Precise hepatectomy guided by the middle hepatic vein

The middle hepatic vein (MHV) lies in the midplane of the liver. The classical teaching of right or left hepatectomy is transection of liver I cm to the right or left wall of the MHV in order to avoid bleeding. However, guidance of liver transection is lost if the course of the MHV is not known. By exposing the MHV early in the phase of liver transection and following its course to the inferior vena cava, a precise liver transection plane could be obtained. Such technique has the potential of achieving adequate tumor-free resection margin, avoiding damage to intrahepatic portal pedicles, preserving venous drainage and functional liver tissue, and less postoperative infection.

Management of the middle hepatic vein and its tributaries in right lobe living donor liver transplantation

BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the right lobe has become a standard method for adult patients. As the drainage of the median sector (segments V, VIII and IV) is mainly by the middle hepatic vein (MHV), the issue of whether the MHV should or should not be taken with the graft or whether the MHV tributaries (V5, V8) should be reconstructed in the recipient remains to be settled. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1985-2006) on right lobe living donor liver transplantation, middle hepatic vein, vein graft, hepatic venoplasty and other related subjects. RESULTS: Some institutions had proposed their policy for the management of the MHV and its tributaries. Dominancy of the hepatic vein, graft-to-recipient weight ratio, and remnant liver volume as well as the donor-to-recipient body weight ratio, the volume of the donor's right lobe to the recipient's standard liver volume and the size of MHV tributaries are the major elements for the criteria of inclusion of the MHV, while for the policy of MHV tributaries reconstruction, the proportion of congestive area and the diameter of the tributaries are the critical elements. Optimal vein grafts such as recipient's portal vein and hepatic venoplasty technique have been used to obviate hepatic congestion and venous drainage disturbance. CONCLUSIONS: Taking right liver grafts with the MHV trunk (extended right lobe grafts) or performing the MHV tributaries reconstruction in modified right lobe grafts, according to the criteria proposed by the institutions with rich experience, can solve the congestion problem of the right paramedian sector and help to improve the outcomes of the patients. The additional use of optimal vein grafts and hepatic venoplasty also can guarantee excellent venous drainage.

Efficacy of middle hepatic vein reconstruction in adult right-lobe living donor liver transplantation

BACKGROUND: Congestion of the right anterior segment may lead to graft dysfunction in right-lobe living donor liver transplantation (LDLT) without a middle hepatic vein (MHV) trunk. Selective reconstruction of MHV tributaries with the interposition of vascular grafts has been introduced to overcome this problem. However, there is still no consensus on the definite criteria of MHV reconstruction. METHODS: LDLT patients were reviewed to evaluate the effects of MHV reconstruction. From March 2005 to September 2008 in our transplantation center, 120 consecutive LDLTs were performed using a right-lobe graft without a MHV. Excluding 11 patients, among the remainder, 73 (67%) had reconstructed MHV tributaries, and the others 36 (33%) did not. The values of liver functional index and liver graft regeneration ratio were compared between the two groups. RESULTS: There was a prolonged period of liver functional recovery in patients with small-for-size grafts and a graft-recipient weight ratio (GRWR) <1.0%, and without MHV reconstruction. The ratio of liver regeneration 1 month postoperatively in reconstruction cases was 81%, versus 78% in patients without reconstruction (P=0.352), but among small-for-size grafts, there was a significant difference between the two groups (95% vs. 80%). CONCLUSION: Our study shows that reconstruction of MHV tributaries is not necessary in all patients, but is beneficial for patients with GRWR <1.0%. (Hepatobiliary Pancrent Dis Int 2010; 9: 135-138)

Management of the Middle Hepatic Vein in Right Lobe Living Donor Liver Transplantation: A Meta-analysis

Summary： Living donor liver transplantation （LDLT） is a curative treatment for end stage liver disease. It is advantageous due to the shortage of deceased donors. However, in LDLT, whether the middle he- patic vein （MHV） should be preserved in donors remains controversial. We conducted searches in Pub- reed, Embase, Cochrane Library, Web of Science, Ovid, and Google Scholar using the key words ＂living donor liver transplantation＂ and ＂middle hepatic vein＂. Due to ethical issues, there were no randomized control trails focusing on MHV in LDLT. The majority of reports were retrospective studies. We exam- ined the reference lists to identify related investigations. Google Scholar was then used to obtain full texts. Nine observational studies were analyzed. There were no significant differences in liver function （WMD, -5.51; P=0.12） and complications （RR, 0.98; P=0.89） in donors with or without MHV. How- ever, the liver function in recipients was greatly improved after LDLT with MHV （WMD, -78.32; P=0.01）. No definite conclusion was obtained in terms of the liver regeneration indices between LDLT with or without MHV. It was conclude that grafts with MHV in LDLT favor recipient outcomes and do not harm the living donor if a careful preoperative evaluation is oerformed.

