- Email: [email protected]
Parasitic omphalopagus complicated by omphalocele and congenital heart disease
Parasitic Omphalopagus Complicated by Omphalocele and Congenital Heart Disease By Daniel A. De Ugarte, M. Ines Boechat, William W. Shaw, Hillel Laks, Holly Williams, and James B. Atkinson Los Angeles, California
Conjoined twins occur in approximately one of every 50,000 to 200,000 births. Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus refers to conjoined twins joined at the level of the umbilicus. The authors report a case of atypical omphalopagus involving an acardiac, acephalic, parasitic twin and a host twin with a large omphalocele, transposition of the great arteries, and aortic coarctation. The authors briefly review reported cases
of parasitic omphalopagus and emphasize the role of intensive neonatal care, preoperative planning, and staged surgical intervention in the successful management of complicated variants. J Pediatr Surg 37:1357-1358. Copyright 2002, Elsevier Science (USA). All rights reserved.
C
twin A’s stomach. The posterior wall was ischemic with thrombosed vessels. However, the gastric artery was patent. A subtotal gastrectomy, gastric and esophageal closure, and gastrostomy were performed. On DOL 13, the newborn was taken to the operating room with the goal of reconstructing the gastrointestinal tract and completing the separation of the parasitic twin. However, examination of twin A’s bowel found an obstructive pattern and inspissated meconium 25 cm proximal to the ileocecal valve. The distal terminal ileum and colon appeared collapsed. Multiple biopsy specimens of the bowel wall were taken, and frozen sections were suggestive of Hirschsprung’s disease. A segment of small bowel with Meckel’s diverticulum was removed, and an end ileostomy was performed. Separation of the parasitic twin was then completed. Two fused livers and 2 normal gallbladders were identified in the abdomen of twin A. Because the biliary system appeared to be patent with both systems draining into the gastrointestinal tract of twin A, these structures were left intact. The excised specimen included loops of bowel, hydronephrotic kidney, bladder, pelvis and lower extremities, imperforate anus, and undescended testis of twin B. An esophagogastric anastamosis was performed to restore continuity of the gastrointestinal tract. Residual fundus was removed to prevent acid reflux. Esophagojejunostomy was not performed given the possible diagnosis of Hirschsprung’s disease and distal obstruction. Closure of the abdominal wall and a cleft inferior sternum was achieved using the gluteal skin of the parasitic twin as a rotational flap. Postoperatively, the patient experienced significant amounts of reflux, required replogle suctioning, and was dependent on total parenteral nutrition (TPN). Final pathology of the intestinal wall biopsies showed ganglion cells in the sigmoid and small bowel. The bowel obstruction was attributed to meconium ileus, and the patient underwent washout of the distal alimentary tract under fluoroscopic guid-
ONJOINED TWINS occur in approximately one of every 50,000 to 200,000 births.1 Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus is a variant of conjoined twins that involves union at the level of the umbilicus. We report a case of parasitic omphalopagus complicated by a large omphalocele, transposition of the great arteries (TGA), and aortic coarctation. CASE REPORT
A 3,000-g male conjoined twin known antenatally to have a large omphalocele and complex congenital heart disease was delivered by elective cesarean section to a 29-year-old G2, P1 mother at 38 weeks’ gestation. The newborn was intubated and started on prostaglandins. Examination of the conjoined twin (Fig 1) found an acardic acephalic parasitic twin (twin B) with dysmorphic arms, normal legs, pelvis, buttocks, genitalia, and a palpable spine emanating from the epigastric region of the primary twin (twin A). The patient was taken to the operating room for primary closure of a leaking omphalocele and placement of monitoring lines. Because of the patient’s poor cardiac function secondary to inadequate pulmonary blood flow and the high operative risk, we did not plan on undertaking separation of twin B at the time of the initial surgery. However, the location of the dysmorphic arms overlying the chest in an area that would impede imaging of the heart compelled us to amputate these limbs. Postnatal echocardiography confirmed d-transposition of the great arteries, aortic coarctation, PDA, PFO, and 2 VSDs. On day of life 4 (DOL 4), the patient underwent cardiac catheterization and Rashkind balloon atrial septostomy. The septostomy allowed shunting between the systemic and pulmonary circulatory systems resulting in an improvement in oxygen saturation. Three-dimensional magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) confirmed the findings noted on cardiac catheterization and found a blood supply to twin B originating from a branch of the right innominate artery of twin A. On DOL 8, abdominal distension developed, and free air was noted on KUB. Exploratory laparatomy found a 2-cm anterior perforation of
INDEX WORDS: Conjoined twin, atypical, heteropagus, omphalopagus, omphalocele.
