Restitution of Bile Duct After Ligation and Excision in Rhesus Monkeys By Mohandas
Devadas,
Alexander
Templeton,
and Arnold
S. Leonard
N THE COURSE OF EXPERIMENTAL PROCEDURES to produce a model of biliary atresia in rhesus monkeys it was observed that some animals recovered spontaneously from obstructive jaundice within a period of 4 to 6 wk. Few animals that died during the third postoperative week showed macroscopic and microscopic evidence of proliferation of bile ducts at the site of division.
I
MATERIALS
AND
METHODS
Six rhesus monkeys less than a year of age weighing between 4 and 5 kg were used for the study. They were quarantined for a period of 3 wk to rule out any existing infections. Serum bilirubin was estimated weekly. Liver biopsy was done preoperatively. at operation, postoperatively, and after return of bilirubin levels to normal. Anesthesia, induced with Ketalar and Nembutal. was similar in all the animals. Under aseptic conditions, the abdomen was opened by a midline incision. The gallbladder and the common bile duct were identified. The gallbladder was removed with the cystic duct. The hepatic ducts were ligated. The common bile duct was ligated just above the junction of the cystic duct. Second ligature was placed on the CBD just above the duodenum. The intervening segment of the CBD was excised and the divided ends were stick tied. The portal area was searched for the presence of any accessory ducts that might dilate when the main duct was obstructed. Liver biopsy was taken, and the wound closed in layers. During the third week after the onset of obstructive jaundice, internal drainage of the thoracic duct into a loop of jejunum was instituted with a Cordis-Hakim valve following the method previously described.5 The animals were followed for 2 mo or until death. RESULTS
The serum bilirubin levels in the animals at 2 wk and 2 mo after operation are shown in Table 1. Within the 2-mo period, three of the six monkeys had completely recovered from obstructive jaundice and liver biopsy showed no evidence of fibrotic changes. In these monkeys, an exploratory laparotomy during the fifth month showed an apparently normal reconstituted bile duct which was confirmed by an operative cholangiogram. Three of the other animals died within 48 hr of construction of the internal drainage of the thoracic duct. Autopsy revealed marked biliary retention most prominent at the porta hepatis. There was a thick fibrous cord that extended from distended bile ducts at the hilum of the liver to the supraduodenal portion of the original bile duct. Biopsy of the fibrous cord showed islands of epithelium amid a stroma of fibrous tissue suggesting that the bile duct was in the process of restitution. -. From the Department of Pathology and Pediatric Surgery. University of Minnesota. Minneapolis. Minn. Address for reprint requests: Alexander C. Templeton. M.D.. The St. Vincent Hospital r!f’ Worce.tter. Worcester. Mass. 016 IO. G 1975 bv Grune & Stratton, Inc.
Journal of Pediatric Surgery, Vol. 10, No. 4 (August), 1975
511
512
DEVADAS,
Table I.
Progress of Serum Bilirubin
TEMPLETON,
AND
LEONARD
Levels 2 wk and 2 mo After Surgery Serum
2 Weeks After CBD Obstruction
Bilirubin 2 Months After CBD Obstruction Dir
Total
12.1
0.3
0.5
4.7
0.08
0.8
Monkey No.
D1r
Total
26
4.5
27
1.4
28
5.0
13.7
Postoperative death Postoperative death
29
5.4
16.5
30
5.0
14.3
31
6.1
11.4
Postoperative death 0.0
1
0.1
DISCUSSION
The construction of a shunt between the thoracic duct and the jejunum was designed to utilize a potential for excretion of bile.lm4 By diverting the fluid into the bowel it was hoped to preserve protein and enable binding of excessive bile salts by cholestyramine. Regeneration of the bile duct in spite of extensive resection was an unexpected occurrence in half the animals. The capacity of the bile duct to reconstitute itself after ligation has been noted in a number of species. This happening was first recognized by Benjamin Brodie (cited by Cameron’j) in 1823. In 1926, Bell (cited by Cameron6) noted regeneration of the bile duct after ligation, in dogs. A completely divided common bile duct in rats may undergo reconstruction so that there is reestablishment of biliary flo~.~,’ The liver then returns to its normal condition. The occurrence of restitution of bile ducts in Rhesus monkeys which have been ligated at two points with excision of intervening segment, has not been previously reported. This capacity of bile duct epithelium to bridge a considerable gap and effect a complete restoration of flow should encourage a conservative approach to similar situations such as atresia of the extrahepatic ducts occuring in man. Kasai et al’ in a study of extrahepatic bile ducts in 30 cases of biliary atresia, found that tiny but patent bile ducts existed in the fibrous mass at the porta hepatis in the majority of cases in which no patent hepatic duct was recognized grossly. These tiny bile ducts could not be proved to connect with the bile capillaries by the histologic studies. Berenson et aL9 reported a case of a girl who at 12 wk of age underwent cholangiojejunostomy for treatment of complete atresia of the bile duct. Twenty-five years after operation she was alive and a cholangiogram revealed a well-formed bile duct. Hays et al.” found cord-like biliary tract structures in a group of patients with obstructive neonatal jaundice. They recorded spontaneous recovery of infants, considered to have had biliary atresia diagnosed by liver biopsy, cholangiogram, or both. Unequivocal restitution of the bile duct in human beings has not been reported. It seems highly probable that reconstitution of the bile duct could occur in humans and the possibility of its occurrence should be kept in mind in the management of biliary obstruction. SUMMARY
