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Preduodenal portal vein
Preduodenal Portal Vein By Richard J. Bower and Jessie L. Ternberg
W
E HAVE ENCOUNTERED three examples of preduodenal portal vein during the past year. Twenty-nine cases of this anomaly were documented in reviewing the literature. Analysis of these cases emphasizes that the anomaly has a high association with other congenital anomalies, and that a preduodenal portal vein in some instances may be a cause of duodenal obstruction. Potential technical hazards. make it important that this entity be recognized. CASE HISTORIES
Case 1, E.W. A 3-yr-old black girl was transferred to St. Louis Children’s Hospital with a history of intermittent vomiting. The patient had a long history of poor growth and frequent respiratory tract infections. A diagnosis of malrotation was made on the upper gastrointestinal roentgen examination. At operation, reverse rotation was found. The left lobe of the liver was larger than the right and the gallbladder was to the left of the falciform ligament, In addition, the portal vein was anterior to the first portion of the duodenum, which was found to be entirely intraperitoneal. The portal vein was causing partial obstruction. An end-to-end duodenoduodenostomy was performed. This placed the portal vein dorsal to the duodenum. The child has done weI1. In addition to the abdominal anomalies, the child has a right aortic arch with an aberrant left subclavian artery forming a loose vascular ring.
Case 2, R.S. A &day-old white female infant was transferred to St. Louis Children’s Hospital with a one-day history of bilious vomiting. Abdominal roentgenological showed a large amount of air in the stomach but little air in the remainder of the gastrointestinal tract. A barium enema showed a colon of normal calibre with the cecum in the right lower quadrant. However, most of the colon was in the right abdomen. The upper gastrointestinal radiologic examination showed high-grade duodenal obstruction with an anteriorly placed duodenum. This picture suggested “reverse rotation.” At operation the duodenum was intraperitoneal as in case 1. The portal vein passed anterior (ventral) to the first portion of the duodenum, but was not causing any obstruction. A duodenal web in the third portion of the duodenum was found. The web was excised. The patient was reoperated upon at age 2 wk for intestinal obstruction secondary to adhesions. She was discharged 7 days later and on subsequent follow-up has done well.
Case 3, A.P. A s-day-old premature Louis Children’s Hospital
black female infant weighing 2100 g was transferred to St. because of jaundice, abdominal distension, and vomiting, A
From the Department of Surgery, Washington Uninersity School of Medicine, and St. Hospital, Sf. Louis, MO. Presented at the Third Annual Meeting of the American Pediatric Surgical Association, Hot Springs, Vu., April 13-15, 2972. Richard J. Bower, M.D.: St. Louis Children’s Hospital, St. Louis, MO. Jessie L. Ternberg, M.D.: Departmenf of Surgery, Washington University School of Medicine, St. Louis, MO. Louis Children’s
&wnal Of F’edietriCsurgery. Vol. 7, No. 5 (October-November), 1972
579
580
BOWER AND TERNBERG
grade IV/VI systolic murmur was heard over the entire left chest. The Iiver was enlarged. A chest film showed pulmonary overcirculation, and an upper gastrointestinal radiological examination showed duodenal obstruction with evidence of malrotation. At operation the liver was enlarged and congested. The small bowel was collapsed. Ladd’s bands in the right upper quadrant were lysed. However, the duodenal obstruction was caused by the portal vein, which passed in front of the first portion of the duodenum and then behind the distal duodenum. The pancreas was present as a globular structure on the right side of the duodenum. We divided the proximal duodenum and performed end-to-end duodenoduodenostomy, placing the portal vein dorsal to the duodenum. Cardiac catheterization showed a double-outlet right ventricle. The child is now 6 mo old and doing poorly with heart failure.
DISCUSSION The first report of a preduodenal portal vein was made by Knight’ in 1921. He found this anomaly in a dissecting-room cadaver. However, the theory to account for such an occurrence was first put forth by His in 1885,2 and an
A
B
5 Weeks
6 Weeks
5 Weeks
6 Weeks
10 Weeks
10 Weeks
Fig. 1. (A) Normal development of portal vein. (6) Possible explanation of preduodenal portal vein.
