Gastrointestinal Perforation

Gastrointestinal perforation may occur at any anatomical location from the upper oesophagus to the anorectal junction.

Delay in resuscitation and definitive surgery will progress rapidly into septic shock, multi organ dysfunction, and death, hence it should be one of the first diagnoses considered and excluded in all patients who present with acute abdominal pain.

In this article, we shall look at the causes, clinical features, and management of gastrointestinal perforation.

Aetiology

The most common causes of gastrointestinal (GI) perforation are peptic ulcers (gastric or duodenal) and sigmoid diverticulum.

Inflammatory or Ischaemic

• Chemical
  • Peptic ulcer disease
  • Foreign body (e.g. battery or caustic soda)

By Jiri.pekhart [CC BY-SA 3.0], via Wikimedia Commons

Figure 1 – Endoscopic image of colorectal adenocarcinoma

• Infection
  • Diverticulitis
  • Cholecystitis
  • Meckel’s Diverticulum
• Ischaemia
  • Mesenteric ischaemia
  • Obstructing lesions (e.g. cancer*, bezoar, or faeces (sterocoral)), resulting in bowel distension and subsequent ischaemia and necrosis
• Colitis
  • Toxic Megacolon (e.g. Clostridum Difficile or Ulcerative Colitis)

 *GI malignancies are also capable of local invasion through the bowel wall leading to perforation.

Traumatic

• Iatrogenic
  • Recent surgery (including anastomotic leak)
  • Endoscopy or overzealous NG tube insertion
• Penetrating or blunt trauma
  • Shear forces from acceleration-deceleration or high forces over small surface area (e.g. a handle bar)
• Direct rupture
  • Excessive vomiting leading to oesophageal perforation (Boerhaave Syndrome)

Clinical Features

The main feature of gastrointestinal perforation is pain. Typically this is rapid onset and sharp in nature. Patients are systemically unwell therefore may also have associated malaise, vomiting, and lethargy.

On examination, patients will look unwell and often have features of sepsis. On examining their abdomen, they will have features of peritonism, which may be localised or generalized (a rigid abdomen).

If they are peritonitic throughout their abdomen, then this implies generalised contamination and they will almost always need urgent surgery.

Thoracic Perforation

Any thoracic region perforation (such as a oesophageal rupture) will present with pain, ranging from chest or neck pain to pain radiating to the back, typically worsening on inspiration. There may be associated vomiting and respiratory symptoms.

On examination, auscultation and percussion may reveal signs of a pleural effusion, with the potential for palpable crepitus. This is discussed in more detail here.

Differential Diagnosis

The list of potential differentials is vast. Important differentials to consider are acute pancreatitis, myocardial infarction, tubo-ovarian pathology, or a ruptured aortic aneurysm.

Investigations

Laboratory Tests

Any patient with an acute abdomen will require routine baseline blood tests, including G&S.

Raised WCC and CRP are common features, dependent on timing and degree of contamination, and amylase is often mildly elevated in perforation (although non-specific).

A urinalysis should also be routinely performed to exclude both renal and tubo-ovarian pathology.

Imaging

Imaging is vital to confirm the suspected diagnosis (by demonstrating air outside the gastrointestinal tract).

A plain film erect chest radiograph (eCXR) can show free air under the diaphragm. Pneumomediastinum or widened mediastinum may also be present if the perforation is thoracic in origin.

The gold standard for diagnosis of any perforation is with a CT scan, confirming any free air presence and suggesting a location of the perforation (as well as a possible underlying cause).

An abdominal radiograph (AXR) can show signs of perforation, however CT imaging has made the role of the AXR limited. Features on AXR (Fig. 2) include:

• Rigler’s sign – both sides of the bowel wall can be seen, due to free intra-abdominal air acting as an additional contrast
• Psoas sign – loss of the sharp delineation of the psoas muscle border, secondary to fluid in the retroperitoneum

*The sensitivity in detecting perforation on eCXR is around 70%, meaning 3 out of every 10 patients with a gastrointestinal perforation will have no signs on plain film radiograph

Adapted from work by Scott1751 and Clinical_Cases [CC BY-SA 2.5], via Wikimedia Commons

Figure 2 – Radiographic evidence of pnuemoperitoneum a) Free air under the diaphragm; and b) Rigler’s sign

Management

The management of any suspected GI perforation warrants an early assessment and resuscitation, rapid diagnosis, and early definitive treatment.

Broad spectrum antibiotics should be started early, especially in patients deemed to need surgery for contamination. Patients should be placed nil by mouth and an nasogastric tube considered. Provide adequate IV fluid support and appropriate analgesia.

Following this standard initial approach, management becomes highly individualised, taking into account the site of perforation and patient factors. However, most patients with a perforated viscus will require theatre for repair and control of contamination.

Surgical Intervention

The key aspects of any surgical intervention for a GI perforation are:

• Identification and (where possible) management of underlying cause 
• Appropriate management of perforation, such as:
  • Repairing perforated peptic ulcer with an omental patch
  • Resecting a perforated diverticulae (e.g. via a Hartmann’s procedure)
• Thorough washout

Conservative Management

Select physiologically well patients may be managed conservatively, including patients with:

• Localised diverticular abscess / perforation* with only localised peritonitis and tenderness, and no evidence of generalised contamination on CT imaging

• Patients with a sealed upper GI perforation on CT imaging without generalised peritonism
• Elderly frail patients with extensive co-morbidities who would be very unlikely to survive surgery

*An estimated size less than 5cm on CT scan is an accepted cut off for conservative treatment in these patients, who may respond to antibiotics alone or may be amenable to guided percutaneous drainage

Complications

The most important and severe complications of a GI perforation are infection (peritonitis and sepsis) and haemorrhage, with incidence depending on the site involved.

Appendix – Surgical Techniques in GI Perforation

The surgical technique employed varies depending on the pathology and the anatomical location involved. The most important aspect of any surgery for perforation however remains the intra-operative washout

• Any stomach or duodenum perforation can be accessed typically via an upper midline incision (also can be done laparoscopically), and a patch of omentum is tacked loosely over an ulcer which would otherwise be difficult to oversew due to tissue inflammation
  • All gastric ulcers should be biopsied to exclude malignancy
• Small bowel perforations can be accessed via a midline laparotomy; small perforations can be oversewn if the bowel is viable, yet any doubt about condition of bowel should lead to resection and primary anastomosis +/- stoma formation
• Large bowel perforations can be accessed via midline laparotomy; anastomosis in the presence of faecal contamination and an unstable patient is not recommended, so a resection with stoma formation is the preferred option