From UCLA Department of Pediatric Surgery, Cardiothoracic Surgery, Plastic and Reconstructive Surgery, and Pediatric Radiology, Los Angeles, CA. Address reprint requests to James B. Atkinson, UCLA Department of Pediatric Surgery, 10833 LeConte Ave, Los Angeles, CA 90095. Copyright 2002, Elsevier Science (USA). All rights reserved. 0022-3468/02/3709-0023$35.00/0 doi:10.1053/jpsu.2002.35011
Journal of Pediatric Surgery, Vol 37, No 9 (September), 2002: pp 1357-1358
1357
1358
DE UGARTE ET AL
Fig 1. Appearance of the infant shortly after birth and before surgical intervention.
ance. The patient could not be weaned off of the ventilator and was maintained on 100% FIO2 to achieve oxygen saturations of only 60% to 70%. On DOL 26, the infant underwent a left thoracotomy for repair of the aortic coarctation, pulmonary artery banding, ligation of the PDA, and plication of a left flail diaphragm. On DOL 75, the newborn had been successfully weaned off of pressors, treated with antibiotics for pneumonia, and was taken for arterial switch procedure and repair of ASDs and VSDs. The patient’s hemodynamic status improved dramatically, and the patient was extubated on DOL 85. Furthermore, there was a marked improvement in the tolerance of tube feedings, and the TPN was weaned off. Results of gastrograffin swallow showed no evidence of esophageal reflux. On day 117, the patient was discharged home on diuretics, digoxin, and aspirin. Albuterol and cromolyn inhalers and supplemental nasal canula oxygen also were provided for the patient’s bronchopulmonary dysplasia. The patient was tolerating goal rate nasojejunal tube feedings. No esophageal reflux was noted on gastrograffin swallow. It is anticipated that the child will be weaned off cardiac medications, oxygen, and tube feedings over the next couple of years. An ileostomy takedown is planned for the near future.
DISCUSSION
Conjoined twins are believed to result from the fusion of embryonic discs originating from a single zygote and not the fusion of dizygotic twins.2 All reported cases of conjoined twins are of the same sex, strongly supporting
this theory. In this case, a single normal chromosomal pattern 46,XY identified on amniocentesis and a monoamniotic, monochorionic placenta with a single 3-vessel cord support a monozygotic origin. There was no maternal or family history of alcohol or drug use, diabetes mellitus, congenital heart disease, or consanguinity to account for the identified congenital anomalies. Fusion of the embryonic discs at the level of the umbilicus results in a variant called omphalopagus. Parasitic twins (formerly referred to as asymmetrical or heteropagus twins3) result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Embryonic death of the parasitic twin is likely caused by ischemic atrophy and may be the result of insufficient cardiac function of the parasitic twin or vascular steal from the primary twin. A review of reported cases of parasitic omphalopagus shows a strong male predominance and a high frequency of other congenital abnormalities.4,5 Eight of 11 reported cases have been boys. This is in marked contrast to the 3:1 female to male ratio seen in conjoined twins as whole.6 Omphaloceles were found in 7 of 11 reported cases. Conjoined livers also appear to be common. However, there have been no reports of direct communication between the bowels of twins. Vascular connections have been reported to arise from the liver, internal mammary artery, epigastric vessels, and the falciform ligament. Congenital heart disease has been described in about half of the reported cases of parasitic omphalopagus.4,5,7-9 The 2 reported cases of complicated congenital heart disease resulted in death.4,7 Careful staging of the required operative interventions as illustrated in the management of this case are more likely to yield a successful outcome for the primary twin. Even in the setting of extensive operative planning, emergent and unexpected findings (eg, gastric perforation and small bowel obstruction in this case) cannot always be anticipated or prevented.
REFERENCES 1. Edmonds LD, Layde PM: Conjoined twins in the United States, 1970-1977. Teratology 25:301-308, 1982 2. Spencer R: Conjoined twins: Theoretical embryologic basis. Teratology 45:591-602, 1992 3. Spencer R: Anatomic description of conjoined twins: A plea for standardized terminology. J Pediatr Surg 31:941-944, 1996 4. Hwang EH, Han SJ, Lee SJ, et al: An unusual case of monozygotic epigastric heteropagus twinning. J Pediatr Surg 31:1457-1460, 1996 5. Jain PK, Budhwani KS, Gambhir A, et al: Omphalopagus parasite: A rare congenital anomaly. J Pediatr Surg 33:946-947, 1998
6. O’Neill JA Jr, Holcomb GW III, Schnaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 208:299-312, 1988 7. Poradowska W, Jaworska M, Reszke S, et al: Conjoined twins and twin parasites: A clinical analysis of three examples. J Pediatr Surg 4:688-693, 1969 8. Cywes S, Davies MRQ, Rode H: Conjoined twins—The Red Cross War Memorial Children’s Hospital experience. South Afr J Surg 20:105-118, 1982 9. Nasta R, Scibilia G, Corrao A, et al: Surgical treatment of an asymmetric double monstrosity with esophageal atresia, omphalocele, and interventricular defect. J Pediatr Surg 21:60-62, 1986
Conjoined twins occur in approximately one of every 50,000 to 200,000 births. Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus refers to conjoined twins joined at the level of the umbilicus. The authors report a case of atypical omphalopagus involving an acardiac, acephalic, parasitic twin and a host twin with a large omphalocele, transposition of the great arteries, and aortic coarctation. The authors briefly review reported cases
of parasitic omphalopagus and emphasize the role of intensive neonatal care, preoperative planning, and staged surgical intervention in the successful management of complicated variants. J Pediatr Surg 37:1357-1358. Copyright 2002, Elsevier Science (USA). All rights reserved.
