been implicated in the past. The fact that vomiting is common but oesophageal perforation is not suggests as yet unrecognised anatomical or pathological abnormalities may exist. In apparent ‘spontaneous perforation’, an underlying cause such as malignancy, peptic ulceration, or infection is discovered in up to 20% of cases. Eosinophilic oesophagitis can also predispose to oesophageal perforation, spontaneously after vomiting to dislodge an impacted food bolus, or after endoscopic intervention. The mechanism of a spontaneous perforation differs from that of a Mallory–Weiss tear, as the forces resulting in the latter are shearing in nature as opposed to the barogenic force in a perforation.

The most common location for a spontaneous perforation is just above the oesophagogastric junction in the left posterolateral position. The perforation usually occurs in a solitary location, 1–8 cm long, with the disruption longer on the mucosal side than the adventitial side. In cases where the pleura is disrupted, this can occur at the time of the barogenic event or subsequently as a result of gastric acid erosion, exacerbated by intrathoracic pressure.

Penetrating injuries

Penetrating injuries of the oesophagus are rare but associated with significant morbidity and mortality. The overwhelming majority of penetrating injuries to the oesophagus are associated with significant injury to the surrounding tissues and organs. The oesophageal injury can be overlooked at the time of initial presentation when the management of more immediately life-threatening vascular, cardiac, or lung injuries takes precedence. However, a delay in identifying and managing such oesophageal injuries increases the morbidity and mortality from the injury. Injury should be suspected in any gunshot or knife wound to the cervical or mediastinal regions. The degree of disruption is dependent on the type of weapon involved and the velocity of any projectile. High-velocity projectiles will cause far greater damage due to the cavitation effect while lower velocity projectiles might result in more limited injury. The injury severity can be graded according to the American Association for the Surgery of Trauma.

Penetrating injuries from within are much less common, with causes including ingestion of sharp objects, fish or meat bones, and swallowed dentures ( Fig. 16.1 ). The mechanism of penetrating injuries from within more often follows a pattern similar to iatrogenic or spontaneous perforation.

Blunt trauma

Blunt trauma that causes significant injury to the oesophagus is rare. The mechanism is almost exclusively high-impact trauma such as road traffic collisions and it is often associated with more immediately life-threatening injuries of the airway, heart, or lungs. The cervical oesophagus is at risk from severe flexion-extension of the neck or from impact of the neck or upper chest on the steering wheel. The fixed points of the oesophagus at the cricoid, carina, and pharyngo-oesophageal junction are most susceptible to rapid deceleration traction laceration. Barogenic damage can occur after a sudden rise in intra-abdominal pressure from compression against a closed glottis. Secondary injury to the oesophagus can occur following interruption of vascular supply.

Blast injuries to the oesophagus are exceedingly rare. There are few reports in the literature.

Plain radiography

The typical findings on plain chest radiography are subtle and dependent on the site and the time interval following the insult. These are documented in Box 16.2 and Fig. 16.2 . A plain abdominal radiograph may help to exclude a perforated intra-abdominal viscus.

Computed tomography

Urgent CT is the first-choice imaging modality and should not be delayed when the diagnosis is suspected. With the advent of modern scanners, CT with intravenous contrast should be sensitive enough to identify the site of an oesophageal perforation, although some radiologists still prefer to also administer oral contrast. In an intubated patient, the sensitivity of CT for spontaneous perforation is increased by placing a nasogastric tube just past the cricopharyngeus to run in a small amount of contrast media, although in practice this is now rarely performed ( Fig. 16.3 ). It is useful to evaluate images with a radiologist who specialises in (upper) gastrointestinal radiology if at all possible. CT is especially helpful in multi-trauma and critically ill patients with an atypical presentation.

In combination with complex interventional radiology, CT has also revolutionised the management of intrathoracic collections. It plays a vital role in assessing the progress of patients, be that after non-operative or operative management.

Contrast radiography

Oral water-soluble contrast radiography ascertains the site, the degree of containment, and the degree of drainage of the perforation ( Fig. 16.4 ). Aqueous agents are rapidly absorbed, do not exacerbate inflammation, and have minimal tissue effects. However, false-negative results in 27–66% and the limited applicability to a collapsed, unwell patient have downgraded their usefulness. In assessing healing of a perforation, the author would advocate the use of dilute barium to ascertain the presence or absence of any ongoing leak if water-soluble contrast studies were negative.

