活体肝移植后小肝综合征的研究进展

小肝综合征是活体肝移植术（LDLT）后的严重并发症,供体年龄、脂肪肝程度、受体术前疾病状态（MELD评分）、术后高门静脉灌注、流出道不畅及移植物大小和质量等均小肝综合征的发生起着重要作用。术前选择最佳的供体;术中行脾脏切除或脾动脉结扎或对门静脉限流,保证流出道的绝对通畅;术后及早发现并积极治疗能显著减少小肝综合征的发生。     

术中监测及调整门静脉血流预防活体肝移植术后小肝综合征

目的探讨活体肝移植术中门静脉血流量及门静脉压力的监测及调整对小肝综合征的预防作用。方法回顾性分析我院移植一科2007年10月至2008年10月期间行活体肝移植并进行术中门静脉血流监测的44例患者的临床资料,包括实测供肝重量占受者体重比(GRWR)、门静脉血流量及压力、术后是否出现小肝综合征表现等。对于实测GRWR偏小(GRWR1%)的病例,如果术中门静脉压力12 mm Hg(1 mm Hg=0.133 kPa)或者门静脉血流量250 ml/(min.100 g),在术中加行脾切除或脾动脉结扎,分析监测和调整门静脉血流(脾切除和脾动脉结扎)是否可以预防小肝综合征的发生。结果行脾切除6例,切脾后门静脉血流量及压力均较切除前明显降低(P0.05);脾动脉结扎7例,结扎后门静脉压力较结扎前明显降低(P0.05),而门静脉血流量无明显变化(P0.05)。术后44例患者均未出现小肝综合征表现。结论活体肝移植术中通过切脾或行脾动脉结扎降低移植肝门静脉血流量及压力对术后小肝综合征有预防作用     

预防活体肝移植后肝小体积综合征的综合措施

目的 通过术前选择合适的供肝、术中建立充分的流出道及术后调整门静脉压等综合措施预防活体肝移植术后肝小体积综合征.方法 总结2007年12月至2009年11月的113例活体肝移植的临床资料,术前通过影像系统评估供肝体积,测算供肝体积与受者体重比(GRWR),根据供肝解剖及GRWR确定采用的供体类型(含肝中静脉右半肝,不含肝中静脉右半肝,含肝中静脉左半肝等),术中通过建立充分的流出道,根据GRWR、术前脾功能亢进情况、肝动脉开放后门静脉血流量及门静脉压力,确定是否采用脾动脉结扎等方法将门静脉压力控制在＜20 mm Hg(2.67 kPa),门静脉血流量控制在＜250 ml·min-1·100 g-1,观察采取上述措施后肝小体积综合征的发生情况.结果 75例受者接受含肝中静脉的右半肝,37例接受不含肝中静脉的右半肝,1例接受含肝中静脉左半肝.随访6个月,所有受者均未出现持续黄疸、败血症等严重的肝小体积综合征表现,1例受者于术后42 d死于脑卒中及呼吸衰竭,受者术后6个月存活率为99.1％(112/113).结论 术前根据供肝血管解剖及GRWR选择适当的供肝类型,术中建立充分的流出道,通过脾动脉结扎等方式调整门静脉血流及压力的综合方法可有效预防肝小体积综合征.     

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。     

活体肝移植术后供体胆漏的诊治体会

目的总结活体肝移植术后供体胆漏的诊治经验。方法回顾性分析95例活体肝移植供体的临床资料,了解术后胆漏并发症发生情况,重点分析胆漏并发症供体的临床表现、处理方法及治疗效果。结果95例肝移植供体术后发生胆漏9例,胆漏的发生率为9%。9例胆漏供体的供肝部位均为左外叶,均为肝断面迟发型胆漏,临床表现无典型胆汁性腹膜炎表现,血清胆红素升高。给予经皮穿刺引流或保留引流管处理后均治愈,无二次手术及死亡病例。结论活体肝移植供体术后应注意监测供体肝功能及肝动脉血流动力学变化,对并发胆漏的供体予以积极治疗,预后良好。     