Restitution of the bile duct occurred after ligation of the original duct at two points with excision of a 2-cm segment between the ligatures in three of six
RESTITUTION
OF BILE DUCT
513
animals so treated. Complete functional restitution was confirmed by liver biopsy, serum bilirubin estimations, and cholangiogram. Partial regeneration was noted in three monkeys which died 17 days after the ligation and excision of the original bile duct. REFERENCES I. Alican F, Hardy JD: Lymphatic transport of bile pigments and alkaline phosphatase in experimental common duct obstruction. Surgery 52:366. 1962 2. Shafiroff BGP. Doubilet M. Ruggiero W: Bilirubin absorption in obstructive jaundice. Proc Sot Exp Biol Med 42:203, 1939 3. Johnson LE. Mann FC: Intrahepatic lymphatics. Am J Physiol63:723. 1950 4. Dumont AE, Mulholland JH: Alterations in thoracic duct lymph flow in hepatic cirrhosis. Ann Surg 156:668, 1962 5. Devadas M: Selective experiments on the lymphatics of the liver and thoracic duct. M.S. Thesis, 1974. Univ. of Minnesota 6. Cameron
GR. Oakley
CL: Ligature
of the
common bile duct. J Pathol Bacterial 35.769. 1932 7. Cameron GR, Prasad LBM: Recovery from biliary obstruction after spontaneous restoration of the obstructed common bile duct. J Pathol Bacterial 80: 127. 1968 8. Kasai M, Kimuro S, Asakuro Y. et al: Surgical treatment of biliary atresia. J Pediatr Surg 3:665. 1968 9. Berenson MM, Garde AR, Moody RC; Twenty-five year survival after surgery for complete extrahepatic biliary atresia. Castroenter-. ology 66:260. 1974 10. Hays DM, Wooley MM, Synder WH, et al: Diagnosis of biliary atresia: Relative at:curacy of percutaneous liver biopsy, open liver biopsy, and operative cholangiography. J Pediatr 71:598, 1967
Devadas,
Alexander
Templeton,
and Arnold
S. Leonard
N THE COURSE OF EXPERIMENTAL PROCEDURES to produce a model of biliary atresia in rhesus monkeys it was observed that some animals recovered spontaneously from obstructive jaundice within a period of 4 to 6 wk. Few animals that died during the third postoperative week showed macroscopic and microscopic evidence of proliferation of bile ducts at the site of division.
I
MATERIALS
AND
METHODS
Six rhesus monkeys less than a year of age weighing between 4 and 5 kg were used for the study. They were quarantined for a period of 3 wk to rule out any existing infections. Serum bilirubin was estimated weekly. Liver biopsy was done preoperatively. at operation, postoperatively, and after return of bilirubin levels to normal. Anesthesia, induced with Ketalar and Nembutal. was similar in all the animals. Under aseptic conditions, the abdomen was opened by a midline incision. The gallbladder and the common bile duct were identified. The gallbladder was removed with the cystic duct. The hepatic ducts were ligated. The common bile duct was ligated just above the junction of the cystic duct. Second ligature was placed on the CBD just above the duodenum. The intervening segment of the CBD was excised and the divided ends were stick tied. The portal area was searched for the presence of any accessory ducts that might dilate when the main duct was obstructed. Liver biopsy was taken, and the wound closed in layers. During the third week after the onset of obstructive jaundice, internal drainage of the thoracic duct into a loop of jejunum was instituted with a Cordis-Hakim valve following the method previously described.5 The animals were followed for 2 mo or until death. RESULTS
The serum bilirubin levels in the animals at 2 wk and 2 mo after operation are shown in Table 1. Within the 2-mo period, three of the six monkeys had completely recovered from obstructive jaundice and liver biopsy showed no evidence of fibrotic changes. In these monkeys, an exploratory laparotomy during the fifth month showed an apparently normal reconstituted bile duct which was confirmed by an operative cholangiogram. Three of the other animals died within 48 hr of construction of the internal drainage of the thoracic duct. Autopsy revealed marked biliary retention most prominent at the porta hepatis. There was a thick fibrous cord that extended from distended bile ducts at the hilum of the liver to the supraduodenal portion of the original bile duct. Biopsy of the fibrous cord showed islands of epithelium amid a stroma of fibrous tissue suggesting that the bile duct was in the process of restitution. -. From the Department of Pathology and Pediatric Surgery. University of Minnesota. Minneapolis. Minn. Address for reprint requests: Alexander C. Templeton. M.D.. The St. Vincent Hospital r!f’ Worce.tter. Worcester. Mass. 016 IO. G 1975 bv Grune & Stratton, Inc.