PREDUODENALPORTALVEIN
581
example of this anomaly in a pig embryo was reported in 1912.3 Marks has recently reviewed the development of the portal venous system.4 Two vitelline veins and their three anastomotic connections eventually form the portal vein. There are thus at an early stage two rings of vascular tissue around the gastrointestinal tract, as described by His and since referred to as the “periintestinal ring theory.“ A portion of each ring degenerates and leaves the portal vein. This development occurs during the fifth to tenth weeks. The development is schematically shown in Fig. 1A. During the fifth week there are three connections between the veins. The developing duodenum passes anterior (ventral) to the second bridging anastomosis and posterior (dorsal) to the third. The first bridge lies within the liver. During the sixth week the proximal portion of the left vitelline vein and the distal portion of the right vitelline vein begin to regress. The second vascular bridge enlarges and persists as the portal vein and passed behind or dorsal to the duodenum. At 10 wk a single vein has been formed from the vitelline veins. To explain the occurrence of a preduodenal or ventral portal vein several events must occur, as illustrated in Fig. IB. The second anastomotic bridge begins to obliterate at the sixth week and the third bridge begins to enlarge. The portal vein is thus composed of the right vitelline vein and the third bridge (instead of the second), which passes anterior or ventral to the duodenum. The continuation of the portal vein and its bifurcation into splenic and superior mesenteric veins may be dorsal or ventral to the fourth duodenum. The 29 cases from the literature plus our three patients are summarized in Table 1. Twenty-two of the cases had the preduodenal portal vein discovered at operation; the other ten cases were anatomic descriptions of necropsy findings. Nineteen cases presented with acute or chronic intestinal obstruction originating above the ligament of Treitz. Four were adults who had long histories of epigastric complaints secondary to chronic gastric outlet obstruction. The etiology of the obstruction was the preduodenal portal vein in ten cases (Fig. 2). Other causes of the obstruction included duodenal atresia, doudenal stenosis, duodenal web, annular pancreas, malrotation, or a combination of these
Portal Vein 0
Fig. 2. Reported cases of preduodenal portal vein with intestinal struction.
ob-
@
v had $&%.ol Portal Vein as caure of obstruction
Portal Vein
BOWER AND TERNBERG
I Table 1. Cases Presenting With Intestinal Obstruction The complete bibliography may be obtained from Jessie L. Ternberg, M.D., Washington University School of Medicine, Department of Surgery, 4960 Audubon Ave., St. Louis, MO. 63110.
583
PREDUODENAL PORTAL VEIN Table 2. Anomalies
Reported in Patients with Preduodenal Portal Vein
Malrotations (incomplete, reverse, nonrotation, fixational Situs lnversus (partial or complete) Pancreatic anomalies (annular, ventral, no tail) Duodenal anomalies (atresia, stenosis, web) Biliary system anomalies (atresia, ectopic CBD) Sp!enic anomalies (multiple, bilobed, asp!enia) Dextrocardia Dextroposition of aorta VSD Persistent (L) SVC Vascular ring Double outlet (R) ventricle A-V communis Hypoplastic arch Sacral agenesis
errors)
23 9 8 8 8 6 5 3 2 2 1 1 1 1 1
anomalies. Of the ten cases in which the preduodenal portal vein was considered to have caused the obstruction, four had an associated anomaly that could also be a possible cause of obstruction. It is important, therefore, after recogrizing and treating the more common causes of duodenal obstruction, to be sure that the preduodenal portal vein is not also contributing to the obstruction. Our third patient is an example of this. Additional anomalies were present in many of the 32 cases (Table 2). The most commonly occurring anomaly was “malrotation” (23 cases). In the group of “malrotations” we have included the wide spectra of rotational and fixational errors that have been well described by Dott.5 Partial or complete situs inversus was another frequent finding (nine cases). Pancreatic and duodenal anomalies were also frequent. Only one of these patients was reported to have trisomy 21. There were 16 cardiovascular lesions in 11 patients, but only dextrocardia and dextroposition of the aorta occurred three times or more. Surgical therapy consists primarily of the treatment of associated anomalies. If the preduodenal portal vein causes the obstruction, the surgical procedure can be either an end-to-end duodenoduodenostomy (placing the portal vein in its normal dorsal position), or a bypass procedure, e.g., duodenojejunostomy. SUMMARY
We have reviewed 32 cases of preduodenal portal vein, including our three new cases. Duodenal obstruction was the most frequent indication for surgery. The etiology of obstruction can be the ectopic portal vein, but many other congenital duodenal causes are reported. Malrotations, situs inversus, and a variety of cardiovascular lesions have been associated with preduodenal portal vein. It is also important to recognize the portal vein because of the potential technical problems.
