Outflow reconstruction in right hepatic live donor liver transplantation

BACKGROUND: Inconstant venous anatomy increases the risk of outflow complications in right hepatic live donor liver transplantation (RH-LDT), but no consensus has emerged guiding optimal reconstruction for venous outflow. METHODS: We retrospectively analyzed surgical venous reconstruction using a flexible approach to anterior accessory veins in 48 RH-LDTs performed between April, 1998 and July, 2002. RESULTS: Actuarial recipient graft and patient survival was 79% and 85%, respectively. Single hepatic venous anastomosis was performed in 74% of the patients. Twelve patients underwent reconstruction of 20 accessory veins, including 7 posterior segment veins and 13 anterior segment veins. Anterior vein reconstruction techniques included end-to-end anastomosis to the middle hepatic vein, interposition conduit, venoplasty, or a combination of techniques. Documented complications related to the venous anastomosis occurred in only 1 patient (2%), with no patient having a documented venous thrombosis of either the main RHV or a reconstructed accessory vein. There were no differences in outcome based on single versus multiple venous reconstruction. Anteromedial congestion was noted in 3 patients in the absence of anatomic venous anastomotic complication, but the clinical significance of this finding is unclear. CONCLUSIONS: Despite variations in segmental venous drainage and a propensity for anteromedial congestion in right hepatic grafts, RH-LDT can be performed without outflow obstruction with close attention to a wide RHV anastomosis. In addition, anterior accessory vein reconstruction can be reserved for grafts of marginal size or quality where early postoperative venous congestion may impair early graft function. Routine extended hepatectomy incorporating the MHV with the graft is unnecessary.     

Donor graft outflow venoplasty in living donor liver transplantation.

Hepatic venous outflow reconstruction is a key to successful living donor liver transplantation (LDLT) because its obstruction leads to graft dysfunction and eventual loss. Inclusion or reconstruction of most draining veins is ideal to ensure graft venous drainage and avoids acute congestion in the donor graft. We developed donor graft hepatic venoplasty techniques for multiple hepatic veins that can be used in either right- or left-lobe liver transplantation. In left-lobe grafts, venoplasty consisting of the left hepatic vein and adjacent veins such as the left superior vein, middle hepatic vein, or segment 3 vein is performed to create a single, wide orifice without compromising outflow for anastomosis with the recipient's vena cava. In right lobe graft where a right hepatic vein (RHV) is adjacent with a significantly-sized segment 8 vein, accessory RHV, and/or inferior RHV, venoplasty of the RHV with the accessory RHV, inferior RHV, and/or segment 8 vein is performed to create a single orifice for single outflow reconstruction with the recipient's RHV or vena cava. Of 35 venoplasties, 2 developed hepatic venous stenoses which were promptly managed with percutaneous interventional radiologic procedures. No graft was lost due to hepatic venous stenosis. In conclusion, these techniques avoid interposition grafts, are easily performed at the back table, simplify graft-to-recipient cava anastomosis, and avoid venous outflow narrowing.     

Cryopreserved aortic quilt plasty for one-step reconstruction of multiple hepatic venous drainage in right lobe living donor liver transplantation

Hepatic venous outflow should be maintained for the success of living right lobe liver transplantation. In cases when the right hepatic vein is not the dominant venous drainage, the anterior branch of the middle hepatic vein and the accessory hepatic veins should be adequately drained to preserve graft function. One-step reconstruction of the hepatic veins became a preferred technique to create separate outflow for each of the graft's veins. In this report, we have described a quilt plasty technique for 1-step reconstruction of living donor hepatic veins using cadaveric cryopreserved aorta and iliac vein grafts.     

Complex outflow anatomy in left lateral lobe graft and modified venous reconstruction in pediatric living donor liver transplantation

Hepatic venous outflow reconstruction is of critical significance in pediatric patients undergoing living donor liver transplantation. Accurate knowledge of the anatomical variations is important to obtain appropriate size segmental grafts. The diameter of the hepatic veins and the potential risk of complications at the level of the anastomosis require an adequate primary vascular reconstruction. We describe a venous outflow reconstruction technique, in a living related left lateral lobe graft, with unfavorable hepatic venous anatomy.     

