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Pneumatosis intestinalis: a diagnostic dilemma A 60-year-old female presented to the emergency department with a 3-day history of abdominal pain, distension, nausea and reduced appetite with no constipation. Her medical history included severe chronic obstructive pulmonary disease (COPD) with multiple recent exacerbations. On examination, she was apyrexial with normal vital signs. She had a mildly distended abdomen with epigastric tenderness without peritonism. An erect chest radiograph showed a small amount of subdiaphragmatic air that was also noted on subsequent abdominal computed tomography. No other significant pathology was noted. It was presumed that she had a localized peptic perforation. Gastroscopy revealed mild antral gastritis. She was clinically well and so was managed non-operatively with intravenous antibiotics and observation (Fig. 1). Two months later, she re-presented with ongoing bloating, postprandial vomiting and 12 kg of weight loss. She had significant abdominal distension and mild right upper quadrant tenderness. Subsequent imaging revealed a significant pneumoperitoneum and associated pneumatosis of the small bowel (Fig. 2). Following 2 days of conservative management, her symptoms did not improve and she underwent a diagnostic laparoscopy. Intraoperatively, a small segment of pneumatosis associated with the
mesentery of her proximal jejunum was seen. The small bowel was examined in its entirety with no evidence of inflammation or perforation. No bowel was resected (Fig. 3). Her post-operative recovery was uneventful and she was discharged home on day 6. Pneumatosis intestinalis (PI) is not a disease but a radiological diagnosis.1–3 It is defined as the presence of gas in the bowel wall.4 It is indicative of systemic or local bowel wall pathological processes.1,2 Clinical presentation can range from benign to life threatening. PI is a poorly understood, rare condition with an incidence of 0.37%, an equal male to female ratio.2 There are multiple theories on its pathogenesis.1,2 The first of these is the mechanical theory.3 It is thought to be due to invasion of intraluminal bowel gas into the bowel wall.2,3 This may occur by increased intraluminal pressure forcing air into the bowel wall as with intestinal obstruction and trauma. Conversely, mucosal injury increases bowel permeability.3 Disruption of this barrier can result in the intrusion of intraluminal gas into the bowel wall. Bacterial infections, inflammatory bowel disease, bowel ischaemia and the immunocompromised state, including systemic corticosteroid therapy, have been reported to predispose to this.3,5 It is probably a combination of these factors.4
Fig. 1. Abdominal radiograph demonstrating subdiaphragmatic air and pneumatosis of the bowel.
Fig. 2. Computed tomography picture. An axial view demonstrating pneumatosis intestinalis and a significant pneumoperitoneum.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Fig. 3. Laparoscopic intra-operative photograph. Air cysts seen in mesenteric border of mid jejunum and in the mesentery. The associated small bowel was viable and was not resected.
The second is the bacterial theory.1,2 It proposes that gas-forming bacteria enter the bowel wall through mucosal defects producing intramural gas seen radiologically.2 This theory suggests that colonic bacteria cause increased hydrogen tension that supersedes blood nitrogen levels. This creates a diffusion gradient resulting in hydrogen diffusion through the mucosa. This supports the common finding of pneumatosis near mesenteric blood vessels.1 Advocates of this theory encourage the use of antibiotics. The third hypothesis is the pulmonary gas theory.3,4 Conditions such as COPD, asthma, cystic fibrosis and interstitial pneumonia have been implicated.4 It is postulated that alveolar rupture causes dissection of air through the mediastinal hilum, through the retroperitoneum and into the mesentery.3,5 This form of PI can also occur in situations of increased intrathoracic pressure such as coughing and vomiting. The clinical challenge with PI is differentiating benign and lifethreatening causes. Radiologically, life-threatening PI is associated with nodular or linear patterns of bowel wall gas.5 The presence of
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gas in the porto-venous system and a segmental distribution of gas is more likely to indicate a life-threatening cause.5 These include bowel ischaemia, toxic megacolon, volvulus, neutropenic colitis, collagen vascular disease and sepsis.1 Benign disease is typically associated with circular or ‘cystic’ air pockets.5 These include pneumatosis cystoid intestinalis, steroid use and the pulmonary causes of PI.3,4 Although these can be used as a guide, the patient’s clinical condition must be taken into account when considering the final diagnosis. PI is a radiological finding present in a spectrum of disease. Patients with benign disease can be safely treated conservatively, whereas those with significant pathology need urgent surgery. Differentiating these can often be difficult and require excellent clinical acumen.
References 1. Khailil PN, Huber-Wagner S, Ladurner R et al. Natural history, clinical pattern and surgical considerations of pneumatosis intestinalis. Eur. J. Med. Res. 2009; 14: 231–9. 2. Wu L-L, Yang Y-S, Dou Y, Liu Q-S. A systematic analysis of pneumatosis cystoids intestinalis. World J. Gastroenterol. 2013; 19: 4973–8. 3. St. Peter SD, Abbas MA, Kelly KA. The spectrum of pneumatosis intestinalis. Arch. Surg. 2003; 138: 68–75. 4. Duron VP, Rutigliano S, Machan JT, Dupuy DE, Mazzaglia PJ. Computed tomographic diagnosis of pneumatosis intestinalis. Arch. Surg. 2011; 146: 506–10. 5. Ho LM, Paulson EK, Thompson WM. Pneumatosis intestinalis in the adult: benign to life-threatening causes. AJR 2007; 188: 1604–13.