活体肝移植后小肝综合征4例

目的:探讨活体肝移植后小肝综合征的病因及其诊治。方法:结合文献,回顾性分析4例小肝综合征的临床特点及治疗经验。结果:4例均有高胆红素血症,2例出现顽固性腹水,最终2例死亡,1例经保守治疗治愈,1例经急诊再次肝移植后治愈。结论:小肝综合征是活体肝移植术后严重并发症,诊治较困难;术前CT评估体积并不能绝对避免小肝综合征的发生;严重者需行再次肝移植。     

活体肝移植供体手术及术后管理（附22例临床分析）

目的 探讨提高活体肝移植供体手术安全性和加强术后管理的措施。方法 回顾性分析北京大学人民医院2003年2月至2009年6月22例活体肝移植供体的临床资料,总结供体术前评估、手术技术、术后并发症及随访情况。结果 术前对供体进行三步法评估,术中采用超吸刀 （CUSA）进行肝脏实质分离,术后定期随访。供肝移植物包括肝左外叶2例、左半肝6例、扩大左半肝1例、右半肝5例和扩大右半肝8例。1例在术后早期出现腹腔内出血,1例合并胸水,1例枕后皮下血肿,其他供体未出现严重并发症,术后肝功能迅速恢复正常,随访至今无供体死亡。结论 活体肝移植供体手术复杂,严格术前评估,术中精细操作,术后加强随访是提高活体肝移植供体安全的重要保证。     

活体肝移植的几点关键外科技术

目的：探讨活体肝移植的几点关键外科技术。方法：2001年1月至2002年3月底,实施活体肝移植11例,其中左半肝8例,左外叶1例,成人右半肝2例;根据术前CT、血管造影和术中B超确定肝切除线,超声电刀离断肝实质,经门静脉灌注原位获取。受体手术采用保留腔静脉的全肝切除。移植肝原位植入,肝静脉重建采用扩大成型吻合技术,显微技术吻合肝动脉,胆道重建采用端端吻合,置“T“管引流。结果：11例供体术后顺利康复出院,未发生严重并发症。11例受体中,1例发生肝动脉血栓形成需再次肝移植,1例因不可逆转的严重排斥反应,于术后72d死亡。10例受体康复出院,肝功能、铜氧化酶恢复正常。结论：活体肝移植对供体是相对安全的。管道重建技术是活体肝移植的重要环节。术前、术中了解供体的解剖变异并正确处理,可降低并发症发生率。     

活体肝移植术中门静脉血流量检测与调整预防小肝综合征

目的：探讨活体肝移植术（living donor liver transplantation,LDLT）中测定与调整门静脉血流量对小肝综合征（small-for-sizesvndrome,svss）的预防作用。方法：回顾性分析我中心2007年9月至2008年3月行门静脉血流测定的31例LDLT病例资料,包括移植物重量／受体体重（GRWR）、门静脉血流量及术后小肝综合征发生率,探讨检测和调整LDLT中行脾切除及睥动脉结扎病人的门静脉血流量对预防小肝综合征的作用。结果：8例LDLT术中同时行脾切除术,切脾后门静脉血流量较切脾前明显降低（P〈0．01）。5例LDLT术中同时行脾动脉结扎,结扎后门静脉血流量亦较前减低（P=0．017）。行门静脉血流调整组（13例）的GRWR低于未调整组（18例）（P=0．044）;而门静脉血流量则明显高于未调整组（P〈0.001）。调整组无小肝综合征发生,未调整组发生1例小肝综合征。结论：LDLT术中通过脾切除或行脾动脉结扎者降低了移植肝门静脉血流量,有预防术后小肝综合征的作用。监测门静脉血流量为指导门静脉血流调整提供了较客观的依据。     

