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Discordant intestinal malrotation in identical twins A 33-year-old woman was admitted to our unit with acute cramplike abdominal pain. Her symptoms began during the night and were associated with vomiting, non-specific abdominal tenderness, significant abdominal distension and loss of flatus. Her past medical history included chronic abdominal pain since childhood but no previous illness or surgery. The patient claimed that she had an identical monozygotic twin. Routine admission blood tests demonstrated an elevated white blood cell count and normal C-reactive protein. A diagnosis of acute intestinal obstruction was suspected. After intravenous fluid resuscitation, a contrast-enhanced computed tomography (CT) scan was performed, which revealed distension of the small intestine and ascending colon, in which a twist was identified as a sign of stricture. Thus, a volvulus was suspected, and the patient was taken to the operating room to undergo an emergency exploratory coelioscopy. The exploration showed rotation around the first third of the transverse colon of the small intestine and ascending colon (Fig. 1a) and detected an abnormal position of the duodenum, which failed to cross the midline behind the mesentery, with complete exposure of the pancreatic head (Fig. 1b). Conversion by midline laparotomy was then performed, confirming the diagnosis of a volvulus of the complete common mesentery due to fixation of the greater omentum along the left mesocolon. Then, the epiploic adhesions were divided, and after derotation and an appendicectomy, the small intestine was placed on the right side of the abdomen, whereas the caecum was returned to the left iliac fossa in a complete common mesentery position (Fig. 2). The post-operative period was uneventful, and the patient was discharged to her home on day 6 post-surgery. Her twin sister was screened for intestinal malrotation (IM) by CT, which was unexpectedly normal.
IM is a congenital anomaly of midgut rotation during the fetal development. During the fifth intrauterine week, rapid elongation of the intestine results in herniation of the midgut through the umbilical cord. Simultaneously, the intestine rotates in an anticlockwise direction around the axis of the superior mesenteric artery, for a total of 270°. The process is completed during the 10th week, when the intestine returns to the abdominal cavity.1 The failures of rotation include rare cases of ‘non-rotation,’ cases of interrupted rotation in a 90° anticlockwise position (complete common mesentery position, in which the small bowel is on the right side of the abdomen and the caecum is on the left iliac fossa) or, most often, in a 180° anticlockwise position (incomplete common mesentery position, in which the caecum is close to the liver). The incomplete mesentery position is the position for which the risk of an intestinal volvulus is greatest due to the narrowness of the mesentery root. Thus, most cases of IM are diagnosed in the first month of life, and the incidence of IM in asymptomatic adults is reported to be extremely low.2 Surgical correction of an IM by Ladd’s procedure is preferred when an incomplete common mesentery is symptomatic, placing the bowels in a complete mesentery position after derotation and an appendicectomy. Our patient suffered from a volvulus of the midgut, whereas the mesentery was already in a complete common position. This condition is rarer than a volvulus of the incomplete mesentery due to widening of the mesentery root. IM is believed to result from the deficiency of several genes that are necessary for fetal development.1 Familial cases of IM have been published;3–5 further, four cases of simultaneous occurrence of IM in identical twins have also been reported,6–9 suggesting an autosomal dominant or recessive inheritance pattern and a strong correlation of IM in monozygotic twins. In our case, the patient’s twin sister also benefitted from a CT, which did not reveal any signs of IM, although
Fig. 1. Preoperative coelioscopic view. (a) Volvulus of the small intestine which is twisted around the transverse colon. (b) The non-rotation of the midgut results in the complete exposure of the pancreatic head (asterisk) due to the absence of fixation of the transverse mesocolon root.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Fig. 2. The complete common mesentery position: the small intestine (a) is on the right side of the abdomen, whereas the colon (b = ascending colon; c = transverse colon; d = descending colon; e = sigmoid) is on the left side.
the twins were monozygotic. To date, this case is the second case of discordant IM in identical twins,10 implicating epigenetic phenomena, in addition to the genetic inheritance pattern, in the development of IM.
