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Peritoneal encapsulation as a cause for recurrent abdominal pain in a 16-year-old male A 16-year-old male presented with centralized abdominal pain and non-bilious vomiting. He had suffered many similar episodes since the age of 4 years, resulting in several hospital admissions and a diagnosis of recurrent abdominal migraine. He had no prior operative history. Initial abdominal examination revealed central and left lower quadrant tenderness with minimal distension, though the abdominal distension worsened following admission. There was no evidence of bowel obstruction on plain radiography and all blood tests were unremarkable. A subsequent abdominal ultrasound revealed a normal superior mesenteric artery/vein relationship. Multiple, dilated bowel loops were noted centrally, and the bowel wall appeared thickened. An abdominal computerized tomography (CT) identified a high-grade small bowel obstruction, with two areas of abrupt transition in the central abdomen suggestive of an internal hernia (Fig. 1). Laparotomy revealed a peritoneal sac extending from the lateral edge of the proximal jejunal mesentery to the medial edge of the descending colon mesentery (Fig. 2). The sac extended cranially to the left paraduodenal recess, with a narrowed neck inferomedially, and contained loops of viable small bowel. Following delivery of the small bowel, the majority of the sac was excised, with the remaining
fragment secured to the retroperitoneum to obliterate any residual opening. The post-operative course was uneventful and the patient was discharged after 7 days. Histological examination of the peritoneal sac demonstrated a layer of fibrous tissue focally covered by prominent mesothelium, with granular pigments suggestive of hair. The possibility of a previous localized perforation was suggested. Peritoneal encapsulation is a rare cause of small bowel obstruction.1,2 Also referred to as abdominal cocoon or idiopathic encapsulating peritonitis, the condition features total or partial encapsulation of the small bowel within a fibro-collagenous membrane.1,3 The condition is often diagnosed incidentally.1 Peritoneal encapsulation may be either a primary or secondary phenomenon. Though the pathogenesis of primary peritoneal encapsulation remains poorly understood, it has been suggested that the peritoneal sheath is derived from the yolk sac lining following reduction of the midgut into the coelomic cavity.4 Secondary causes include retrograde menstruation, ventriculo-peritoneal shunts, peritoneal dialysis, abdominal tuberculosis, sarcoidosis, cirrhosis and systemic lupus erythematosus.5–7 Subclinical peritonitis is thought to be another secondary cause, and is suspected in the case presented above. In endemic areas, tuberculosis is a particularly common cause for peritoneal encapsulation, with Singh et al. reporting 50%
Fig. 1. Abdominal computerized tomography (CT) demonstrating the two transition points at the entry to the peritoneal sac (arrow), with contained small bowel loops.
Fig. 2. Intra-operative photograph of the peritoneal sac (arrow). The sac is demonstrated cranially, with contained small bowel loops. The free small bowel loops are situated caudally.
© 2014 Royal Australasian College of Surgeons
ANZ J Surg •• (2014) ••–••
2
of their patients as having proven peritoneal encapsulation of tubercular aetiology.5 The condition may affect both paediatric and adult populations. Patients typically present with features of small bowel obstruction, including abdominal pain, vomiting and abdominal distension.6 Pain is caused by compression or kinking of the intestine within the sac.5 As illustrated in the above case, patients may experience such symptoms intermittently for months or even years before definitive diagnosis. Suggestive physical examination findings include fixed asymmetrical abdominal distension and differences in consistency upon palpation of the abdominal wall.6 Preoperative diagnosis of this condition is difficult.6 Reports of the effectiveness of contrast studies, including the presence of a ‘cauliflower sign’, are variable.8 Ultrasound and CT have been suggested as the more specific imaging modalities.5 A mass of small bowel loops may be evident on CT, with intestinal dilatation and an obvious transition point.6 Symptoms and radiological findings may be very similar to paraduodenal or other types of internal herniae, making it challenging to differentiate between these diagnoses preoperatively.5,9 In the setting of obstruction, operative intervention is required. A laparotomy is more commonly performed, though successful laparoscopic excision has been described.3 The operative principles include excision of the membrane, lysis of adhesions, avoidance of bowel injury and resection of non-viable bowel segments.3 This last step is rarely necessary, though cases of ischaemic bowel within a peritoneal sac have been reported. Sahoo et al.2 described gangrenous ileum, caecum, appendix, ascending colon and part of transverse colon all contained within the sac, requiring resection and ileocolic anastomosis. The long-term outcomes for patients with peritoneal encapsulation are generally excellent.5 For patients presenting with small bowel obstruction, in the absence of more common aetiologies, peritoneal encapsulation should be kept on the surgeon’s list of differential diagnoses. Awareness of this rare condition may lead to appropriate investigations, thus avoiding a delayed diagnosis.