554
BOWERAND TERNBERG REFERENCES
1. Knight, H. 0.: An anomalous portal vein with its surgical dangers. Ann. Surg. 74:697,1921. 2. His, W.: Human anatomy and embryology. III. Organ histology (in German). Leipzig, Vogel, 1685,pp. l-260. 3.Begg, A. S.: The anomalous persistence in embryos of part of the periintestinal rings
formed by the vitellme veins. Amer. J. Anat, 13:103, 1912. 4. Marks, C.: Developmental basis of the portal venous system. Amer. J. Surg. 117: 671,l(i69. 5. Dott, N. M.: Anomalies of intestinal rotation. Brit. J. Surg. 11:251,1923.
Riscussion Dr. 7. ZIoiren (Atlanta): I would like to know where the superior mesenteric artery and colon were in relationship to the portal vein. Was this a reversed malrotation, as the other patients had? Dr. Botoer: In two of our cases, the superior mesenteric artery was in its normal position passing over the fourth portion of duodenum. In one of our cases there was a “reverse” rotation, the definition of this being that the duodenum passes over the superior mesenteric artery whereas the transverse colon passes under it.
W
E HAVE ENCOUNTERED three examples of preduodenal portal vein during the past year. Twenty-nine cases of this anomaly were documented in reviewing the literature. Analysis of these cases emphasizes that the anomaly has a high association with other congenital anomalies, and that a preduodenal portal vein in some instances may be a cause of duodenal obstruction. Potential technical hazards. make it important that this entity be recognized. CASE HISTORIES
Case 1, E.W. A 3-yr-old black girl was transferred to St. Louis Children’s Hospital with a history of intermittent vomiting. The patient had a long history of poor growth and frequent respiratory tract infections. A diagnosis of malrotation was made on the upper gastrointestinal roentgen examination. At operation, reverse rotation was found. The left lobe of the liver was larger than the right and the gallbladder was to the left of the falciform ligament, In addition, the portal vein was anterior to the first portion of the duodenum, which was found to be entirely intraperitoneal. The portal vein was causing partial obstruction. An end-to-end duodenoduodenostomy was performed. This placed the portal vein dorsal to the duodenum. The child has done weI1. In addition to the abdominal anomalies, the child has a right aortic arch with an aberrant left subclavian artery forming a loose vascular ring.
Case 2, R.S. A &day-old white female infant was transferred to St. Louis Children’s Hospital with a one-day history of bilious vomiting. Abdominal roentgenological showed a large amount of air in the stomach but little air in the remainder of the gastrointestinal tract. A barium enema showed a colon of normal calibre with the cecum in the right lower quadrant. However, most of the colon was in the right abdomen. The upper gastrointestinal radiologic examination showed high-grade duodenal obstruction with an anteriorly placed duodenum. This picture suggested “reverse rotation.” At operation the duodenum was intraperitoneal as in case 1. The portal vein passed anterior (ventral) to the first portion of the duodenum, but was not causing any obstruction. A duodenal web in the third portion of the duodenum was found. The web was excised. The patient was reoperated upon at age 2 wk for intestinal obstruction secondary to adhesions. She was discharged 7 days later and on subsequent follow-up has done well.
