Case 1
A 58-year-old female was admitted due to discomfort in the right upper quadrant of abdomen for over 20 years. Physical examination showed no abnormality. Liver function tests were normal (Child–Pugh A grade). Contrast-enhanced CT and MRI of liver demonstrated bilateral diffuse hepatolithiasis and atrophy in left and right lobes with exceeding hypertrophy of caudate lobe. There was no evidence of stricture in extrahepatic bile duct (Fig. 1). The volume of hypertrophic caudate lobe was 68.4% according to 3-dimentional reconstruction of CT scan.
Case 2
A 63-year-old male presented with a 17-year history of right upper abdominal pain and intermittent fever. Past medical history included a choledochocystectomy with bilioenterostomy 24 years ago. Mild jaundice was observed. Liver function tests showed a serum total bilirubin of 51.7 mmol/L, alkaline phosphatase of 142 μmol/L, γ-GT of 245 μmol/L, indicating biliary obstruction (Child–Pugh A grade). The results of contrast-enhanced CT and MRI were similar to case 1 and RLV was 65.8% (Fig. 2).
Atrophy–hypertrophy complex
Contrast CT was used for the evaluation of AHC. Normally, the short hepatic veins draining the caudate lobe are too tiny to be seen on CT images. But under the condition of exceeding caudate lobe hypertrophy, its short hepatic veins caudal to the hepatic veins of the main liver become thick and usually run in the middle of hypertrophic caudate lobe, which could be easily identified by CT images. Moreover, the location of these short hepatic veins could indicate which part of the caudate lobe is hypertrophic. If these short hepatic veins are on the left side of IVC (inferior vena cava), it indicates the hypertrophy of the Spiegel lobe. On this occasion, the atrophic main liver will rotate counterclockwise towards right side, while the hepatic hilum might rotate to the dorsal of the abdominal cavity, resulting in difficulty to dissect the hilum (Case 1, Fig. 1). On the contrary, if these short hepatic veins located on the right side of IVC, the hypertrophy of the paracaval portion and caudate processus would push the main liver clockwise rotating towards left side (Case 2, Fig. 2), resulting the hepatic hilum become more superficial.
Configuration of the vasculatures
Contrast CT along with 3D liver reconstruction was employed to evaluate configuration or variation of the vasculature system, especially the blood supply or bile drainage of caudate lobe. In case 1, the artery and portal vein of caudate lobe that originate from left hepatic artery (LHA) and left portal vein (LPV) respectively were prone to be observed, but it was difficult to identify the undilated bile duct of caudate lobe in 3D images (Fig. 3). In case 2, 3D images showed that the artery, portal vein and bile duct of caudate lobe originated from right hepatic artery (RHA), main portal vein and confluence of right and left hepatic ducts respectively (Fig. 4).
Treatment
Operation was started with a right subcostal reversed L-shaped incision. Intraoperative exploration: In case 1, the caudate lobe was extremely hypertrophic with normal texture, while the segment II- VIII were atrophic and contained a large amount of bile pigment stones (Fig. 5). There were severe adhesions between atrophic liver and diaphragm or IVC. The diameter of common bile duct was 1.5 cm. The distal bile duct was unobstructed with normal Oddi sphincter and the opening orifice of bile duct for caudate lobe was not stenosed. So caudate lobe-sparing subtotal hepatectomy and choledochoplasty with T tube drainage were performed (Additional file 1: Video 1).
In case 2, there were severe adhesions in the upper abdomen. The previous surgical procedure was hepaticojejunostomy. The segment II–VIII were atrophic with the left and right intrahepatic bile ducts filled with stones and pus (Fig. 6). The caudate lobe was hypertrophy with normal texture. So caudate lobe-sparing subtotal hepatectomy and hepaticojejunostomy were carried out.
Mobilization of the main liver
The liver was mobilized via dividing the contractual and dislocated falciform, triangular and coronary ligaments. By the use of low-power electric knife, meticulous layer-by-layer separation of the adhesions was performed to avoid deflecting to either diaphragm or liver parenchyma. Especially, in case 1 the Makuuchi ligament was divided to well expose IVC and transect the short hepatic vein from the right liver, while venous drainage of the caudate lobe was preserved.
Hepatic hilum exposure
The hepatic hilum was well exposed after dissection of hepatoduodenal ligament in case 1 or the previous intestinal loop for biliary-intestinal anastomosis in case 2. Cholecystectomy was performed after dissecting the Calot triangle in case 1. The previous biliary-intestinal anastomosis was removed in case 2.
Choledochoscopy
Choledochoscopy was employed through the common bile duct (CBD) in case 1 and the previous intestinal loop in case 2. No stones and strictures in the bile ducts of caudate lobe was observed in both cases and no dysfunction of Oddi sphincter in case 1.
Devascularization of the main liver and vasculature preservation of the caudate lobe
The hepatoduodenal ligament around porta hepatis was dissected firstly and the hepatic artery, portal vein, bile duct and their branches were exposed successively. And then the branches to caudate lobe could be preserved safely through cutting off and ligating the left and right hepatic artery, portal vein and bile duct at a safe point distal to the origin of the branches to caudate lobe (Figs. 5, 6).
Parenchymal transection
Liver parenchymal transection was performed with ultrasonic scalpel and cavitron ultrasonic surgical aspirator (CUSA), separating the hypertrophic caudate lobe and the atrophic main liver along their boundary. The left, middle and right hepatic veins were ligated and sutured with 5–0 Prolene.
Biliary drainage
T tube drainage was performed in CBD after choledochoplasty in case 1. Previous intestinal loop was used to reconstruct biliary-intestinal anastomosis in case 2.
Final diagnosis
Histopathological examination ruled out the potential malignancy. The final diagnosis for patient 1 was idiopathic hepatolithiasis with main liver atrophy and Spiegel lobe hypertrophy. And the diagnosis for patient 2 was hepatolithiasis secondary to previous choledochocystectomy with bilioenterostomy, leading to main liver atrophy combined with paracaval portion and caudate processus hypertrophy.
Outcome and follow-up
Operation time was 300 min and 360 min in two patients respectively, while blood loss was 200 ml and 300 ml. They were discharged at day 9 and 13 postoperatively without obvious complications such as bile leakage and liver dysfunction. The liver function tests, abdominal ultrasound and CT or MRI were performed at regular intervals during outpatient and telephone follow-up (Fig. 7). No evidence of liver dysfunction, hepatolithiasis recurrence or cholangitis was observed during the follow-up of 12 months in case 1 until she died of colon carcinoma. Until now, case 2 was uneventful without the above symptoms for 26 months.