Images for surgeons
References 1. Mordehai J, Kleiner O, Kirshtein B, Barki Y, Mares A. Peritoneal encapsulation: a rare cause of bowel obstruction in children. J. Pediatr. Surg. 2001; 36: 1059–61. 2. Sahoo S, Gangopadhyay A, Gupta D, Gopal S, Sharma S, Dash R. Abdominal cocoon in children: a report of four cases. J. Pediatr. Surg. 1996; 7: 987–8. 3. Ertem M, Ozben V, Gok H, Aksu E. An unusual case in surgical emergency: abdominal cocoon and its laparoscopic management. J. Minim. Access Surg. 2011; 7: 184–6. 4. Rajagopal A, Rajagopal R. Conundrum of the cocoon. Report of a case and review of the literature. Dis. Colon Rectum 2003; 46: 1141–3. 5. Singh B, Gupta S. Abdominal cocoon: a case series. Int. J. Surg. 2013; 11: 325–8. 6. Al-Thani H, El Mabrok J, Al Shaibani N, El-Menyar A. Abdominal cocoon and adhesiolysis: a case report and a literature review. Case Rep. Gastrointest. Med. 2013; 2013: 381950. 7. Foo K, Ng K, Rauff A, Foong W, Sinniah R. Unusual small intestinal obstruction in adolescent girls: the abdominal cocoon. Br. J. Surg. 1978; 65: 427–30. 8. Hur J, Kim K, Park M-S, Yu J-S. Abdominal cocoon: preoperative diagnostic clues from radiologic imaging with pathologic correlation. AJR Am. J. Roentgenol. 2004; 182: 639–41. 9. Donnelly L, Rencken I, deLorimer A, Gooding C. Left paraduodenal hernia leading to ileal obstruction. Pediatr. Radiol. 1996; 26: 534–6.
David Stewart,* MBBS Rajay Rampersad,* MBBS Sebastian K. King,*†‡ PhD, FRACS *Department of Paediatric and Neonatal Surgery, The Royal Children’s Hospital, Melbourne, Victoria, Australia, †Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia and ‡Department of Surgical Research, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia doi: 10.1111/ans.12907
© 2014 Royal Australasian College of Surgeons
Peritoneal encapsulation as a cause for recurrent abdominal pain in a 16-year-old male A 16-year-old male presented with centralized abdominal pain and non-bilious vomiting. He had suffered many similar episodes since the age of 4 years, resulting in several hospital admissions and a diagnosis of recurrent abdominal migraine. He had no prior operative history. Initial abdominal examination revealed central and left lower quadrant tenderness with minimal distension, though the abdominal distension worsened following admission. There was no evidence of bowel obstruction on plain radiography and all blood tests were unremarkable. A subsequent abdominal ultrasound revealed a normal superior mesenteric artery/vein relationship. Multiple, dilated bowel loops were noted centrally, and the bowel wall appeared thickened. An abdominal computerized tomography (CT) identified a high-grade small bowel obstruction, with two areas of abrupt transition in the central abdomen suggestive of an internal hernia (Fig. 1). Laparotomy revealed a peritoneal sac extending from the lateral edge of the proximal jejunal mesentery to the medial edge of the descending colon mesentery (Fig. 2). The sac extended cranially to the left paraduodenal recess, with a narrowed neck inferomedially, and contained loops of viable small bowel. Following delivery of the small bowel, the majority of the sac was excised, with the remaining
fragment secured to the retroperitoneum to obliterate any residual opening. The post-operative course was uneventful and the patient was discharged after 7 days. Histological examination of the peritoneal sac demonstrated a layer of fibrous tissue focally covered by prominent mesothelium, with granular pigments suggestive of hair. The possibility of a previous localized perforation was suggested. Peritoneal encapsulation is a rare cause of small bowel obstruction.1,2 Also referred to as abdominal cocoon or idiopathic encapsulating peritonitis, the condition features total or partial encapsulation of the small bowel within a fibro-collagenous membrane.1,3 The condition is often diagnosed incidentally.1 Peritoneal encapsulation may be either a primary or secondary phenomenon. Though the pathogenesis of primary peritoneal encapsulation remains poorly understood, it has been suggested that the peritoneal sheath is derived from the yolk sac lining following reduction of the midgut into the coelomic cavity.4 Secondary causes include retrograde menstruation, ventriculo-peritoneal shunts, peritoneal dialysis, abdominal tuberculosis, sarcoidosis, cirrhosis and systemic lupus erythematosus.5–7 Subclinical peritonitis is thought to be another secondary cause, and is suspected in the case presented above. In endemic areas, tuberculosis is a particularly common cause for peritoneal encapsulation, with Singh et al. reporting 50%
Fig. 1. Abdominal computerized tomography (CT) demonstrating the two transition points at the entry to the peritoneal sac (arrow), with contained small bowel loops.