C
twin A’s stomach. The posterior wall was ischemic with thrombosed vessels. However, the gastric artery was patent. A subtotal gastrectomy, gastric and esophageal closure, and gastrostomy were performed. On DOL 13, the newborn was taken to the operating room with the goal of reconstructing the gastrointestinal tract and completing the separation of the parasitic twin. However, examination of twin A’s bowel found an obstructive pattern and inspissated meconium 25 cm proximal to the ileocecal valve. The distal terminal ileum and colon appeared collapsed. Multiple biopsy specimens of the bowel wall were taken, and frozen sections were suggestive of Hirschsprung’s disease. A segment of small bowel with Meckel’s diverticulum was removed, and an end ileostomy was performed. Separation of the parasitic twin was then completed. Two fused livers and 2 normal gallbladders were identified in the abdomen of twin A. Because the biliary system appeared to be patent with both systems draining into the gastrointestinal tract of twin A, these structures were left intact. The excised specimen included loops of bowel, hydronephrotic kidney, bladder, pelvis and lower extremities, imperforate anus, and undescended testis of twin B. An esophagogastric anastamosis was performed to restore continuity of the gastrointestinal tract. Residual fundus was removed to prevent acid reflux. Esophagojejunostomy was not performed given the possible diagnosis of Hirschsprung’s disease and distal obstruction. Closure of the abdominal wall and a cleft inferior sternum was achieved using the gluteal skin of the parasitic twin as a rotational flap. Postoperatively, the patient experienced significant amounts of reflux, required replogle suctioning, and was dependent on total parenteral nutrition (TPN). Final pathology of the intestinal wall biopsies showed ganglion cells in the sigmoid and small bowel. The bowel obstruction was attributed to meconium ileus, and the patient underwent washout of the distal alimentary tract under fluoroscopic guid-
ONJOINED TWINS occur in approximately one of every 50,000 to 200,000 births.1 Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus is a variant of conjoined twins that involves union at the level of the umbilicus. We report a case of parasitic omphalopagus complicated by a large omphalocele, transposition of the great arteries (TGA), and aortic coarctation. CASE REPORT
A 3,000-g male conjoined twin known antenatally to have a large omphalocele and complex congenital heart disease was delivered by elective cesarean section to a 29-year-old G2, P1 mother at 38 weeks’ gestation. The newborn was intubated and started on prostaglandins. Examination of the conjoined twin (Fig 1) found an acardic acephalic parasitic twin (twin B) with dysmorphic arms, normal legs, pelvis, buttocks, genitalia, and a palpable spine emanating from the epigastric region of the primary twin (twin A). The patient was taken to the operating room for primary closure of a leaking omphalocele and placement of monitoring lines. Because of the patient’s poor cardiac function secondary to inadequate pulmonary blood flow and the high operative risk, we did not plan on undertaking separation of twin B at the time of the initial surgery. However, the location of the dysmorphic arms overlying the chest in an area that would impede imaging of the heart compelled us to amputate these limbs. Postnatal echocardiography confirmed d-transposition of the great arteries, aortic coarctation, PDA, PFO, and 2 VSDs. On day of life 4 (DOL 4), the patient underwent cardiac catheterization and Rashkind balloon atrial septostomy. The septostomy allowed shunting between the systemic and pulmonary circulatory systems resulting in an improvement in oxygen saturation. Three-dimensional magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) confirmed the findings noted on cardiac catheterization and found a blood supply to twin B originating from a branch of the right innominate artery of twin A. On DOL 8, abdominal distension developed, and free air was noted on KUB. Exploratory laparatomy found a 2-cm anterior perforation of
INDEX WORDS: Conjoined twin, atypical, heteropagus, omphalopagus, omphalocele.