Case 3, A.P. A s-day-old premature Louis Children’s Hospital
black female infant weighing 2100 g was transferred to St. because of jaundice, abdominal distension, and vomiting, A
From the Department of Surgery, Washington Uninersity School of Medicine, and St. Hospital, Sf. Louis, MO. Presented at the Third Annual Meeting of the American Pediatric Surgical Association, Hot Springs, Vu., April 13-15, 2972. Richard J. Bower, M.D.: St. Louis Children’s Hospital, St. Louis, MO. Jessie L. Ternberg, M.D.: Departmenf of Surgery, Washington University School of Medicine, St. Louis, MO. Louis Children’s
&wnal Of F’edietriCsurgery. Vol. 7, No. 5 (October-November), 1972
579
580
BOWER AND TERNBERG
grade IV/VI systolic murmur was heard over the entire left chest. The Iiver was enlarged. A chest film showed pulmonary overcirculation, and an upper gastrointestinal radiological examination showed duodenal obstruction with evidence of malrotation. At operation the liver was enlarged and congested. The small bowel was collapsed. Ladd’s bands in the right upper quadrant were lysed. However, the duodenal obstruction was caused by the portal vein, which passed in front of the first portion of the duodenum and then behind the distal duodenum. The pancreas was present as a globular structure on the right side of the duodenum. We divided the proximal duodenum and performed end-to-end duodenoduodenostomy, placing the portal vein dorsal to the duodenum. Cardiac catheterization showed a double-outlet right ventricle. The child is now 6 mo old and doing poorly with heart failure.
DISCUSSION The first report of a preduodenal portal vein was made by Knight’ in 1921. He found this anomaly in a dissecting-room cadaver. However, the theory to account for such an occurrence was first put forth by His in 1885,2 and an
A
B
5 Weeks
6 Weeks
5 Weeks
6 Weeks
10 Weeks
10 Weeks
Fig. 1. (A) Normal development of portal vein. (6) Possible explanation of preduodenal portal vein.
PREDUODENALPORTALVEIN
581
example of this anomaly in a pig embryo was reported in 1912.3 Marks has recently reviewed the development of the portal venous system.4 Two vitelline veins and their three anastomotic connections eventually form the portal vein. There are thus at an early stage two rings of vascular tissue around the gastrointestinal tract, as described by His and since referred to as the “periintestinal ring theory.“ A portion of each ring degenerates and leaves the portal vein. This development occurs during the fifth to tenth weeks. The development is schematically shown in Fig. 1A. During the fifth week there are three connections between the veins. The developing duodenum passes anterior (ventral) to the second bridging anastomosis and posterior (dorsal) to the third. The first bridge lies within the liver. During the sixth week the proximal portion of the left vitelline vein and the distal portion of the right vitelline vein begin to regress. The second vascular bridge enlarges and persists as the portal vein and passed behind or dorsal to the duodenum. At 10 wk a single vein has been formed from the vitelline veins. To explain the occurrence of a preduodenal or ventral portal vein several events must occur, as illustrated in Fig. IB. The second anastomotic bridge begins to obliterate at the sixth week and the third bridge begins to enlarge. The portal vein is thus composed of the right vitelline vein and the third bridge (instead of the second), which passes anterior or ventral to the duodenum. The continuation of the portal vein and its bifurcation into splenic and superior mesenteric veins may be dorsal or ventral to the fourth duodenum. The 29 cases from the literature plus our three patients are summarized in Table 1. Twenty-two of the cases had the preduodenal portal vein discovered at operation; the other ten cases were anatomic descriptions of necropsy findings. Nineteen cases presented with acute or chronic intestinal obstruction originating above the ligament of Treitz. Four were adults who had long histories of epigastric complaints secondary to chronic gastric outlet obstruction. The etiology of the obstruction was the preduodenal portal vein in ten cases (Fig. 2). Other causes of the obstruction included duodenal atresia, doudenal stenosis, duodenal web, annular pancreas, malrotation, or a combination of these
Portal Vein 0
Fig. 2. Reported cases of preduodenal portal vein with intestinal struction.
ob-
@
v had $&%.ol Portal Vein as caure of obstruction
Portal Vein
BOWER AND TERNBERG
I Table 1. Cases Presenting With Intestinal Obstruction The complete bibliography may be obtained from Jessie L. Ternberg, M.D., Washington University School of Medicine, Department of Surgery, 4960 Audubon Ave., St. Louis, MO. 63110.