影像学检查在成人活体肝移植术后小肝综合征中的应用

小肝综合征（SFSS）是成人活体肝移植术后一种发病率和死亡率都很高的临床并发症。目前如何有效防治SFSS已成为研究热点。除改进外科技术外,影像学检查在成人活体肝移植术后SFSS的预防、检测及治疗方面也发挥着越来越重要的作用。本文对影像学检查在成人活体肝移植术后小肝综合征中的应用作一综述。     

Review of the surgical approach to prevent small-for-size syndrome in recipients after left lobe adult LDLT

Left lobe liver grafts increase the donor safety in adult-to-adult living-donor liver transplantation (ALDLT). However, the left lobe graft provides about 30–50 % of the required liver volume to adult recipients, which is insufficient to sustain their metabolic demands, which can lead to small-for-size syndrome (SFSS). Transient portal hypertension and microcirculatory hemodynamic derangement, apart from outflow obstruction, during the first week after reperfusion are the critical events associated with small-for-size graft transplantation. The incidence of SFSS in left lobe ALDLT can be decreased by increasing the left lobe graft volume by effective utilization of the caudate lobe with preserved vascular supply, by modulating the portal pressure with splenectomy or a porto-systemic shunt or by hepatic venous outflow reconstruction to prevent the development of venous congestion. In this review, we discuss the pathophysiology of SFSS and the various surgical strategies that can be performed to prevent SFSS in an effort to enhance the donor safety during living-donor liver transplantation.     

Small for size syndrome following living donor and split liver transplantation

The field of liver transplantation is limited by the availability of donor organs. The use of living donor and split cadaveric grafts is one potential method of expanding the donor pool. However, primary graft dysfunction can result from the use of partial livers despite the absence of other causes such as vascular obstruction or sepsis. This increasingly recognised phenomenon is termed "Small-for-size syndrome" (SFSS). Studies in animal models and humans have suggested portal hyperperfusion of the graft combined with poor venous outflow and reduced arterial flow might cause sinusoidal congestion and endothelial dysfunction. Graft related factors such as graft to recipient body weight ratio < 0.8, impaired venous outflow, steatosis > 30% and prolonged warm/cold ischemia time are positively predictive of SFSS. Donor related factors include deranged liver function tests and prolonged intensive care unit stay greater than five days. Child-Pugh grade C recipients are at relatively greater risk of developing SFSS. Surgical approaches to prevent SFSS fall into two categories: those targeting portal hyperperfusion by reducing inflow to the graft, including splenic artery modulation and portacaval shunts; and those aiming to relieve parenchymal congestion. This review aims to examine the controversial diagnosis of SFSS, including current strategies to predict and prevent its occurrence. We will also consider whether such interventions could jeopardize the graft by compromising regeneration.     

Posterior cavoplasty: a new approach to avoid venous outflow obstruction and symptoms for small-for-size syndrome in right lobe living donor liver transplantation

Purpose  

A common and serious problem after living donor liver transplantation (LDLT) of small grafts is small-for-size syndrome (SFSS). Although hyperdynamic portal inflow and portal hypertension are cornerstones in the development of SFSS, inadequate outflow may aggravate SFSS. Therefore, enlargement of the portal outflow tract by incision of the anterior rim of the orifice of the right hepatic vein (RHV) has been advocated for right lobe LDLT. But backwards tilt of a small graft into a large abdominal cavity may lead to a choking of the otherwise large anastomosis and thus we propose posterior enlargement of the orifice of the RHV.     

Small‐for‐size syndrome in live donor liver transplantation—Pathways of injury and therapeutic strategies

Due to the severe organ shortage and the increasing gap between the supply and demand for donor grafts, live donor liver transplantation (LDLT) has become an accepted and alternative technique for the expansion of the donor pool. However, donor safety and good recipient outcomes must be balanced regarding risk stratification and decision‐making within this patient population. Small‐for‐size syndrome (SFSS) is one of the complications encountered after LDLT, thus increasing the burden of optimizing donor graft selection and effective treatments during its occurrence. A graft‐to‐recipient weight ratio (GRWR) <0.8 predisposes the graft to SFSS. However, other factors may induce this complication even without a graft‐to‐patient size mismatch. Several strategies to prevent this complication include portal vein flow and liver outflow modulation, as well as pharmacological treatment. Also, as an entity with a multifactorial etiology, outcomes vary between right‐lobe, left‐lobe, and posterior‐lobe donation among series encountered in the literature. In this review, we analyze the pathophysiology and classification of this complication, the state‐of‐the‐art on management of SFSS, and the outcomes regarding the best treatment strategy on this patient population.     