Images for surgeons
2. Emanuwa OF, Ayantunde AA, Davies TW. Midgut malrotation first presenting as acute bowel obstruction in adulthood: a case report and literature review. World J. Emerg. Surg. 2011; 6: 22. 3. Stalker HJ, Chitayat D. Familial intestinal malrotation with midgut volvulus and facial anomalies: a disorder involving a gene controlling the normal gut rotation? Am. J. Med. Genet. 1992; 44: 46–7. 4. Carmi R, Abeliovich D, Siplovich L, Zmora E, Bar-Ziv J. Familial midgut anomalies – a spectrum of defects due to the same cause? Am. J. Med. Genet. 1981; 8: 443–6. 5. Smith SL. Familial midgut volvulus. Surgery 1972; 72: 420–6. 6. Kikuchi S, Akuzawa K, Otaki T et al. A simultaneous occurrence of malrotation in twin newborns. Fukushima J. Med. Sci. 1977; 24: 63–6. 7. Crowley JJ, Bawle E. Small bowel malrotation in each of a pair of identical twins. Pediatr. Radiol. 1966; 26: 127–8. 8. Burton EM, Strange ME, Pitts RM. Malrotation in twins: a rare occurrence. Pediatr. Radiol. 1993; 23: 603–4. 9. Olson LM, Flom LS, Kierney CM, Shermeta DW. Identical twins with malrotation and type IV jejunal atresia. J. Pediatr. Surg. 1987; 22: 1015–6. 10. Smith VL, Long F, Nwomeh BC. Monozygotic twins with discordant intestinal rotation. Pediatr. Radiol. 2006; 36: 352–4.
Stéphane Bourgouin, MD Ghislain Schlienger, MD François-Xavier Deledalle, MD Hervé Thouard, MD Department of Visceral and Vascular Surgery, Sainte-Anne Military Teaching Hospital, Toulon, France doi: 10.1111/ans.13013
References 1. Martin V, Shaw-Smith C. Review of genetic factors in intestinal malrotation. Pediatr. Surg. Int. 2010; 26: 769–81.
© 2015 Royal Australasian College of Surgeons
Discordant intestinal malrotation in identical twins A 33-year-old woman was admitted to our unit with acute cramplike abdominal pain. Her symptoms began during the night and were associated with vomiting, non-specific abdominal tenderness, significant abdominal distension and loss of flatus. Her past medical history included chronic abdominal pain since childhood but no previous illness or surgery. The patient claimed that she had an identical monozygotic twin. Routine admission blood tests demonstrated an elevated white blood cell count and normal C-reactive protein. A diagnosis of acute intestinal obstruction was suspected. After intravenous fluid resuscitation, a contrast-enhanced computed tomography (CT) scan was performed, which revealed distension of the small intestine and ascending colon, in which a twist was identified as a sign of stricture. Thus, a volvulus was suspected, and the patient was taken to the operating room to undergo an emergency exploratory coelioscopy. The exploration showed rotation around the first third of the transverse colon of the small intestine and ascending colon (Fig. 1a) and detected an abnormal position of the duodenum, which failed to cross the midline behind the mesentery, with complete exposure of the pancreatic head (Fig. 1b). Conversion by midline laparotomy was then performed, confirming the diagnosis of a volvulus of the complete common mesentery due to fixation of the greater omentum along the left mesocolon. Then, the epiploic adhesions were divided, and after derotation and an appendicectomy, the small intestine was placed on the right side of the abdomen, whereas the caecum was returned to the left iliac fossa in a complete common mesentery position (Fig. 2). The post-operative period was uneventful, and the patient was discharged to her home on day 6 post-surgery. Her twin sister was screened for intestinal malrotation (IM) by CT, which was unexpectedly normal.