Upper gastrointestinal endoscopy

Endoscopic assessment by an experienced endoscopist excludes the diagnosis if normal, influences management if underlying pathology is discovered, and facilitates the placement of a nasojejunal tube to allow enteral feeding ( Figs. 16.5 and 16.6 ). Endoscopy can be performed in the sickest of patients, in the critical care unit, or in theatre, when other injuries or instability of the patient preclude radiological assessment. It is often safest to perform endoscopy in suspected spontaneous perforation under a general anaesthetic with the patient intubated. This can allow for positive-pressure ventilation to reduce the risk of cardiorespiratory embarrassment by air insufflation into the mediastinum and pleural spaces. This risk is minimised by introducing the endoscope without insufflation and using suction to drain fluid from any cavity. It is important to be prepared for rapid chest decompression if chest drains are not already in situ. Otherwise endoscopy should be performed with an anaesthetist present and ready to intubate should the patient become unstable.

Other investigations

Thoracocentesis of gastric contents is diagnostic – a pH of less than 6.0, a high amylase, or microscopic squamous cells in the fluid can also confirm oesophageal perforation. Swallowed or injected oral/nasogastric dyes, such as methylene blue, may be diagnostically useful if a communicating drain is in situ. Dye staining can, however, be troublesome in the operative field if surgery is subsequently required.

Non-operative management

Non-operative, endoscopic, and minimally invasive operative management have all been shown to be safe and feasible in carefully selected patients who have either been diagnosed with minimal contamination and no mediastinitis or with a contained perforation. It may also be considered in those with a delayed diagnosis who have demonstrated tolerance. Non-operative treatment is not ‘conservative’. Patients require intensive observation and a low threshold for intervention, with 20% of patients requiring aggressive surgical salvage.

Non-operative treatment comprises observation in a critical care environment with patients kept nil by mouth and preferably fed enterally, if necessary via a feeding jejunostomy. A nasogastric tube should be placed under endoscopic and/or radiological assistance past the perforation to decompress the stomach and to limit refluxate, especially in distal oesophageal perforations. Contrast radiology, endoscopy, and CT are used to monitor the status of the perforation. Collections should be drained. The timing of investigations is guided by the clinical condition of the patient, but weekly contrast or CT studies are not unreasonable. All patients should be given broad-spectrum intravenous antibiotics, and antifungal and antisecretory agents.

Iatrogenic cervical perforations are usually contained and thus managed non-operatively with percutaneous drainage of collections where necessary. Any resulting oesophagocutaneous fistulas heal rapidly in the absence of distal obstruction. Operative prevertebral lavage, primary closure, and drainage via a left lateral incision anterior to the sternocleidomastoid is occasionally required and is well tolerated by even critically ill patients.

Criteria have been developed to aid the selection of suitable patients for non-operative management. ^{, ,} These are detailed in Box 16.4 . Other factors requiring consideration include control of the perforation, excluding underlying oesophageal disease, absence of septic shock, and the ability to change the management strategy promptly if required. Case series applying these criteria demonstrate a mortality rate between 0% and 24%, but numbers are small and results are skewed by both selection and publication bias.

Adjuncts to non-operative management

An endoluminal approach can be used to support patients undergoing non-operative management and can replicate some of the principles of open surgery. This is pertinent in patients where the benefits of surgical exploration are outweighed by the risk and the ultimate outcome (in advanced or perforated cancer, for instance), or in patients in whom the defect is small, clean, and easily dealt with at the time of injury. All endoscopic approaches are technically difficult and should not be attempted by inexperienced operators unable to deal with the consequences of their actions. The mediastinitis, cardiorespiratory compromise, and sepsis accounts for mortality in these patients and not the actual underlying defect. Any endoluminal therapy should not be viewed as the sole definitive solution: ongoing active management is required. In many situations where endoluminal stents or clips have been used, it is apparent that the perforation would have healed with the above non-operative measures and without the endoluminal adjunct. This has to be borne in mind, especially when stents themselves can cause significant complications, including erosion and bleeding.