Fig. 2. Intra-operative photograph of the peritoneal sac (arrow). The sac is demonstrated cranially, with contained small bowel loops. The free small bowel loops are situated caudally.
© 2014 Royal Australasian College of Surgeons
ANZ J Surg •• (2014) ••–••
2
of their patients as having proven peritoneal encapsulation of tubercular aetiology.5 The condition may affect both paediatric and adult populations. Patients typically present with features of small bowel obstruction, including abdominal pain, vomiting and abdominal distension.6 Pain is caused by compression or kinking of the intestine within the sac.5 As illustrated in the above case, patients may experience such symptoms intermittently for months or even years before definitive diagnosis. Suggestive physical examination findings include fixed asymmetrical abdominal distension and differences in consistency upon palpation of the abdominal wall.6 Preoperative diagnosis of this condition is difficult.6 Reports of the effectiveness of contrast studies, including the presence of a ‘cauliflower sign’, are variable.8 Ultrasound and CT have been suggested as the more specific imaging modalities.5 A mass of small bowel loops may be evident on CT, with intestinal dilatation and an obvious transition point.6 Symptoms and radiological findings may be very similar to paraduodenal or other types of internal herniae, making it challenging to differentiate between these diagnoses preoperatively.5,9 In the setting of obstruction, operative intervention is required. A laparotomy is more commonly performed, though successful laparoscopic excision has been described.3 The operative principles include excision of the membrane, lysis of adhesions, avoidance of bowel injury and resection of non-viable bowel segments.3 This last step is rarely necessary, though cases of ischaemic bowel within a peritoneal sac have been reported. Sahoo et al.2 described gangrenous ileum, caecum, appendix, ascending colon and part of transverse colon all contained within the sac, requiring resection and ileocolic anastomosis. The long-term outcomes for patients with peritoneal encapsulation are generally excellent.5 For patients presenting with small bowel obstruction, in the absence of more common aetiologies, peritoneal encapsulation should be kept on the surgeon’s list of differential diagnoses. Awareness of this rare condition may lead to appropriate investigations, thus avoiding a delayed diagnosis.
Images for surgeons
References 1. Mordehai J, Kleiner O, Kirshtein B, Barki Y, Mares A. Peritoneal encapsulation: a rare cause of bowel obstruction in children. J. Pediatr. Surg. 2001; 36: 1059–61. 2. Sahoo S, Gangopadhyay A, Gupta D, Gopal S, Sharma S, Dash R. Abdominal cocoon in children: a report of four cases. J. Pediatr. Surg. 1996; 7: 987–8. 3. Ertem M, Ozben V, Gok H, Aksu E. An unusual case in surgical emergency: abdominal cocoon and its laparoscopic management. J. Minim. Access Surg. 2011; 7: 184–6. 4. Rajagopal A, Rajagopal R. Conundrum of the cocoon. Report of a case and review of the literature. Dis. Colon Rectum 2003; 46: 1141–3. 5. Singh B, Gupta S. Abdominal cocoon: a case series. Int. J. Surg. 2013; 11: 325–8. 6. Al-Thani H, El Mabrok J, Al Shaibani N, El-Menyar A. Abdominal cocoon and adhesiolysis: a case report and a literature review. Case Rep. Gastrointest. Med. 2013; 2013: 381950. 7. Foo K, Ng K, Rauff A, Foong W, Sinniah R. Unusual small intestinal obstruction in adolescent girls: the abdominal cocoon. Br. J. Surg. 1978; 65: 427–30. 8. Hur J, Kim K, Park M-S, Yu J-S. Abdominal cocoon: preoperative diagnostic clues from radiologic imaging with pathologic correlation. AJR Am. J. Roentgenol. 2004; 182: 639–41. 9. Donnelly L, Rencken I, deLorimer A, Gooding C. Left paraduodenal hernia leading to ileal obstruction. Pediatr. Radiol. 1996; 26: 534–6.
David Stewart,* MBBS Rajay Rampersad,* MBBS Sebastian K. King,*†‡ PhD, FRACS *Department of Paediatric and Neonatal Surgery, The Royal Children’s Hospital, Melbourne, Victoria, Australia, †Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia and ‡Department of Surgical Research, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia doi: 10.1111/ans.12907
© 2014 Royal Australasian College of Surgeons