150例活体肝移植供肝的后台修整

目的 总结150例活体供肝的后台修整经验.方法 回顾性分析2007年2月至2008年5月间完成的150例活体供肝的修整资料.结果 150例供肝中,包含肝中静脉及尾状叶的左半肝3例,肝左静脉与肝中静脉成形;左外侧叶2例;带肝中静脉右半肝67例,肝右静脉与肝中静脉成形;不带肝中静脉右半肝78例.78例不带肝中静脉右半肝中23例未进行S_5、S_8静脉的重建,供肝血流恢复后S_5、S_8肝组织均有不同程度的淤血.其余55例用不同材料重建S_5、S_8静脉:新鲜尸体髂静51例,受体大隐静脉1例,受体曲张脐静脉1例,受体肝内门静脉1例,受体肝静脉1例.145例右半肝供肝中门静脉为C型的7例,均成形为一个开口.结论 HTK是活体供肝的最佳灌注、保存液,供肝流出道恰当的成形、重建不但可简化供肝植入的操作步骤,还可最大限度的保护有功能的肝组织,是受体术后顺利恢复的关键.     

Techniques of reconstruction of hepatic veins in living-donor liver transplantation, especially for right hepatic vein and major short hepatic veins of right-lobe graft

Living-donor liver transplantation (LDLT) is now widely accepted as a therapeutic option for adult patients with acute and chronic end-stage liver disease. In the early period, the left lobe was the major liver graft used in adult LDLT to ensure donor safety, especially in Eastern countries. However, the frequent extremes of graft-size insufficiency in left-lobe LDLT represented a greater risk of small-for-size graft syndrome in the recipient, which has focused attention on transplantation of the right lobe from a living donor. The major concern of right-lobe LDLT has focused on its safety for the donor and the necessity for including the middle hepatic vein (MHV) in the graft to avoid congestion of the right anterior segment. The MHV carries out important venous drainage for the right anterior segment and is essential for perfect graft function. The decision of whether to take the MHV with the liver graft (extended right lobe graft) or whether to retain it in the donor, with reconstruction of the MHV tributaries in the liver graft (modified right lobe graft) has been extensively discussed in numerous studies. However, adequate right hepatic vein and major short hepatic vein (middle and inferior right hepatic vein [RHV]) drainage of the liver graft is perhaps equally important as MHV outflow drainage for the integrity of right-lobe graft function. Herein, the author describes various techniques of venoplasty of the right hepatic vein (RHV) and the major short hepatic veins to obviate venous outflow obstruction in these veins.     

Reconstruction of middle hepatic vein in living donor liver transplantation with modified right lobe graft: a single center experience

Although a right liver graft without the middle hepatic vein (MHV) can cause congestion in the anterior segment, the reconstruction of MHV tributaries and the complex procedure remain controversial. Between November 2006 and October 2007, right liver transplantation without the MHV was performed in 31 cases. A retrospective analysis was conducted on clinical data and two groups were formed: with MHV reconstruction (Group I, n  = 16) and without MHV reconstruction (Group II, n  = 15). We analyzed the serum liver function markers at 3 weeks postoperatively and evaluated vascular flow in the graft and interpositional vein daily by Doppler ultrasonography during the hospital stay and monthly follow-up after discharge. One patient (6.7%) died of liver congestion and acute hepatic rejection on the postoperative day 10 in Group II. Congestion was observed in another three cases (20%) of Group II and one case (6.25%) of Group I. The levels of alanine transferase and aspartate transferase in Group II was higher than those in Group I in the first week after transplantation, albeit not significantly. In Group I, most of the interpositional vein grafts were the recipient's portal veins. Venoplasty in the graft was performed in three cases. All the interpositional veins and tectonic outflow orifices were detected to be patent by ultrasonography within 14 days after transplantation. The reconstruction of the MHV tributaries is necessary in the right liver graft without MHV according to our policy and better criteria for MHV reconstruction should be established. The recipient's portal vein is an optimal choice for the interpositional vein and hepatic venoplasty in living donor liver transplantation can simplify the operation and ensure excellent venous drainage.     

Hepatic Venous Outflow Reconstruction in Right Lobe Living-Donor Liver Graft Using Recipient''s Superficial Femoral Vein

Venous congestion of a liver graft from a life donor is a disastrous complication with a high risk of graft failure. For safety reasons, the middle hepatic vein (MHV) is currently unanimously left with the donor. As this vessel provides major venous draining of the right anterior sector, reconstruction of significant MHV tributaries is controversial. We describe here successful venous outflow reconstruction in adult-to-adult right lobe living-donor liver transplantation (RL-LDLT) using the recipient's superficial femoral vein (SFV). Six months after transplantation, graft function and perfusion are excellent, and the patient is free of venous morbidity related to the harvest of the SFV.     