From UCLA Department of Pediatric Surgery, Cardiothoracic Surgery, Plastic and Reconstructive Surgery, and Pediatric Radiology, Los Angeles, CA. Address reprint requests to James B. Atkinson, UCLA Department of Pediatric Surgery, 10833 LeConte Ave, Los Angeles, CA 90095. Copyright 2002, Elsevier Science (USA). All rights reserved. 0022-3468/02/3709-0023$35.00/0 doi:10.1053/jpsu.2002.35011
Journal of Pediatric Surgery, Vol 37, No 9 (September), 2002: pp 1357-1358
1357
1358
DE UGARTE ET AL
Fig 1. Appearance of the infant shortly after birth and before surgical intervention.
ance. The patient could not be weaned off of the ventilator and was maintained on 100% FIO2 to achieve oxygen saturations of only 60% to 70%. On DOL 26, the infant underwent a left thoracotomy for repair of the aortic coarctation, pulmonary artery banding, ligation of the PDA, and plication of a left flail diaphragm. On DOL 75, the newborn had been successfully weaned off of pressors, treated with antibiotics for pneumonia, and was taken for arterial switch procedure and repair of ASDs and VSDs. The patient’s hemodynamic status improved dramatically, and the patient was extubated on DOL 85. Furthermore, there was a marked improvement in the tolerance of tube feedings, and the TPN was weaned off. Results of gastrograffin swallow showed no evidence of esophageal reflux. On day 117, the patient was discharged home on diuretics, digoxin, and aspirin. Albuterol and cromolyn inhalers and supplemental nasal canula oxygen also were provided for the patient’s bronchopulmonary dysplasia. The patient was tolerating goal rate nasojejunal tube feedings. No esophageal reflux was noted on gastrograffin swallow. It is anticipated that the child will be weaned off cardiac medications, oxygen, and tube feedings over the next couple of years. An ileostomy takedown is planned for the near future.
DISCUSSION
Conjoined twins are believed to result from the fusion of embryonic discs originating from a single zygote and not the fusion of dizygotic twins.2 All reported cases of conjoined twins are of the same sex, strongly supporting
this theory. In this case, a single normal chromosomal pattern 46,XY identified on amniocentesis and a monoamniotic, monochorionic placenta with a single 3-vessel cord support a monozygotic origin. There was no maternal or family history of alcohol or drug use, diabetes mellitus, congenital heart disease, or consanguinity to account for the identified congenital anomalies. Fusion of the embryonic discs at the level of the umbilicus results in a variant called omphalopagus. Parasitic twins (formerly referred to as asymmetrical or heteropagus twins3) result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Embryonic death of the parasitic twin is likely caused by ischemic atrophy and may be the result of insufficient cardiac function of the parasitic twin or vascular steal from the primary twin. A review of reported cases of parasitic omphalopagus shows a strong male predominance and a high frequency of other congenital abnormalities.4,5 Eight of 11 reported cases have been boys. This is in marked contrast to the 3:1 female to male ratio seen in conjoined twins as whole.6 Omphaloceles were found in 7 of 11 reported cases. Conjoined livers also appear to be common. However, there have been no reports of direct communication between the bowels of twins. Vascular connections have been reported to arise from the liver, internal mammary artery, epigastric vessels, and the falciform ligament. Congenital heart disease has been described in about half of the reported cases of parasitic omphalopagus.4,5,7-9 The 2 reported cases of complicated congenital heart disease resulted in death.4,7 Careful staging of the required operative interventions as illustrated in the management of this case are more likely to yield a successful outcome for the primary twin. Even in the setting of extensive operative planning, emergent and unexpected findings (eg, gastric perforation and small bowel obstruction in this case) cannot always be anticipated or prevented.
REFERENCES 1. Edmonds LD, Layde PM: Conjoined twins in the United States, 1970-1977. Teratology 25:301-308, 1982 2. Spencer R: Conjoined twins: Theoretical embryologic basis. Teratology 45:591-602, 1992 3. Spencer R: Anatomic description of conjoined twins: A plea for standardized terminology. J Pediatr Surg 31:941-944, 1996 4. Hwang EH, Han SJ, Lee SJ, et al: An unusual case of monozygotic epigastric heteropagus twinning. J Pediatr Surg 31:1457-1460, 1996 5. Jain PK, Budhwani KS, Gambhir A, et al: Omphalopagus parasite: A rare congenital anomaly. J Pediatr Surg 33:946-947, 1998
6. O’Neill JA Jr, Holcomb GW III, Schnaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 208:299-312, 1988 7. Poradowska W, Jaworska M, Reszke S, et al: Conjoined twins and twin parasites: A clinical analysis of three examples. J Pediatr Surg 4:688-693, 1969 8. Cywes S, Davies MRQ, Rode H: Conjoined twins—The Red Cross War Memorial Children’s Hospital experience. South Afr J Surg 20:105-118, 1982 9. Nasta R, Scibilia G, Corrao A, et al: Surgical treatment of an asymmetric double monstrosity with esophageal atresia, omphalocele, and interventricular defect. J Pediatr Surg 21:60-62, 1986