IM is a congenital anomaly of midgut rotation during the fetal development. During the fifth intrauterine week, rapid elongation of the intestine results in herniation of the midgut through the umbilical cord. Simultaneously, the intestine rotates in an anticlockwise direction around the axis of the superior mesenteric artery, for a total of 270°. The process is completed during the 10th week, when the intestine returns to the abdominal cavity.1 The failures of rotation include rare cases of ‘non-rotation,’ cases of interrupted rotation in a 90° anticlockwise position (complete common mesentery position, in which the small bowel is on the right side of the abdomen and the caecum is on the left iliac fossa) or, most often, in a 180° anticlockwise position (incomplete common mesentery position, in which the caecum is close to the liver). The incomplete mesentery position is the position for which the risk of an intestinal volvulus is greatest due to the narrowness of the mesentery root. Thus, most cases of IM are diagnosed in the first month of life, and the incidence of IM in asymptomatic adults is reported to be extremely low.2 Surgical correction of an IM by Ladd’s procedure is preferred when an incomplete common mesentery is symptomatic, placing the bowels in a complete mesentery position after derotation and an appendicectomy. Our patient suffered from a volvulus of the midgut, whereas the mesentery was already in a complete common position. This condition is rarer than a volvulus of the incomplete mesentery due to widening of the mesentery root. IM is believed to result from the deficiency of several genes that are necessary for fetal development.1 Familial cases of IM have been published;3–5 further, four cases of simultaneous occurrence of IM in identical twins have also been reported,6–9 suggesting an autosomal dominant or recessive inheritance pattern and a strong correlation of IM in monozygotic twins. In our case, the patient’s twin sister also benefitted from a CT, which did not reveal any signs of IM, although
Fig. 1. Preoperative coelioscopic view. (a) Volvulus of the small intestine which is twisted around the transverse colon. (b) The non-rotation of the midgut results in the complete exposure of the pancreatic head (asterisk) due to the absence of fixation of the transverse mesocolon root.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Fig. 2. The complete common mesentery position: the small intestine (a) is on the right side of the abdomen, whereas the colon (b = ascending colon; c = transverse colon; d = descending colon; e = sigmoid) is on the left side.
the twins were monozygotic. To date, this case is the second case of discordant IM in identical twins,10 implicating epigenetic phenomena, in addition to the genetic inheritance pattern, in the development of IM.
Images for surgeons
2. Emanuwa OF, Ayantunde AA, Davies TW. Midgut malrotation first presenting as acute bowel obstruction in adulthood: a case report and literature review. World J. Emerg. Surg. 2011; 6: 22. 3. Stalker HJ, Chitayat D. Familial intestinal malrotation with midgut volvulus and facial anomalies: a disorder involving a gene controlling the normal gut rotation? Am. J. Med. Genet. 1992; 44: 46–7. 4. Carmi R, Abeliovich D, Siplovich L, Zmora E, Bar-Ziv J. Familial midgut anomalies – a spectrum of defects due to the same cause? Am. J. Med. Genet. 1981; 8: 443–6. 5. Smith SL. Familial midgut volvulus. Surgery 1972; 72: 420–6. 6. Kikuchi S, Akuzawa K, Otaki T et al. A simultaneous occurrence of malrotation in twin newborns. Fukushima J. Med. Sci. 1977; 24: 63–6. 7. Crowley JJ, Bawle E. Small bowel malrotation in each of a pair of identical twins. Pediatr. Radiol. 1966; 26: 127–8. 8. Burton EM, Strange ME, Pitts RM. Malrotation in twins: a rare occurrence. Pediatr. Radiol. 1993; 23: 603–4. 9. Olson LM, Flom LS, Kierney CM, Shermeta DW. Identical twins with malrotation and type IV jejunal atresia. J. Pediatr. Surg. 1987; 22: 1015–6. 10. Smith VL, Long F, Nwomeh BC. Monozygotic twins with discordant intestinal rotation. Pediatr. Radiol. 2006; 36: 352–4.
Stéphane Bourgouin, MD Ghislain Schlienger, MD François-Xavier Deledalle, MD Hervé Thouard, MD Department of Visceral and Vascular Surgery, Sainte-Anne Military Teaching Hospital, Toulon, France doi: 10.1111/ans.13013
References 1. Martin V, Shaw-Smith C. Review of genetic factors in intestinal malrotation. Pediatr. Surg. Int. 2010; 26: 769–81.
© 2015 Royal Australasian College of Surgeons