Superior vena cava graft for right liver and right lateral sector transplantation

BACKGROUND: The usefulness of cryopreserved superior vena cava (SVC) grafts for venous reconstruction remains to be evaluated in right liver and right lateral sector transplantation. METHODS: Reconstruction of the hepatic vein was performed when the congested area in the liver graft was significant. A vein graft with a suitable shape and length meeting the demands for the venoplasty was selected, and SVC grafts were used in 20 recipients. Surgical techniques were classified into five types according to the necessity of middle or short hepatic vein reconstruction in the liver graft. Surgical outcomes and vein graft patency were evaluated. RESULTS: All 20 recipients survived the operation without any complications caused by congestion. Liver functions were well recovered in the early postoperative period. The 1-year primary patency rates of cryopreserved vein grafts used for reconstructed right hepatic veins, inferior right hepatic veins, and middle hepatic vein tributaries were 100%, 94%, and 42%, respectively. CONCLUSIONS: SVC grafts were feasible for outflow tract reconstruction in right liver and right lateral sector transplantation, although the long-term patency of the grafts for middle hepatic vein reconstruction remains to be evaluated.     

Utility of Polyethylene Terephthalate (Dacron) Vascular Grafts for Venous Outflow Reconstruction in Living-Donor Liver Transplantations

BackgroundVenous outflow reconstruction of modified right-lobe liver grafts has been shown to prevent the occurrence of graft congestion and subsequent complications, including graft loss. In the present study, we aimed to investigate the safety and efficacy of Dacron grafts for venous reconstruction in living donor liver transplantation (LDLT).MethodsBetween January 2016 and January 2018, Dacron grafts were used in 148 liver transplants. Of these, 104 patients who had a follow-up computerized tomography (CT) scan were enrolled into the study. A total of 179 outflow hepatic veins including V5, V8, partial middle hepatic vein, and accessory inferior right hepatic veins (IRHV) were reconstructed using synthetic Dacron grafts. Graft patency was evaluated with both intraoperative Doppler ultrasonography following reconstruction, and a follow-up CT was performed on the postoperative day 7 (±1). Retrospective data collection included demographics, parameters for small-for-size (laboratory tests [bilirubin, International Normalized Ratio] and ascites) syndrome, postoperative morbidity, and mortality.ResultsFollow-up CT revealed graft patency in 155 out of 179 (86.6%) vascular grafts. Postoperative seventh-day patency rates for each reconstructed vein were as follows: V5, 87.5% (70/80); V8, 87.7% (50/57); partial middle hepatic vein, 100% (11/11); and IRHV, 77.4% (24/31). No major graft-related complications (early graft dysfunction, graft infection) or graft-related mortality were observed. None of the recipients developed small-for-size syndrome based on laboratory tests and clinical findings.ConclusionsDacron vascular grafts appear as an advantageous and useful alternative for venous outflow reconstruction in LDLT.     

The role of hepatic veins in liver operations

In this report we review the role of the hepatic veins in resective operations of the liver. Emphasis is placed on the distribution of the hepatic veins, their relationship to hepatic arterial and portal venous inflow tracts, and the drainage patterns of hepatic lobules. An extensive review of the older literature has emphasized the necessity to preserve hepatic venous drainage for the various hepatic segments to prevent postoperative liver congestion and injury. Recent experimental and clinical reports have identified the mechanisms through which hepatic vein obstruction can be well tolerated. These mechanisms include interlobar and interlobular collateral development, reversal of blood flow in the portal vein with conversion of the portal vein to an outflow tract, development of extrahepatic collaterals, drainage through the caudate lobe, and increased lymphatic draining to relieve hepatic congestion.     