Journal of Pediatric Surgery, Vol. 10, No. 4 (August), 1975
511
512
DEVADAS,
Table I.
Progress of Serum Bilirubin
TEMPLETON,
AND
LEONARD
Levels 2 wk and 2 mo After Surgery Serum
2 Weeks After CBD Obstruction
Bilirubin 2 Months After CBD Obstruction Dir
Total
12.1
0.3
0.5
4.7
0.08
0.8
Monkey No.
D1r
Total
26
4.5
27
1.4
28
5.0
13.7
Postoperative death Postoperative death
29
5.4
16.5
30
5.0
14.3
31
6.1
11.4
Postoperative death 0.0
1
0.1
DISCUSSION
The construction of a shunt between the thoracic duct and the jejunum was designed to utilize a potential for excretion of bile.lm4 By diverting the fluid into the bowel it was hoped to preserve protein and enable binding of excessive bile salts by cholestyramine. Regeneration of the bile duct in spite of extensive resection was an unexpected occurrence in half the animals. The capacity of the bile duct to reconstitute itself after ligation has been noted in a number of species. This happening was first recognized by Benjamin Brodie (cited by Cameron’j) in 1823. In 1926, Bell (cited by Cameron6) noted regeneration of the bile duct after ligation, in dogs. A completely divided common bile duct in rats may undergo reconstruction so that there is reestablishment of biliary flo~.~,’ The liver then returns to its normal condition. The occurrence of restitution of bile ducts in Rhesus monkeys which have been ligated at two points with excision of intervening segment, has not been previously reported. This capacity of bile duct epithelium to bridge a considerable gap and effect a complete restoration of flow should encourage a conservative approach to similar situations such as atresia of the extrahepatic ducts occuring in man. Kasai et al’ in a study of extrahepatic bile ducts in 30 cases of biliary atresia, found that tiny but patent bile ducts existed in the fibrous mass at the porta hepatis in the majority of cases in which no patent hepatic duct was recognized grossly. These tiny bile ducts could not be proved to connect with the bile capillaries by the histologic studies. Berenson et aL9 reported a case of a girl who at 12 wk of age underwent cholangiojejunostomy for treatment of complete atresia of the bile duct. Twenty-five years after operation she was alive and a cholangiogram revealed a well-formed bile duct. Hays et al.” found cord-like biliary tract structures in a group of patients with obstructive neonatal jaundice. They recorded spontaneous recovery of infants, considered to have had biliary atresia diagnosed by liver biopsy, cholangiogram, or both. Unequivocal restitution of the bile duct in human beings has not been reported. It seems highly probable that reconstitution of the bile duct could occur in humans and the possibility of its occurrence should be kept in mind in the management of biliary obstruction. SUMMARY
Restitution of the bile duct occurred after ligation of the original duct at two points with excision of a 2-cm segment between the ligatures in three of six
RESTITUTION
OF BILE DUCT
513
animals so treated. Complete functional restitution was confirmed by liver biopsy, serum bilirubin estimations, and cholangiogram. Partial regeneration was noted in three monkeys which died 17 days after the ligation and excision of the original bile duct. REFERENCES I. Alican F, Hardy JD: Lymphatic transport of bile pigments and alkaline phosphatase in experimental common duct obstruction. Surgery 52:366. 1962 2. Shafiroff BGP. Doubilet M. Ruggiero W: Bilirubin absorption in obstructive jaundice. Proc Sot Exp Biol Med 42:203, 1939 3. Johnson LE. Mann FC: Intrahepatic lymphatics. Am J Physiol63:723. 1950 4. Dumont AE, Mulholland JH: Alterations in thoracic duct lymph flow in hepatic cirrhosis. Ann Surg 156:668, 1962 5. Devadas M: Selective experiments on the lymphatics of the liver and thoracic duct. M.S. Thesis, 1974. Univ. of Minnesota 6. Cameron
GR. Oakley
CL: Ligature
of the
common bile duct. J Pathol Bacterial 35.769. 1932 7. Cameron GR, Prasad LBM: Recovery from biliary obstruction after spontaneous restoration of the obstructed common bile duct. J Pathol Bacterial 80: 127. 1968 8. Kasai M, Kimuro S, Asakuro Y. et al: Surgical treatment of biliary atresia. J Pediatr Surg 3:665. 1968 9. Berenson MM, Garde AR, Moody RC; Twenty-five year survival after surgery for complete extrahepatic biliary atresia. Castroenter-. ology 66:260. 1974 10. Hays DM, Wooley MM, Synder WH, et al: Diagnosis of biliary atresia: Relative at:curacy of percutaneous liver biopsy, open liver biopsy, and operative cholangiography. J Pediatr 71:598, 1967