New prediction factors of small‐for‐size syndrome in living donor adult liver transplantation for chronic liver disease

Small‐for‐size syndrome (SFSS), which is characterized by synthetic dysfunction and prolonged cholestasis, is a major cause of worse short‐term prognoses after living donor adult liver transplantation (LDALT). However, the risks of SFSS remain unclear. The aim of this study was to clarify the risks of SFSS, which were analysed in 172 patients who underwent LDALT for chronic liver disease. Graft types included left lobe with caudate lobe graft (n = 110) and right lobe graft (n = 62). Thirty‐four cases (24 with left lobe grafts and 10 with right lobe grafts) were determined as SFSS. SFSS developed even if the actual graft‐to‐recipient standard liver volume ratio was >40%. Logistic regression analysis revealed three independent factors associated with SFSS development in left and right lobe grafts: donor age, actual graft‐to‐recipient native liver volume ratio, and Child’s score. Donor age and actual graft‐to‐recipient native liver volume ratio may become predictive factors for SFSS development in left and right lobe grafts in patients undergoing LDALT.     

小肝综合征(SFSS)的研究进展

小肝综合征(small-for-size syndrome,SFSS)是成人间活体肝脏移植(living donor liver transplantation,LDLT)最严重的并发症,也是成人间LDLT预后差的重要原因,其确切概念和发病机制尚未统一,存在广泛的争议.本文对其主要发病机制的研究进展作了概括,归纳了相关预防和治疗方案,包括:术前供者和移植物的选择、降低门静脉高灌注、双肝移植技术的应用、分子药物的应用及其他创新技术的使用等五个方面.同时,对其未来的研究方向提出了相关见解.

Abstract：

The small-for-size syndrome (SFSS) is widely recognized as one of the most serious clinical complications. It substantially contributes to a poor prognosis after adult living donor liver transplantation. Currently, there is still no consensus on the exact definition and pathogenesis of SFSS. We reviewed the progress on research of pathogenesis of SFSS and put forward some relevant preventive and treatment measures, including donor selection, graft assessment, reduction of high portal vein perfusion, dual grafts technology, advanced molecular medicine and other innovative approaches. Also, we offered some relevant insights into the future research directions of SFSS.     

Small-for-size syndrome secondary to outflow block of the segments V and VIII anastomoses--successful treatment with trans-splenic artery embolization: a case report

Despite the rapid expansion of living donor liver transplantation (LDLT) in the adult population over the last few years, small-for-size syndrome (SFSS) has emerged as an important clinical problem. We have herein reported a patient who developed clinical evidence of prolonged cholestasis and intractable ascites after a small-for-size right lobe LDLT. The SFSS was attributed to outflow block of segments V and VIII anastomoses with severe portal overperfusion injury. It was successfully treated by reduction of portal pressure and blood flow after trans-splenic arterial ligation. We recommend that trans-splenic artery embolization, a technically simple procedure, be applied to treat portal overperfusion injury in SFSS.     