成人间活体肝移植后小肝综合征的预防：附6例报告

目的：探讨预防成人间活体肝移植术后小肝综合征（SFSS)的方法。 方法：回顾性分析6例成人间活体肝移植(LDLT)的临床资料,包括受体术前血细胞计数、脾脏厚度、门静脉直径、移植物重量与受体体重比（GRWR）、移植物体积与受体标准肝体积比（GV/SLV）及肝静脉重建等,探讨合适体积移植物、良好肝静脉回流、及正常门静脉灌注对SFSS的预防作用。 结果：受体术前均无严重门静脉高压,均没有采用降门静脉压力与血流的措施,6例肝移植物GV/SLV均大于40%,除1例GRWR为0.74%外,余均大于0.8%。6例受体肝静脉重建均良好,重建后肝脏无淤血改变。术后无SFSS发生。 结论：LDLT通过选择合适体积移植物,重建良好的肝静脉回流,控制门静脉压力,防止门静脉过度灌注等有助于预防SFSS的发生。     

New hepatic vein reconstruction in left liver graft.

The incidence of hepatic venous stenosis is higher in partial liver transplantation. New methods for hepatic venous reconstruction in left liver transplantation, which secure wide anastomosis, were devised and are reported here. In the graft, the right side of the middle hepatic vein or the left side of the left hepatic vein was cut longitudinally and a rectangular-shaped vein patch was attached for venoplasty. In the recipient, after the left and middle hepatic veins were joined, the right side of the middle hepatic vein was cut toward the closed right hepatic vein, making a horizontal cavotomy for anastomosis. Of 92 patients who underwent conventional hepatic vein reconstruction, 3 were complicated by hepatic venous stenosis (median follow-up 43 months). By contrast, there were no hepatic vein complications in the 20 patients who underwent the new technique (7 months). The current method appears to be technically feasible for outflow reconstruction in left liver graft transplantation.     

Hepatic venoplasty in living-donor liver transplantation using right lobe graft with middle hepatic vein

Inclusion of the middle hepatic vein in a right lobe graft from a living-donor may improve venous drainage and avoid graft dysfunction, but reconstruction of the middle hepatic vein is technically difficult. We developed a hepatic venoplasty technique, which was applied in eight consecutive right lobe liver transplantations. The right and middle hepatic veins of the graft were joined together to form a triangular cuff for a single anastomosis to the recipient's inferior vena cava. Hepatic venoplasty was successful in all cases, and no interposition graft was required. Venovenous bypass was not used. All grafts showed immediate function, and no hepatic venous outflow obstruction was observed. There was no reoperation and the graft survival rate was 100%. This hepatic venoplasty technique can be applied systemically as a standard one in right lobe liver graft with the middle hepatic vein to simplify the recipient hepatectomy and to obviate venous outflow obstruction.     

Life-Threatening Portal Flow Steal Reappearing Under Increased Intrahepatic Vascular Resistance After Living Donor Liver Transplantation

Maintenance of adequate portal inflow is crucial for graft regeneration in adult living donor liver transplantation (ALDLT) to allow the recipients to meet their early metabolic demands. A persistent large spontaneous portosystemic shunt can divert portal flow away from the liver graft, leading to impaired or delayed graft regeneration and subsequent graft failure. The importance of obliterating huge portosystemic shunt during liver transplantation is obvious for successful ALDLT. However, in partial liver graft with a relatively small graft-to-recipient weight ratio (GRWR) (compared with deceased donor whole graft liver transplantation), even the persisting small portosystemic shunt may result in repeated portal flow steal when a liver graft faces increased intrahepatic vascular resistance caused by rejection or graft congestion with hepatic venous outflow stenosis. We present 2 complicated cases of reappearing portal flow steal that were derived from the remaining small portosystemic shunt under the increased vascular resistance of the liver graft, even after interruption of a large portosystemic shunt during ALDLT. Because ALDLT is always a partial liver graft, even when GRWR is over 1%, it is much more vulnerable to hemodynamic changes in portal flow by rejection or graft congestion by hepatic venous outflow obstruction. Therefore, a comprehensive understanding of complex portosystemic shunt and complete reinterruption of reappearing portosystemic shunt, even though small and insignificant, during ALDLT is important for graft salvage procedures before irreversible liver graft damage.     

Pathophysiology and strategy for small-for-size graft syndrome after living-donor liver transplantation

Small-for-size (SFS) graft syndrome is an important problem after living-donor liver transplantation in adults. Hemodynamic change is thought to be the main cause of graft injury. Excessive portal flow is associated with hepatic sinusoidal injury, and reduction of portal flow improves postoperative liver function. Increased venous outflow due to hepatic venoplasty or reconstruction of the middle hepatic vein decrease the risk of graft congestion. However, the intragraft acute-phase response remains unclear. Recent studies have revealed that downregulation of heat shock protein (HSP) may account for SFS graft injury, and induction of HSP may prevent SFS syndrome. On the other hand, derangement in the regulation of liver regeneration is recognized as another important factor. Further investigation of the regulatory mechanisms of liver regeneration in SFS grafts may suggest a strategy for the prevention and treatment of SFS syndrome. Successful transplantation of marginal-size liver grafts would improve outcome for recipients and increase the margin of safety for living donors.     