Reconstruction of the middle hepatic vein tributary in adult right lobe living donor liver transplantation

BACKGROUND: In adult-to-adult living donor liver transplantation (LDLT), the use of a right lobe graft without the middle hepatic vein (MHV) can cause hepatic congestion and disturbance of venous drainage. To solve this problem, we successfully used cadaveric venous allografts preserved in 4 ℃ University of Wisconsin (UW) solution within 10 days as interposition veins for drainage of the paramedian portion of the right lobe in adult LDLT. METHODS: From June 2007 to January 2008, 11 adult LDLT patients received modified right liver grafts. The major MHV tributaries (greater than 5 mm in diameter) of 9 cases were preserved and reconstructed using cadaveric interposition vein allografts that had been stored for 1 to 10 days in 4 ℃ UW solution. The regeneration of the paramedian sector of the grafts and the patency of the interposition vein allografts were examined by Doppler ultrasonography after the operation. RESULTS: MHV tributaries were reconstructed in 9 recipients. Only 1 recipient died of renal failure and severe pulmonary infection on day 9 after transplantation without any hemiliver venous outflow obstruction. The other 8 recipients achieved long-term survival with a median follow-up of 30 months. The cumulative patency rates of the 8 recipients were 63.63% (7/11), 45.45% (5/11), 45.45% (5/11) and 36.36% (4/11) at 3, 6, 12 and 24 months, respectively. Regeneration of the paramedian sectors was equivalent.CONCLUSION: The cadaveric venous allograft preserved in 4 ℃ UW solution within 10 days serves as a useful alternative for interposition veins in facilitating implantation of a right lobe graft and guarantees outflow of the MHV.

Absent middle hepatic vein in a right liver graft donor

BACKGROUND: The middle hepatic vein (MHV) is normally in form of a large trunk lying within the midplane of the liver. An anomaly in form of two separate trunks, each draining segment V/VIII and segment IV, has been described by Couinaud but not been well documented in the literature. METHOD: We report a right liver donor in whom the MHV was absent and not encountered during liver transection along the midplane of the liver. RESULTS: On computed tomography (CT) scan and intraoperative ultrasonography, there was a large segment VIII hepatic vein mistaken as the MHV on preoperative assessment and a large segment IV hepatic vein close to the ligamenturn venosum. CT volumetry based on either segment VIII or IV hepatic vein led to major error in liver volume calculation. Transection of the liver guided by segment VIII or IV hepatic vein would lead to sacrifice of liver parenchyma unnecessarily or presence of necrotic liver in the graft. CONCLUSION: Absent MHV is a rare anomaly. It is revealed by careful study of the CT scan.

Color Doppler ultrasonographic assessment of the risk of injury to major branch of the midddle hepatic vein during laparoscopic cholecystectomy

OBJEGTIVE: To investigate the causes of hemorrhage from the gallbladder bed during laparoscopic cholecystectomy. METHODS: 617 patients who had received laparoscopic cholecystectomy from September, 2000 to March, 2001 at this hospital were reviewed retrospectively. Ninety-one of these patients were selected randomly for prospective observation. Color Doppler ultrasound was used to examine the cause of venous hemorrhage from the gallbladder bed during laparoscopic cholecystectomy and to examine the anatomic relationship between the gallbladder bed and the branches of the middle hepatic vein in 91 patients preoperatively. RESULTS: A large branch of the middle hepatic vein extended closely behind the gallbladder bed in all 91 patients. The mean distance between the closest point (C point) of this branch to the gallbladder bed was 5.0±4.6 mm. The branch of the middle hepatic vein was completely adherent to the gallbladder bed in 14 (15.38%) of the 91 patients. The distance between this branch and the gallbladder bed was within I mm in 10 (10.99%) of the 91 patients. The inside diameter at C point of this branch was 3.2±1.1 mm. The C point was found on the left side of the longitudinal axis of the gallbladder in 31 (34.66%) of the 91 patients, on the right side in 39 patients (42.86%), just on the axis in 21 patients (23.08%). The venous blood flow rate at the C point was 9.9±3.3 cm/s. CONCLUSIONS: A large branch of the middle hepatic vein passes behind the gallbladder. The inside diameter of this branch is relatively larger. The bleeding of this branch during operation can only be stopped by transfixion. The closest point of this vein to the gallbladder is mostly situated on the right side of the longitudinal axis of the gallbladder. Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of hemorrhage during laparoscopic cholecystectomy and should be identified preoperatively with ultrasound.

Protection of the liver during partial hepatectomy

BACKGROUND: Liver failure is the most common cause of mortality for patients undergoing partial hepatectomy. Given adequate liver function and remnant liver volume and absence of co-morbid illness, the cause of liver failure is frequently related to technical errors, which induces mas- sive bleeding and ischemic damage to the liver remnant. DATA RESOURCES: From author' s practice at Queen Mary Hospital, the University of Hong Kong. RESULTS: To avoid technical errors leading to liver ische- mia and failure, adequate exposure, control of bleeding during liver transection, and planning of transection plane are important. Ultrasonic dissector is the best instrument in liver transection. Its careful use can reduce blood loss and help recognize the hepatic vein, the exposure of which serves as an important landmark for a correct transection plane. Even without Pringle maneuver, minimum bleeding during transection could be achieved. CONCLUSION: Protection of the liver remnant is impor- tant to patient survival after partial hepatectomy. It is achieved by meticulous surgical techniques that reduce bleeding to a minimum.