583
PREDUODENAL PORTAL VEIN Table 2. Anomalies
Reported in Patients with Preduodenal Portal Vein
Malrotations (incomplete, reverse, nonrotation, fixational Situs lnversus (partial or complete) Pancreatic anomalies (annular, ventral, no tail) Duodenal anomalies (atresia, stenosis, web) Biliary system anomalies (atresia, ectopic CBD) Sp!enic anomalies (multiple, bilobed, asp!enia) Dextrocardia Dextroposition of aorta VSD Persistent (L) SVC Vascular ring Double outlet (R) ventricle A-V communis Hypoplastic arch Sacral agenesis
errors)
23 9 8 8 8 6 5 3 2 2 1 1 1 1 1
anomalies. Of the ten cases in which the preduodenal portal vein was considered to have caused the obstruction, four had an associated anomaly that could also be a possible cause of obstruction. It is important, therefore, after recogrizing and treating the more common causes of duodenal obstruction, to be sure that the preduodenal portal vein is not also contributing to the obstruction. Our third patient is an example of this. Additional anomalies were present in many of the 32 cases (Table 2). The most commonly occurring anomaly was “malrotation” (23 cases). In the group of “malrotations” we have included the wide spectra of rotational and fixational errors that have been well described by Dott.5 Partial or complete situs inversus was another frequent finding (nine cases). Pancreatic and duodenal anomalies were also frequent. Only one of these patients was reported to have trisomy 21. There were 16 cardiovascular lesions in 11 patients, but only dextrocardia and dextroposition of the aorta occurred three times or more. Surgical therapy consists primarily of the treatment of associated anomalies. If the preduodenal portal vein causes the obstruction, the surgical procedure can be either an end-to-end duodenoduodenostomy (placing the portal vein in its normal dorsal position), or a bypass procedure, e.g., duodenojejunostomy. SUMMARY
We have reviewed 32 cases of preduodenal portal vein, including our three new cases. Duodenal obstruction was the most frequent indication for surgery. The etiology of obstruction can be the ectopic portal vein, but many other congenital duodenal causes are reported. Malrotations, situs inversus, and a variety of cardiovascular lesions have been associated with preduodenal portal vein. It is also important to recognize the portal vein because of the potential technical problems.
554
BOWERAND TERNBERG REFERENCES
1. Knight, H. 0.: An anomalous portal vein with its surgical dangers. Ann. Surg. 74:697,1921. 2. His, W.: Human anatomy and embryology. III. Organ histology (in German). Leipzig, Vogel, 1685,pp. l-260. 3.Begg, A. S.: The anomalous persistence in embryos of part of the periintestinal rings
formed by the vitellme veins. Amer. J. Anat, 13:103, 1912. 4. Marks, C.: Developmental basis of the portal venous system. Amer. J. Surg. 117: 671,l(i69. 5. Dott, N. M.: Anomalies of intestinal rotation. Brit. J. Surg. 11:251,1923.
Riscussion Dr. 7. ZIoiren (Atlanta): I would like to know where the superior mesenteric artery and colon were in relationship to the portal vein. Was this a reversed malrotation, as the other patients had? Dr. Botoer: In two of our cases, the superior mesenteric artery was in its normal position passing over the fourth portion of duodenum. In one of our cases there was a “reverse” rotation, the definition of this being that the duodenum passes over the superior mesenteric artery whereas the transverse colon passes under it.