Experience with recipient's superficial femoral vein as conduit for middle hepatic vein reconstruction in a right-lobe living donor liver transplant procedure

Middle hepatic vein reconstruction during the right-lobe living donor liver transplant procedure has been recognized to be a significant factor. We initially reconstructed only a single middle hepatic vein orifice draining into segment 8. In cases where the right-lobe liver graft has several major middle hepatic vein tributaries, including veins draining segment 5 that are remote from the right hepatic vein orifice, a long and thick interposition conduit is necessary for reconstruction. Among 11 consecutive adult patients who received a right-lobe liver graft without a middle hepatic vein at our institution, 8 underwent reconstruction of all major middle hepatic vein tributaries using a vein graft from the recipient's superficial femoral vein. The remaining 3 patients had no major middle hepatic vein tributaries. Posttransplant-computed tomography imagings showed increased liver mass with a patent superficial femoral vein graft in 8 patients. In the absence of a venous system from a deceased donor, a recipient superficial femoral vein offers an excellent size match to maintain the venous outflow of middle hepatic vein tributaries. Reconstruction with recipient superficial femoral vein plays an important role in maximizing liver function and minimizing morbidity in the early posttransplant period.     

Reconstruction of hepatic or portal veins by use of newly customized great saphenous vein grafts

Background and aims Segmental resection of major hepatic veins or the portal vein is sometimes required if one is to secure adequate surgical margins from hepatic or pancreatic malignancies. An external iliac vein is widely sacrificed as a vein graft to replace the defect, but this is associated with postoperative edema of the lower leg. We developed a new method for constructing the great saphenous vein to interpose the hepatic or portal veins.Patients and methods The great saphenous vein was divided transversely into three sections, which were aligned side-to-side. The three pieces were anastomosed to make a sheet 3 × 2 cm, which was rolled up into a cylindrical form of approximately 1 cm in diameter and 2 cm in length. We applied the finished vein grafts to interpose the major hepatic veins in three patients with metastatic liver tumors and the portal vein in two patients with pancreatic malignancies in cylindrical form and to reconstruct the portal vein in one patient with a pancreas cancer, using a three-row sheet as a patch graft.Results No patient developed venous thrombosis of the graft or edema of the lower leg.Conclusions The newly customized vein graft was safe and useful for the reconstruction of the major hepatic or portal veins.     

Hepatic venoplasty to overcome outflow block in living related liver transplantation

A 14-year-old boy with congenital biliary atresia underwent living related liver transplantation. Because of anatomic variation in donor hepatic vein, there were small and double orifices of hepatic veins in the harvested left hemiliver graft. To minimize the risk of outflow block after reperfusion, the recipient’s native hepatic vein was used as an autologous patch for hepatic vein reconstruction. After 3 years of follow-up, the patient is alive and well with normal liver function. Follow-up duplex ultrasound scan showed adequate hepatic vein outflow without signs of late obstruction. The new technique of the autologous vascular patch grafting for successful hepatic vein reconstruction is described.     

Relation between Hepatic and Portal Veins in the Right Paramedian Sector: Proposal for Anatomical Reclassification of the Liver

Although a right liver graft without a middle hepatic vein resulted in potential venous congestion in the right paramedian sector, the details of the hepatic venous distribution in the right paramedian sector have not been established. In this study, the ramification patterns of the hepatic veins draining the right anterosuperior segment (S8) and the relation between the hepatic and portal veins were assessed using multislice computed tomography in 44 patients without lesions in the liver. All 52 drainage veins of the ventral area of S8 joined the middle hepatic vein, and all 48 drainage veins of the dorsal area joined the right hepatic vein. The hepatic vein crossing between the ventral and dorsal areas was observed in each patient examined. Therefore, we propose a reclassification wherein the right paramedian sector is divided into ventral and dorsal segments. This new classification may contribute to the development of new and safer surgical procedures, including more limited resection and right lobe adult living donor liver transplantation to avoid graft congestion.