门静脉-下腔静脉吻合术预防活体肝移植术后小肝综合征3例报道

目的探讨门静脉-下腔静脉吻合术用于预防活体肝移植术后小肝综合征(small-for-size liver syndrome,SFSS)的效果。方法 3例活体肝移植均采用不含肝中静脉的右半肝作为移植物。术中发现实测移植物(肝)重量/受体的体质量(体重)的比值(graft to recipient weight ratio,GRWR)为0.58%、0.77%及0.71%,均<0.8%,符合小移植物的诊断。处理:首先吻合肝静脉流出道,其次吻合门静脉,将受体门静脉右支与移植肝门静脉右支端端吻合,将受体门静脉左支与下腔静脉行端侧吻合达到门腔分流的作用,之后按顺序吻合动脉和胆道。术中均未行脾静脉结扎或脾切除等处理。术后定期随访。结果 3例患者术后均未发生SFSS并顺利出院,出院时间分别为术后25d、34d及56d。移植肝功能逐步好转,术后1d门静脉流速理想。移植肝增长良好。门静脉-下腔静脉短路通畅时间:除1例通畅持续仅104d,其余2例持续通畅。结论 LDLT术中进行门静脉-下腔静脉吻合术可以及时有效预防小移植物背景下的SFSS,受体门静脉左支与下腔静脉行端侧吻合的分流技术安全可靠。     

Liver “Compliance”: A Previously Unrecognized Preoperative Predictor of Small-for-Size Syndrome in Adult Living Donor Liver Transplantation

Background

The purpose of this study was to investigate the effect of liver compliance on computed tomography (CT) volumetry and to determine its association with postoperative small-for-size syndrome (SFSS).

Patients and methods

Unenhanced, arterial, and venous phase CT images of 83 consecutive living liver donors who underwent graft hepatectomy for adult-to-adult living donor liver transplantation (ALDLT) were prospectively subjected to three-dimensional (3-D) CT liver volume calculations and virtual 3-D liver partitioning. Graft volume estimates based on 3-D volumetry, which subtracted intrahepatic vascular volume from the “smallest” (native) unenhanced and the “largest” (venous) CT phases, were subsequently compared with the intraoperative graft weights. Calculated (preoperative) graft volume-to-body weight ratios (GVBWR) and intraoperative measured graft weight-to-body weight ratios (GWBWR) were analyzed for postoperative SFSS.

Results

Significant differences in minimum versus maximum total liver volumes, graft volumes, and GVBWR calculations were observed among the largest (venous) and the smallest (unenhanced) CT phases. SFSS occurred in 6% (5/83) of recipients, with a mortality rate of 80% (4/5). In four cases with postoperative SFSS (n = 3 lethal, n = 1 reversible), we had transplanted a small-for-size graft (real GWBWR < 0.8). The three SFS grafts with lethal SFSS showed a nonsignificant volume “compliance” with a maximum GVBWR < 0.83. This observation contrasts with the seven recipients with small-for-size grafts and reversible versus no SFSS who showed a “safe” maximum GVBWR of 0.92 to 1.16.

Conclusion

The recognition and precise assessment of each individual's liver compliance displayed by the minimum and maximum GVBWR values is critical for the accurate prediction of functional liver mass and prevention of SFSS in ALDLT.     

Clinical relevance of adapting portal vein flow in living donor liver transplantation in adult patients

Size mismatching is a major concern in adult living donor liver transplantation (ALDLT). Graft hyperperfusion in these grafts is considered the main factor leading to graft dysfunction and poor survival. We describe the clinical significance of graft inflow modification (GIM) by splenic artery ligation in a series of 24 consecutive ALDLT. Between September 1999 and December 2001, 24 patients underwent ALDLT at our institution. Patients were divided into two groups: G1, n = 11 without GIM, and G2, n = 13 with GIM. Both groups were equivalent in terms of preoperative clinical state, graft characteristics, and surgical technique. Graft hyperperfusion was noticed overall, especially in small grafts (graft-to-recipient body weight ratio <0.8), with mean recipient portal vein (rPVF) values at least three times greater than those recorded in the donors. GIM permitted in G2 a significant decrease in rPVF. Small-for-size syndrome (SFSS) occurred in three (27%) patients in G1 with small grafts showing graft hyperperfusion and necessitating a retransplantation. SFSS did not occur in G2. One-year overall survival was 62% and 93% respectively for G1 and G2. It is concluded that when small-for-size grafts are accompanied by graft hyperperfusion, the rPVF should be lowered to avoid the SFSS and to improve the outcome. (Liver Transpl 2003;9:S36-S41.)