Ruben Rajan, BM Mandivavarrira Maundura, MBBS Marina Wallace, FRACS, MBBS Department of General Surgery, Fremantle Hospital, Fremantle, Western Australia, Australia doi: 10.1111/ans.13046
© 2015 Royal Australasian College of Surgeons
Pneumatosis intestinalis: a diagnostic dilemma A 60-year-old female presented to the emergency department with a 3-day history of abdominal pain, distension, nausea and reduced appetite with no constipation. Her medical history included severe chronic obstructive pulmonary disease (COPD) with multiple recent exacerbations. On examination, she was apyrexial with normal vital signs. She had a mildly distended abdomen with epigastric tenderness without peritonism. An erect chest radiograph showed a small amount of subdiaphragmatic air that was also noted on subsequent abdominal computed tomography. No other significant pathology was noted. It was presumed that she had a localized peptic perforation. Gastroscopy revealed mild antral gastritis. She was clinically well and so was managed non-operatively with intravenous antibiotics and observation (Fig. 1). Two months later, she re-presented with ongoing bloating, postprandial vomiting and 12 kg of weight loss. She had significant abdominal distension and mild right upper quadrant tenderness. Subsequent imaging revealed a significant pneumoperitoneum and associated pneumatosis of the small bowel (Fig. 2). Following 2 days of conservative management, her symptoms did not improve and she underwent a diagnostic laparoscopy. Intraoperatively, a small segment of pneumatosis associated with the
mesentery of her proximal jejunum was seen. The small bowel was examined in its entirety with no evidence of inflammation or perforation. No bowel was resected (Fig. 3). Her post-operative recovery was uneventful and she was discharged home on day 6. Pneumatosis intestinalis (PI) is not a disease but a radiological diagnosis.1–3 It is defined as the presence of gas in the bowel wall.4 It is indicative of systemic or local bowel wall pathological processes.1,2 Clinical presentation can range from benign to life threatening. PI is a poorly understood, rare condition with an incidence of 0.37%, an equal male to female ratio.2 There are multiple theories on its pathogenesis.1,2 The first of these is the mechanical theory.3 It is thought to be due to invasion of intraluminal bowel gas into the bowel wall.2,3 This may occur by increased intraluminal pressure forcing air into the bowel wall as with intestinal obstruction and trauma. Conversely, mucosal injury increases bowel permeability.3 Disruption of this barrier can result in the intrusion of intraluminal gas into the bowel wall. Bacterial infections, inflammatory bowel disease, bowel ischaemia and the immunocompromised state, including systemic corticosteroid therapy, have been reported to predispose to this.3,5 It is probably a combination of these factors.4
Fig. 1. Abdominal radiograph demonstrating subdiaphragmatic air and pneumatosis of the bowel.
Fig. 2. Computed tomography picture. An axial view demonstrating pneumatosis intestinalis and a significant pneumoperitoneum.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Fig. 3. Laparoscopic intra-operative photograph. Air cysts seen in mesenteric border of mid jejunum and in the mesentery. The associated small bowel was viable and was not resected.
The second is the bacterial theory.1,2 It proposes that gas-forming bacteria enter the bowel wall through mucosal defects producing intramural gas seen radiologically.2 This theory suggests that colonic bacteria cause increased hydrogen tension that supersedes blood nitrogen levels. This creates a diffusion gradient resulting in hydrogen diffusion through the mucosa. This supports the common finding of pneumatosis near mesenteric blood vessels.1 Advocates of this theory encourage the use of antibiotics. The third hypothesis is the pulmonary gas theory.3,4 Conditions such as COPD, asthma, cystic fibrosis and interstitial pneumonia have been implicated.4 It is postulated that alveolar rupture causes dissection of air through the mediastinal hilum, through the retroperitoneum and into the mesentery.3,5 This form of PI can also occur in situations of increased intrathoracic pressure such as coughing and vomiting. The clinical challenge with PI is differentiating benign and lifethreatening causes. Radiologically, life-threatening PI is associated with nodular or linear patterns of bowel wall gas.5 The presence of
Images for surgeons
gas in the porto-venous system and a segmental distribution of gas is more likely to indicate a life-threatening cause.5 These include bowel ischaemia, toxic megacolon, volvulus, neutropenic colitis, collagen vascular disease and sepsis.1 Benign disease is typically associated with circular or ‘cystic’ air pockets.5 These include pneumatosis cystoid intestinalis, steroid use and the pulmonary causes of PI.3,4 Although these can be used as a guide, the patient’s clinical condition must be taken into account when considering the final diagnosis. PI is a radiological finding present in a spectrum of disease. Patients with benign disease can be safely treated conservatively, whereas those with significant pathology need urgent surgery. Differentiating these can often be difficult and require excellent clinical acumen.
References 1. Khailil PN, Huber-Wagner S, Ladurner R et al. Natural history, clinical pattern and surgical considerations of pneumatosis intestinalis. Eur. J. Med. Res. 2009; 14: 231–9. 2. Wu L-L, Yang Y-S, Dou Y, Liu Q-S. A systematic analysis of pneumatosis cystoids intestinalis. World J. Gastroenterol. 2013; 19: 4973–8. 3. St. Peter SD, Abbas MA, Kelly KA. The spectrum of pneumatosis intestinalis. Arch. Surg. 2003; 138: 68–75. 4. Duron VP, Rutigliano S, Machan JT, Dupuy DE, Mazzaglia PJ. Computed tomographic diagnosis of pneumatosis intestinalis. Arch. Surg. 2011; 146: 506–10. 5. Ho LM, Paulson EK, Thompson WM. Pneumatosis intestinalis in the adult: benign to life-threatening causes. AJR 2007; 188: 1604–13.
Ruben Rajan, BM Mandivavarrira Maundura, MBBS Marina Wallace, FRACS, MBBS Department of General Surgery, Fremantle Hospital, Fremantle, Western Australia, Australia doi: 10.1111/ans.13046
© 2015 Royal Australasian College of Surgeons
